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Background: Considering the extensive use of bleaching agents and the occurrence of side effects such as enamel demineralization, this study aimed to assess the enamel changes of bleached teeth following the experimental application of chitosan-bioactive glass (CH-BG)., Methods: In this in vitro study, CH-BG (containing 66% BG) was synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thirty sound human premolars were bleached with 40% hydrogen peroxide, and the weight% of calcium and phosphorus elements of the buccal enamel surface was quantified before and after bleaching by scanning electron microscopy/ energy-dispersive X-ray spectroscopy (SEM, EDX). Depending on the surface treatment of the enamel surface, the specimens were divided into three groups (n = 10): control (no treatment), MI Paste (MI), and CH-BG. Then the specimens were stored in artificial saliva for 14 days. The SEM/EDX analyses were performed again on the enamel surface. Data were analyzed by one-way ANOVA and Tukey's test and a p-value of < 0.05 was considered statistically significant., Results: In all groups, the weight% of calcium and phosphorus elements of enamel decreased after bleaching; this reduction was significant for phosphorus (p < 0.05) and insignificant for calcium (p > 0.05). After 14 days of remineralization, the weight% of both calcium and phosphorus elements was significantly higher compared to their bleached counterparts in both MI and CH-BG groups (p < 0.05). Following the remineralization process, the difference between MI and CH-BG groups was not significant (p > 0.05) but both had a significant difference with the control group in this regard (p < 0.05)., Conclusions: The synthesized CH-BG compound showed an efficacy comparable to that of MI Paste for enamel remineralization of bleached teeth., (© 2024. The Author(s).)

Background: A novel hydrophobically modified chitosan (hm-chitosan) polymer has been previously shown to improve survival in a non-compressible intra-abdominal bleeding model in swine. We performed a 28-day survival study to evaluate the safety of the hm-chitosan polymer in swine., Methods: Female Yorkshire swine (40-50 kg) were used. A mild, non-compressible, closed-cavity bleeding model was created with splenic transection. The hm-chitosan polymer was applied intra-abdominally through an umbilical nozzle in the same composition and dose previously shown to improve survival. Animals were monitored intraoperatively and followed 28 days postoperatively for survival, signs of pain, and end-organ function. Gross pathological and microscopic evaluations were performed at the conclusion of the experiment., Results: A total of 10 animals were included (hm-chitosan = 8; control = 2). The 2 control animals survived through 28 days, and 7 of the 8 animals from the hm-chitosan group survived without any adverse events. One animal from the hm-chitosan group required early termination of the study for signs of pain, and superficial colonic ulcers were found on autopsy. Laboratory tests showed no signs of end-organ dysfunction after exposure to hm-chitosan after 28 days. On gross pathological examination, small (<0.5 cm) peritoneal nodules were noticed in the hm-chitosan group, which were consistent with giant-cell foreign body reaction in microscopy, presumably related to polymer remnants. Microscopically, no signs of systemic polymer embolization or thrombosis were noticed., Conclusion: Prolonged intraperitoneal exposure to the hm-chitosan polymer was tolerated without any adverse event in the majority of animals. In the single animal that required early termination, the material did not appear to be associated with end-organ dysfunction in swine. Superficial colonic ulcers that would require surgical repair were identified in 1 out of 8 animals exposed to hm-chitosan., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Oxidative stress plays a crucial role in steroid-induced osteonecrosis of the femoral head (SONFH). Although several antioxidant strategies have been investigated for treating SONFH, their antioxidant efficiencies and therapeutic effects remain unsatisfactory. Here, we developed a selenium nanoparticles/carboxymethyl chitosan/alginate (SeNPs/CMC/Alg) antioxidant hydrogel and evaluated its ability to treat SONFH. In vitro assays indicated that the SeNPs/CMC/Alg hydrogel exhibited excellent properties, such as low cytotoxicity, sustained SeNPs release, and favorable antioxidant activity. Under oxidative stress, the SeNPs/CMC/Alg hydrogel promoted reactive oxygen species (ROS) elimination and enhanced the osteogenic and proangiogenic abilities of bone marrow mesenchymal stem cells (BMSCs). After establishing a rabbit model of SONFH, the SeNPs/CMC/Alg hydrogel was transplanted into the femoral head after core decompression (CD) surgery. Radiographic and histological analyses revealed that the hydrogel treatment alleviated SONFH by eliminating ROS and promoting osteogenesis and angiogenesis compared to those in the CD and CMC/Alg groups. In vitro and in vivo studies indicated that the Wnt/β-catenin signaling pathway was activated by the SeNPs/CMC/Alg hydrogel in both hydrogen peroxide-conditioned BMSCs and necrotic femoral heads. These findings indicate that local transplantation of the SeNPs/CMC/Alg hydrogel is beneficial for treating SONFH, as it promotes ROS elimination and activation of the Wnt/β-catenin signaling pathway., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Geranium essential oil (GEO) has been widely used in aromatherapy and traditional medicines. Nanoencapsulation, a novel technique has emerged to overcome the environmental degradation and less oral bioavailability of essential oils. This work was undertaken to encapsulate geranium essential oil in chitosan nanoparticles (GEO-CNPs) by ionic gelation technique and to explore anti-arthritic and anti-inflammatory potential in FCA-induced arthritic model in rats. The GEO was characterized by gas chromatography flame ionization detector (GCFID) and the nanosuspension was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-rays diffraction (XRD). The Wistar albino rats (n = 32) were separated into four groups; Group 1 and 2 were considered as normal and arthritic controls. Group 3 was positive control that received oral celecoxib for 21 days while Group 4 was treated with oral GEO-CNPs after the induction of arthritis. Hind paw ankle joints diameters were weekly measured throughout the study and significant decrease (5.5 ± 0.5 mm) was observed in GEO-CNPs treatment group in comparison to arthritic group (9.17 ± 0.52 mm). Blood samples were drawn at end for evaluation of hematological, biochemical and inflammatory biomarkers. A significant upregulation of red blood cells and hemoglobin while downregulation of white blood cells, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP) and rheumatoid factor (RF) was observed. Ankles were transected for the histopathological and radiographic examination after animals were sacrificed which confirmed the alleviation of necrosis along cellular infiltration. It was concluded that GEO-CNPs were found to possess excellent therapeutic potential and promising candidates to reduce FCA-induced arthritis., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Recent findings suggest a key role for reactive oxygen species (ROS) in the pathogenesis and progression of ulcerative colitis (UC). Several studies have also highlighted the efficacy of citrate functionalized Mn 3 O 4 nanoparticles as redox medicine against a number of ROS-mediated disorders. Here we show that synthesized nanoparticles consisting of chitosan functionalized tri-manganese tetroxide (Mn 3 O 4 ) can restore redox balance in a mouse model of UC induced by dextran sulfate sodium (DSS). Our in-vitro characterization of the developed nanoparticle confirms critical electronic transitions in the nanoparticle to be important for the redox buffering activity in the animal model. A careful administration of the developed nanoparticle not only reduces inflammatory markers in the animals, but also reduces the mortality rate from the induced disease. This study provides a proof of concept for the use of nanomaterial with synergistic anti-inflammatory and redox buffering capacity to prevent and treat ulcerative colitis., (© 2023. The Author(s).)

Rheumatoid arthritis (RA) is an inflammatory condition and associated with the symmetrical synovitis of the joints and cause joint pain. The use of anti-rheumatic drugs is associated with many adverse effects. Quercetin, an important polyphenolic flavonoid, possess anti-inflammatory and anti-rheumatic effects. Quercetin use is limited due to poor absorption and bioavailability. Nanomedicines are used for the targeted drug delivery, hence it reduces the adverse effects of the drug. Based upon these factors, quercetin-loaded chitosan nanoparticles (Q-NPs) were prepared by solvent evaporation method, characterized and their better anti-rheumatic effect with mechanistic insights was validated in Freund's complete adjuvant (FCA)-induced arthritic rats along with safety studies. The animals were divided into five groups, each containing 5 animals. Group I was normal control, group II was arthritic control, while groups III, IV and V were administered with quercetin (15 mg/Kg) and Q-NPs (10 and 20 mg/Kg), respectively. The reduction in ankle diameter, serum oxidative stress markers as well as pro- and inflammatory cytokines, e.g., tumor necrosis factor (TNFα), interleukin (IL-6) were determined. The prepared Q-NPs showed hydrodynamic size of 83.9 nm, polydispersity index of 0.687, entrapment efficiency 90.5% as well as no interaction between quercetin and chitosan in Fourier transform infrared spectroscopy (FTIR). A significant reduction (p < 0.001) in ankle diameter was observed after administration of high-dose Q-NPs (4.32 ± 0.14 cm to 5.13 ± 0.62 cm). There was also reduction (p < 0.001) in levels of TNFα and IL-6 following high-dose Q-NPs (72.56 ± 2.30 and 308.19 ± 11.5 pg). The effect on biochemical tests, hematological parameters and oxidative stress parameters was also found to be significant. Histopathological changes of kidney, liver and ankle also confirmed the anti-rheumatic effect of high-dose Q-NPs. The study concludes that administration of Q-NPs (20 mg/Kg) may be used for the treatment of FCA-induced RA in rats., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Chitosan oligosaccharides (COS) show the potential to support the intestinal health, but the mechanism and role of COS-derived intestinal microbiota are unknown. We explored the protective effect of direct administration of COS on intestinal barrier function using an in vivo colitis mouse model and an in vitro enterotoxigenic Escherichia coli (ETEC)-challenged IPEC-J2 cell model. COS directly enhanced the intestinal barrier function. COS intervention also promoted the abundance and diversity of intestinal flora. Importantly, FMT intervention with a COS-derived microbiome decreased the disease index level and alleviated histopathological changes, and improved gut barrier function in the colitis model. Both COS and COS-derived microbiota suppressed ETEC-induced cellular apoptosis in IPEC-J2 cells. This study firstly confirms transplantation of COS-modified fecal microbiota can enhance the intestinal barrier function. The mechanism underlying COS benefits is due to a direct intervention by COS supplementation and an indirect improvement of the gut microbiota induced by COS exposure., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2022. Published by Elsevier Ltd.)

Chitosan has a biocompatible, biodegradable, and nontoxic nature. The effectiveness of Nano-chitosan films in the field of wound healing has been confirmed previously. The aim of this study was to compare the clinical efficacy and safety of two dressings (chitosan and nanosilver dressings) in the treatment of refractory diabetic wounds. A total of 25 eligible patients with chronic diabetic wound were included and randomly assigned to receive chitosan (13 patients) or nanosilver (12 cases) dressing. The dressings were applied on the wounds based on their protocols and patients were visited and examined by an experienced dermatologist every week. The clinical assessments and healing rates were recorded using diabetic-foot-infection (DFI) score at the 2nd, 4th, and 6th weeks during treatment. The study endpoint, safety and tolerability profile were also documented. The patterns of change in total 10-item-DFI wound scores did not differ significantly over time between the two groups. In both groups, the total 10-item-DFI wound score reduced continuously through the course of study. The mean percentage reduction of this score from baseline was 78.1% and 74.1% in the chitosan and nanosilver dressing groups, respectively. Both dressings were well tolerated and there were no adverse events. The relatively small sample size in both groups was the main limitation of the study. Our findings confirmed that chitosan may be safely and effectively used for the treatment of diabetic wounds just like the nanosilver (Acticoat TM ) dressing. Further studies are recommended with more volunteers and a longer follow-up period., (© 2022 Wiley Periodicals LLC.)

Introduction: The bioactivities of green tea extract were indicated to promote skin health in vitro. Few clinical studies reported on skin nourishment of topical applying green tea extract due to the limited skin absorption., Methods: This current study evaluated the clinical effectiveness and safety of green tea extract encapsulated chitosan microparticles (GTP) in emulsion base on a split-face, double-blind, randomized placebo-controlled study. Twenty-nine female volunteers were recruited into the study. They were randomly assigned to apply GTP and placebo creams on each half face for 8 weeks. The facial skin properties on both sides were monitored and evaluated every 2 weeks., Results: The results revealed that skin elasticity (R2) of half face treated with GTP cream (0.748 ± 0.05) was superior to another that received placebo cream (0.722 ± 0.05) at 4th week. In addition, melanin index implying skin dullness of the half face that received GTP cream significantly improved within the 6th week after application (placebo =295.60 ± 58.81, GTP =282.70 ± 59.62). Most importantly, the photographs clearly indicated that the decreasing in facial wrinkles of volunteers applied with GTP cream was more than those applying placebo cream. Signs of skin irritation were not evident in both treatment and placebo cream groups., Conclusion: Based on study outcomes, the green tea extract encapsulated chitosan microparticles appear to be the promising active candidate for promoting skin elasticity and improving skin dullness and wrinkles., (© 2021 Wiley Periodicals LLC.)

Introduction: Chitosan and curcumin are natural products that have a wide range of beneficial effects including wound healing. However, their high molecular weight and poor water solubility limit their applications., Aims: Therefore, the current study aims to evaluate the effects of chitosan (Cs) and curcumin (Cn) nanoparticles (NPs) on fibrosis and regeneration of glycerol-injured muscle., Methods: Muscle injury was induced by intramuscular injection of glycerol into the tibialis anterior muscle of rats. Cs-NPs and Cn-NPs were administered at different doses intraperitoneally after injury. Injured muscles were collected at day 7 after injury, and muscle fibrosis and regeneration were assessed., Results: The present results revealed that Cs-NPs and Cn-NPs treatment significantly decreased fibrosis index and increased the average myotube diameter with shifting of the distribution of myotube diameters towards larger diameters in a dose-dependent manner. Immunohistochemical analysis revealed that Cs-NPs and Cn-NPs treatment significantly decreased the number of CD-68 + cells and Col-1 + area. Results showed that Cn-NPs had a higher protective effect, in the form of attenuating muscle fibrosis and inflammation, and enhancing muscle regeneration, than that of Cs-NPs., Conclusions: To our knowledge, this is the first study to document the effects of Cs-NPs in injured muscles. The results of study might be a novel approach to attenuate muscle fibrosis in humans using curcumin and chitosan nanoparticles., (© 2022. The Author(s).)

Background: The transradial approach (TRA) for catheter interventions decreases vascular complications and bleeding versus transfemoral approach. Reducing time to hemostasis and preventing radial artery occlusion (RAO) following TRA are important and incompletely realized aspirations., Objectives: This first-in-human study sought to evaluate the efficacy of a novel, topically applied compound (hydrophobically modified polysaccharide-chitosan, hm-P) plus minimal required pneumatic compression, to achieve rapid radial arterial hemostasis in post-TRA procedures compared with de facto standards., Materials and Methods: About 50 adult patients undergoing 6 French diagnostic TRA procedures were prospectively enrolled. At procedure completion, a topical hm-P impregnated patch was placed over the dermotomy and TR Band (TRB) compression was applied to the access site. This patch was used as part of a novel rapid deflation protocol with a primary outcome of time to hemostasis. Photographic and vascular ultrasound evaluation of the radial artery was performed to evaluate the procedural site., Results: Time to hemostasis was 40.5 min (IQR: 38-50 min) with the majority of patients (n = 39, 78%) not requiring reinflation. Patients with bleeding requiring TRB reinflation were more likely to have low body weight and liver dysfunction, with absence of hypertension and LV dysfunction. The rate of RAO was 0% with predischarge radial artery patency documented in all patients using vascular ultrasound. One superficial hematoma was noted. No late bleeding events or cutaneous reactions were reported in the study follow-up., Conclusions: Topical application of hm-P in conjunction with pneumatic compression was safe and resulted in rapid and predictable hemostasis at the arterial puncture site., (© 2021 Wiley Periodicals LLC.)

An 8-week feeding experiment was conducted to investigate and confront the putative functions of chitosan (CTS) and chitooligosaccharide (COS) in the growth and homoeostasis of distal intestine in juvenile turbots fed diets containing soyabean meal (SBM). Three isolipidic and isonitrogenous diets were formulated by supplemented basal diet (based on a 400 g/kg SBM) with 7·5 g/kg CTS or with 2·0 g/kg COS. Our results indicated that both CTS and COS supplementation could significantly improve (i) the growth performance and feed efficiency ratio; (ii) antioxidant activity driven by metabolic enzymes (i.e. catalase, glutathione reductase, glutathione peroxidase and superoxide dismutase); (iii) glutathione levels; (iv) acid phosphatase and lysozyme activity and (v) IgM content. As a result, these two particular prebiotics were able to significantly attenuate the histological alterations due to local inflammation as well as to decrease the transcriptional levels of proinflammatory cytokines (i.e. IL-1β, IL-8 and TNF-α) and major pathway effectors (i.e. activator protein-1 (AP-1), NF-кB, p38 mitogen-activated protein kinase, c-Jun N-terminal kinase and extracellular regulated kinase). High-throughput sequencing data indicated that dietary CTS and COS could significantly decrease the diversity of intestinal bacteria but elevate the relative abundances of Bacillus, Lactobacillus and Pseudomonas genera. Altogether, these findings suggest that CTS and COS can improve growth of turbot, enhance intestinal immune and anti-oxidant systems and promote the balance of intestinal microbiota. The protective effects, elicited by these two prebiotics, against SBM-induced inflammation could be attributed to their roles in alleviating the overexpression of inflammatory cytokines by possibly down-regulating NF-кB, AP-1 and/or mitogen-activated protein kinases pathways.

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease that affects 10 to 20% of children and between 2 and 15% of the adults in Western Europe. Since 2000, therapeutic clothing or functional textiles based on silver or chitosan as antibacterial agents were introduced for AD. These agents aim to reduce skin colonization with Staphylococcus (S.) aureus. Increased colonization with S. aureus is correlated with increased AD severity. The antimicrobial effects of silver and chitosan have been demonstrated before. At this point, there is insufficient evidence for the effectiveness of antibacterial therapeutic clothing in patients with AD., Methods: This is a pragmatic randomized controlled double-blind multi-center trial comparing the effectiveness of antibacterial therapeutic clothing based on silver or chitosan as compared with non-antibacterial therapeutic clothing in patients with moderate to severe AD. A total of 165 participants, aged 0 to 80, diagnosed with moderate to severe AD are included. The study is performed in the Erasmus MC University Medical Center, University Medical Center Groningen, University Medical Center Utrecht, Amsterdam University Medical Centers, and St. Antonius Hospital Nieuwegein. Patients will be randomized 1:1:1 into one of the three intervention groups: group A will receive therapeutic clothing without antimicrobial agents, group B will receive microbial growth reducing therapeutic clothing based on chitosan, and group C will receive antimicrobial clothing based on silver. All therapeutic clothing is to be worn at night during the 12-month intervention period. Usual care is continued. The primary objective is to assess the effectiveness of antibacterial clothing (silver and chitosan group) as compared to non-antibacterial clothing assessed with the Eczema Area and Severity Index at 12 months compared to baseline. Secondary outcomes include between-group differences in physician- and patient-reported outcome measures, topical therapy use, S. aureus skin colonization, and safety. Data will be collected at baseline and after 1 month, 3 months, 6 months, and 12 months. A cost-effectiveness analysis will be performed., Discussion: This trial will provide data on the effectiveness, cost-effectiveness, and safety of antibacterial therapeutic clothing for patients with AD., Trial Registration: ClinicalTrials.gov NCT04297215. Registered on 5 March 2020., (© 2021. The Author(s).)

Injectable thermo-sensitive chitosan hydrogels have recently been developed for the use of submucosal fluids in endoscopic submucosal dissections (ESD). This study aimed to investigate the efficacy and safety of chitosan hydrogels during ESD. Submucosal fluids were administered as follows: 0.9% normal saline (NS), 0.4% hyaluronic acid (HA) and chitosan/β-glycerophosphate (CS/GP) hydrogel. Each solution was administered twice into the stomach and colon of a pig, with a total of 72 ESD procedures performed on 12 pigs. The injected volume and procedure-related parameters were recorded and analyzed. ESDs that created ulcers after 7 days were histologically compared. All ESD specimens were resected en bloc. The total injected volumes during ESD of the stomach (NS, 16.09±3.27 vs. HA, 11.17±2.32 vs. CS/GP, 9.44±2.33; p<0.001) and colon (NS, 9.17±1.80 vs. HA, 6.67±1.50 vs. CS/GP, 6.75±1.57; p = 0.001) were significantly different. Hydrogel showed significant differences from normal saline in terms of fluid power (mm2/vol; NS, 35.70±9.00 vs. CS/GP 57.48±20.77; p = 0.001) and consumption rate (vol/min; NS, 2.59±0.86 vs. CS/GP, 1.62±0.65; p = 0.013) in the stomach. Histological examination revealed preserved muscularis propria, although the chitosan hydrogel resulted in a partial inflammatory response, with a hypertrophied submucosal layer. Chitosan hydrogel was found to be superior to normal saline, with an efficacy similar to that of hyaluronic acid. Nonetheless, long-term histological changes should be evaluated before clinical implementation., Competing Interests: The authors have declared that no competing interests exist.

Objectives: Primary objectives: to compare radial artery occlusion rate (RAO) after cardiac catheterization between catecholamine-chitosan pad (InnoSEAL) and pneumatic compression device (PCD) and to compare difference in hemostasis time and radial monitoring termination time between two arms. Secondary objectives: to compare radial site bleeding and ease of use of two methods by cath-lab technicians., Background: Hemostatic pads may be an effective alternative to PCD with lesser chance of access site complications with advantage of shortened compression time., Methods: Patients (N = 606) undergoing trans-radial, diagnostic or interventional procedures were randomized to either InnoSEAL arm or PCD. RAO was assessed using US Duplex; performed 6-24 hr posthemostatic device removal. Time to hemostasis was recorded as per defined protocols. Ease of use among cath-lab technicians was assessed through 5 point Likert scale., Results: Data of 597 patients was analyzed (299 InnoSEAL, 298 PCD). RAO rate was 8.5% in InnoSEAL and 9.4% in PCD arm (p value >.05). The pooled median hemostasis time and time to termination of radial monitoring was 42 versus 225 min and 50 versus 240 min in InnoSEAL and PCD arms, respectively (p value: <.01). There was no difference in Grade I/II hematoma (InnoSEAL: 1.3% vs. PCD: 3.4%). InnoSEAL was marginally acceptable compared to PCD by technicians., Conclusion: Hemostasis time is significantly shorter in InnoSEAL arm with reasonable acceptability to its usage among cath lab staff. RAO and bleeding complications are comparable between the arms. Based on our findings, it seems feasible to include Chitosan based hemostasis pad routinely in cath lab., (© 2021 Wiley Periodicals LLC.)

This study aimed to investigate the impact of ginger extract (GE) loaded into chitosan nanoparticles (CNPs) in enhancing cytotoxicity and reducing cardiotoxicity of doxorubicin (DXN) in hepatocellular carcinoma (HCC) induced mice. DXN and GE were loaded into CNPs and cytotoxicity of loaded and unloaded drugs against HepG2 cells was evaluated. HCC was induced in male albino mice by injection of diethylnitrosamine (DINA). Mice were divided into eight groups ( n  = 15): (1) normal control, (2) DINA, (3) CNPs, (4) free DXN, (5) CNPs DXN, (6) free GE, (7) CNPs GE, and (8) CNPs DXN + CNPs GE. Both GE and DXN loaded into CNPs showed a greater decline in cell viability of HepG2 cells than the unloaded forms. GE CNPs displayed pronounced anticancer activity In Vivo through apoptosis, greater down-regulation of multidrug resistance 1, enhancement of anti-oxidant activity and depletion of vascular endothelial growth factor content in liver tissues. GE CNPs in combination with DXN CNPs showed nearly normal hepatic lobule architecture and the greatest increase in apoptotic cell count. Co-treatment group had decreased cardiac malondialdehyde, tumor necrosis factor-α and serum activity of creatine kinase and lactate dehydrogenase. Combination of GE CNPs and DXN CNPs might be a potentially effective therapeutic approach for HCC.

Nanotechnology is an emerging avenue employed in disease prevention and treatment. This study evaluated the antimicrobial efficacy of chitosan nanoparticles (CSNPs) against major bacterial and oomycete fish pathogens in comparison with chitosan suspension. Initially, the minimum inhibitory concentrations (MIC, MIC 90 ) were determined and the per cent inhibition of bacterial growth was calculated. Subsequently, the minimum bactericidal concentrations (MBCs) were determined. The time-dependent disruptions of CSNP-treated pathogens were observed via transmission electron microscopy (TEM), and the effect of CSNPs on the viability of two fish cell lines was assessed. No antimicrobial effect was observed with chitosan, while CSNPs (105 nm) exhibited a dose-dependent and species-specific antimicrobial properties. They were bactericidal against seven bacterial isolates recording MBC values from 1 to 7 mg/ml, bacteriostatic against four further isolates recording MIC values from 0.125 to 5 mg/ml and fungistatic against oomycetes recording MIC 90 values of 3 and 4 mg/ml. TEM micrographs showed the attachment of CSNPs to the pathogenic cell membranes disrupting their integrity. No significant cytotoxicity was observed using 1 mg/ml CSNPs, while low dose-dependent cytotoxicity was elicited by the higher doses. Therefore, it is anticipated that CSNPs are able to compete and reduce using antibiotics in aquaculture., (© 2020 The Authors. Journal of Fish Diseases published by John Wiley & Sons Ltd.)

A layer-by-layer (LbL) coating was designed using ionic polysaccharides (chitosan, sodium alginate, sodium hyaluronate) and genipin (crosslinker), to sustain the release of diclofenac sodium salt (DCF) from soft contact lens (SCL) materials. The coating was hydrophilic, biocompatible, non-toxic, reduced bacterial growth and had minor effects on the physical properties of the material, such as wettability, ionic permeability, refractive index and transmittance, which remained within the recommended values for SCLs. The coating was applied on a silicone-based hydrogel and on commercial SofLens and Purevision SCLs. The coating attenuated the initial drug burst and extended the therapeutic period for, at least, two weeks. Relevantly, the problems of sterilizing drug loaded SCLs coated with biopolymers, using classic methods that involve high temperature or radiation, were successfully solved through high hydrostatic pressure (HHP) sterilization., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Carboxymethyl chitosan (CMC) is widely used in food and medicine as a biodegradable polymer. However, its effects on inflammation profile and colon health are not well investigated. In the present study, CMC was given to mice to evaluate its possible effects on body weight, blood glucose level, inflammation factors, intestinal permeability and colon microbiota. Results showed that blood glucose level of CMC treated mice was relatively higher than control ones. Glucose tolerance test revealed that CMC treated mice presented higher peak glucose level and lower lag level. CMC treatment increased serum LDL-c level, decreased serum HDL-c and IL-10 level in the fat tissue. Moreover, CMC treatment downregulated the expression of tight junction protein, occludin and ZO-1, in colon as evaluated by Western blot. Colon microbiota analysis demonstrated that CMC treatment significantly decreased the OTUs and relative species abundance. The level of Enterobacteriaceae, Lachnospiraceae and several other bacteria were much higher in the colon content of CMC treated mice. The results collectively suggest that CMC treatment induces disturbance of glucose and fat metabolism, affects the inflammation profile, perturbs colon microbiota balance., (Copyright © 2019. Published by Elsevier Taiwan LLC.)

The many interesting properties of chitosan polysaccharides have prompted their extensive use as biomaterial building blocks, for instance as antimicrobial coatings, tissue engineering scaffolds, and drug delivery vehicles. The translation of these chitosan-based systems to the clinic still requires a deeper understanding of their safety profiles. For instance, the widespread claim that chitosans are spermicidal is supported by little to no data. Herein, we thoroughly investigate whether chitosan oligomer (CO) molecules can impact the functional and structural features of human spermatozoa. By using a large number of primary sperm cell samples and by isolating the effect of chitosan from the effect of sperm dissolution buffer, we provide the first realistic and complete picture of the effect of chitosans on sperms. We found that CO binds to cell surfaces or/and is internalized by cells and affected the average path velocity of the spermatozoa, in a dose-dependent manner. However, CO did not affect the progressive motility, motility, or sperm morphology, nor did it cause loss of plasma membrane integrity, reactive oxygen species production, or DNA damage. A decrease in spermatozoa adenosine triphosphate levels, which was especially significant at higher CO concentrations, points to possible interference of CO with mitochondrial functions or the glycolysis processes. With this first complete and in-depth look at the spermicidal activities of chitosans, we complement the complex picture of the safety profile of chitosans and inform on further use of chitosans in biomedical applications.

IFN-γ is an immunomodulatory factor that has been extensively studied in phenotypes of mammalian macrophages and multifarious inflammatory responses. Usually these studies relied on the classical synergistic activation of IFN-γ with LPS (LipoPolySaccharides). However, non-mammalian vertebrates, and in particular fish, are not very susceptible to LPS, and easily acquire tolerance upon repeated exposure. Therefore, for studies in fish, it is necessary to replace the classical IFN-γ+LPS immune system activation method, and find other pathogen-associated molecular patterns (PAMPs) capable of stimulating the fish immune system. Here we used an important farmed fish species, Ctenopharyngodon idella, to study the effects of CiIFN-γ2 (C. idella IFN-γ2) and chitosan (CS) on its immune responses in vivo and vitro. Our results showed that the combination of CS and CiIFN-γ2 significantly enhanced the activation of macrophages, with an activation intensity even stronger than in CiIFN-γ2 and CiIFN-γ2+LPS groups. In vivo, injection of CiIFN-γ2 could improve the survival rate of C. idella infected with Flavobacterium columnare, while a combined injection of CiIFN-γ2+CS only improved protection in the early stages after the challenge. Notably, both injections reduced the bacterial load of viscera and improved the levels of several plasma parameters (TP, T-SOD, LA, and NO). However, a dramatic up-regulation of inflammatory factors, severe inflammatory damage in the intestines and hepatopancreas, and increased mortality in late stages of infection were observed in the CiIFN-γ2+CS group. Our findings provide new insights into the macrophage activation phenotypes and inflammatory responses in fish. They also demonstrate that CiIFN-γ2 could be used as a potential immunopotentiator, but not in combination with CS. This suggests that selection of immunological adjuvants should be carefully tested experimentally., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Hemostasis following transradial arterial access (TRA) is usually achieved by mechanical compression. This study investigated if use of a chitosan-based hemostatic pad (Clo-Sur Plus Radial™) combined with mechanical compression (TR Band®) could shorten hemostasis time after TRA, compared with a TR Band® alone., Methods: 40 patients undergoing cardiac catheterization and/or percutaneous coronary intervention were assigned into 4 cohorts post TRA: 10 patients received mechanical compression with a TR Band® alone for 120 min. The other 30 patients received compression with a Clo-Sur Plus Radial™ pad combined with a TR Band® for 60 min, 45 min, and 30 min, respectively (n = 10/per cohort). Times to hemostasis and access-site complications were recorded., Results: There were no differences in patient characteristics, mean dose of heparin, or mean activated clotting time value at the end of procedure among the four cohorts. Median time to hemostasis with the TR Band® alone was 120.5 min versus 60 min, 45 min and 30 min for the 60-min, 45-min, and 30-min Clo-Sur Plus Radial™ pad combined with the TR Band® cohorts, respectively. No radial artery occlusion, late rebleeding nor hematoma was noted in this series of patients., Conclusions: In this pilot trial, use of a Clo-Sur Plus Radial™ pad in combination with a TR band® significantly shortened hemostasis time, as compared to a TR band® alone, with no increased complications noted., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Oxidized regenerated cellulose has become a major local surgical hemostatic biomaterial because of its ease of use, favorable biocompatibility, bactericidal activity and bioabsorption characteristics. Additional clinical indications of oxidized regenerated cellulose include wound repair and tissue reconstruction. Sometimes, some unusual adverse events are described. Studies report cases of minor postoperative complications as nidus of infection or allergic reaction mainly presenting as acute dermatitis, eczema and sieroma. Also, rare and serious cases of foreign body reaction or impingement on nerve, due to not optimal bioabsorption, are showed in various surgical sites. Thus, on the one hand, patients should be informed by their clinicians of the possibility of these low incidence postoperative complications when considering preparations made of cellulose derivatives; and the clinicians should clearly indicate use of this biomaterial in the surgical procedure report so that radiologists may appropriately interpret any unusual findings potentially associated with this biomaterial use and thus avoid misdiagnosis and undue alarm in the follow-up of patients. On the other hand, the biomedical carbohydrate scientist must consider effective experimental design that substantially addresses the clinical adverse events associated with carbohydrate polymer use. Optimal development of carbohydrates for clinical use depends on excellent clinician/biomedical scientist communication., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: A novel injectable expanding foam based on hydrophobically modified chitosan (HM-CS) was developed to improve hemostasis during surgeries. HM-CS is an amphiphilic derivative of the natural biopolymer chitosan (CS); HM-CS has been shown to improve the natural hemostatic characteristics of CS, but its internal safety has not been systematically evaluated. The goal of this study was to compare the long-term in vivo safety of HM-CS relative to a commonly used fibrin sealant (FS), TISSEEL (Baxter)., Methods: Sixty-four Sprague-Dawley rats (275-325 g obtained from Charles River Laboratories) were randomly assigned to control (n = 16) or experimental (n = 48) groups. Samples of the test materials (HM-CS [n = 16], CS [n = 16], and FS [n = 16]) applied to a nonlethal liver excision (0.4 ± 0.3 g of the medial lobe) in rats were left inside the abdomen to degrade. Animals were observed daily for signs of morbidity and mortality. Surviving animals were sacrificed at 1 and 6 wk; the explanted injury sites were microscopically assessed., Results: All animals (64/64) survived both the 1- and 6-wk time points without signs of morbidity. Histological examination showed a comparable pattern of degradation for the various test materials. FS remnants and significant adhesions to neighboring tissues were observed at 6 wk. Residual CS and HM-CS were observed at the 6 wk with fatty deposits at the site of injury. Minimal adhesions were observed for CS and HM-CS., Conclusions: The internal safety observed in the HM-CS test group after abdominal implantation indicates that injectable HM-CS expanding foam may be an appropriate internal use hemostatic candidate., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Different substances are combined to compensate for each other's drawbacks and create an appropriate biomaterial. A novel Polyvinyl alcohol (PVA)/chitosan (CS) porous hydrogel was designed and applied to the treatment of osteochondral defects., Methods: Hydrogels of various PVA/CS ratios were tested for physiochemical and mechanical properties in addition to cytotoxicity and biocompatibility. The hydrogels with the best PVA/CS ratio were used in the animal study. Osteochondral defects were created at the articular cartilage of 18 rabbits. They were assigned to different groups randomly (n = 6 per group): the osteochondral defect only group (control group), the osteochondral defect treated with hydrogel group (HG group), and the osteochondral defect treated with hydrogel loaded with bone marrow mesenchymal stem cells (BMSCs) group (HG-BMSCs group). The cartilage was collected for macro-observation and histological evaluation at 12 weeks after surgery., Results: The Hydrogel with PVA/CS ratio of 6:4 exhibited the best mechanical properties; it also showed stable physical and chemical properties with porosity and over 90% water content. Furthermore, it demonstrated no cytotoxicity and was able to promote cell proliferation. The HG-BMSCs group achieved the best cartilage healing., Conclusions: The novel PVA/CS porous composite hydrogel could be a good candidate for a tissue engineering material in cartilage repair.

Contact lenses (CL) provide visual correction but their use may also induce several adverse effects causative of discomfort and conditions that lead to stop or discontinue their use. Discomfort is mainly caused by insufficient wetting, impairment of the antioxidant defence system and eye infections. The current work reports on a single step sonochemical coating of CL with ZnO nanoparticles (NPs), chitosan (CS) and gallic acid (GA). GA and CS are expected to improve the comfort of CL by imparting respectively antioxidant properties and enhanced wettability, while their combination with ZnO NPs provides the CL with antimicrobial properties. The ternary composite coating presents high antibacterial efficiency (>4.5 logs reduction) against S. aureus causative of CL-related conditions, and maintains good biocompatibility (>72%) with human cell lines. The obtained multi-functionality on the CL did not affect their geometry and refractive properties., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

One of the important routes of drug administration for localized delivery of contraceptives and cervical cancer treatment agents is vaginal canal. Due to the low pH of vagina, a pH-responsive drug delivery system was developed. This hydrogel was synthesized based on a mucoadhesive biopolymer, chitosan (CS), that promotes the interaction between the hydrogel and mucosal surface of the vagina, potentially increasing the residence time of the system. This injectable hydrogel was formed via acid-labile Schiff-base linkages between free amine groups and aldehyde functionalities on modified chitosan. A novel approach was taken to add aldehyde functionalities to chitosan using a two-step reaction. Two types of slow and fast degrading hydrogels were prepared and loaded with iron (II) gluconate dihydrate, a non-hormonal spermicide, and doxorubicin hydrochloride, an anti-cancer drug. The release profiles of these drugs at different pH environments were assessed to determine the pH-dependent release mechanism. Mechanical properties, swell-ability and degradation rate of these matrices were studied. The cross-linking density of the hydrogel as well as pH changes played an important role in the characteristic of these hydrogels. The hydrogels degraded faster in lower pH, while the hydrogel with lower cross-linking density showed longer gelation time and faster degradation rate compared to the gel with higher cross-linking density. In vitro cytotoxicity assessment of these hydrogels in 48 h indicated the non-toxic effect of these hydrogels toward mesenchymal stem cells (MSCs) in the test period.

Aim: To evaluate whether a combination of isosorbide dinitrate spray and chitosan gel (10%) topically applied can have additive benefits for management of diabetic foot ulcers., Methods: In a randomized, placebo-controlled, double-blinded clinical trial, 68 patients were divided into four groups: Group 1: treated with chitosan gel; Group 2: isosorbide dinitrate spray; Group 3: combination of isosorbide dinitrate spray and chitosan gel; Group 4: placebo., Results: Histological analyses showed a significant regeneration in all groups ( p < 0.001). On the final assessment of the ulcer, using the combination was found a wound closure percentage of 71 ± 30, 70 ± 27 using isosorbide dinitrate, 58 ± 30 with chitosan and 50 ± 16 with placebo. The number of patients who achieved complete ulcer closure was six using the combination, four with isosorbide dinitrate, three with chitosan and one with placebo. The progression in the healing process of the ulcer showed marked inmunohistochemical differences of Von Willebrand Factor, desmin, vascular endothelial growth factor-A and α-smooth muscle actin in all groups ( p < 0.001), but without notable differences between them., Conclusion: The combination was better than placebo to reduce the dimensions of the ulcer, accelerate healing and increase the number of patients who achieved complete closure of the ulcer, but the combination was not better than chitosan or isosorbide dinitrate used separately.

Scope: We performed a pooled analysis with trial sequential analysis (TSA) to evaluate the efficacy and safety of chitosan supplementation on serum lipids in humans., Methods and Results: Medline, EMBASE, and CENTRAL databases were queried. Impact was expressed as a weighted mean difference (WMD) and 95% confidence interval (CI). Sensitivity analysis was conducted using the leave-one-out method. Statistical heterogeneity, publication bias, TSA, and subgroup analyses were also assessed. Fourteen trials (21 treatment arms) encompassing 1108 participants were suitable for statistical pooling. Chitosan supplementation significantly improved the total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations in all patients. The WMDs were -0.20 mmol L -1 (95% CI, -0.35 to -0.05; p = 0.009) for TC, and -0.20 mol L -1 (95% CI, -0.26 to -0.15; p = 0.0001) for LDL-C, respectively. TSA demonstrated that the cumulative Z-curve crossed the trial sequential monitoring boundary for benefit providing conclusive evidence for the benefit of chitosan. However, no significant changes were seen with high-density lipoprotein cholesterol (HDL-C) and triglycerides. Our findings were robust after sensitivity analyses, and no serious adverse events were reported with chitosan intake., Conclusion: Supplementation with chitosan effectively reduces plasma concentrations of TC and LDL-C. Current evidence indicates daily chitosan supplementation as a candidate for therapeutic lipid management strategies., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Objective: To evaluate the feasibility and the safety of applying chitosan membrane (ChiMe) on the neurovascular bundles (NVBs) after nerve-sparing robot-assisted radical prostatectomy (NS-RARP). The secondary aim of the study was to report preliminary data and in particular potency recovery data., Patients and Methods: This was a single-centre, single-arm prospective study, enrolling all patients with localised prostate cancer scheduled for RARP with five-item version of the International Index of Erectile Function scores of >17, from July 2015 to September 2016. All patients underwent NS-RARP with ChiMe applied on the NVBs. The demographics, perioperative, postoperative and complications data were evaluated. Potency recovery data were evaluated in particular and any sign/symptom of local allergy/intolerance to the ChiMe was recorded and evaluated., Results: In all, 140 patients underwent NS-RARP with ChiMe applied on the NVBs. Applying the ChiMe was easy in almost all the cases, and did not compromise the safety of the procedure. None of the patients reported signs of intolerance/allergy attributable to the ChiMe and potency recovery data were encouraging., Conclusion: In our experience, ChiMe applied on the NVBs after NS-RARP was feasible and safe, without compromising the duration, difficulty or complication rate of the 'standard' procedure. No patients had signs of intolerance/allergy attributable to the ChiMe and potency recovery data were encouraging. A comparative cohort would have added value to the study. The present paper was performed before Conformité Européene (CE)-mark achievement., (© 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.)

Chitosan treatment results in significantly lower serum low density lipoprotein (LDL) cholesterol concentrations. To assess the working mechanisms of chitosan, we measured serum surrogate markers of cholesterol absorption (campesterol, sitosterol, cholestanol), synthesis (lathosterol, lanosterol, desmosterol), and degradation to bile acids (7α-hydroxy-cholesterol, 27-hydroxy-cholesterol), corrected for cholesterol concentration (R&#95;sterols). Over 12 weeks, 116 obese subjects (Body Mass Index, BMI 31.7, range 28.1-38.9 kg/m²) were studied under chitosan ( n = 61) and placebo treatments ( n = 55). The participants were briefly educated regarding improvement of nutrition quality and energy expenditure. Daily chitosan intake was 3200 mg. Serum LDL cholesterol concentration decreased significantly more ( p = 0.0252) under chitosan (-8.67 ± 18.18 mg/dL, 5.6%) than under placebo treatment (-1.00 ± 24.22 mg/dL, 0.9%). This reduction was not associated with the expected greater decreases in markers of cholesterol absorption under chitosan treatment. Also, increases in markers of cholesterol synthesis and bile acid synthesis under chitosan treatment were not any greater than under placebo treatment. In conclusion, a significant selective reduction of serum LDL cholesterol under chitosan treatment is neither associated with a reduction of serum surrogate markers of cholesterol absorption, nor with increases of markers for cholesterol and bile acid synthesis., Competing Interests: The authors declare that they have no conflict of interest. The founding sponsor played no role in the design of the study, in the collection, analyses, or interpretation of the data, in the writing of the manuscript, and in the decision to publish the results.

Background: Retinal neovascularization (NV) is the leading cause of blindness in the majority of ocular diseases. Several treatment approaches have been developed for retinal NV; of these methods, instillation of nanoparticles into the conjunctival sac has shown potential for retinal NV treatment because it does not cause physical damage and is easy to operate., Methods: In this study, honokiol-loaded chitosan/sulfobutylether-β-cyclodextrin nanoparticles (HKCS- NPs) were prepared for ophthalmic drug delivery systems. An inclusion complex of honokiol and sulfobutylether-β-cyclodextrin was used to incorporated insoluble honokiol into chitosan nanoparticles, which were prepared through ionotropic gelation., Results: HK-CS-NPs featured a spherical surface with a narrow size distribution of polydispersity index less than 0.250, a mean size range of 373-523 nm, a positive surface charge of +19.9 to +24.2 mV, and an entrapment efficiency of 84.92%. In vitro release studies showed an initial burst release phase and a sustained release phase of nanoparticles. Moreover, in vivo study showed that HK-CS-NPs exhibited good ocular tolerability and could improve ophthalmic bioavailability of honokiol. In particular, the maximum concentration of honokiol after administration of HK-CS-NPs was enhanced by 1.65 times compared with that after instillation of the honokiol suspension alone., Conclusion: This study proposes HK-CS-NPs as a potential ophthalmic delivery system., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Background: Chitosan is a popular dietary fiber often used to reduce dietary fat absorption to control weight and blood lipids. However, its effects on blood pressure (BP) have not been fully elucidated. We evaluated the effects of chitosan administration on systolic blood pressure (SBP) and diastolic blood pressure (DBP) through a pooled analysis of available randomized controlled trials (RCTs)., Materials and Methods: Electronic searches were conducted in Medline, Cochrane Library, Scopus, and EMBASE to identify relevant human placebo-control RCTs. Trials that reported BP changes from baseline to study endpoint in patients receiving treatment of chitosan were included for analysis. Weighted mean difference (WMD) and 95% CIs were pooled using fixed-effects or random-effects models. Statistical heterogeneity, prespecified subgroup, publication bias, sensitivity analysis, and meta-regression assessments were also tested., Results: Six hundred and seventeen participants from eight trials with 10 arms were included. Overall, chitosan administration did not significantly lower SBP (WMD: -1.41 mmHg, 95% CI: -3.29 to 0.47; P =0.14) and DBP (WMD: -0.61 mmHg, 95% CI: -1.75 to 0.52; P =0.29). However, our subgroup analyses indicated that chitosan consumption significantly reduced DBP in shorter-term (<12 weeks) and higher-dose (>2.4 g/day) arms. Funnel plots or Egger's tests analysis ( P =0.36 and 0.43 for SBP and DBP, respectively) demonstrated that there was no significant publication bias in this study., Conclusion: This meta-analysis indicates that chitosan consumption significantly decreases DBP at higher dosage and in shorter-term interventions, while chitosan has no significant effects on SBP. However, these results should be interpreted cautiously because of the limited eligible RCTs included in this meta-analysis; further large-scale, well-designed RCTs on this topic are urgently needed., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Chitosan is a natural polymer with applications in agriculture, which causes plasma membrane permeabilisation and induction of intracellular reactive oxygen species (ROS) in plants. Chitosan has been mostly applied in the phylloplane to control plant diseases and to enhance plant defences, but has also been considered for controlling root pests. However, the effect of chitosan on roots is virtually unknown. In this work, we show that chitosan interfered with auxin homeostasis in Arabidopsis roots, promoting a 2-3 fold accumulation of indole acetic acid (IAA). We observed chitosan dose-dependent alterations of auxin synthesis, transport and signalling in Arabidopsis roots. As a consequence, high doses of chitosan reduce WOX5 expression in the root apical meristem and arrest root growth. Chitosan also propitiates accumulation of salicylic (SA) and jasmonic (JA) acids in Arabidopsis roots by induction of genes involved in their biosynthesis and signalling. In addition, high-dose chitosan irrigation of tomato and barley plants also arrests root development. Tomato root apices treated with chitosan showed isodiametric cells respect to rectangular cells in the controls. We found that chitosan causes strong alterations in root cell morphology. Our results highlight the importance of considering chitosan dose during agronomical applications to the rhizosphere.

A novel type of macromolecular prodrug delivery system is reported in this research. The N-galactosylated-chitosan-5-fluorouracil acetic acid conjugate (GC-FUA) based nanoparticle delivery system was evaluated in vitro and in vivo. Biocompatibility of GC-FUA-NPs was screened by BSA adsorption test and hemolysis activity examination in vitro. Cytotoxicity and cellular uptake study in HepG2 and A549 cells demonstrated that compared to free 5-Fu, the GC-FUA-NPs play great function in killing cancer cells for the cell endocytosis mediated by asialoglycoprotein receptor (ASGPR), which overexpresses on the cell surface. Pharmacokinetics study further illustrated that the drug-loaded nanoparticles has a much longer half-time than free 5-Fu in blood circulation in Sprague-Dawley (SD) rats. Tissue distribution was investigated in Kunming mice, and the result showed that the GC-FUA-NPs have a long circulation effect. The obtained data suggested that GC-FUA-NP is a very promising drug delivery system for efficient treatment of hepatocellular carcinoma.

Anticancer immune responses depend on efficient presentation of tumor antigens and co-stimulatory signals provided by antigen-presenting cells (APCs). However, it is described that immature dendritic cells (DCs) and macrophages at the tumor site may have an immunosuppressive profile, which limits the activity of effector T cells and supports tumor progression. Therapeutic targeting of these innate immune cells, either aiming at their elimination or re-polarization towards an immunostimulatory profile, has been pointed as an attractive approach to control tumor progression. In the present work, we assessed the potential of Chitosan (Ch)/Poly(γ-glutamic acid) (γ-PGA) nanoparticles (NPs) to modulate macrophages and DCs inflammatory profile and to impair their ability to promote cancer cell invasion. Interestingly, Ch/γ-PGA NPs, prepared by co-acervation method, induced an immunostimulatory DCs phenotype, enhancing the expression of the co-stimulatory molecules CD86, CD40 and HLA-DR, and the secretion of the pro-inflammatory cytokines TNF-α, IL-12p40 and IL-6. Furthermore, Ch/γ-PGA NPs re-educated IL-10-stimulated macrophages towards a pro-inflammatory profile, decreasing the expression of CD163 and promoting the secretion of IL-12p40 and TNF-α. These alterations in the immune cells phenotype promoted CD4 + and CD8 + T cell activation/proliferation and partially inhibited APCs' ability to induce colorectal cancer cell invasion. Overall, our findings open new perspectives on the use of Ch/γ-PGA NPs as an immunomodulatory therapy for antigen-presenting cells reprogramming, providing a new tool for anticancer therapies., Statement of Significance: The immune system is responsible to detect and destroy abnormal cells preventing the development of cancer. However, the immunosuppressive tumor microenvironment can compromise the immune response favoring tumor progression. Thus, immune system modulation towards an immunostimulatory profile can improve anticancer therapies. This research focus on the development of chitosan/poly(γ-glutamic acid) nanoparticles (NPs) to modulate human antigen-presenting cells (APCs) phenotype and to counteract their pro-invasive capacity. Interestingly, Ch/γ-PGA NPs had a prominent effect in inducing macrophages and dendritic cells immunostimulatory phenotype, thus favoring T cell proliferation and inhibiting colorectal cancer cell invasion. We propose that their combination with other immunomodulatory drugs or conventional anticancer therapies can improve patients' outcome., (Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Recently, development of fluorescent nanoparticle-based probes for various bioimaging applications has attracted great attention. This work aims to develop a new type fluorescent nanoparticle conjugate and evaluate its cytotoxic effects on A549 and BEAS 2B cell lines. Throughout the study, ionically crosslinked chitosan nanoparticles (CNs) were conjugated with carboxylated 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY-COOH). The results of conjugates (BODIPY-CNs) were investigated with regard to their physic-chemical, optical, cytotoxic properties and cellular internalization. The morphology of BODIPY-CNs was found to be spherical in shape and quite uniform having average diameter of 70.25 ± 11.99 nm. Cytotoxicty studies indicated that although BODIPY-COOH itself was quite toxic on both A549- and BEAS 2B-treated cells, CNs increased the cell viability of both cell lines via conjugation to BODIPY-COOH fluorescent molecule up to 67% for A549 and 74% for BEAS 2B cells. These results may suggest a possible utilization of the new fluorescent nanoparticle-based probe for bioimaging in biology and medicine.

Based on our previous work on the PLGA nanoparticles modified with biotinylated chitosan (Bio-CS-PLGA NPs), we further studied the stability, toxicity, pharmacokinetics, and in vivo efficacy. The safety of NPs was studied through single-dose toxicity test in mice, and the result showed that NPs were well tolerated at the dose of 300 mg/kg. Compared with the free EPB group, the NPs group exhibited higher plasma drug concentration, longer half-life time. EPB-loaded NPs significantly inhibited the tumor growth compared to free EPB. All results suggested that Bio-CS-PLGA NPs were stable, safe, and showed a promising potential on targeted drug delivery.

Chitosan, produced from chitin, is one of the polymers with promising applications in various fields. However, despite diverse research studies conducted on its biocompatibility, its uses are still limited. The main reason is the degree of deacetylation (DOD), which represents the proportion of deacetylated units in the polymer and is directly correlated with its biocompatibility property. In this article, the in vivo biocompatibility of three chitosan-hydroxyapatite composite films composed of chitosan with different DOD values was investigated by traditional biological protocols and novel optical spectroscopic analyses. The DOD of the chitosan obtained from three different manufacturers was estimated and calculated by Raman spectroscopy, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. The chitosan with the higher DOD induced a higher incidence of inflammation in skin cells. The amino group density, biodegradability, and crystallinity of chitosan are the three possible factors that need to be considered when determining the biocompatibility of the films for in vivo application, as they led to complicated biological results, resulting in either better or worse inflammation even when using chitosan products with the same DOD. This basic study on the relationship between the DOD and inflammation is valuable for the development of further chitosan-based researches. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1637-1645, 2017., (© 2017 Wiley Periodicals, Inc.)

Purpose: This study was designed to evaluate the effect of chitosan-N-acetylcysteine (C-NAC) eye drops on tear film thickness (TFT) in patients with dry eye syndrome (DES)., Methods: This was a controlled, randomized, double-blind clinical investigation with patients assigned to 2 cohorts. In Cohort I, 21 patients were randomized to receive 1 instillation of C-NAC eye drops in 1 eye and placebo (normal saline solution) in the contralateral eye. In Cohort II, 17 patients were randomized to receive C-NAC eye drops once (QD) or twice (BID) daily for 5 days. TFT was assessed with a custom-built ultrahigh-resolution optical coherence tomography system., Results: In Cohort I, mean TFT increased from 3.9 ± 0.5 μm predose to 4.8 ± 1.1 μm 10 min postdose after treatment with C-NAC. The increase was significantly different from placebo over time (P < 0.0001) and remained stable until 24 h postdose. In Cohort II, TFT increased with QD and BID instillation, with no significant difference between regimens. In both groups, Ocular Surface Disease Index scores improved, fewer patients presented with corneal damage, and symptoms of ocular discomfort/conjunctival redness were reduced., Conclusions: A single instillation of C-NAC significantly increased mean TFT in patients with DES as early as 10 min after instillation and lasted for 24 h. The magnitude of the increase in TFT following a single instillation was comparable with that after instillation twice daily over 5 days. Corneal damage improved in >60% of patients. C-NAC could be a viable treatment option for DES.

Background: Patients on chronic hemodialysis often have acquired coagulopathy that can aggravate bleeding from puncture site after needle extraction. Chitosan-based pads have been reported to accelerate hemostasis even in the presence of coagulopathy. The aim of this study was to evaluate the hemostatic efficacy of the chitosan pads compared to gauze pads, applied for local hemostasis., Methods: A crossover study in a cohort of patients on hemodialysis with extended time to hemostasis after needle extraction. At the end of each dialysis, either gauze or chitosan pad was applied on both access points (arterial and venous). The type of pad was changed in the next dialysis all together 5 times in each patient (10 applications per patient for every pad)., Results: A total of 288 applications, 144 for each type of pad, were performed in 15 patients. The average time to hemostasis for the entire group was significantly shorter with the chitosan pads compared to the regular gauze pads ("arterial" point 3 vs. 18.5 min, p<0.001 "venous" access 2.8 vs. 13.2 min, p<0.001, respectively)., Conclusions: Chitosan pads significantly reduce time to hemostasis and should be considered for the treatment of accessible bleeds in patients with coagulopathy.

We tested the hypothesis that a combination of coagulant and ballast could be efficient for removal of positively buoyant harmful cyanobacteria in shallow tropical waterbodies, and will not promote the release of cyanotoxins. This laboratory study examined the efficacy of coagulants [polyaluminium chloride (PAC) and chitosan (made of shrimp shells)] alone, and combined with ballast (lanthanum modified bentonite, red soil or gravel) to remove the natural populations of cyanobacteria collected from a shallow eutrophic urban reservoir with alternating blooms of Cylindrospermopsis and Microcystis. PAC combined with ballast was effective in settling blooms dominated by Microcystis or Cylindrospermopsis. Contrary to our expectation, chitosan combined with ballast was only effective in settling Cylindrospermopsis-dominated blooms at low pH, whereas at pH≥8 no effective flocculation and settling could be evoked. Chitosan also had a detrimental effect on Cylindrospermopsis causing the release of saxitoxins. In contrast, no detrimental effect on Microcystis was observed and all coagulant-ballast treatments were effective in not only settling the Microcystis dominated bloom, but also lowering dissolved microcystin concentrations. Our data show that the best procedure for biomass reduction also depends on the dominant species., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Chronic wounds present a major challenge in modern medicine. Even under optimal conditions, the healing process may lead to scarring and fibrosis. The ability of mesenchymal stem cells (MSCs) to differentiate into other cell types makes these cells an attractive therapeutic tool for cell transplantation. Both tissue-engineered construct and MSC therapy are among the current wound healing procedures and potential care. Chitosan has been widely applied in tissue engineering because of its biocompatibility and biodegradability., Aim: The aim of the current work was to compare the efficiency of MSCs and chitosan dressing, alone or in combination treatment on wound healing., Methods: This study was conducted on 15 rabbits, which were randomly divided in 3 groups based on the type of treatment with MSCs, chitosan dressing and combination of both. A full-thickness skin defect was excised from the right and left side of the back of each animals. Defects on right sides were filled with treatments and left side defects were left as control. Evaluation of the therapeutic effectiveness was performed through a variety of clinical and microscopical evaluations and measurements of the process of wound healing on days 7, 14, 21, and 28. Histological evaluation of wound healing was classified by different scoring systems., Results: The data indicated that wounds treated with bone marrow derived MSC had enhanced cellularity and better epidermal regeneration. During the early stages of wound healing, the closure rate of bone marrow derived MSC-treated wounds were significantly higher than other treatments (P<0.05). Although the MSCs in the wound edges enhance the healing of the full-thickness wound, the healing process of chitosan treatment was slower than the control group., Conclusion: This study revealed advanced granulation tissue formation and epithelialization in wounds treated with MSCs, and may suggests this treatment as an effective applicant in wound healing process. Chitosan scaffold dressings, whether alone or in combination with MSCs, have worsened the wound healing as compared to the control group., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The nanotoxicity of Cd-containing quantum dots (QDs) for biomedical applications is very controversial and not completely understood. In this study, we evaluated the cytotoxicity of surface-biofunctionalized CdS QDs with chitosan directly synthesized via aqueous route at room temperature. These core-shell CdS-chitosan nanoconjugates showed different degrees of cytotoxic responses using MTT cell proliferation assay toward three human cell cultures, human osteosarcoma cell line (SAOS), non-Hodgkin's B cell lymphoma (Toledo), and human embryonic kidney cell line (HEK293T), under three exposure times (1, 3, and 5days) and three colloidal concentrations (10nM, 50nM, and 100nM). The results clearly demonstrated that the CdS QDs, regardless to the fact that they were coated with a biocompatible aminopolysaccharide shell, induced a severe dose- and time-dependent inhibition of cell viability. In addition, the HEK293T and SAOS cell lines showed much more sensitive response compared to Toledo, which indicated that the cytotoxicity was also cell-type dependent. The exceptional resistance of Toledo cells to toxic effects of CdS nanoconjugates even at severe test conditions was assigned to specific role of B-lineage cells of the immune defense system. Remarkably, no conclusive evidence of toxicity of CdS nanoconjugates was observed in vivo using intravenous injections of CdS nanoconjugates in BALB/c mouse animal models for 30days, but localized fluorescence was detected in ex-vivo liver tissue samples. Therefore, these results prove that there is no guarantee of "risk-free" use of CdS nanoconjugates for in vivo applications, even when functionalized with biopolymer ligands, as they can pose an excessive threat due to unpredicted and uncorrelated responses under in vitro and in vivo biological assays with highly toxic cadmium ions., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Chitosan nanoparticles (CS-NPs) and their Tween 80 modified counterparts (TmCS-NPs) are among the most commonly used brain-targeted vehicles. However, their potential developmental toxicity is poorly understood. In this study, zebrafish embryos are introduced as an in vivo platform. Both NPs showed a dose-dependent increase in developmental toxicity (decreased hatching rate, increased mortality and incidences of malformation). Neurobehavioral changes included decreased spontaneous movement in TmCS-NP treated embryos and hyperactive effect in CS-NP treated larvae. Both NPs remarkably inhibited axonal development of primary and secondary motor neurons, and affected the muscle structure. Overall, this study demonstrated that CS-NPs and TmCS-NPs could affect embryonic development, disrupt neurobehavior of zebrafish larvae and affect muscle and neuron development, suggesting more attention on biodegradable chitosan nanoparticles., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Uncontrolled hemorrhage leads to high death risk both in military and civilian trauma. Current hemostatic agents still have various limitations and side effects. In this study, natural diatom silica obtained from diatomite and diatom culture was purified and developed for hemorrhage control. To improve the biocompatibility and hemostatic performance of diatom silica, a series of chitosan-coated diatom (CS-diatom) was developed. The composition of CS-diatom prepared was optimized by in vitro hemocompatibility and blood coagulation evaluation for that prepared with 0.5%, 1%, 3%, and 5% chitosan. The results demonstrated that the CS-diatom prepared with 1% chitosan exhibited favorable biocompatibility (hemolysis ratio < 5%, no cytotoxicity to MEFs), great fluid absorbility (24.39 ± 1.53 times the weight of liquid), and desirable hemostasis effect (351 ± 14.73 s at 5 mg/mL, 248 ± 32.42s at 10 mg/mL). Further blood coagulation mechanism study indicated that CS-diatom could provide an ideal interface to induce erythrocyte absorption and aggregation, along with activating the intrinsic coagulation pathway and thus accelerated blood coagulation. Benefitting from the multiple hemostatic performances, CS-diatom showed the shortest clotting time (98.34 ± 26.54 s) and lowest blood loss (0.31 ± 0.11 g) in rat-tail amputation model compare to diatomite and diatom as well as gauze and commercial QuikClot zeolite. The results evidenced that the CS-diatom was a safe and effective hemostatic agent and provided a new understanding of nonsynthetic mesoporous materials for hemorrhage control.

In the present study, polyurethane materials were obtained from castor oil, polycaprolactone and isophorone diisocyanate by incorporating different concentrations of chitosan (0.5, 1.0 and 2.0% w/w) as an additive to improve the mechanical properties and the biological activity of polyurethanes. The polyurethanes were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, stress/strain fracture tests and swelling analysis, and the hydrophilic character of the surface was determined by contact angle trials. The objectives of the study were to evaluate the effect of the incorporation of chitosan on the changes of the physico-chemical and mechanical properties and the in vitro biological activity of the polyurethanes. It was found that the incorporation of chitosan enhances the ultimate tensile strength of the polyurethanes and does not affect the strain at fracture in polyurethanes with 5% w/w of polycaprolactone and concentrations of chitosan ranging from 0 to 2% w/w. In addition, PCL5-Q-PU formulations and their degradation products did not affect cell viability of L929 mouse fibroblast and 3T3, respectively. Polyurethane formulations showed antibacterial activities against Staphylococcus aureus and Escherichia coli bacteria. The results of this study have highlighted the potential biomedical application of this polyurethanes related to soft and cardiovascular tissues., (© The Author(s) 2016.)

Chitosan is a potential biopolymer for cell recognition and targeting; however, when those functions are based on cationic amine groups of chitosan, cell damage is a concern. This study presents water-based chitosan conjugated with thymine (CsT) through a mild and homogeneous conjugating reaction via amide bond without the use of organic and/or acidic solvents. The CsT displays water-solubility in a wide range of pH. A series of comparative gel retardation assays confirm the selective binding with poly(A), resulting in nanoparticles of 100 to 250 nm in size. PrestoBlue cell viability assay clarifies nontoxicity and reveals noncytotoxicity to normal colon cells but inhibition of colon cancer cells. This simple pathway for water-soluble chitosan-nucleic acid leads to synergistic effects of cell compatibility and DNA recognition.

The continuous rise of antimicrobial resistance and the dearth of new antibiotics in the clinical pipeline raise an urgent call for the development of potent antimicrobial agents. Cationic chitosan derivatives, N-(2-hydroxypropyl)-3-trimethylammonium chitosan chlorides (HTCC), have been widely studied as potent antibacterial agents. However, their systemic structure-activity relationship, activity toward drug-resistant bacteria and fungi, and mode of action are very rare. Moreover, toxicity and efficacy of these polymers under in vivo conditions are yet to be established. Herein, we investigated antibacterial and antifungal efficacies of the HTCC polymers against multidrug resistant bacteria including clinical isolates and pathogenic fungi, studied their mechanism of action, and evaluated cytotoxic and antimicrobial activities in vitro and in vivo. The polymers were found to be active against both bacteria and fungi (MIC = 125-250 μg/mL) and displayed rapid microbicidal kinetics, killing pathogens within 60-120 min. Moreover, the polymers were shown to target both bacterial and fungal cell membrane leading to membrane disruption and found to be effective in hindering bacterial resistance development. Importantly, very low toxicity toward human erythrocytes (HC 50 = >10000 μg/mL) and embryo kidney cells were observed for the cationic polymers in vitro. Further, no inflammation toward skin tissue was observed in vivo for the most active polymer even at 200 mg/kg when applied on the mice skin. In a murine model of superficial skin infection, the polymer showed significant reduction of methicillin-resistant Staphylococcus aureus (MRSA) burden (3.2 log MRSA reduction at 100 mg/kg) with no to minimal inflammation. Taken together, these selectively active polymers show promise to be used as potent antimicrobial agents in topical and other infections.

Purpose: Nasal galantamine hydrobromide (GH)/chitosan complex nanoparticles (CX-NP2) could have an improved therapeutic potential for managing Alzheimer's disease (AD). The current study aimed to investigate if the complexation reaction between GH and chitosan altered the pharmacological and toxicological profiles of the parent drug; GH., Methods: The nasal administration of CX-NP2 to male Wistar rats for 12 consecutive days was compared to negative control group, and oral and nasal GH solutions treated groups in 3 mg/kg daily GH dose. Brain acetylcholinesterase (AChE) protein level and activity were assessed. The in vivo toxicity of CX-NP2 was evaluated via monitoring the clinical signs throughout the study. Histopathological examination of brain sections was performed. The intracellular localization of CX-NP2 within brain neurons was investigated using transmission electron microscopy., Results: GH/chitosan complexation did not negatively alter the pharmacological efficiency of GH. Intriguingly, nasal CX-NP2 exhibited a significant decrease of AChE protein level and activity in rat brains compared to the oral and nasal GH solutions. No toxicity signs or histopathological manifestations were noticed. The nanoparticles were found intracellularly in the brain neurons., Conclusion: The pharmacological efficacy and in vivo safety of nasal CX-NP2 confirm their promising potential to contribute to the management of AD intranasally.