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Static analysis in FEA is one of the important analysis need to be done in preliminary stage of an engineering design process. It shows the static condition of a design with material used and load applied. This analysis also includes the constraints and other external features that applied during the actual application of the design. In this present study, a new material which is intermetallic Nickel Aluminides (Ni3Al) is used to study how it affects the automotive wheel hub at static condition. Intermetallic Nickel Aluminides have been used in automotive industry with its superior characteristics such as lightweight, good resistance in high temperature and corrosion, and high oxidation. The samples were heat treated for 400°C, 500°C and 600°C and the results were compared with the existing materials in order to review the performance.

Biopolymer-based composite hydrogels have attracted tremendous attention for tissue regeneration and antitumor applications. Since sodium alginate is a biopolymer, they offer excellent therapeutic options with long-term drug release and low side effects. To prepare multifunctional composite hydrogels with anticancer and tissue regeneration capabilities, sodium alginate (SA) and graphene oxide (GO) were covalently linked and crosslinked with tetraethyl orthosilicate (TEOS) by the solvothermal method. The structural and morphological results show that the hydrogels exhibit the desired functionality and porosity. The swelling of hydrogels in an aqueous and PBS medium was investigated. SGT-4 had the highest swelling in both aqueous and PBS media. Swelling and biodegradation of the hydrogel were inversely related. The drug release of SGT-4 was determined in different pH media (pH 6.4, 7.4, and 8.4) and the kinetics of drug release was determined according to the Higuchi model (R2 = 0.93587). Antibacterial activities were evaluated against severe infectious agents. Uppsala (U87) and osteoblast (MC3T3-E1) cell lines were used to determine the anticancer and biocompatibility of the composite hydrogels, respectively. These results suggest that the composite hydrogels could be used as potential biomaterials for tissue regeneration and antitumor applications.

Carbohydrate polymers are biological macromolecules that have sparked a lot of interest in wound healing due to their outstanding antibacterial properties and sustained drug release. Arabinoxylan (ARX), Chitosan (CS), and reduced graphene oxide (rGO) sheets were combined and crosslinked using tetraethyl orthosilicate (TEOS) as a crosslinker to fabricate composite hydrogels and assess their potential in wound dressing for skin wound healing. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and biological assays were used to evaluate the composite hydrogels. FTIR validated the effective fabrication of the composite hydrogels. The rough morphologies of the composite hydrogels were revealed by SEM and AFM (as evident from the Ra values). ATC-4 was discovered to have the roughest surface. TEM revealed strong homogeneous anchoring of the rGO to the polymer matrix. However, with higher amount of rGO agglomeration was detected. The % swelling at various pHs (1−13) revealed that the hydrogels were pH-sensitive. The controlled release profile for the antibacterial drug (Silver sulfadiazine) evaluated at various pH values (4.5, 6.8, and 7.4) in PBS solution and 37 °C using the Franz diffusion method revealed maximal drug release at pH 7.4 and 37 °C. The antibacterial efficacy of the composite hydrogels against pathogens that cause serious skin diseases varied. The MC3T3-E1 cell adhered, proliferated, and differentiated well on the composite hydrogels. MC3T3-E1 cell also illustrated excellent viability (91%) and proper cylindrical morphologies on the composite hydrogels. Hence, the composite hydrogels based on ARX, CS, and rGO are promising biomaterials for treating and caring for skin wounds.

As one of the world’s most abundant biomass, lignocellulosic materials such as rice husk (RH) has been recognized for its various potential usages. Electrospun nanofibrous mats have been fabri-cated from various natural and synthetic polymers and offers a wide range of promising criteria suitable for wound dressing applications. Natural polymers have grabbed considerable attention due to their desirable properties. Therefore, the application of cellulose-derived materials from agricultural waste becomes crucial as a green alternative to produce electrospun wound dressing with excellent wettability, porosity and tunability to promote wound healing at relatively low costs. Interestingly, a specific study on the utilization of cellulose extracted from RH to produce electrospun nanofibrous mat remains unreported. Therefore, this work aimed to investigate the feasibility of using RH as a source of raw materials to create nanofibrous mats for use as pro-spective wound dressing materials. In this paper, cellulose extracted from RH will be converted into its derivate, cellulose acetate (CA) and electrospun. The nanofiber will be characterized by Scanning Electron Microscope (SEM), Attenuated Total Reflectance- Fourier transform spectros-copy (ATR-FTIR), water contact angle to evaluate the main properties of the electrospun nano-fibrous mat.

Vitamin D deficiency is now a global health problem; despite several drug delivery systems for carrying vitamin D due to low bioavailability and loss bioactivity. Developing a new drug delivery system to deliver vitamin D3 is a strong incentive in the current study. Hence, an implantable drug delivery system (IDDS) was developed from the electrospun cellulose acetate (CA) and e-polycaprolactone (PCL) nanofibrous membrane, in which the core of implants consists of vitamin D3-loaded CA nanofiber (CAVD) and enclosed in a thin layer of the PCL membrane (CAVD/PCL). CA nanofibrous mat loaded with vitamin D3 at the concentrations of 6, 12, and 20% (w/w) of vitamin D3 were produced using electrospinning. The smooth and bead-free fibers with diameters ranged from 324 to 428 nm were obtained. The fiber diameters increased with an increase in vitamin D3 content. The controlled drug release profile was observed over 30-days, which fit with the zero-order model (R2 > 0.96) in the first stage. The mechanical properties of IDDS were improved. Young's modulus and tensile strength of CAVD/PCL (dry) were161 ± 14 and 13.07 ± 2.5 MPa, respectively. CA and PCL nanofibers are non-cytotoxic based on the results of the in-vitro cytotoxicity studies. This study can further broaden in-vivo study and provide a reference for developing a new IDDS to carry vitamin D3 in the future.

The importance of bone scaffolds has increased many folds in the last few years; however, during bone implantation, bacterial infections compromise the implantation and tissue regeneration. This work is focused on this issue while not compromising on the properties of a scaffold for bone regeneration. Biocomposite scaffolds (BS) were fabricated via the freeze-drying technique. The samples were characterized for structural changes, surface morphology, porosity, and mechanical properties through spectroscopic (Fourier transform-infrared [FT-IR]), microscopic (scanning electron microscope [SEM]), X-ray (powder X-ray diffraction and energy-dispersive X-ray), and other analytical (Brunauer-Emmett-Teller, universal testing machine Instron) techniques. Antibacterial, cellular, and hemocompatibility assays were performed using standard protocols. FT-IR confirmed the interactions of all the components. SEM illustrated porous and interconnected porous morphology. The percentage porosity was in the range of 49.75%-67.28%, and the pore size was 215.65-470.87 µm. The pore size was perfect for cellular penetration. Thus, cells showed significant proliferation onto these scaffolds. X-ray studies confirmed the presence of nanohydroxyapatite and graphene oxide (GO). The cell viability was 85%-98% (BS1-BS3), which shows no significant toxicity of the biocomposite. Furthermore, the biocomposites exhibited better antibacterial activity, no effect on the blood clotting (normal in vitro blood clotting), and less than 5% hemolysis. The ultimate compression strength for the biocomposites increased from 4.05 to 7.94 with an increase in the GO content. These exciting results revealed that this material has the potential for possible application in bone tissue engineering.

In biomedical application, the fabrication of biodegradable scaffolds using 3D printing technology has vastly increased to accommodate the complex structure of substitutes. In this study, PLLA and ...

A new potential biomimetic polymeric 3D scaffold is fabricated using collagen entrapment and 3D printed polylactic acid scaffold. The modified scaffold was characterized by compressive modulus, degree of swelling, water contact angle (WCA), and Fourier Transform Infrared Spectroscopy (FTIR). The findings show that sample PLA/col40 with 40 s entrapment duration is the optimum composition that meets the requirement for artificial bone tissue replacement. In vitro biomineralization using simulated body fluid (SBF) demonstrates that the PLA/collagen 3D scaffold is able to promote the growth of hydroxyapatite (HA) after 7 days which will subsequently improve the osteoconductive and osteoinductive properties of the 3D scaffold. The overall results suggest the potential of the 3D PLA/collagen scaffold as a prospective material for bone tissue engineering applications.

The number of deaths has been increased due to COVID-19 infections and uncertain neurological complications associated with the central nervous system. Post-infections and neurological manifestations in neuronal tissues caused by COVID-19 are still unknown and there is a need to explore how brainstorming promoted congenital impairment, dementia, and Alzheimer’s disease. SARS-CoV-2 neuro-invasion studies in vivo are still rare, despite the fact that other beta-coronaviruses have shown similar properties. Neural (olfactory or vagal) and hematogenous (crossing the blood–brain barrier) pathways have been hypothesized in light of new evidence showing the existence of SARS-CoV-2 host cell entry receptors into the specific components of human nerve and vascular tissue. Spike proteins are the primary key and structural component of the COVID-19 that promotes the infection into brain cells. Neurological manifestations and serious neurodegeneration occur through the binding of spike proteins to ACE2 receptor. The emerging evidence reported that, due to the high rate in the immediate wake of viral infection, the olfactory bulb, thalamus, and brain stem are intensely infected through a trans-synaptic transfer of the virus. It also instructs the release of chemokines, cytokines, and inflammatory signals immensely to the blood–brain barrier and infects the astrocytes, which causes neuroinflammation and neuron death; and this induction of excessive inflammation and immune response developed in more neurodegeneration complications. The present review revealed the pathophysiological effects, molecular, and cellular mechanisms of possible entry routes into the brain, pathogenicity of autoantibodies and emerging immunotherapies against COVID-19.

Globally, people suffering from bone disorders are steadily increasing and bone tissue engineering is an advanced approach to treating fractured and defected bone tissues. In this study, we have prepared polymeric nanocomposite by free-radical polymerization from sodium alginate, hydroxyapatite, and silica with different GO amounts. The porous scaffolds were fabricated using the freeze drying technique. The structural, morphological, mechanical, and wetting investigation was conducted by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, universal tensile machine, and water contact angle characterization techniques. The swelling, biodegradation, and water retention were also studied. The biological studies were performed (cell viability, cell adherence, proliferation, and mineralization) against osteoblast cell lines. Scaffolds have exhibited different pore morphology SAG-1 (pore size = 414.61 ± 56 μm and porosity = 81.45 ± 2.17 %) and SAG-4 (pore size = 195.97 ± 82 μm and porosity = 53.82 ± 2.45 %). They have different mechanical behavior as SAG-1 has the least compression strength and compression modulus 2.14 ± 2.35 and 16.51 ± 1.27 MPa. However, SAG-4 has maximum compression strength and compression modulus 13.67 ± 2.63 and 96.16 ± 1.97 MPa with wetting behavior 80.70° and 58.70°, respectively. Similarly, SAG-1 exhibited the least and SAG-4 presented maximum apatite mineral formation, cell adherence, cell viability, and cell proliferation against mouse pre-osteoblast cell lines. The increased GO amount provides different multifunctional materials with different characteristics. Hence, the fabricated scaffolds could be potential scaffold materials to treat and regenerate fracture bone tissues in bone tissue engineering.

Polymeric materials have been essential biomaterials to develop hydrogels as wound dressings for sustained drug delivery and chronic wound healing. The microenvironment for wound healing is created by biocompatibility, bioactivity, and physicochemical behavior. Moreover, a bacterial infection often causes the healing process. The bacterial cellulose (BC) was functionalized using graphene oxide (GO) by hydrothermal method to have bacterial cellulose-functionalized-Graphene oxide (BC

The growing demand for nanocellulose materials synthesized from renewable sources has increased over the years (Kargarzadeh et al. 2012). Nanocelluloses are abundant, economical, biodegradable, and...

Arabinoxylan (AX) is a natural biological macromolecule with several potential biomedical applications. In this research, AX, nano-hydroxyapatite (n-HAp) and titanium dioxide (TiO2) based polymeric nanocomposite scaffolds were fabricated by the freeze-drying method. The physicochemical characterizations of these polymeric nanocomposite scaffolds were performed for surface morphology, porosity, swelling, biodegradability, mechanical, and biological properties. The scaffolds exhibited good porosity and rough surface morphology, which were efficiently controlled by TiO2 concentrations. MC3T3-E1 cells were employed to conduct the biocompatibility of these scaffolds. Scaffolds showed unique biocompatibility in vitro and was favorable for cell attachment and growth. PNS3 proved more biocompatible, showed interconnected porosity and substantial mechanical strength compared to PNS1, PNS2 and PNS4. Furthermore, it has also showed more affinity to cells and cell growth. The results illustrated that the bioactive nanocomposite scaffold has the potential to find applications in the tissue engineering field.

This work reports the fabrication and characterizations of porous scaffold made up of polylactic acid (PLA) with the inclusion of pectin (1, 3, 5, 7, 9, 11 wt%) for potential tissue engineering material. The composite scaffold was prepared using a facile method of freeze extraction. Based on the physical evaluations, the scaffold was suggested to be optimum at 5 wt% of pectin loading. Water contact angle of the scaffold was significantly reduced to 46.5o with the inclusion of 5 wt% of pectin. Morphological and topographic of the PLA scaffold revealed that the pectin induced more porous structure and its surface became rougher which was suitable for cell attachment and proliferation. In vitro studies of the PLA/pectin composite scaffold using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidelt (MTT) assay revealed good biocompatibility whereas Live-Dead kit assay resulted in 91% cell viability after 7 days of incubation.

The excellent biocompatible and osteogenesis characteristics of porous scaffolds play a vital role in bone regeneration.

Tissue engineering is a cutting-edge approach for using advanced biomaterials to treat defective bone to get desired clinical results. In bone tissue engineering, the scaffolds must have the desired physicochemical and biomechanical natural properties in order to regenerate complicated defective bone. For the first time, polymeric nanocomposite material was developed using cellulose and co-dispersed nanosystem (Fe

Wound healing is an important physiological process involving a series of cellular and molecular developments. A multifunctional hydrogel that prevents infection and promotes wound healing has great significance for wound healing applications in biomedical engineering. We have functionalized arabinoxylan and graphene oxide (GO) using the hydrothermal method, through cross-linking GO-arabinoxylan and polyvinyl alcohol (PVA) with tetraethyl orthosilicate (TEOS) to get multifunctional composite hydrogels. These composite hydrogels were characterized by FTIR, SEM, water contact angle, and mechanical testing to determine structural, morphological, wetting, and mechanical behavior, respectively. Swelling and biodegradation were also conducted in different media. The enhanced antibacterial activities were observed against different bacterial strains (

Several significant advancements in the field of bone regenerative medicine have been made in recent years. However, therapeutic options, such as bone grafts, have several drawbacks. There is a need to develop an adequate bone substitute. As a result, significant bone defects/injuries pose a severe challenge for orthopaedic and reconstructive bone tissue. We synthesized polymeric composite material from arabinoxylan (ARX), β-glucan (BG), nano-hydroxyapatite (nHAp), graphene oxide (GO), acrylic acid (AAc) through free radical polymerization and porous scaffold fabricated using the freeze-drying technique. These fabricated porous scaffolds were then coated with chitosan solution to enhance their biological activities. The complex structure of BG, nHAp, GO was studied through various characterization and biological assays. The structural, morphological, wetting and mechanical analyses were determined using FT-IR, XRD, XPS, SEM/EXD, water contact angle and UTM. The swelling (aqueous and PBS media) and degradation (PBS media) observed their behavior in contact with body fluid. The biological activities were conducted against mouse pre-osteoblast cell lines. The result found that BGH3 has desirable morphological, structural with optimum swelling, degradation, and mechanical behavior. It was also found to be cytocompatible against MC3T3-E1 cell lines. The obtained results confirmed that the fabricated polymeric scaffolds would be a potential bone substitute to regenerate defective bone with different loading bearing applications for bone tissue engineering.

Background The primary role of bone tissue engineering is to reconcile the damaged bones and facilitate the speedy recovery of the injured bones. Whilst, some of the investigated metallic implants suffer from stress-shielding, palpability, biocompatibility, etc. Consequently, the biodegradable scaffolds fabricated from polymers have gathered much attention from researchers and thus helped the tissue engineering sector by providing many alternative materials whose functionality is similar to that of natural bones. Material and methods Herein, we present the fabrication and testing of a novel composite, magnesium (Mg)-doped hydroxyapatite (HAp) glazed onto polylactic acid (PLA) scaffolds where polyvinyl alcohol (PVA) used as a binder. For the composite formation, Creality Ender-3 pro High Precision 3D Printer with Shape tool 3D Technology on an FSD machine operated by Catia design software was employed. The composite has been characterized for the crystallinity (XRD), surface functionality (FTIR), morphology (FESEM), biocompatibility (hemolytic and protein absorption), and mechanical properties (stress-strain and maximum compressive strength). Results The powdered XRD analysis confirmed the semicrystalline nature and intact structure of HAp even after doping with Mg, while FTIR studies for the successful formation of Mg-HAp/PVA@PLA composite. The FESEM provided analysis indicated for the 3D porous architecture and well-defined morphology to efficiently transport the nutrients, and the biocompatibility studies are supporting that the composite is blood compatible with the surface being suitable enough for the protein absorption. Finally, the composite's antibacterial activity (against Staphylococcus aureus and Escherichia coli) and the test of mechanical properties supported for the enhanced inhibition of active growth of microorganisms and maximum compressive strength, respectively. Conclusion Based on the research outcomes of biocompatibility, antibacterial activity, and mechanical resistance, the fabricated Mg-HAp/PVA@PLA composite suits well as a promising biomaterial platform for orthopedic applications by functioning towards the open reduction internal fixation of bone fractures and internal repairs.

Immobilized polyaniline on glass plates (PANI/glass) and its powder form were compared for the adsorption of methyl orange (MO) dye from aqueous solutions. The effects of operational parameters such as pH, sorbent dosage, initial concentration, contact time, aeration rate and the thermodynamics of the uptake of MO had been exhaustively evaluated. The maximum adsorption capacity (qmax) for PANI/glass and PANI powder was 93 and 147 mg g−1, respectively. In addition, pseudo-second order model was the best fitted kinetic model for both systems, suggesting that the rate-limiting step may be chemisorptions. The obtained negative values of free energy and enthalpy indicated the adsorption process was spontaneous and exothermic. In contrast to PANI powder, PANI/glass yielded negative entropy. Photocatalytic regeneration of used PANI/glass was found to be highly effective where the desorbed MO was completely mineralized. This study showed that immobilized PANI offered the unique advantage of convenient use and reuse over an extended period of applications. Keywords: Immobilized polyaniline, Methyl orange, Reusable, Photocatalytic regeneration, Wastewater treatment

Purpose Over the years, electrical stimulation in drug delivery system holds particular interest in producing spatially and temporally controlled release mechanism. These systems helped in localized doses drugs to be administrated and response efficiently at target site to achieve excellent healing effect in control microenvironment. Extensive research is needed in order to develop versatile electroactive biomaterials in the field of therapeutics applications. This paper aims to discuss this issue. Design/methodology/approach This work reports the development of polycaprolactone (PCL) electrospun coated with pectin/polyaniline (PANi) composite, which has been characterized and whose drug delivery application is ascertained. The composite has been characterized on its mechanical conductivity and wettability properties to evaluate best formulation. The analysis on morphological properties using scanning electron microscope (SEM) confirmed the formation of the dual-layer electro-responsive composite. Findings Among different formulations studied, the pectin/PANi composition (12 percent/3 percent) was found to be an optimized composition with ultimate tensile strength of 55.48±0.65 MPa and modulus strength of 63.30±0.43 MPa with 2.41×10–3 Scm−1 electrical percolation. The hydrophobic PCL electrospun reduced as coating material was introduced on top with optimum of 85.3 percent degree of swelling and water contact angle at 39.17±0.67°. SEM micrograph revealed strong interaction between dual-layer structures with interconnected porous of uniform fibers. Originality/value Overall, these data present a multiangle initial characterization of this novel dual-layer electro-responsive composite for applications in drug delivery. However, additional analysis should be performed in order to provide a clear verification as drug delivery scaffold.

This work reports the inclusion of crocin (an active agent of saffron) into bacterial nanocellulose (BNC) membrane for transdermal drug delivery. The BNC showed good uptake of the crocin based on the swelling studies and vibrational peaks of the FTIR spectra. Surface morphology of the crocin loaded BNC showed that the fibrous nano feature was still intact with no fiber damages. The crocin release via direct dissolution showed typical burst release. Franz diffusion test revealed stable and prolong drug permeation. Partition coefficient of the BNC-crocin via mice epidermal skin diffusion was found to be 2.44×10−4 cm−2 min−1 with the average mass flux of 0.53 cm−2 min−1. This facile method of utilizing BNC for the carrier of crocin can be useful for administrating other water soluble active compound. Thus BNC opens up choices for the delivery of crocin for medicinal purposes.

Bacterial cellulose (BC) is an innovative polymeric nanofibre, which meets the demands of rapidly advancing industries, such as biomedical engineering, food packaging, pulp and paper and electrical appliance engineering. The versatility of bacterial cellulose is largely due to its unique properties, such as high crystallinity, high thermal stability, high water absorption capacity, hydrophilicity, good mechanical strength, biodegradability, high biocompatibility and high porosity, making it well-suited for applications in various fields. In recent years, advances for enhancing the applicability of BC through modification and its inclusion into composites have been in focus. Unfortunately, despite the multiple advantages it offers, the production cost of BC is too high, thus reducing/limiting its commercial attractiveness and industrial scale production. This paper is an overview of the current research trends for developing cheaper BC production pathways and of recent advances performed so far with the prospect of enhancing its potential application in biomedical engineering.

The transdermal patch is polymeric-based patches containing a dispersed bioactive ingredient that deliver therapeutic agents at a constant rate through the human skin surface. In this study, the dual layer PVA patch was prepared using a combination of freezing-thawing (F-T) and electrospinning techniques to study the effect of F-T cycles on morphology structure and swelling ratio of the fabricated patch. The effect of F-T cycles on swelling ability as well as the morphological study of the patch was employed and characterized using Scanning Electron Microscopy (SEM) and immersion of dual layer PVA patch for 24 hours in distilled water was calculated. Morphological structure of dual layer PVA patch has proved the correlation between the PVA cryogel and PVA electrospun nanofiber membrane. The results revealed that the dual layer PVA patch was successfully fabricated as the under layer PVA electrospun nanofiber membrane does not fully dissolve throughout the F-T process. Furthermore, in this study, it is shown that increasing of F-T cycles has decreased the swelling ability of the dual layer PVA patch. It also found that the presence of PVA electrospun nanofiber has also affected the swelling ability of the dual layer PVA patch due to the high surface ratio of the electrospun nanofiber membrane. The highest percentage of swelling ratio was found approaching 66% for dual layer PVA with 3 cycles (2L-3C), as for dual layer PVA with 5 cycles (2L-5C) the percentage found significantly lower (33%). The improvement of dual layer PVA patch can be utilized for drug release assessment and also could be good potential for transdermal drug delivery.

A medication’s approximate release profile should be sustained in order to generate the desired therapeutic effect. The drug’s release site, duration, and rate must all be adjusted to the drug’s therapeutic aim. However, when designing drug delivery systems, this may be a considerable hurdle. Electrospinning is a promising method of creating a nanofibrous membrane since it enables drugs to be placed in the nanofiber composite and released over time. Nanofiber composites designed through electrospinning for drug release purposes are commonly constructed of simple structures. This nanofiber composite produces matrices with nanoscale fiber structure, large surface area to volume ratio, and a high porosity with small pore size. The nanofiber composite’s large surface area to volume ratio can aid with cell binding and multiplication, drug loading, and mass transfer processes. The nanofiber composite acts as a container for drugs that can be customized to a wide range of drug release kinetics. Drugs may be electrospun after being dissolved or dispersed in the polymer solution, or they can be physically or chemically bound to the nanofiber surface. The composition and internal structure of the nanofibers are crucial for medicine release patterns.

Silver nanoparticles (AgNPs) are commonly used in numerous consumer products, including textiles, cosmetics, and health care items. The widespread usage of AgNPs results in their unavoidable discharge into the ecosystem, which pollutes the aquatic, groundwater, sediments, and marine environments. These nanoparticles (NPs) activate the production of free radicals reactive species in aquatic organisms that interrupt the functions of DNA, cause mitochondrial dysfunction, and increase lipid peroxidation, which terminates the development and reproduction both in vivo and in vitro. The life present in the aquatic ecosystem is becoming threatened due to the release and exploitation of AgNPs. Managing the aquatic ecosystem from the AgNP effects in the near future is highly recommended. In this review, we discussed the background of AgNPs, their discharge, and uptake by aquatic organisms, the mechanism of toxicity, different pathways of cytotoxicity, and bioaccumulation, particularly in aquatic organisms. We have also discussed the antimicrobial activities of AgNPs along with acute and chronic toxicity in aquatic groups of organisms.

Bacterial cellulose (BC) has gained research attention in materials science and biomedicine due to its fascinating properties. BCs' fiber collapse phenomenon (inability to reabsorb water after dehydration) is one of the drawbacks that limit its potentials. To overcome this, a catalyst-free thermal crosslinking reaction was employed to modify the BC using citric acid (CA) without compromising the biocompatibility. Properties evaluation of the modified BC (MBC) by FTIR, XRD, SEM/EDX, TGA, and Tensile analysis confirmed the fiber crosslinking and improvement of some properties that could be advantageous for various applications. The modified nanofiber seems to maintain its inherent crystallinity and thermal stability with an increased water absorption/swelling and tensile modulus. The resulting MBC reported here can be relevant for wound dressings and tissue scaffolding.

Bone tissue engineering is an advanced field for treatment of fractured bones to restore/regulate biological functions. Biopolymeric/bioceramic-based hybrid nanocomposite scaffolds are potential biomaterials for bone tissue because of biodegradable and biocompatible characteristics. We report synthesis of nanocomposite based on acrylic acid (AAc)/guar gum (GG), nano-hydroxyapatite (HAp NPs), titanium nanoparticles (TiO2 NPs), and optimum graphene oxide (GO) amount via free radical polymerization method. Porous scaffolds were fabricated through freeze-drying technique and coated with silver sulphadiazine. Different techniques were used to investigate functional group, crystal structural properties, morphology/elemental properties, porosity, and mechanical properties of fabricated scaffolds. Results show that increasing amount of TiO2 in combination with optimized GO has improved physicochemical and microstructural properties, mechanical properties (compressive strength (2.96 to 13.31 MPa) and Young’s modulus (39.56 to 300.81 MPa)), and porous properties (pore size (256.11 to 107.42 μm) and porosity (79.97 to 44.32%)). After 150 min, silver sulfadiazine release was found to be ~94.1%. In vitro assay of scaffolds also exhibited promising results against mouse pre-osteoblast (MC3T3-E1) cell lines. Hence, these fabricated scaffolds would be potential biomaterials for bone tissue engineering in biomedical engineering.

Vitamin D deficiency is now a global health problem; despite several drug delivery systems for carrying vitamin D due to low bioavailability and loss bioactivity. Developing a new drug delivery system to deliver vitamin D

Stingless bee honey has a distinctive flavor and sour taste compared to Apis mellifera honey. Currently, interest in farming stingless bees is growing among rural residents to meet the high demand for raw honey and honey-based products. Several studies on stingless bee honey have revealed various therapeutic properties for wound healing applications. These include antioxidant, antibacterial, anti-inflammatory, and moisturizing properties related to wound healing. The development of stingless bee honey for wound healing applications, such as incorporation into hydrogels, has attracted researchers worldwide. As a result, the effectiveness of stingless bee honey against wound infections can be improved in the future to optimize healing rates. This paper reviewed the physicochemical and therapeutic properties of stingless bee honey and its efficacy in treating wound infection, as well as the incorporation of stingless bee honey into hydrogels for optimized wound dressing.

Wound dressing have experienced continuous improvement and changes since ancient time. Electrospinning of polymeric nanofibers have captured the interest of researchers due to its simplicity and cost effective technique that able to produce wound dressing membrane that meet the requirement as ideal wound dressing and drug delivery carrier. In this work, polyvinyl alcohol (PVA) and poly (lactic acid) (PLA) were chosen polymer to produce wound dressing membrane through electrospinning and coating method. PVA was electrospun and then coated with PLA. Preliminary study had been conducted between 1, 4 and 8% concentration for the selection of optimum PLA coating concentration. PLA has been proposed for the use of coating materials at 4%, the coated nanofiber membrane started to exhibit high Ultimate Tensile Strength at 1022.5 ± 9.28 MPa, highest degree of swelling (1850 ± 3.7 %) and optimum water contact angle (60.9 ± 11.46˚). The aim of this study was to investigate the morphological properties of PVA/PLA wound dressing membrane. Based on the results from Atomic Force Microscope, PVA nanofiber coated with 4% PLA exhibit the highest value of Rq which is 0.47 ± 0.19 μm compared to neat PVA nanofibers membrane. Field Emission Scanning Electron Microscope (FE-SEM) image revealed that PVA nanofiber coated with 4% PLA shows porous fiber-like morphology and well incorporated with each other without any gap formed between them. This report clearly suggestive of the fact that synthetic biodegradable polymers such as PLA can be exploited for the synergistic combination with PVA nanofiber for wound dressing application.

This review focuses on the potential of polyvinylidene fluoride (PVDF) as tissue scaffolding materials. PVDF is defined in terms of the synthesis mechanisms and the method of the β phase formation process. General properties are fundamentally discussed in terms of their wettability and electroactive characteristics, which play an essential role in modifying other potential materials for tissue-based applications. The latest technologies for the replacement of artificial tissue scaffolds are evaluated, and the applications of PVDF-based scaffolds are discussed.

The excellent biocompatible and osteogenesis characteristics of porous scaffolds play a vital role in bone regeneration. In this study, we have synthesized polymeric hybrid nanocomposites

Advancement and innovation in bone regeneration, specifically polymeric composite scaffolds, are of high significance for the treatment of bone defects. Xyloglucan (XG) is a polysaccharide biopolymer having a wide variety of regenerative tissue therapeutic applications due to its biocompatibility, in-vitro degradation and cytocompatibility. Current research is focused on the fabrication of polymeric bioactive scaffolds by freeze drying method for nanocomposite materials. The nanocomposite materials have been synthesized from free radical polymerization using n-SiO2 and n-HAp XG and Methacrylic acid (MAAc). Functional group analysis, crystallinity and surface morphology were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) techniques, respectively. These bioactive polymeric scaffolds presented interconnected and well-organized porous morphology, controlled precisely by substantial ratios of n-SiO2. The swelling analysis was also performed in different media at varying temperatures (27, 37 and 47 °C) and the mechanical behavior of the dried scaffolds is also investigated. Antibacterial activities of these scaffolds were conducted against pathogenic gram-positive and gram-negative bacteria. Besides, the biological behavior of these scaffolds was evaluated by the Neutral Red dye assay against the MC3T3-E1 cell line. The scaffolds showed interesting properties for bone tissue engineering, including porosity with substantial mechanical strength, biodegradability, biocompatibility and cytocompatibility behavior. The reported polymeric bioactive scaffolds can be aspirant biomaterials for bone tissue engineering to regenerate defecated bone.

It is a challenging task to develop active biomacromolecular wound dressing materials that are biocompatible and possesses antibacterial properties against the bacterial strains that cause severe skin disease. This work is focused on the preparation of a biocompatible and degradable hydrogel for wound dressing application using arabinoxylan (ARX) and guar gum (GG) natural polymers. Fourier transform infrared spectroscopy (FT-IR) confirmed that both ARX and GG interacted well with each other, and their interactions further increased with the addition of crosslinker tetraethyl orthosilicate. Scanning electron microscope (SEM) micrographs showed uniform porous morphologies of the hydrogels. The porous morphologies and uniform interconnected pores are attributed to the increased crosslinking of the hydrogel. Elastic modulus, tensile strength, and fracture strain of the hydrogels significantly improved (from ATG-1 to ATG-4) with crosslinking. Degradability tests showed that hydrogels lost maximum weight in 7 days. All the samples showed variation in swelling with pH. Maximum swelling was observed at pH 7. The hydrogel samples showed good antibacterial activity against Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) in PBS, good drug release profile (92% drug release), and nontoxic cellular behavior. The cells not only retained their cylindrical morphologies onto the hydrogel but were also performing their normal activities. It is, therefore, believed that as-developed hydrogel could be a potential material for wound dressing application.

Immobilization of chlorhexidine (CHX) coating on medical devices by utilizing a polydopamine (PDA) film as an intermediate crosslinker, demonstrates a promising value in retarding bacterial growth. However, its long-term antibacterial effect and coating stability are unknown where those features are crucial to sustain long-term application of medical devices. In this study, both properties were evaluated on the CHX-PDA coated SS316L. Greater surface roughness and coating thickness were observed on the SS-PDA-CHX20 compared to the SS-PDA. The CHX adsorption on the PDA film was increased as the CHX concentration increased. The 28 days of ageing process presented gradual coating degradation on the SS-PDA-CHX20 and SS-PDACHX30, releasing the CHX compound. The higher CHX concentration also displayed larger CHX aggregates and higher inhibition zones against E. coli and S. aureus, up to 72 h, indicating the substantivity of antibacterial effect. These properties hold a great potential in preventing bacterial growth on medical devices.

This work reports the surface modification of 3D printed PLA scaffold with chitosan and its hydroxyapatite (HA) forming capability. PLA scaffold was fabricated using a desktop 3D printer followed by the inclusion of chitosan on the surface via surface entrapment. Confocal laser scanning microscopy (CLSM) images showed existence of chitosan entrapment with depth of 24 μm. Immersion of the modified PLA scaffold in simulated body fluid resulted in formation of apatite layers on the surface. Plus the entrapment method does not induce any cytotoxic response towards human fibroblast cell. This method provides a facile approach of obtaining 3D printed scaffold with good bioactivity thus has potential in biomimetic and tissue engineering.

Dry bacterial cellulose nanofiber (BC) sheet coated with poly(lactic acid) (PLA) was developed and characterized towards acute wound healing applications. This new approach of PLA coating on BC revealed enhanced physical and antibacterial properties. Commercial BC sheets originated from the manufacturing of nata de coco jelly were dried and coated with the PLA at various concentrations of 2, 4, 6, 8, 10 and 12 % w/v for the purpose of improving the mechanical properties and followed by loading of antiseptic such as benzalkonium chloride (BAC). PLA has been proposed for the use of coating materials at a concentration of 8 %, the biocomposite sheet started exhibiting a low moisture uptake, prolonged swelling in simulated wound fluid solution and high tear (9.17 Nm2/kg) and burst indices (32.5 kPa·m2/g). The 8 % PLA coating revealed porous fiber-like morphology as observed under scanning electron microscope. Therapeutic loading capacity of the BC/8 PLA was substantially higher than the pristine BC. Furthermore strong antimicrobial activities against Staphylococcus aureaus and Escherichia coli were observed for the BC/8PLA biocomposite film. These reports were clearly suggestive of the fact that synthetic biodegradable polymers, such as PLA, may be exploited for the synergistic combination with BC for antimicrobial and acute wound management. This new and modified fiber source material could reduce the dependency on plant based cellulose for more demanding biomedical applications such as wound healing materials, vascular graft, cartilage replacement, drug delivery and tissue engineering.

Correction for ‘Development and in vitro evaluation of κ-carrageenan based polymeric hybrid nanocomposite scaffolds for bone tissue engineering’ by Muhammad Umar Aslam Khan et al., RSC Adv., 2020, 10, 40529–40542. DOI: 10.1039/D0RA07446B.