Search

Maternal infections are among the main risk factors for cognitive impairments in the offspring. Zika virus (ZIKV) can be transmitted vertically, causing a set of heterogeneous birth defects, such as microcephaly, ventriculomegaly and corpus callosum dysgenesis. Nuclear distribution element like‐1 (Ndel1) oligopeptidase controls crucial aspects of cerebral cortex development underlying cortical malformations. Here, we examine Ndel1 activity in an animal model for ZIKV infection, which was associated with deregulated corticogenesis. We observed here a reduction in Ndel1 activity in the forebrain associated with the congenital syndrome induced by ZIKV isolates, in an in utero and postnatal injections of different inoculum doses in mice models. In addition, we observed a strong correlation between Ndel1 activity and brain size of animals infected by ZIKV, suggesting the potential of this measure as a biomarker for microcephaly. More importantly, the increase of interferon (IFN)‐beta signaling, which was used to rescue the ZIKV infection outcomes, also recovered Ndel1 activity to levels similar to those of uninfected healthy control mice, but with no influence on Ndel1 activity in uninfected healthy control animals. Taken together, we demonstrate for the first time here an association of corticogenesis impairments determined by ZIKV infection and the modulation of Ndel1 activity. Although further studies are still necessary to clarify the possible role(s) of Ndel1 activity in the molecular mechanism(s) underlying the congenital syndrome induced by ZIKV, we suggest here the potential of monitoring the Ndel1 activity to predict this pathological condition at early stages of embryos or offspring development, during while the currently employed methods are unable to detect impaired corticogenesis leading to microcephaly. Ndel1 activity may also be possibly used to follow up the positive response to the treatment, such as that employing the IFN‐beta that is able to rescue the ZIKV‐induced brain injury. [ABSTRACT FROM AUTHOR]

Objective. Ectopic posterior pituitary gland (EPP) is usually characterized by an abnormal pituitary stalk and hypoplasia of the anterior hypophysis. The genetic mechanisms involved in the development of EPP remain uncertain. The aim of this study is to determine whether mutations in the three genes, PROP-1, LHX2, and POU1F1, are associated with the risk for and the characteristics of EPP. Methods. In the Endocrinology Outpatient Clinic of "Dr. Behcet Uz" Children's Hospital, 27 patients with EPP were submitted to sequencing analyses of the PROP-1, LHX2, and POU1F1 genes. Results. Growth hormone, thyrotropin, corticotropin, gonadotropin, and vasopressin deficiency were observed in 22 (81.5%), 23 (85.2%), 17 (63%), 14 (51.9%), and two (7.4%) patients. Thirteen patients (48.1%) presented with hyperprolactinemia. Fourteen patients (51%) had a history of birth dystocia, and 12 cases (42.1%) had a history of breech presentation. Central nervous system abnormalities included five cases with corpus callosum agenesis, one case with schizencephaly, and one case with Chiari type 1 malformation. We identified a homozygous p.S109* mutation in exon 2 in one male patient with EPP and two different PROP1 gene polymorphisms (A142T or c.109+3 G>A polymorphism) in thirteen patients. Conclusions. Our results suggest that PROP1 gene abnormalities might explain the genetic mechanisms involved in the development of EPP. [ABSTRACT FROM AUTHOR]

An injectable hydrogel formulation is developed utilizing low- and high-molecular-weight chitosan (LCH and HCH) incorporated with curcumin and α-tocopherol-loaded liposomes (Lip/Cur+Toc). Cur and Toc releases are delayed within the hydrogels. The injectability of hydrogels is proved via rheological analyses. In vitro studies are conducted using human dental pulp stem cells (hDPSCs) and human gingival fibroblasts (hGFs) to examine the biological performance of the hydrogels toward endodontics and periodontics, respectively. The viability of hDPSCs treated with the hydrogels with Lip/Cur+Toc is the highest till day 14, compared to the neat hydrogels. During odontogenic differentiation tests, alkaline phosphatase (ALP) enzyme activity of hDPSCs is induced in the Cur-containing groups. Biomineralization is enhanced mostly with Lip/Cur+Toc incorporation. The viability of hGFs is the highest in HCH combined with Lip/Cur+Toc while wound healing occurs almost 100% in both (Lip/Cur+Toc@LCH and Lip/Cur+Toc@HCH) after 2 days. Antioxidant activity of Lip/Cur+Toc@LCH on hGFs is significantly the highest among the groups. Antimicrobial tests demonstrate that Lip/Cur+Toc@LCH is more effective against Escherichia coli whereas so is Lip/Cur+Toc@HCH against Staphylococcus aureus. The antimicrobial mechanism of the hydrogels is investigated for the first time through various computational models. LCH and HCH loaded with Lip/Cur+Toc are promising candidates with multi-functional features for endodontics and periodontics., (© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.)

Cyanophycin (CGP) is a polypeptide consisting of amino acids-aspartic acid in the backbone and arginine in the side chain. Owing to its resemblance to cell adhesive motifs in the body, it can be considered suitable for use in biomedical applications as a novel component to facilitate cell attachment and tissue regeneration. Although it has vast potential applications, starting with nutrition, through drug delivery and tissue engineering to the production of value-added chemicals and biomaterials, CGP has not been brought to the industry yet. To develop scaffolds using CGP powder produced by bacteria, its properties (e.g., biocompatibility, morphology, biodegradability, and mechanical strength) should be tailored in terms of the requirements of the targeted tissue. Crosslinking commonly stands for a primary modification method for renovating biomaterial features to these extents. Herein, we aimed to crosslink CGP for the first time and present a comparative study of different methods of CGP crosslinking including chemical, physical, and enzymatic methods by utilizing glutaraldehyde (GTA), UV exposure, genipin, 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS), and monoamine oxidase (MAO). Crosslinking efficacy varied among the samples crosslinked via the different crosslinking methods. All crosslinked CGP were non-cytotoxic to L929 cells, except for the groups with higher GTA concentrations. We conclude that CGP is a promising candidate for scaffolding purposes to be used as part of a composite with other biomaterials to maintain the integrity of scaffolds. The initiative study demonstrated the unknown characteristics of crosslinked CGP, even though its feasibility for biomedical applications should be confirmed by further examinations. KEY POINTS: • Cyanophycin was crosslinked by 5 different methods • Crosslinked cyanophycin is non-cytotoxic to L929 cells • Crosslinked cyanophycin is a promising new material for scaffolding purposes., (© 2024. The Author(s).)

Introduction: Increasingly, research groups have been studying the association of serum vitamin D and metabolic health indicators, especially in patients with obesity. We compared the serum 25-hydroxyvitamin D (25(OH)D) concentrations in children and adolescents who had obesity and hepatosteatosis with children and adolescents who had obesity without hepatosteatosis and investigated the relationship between serum 25(OH)D concentrations and severity of hepatosteatosis. We also aimed to assess the effect of vitamin D treatment after 6 months on hepatosteatosis and liver biochemistry., Methods: One hundred thirty-three patients with obesity (body mass index [BMI] >+2 standard deviations [SDs] for their age and gender) and vitamin D deficiency (serum 25(OH)D <12 ng/mL) were recruited. Anthropometric measurements, biochemical parameters (serum calcium, phosphate, alkaline phosphatase, parathyroid hormone, 25(OH)D, glucose and insulin concentrations), and ultrasonographic findings of hepatosteatosis were recorded before and 6 months after Vitamin D treatment. χ2, Student's t tests, and multivariate analysis were performed., Results: Grade 1, 2, and 3 hepatosteatosis at baseline was present in 51 (38.4%), 43 (32.3%), and 10 (7.5%) subjects, respectively. Mean (± SD) serum 25(OH)D concentrations were significantly lower in those with hepatosteatosis (8.4 ± 2.4 ng/mL) compared with those without hepatosteatosis (9.9 ± 2.4 ng/mL, p < 0.005). Multivariable logistic regression analysis showed serum 25(OH)D concentration was the independent predictor for hepatosteatosis (p < 0.005), whereas age, sex, weight SD, BMI SD, and homeostasis model of assessment (HOMA)-insulin resistance (IR) were not (p > 0.05). There was no significant difference in BMI SD, HOMA-IR, and liver enzymes between subjects with and without hepatosteatosis (p > 0.05). Despite improvement in serum 25(OH)D concentrations at 6 months post-treatment (34.7 ± 10.6 ng/mL vs. 8.7 ± 2.4 ng/mL; p < 0.0001), there was no significant difference in the proportion of patients with different severity of hepatosteatosis as compared to before treatment (p = 0.88)., Conclusion: Serum 25(OH)D concentrations were lower in children and adolescents with obesity and hepatic steatosis as compared to those without hepatic steatosis, with an inverse association between the severity of hepatosteatosis and serum 25(OH)D concentrations. Vitamin D treatment in children and adolescents with obesity and hypovitaminosis D did not improve severity of hepatic steatosis on ultrasonography at 6 months., (© 2023 S. Karger AG, Basel.)

Dental tissue infections have been affecting millions of patients globally leading to pain, severe tissue damage, or even tooth loss. Commercial sterilizers may not be adequate to prevent frequent dental infections. Antimicrobial hydrogels have been introduced as an effective therapeutic strategy for endodontics and periodontics since they have the capability of imitating the native extracellular matrix of soft tissues. Hydrogel networks are considered excellent drug delivery platforms due to their high-water retention capacity. In this regard, drugs or nanoparticles can be incorporated into the hydrogels to endow antimicrobial properties as well as to improve their regenerative potential, once biocompatibility criteria are met avoiding high dosages. Herein, novel antimicrobial hydrogel formulations were discussed for the first time in the scope of endodontics and periodontics. Such hydrogels seem outstanding candidates especially when designed not only as simple volume fillers but also as smart biomaterials with condition-specific adaptability within the dynamic microenvironment of the defect site. Multifunctional hydrogels play a pivotal role against infections, inflammation, oxidative stress, etc. along the way of dental regeneration. Modern techniques ( e.g. , 3D and 4D-printing) hold promise to develop the next generation of antimicrobial hydrogels together with their limitations such as infeasibility of implantation.

3D printing offers an exciting opportunity to fabricate biological constructs with specific geometries, clinically relevant sizes, and functions for biomedical applications. However, successful application of 3D printing is limited by the narrow range of printable and bio-instructive materials. Multicomponent hydrogel bioinks present unique opportunities to create bio-instructive materials able to display high structural fidelity and fulfill the mechanical and functional requirements for in situ tissue engineering. Herein, 3D printable and perfusable multicomponent hydrogel constructs with high elasticity, self-recovery properties, excellent hydrodynamic performance, and improved bioactivity are reported. The materials' design strategy integrates fast gelation kinetics of sodium alginate (Alg), in situ crosslinking of tyramine-modified hyaluronic acid (HAT), and temperature-dependent self-assembly and biological functions of decellularized aorta (dAECM). Using extrusion-based printing approach, the capability to print the multicomponent hydrogel bioinks with high precision into a well-defined vascular constructs able to withstand flow and repetitive cyclic compressive loading, is demonstrated. Both in vitro and pre-clinical models are used to show the pro-angiogenic and anti-inflammatory properties of the multicomponent vascular constructs. This study presents a strategy to create new bioink whose functional properties are greater than the sum of their components and with potential applications in vascular tissue engineering and regenerative medicine., (© 2023 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.)

Use of injectable hydrogels attract attention in the regeneration of dental pulp due to their ability to fill non-uniform voids such as pulp cavities. Here, gelatin methacrylate/thiolated pectin hydrogels (GelMA/PecTH) carrying electrospun core/shell fibers of melatonin (Mel)-polymethylmethacrylate (PMMA)/Tideglusib (Td)-silk fibroin (SF) were designed as an injectable hydrogel for vital pulp regeneration, through prolonged release of Td and Mel to induce proliferation and odontoblastic differentiation of dental pulp stem cells (DPSC). H NMR and FTIR confirmed methacrylation of Gel and thiolation of Pec. Addition of PMMA/SF increased degradation and water retention capacities of GelMA/PecTH. Rheological analyses and syringe tests proved the injectability of the hydrogel systems. Release studies indicated that Td and Mel were released from the fibers inside the hydrogels sequentially due to their specific locations. This release pattern from the hydrogels resulted in DPSC proliferation and odontogenic differentiation in vitro. Gene expression studies showed that the upregulation of DMP1, DSPP, and Axin-2 genes was promoted by GelMA/PecTH carrying PMMA/SF loaded with Mel (50 µg/mL) and Td (200 nM), respectively. Our results suggest that this hydrogel system holds promise for use in the regeneration of pulp tissue., 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 © 2022 Elsevier B.V. All rights reserved.)

Vitamin C&E (VtC&VtE)-loaded bilayer wound dressings were prepared using bacterial cellulose (BC) synthesized by Acetobacter species and pullulan (PUL). VtC-containing PUL hydrogels (100 μg/mL) were immobilized onto BC by crosslinking. BC/PUL-VtC was loaded with VtE (100 μM in ethanol) by immersion for 2 h. No delamination between the layers was observed via SEM. Despite the porous inner PUL side, the outer BC side exhibited nanofibrous morphology serving as barriers to prevent microorganism invasion. Equilibrium water content of BC/PUL was above 85 % due to the hydrogel characteristics of PUL side, suitable to absorb exudate in wound bed. PUL layer lost >90 % of its weight in simulated wound fluid and > 99 % in lysozyme solution within 14 days, mediating co-release of VtC&VtE. Thin BC side possessed adequate strength (⁓22 MPa) and strain (>30 %) to endure against tensile stress generated by bending on wound surface without rupture, whereas thick PUL side was flexible (>70 % strain) to fit into wound bed under compressive stress without causing harm. In vitro studies using L929 fibroblasts elucidated PUL side was anti-adhesive and removable. Synergistic effect of VtC&VtE on antioxidant activity, wound closure, and collagen synthesis was observed. Thus, BC/PUL-VtC/VtE hold promise as cheap and eco-friendly temporary wound dressing., 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 © 2022 Elsevier B.V. All rights reserved.)

Simvastatin (SIM)-loaded and human decellularized adipose tissue (DAT)-coated porous hydroxyapatite (HAp) microspheres were developed for the first time to investigate their potential on bone regeneration. Microspheres were loaded with SIM and then coated with DAT for modifying SIM release and improving their biological response. HAp microspheres were prepared by water-in-oil emulsion method using camphene (C 10 H 16 ) as porogen followed by camphene removal by freeze-drying and sintering at 1200°C for 3 h. Sintered HAp microspheres with an average particle size of ~400 µm were porous and spherical in shape. Microspheres were incubated with 1, 2.5, and 5 mg/ml SIM stock solutions for drug loading, and drug loading was determined as 7.5 ± 0.79, 20.41 ± 1.93, and 46.26 ± 0.29 µg SIM/mg microspheres, respectively. SIM loading increased with the increase of the initial SIM loading amount. Faster SIM release was observed in DAT-coated microspheres compared to bare counterparts. Higher SaoS-2 cell attachment and proliferation were observed on DAT-coated microspheres. Significantly higher alkaline phosphatase activity of SaoS-2 cells was observed on DAT-coated microspheres containing 0.01 mg/ml SIM than all other groups (p < 0.01). DAT-coated microspheres loaded with SIM at low doses hold promise for bone tissue engineering applications., (© 2022 Wiley Periodicals LLC.)

Mimicking extracellular matrix (ECM) of native tissue by tissue-engineered constructs is critical to induce regeneration of the damaged site. In this study, coaxial electrospinning of core/shell poly(methyl methacrylate) (PMMA)/silk fibroin (SF) fibers was optimized for the first time to provide ECM-like microenvironment for new tissue formation by utilization of a new collector design for obtaining homogeneously deposited mats from the collector screen. SF-shell was produced to increase cell-affinity of fiber surfaces whereas PMMA-core was designed to support the tissue mechanically during regeneration. PMMA/SF membranes were characterized. Morphology of core/shell PMMA/SF fibers resembled neat SF (ribbon-like) fibers rather than neat PMMA (cylindrical) fibers since SF constituted the shell part. The average diameter of PMMA/SF fibers (2.51 μm) lied in between the neat counterparts (PMMA: 2.40 μm and SF: 2.84 μm). The morphological and chemical properties affected the water contact angle and porosity of the mats, leading to the highest hydrophilicity for SF mats and the highest porosity for PMMA mats among the groups. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirmed the core/shell structure of PMMA/SF fibers. The combination of these remarkably different polymers (synthetic, hydrophobic, brittle PMMA and natural, hydrophilic, flexible SF) resulted in intermediate mechanical properties of PMMA/SF mats both in dry and wet conditions by preserving fibrous and porous structures in the core/shell form unlike the neat mats. Thermogravimetric analyses (TGA) showed the highest mass loss for PMMA/SF mats which lost 13.9% of their initial weight unlike the neat counterparts. In vitro hydrolytic & enzymatic degradation studies revealed that PMMA/SF had the weight loss between those observed for SF and PMMA mats in the presence and absence of enzymes while possessing the highest water uptake capacity. SEM examinations of mats after 14 days of hydrolytic degradation demonstrated the SF-shell of the fibers were fused at the intercept points of the PMMA/SF network while the PMMA-core acted as a separating backbone and preserved fibrous, and hence porous architecture of the mats. Cell culture studies demonstrated that human dental pulp stem cells (DPSC) were able to attach and proliferated on PMMA/SF mats while a lower degree of cell spreading on PMMA mats was observed. DPSC adhesion was improved by SF-shell in PMMA/SF group. In conclusion, electrospun composite mats composed of core/shell PMMA/SF fibers could be considered a promising candidate for tissue engineering applications and drug delivery strategies., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Injectable systems receive attention in endodontics due to the complicated and irregular anatomical structure of root canals. Here, injectable Tideglusib (Td)-loaded hyaluronic acid hydrogels (HAH) incorporated with Rg1-loaded chitosan microspheres (CSM) were developed for vital pulp regeneration, providing release of Td and Rg1 to trigger odontoblastic differentiation of human dental pulp stem cells (DPSC) by Td and vascularization of pulp by Rg1. The optimal concentrations were determined as 90 nM and 50 μg/mL for Td and Rg1, and loaded in HA and CSM in HAH, respectively. Odontogenic (COL1A1, ALP, OCN, Axin-2, DSPP, and DMP1) and angiogenic (VEGFA, VEGFR2, and eNOS) differentiation of DPSC cultured in the presence of hydrogels was shown at gene expression level. Our results suggest that our injectable hydrogel formulation has potential to improve strategies for vital pulp regeneration. In vivo evaluations are needed to test the feasibility and potential of these hydrogels for vital pulp regeneration., (Copyright © 2021. Published by Elsevier Ltd.)

Barrier membranes are used in periodontal tissue engineering for successful neo-bone tissue formation and prevention of bacterial colonization. We aimed to prepare and characterize novel 7% boron-modified bioactive glass (7B-BG) containing bilayered membrane for this end. We hypothesized that presence of 7B-BG could promote structural and biological properties of guided bone regeneration (GBR) membrane. Cellulose acetate (CA) layer was prepared by solvent casting, and functionally graded layer of CA/gelatin/BG nanoparticles was prepared by electrospinning. 0B-BG, and 7B-BG were synthesized by quick alkali-mediated sol-gel method and were characterized by scanning electron microscopy (SEM) and Fourier-transform Raman spectroscopy. Membranes were cross-linked with glutaraldehyde to preserve their stability. SEM analysis showed the asymmetric nature of membranes consisting of a smooth membrane layer and a rough surface composed of 0B-BG and 7B-BG containing nanofibres. 7B-BG addition increased surface wettability (from 110.5° ± 0.8 to 73.46° ± 7.6) and biodegradability of the membranes. Additionally, a significant increase in Ca-P layer formation was observed in 7B-BG containing group after 1-week incubation in stimulated body fluid. 7B-BG incorporation resulted in a decrease in tensile strength and Young's modulus values. Human dental pulp stem cells showed better attachment, spreading, and proliferation on 7B-BG containing bilayered membranes. Osteogenic differentiation analysis revealed higher alkaline phosphatase (ALP) enzyme activity of cells (~1.5-fold), higher intracellular calcium deposition (approximately twofold), and higher calcium deposition revealed by Alizarin red staining on 7B-BG containing bilayered membranes. Overall, results suggested that functionally graded bilayered membranes hold potential for GBR applications in regenerative dentistry., (© 2019 John Wiley & Sons, Ltd.)

Tissue engineering can benefit from wide variety of materials produced by microorganisms. Natural origin materials often possess good biocompatibility, biodegradability with sustainable production by microorganisms. A phytoplankton, diatom, produces an amorphous silica shell that can be obtained by a cost efficient production process. Diatom shells (DS) are promising for bone tissue engineering since silicon enhances bone regeneration. Biocompatible and biodegradable biopolymers with microorganism origin can be combined with DS to produce tissue engineering constructs. In this study, a novel multifunctional 3D fibrous scaffold for bone tissue engineering was produced by co-electrospinning system; antibiotic loaded poly(hydroxybutyrate-co-hydroxyvalerate)/poly(ε-caprolactone) (PHBV/PCL) fibers and DS incorporated pullulan (PUL) fibers. Controlled release of cefuroxime axetil (CA) from DS and scaffolds were investigated upon loading CA into DS or PHBV/PCL fibers. Purified DS were characterized with ESCA, SEM, and EDX analyses while scaffolds were evaluated in terms of morphology, porosity, degradation, calcium deposition, water retention and mechanical properties. In vitro studies showed that scaffolds bearing DS have improved human osteosarcoma (Saos-2) cell viability. Developed co-electrospun scaffold showed higher osteocompatibility with better cell spreading and cell distribution. Results showed that DS loaded, co-electrospun scaffold having both hydrophobic and hydrophilic characteristics can be a promising biomaterial for bone tissue engineering., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Dental caries is a dental disease affecting public health, which results in many socio-economic consequences. This disease causes loss of tooth hard tissue and subsequent inflammation and loss of the dental pulp. In this study, it was aimed to develop and characterize boron (B) modified bioactive glass nanoparticles (BG-NPs) containing cellulose acetate/oxidized pullulan/gelatin (CA/ox-PULL/GEL) three dimensional scaffolds with tubular morphology for dentin regeneration. 3D nanobiocomposite structures were prepared by thermally induced phase separation and porogen leaching methods and characterized by in vitro degradation analysis, water absorption (WA) capacity measurement, SEM, in vitro biomineralization analysis, porosity measurement and mechanical tests. Scaffolds lost about (30-40)% of their weight during one month and WA capacity decreased with increase in immersion time in phosphate buffer solution (PBS) during one month. According to SEM, aligned and tubular structures were formed with mean diameter of about 11 μm, and BG-NPS were distributed evenly in all parts of the scaffolds. Scaffolds (without BG-NPs) possessed the highest porosity percentage. Addition of 10% BG-NPs improved the mechanical properties of scaffolds. Scaffolds surfaces were fully covered by calcium phosphate (Ca-P) deposits after conditioning in simulated body fluid for 14 days with higher quantity of deposition in groups with inclusion of B-BG-NPs. Human dental pulp stem cells (hDPSCs) were isolated from third molar teeth and used in cell culture studies. In all groups, cells adhered well 1 day after culture. Group B14-10 showed a slight increase of proliferation than group (without BG-NPs) after 7 days of incubation. Alkaline phosphatase activity (ALP) and intracellular calcium amounts increased significantly 14 days after incubation with highest values in B14-10 and B14-20 groups. Confocal laser scanning microscopy (CSLM) analysis, showed that cells on B14-10 and B21-10 scaffold groups, spread more 14 days after culture, and they also possessed extended processes specific to odontoblasts. Alizarin Red quantification showed that the highest calcium deposition was observed on B14-10 scaffolds. Immunohistochemical and Von Kossa stainings showed that scaffolds positively affected the odontoblastic differentiation of the hDPSCs. In this work, results showed that boron modified BG-NPs (B-BG-NPs) incorporated dentin-like constructs bring a new approach for dental tissue engineering applications., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this study, novel porous three-dimensional (3D) scaffolds from silk fibroin (SF) and functionalized (amidated and oxidized) citrus pectin (PEC) were developed for skin tissue engineering applications. Crosslinking was achieved by Schiff's reaction in borax presence as crosslinking coordinating agent and CaCl 2 addition. After freeze-drying and methanol treatment, plasma treatment (10 W, 3 min) was applied to remove surface skin layer formed on scaffolds. 3D matrices had high porosity (83%) and interconnectivity with pore size about 120 µm that providing suitable microenvironment for cells. Modifications on PEC chain and crosslinking of scaffolds were verified by fourier-transform infrared spectroscopy (FTIR) analysis and spectrophotometric assay. Scaffolds showed low weight loss (21.3% in 40 days) and high water uptake ability in phosphate-buffered saline (800% in 24 h). Mechanical properties of 3D matrices satisfied the stability of scaffolds under compressive stress and supported adhesion, proliferation and penetration of fibroblast cells. Our results suggested that modified PEC-SF scaffolds would be proposed for use in tissue engineered skin dermal substitutes. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2625-2635, 2018., (© 2018 Wiley Periodicals, Inc.)

Natural polymer based fibrous scaffolds have been explored for bone tissue engineering applications; however, their inadequate 3-dimensionality and poor mechanical properties are among the concerns for their use as bone substitutes. In this study, pullulan (P) and cellulose acetate (CA), two polysaccharides, were electrospun at various P/CA ratios (P80/CA20, P50/CA50, and P20/CA80%) to develop 3D fibrous network. The scaffolds were then crosslinked with trisodium trimetaphosphate (STMP) to improve the mechanical properties and to delay fast weight loss. The lowest weight loss was observed for the groups that were crosslinked with P/STMP 2/1 for 10min. Fiber morphologies of P50/CA50 were more uniform without phase separation and this group was crosslinked most efficiently among groups. It was found that mechanical properties of P20/CA80 and P50/CA50 were higher than that of P80/CA20. After crosslinking strain values of P50/CA50 scaffolds were improved and these scaffolds became more stable. Unlike P80/CA20, uncrosslinked P50/CA50 and P20/CA80 were not lost in PBS. Among all groups, crosslinked P50/CA50 scaffolds had more uniform pores; therefore this group was used for bioactivity and cell culture studies. Apatite-like structures were observed on fibers after SBF incubation. Human Osteogenic Sarcoma Cell Line (Saos-2) seeded onto crosslinked P50/CA50 scaffolds adhered and proliferated. The functionality of cells was tested by measuring ALP activity of the cells and the results indicated their osteoblastic differentiation. In vitro tests showed that scaffolds were cytocompatible. To sum up, crosslinked P50/CA50 scaffolds were proposed as candidate cell carriers for bone tissue engineering applications., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Skin defects that are not able to regenerate by themselves are among the major problems faced. Tissue engineering approach holds promise for treating such defects. Development of tissue-mimicking-scaffolds that can promote healing process receives an increasing interest in recent years. In this study, 3-dimensional electrospun cellulose acetate (CA) pullulan (PULL) scaffolds were developed for the first time. PULL was intentionally used to obtain 3D structures with adjustable height. It was removed from the electrospun mesh to increase the porosity and biostability. Different ratios of the polymers were electrospun and analyzed with respect to degradation, porosity, and mechanical properties. It has been observed that fiber diameter, thickness and porosity of scaffolds increased with increased PULL content, on the other hand this resulted with higher degradation of scaffolds. Mechanical strength of scaffolds was improved after PULL removal suggesting their suitability as cell carriers. Cell culture studies were performed with the selected scaffold group (CA/PULL: 50/50) using mouse fibroblastic cell line (L929). In vitro cell culture tests showed that cells adhered, proliferated and populated CA/PULL (50/50) scaffolds showing that they are cytocompatible. Results suggest that uncrosslinked CA/PULL (50/50) electrospun scaffolds hold potential for skin tissue engineering applications., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Engineered nucleases such as zinc finger nucleases (ZFN) and transcription activator-like effector nucleases (TALEN) are one of the most promising tools for modifying genomes. These site-specific enzymes cause double-strand breaks that allow gene disruption or gene insertion, thereby facilitating genetic manipulation. The major problem associated with this approach is the labor-intensive procedures required to screen and confirm the cellular modification by nucleases. In this work, we produced a TALEN that targets the human CCR5 gene and developed a heteroduplex mobility assay for HEK 293T cells to select positive colonies for sequencing. This approach provides a useful tool for the quick detection and easy assessment of nuclease activity.

Objective: The lack of nocturnal decline in blood pressure (BP) is associated with an increase in cardiovascular events. Soluble CD40 ligand (sCD40L) is involved in the pathogenesis of risk factor-related vascular damage. The purpose of this study was to examine the relationship between vascular endothelial functions, carotid intima-media thickness (cIMT), plasma sCD40L levels and circadian BP profile in patients with essential hypertension., Material and Methods: The study population consisted of 81 essential hypertensive out-patients. BP dipping was defined as a night-to-day systolic and diastolic decrease >or=10%. Forty-seven dipper and 34 nondipper patients were compared. High sensitivity C-reactive protein (hs-CRP), sCD40L and urinary albumin were measured. Brachial artery flow-mediated dilatation (FMD) and cIMT was compared between the groups., Results: sCD40L level (3.28 +/- 2.08 and 2.30 +/- 1.99 ng/ml, respectively, P = 0.036) and urinary albumin concentration (36.7 +/- 20.1 and 23 +/- 29.7 mg/l, respectively, P < 0.0001) were higher in nondippers than in dippers. Serum hs-CRP levels were not significantly different. FMD was found higher in dippers than nondippers (11.8 +/- 3.9% and 6.6 +/- 2.2%, respectively, P < 0.0001). The average cIMT was significantly higher in nondippers than dippers (0.928 +/- 0.060 Vs. 0.734 +/- 0.134 mm; P < 0.0001)., Conclusions: Nondipper patern has an additional negative effect on endothelial functions in hypertensive patients. Nondippers have enhanced sCD40L levels, which may contribute to their increased susceptibility to develop vascular damage.