Cu-MOF loaded chitosan based freeze-dried highly porous dressings with anti-biofilm and pro-angiogenic activities accelerated Pseudomonas aeruginosa infected wounds healing in rats.

Metal-organic frameworks (MOFs)-based therapy opens a new area for antibiotic-drug free infections treatment. In the present study, chitosan membranes (CS) loaded with two concentrations of copper-MOF 10 mg/20 ml (Cu-MOF10/CS) & 20 mg/20 ml (Cu-MOF20/CS) were prepared by a simple lyophilization procedure. FTIR spectra of Cu-MOF10/CS and Cu-MOF20/CS dressings confirmed absence of any undesirable chemical changes after loading Cu-MOF. The SEM images of the synthesized materials (CS, Cu-MOF10/CS & Cu-MOF20/CS) showed interconnected porous structures. Cytocompatibility of the materials was confirmed by fibroblasts cells culturing and the materials were hemocompatible, with blood clotting index <5 %. Cu-MOF20/CS showed comparatively higher effective antibacterial activity against the tested strains; E. coli (149.2 %), P. aeruginosa (165 %) S. aureus (117.8 %) and MRSA (142 %) as compared to Amikacin, CS and Cu-MOF10/CS membranes. Similarly, Cu-MOF20/CS dressing significantly eradicated the biofilms; P. aeruginosa (37 %) and MRSA (52 %) respectively. In full thickness infected wound rat model, on day 23, Cu-MOF10/CS and Cu-MOF20/CS promoted wound healing up to 87.7 % and 82 % respectively. H&E staining of wounded tissues treated with Cu-MOF10/CS & Cu-MOF20/CS demonstrated enhanced neovascularization and re-epithelization along-with reduced inflammation, while trichrome staining exhibited increased collagen deposition. Overall, this study declares Cu-MOFs loaded chitosan dressings a multifunctional platform for the healing of infected wounds.

Acceptability of hepatitis C screening and treatment during pregnancy in pregnant women in Egypt, Pakistan, and Ukraine: A cross-sectional survey.

Chronic hepatitis C (HCV) in women of childbearing age is a major public health concern with ∼15 million women aged 15-49 years living with HCV globally in 2019. Evidence suggests HCV in pregnancy is associated with adverse pregnancy and infant outcomes. This includes ∼6% risk of infants acquiring HCV vertically, and this is the leading cause of HCV in children globally. However, few countries offer routine universal antenatal HCV screening, and direct-acting antivirals (DAAs) are not approved for pregnant or breastfeeding women although small clinical trials are ongoing. We conducted a survey of pregnant and postpartum women in 3 high HCV burden lower-middle-income countries to assess the acceptability of universal antenatal HCV screening and DAA treatment in the scenario that DAAs are approved for use in pregnancy. Pregnant and postpartum women attending antenatal clinics in Egypt, Pakistan, and Ukraine were invited to complete a survey and provide demographic and clinical data on their HCV status. Among the 630 women included (n=210 per country), 73% were pregnant and 27% postpartum, 27% were ever HCV antibody or PCR positive. Overall, 586 (93%) reported acceptability of universal antenatal HCV screening and 544 (88%) would take DAAs in pregnancy (92%, 98%, and 73% in Egypt, Pakistan, and Ukraine, respectively). Most said they would take DAAs in pregnancy to prevent vertical acquisition and other risks for the baby, and a smaller proportion would take DAAs for maternal cure. Our findings suggest that should DAAs be approved for use in pregnancy, the uptake of both HCV screening and DAA treatment may be high in women living in lower-middle-income countries.

Chitosan-sodium percarbonate-based hydrogels with sustained oxygen release potential stimulated angiogenesis and accelerated wound healing.

The prolonged hypoxic conditions hinder chronic wounds from healing and lead to severe conditions such as delayed re-epithelialization and enhanced risk of infection. Multifunctional wound dressings are highly required to address the challenges of chronic wounds. Herein, we report polyurethane-coated sodium per carbonate-loaded chitosan hydrogel (CSPUO2 ) as a multifunctional dressing. The hydrogels (Control, CSPU, and CSPUO2 ) were prepared by freeze gelation method and the developed hydrogels showed high porosity, good absorption capacity, and adequate biodegradability. The release of oxygen from the CSPUO2 hydrogel was confirmed by the increase in pH and a sustained oxygen release was observed over the period of 21 days, due to polyurethane (CSPU) coating. The CSPUO2 hydrogel exhibited around 2-fold increased angiogenic potential in CAM assay when compared with Control and CSPU dressing. CSPUO2 also showed good level of antibacterial efficacy against E. coli and S. aureus. In a full-thickness rat wound model, CSPUO2 hydrogel considerably accelerated wound healing with exceptional re-epithelialization granulation tissue formation less inflammatory cells and improved skin architecture highlighting the tremendous therapeutic potential of this hydrogel when compared with control and CSPU to treat chronic diabetic and burn wounds.

An alginate-Based tube gel delivering 2-deoxy-D-ribose for stimulation of wound healing.

Developing multifunctional wound dressings capable of inducing rapid angiogenesis and with antibacterial activity would be attractive for diabetic and superficial wound healing. Hydrogels delivered from tubes have several desirable features -they are easy to apply, keep the wound moist, reduce the entry of microorganisms and avoid the need for painful dressing removal. Previously we reported that 2 deoxy-D-ribose (2dDR) delivered from a variety of dressings is capable of promoting wound healing by stimulating angiogenesis. Alginate hydrogels are an ideal vehicle to deliver a bioactive agent capable of promoting wound healing. In this study we developed and evaluated a tube hydrogel capable of delivering 2dDR with the aim of achieving a stable, convenient to administer and biologically effective wound treatment. Further, we included the stabilizer 2-phenoxy ethanol which provided antimicrobial activity. We synthesized hydrogels by the Green method, using simple mixing of sodium alginate, propylene glycol, 2-phenoxy ethanol and 2dDR in water. FTIR (Fourier transformation infrared spectroscopy) analysis confirmed an absence of undesirable chemical changes in the gel components, and SEM images of the freeze-dried gels showed porous structures. When 2dDR alginate gel (2dDR-SA hydrogel) was placed in PBS at 37°C, almost 92% of 2dDR was released within 7 days. When tested on cultured cells, 2dDR-SA hydrogels did not inhibit metabolic activity or proliferation, achieving up to 90 and 98% of control respectively over 7 days. 2dDR-SA hydrogel also showed anti-bacterial activity against E. coli, Pseudomonas aeruginosa, Staphylococcus aureus, and MRSA which was attributable to the stabilizer 2-phenoxy ethanol in the hydrogel. Stimulation of angiogenesis in the chorioallantoic membrane assay by 2dDR-SA hydrogel was found to be significant compared to the blank-SA. Wound healing potential was studied in full-thickness wounds in rats where acceleration of wound healing was seen. H&E staining of the wound tissue showed an enhanced number of blood vessels and re-epithelization, and a reduced number of inflammatory cells in 2dDR-SA treated animals compared to blank-hydrogels while Masson's trichrome staining showed increased collagen deposition. In summary we describe a convenient to apply hydrogel which has promise for use in a range of superficial skin wounds including applications in chronic wound care.

Zinc oxide loaded chitosan-elastin-sodium alginate nanocomposite gel using freeze gelation for enhanced adipose stem cell proliferation and antibacterial properties.

Hydrogels have been the material of choice for regenerative medicine applications due to their biocompatibility that can facilitate cellular attachment and proliferation. The present study aimed at constructing a porous hydrogel composite scaffold (chitosan, sodium alginate and elastin) for the repair of chronic skin wounds. Chitosan-based hydrogel incorporating varying concentrations of zinc oxide nanoparticles i.e. ZnO-NPs (0, 0.001, 0.01, 0.1 and 1 % w/w) as the antimicrobial agent tested against Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) exhibited good antibacterial activities. ZnO-NPs were characterized by UV visible spectroscopy, Scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Fabricated gels were characterized by SEM analysis, FTIR, XRD, swelling ratio, degradation behavior and controlled release kinetics of ZnO-NPs. In vitro cytocompatibility of the composite was investigated using human adipose stem cells (ADSCs) by MTT and lactate dehydrogenase (LDH) assay, further assessed by SEM analysis and PKH26 staining. The SEM and XRD analysis confirmed the successful loading of ZnO-NPs into these scaffolds. Fluorescence PKH26 stained images and SEM analysis of ADSCs seeded scaffolds revealed biocompatible nature. The findings suggested that the developed composite gels have potential clinically for tissue engineering and chronic wound treatment.

Heparin-Loaded Alginate Hydrogels: Characterization and Molecular Mechanisms of Their Angiogenic and Anti-Microbial Potential.

Background: Chronic wounds continue to be a global concern that demands substantial resources from the healthcare system. The process of cutaneous wound healing is complex, involving inflammation, blood clotting, angiogenesis, migration and remodeling. In the present study, commercially available alginate wound dressings were loaded with heparin. The purpose of the study was to enhance the angiogenic potential of alginate wound dressings and analyze the antibacterial activity, biocompatibility and other relevant properties. We also aimed to conduct some molecular and gene expression studies to elaborate on the mechanisms through which heparin induces angiogenesis. Methods: The physical properties of the hydrogels were evaluated by Fourier transform infrared spectroscopy (FTIR). Swelling ability was measured by soaking hydrogels in the Phosphate buffer at 37 °C, and cell studies were conducted to evaluate the cytotoxicity and biocompatibility of hydrogels in NIH3T3 (fibroblasts). Real-time PCR was conducted to check the molecular mechanisms of heparin/alginate-induced angiogenesis. The physical properties of the hydrogels were evaluated by Fourier transform infrared spectroscopy (FTIR). Results: FTIR confirmed the formation of heparin-loaded alginate wound dressing and the compatibility of both heparin and alginate. Among all, 10 µg/mL concentration of heparin showed the best antibacterial activity against E. coli. The swelling was considerably increased up to 1500% within 1 h. Alamar Blue assay revealed no cytotoxic effect on NIH3T3. Heparin showed good anti-microbial properties and inhibited the growth of E. coli in zones with a diameter of 18 mm. The expression analysis suggested that heparin probably exerts its pro-angiogenetic effect through VEGF and cPGE. Conclusions: We report that heparin-loaded alginate dressings are not cytotoxic and offer increased angiogenic and anti-bacterial potential. The angiogenesis is apparently taken through the VEGF pathway.