Preparation and characterization of vancomycin-loaded chitosan/PVA/PEG hydrogels for wound dressing

This study describes a drug-loaded porous hydrogel for delivery of vancomycin. Hydrogels based on chitosan (CS), Polyvinyl alcohol (PVA) and Polyethylene glycol (PEG) were prepared by lyophilization. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and fourier transform infrared (FTIR) spectroscopy were used to characterize the structures. Water uptake percentage and vancomycin release were also measured. The antibacterial activity against Staphylococcus aureus was investigated. According to the results, mean pore diameter (MPD) was decreased by addition of PEG and reached to 1.3 ± 0.5 μ m. On the other hand, 43% decrease in water content of the hydrogels showed along with the incorporation of PEG. The inhibition zone confirmed antibacterial effect of the vancomycin-loaded hydrogels. The porous CS/PVA/PEG hydrogels containing vancomycin could be good candidates to potentially be used as wound dressing

Photocatalytic degradation of acid blue 74 by Co: WO3 nanoparticles: Kinetics and response surface methodology studies

Energy-efficient sol-gel synthesis was achieved through the microwave assisted self-combustion route to produce hexagonal Tungsten oxide semiconductor (WO3). The photocatalytic activity was enhanced by doping Cobalt (Co) into the crystalline structure of the nanoparticle, which were subsequently sintered at 400 °C for an hour. The structural and morphological properties of the Co-doped WO3 were revealed using X-ray diffraction (XRD) characterization. The nanoparticles exhibited an amorphous structure before annealing, due to the short heating time during combustion synthesis. Sintering the nanoparticle transformed the nanoparticle from a monoclinic phase to orthorhombic phase structure. Additional analysis techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectrum analysis (EDS).To assess the photocatalytic performance of these particles, Acid Blue 74 (AB 74) was employed in photodegradation experiments under UV light irradiation within a semi-continuous reactor.The photodegradation of dye molecules was evaluated utilizing a UV–Vis spectrophotometer, and the mineralization efficiency of the dye was determined through total organic carbon analysis (TOC). The results indicated that the dimension of the synthesized nano catalyst fell within the range of 70–120 nm, and it exhibited the ability to completely degrade a solution with an initial dye concentration of 20 ppm within 60 min. Various parameters affecting the photocatalytic reaction, including the photocatalyst dosage, initial dye concentration, pH and temperature of the dye solution were also investigated. The experiments were designed using Response surface methodology (RSM), through which a mathematical model for the dye removal process was developed

Electrospun Polycaprolactone/lignin-based Nanocomposite as a Novel Tissue Scaffold for Biomedical Applications

Background: Biopolymer scaffolds have received great interest in academic and industrial environment because of their supreme characteristics like biological, mechanical, chemical, and cost saving in the biomedical science. There are various attempts for incorporation of biopolymers with cheap natural micro- or nanoparticles like lignin (Lig), alginate, and gums to prepare new materials with enhanced properties. Methods: In this work, the electrospinning (ELS) technique as a promising cost-effective method for producing polymeric scaffold fibers was used, which mimics extracellular matrix structure for soft tissue engineering applications. Nanocomposites of Lig and polycaprolactone (PCL) scaffold produced with ELS technique. Nanocomposite containings (0, 5, 10, and 15 wt.%) of Lig were prepared with addition of Lig powder into the PCL solution while stirring at the room temperature. The bioactivity, swelling properties, morphological and mechanical tests were conducted for all the samples to investigate the nanocomposite scaffold features. Results: The results showed that scaffold with 10 wt.% Lig have appropriate porosity, biodegradation, minimum fiber diameter, optimum pore size as well as enhanced tensile strength, and young modulus compared with pure PCL. Degradation test performed through immersion of samples in the phosphate-buffer saline showed that degradation of PCL nanocomposites could accelerate up to 10% due to the addition of Lig. Conclusions: Electrospun PCL-Lig scaffold enhanced the biological response of the cells with the mechanical signals. The prepared nanocomposite scaffold can choose for potential candidate in the biomedical science

Incorporation of zeolite and silica nanoparticles into electrospun PVA/collagen nanofibrous scaffolds: The influence on the physical, chemical properties and cell behavior

Cartilage is under extensive investigation in tissue engineering research. Herein, we evaluated scaffolds prepared by composites of polyvinyl alcohol (PVA) and collagen incorporated with zeolite and silica nanoparticles (nZe and nSi). The scaffolds were prepared by the electrospinning method. The mean diameters of nanofibers were 0.61 ± 0.34 μm for PVA/collagen versuss 0.62 ± 0.22 μm and 0.66 ± 0.25 μm for the PVA/collagen/nZe and the PVA/collagen/nSi scaffolds, respectively. DAPI staining results revealed that cell proliferations on the PVA/collagen/nZe and PVA/collagen/nSi were strikingly higher than on the pure PVA/collagen. The results encouraged further investigation of PVA/collagen/nSi scaffolds as biomimetic platform for chondrocyte cells in tissue engineering