Developing and Screening of a Bacteria-Fighting and Moisture-Controlling Coccinia grandis and Poly(vinyl alcohol) Electrospun Nanofibrous Mat.

Nanofibers are extensively employed in the antimicrobial industry owing to their remarkable properties and diverse applications. Managing wounds poses a significant and enduring challenge for healthcare systems globally. This study aims to produce and evaluate electrospun nanofiber mats made from poly(vinyl alcohol) (PVA) and Coccinia grandis (C. grandis) leaf extract, highlighting the medicinal properties of this herbal product for potential biomedical applications (wound dressing). During the evaluations, a 60:40 ratio of PVA to leaf extract was found to be suitable, and the electrospinning process was utilized for production. Scanning electron microscopy was employed for morphological assessment, and an antibacterial assay was conducted against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) to evaluate cell cytotoxicity. Additionally, Fourier-transform infrared spectroscopy (FTIR) and moisture management behavior (moisture management test) analyses were performed on the fabricated electrospun nanofibrous mat. The formation of small beads was confirmed, with the nanofibers having an average diameter of 295.07 ± 0.0032 nm and a porosity of approximately 76%, which is adequate for oxygen circulation and air ventilation, ensuring skin breathability. Gram-positive bacteria (S. aureus) exhibited a zone of inhibition (ZOI) of 14 mm, while Gram-negative bacteria (E. coli) showed a ZOI of 10 mm, attributed to the presence of a thick peptidoglycan cell wall in Gram-positive bacteria with no cell toxicity (100% cell viability). FTIR confirms the formation of weak van der Waals bonds and represents H-bonds between PVA polymer and C. grandis leaf extract. Furthermore, according to the MMT analysis, the electrospun nanofibrous mat demonstrates rapid absorption and slow drying properties. Therefore, the produced electrospun nanofibrous mat could prove beneficial for wound dressing purposes.

Collagen/Nigella sativa/chitosan inscribed electrospun hybrid bio-nanocomposites for skin tissue engineering.

The sophisticated new tissue regeneration focused on nanocomposite with different morphologies achieved through advanced manufacturing technology with the inclusion of bio-inscribed materials has piqued the research community's interest. This research aims at developing hybrid bio-nanocomposites with collagen (Col), Nigella sativa (Ns) oil and chitosan (Cs) by a bi-layered green electrospinning on polyvinyl chloride (PVA) layer in a different ratio for tissue regeneration. Fiber morphologies through scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), moisture management, tensile test, antibacterial activity, cell cytotoxicity and wound healing through rabbit model of the fabricated hybrid bio-nanocomposites were investigated. It is worth noting that water-soluble Col (above 60% solution) does not form Taylor cones during electrospinning because unable to overcome the surface tension of the solution (viscosity) to form fibers. The results show that water soluble Col (50% solution) to Cs (25% solution) and Ns (25% solution) has good fiber formation with mean diameter 384 ± 27 nm and degree of porosity is 79%. The fast-absorbing and slow-drying hybrid bio-nanocomposites maintain a moist environment for wounds and allowing gaseous exchange for cell migration and proliferation by the synergistic effects of bio-polymers. All of the biopolymers in bio-nanocomposite improve the H-bonds, which accounts for enough tensile strength to withstand cell pulling force. The antibacterial ZOI concentrations against S. aureus and E. coli were 10 and 8 mm, respectively, which appeared to be sufficient to inhibit bacterial action with 100% cell viability (cytotoxicity). The synergistic effects of Ns and Cs improve tissue regeneration, while native Col improves antibacterial activity, and the rabbit model achieves approximately 84% wound closure in only 10 days, which is 1.5 times faster than the control model. So, the fabricated hybrid bio-composites may be useful for skin tissue engineering.

Fabrication of bio-inscribed (green) electrospun hybrid bio-nanocomposite by the novel bi-layer techniqueThe developed complex (fast absorbing and slow drying composite) absorbs exudate from the wound to provide a suitable moist environment for healing and tissue regenerationAntibacterial susceptibility is boosted by the synergistic effects of Nigella sativa and chitosan, while tissue regeneration is improved (approx. 10 days for rabbit model) by native collagen with no cytotoxicityWater soluble collagen (above 60% solution) will not produce fibers as unable to surmount the surface tension of the solution (viscosity) and increasing amount of Nigella sativa decrease the inhibition zone against gram-negative bacteria [Figure: see text].

Antibacterial multicomponent electrospun nanofibrous mat through the synergistic effect of biopolymers.

The endeavor was to adopt a facile bi-layered approach to fabricate a novel PVA-chitosan-collagen-licorice nanofibrous mat (PCCLNM) with maintaining the spinning parameters and conditions to assess the synergistic antibacterial action of two biopolymers and having properties for repairing tissues. Bonding behavior, morphological orientation, antibacterial activity, and moisture management features of the electrospun nanofibrous mat were investigated using various characterization techniques. The FTIR analysis of the manufactured nanofibrous mat revealed characteristic peaks of licorice, chitosan, collagen, and PVA polymer, confirming the presence of all polymers in the sample. Additionally, a scanning electron microscopy (SEM) image attributes the development of nanofibers with an average diameter for top and bottom sides were 219 and 188 nm respectively. Furthermore, moisture management tests (MMT) confirm PCCLNM's slow absorption and drying capabilities. Apart from that, a disk diffusion method was used to investigate antibacterial activity against the bacteria Staphylococcus aureus (S. aureus), which revealed a strong presence of antibacterial activity with a 20 mm zone of inhibition due to the chemical constituents of licorice and chitosan compound. The developed bio-nanocomposite could have a potential application as wound healing material.

Face Masks to Combat Coronavirus (COVID-19)-Processing, Roles, Requirements, Efficacy, Risk and Sustainability.

Increasingly prevalent respiratory infectious diseases (e.g., COVID-19) have posed severe threats to public health. Viruses including coronavirus, influenza, and so on can cause respiratory infections. A pandemic may potentially emerge owing to the worldwide spread of the virus through persistent human-to-human transmission. However, transmission pathways may vary; respiratory droplets or airborne virus-carrying particles can have a key role in transmitting infections to humans. In conjunction with social distancing, hand cleanliness, and other preventative measures, the use of face masks is considered to be another scientific approach to combat ubiquitous coronavirus. Different types of face masks are produced using a range of materials (e.g., polypropylene, polyacrylonitrile, polycarbonate, polyurethane, polystyrene, polyester and polyethylene) and manufacturing techniques (woven, knitted, and non-woven) that provide different levels of protection to the users. However, the efficacy and proper disposal/management of the used face masks, particularly the ones made of non-biodegradable polymers, pose great environmental concerns. This review compiles the recent advancements of face masks, covering their requirements, materials and techniques used, efficacy, challenges, risks, and sustainability towards further enhancement of the quality and performance of face masks.