Fabrication of Nanofibers Based on Hydroxypropyl Starch/Polyurethane Loaded with the Biosynthesized Silver Nanoparticles for the Treatment of Pathogenic Microbes in Wounds

Fabrication of electrospun nanofibers based on the blending of modified natural polymer, hydroxyl propyl starch (HPS) as one of the most renewable resources, with synthetic polymers, such as polyurethane (PU) is of great potential for biomedical applications. The as-prepared nanofibers were used as antimicrobial sheets via blending with biosynthesized silver nanoparticles (AgNPs), which were prepared in a safe way with low cost using the extract of Nerium oleander leaves, which acted as a reducing and stabilizing agent as well. The biosynthesized AgNPs were fully characterized by various techniques (UV-vis, TEM, DLS, zeta potential and XRD). The obtained results from UV-vis depicted that the AgNPs appeared at a wavelength equal to 404 nm affirming the preparation of AgNPs when compared with the wavelength of extract (there are no observable peaks). The average particle size of the fabricated AgNPs that mediated with HPS exhibited a very small size (less than 5 nm) with excellent stability (more than −30 mv). In addition, the fabricated nanofibers were also fully characterized and the obtained data proved that the diameter of nanofibers was enlarged with increasing the concentration of AgNPs. Additionally, the findings illustrated that the pore sizes of electrospun sheets were in the range of 75 to 350 nm. The obtained results proved that the presence of HPS displayed a vital role in decreasing the contact angle of PU nanofibers and thus, increased the hydrophilicity of the net nanofibers. It is worthy to mention that the prepared nanofibers incorporated with AgNPs exhibited incredible antimicrobial activity against pathogenic microbes that actually presented in human wounds. Moreover, P. aeruginosa was the most sensitive species to the fabricated nanofibers compared to other tested ones. The minimal inhibitory concentrations (MICs) values of AgNPs-3@NFs against P. aeruginosa, and E. faecalis, were 250 and 500 mg/L within 15 min, respectively.

Electrospun Nanofibers for Scheming Water Pollution

Water pollution is one of the key global problems which require immediate attention. Worldwide, it is predicted that more than 50% of countries will encounter water scarcities by 2025 which will increase to 75% by 2075. Each year more than 5 million people die due to water-borne diseases. The threat due to pollution by industries, exponential population growth, urbanization, by pathogenic microorganisms from human and animal waste, etc. The rise in water pollution and its subsequent effects on human health and environment is a matter of great concern. The water pollutants ought to be removed to improve water quality for human use. Nanoparticles or zero dimensional materials have been extensively studied since long, whereas one dimensional material (nanorods, nanotubes, nanowires, or nanofibers) have recently grabbed a lot of interest from global researchers. Nanofibers having large aspect ratio are grabbing incredible attention owing to dependency of physical property on directionality having high porosity and surface area as compared to normal fibers.

Electrospun Nanofibers for Drug Delivery Applications

Nanofiber systems with various composition and biological properties have been extensively studied for various biomedical applications. The electrospinning process has been regarded as one of the versatile techniques to prepare nano to microfibers. The electrospun nanofibers are being used especially in textile industries, sensors, filters, protective clothing, energy storage materials, and biomedical applications. In the last decade, electrospun nanofibers have been highly investigated for drug delivery systems to achieve a therapeutic effect in specifically targeted sites. Various drugs or biomolecules can be easily loaded into the electrospun nanofibers by direct or indirect methods. The proper selection of polymers (or blends of various polymers), drugs, solvents to prepare the composite nanofibers with desired morphology are the tools in enhancing the bioavailability, stability, and bioactivity of drugs.