关键词: 壳聚糖, 聚乙烯醇, 甘油, 纳米纤维膜, 亲水性, 溶胀性

Abstract: Medical dressings are a common medical device, playing a significant role in the medical realm. It has a wide range of applications in the treatment, healing, and infection control of trauma and surgical wounds. Research has found that wounds can heal better and faster in a moist environment. Hence, an ideal medical dressing should maintain optimal moisture levels at the wound site and effectively absorb exudates. Serving as a barrier against microorganisms, medical dressings must possess robust mechanical properties, flexibility to conform to diverse wound shapes, and effective antibacterial qualities to expedite the healing process.
Electrospinning, a technique that utilizes a high-voltage electrostatic field to produce ultrafine fibers, has attracted much attention due to the highly similar structure of the nanofiber membrane to the natural extracellular matrix of the human body. Electrospinning usually uses natural or synthetic polymer materials as raw materials, most of which have good biocompatibility, can be compatible with human tissues, and reduce allergic reactions to patients. By modifying the membrane's surface, adjusting the electrospun material, or incorporating drugs, we can create specialized functional dressings tailored to diverse application scenarios, thus offering convenience to both medical professionals and patients Consequently, further investigation and utilization of nanofiber membrane medical dressings hold substantial clinical importance and promise for the future
Chitosan (CS), a multifunctional biomaterial, is renowned for its non-toxicity, biodegradability, and excellent biocompatibility. In addition, materials based on CS also have immune stimulation and antibacterial performance, and are often used in fields such as wound healing, hemostasis, tissue engineering, and medical textiles. Nonetheless, CS suffers from poor electrospinning performance and insufficient mechanical strength, often necessitating crosslinking or blending with other polymers to enhance these properties. Polyvinyl alcohol (PVA), a water-soluble polymer, is extensively employed in the biomedical field, particularly in tissue engineering and wound dressings, owing to its favorable biocompatibility and biodegradability. PVA also has excellent film-forming and fiber forming properties, making it widely used in the field of electrospinning. Glycerol (GL) is a transparent, colorless, odorless, viscous, and hygroscopic liquid produced by the hydrolysis of triGLcerides. It is often used as a wetting agent in the food industry (plasticizer, stabilizer, and emulsifier) and cosmetic formulations.
To meet the requirements of high hydrophilicity and antibacterial properties for medical trauma dressings, PVA/CS/GL nanofiber membranes were prepared by using CS, polyvinyl alcohol (PVA), and GL as raw materials through electrospinning technology. The morphology and structure of the nanofiber membranes were characterized, and their thermal stability, hydrophilicity, swelling degree, mechanical properties, and antibacterial properties were analyzed. The results indicated that the PVA/CS/GL nanofiber membrane exhibited optimal overall performance when the mass fraction of GL was set at 3%, featuring a well-structured network and uniform fiber diameter. The addition of GL improved the poor hydrophilicity and low mechanical strength of chitosan based nanofiber membranes. After adding GL with a mass fraction of 3%, the contact angle of the nanofiber membrane decreased from 53.3 ° to 25.3 °, and the equilibrium swelling rate in PBS buffer increased from 239.5% to 332.1%. The tensile strength and elongation at break increased from 2.68 MPa and 8.2% to 5.83 MPa and 17.9%, respectively. Antibacterial experiments showed that the antibacterial rates of PVA/CS/GL nanofiber membranes against Escherichia coli and Staphylococcus aureus were 94.39% and 89.65%, respectively, showing good antibacterial performance. Therefore, the PVA/CS/GL nanofiber membrane has potential application value in medical trauma dressings. 

Key words: chitosan, polyvinyl alcohol, glycerin, nanofiber membranes, hydrophilic, swollen