PVA, as a synthetic polymer, has not exhibited toxicity or allergic reactions during its use. Numerous toxicological studies have shown that PVA hydrogels have low toxicity to cells and tissues, providing strong support for their safety and widespread application in the medical field. The non-toxicity of PVA hydrogels makes them ideal implant materials and drug delivery carriers, offering a safer and more reliable option while avoiding the adverse reactions that may arise from traditional chemical materials. In medical applications, polyvinyl alcohol microparticles have been approved by the FDA for use as embolic particles. In biomedical engineering research, polyvinyl alcohol has been studied for use as a material for artificial cartilage, orthopedic medical applications, and artificial transplanted blood vessels.
1.ophthalmology
PVA possesses excellent film-forming and water-retention properties, and does not cause stickiness or blurred vision, leading to its early use in eye drops. In recent years, PVA hydrogels prepared via freeze-thaw processes have been widely applied in ophthalmology, such as in contact lenses and artificial corneas. PVA hydrogel contact lenses significantly improve wearing comfort due to their high oxygen permeability, resistance to protein deposition, and abrasion resistance. As early as 1990, high-water-content, high-oxygen-permeability PVA contact lenses were successfully prepared, and their biocompatibility was verified. Furthermore, the application of nano-hydroxyapatite (HA) composites with PVA in artificial corneas can enhance biocompatibility, demonstrating promising clinical application potential.
2.wound dressing
Ideal wound dressings should possess properties such as absorbing exudate, moisturizing the wound, resisting infection, being breathable, having excellent mechanical properties, and promoting cell growth. PVA hydrogels can provide a moist healing barrier, absorb exudate, and can be processed into various shapes, showing broad application prospects. However, pure PVA hydrogels are prone to swelling after absorbing liquid, and their elasticity and mechanical properties are poor; therefore, they are often used in combination with other polymers. Studies have shown that composite PVA hydrogels, such as PVA-HA, PVA-chitosan, PVA-alginate, and PVA-dextran, can significantly improve swelling performance, protein adsorption, softness, and antibacterial properties, promote wound healing, and meet mechanical requirements, making them high-performance wound dressings.
3.Artificial articular cartilage
In selecting materials for artificial articular cartilage, the ideal material needs to possess elasticity and mechanical properties similar to natural cartilage. While silicone rubber has good elasticity, it has poor wear resistance and is prone to aging and failure; polyurethane, although elastic, has hydrolysis products with potential biotoxicity. PVA hydrogel, due to its porous structure similar to natural cartilage, is considered one of the more ideal alternative materials. Researchers injected 10%–20% PVA solution into a stainless steel fiber mold with ventilation holes, and then used pressure to allow the solution to penetrate into the fiber mesh. After multiple freeze-thaw cycles and vacuum dehydration, PVA hydrogels with a water content of 40%–86.5% were obtained. Bone cement was then used for bonding, achieving a strong bond between the artificial cartilage component and the stainless steel substrate. A four-month animal articular cartilage repair experiment showed no inflammatory response after hydrogel implantation. In addition, some scholars have prepared PVA aerogels through cyclic freeze-thaw and pre-stretching processes, and then treated them in different salt solutions to form PVA hydrogels. The hydrogels have a tensile strength of 41.0 MPa and an elongation at break of up to 228.0%. They also have antibacterial, antiseptic, and free radical scavenging properties, showing good prospects for development in the field of artificial cartilage.
