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This review introduces a brief description on the featured properties of polyvinyl alcohol based on hydrogel dressings. During past ten years many new artificial polymeric dressings have been developed, which meet requirements of wound healing. This review mainly focuses on one representative of ideal polymeric wound dressing membranes, polyvinyl alcohol based hydrogel dressings. But as the hydrogels with single component have low mechanical strength, recent trends have offered composite hydrogel membranes to achieve the ideal wound dressing requirements.
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Bandages , Hydrogels , Polyvinyl Alcohol , Tensile Strength , Wound HealingABSTRACT
The polymer composites based on Polyvinyl alcohol loaded with different concentrations of commercial curcumin were prepared to be applied forcontrolled release drug delivery system to overcome the growth promotion of tumor cells. The prepared composites were subjected to drug release in aqueous media at room temperature. It was found that the amount of the released curcumin changed according to different pH media and the concentration of the loaded drug onto the polymer carrier. The diffusion coefficient of the released curcumin from the prepared composites was found to be 2.739X10-2, 1.638X10-2, and 5.777X10-4 in basic, acidic and neutral solution respectively according to Higuch's equation. The results of the in/vitro cytotoxic activity of the released curcumin showed sustained antiproliferative potency up to 30 % growth inhibition against the human liver cancer cell line (HEPG2) which extended to 25 days, to overcome hepatocarcinoma.
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Objective To study the mechanical properties of PVP/PVA composite hydrogel and its interaction principle based on the molecular dynamics (MD) theory. Methods MD simulation was applied to investigate mechanical properties and radial distribution functions of PVP, PVA and their mixed system PVP/PVA. Results Compared with the pure PVP, mechanical properties of PVP/PVA were significantly improved, and not affected by temperature. The interaction between PVA and PVP was expected to occur through the interchain hydrogen bonding between the oxygen atom of PVP and the hydroxyl group of PVA. Conclusions MD method revealed the interaction mechanism of PVP/PVA hydrogel at molecular microscopic level and proved it better than pure PVP. Meanwhile, its mechanical properties were stable at different environment temperatures. These results provide a reliable theoretical research method for studying the fabrication process of hydrogel prosthesis in clinic and its mechanical properties.
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[Objective]To investigate the feasibility of the fabrication of tissue-engineered anterior cruciate ligament(ACL)in vitro by studying biocompatibility and mechanical property of the braided polyvinyl alcohol(PVA)materials.[Method]Firstly,human ACL cells and NIH3T3 cells were isolated,expanded in vitro and seeded onto the surface of the braided PVA scaffold materials,the adhesion,proliferation and three-dimensional growth of cells on the scaffold were observed by SEM.Secondly,the biomechanical properties of the braided PVA scaffold materials were measured with electro-biomechanical machine.[Result]The braided PVA scaffold materials had no cytotoxicity,ACL and NIH3T3 cells adhered,grew and proliferated well both on the surface and in the holes of the braided PVA scaffold materials.The maximum load,the maximum strain and ultimate tensile stress of the braided PVA scaffold materials respectively were 169.78?9.18N,11.67?1.38% and 52.21?2.88MPa.[Conclusion]The braided PVA scaffold materials possess good biomechanical properties and biocompatibility,it may become an ideal biomaterial for fabricating tissue-engineering ACL if the biomechanical properties can be improved.
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Objective To evaluate and conpare the immediate and long-term results of bronchial artery embolization(BAE) with different embolic agents for treating bronchiectasis accompaneid by massive hemoptysis.Methods BAE was undertaken in 32 patients with hemoptysis.Particles of PVA or gelatin sponge were used separately as embolic agents.Immediate and long-term results were evaluated separately by the different embolic agents. Results BAE was taken in 32 patients with hemoptysis dividing into two groups with 16 for each group alternatively received GS or PVA.One patient had recurrence at the 3rd day of BAE.29 patients were followed up and 8 of them had recurrent hemoptysis including 7 embolized with GS,and 1 PVA.Conclusions As embolic agents to treat bronchiectasis with massive hemoptysis,the effect of PVA is better than that of GS.500 ?m PVA is the best of choice.
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A New Combination membrane was prepared by chitosan and polyvinyl alcohol (PVA).The gas permeability and water content of the membrane are all improved better than that of simple chitosan membrane.
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Objective To prepare medical chitosan microspheres used in blood lipid adsorption. Methods Medical chitosan microspheres were prepared by suspending chitosan in liquid paraffin, adding proportional glutaraldehyde as crosslinking agent and a small amount of polyvinyl alcohol(PVA) to improve its flexibility. The blood lipid adsorption v/ere studied in a dynamic way. Results The medical chitosan microspheres containing a small amount of PVA were more effective in decreasing the contents of cholesterol(CH) , triglyceride(TG) , LDL in human serum. Conclusion The chitosan microspheres obtained by adding a small amount of PVA could be used as a desirable medical microsphere in the adsorption of blood lipids.