Preparation Of Poly(Vinyl Alcohol) Porous Hydrogel With High Strength And Well Ciprofloxacin Release Efficiency

The research is concentrated on PVA system and the study content includes C ip release behavior in porous PVA scaffolds and porous PVA hydrogels with high strength.Firstly,the release behavior of PVA/C ip scaffolds and PVA/PEG/C ip scaffolds are studied in the experiment and the release efficiency impproved greatly when PEG added into PVA/C ip system.Then,a series of porous PVA hydrogels with high strength prepared by combining freeze-thaw and freeze-dry method(in liquid nitrogen).Major work includes:Polymer scaffolds used in drug release are always so weak that they will be eroded/degraded in drug release process.So,the porous scaffolds fabricated in the research is based on PVA system,the PVA scaffolds show excellent mechanical property(10.5 MPa for PVA scaffold when the solution concentration is 18 wt%)but with poor release efficiency(54.4% fo r PVA scaffold stemming from 18 wt% concentration solution).PEG is added to PVA/C ip system and the release efficiency of the scaffolds improved obviously,all the PVA/PEG/C ip scaffolds present well release property(release efficiency above 90%)but with little decreasing for mechanical property compared with PVA sca ffolds.However,the C ip release of scaffolds in the study is incomplete,the PVA/PEG/C ip scaffolds prepared from 6 wt% solution concentration solve the problem effectively.The release efficiency is nearly 100%,but the extent of errosion of the scaffolds are seriously.The matter is settled by freeze-thaw method and the release efficiency of PVA/PEG/C ip scaffolds maintain well.Finally,the research explore the reason of C ip release improvement from the inner morphologies of scaffolds,the interaction of polymer and polymer,the interaction of polymer and C ip,the C ip crystal transfer.Porous PVA hydrogels with high strength could be fabricated by freeze-dry method and freeze-thaw method both.The PVA hydrogel prepared by 3 freeze-thaw cycles(freeze for 16 h and thaw for 8 h)from 14 wt% concentration solution show the best mechanical property(5.74 MPa).The inner morphologies,water content,mechanical property of PVA hydrogels fabricated by these two methods are similar with some human cartilages.