Preparation Of Photocrosslinking PVA-SBQ/GMHA Nanofibers And Hydrogels And Their Drug Loading Studies

Hyaluronic acid is a kind of polysaccharide biopolymer with good biocompatibility and biodegradability and is widely used in various biomedical fields.However,its application has been limited due to the strong hydrophilic,too large viscoelastic and rapid degradation.The research on the modification of hyaluronic acid mainly focuses on chemical crosslinking,and rarely involves photo-crosslinking.In this paper,the hyaluronic acid was modified by glycidyl methacrylate to prepare hyaluronic acid derivative(GMHA)containing double bond.Then PVA-SBQ/GMHA nanofibers and hydrogels were respectively prepared by UV photocrosslinking,which can slow down the degradation of hyaluronic acid and improve the biocompatibility of PVA-SBQ.The research is divided into two parts:(1)The PVA-SBQ/GMHA nanofibers were prepared by photocrosslinking.The effects of different illumination time,temperatures and pHs on the swelling properties of PVA-SBQ/GMHA fibers were investigated respectively.The swelling ratio of PVA-SBQ/GMHA fibers decreased with increasing temperature.The swelling degree at pH 7.2 was higher than that at pH 2.2.The effects of different drug loadings,different temperatures and different pHs on the release properties of drug-loaded nanofibers were studied.The 1%drug loaded fiber membranes showed good performance and achieved controlled drug release.The cumulative drug release rate of fiber membranes decreased with increasing temperature and the release rate at pH 7.2 was greater than that at pH 2.2.The thermal stability of PVA-SBQ,PVA-SBQ/GMHA and 1%PVA-SBQ/GMHA fiber membrane were studied.The results showed that the three samples had good thermal stability.(2)The PVA-SBQ/GMHA hydrogels with different mass ratios and different illumination time were prepared by UV cross-linking method.The SEM results showed that the obtained gel had porous three-dimensional network structure due to the cross-linking,and GMHA:PVA-SBQ=1:3 hydrogel morphology was best.The swelling properties of PVA-SBQ/GMHA hydrogels in water were studied at different mass ratios,temperature and pH.The results showed that the swelling ratio of PVA-SBQ/GMHA hydrogels decreased with increasing temperature,swelling ratio at pH 7.2 was greater than that at pH 2.2 in buffer solution.The drug loading and drug release properties of PVA-SBQ/GMHA hydrogels were investigated.The accumulation drug release rate of PVA-SBQ/GMHA hydrogel was decreased with temperature rise.Release rate of pH 7.2 was greater than that of pH 2.2.The thermal stability analysis indicated that HA content has important effect on the thermal stability of the hydrogel.But the drug loading had little effect on the their thermal stability.