Preparation Of Polyvinyl Alcohol Composite Hydrogels And Study On Their Sustained Release Properties

Because hydrogel is a crosslinked polymer network structure,it has the ability to absorb and retain water.It can be used as a good drug carrier and can play a specific function in practical applications.In a controlled release system,the drug carrier requires It has acid resistance,enzyme resistance and sustained release properties,and hydrogels have exactly these characteristics.Polyvinyl alcohol,polyvinylpyrrolidone,and cationic starch are among the raw materials in fine chemicals.They have a wide range of uses,low prices,high biocompatibility,no cytotoxicity,and high research value.There are many reports on the research of hydrogels,but the study of mixing the three to prepare hydrogels has not been found.Therefore,this study aims to impart the characteristics of cationic starch to the hydrogels and make the hydrogels It has certain positive ions,which enhances the bacteriostasis.At the same time,it contains anion and cationic drugs and has p H sensitivity,which lays a certain foundation for its application as a drug carrier or wound dressing.In this study,PVA/PVP hydrogel and PVA/PVP/CS hydrogel were prepared using polyvinyl alcohol,polyvinylpyrrolidone,and cationic starch as raw materials.The structure and morphology of the hydrogel were observed,and the hydrogel was analyzed.The swelling performance of the hydrogel was affected by various factors.The release of the hydrogel-loaded model drug and the detection of the antibacterial effect of the hydrogel itself were studied.The main results of the study are as follows:(1)The construction of hydrogels is mainly cross-linked by hydrogen bonding.FT-IR,XRD and SEM characterization showed that both PVA/PVP hydrogels and PVA/PVP/CS hydrogels were physical cross-linked hydrogels.PVA/PVP hydrogels mainly form hydrogen bond binding sites between a large number of hydroxyl groups of PVA and a large number of carbonyl groups of PVP;PVA/PVP/CS hydrogel is composed of a large number of hydroxyl groups in PVA and CS and the carbonyl group between the carbonyl group and PVP to form hydrogen bond.(2)The structure and equilibrium swelling rate of hydrogels are changed by the proportion and variety of raw materials.The structure of hydrogel loosens with the increase of PVP and CS,and the crystallinity of PVA decreases.The equilibrium swelling rate of hydrogel increased with the increase of PVP and CS content: PPK90-4 > PPK90-3 > PPK90-2 >PPK90-1;PPCS-5 > PPCS-4 >PPCS-3 >PPCS-2 > PPCS-1.The equilibrium swelling rate of hydrogel increased with the increase of molecular weight of PVP: PPK90 > PPK30 > PPK17 > PVA.(3)The number of freeze-thaw cycles has a certain influence on the equilibrium swelling rate and water content of PVA/PVP and PVA/PVP/CS hydrogels.The swelling properties of PVA/PVP and PVA/PVP/CS hydrogels varied with different temperature,p H and Na Cl.(4)hydrogel has a certain ability of drug sustained release.The drug release capacity of PVA/PVP and PVA/PVP/CS hydrogels was tested by loading model drug rhodamine B.The drug release capacity of PVA/PVP hydrogels in different p H releasing media was alkaline > neutral > acid.Drug releasing capacity of PVA/PVP/CS hydrogels in different p H releasing media: neutral > alkaline > acid.The antibacterial experiment showed that the PVA/PVP/CS hydrogel added with CS had certain antibacterial effect on escherichia coli and staphylococcus aureus.