Freeze-dried crosslinked anionic hydrogels composed of poly(vinyl pyrrolidone) and poly(vinyl alcohol): synthesis, characterization and degradability performance

Abstract

Purpose: Poly(vinyl pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) has enticed significant research interest and are acknowledged among the principal volume of synthetic polymers that have been fabricated globally for nearly one century. This is as a result of their excellent attributes which dictated its wide-ranging usage in a range of applications, chiefly in medical field. The investigation is aimed at preparing PVP/PVA hydrogels using freeze drying technique for its characterization and accessing the biodegradability of the prepared hydrogel. Methods: Scanning electron microscopy and Fourier transform infrared spectroscopy were employed for the description of the morphology and chemical composition of the prepared hydrogels. More characterization studies were implemented by measurement of apparent density, porosity, swelling ratio and crystallinity of the fabricated hydrogel with the use of X-ray diffractometer (XRD). The biodegradability of the prepared hydrogel was also carried out in vitro in phosphate buffered saline. Results: As the PVP content increased the percentage of porosities from 45.00 ± 1.00% to 81.80 ± 0.20%, which was also accompanied by an increase in density. The prepared hydrogel showed increase in swelling ratio as the PVP content increased, the highest swelling ratio was found in PP4 with 95.58% with the least swelling time of 4 minutes. Conclusions: To sum it up, PVP plays a role as network and performance regulator in this sort of anisotropic hydrogels. This investigation offers a fascinating means of regulating morphology and general characteristics of the PVA-based anisotropic hydrogels.