The Effect of β-Glycerophosphate Crosslinking on Chitosan Cytotoxicity and Properties of Hydrogels for Vaginal Application

Abstract

Mucoadhesive gelling systems based on chitosan and chitosan/β-glycerophosphate (β-GP) were developed in order to increase clotrimazole residence time in the vaginal cavity. Ex vivo mucoadhesiveness using porcine vaginal mucosa followed with mechanical, viscoelastic, and swelling properties of prepared hydrogels were evaluated. Drug-free, sterile, unmodified, and β-GP crosslinked chitosan were investigated for the in vitro cytotoxicity in CRL 2616 human vaginal mucosa cells using MTT assay, fluorescent microscopy, and flow cytometry analysis. Chitosan/β-GP hydrogels exhibited pseudoplastic and thixotropic properties. Ionic interaction between β-GP and chitosan improved mechanical properties of hydrogels in terms of hardness, cohesiveness, and compressibility. The hydrogels' ability to interact with porcine vaginal mucosa (measured as force of detachment and work of adhesion) was comparable to those obtained with reference mucoadhesive gel Replens™. Surprisingly, greater mucoadhesive properties were noticed for chitosan/β-GP hydrogels. The cytotoxic effect of unmodified and β-GP crosslinked chitosan was hardly affected by chitosan molecular weight, exhibited mainly through inducing apoptosis, and was found to be significantly lower in the presence of chitosan/β-GP. Furthermore, the higher amount of β-GP was used to crosslink chitosan, the lower cytotoxic effect was observed.

Novel Spray Dried Glycerol 2-Phosphate Cross-Linked Chitosan Microparticulate Vaginal Delivery System—Development, Characterization and Cytotoxicity Studies

“…Based on the plotted trend line (Figure 3A), it was also noticed that unmodified chitosan and βGP/chitosan microparticles possessed comparable values ( p > 0.05) of F max . The obtained data is in agreement with results previously reported by our group, indicating that βGP modification of chitosan in semi-solid drug carriers maintained polymers’ ability to interact with mucosal tissue [35]. Nonetheless, the obtained W ad values were found to demonstrate a downward trend (Figure 3B) with raising the amount of ion cross-linker in chitosan microparticles.…”

“…In addition, the obtained results demonstrated comparable viability of VK2/E6E7 cells within exposures to unmodified and βGP cross-linked chitosan microparticles. Interestingly, the above findings did not correspond with the cytotoxicity studies previously reported by our group in which lesser degrees of cytotoxicity had been noticed in VK2/E6E7 incubated with solutions of chitosan cross-linked with βGP (prepared by simple dissolution of the polymer in acetate buffer without further processing) [35], which might indicate that the applied spray drying process could have influenced the cytotoxicity profile of βGP/chitosan.…”

“…Simple CLO dispersion in the release medium (1.0% ( w / v )) was used as a control. A USP II dissolution tester (Agilent 708-DS, Agilent Technologies, Cary, NC, USA) equipped with mini paddles and mini vessels (250 mL) was applied to measure the CLO release from the drug reservoir [35]. The dissolution medium—acetic buffer pH 4.5 [57] with addition of 1.0% Cremophor EL—was maintained at 37 °C ± 0.5 °C and the rotation speed was 75 rpm.…”

“…Recently, chitosan/βGP material has attracted considerable attention as a promising tool for a variety of applications, such as local drug carriers or injectable delivery systems for tissue engineering [33,34]. In addition, data previously published by our group showed that ionic interaction between βGP and chitosan improved mechanical properties of hydrogels and enabled prolonged drug release profile [35,36]. …”

Effect of Dual Releasing of β-glycerophosphate and Dexamethasone from Ti Nanostructured Surface for Using in Orthopedic Applications

“…The viability of more than 85% cells in comparison with control group proved the biocompatible performance of the specimen. Vacanti et al [39] and Szymanska et al [40] demonstrated before that DEX and GP exhibit good biocompatibility in controlled one agent releasing vehicles, respectively. At the present research, it is shown that the dual releasing system of GP and DEX contain PVA coating enhanced biological properties of the anodized Ti.…”