Hydrogels based on poly(methacrylic acid) and nanocellulose with potential application in dental treatments

Abstract

pH sensitive hydrogels, such as hydrogels based on poly(methacrylic acid) (PMAA), are tremendous materials with great properties due to which they have application in many fields, such as: targeted drug delivery, tissue engineering, as contact lenses etc. Hydrogels based on PMAA are non-toxic, biocompatible and able to absorb and retain huge amount of water. These hydrogels are widely used for targeted drug delivery due to their specific pH swelling behavior which enable drug release in environments with pH values higher than pKa(PMAA). However, poor mechanical properties of hydrogels based on PMAA often limit their application. In order to overcome this limitation, green approach is used in present study. Namely, nanocellulose (NC) extracted from wood waste material is added to PMAA due to NC non-toxicity, biocompatibility, biodegradability and great mechanical properties (which is used for improvement of hydrogels mechanical characteristics). Further improvement of hydrogels based on PMAA and NC is achieved by adding carboxymethyl cellulose (CMC). CMC is non-toxic, biocompatible, biodegradable, pH-sensitive derivate of cellulose widely used in drug delivery systems. Drug delivery system prepared in that way can enable controlled release of drug (such as lidocaine hydrochloride (Lid)) for prolonged period of time and therefore, reduce the number of acquired drug dosages which further lead to safe and efficient drug application. Therefore, Lid is encapsulated in hydrogels based on PMAA, NC and CMC (PM/NC-Lid). Lid is local anesthetic often used in dental treatment and it is usually administrated by injection, which is painful, unpleasant and treatment is often required several dosages. These limitations can be overcome by applying PM/NC-Lid hydrogels as buccal patches for controlled release of lidocaine hydrochloride. Present study describes green synthesis and characterization of PM/NC-Lid hydrogels (using the Fourier Transform Infrared spectroscopy (FT-IR), the Scanning Electron Microscopy (SEM) and the single compression tests). Also, PM/NC-Lid swelling behavior and Lid controlled release from PM/NC-Lid hydrogels is investigated depending on the variable synthesis parameter (NC wt%) in simulated buccal environment. Results presented in this study show that PM/NC-Lid hydrogels are promising materials for controlled release of anesthetic drugs and for potential application as buccal patches in dental treatments.