In vitro characterization of injectable chlorhexidine‐eluting gelatin hydrogels for local treatment of periodontal infections

Abstract

AbstractInfection of the periodontal pocket presents two major challenges for drug delivery: administration into the periodontal pocket and a high fluid clearance rate in the pocket. The current study aimed to develop and study a novel gelatin‐based hydrogel system crosslinked using a carbodiimide, for delivery of chlorhexidine (CHX) directly into the periodontal pocket via injection followed by in situ gelation. The study focused on the effects of the CHX concentration on its release profile and on the hydrogel's physical, mechanical, and biological properties. CHX is a common antiseptic agent and is considered as “gold standard” in dental practice. Its release profile demonstrated 39% burst release during the initial 2 h, followed by a release rate, which decreases with time for 6 days. A mathematical model based on the two‐stage desorption theory was perfectly fitted to the experimental release profiles (R2 > 0.99). Fibroblast viability results of at least 70% were achieved after 24 and 48 h, indicating that the system is biocompatible. The non‐loaded and CHX‐loaded hydrogels were found suitable for injectability and exhibited desired gelation times of 7.5–10.6 s, that is, compatible for filling a periodontal pocket. They exhibited excellent mechanical properties, such as burst strength (sealing ability) of 233–357 mmHg, tensile modulus of 47–69 kPa, compressive modulus of 58–104 kPa, and tensile strain of 42–113%. In conclusion, the studied CHX eluting hydrogels are of high potential to be used in minor pockets as well as deep pockets and are expected to be suitable for successfully treating a wide range of periodontal infections.