Insights into Functional Tetracycline/Antioxidant Containing Chitosan Hydrogels as Potential Bio-Active Restorative Materials: Structure, Function and Antimicrobial Activity

Abstract

Substantial data are available in the literature on the role of Reactive Oxygen Opecies (ROS) and antioxidants in disorders such as the inammatory and in chronic immune mediated conditions such as rheumatoid arthritis. However, remarkably little information is available on the periodontal diseases, which show many of the pathological features of other chronic inammatory diseases. The periodontal tissues also provide an ideal medium within which to study mechanisms of ROS mediated tissue damage and of antioxidant defense in response to bacterial colonization, through the non-invasive collection of GCF. Bio-adhesive polymers appear to be particularly attractive for the development of alternative etches free dentin bonding system with an added advantage of additional therapeutic delivery systems to improve intradental administration of therapeutic and prophylactic agents if necessary. Chitosan, which is a biologically safe biopolymer, has been proposed as a bio-adhesive polymer and are of continuous interest to us due to their unique properties and exibility in broad range of oral applications reported by others and us recently. The objectives of this study is to evaluate the novel chitosan based functional drug delivery systems which can be successfully incorporated into “dual action bioactive restorative materials” containing common antibiotic such as erythromycin, krill oil, aloe and aspirin as commonly used antioxidant species.\rMethods:\rThe novel hydrogels will be investigated with respect to the antioxidant capacity and drug release capacity of the tetracycline as well as erythromycin from the designer drug delivery system, the use of SEM imaging for the characterization of the surfaces and reactive features of novel materials with antimicrobial potential as well as use of the newly designed materials as an effective adhesive restorative materials.\rResults:\r A continuous release of erythromycin, while maintaining antibiotic effects against the tested bacteria, for at least 24 hours was shown from designer chitosan-antioxidant hydrogels. The increase antioxidant capacity of the designer material, signicant antimicrobial capacity as well as adhesive dentine bond strength make the chitosan-containing restorative materials suitable and potentially advantageous materials for restorative and periodontal applications\rin-vitro\r. The addition of antioxidants to the functionalized restorative material acts as a alternative free radical defense mechanism and therefor increases the shear bond strength teeth by managing the excess of free radicals produced during common restorative procedure. Future investigations are necessary to validate this hypothesis