Evaluation of tetracycline containing chitosan hydrogels as potential dual action bio-active restorative materials capable of wound healing: in vitro approach

Wound healing is a specific biological process related to the general phenomenon of growth and tissue regeneration. Wound healing progresses through a series of interdependent and overlapping stages in which a variety of cellular and matrix components act together to reestablish the integrity of damaged tissue and replacement of lost tissue. The objectives of this study was to evaluate the novel chitosan based functional drug delivery systems which can be successfully incorporated into "dual action bioactive restorative materials" capable to induce an improved wound healing prototype in-vitro. The system contained a common antibiotic such as tetracycline, krill oil as an antioxidant, hydroxyapatite as a molecular bone scaffold, which is naturally present in bone and is reported to be successfully used in promoting bone integration when implanted as well as promoting healing. The hydrogels were prepared as previously reported. The bioadhesive capacity of the materials in the 2 separate "in vitro" systems were tested and quantified. Additional action of chitosan: vitamin C pre-complex was investigated and it was found that favorable synergistic effect of free radical build-in defense mechanism of the new functional materials. Additional action of chitosan: vitamin C precomplex was investigated and it was found that favorable synergistic effect of free radical build-in defense mechanism of the new functional materials increased dentin bond strength and sustainable bioadhesion and therefor act as a "proof of concept" for the functional multi-dimensional restorative materials with potential application in wound healing in vitro. A steady slow release of tetracycline, while maintaining antibiotic effects against the tested bacteria for at least 10 days, was shown from designer chitosan-therapeutic agent hydrogels. Based on our results, we can conclude that the chitosanantioxidant containing hydrogels are a suitable carrier for tetracycline to be slow-released. Within the limitations of the study design chitosan based hydrogels are suitable materials for functional restorative and wound healing applications in vitro. However, future investigations are necessary to validate this hypothesis. The addition of antioxidants to the tetracycline containing prototype delivery system had a beneficial effect on the design of the hydrogel by slowing down the release of tetracycline and thereby enabling a sustainable antifungal activity over time.