Fabrication and In-vitro characterization of chitosan derivative and strontium apatite composite sheets for periodontal tissue engineering

BACKGROUND: Periodontal regeneration is defined as regeneration of the tooth-supporting tissues including cementum, periodontal ligament and alveolar bone. A potential tissue-engineering (TE) approach to periodontal regeneration involves the incorporation of progenitor cells and instructive messages in a prefabricated three dimensional construct and subsequent implantation of the construct into the defect site. The third generation guided tissue regeneration (GTR) membranes are based on the concept of TE. Biomaterials consist of biodegradable polymers and bioactive ceramics, are suitable for regenerative medicine. Chitosan, a biodegradable natural polymer and it possess excellent biological properties such as biocompatibility, antibacterial effect, and rapid healing capacity. It has several limitations including poor solubility under physiological conditions, to overcome these limitations, we focused on Chitosan derivative. Strontium, a trace element in the natural bones, can be substituted for calcium in hydroxyapatite, producing beneficial effects on bone, including stimulation of osteoblast differentiation, inhibition of osteoclast formation and bone resorption in-vitro. It also showed an excellent healing capacity. So we incorporating strontium in synthesized hydroxyapatite. Thus in this study an attempt is being made to fabricate new generation GTR membrane for periodontal tissue engineering application. AIM OF THIS STUDY: The aim of this study was to fabricate GTR membrane of chitosan derivative and strontium apatite of varying concentration via freeze drying technique and comparing their in-vitro properties. MATERIALS AND METHODS: GTR membranes made of chitosan derivative and strontium apatite of varying concentration via freeze drying technique and comparing their in-vitro properties. Morphological Properties analysed using scanning electron microscope (SEM). The mechanical properties such as tensile strength, elongation break and tear strength of samples were determined by using universal testing machine. Average membrane thickness was measured using thickness gauge. Chemical analysis are analysed using Fourier transformation infrared (FTIR)Spectroscopy In-vitro degradation test of the scaffold were conducted by incubating the membrane in PBS at 37oC for 1, 5, 9, 13, 17, 21, 26 and 29days. Invitro bioactivity test of the scaffold were conducted by incubating the membrane in SBF at 37oC for 3 and 7 days. Cytotoxicity assessment are observed using L-929 mouse fibroblasts. RESULT: All the fabricated scaffolds were highly porous and had interconnected pore structure. The mechanical properties of fabricated membranes observed. Among these, chitosan derivative- strontium apatite membrane (7.5 mg and 10 mg) possess increased thickness (mm) [0.50±0.02], chitosan derivative possess increased tensile strength and chitosan derivative- strontium apatite (7.5mg) exhibited highest tear strength (MPa) [0.65±0.05]. Evaluating the chemical stability of the fabricated membrane by FTIR, results clearly indicate the strong bonding between chitosan derivative-strontium apatite composite membrane. For degradation analysis and invitro bioactivity composite containing strontium apatite experienced higher weight loss. In cell culture composite membrane showed positive response to mouse fibroblasts L929 cell attachment, here chitosan derivative-strontium apatite (7.5mg) (85.69%) exhibited enhanced viability than chitosan derivative. CONCLUSION: From the observation of the study it was concluded that chitosan derivative - strontium apatite composite membrane could be suitable for use as a GTR membrane. Further studies are needed for chitosan derivative -strontium apatite composite membrane for clinical use.