EVALUATION OF CHITOSAN/CaSO4/PLATELET-RICH PLASMA MICROSPHERE COMPOSITES AS ALVEOLUS OSTEOGENESIS MATERIAL

Periodontal disease is the manifestation of serious bacteria infection that may extend to the gingival, periodontal ligaments, and alveolus bone. One commonly administrated treatment is the debridement therapy with the removal of infected area including the soft and hard lesion tissues. In some critical case, osteogenetic materials are being filled into the defective voids to improve the regeneration of slow-growing bony tissues. In attempt to improve bone regeneration, chitosan microsphere composites embedded with two osteogenesis beneficial ingredients, CaSO 4 and platelet-rich plasma (PRP), were fabricated by using a high voltage electrostatic field system. Three groups, chitosan/ CaSO 4 microspheres (Group A), chitosan/ CaSO 4 microspheres mixed with thrombin (Group B), and chitosan/ CaSO 4/PRP microspheres mixed with thrombin (Group C) were prepared. And, these chitosan-based composites were evaluated together with a control group in pig oral model for the bone regeneration study. The chitosan/ CaSO 4/PRP microsphere composites, exhibiting good sphericity, were in the range of 457.5 ± 59.3 μ m in diameter. Defects filled with Group B and Group C showed increases in new bone formation along with fibrous tissue regeneration as compared to that filled with Group A. The Masson's Trichrome stain observations suggested more abundant presence of fibrous collagen matrices around the defects after implanted with Group B over that of Group C microsphere composites. The preparation of chitosan/ CaSO 4-based microspheres was straight forward by using high voltage electrostatic field system. Furthermore, Chitosan/ CaSO 4-based microspheres with thrombin could be used successfully in regenerating new bone around the alveolus bone area.

CHITOSAN IN APPLICATIONS OF BIOMEDICAL DEVICES

Chitosan is a natural polysaccharide with great potential for biomedical applications due to its biocompatibility, biodegradable capability, and nontoxicity. Various techniques used for preparing chitosan microspheres/membranes and evaluations of these fabrications have also been reviewed. The hydrophilicity of chitosan provides unique characteristics of hydrogel formation with the acidic media and may entrap the drug content inside of the matrix for controlled release. In order to improve upon the scope of preparation of chitosan microspheres, we had successfully employed and incorporated a high-voltage system into the direct pumping injection process. The wide range of drug release profiles could be attributed to the surface characteristics, porosities, and various structures of chitosan microspheres upon treatment with Na5P3O10/NaOH solutions of various volume ratios. We also demonstrated that with the addition of chitosan/β-TCP microspheres as a constituent into the PMMA cement significantly decreases the curing peak temperature and increases the setting time. The excellent gelforming property of chitosan offers another biomedical application in membrane separation fields. Chitosan membranes were prepared by a thermal induced phase separation method, following treatment with nontoxic NaOH gelating and Na5P3O10, Na2SO3 crosslinking agents. In order to further improve the mechanical strength and biocompatibility and to expand the potential of chitosan GTR membranes in periodontal applications, various chitosan membranes incorporating with negatively charged alginate, bioactive tricalcium phosphate, and platelet rich plasma, respectively, were also prepared and characterized. Moreover, we had also utilized chitosan, which with good blood-clotting, cheap, and easy preparation characteristics, as the raw material to prepare rapid clotting wound dressing and tooth plug.