Constructing a tissue-engineered dental root by seeding dental papilla cells into poly(lactic-co-glycolic acid)/sodium alginate hydrogel / 中国组织工程研究

ABSTRACT

BACKGROUND:Studies addressing reconstruction of tooth tissue engineering have shown that tooth structure can be constructed using tissue engineering technology. Tooth root and its periodontal attachment are critical for tooth survival and functions, based on which, whether we can target root tissues with simple structure for tissue engineering construction by bypassing a complex dental tissue engineering concept with the structural integrity? OBJECTIVE:To construct a tissue-engineered dental root by seeding dental papil a cells, as seed cells, into poly(lactic-co-glycolic acid)/sodium alginate hydrogel. METHODS:Rabbit dental papil a cells were isolated and cultured. The cells were then mixed with 1%sodium alginate hydrogel at a final density of 6×109/L. The cellsuspension was seeded into a poly(lactic-co-glycolic acid) scaffold with predetermined shape of human tooth and solidified with calcium chloride. Final y, the cel-scaffold composites were subcutaneously implanted into the back of nude mice. The specimens were harvested after 4 and 8 weeks respectively and processed for gross inspection, X-ray and CT examination and histological observation. RESULTS AND CONCLUSION:The newly formed tissue kept the original shape of human dental root 4 and 8 weeks post-implantation. After 4 weeks of implantation, the specimen density was low;the root implants appeared to be incompletely mineralized, alginate hydrogels were degraded, but the copolymer scaffold was not degraded;a number of dentin-like structure appeared, and a fibrous membrane structure was visible on the surface of specimens paral el to the root surface, but the structure was not continuous, and no pulp cavity formed. After 8 weeks, the newly formed tissue was highly mineralized close to root tissue of the nature tooth;the copolymer scaffold was mostly degraded;specimens appeared to have a large number of mature dentin-like structure, and form continuous fibers membrane on the surface paral el to the root surface, below which, cementum-like structure formed. Artificial dental root with biological y similar structures of human dental roots can be constructed using the method of tissue engineering.