[Experimental study on adipose-derived stem cells combined with acellular dermal matrix particles for vocal fold injection].

Objective To explore the feasibility of adipose-derived stem cells （ASC） combined with micronized acellular dermal matrix （MADM） for vocal cord injection. Methods The adipose-deprived stem cells were harvested from rabbit adipose tissue in vitro. The 3rd generation of ASC was labeled with DiI （1, 1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate） and cultured with MADM to form a complex. The adhesion of ASC to MADM was observed by fluorescence microscope and electron microscope.The proliferation of ASC on MADM was evaluated by 3-（4, 5-dimethylthizazol-2-yl）-5-（ 3-carboxy methoxyphenyl）-2-（4-sulfonyl ）-2H- tetrazolium, inner salt （MTS）. Three days after the culture, the complex was mixed with appropriate amount of collagen, and then injected into the unilateral vocal cord of the rabbit. The animals were sacrificed 2, 4, 8 weeks after injection, the survival time and distribution of ASC in vocal fold were tested, and the responses of vocal cord to ASC-MADM and the degradation of MADM were observed. Results The ASC adhered to MADM and grew well （P ＜0.05 or ＜0.01 ）, showing good compatibility with MADM in vocal cord tissue. The complex of ASC-MADM could be injected into the rabbit vocal cords, while no adverse reactions was observed in the vocal cord by endoscope, frozen section and HE staining. ASC could survive for 8 weeks in vocal cords, and no inflammatory cell infiltration was observed. Conclusions MADM is an ideal scaffold material and shows perfect compatibility with ASC which can adhere and proliferate well on it. The complex of ASC-MADM can be injected into the vocal cord and can survive. There is no adverse reaction in vocal cords. Key words: Stem cell transplantation; Adipocytes; Tissue engineering; Vocal cords; Rabbits