OBJECTIVETo evaluate the feasibility of the tissue engineered submandibular gland constructed in vivo based on submandibular gland cells and silk fibroin-chitosan (SFCS).

METHODSSubmandibular gland cells were obtained and purified. The second generation cells labeled by 5'-BrdU were seeded on SFCS(5 mm × 5 mm × 5 mm). Submandibular gland cells seeded on SFCS was implanted beneath the skin on the back. At 3, 7, 14 d post-implantation, implant sites were examined local and systemic responses. After paraffin embedding, serial sections 6 mm thick were cut and stained with either hematoxylin and eosin or brdu tissue stain for immunohistochemical studies and examined the responses of tissue. Scanning electron microscope was used to observe the growth behavior submandibular gland cells on SFCS scaffolds.

RESULTSGeneral observation: at the 3, 7, 14 d after in vivo implantation, capsule formed in the surface of insert. Histological observation: in experimental group, submandibular gland cells proliferate on the SFCS scaffold fused to form unit 14 d after implantation. Brdu immunohistochemical observation: the results of labelled cells were positive by immunohistochemical method at each time point. Cytokeratin-8 (CK-8) immunohistochemical observation: the results of labelled cells were positive by immunohistochemical method at each time point. With time, the positive cells gradually increased. Scanning electron microscope: the shape of the SFCS scaffold was mesh. At earlier, submandibular gland cells presence in disorder at attach to the SFCS. At the 14 d submandibular gland cells proliferate on the SFCS scaffold and form functional unit.

CONCLUSIONSSuch constructed tissue engineered submandibular gland based on submandibular gland cells and SFCS is promising.