[Androgen-secreting tissue construction with co-cultured rat testes somatic cells by tissue engineering technique]

To explore the feasibility of constructing androgen-secreting tissue of a certain size and shape using co-cultured somatic cells of rat testis.

Thirty male Wistar rats were castrated. model and implanted rat model were prepared by resecting bilateral testes. The suspension of mixed testes cells was cultured to obtain various somatic cells of testes and Leydig cells were collected by differential anchorage-dependent method. These two kinds of cells were seeded onto biodegradable scaffolds of polyglycolic acid (PGA) fibers and cultured in vitro. The tissue formation of cell-scaffold constructs was observed by optical microscope and electronic microscope and the level of testosterone in the supernatant was detected regularly. After 7-day culture in vitro, the 2 kinds of cell-scaffold constructs, scaffold with purified Leydig cells or co-cultured testis somatic cells (seed cells), were implanted into the gastrocolic omentum or cavity of tunica vaginalis of the castrated rats. The implants were harvested 4, 6, 9, 12, and 24 weeks later to evaluate the tissue formation of cell-scaffold constructs in vivo. The serum testosterone level of the implanted rats was assayed to evaluate the testosterone secreting function of the regenerative tissue.

Both the co-cultured testis somatic cells and Leydig cells had fine compatibility with the PGA fibers and adhered to the scaffolds very well. Testosterone was detected at a certain degree in the supernatant of cell-scaffold constructs, indicating the testosterone secreting function of the constructs. Two months after the implantation both kinds of cell-scaffold constructs formed testosterone secreting tissue in both gastrocolic omentum and cavity of tunica vaginalis of the implanted rats. The regenerative tissues were vascularized very well with a certain size and shape. Six weeks after implantation the serum testosterone level of the Leydig cell group was 0.60 ng/ml +/- 0.04 ng/ml, and that of the co-culture group was 0.84 ng/ml +/- 0.03 ng/ml, both significantly higher than that of the control castrated rats (0.56 ng/ml +/- 0.05 ng/ml, both P < 0.01), and the serum testosterone level of the co-cultured testes somatic cell implantation group was significantly higher than that of the Leydig cell implantation group too (P < 0.01).

It is completely feasible to construct androgen-secreting tissue in vitro and in vivo using tissue engineering technique. Co-cultured testis somatic cells may serve as the better seed cells for androgen-secreting tissue engineering than purified Leydig cells in terms of the quantity and function of cells.