Adipogenesis of bioabsorbable implants under irradiation in a rodent model

Breast cancer is the most common cancer among women. Partial mastectomy is an alternative to mastectomy in early-stage breast cancer to restore a poor quality of life (QOL). However, the aesthetic satisfaction with this procedure is inadequate. The standard methods for breast reconstruction have certain limitations. We developed bioabsorbable implants consisting of an outer mesh composed of poly L-lactic acid (PLLA) and an inner component filled with a collagen sponge (CS). These implants were designed to promote and sustain adipogenesis in vivo, without the addition of exogenous cells or growth factors. In this study, we used PLLA mesh implants to investigate the effects of irradiation on fat formation, which is important in partial mastectomy.

The implants were inserted into both the inguinal regions of the rats. One month after the implantation, a dose of 13 Gy was delivered to the left-side implants. We compared adipose tissue formation in the non-irradiated and irradiated groups at 6 and 12 months after irradiation.

Irradiation of implants did not lead to malignant tumor formation. The newly formed tissues and adipose tissue were not significantly different between the two groups at 6 and 12 months after irradiation.

PLLA mesh implants containing CS are desirable bioabsorbable implants that can be replaced with autologous adipose tissue after in vivo implantation under irradiation. These implants serve as an effective material for partial mastectomy and have the potential to improve the QOL of patients after mastectomy.