The in vivo biocompatibility of novel tannic acid-collagen type I injectable bead scaffold material for breast reconstruction post-lumpectomy

Breast cancer is the most common invasive cancer in women worldwide. Surgical removal of the breast tumor and subsequent reconstructive surgery can result in complications such as infection or necrosis of transplanted adipose tissue. Breast cancer recurrence is also a serious concern for patients. Our group has developed a tannic acid/collagen bead material that has the potential to be used as an injectable adipose tissue regenerative device to replace lipofilling. Tannic acid is a polyphenol with anticancer and antibiotic properties. The objective of this study was to establish the biocompatibility of an injectable tannic acid/collagen bead implant material in an in vivo rat model. The injection of the tannic acid-collagen type I bead device was minimally invasive. No symptoms of infection, tissue necrosis, or widespread chronic inflammation were observed. After 12 weeks, implants showed incorporation into native tissue with no fibrous encapsulation. Despite the presence of inflammatory cells in the remaining beads, fat tissue growth and collagen redistribution were observed within the beads over 12 weeks, showing incorporation within native subcutaneous tissue and indicating good biocompatibility and bioactivity of the implant. Our results demonstrate that the tannic acid/collagen bead scaffold has good biocompatibility and works as an adipocyte tissue regeneration and reconstructive device.