The unilocular fat-cell graft

SummaryAutologous fat grafting has become a common procedure for augmenting soft tissue. However, there are still some problems with resorption and cyst formation after injection, which mainly arise from insufficient nourishment of the transplanted fat tissues. In this study, using a mouse model, we enzymatically digested fat tissues into unilocular fat cells, and then transplanted the unilocular fat cells by sub-dermal injection to allow the transplanted cells to easily spread within the injected area. Fat tissue was harvested from a green fluorescent protein transgenic mouse (C57BL/6), and the optimal digestion time was determined to be 30 min. The fat cells were then injected into the sub-dermal layer of the head skin of a C57BL/6 mouse. As a control, minced fat without digestion was also injected. The animals were sacrificed immediately after injection and on days 1, 2 and 3, as well as at weeks 1, 2 and 4 after injection, and the recipient skins were collected for microscopic observation. The unilocular fat cells were observed to spread in a solitary manner among the recipient tissues, and no necrotic areas or cysts were observed. The minced-fat-graft control showed central necrosis in the transplanted region. In addition, the minced fat tissue needed to be injected with an 18-gauge syringe, but the unilocular fat cells could be injected with a 26-gauge syringe. Thus, the unilocular fat-cell graft was determined to be a superior alternative to conventional fat grafts.