Melatonin promotes survival of nonvascularized fat grafts and enhances the viability and migration of human adipose-derived stem cells via down-regulation of acute inflammatory cytokines.

Nonvascularized fat grafting is a valuable technique for soft tissue reconstruction but poor survival of fat in the host environment remains a problem. A process known as cell-assisted transfer is used to enhance fat graft retention by adding stromal vascular fraction, an adipose-derived stem cell (ASC) rich content to lipoaspirate. We have recently shown that the use of melatonin, a reactive oxygen species scavenger, protects human ASCs from hydrogen peroxide-induced oxidative stress and cell death in vitro but its role as a pharmacological adjunct in clinical fat grafting has not been studied. Herein, the effect of melatonin was examined on human ASCs in vitro using survival and functional assays including the MTT assay, CellTox Green assay, monolayer scratch assay as well as a human cytokine chemoluminescence, and tumour necrosis factor-α assay. Further, the effect of melatonin-treated fat grafts was tested in vivo with a murine model. Haematoxylin and eosin staining, perilipin and CD31 immunostaining were performed with morphometric analysis of adipose tissue. The results demonstrate that, in vitro, the addition of melatonin to ASCs significantly improved their cell-viability, promoted cell migration and preserved membrane integrity as compared to controls. In addition, it induced a potent anti-inflammatory response by downregulating acute inflammatory cytokines particularly tumour necrosis factor-α. For the first time, it is demonstrated in vivo that melatonin enhances fat graft volume retention by reducing inflammation and increasing the percentage of adipose volume within fat grafts with comparable volumes to that of cell-assisted lipotransfer. Based on these novel findings, melatonin may be a useful pharmacological adjunct in clinical fat grafting.

A Streamlined Method for the Preparation of Growth Factor-enriched Thermosensitive Hydrogels from Soft Tissue.

Hydrogels are an ideal medium for the expansion of cells in three dimensions. The ability to induce cell expansion and differentiation in a controlled manner is a key goal in tissue engineering. Here we describe a detailed method for producing hydrogels from soft tissues with an emphasis on adipose tissue. In this method, soluble, extractable proteins are recovered from the tissue and stored while the remaining insoluble tissue is processed and solubilised. Once the tissue has been sufficiently solubilised, the extracted proteins are added. The resulting product is a thermosensitive hydrogel with proteins representative of the native tissue. This method addresses common issues encountered when working with some biomaterials, such as high lipid content, DNA contamination, and finding an appropriate sterilisation method. Although the focus of this article is on adipose tissue, using this method we have produced hydrogels from other soft tissues including muscle, liver, and cardiac tissue.

Aggressive behavior of cutaneous squamous cell carcinoma in patients with chronic lymphocytic leukemia.

OBJECTIVES/HYPOTHESIS: Immunosuppression in organ transplant recipients increases the incidence and aggressiveness of cutaneous squamous cell carcinoma. However, there are little clinical data on cutaneous squamous cell carcinoma in patients with immunosuppression due to chronic lymphocytic leukemia. In this study we evaluated the clinical features, patterns of recurrence, and outcomes of cutaneous squamous cell carcinoma in patients with chronic lymphocytic leukemia. STUDY DESIGN: Retrospective cohort study. METHODS: A review was performed of 42 consecutive patients with cutaneous squamous cell carcinoma and chronic lymphocytic leukemia presenting to our institution between July 2000 and July 2010. Baseline characteristics, treatment details, and outcomes were analyzed. RESULTS: Thirty-four patients presented with primary cutaneous squamous cell carcinoma (33 node negative, 1 node positive), and eight patients presented with nodal disease without a simultaneous index primary. The 2-year cumulative incidence of local recurrence for primary cutaneous squamous cell carcinoma was 15%. Nodal recurrence occurred in 36% of node-negative patients. The 3-year overall and cause-specific survival rate for all patients was 37% and 65%, respectively. In patients managed curatively for nodal disease at presentation or relapse (n = 17), the 3-year overall and cause-specific survival rate was 21% and 53%, respectively. CONCLUSIONS: Patients with cutaneous squamous cell carcinoma and chronic lymphocytic leukemia experience higher rates of skin cancer recurrence and death than expected in an immunocompetent population. Novel strategies are needed to improve outcomes.