Human Adipose-Derived Endothelial Progenitor Cells Accelerate Epithelialization of Radiation Ulcers in Nude Mice.

BACKGROUND: Cotransplantation of adipose-derived stem cells (ASCs) and endothelial progenitor cells has shown superior angiogenic effects compared with ASCs alone in recent animal studies. However, endothelial progenitor cells could only be collected from blood vessels or bone marrow. Thus, the authors have established a method for purifying adipose-derived endothelial progenitor cells (AEPCs). The authors hypothesized that AEPCs would enhance the therapeutic effect of ASCs on radiation ulcers. METHODS: Seven-week-old male nude mice (BALB/cAJcl-nu/nu) were irradiated on the dorsal skin (total 40 Gy); 12 weeks later, 6-mm-diameter wounds were created. The mice were then treated with subcutaneous injection of human ASCs [1 × 10 5 ( n = 4)], human AEPCs [2 × 10 5 or 5 × 10 5 ( n = 5)], combinations of those [ASCs 1 × 10 5 plus AEPCs 2 × 10 5 ( n = 4) or 5 × 10 5 ( n = 5)], or only vehicle ( n = 7). The nonirradiated group was also prepared as a control ( n = 6). The days required for macroscopic epithelialization was compared, and immunostaining for human-derived cells and vascular endothelial cells was performed at day 28. RESULTS: AEPC-ASC combination-treated groups healed faster than the ASC-treated group (14 ± 0 days versus 17 ± 2 days; P < 0.01). Engraftment of the injected cells could not be confirmed. Only the nonirradiated mice had significantly higher vascular density (0.988 ± 0.183 × 10 -5 /µm -2 versus 0.474 ± 0.092 × 10 -5 /µm 2 ; P = 0.02). CONCLUSION: The results suggested therapeutic potentials of AEPCs and an enhanced effect of combination with ASCs. This study is a xenogenic transplantation model, and further validation in an autologous transplantation model is needed. CLINICAL RELEVANCE STATEMENT: Human AEPCs and their combination with ASCs accelerated epithelialization of radiation ulcers in nude mice. The authors suggest that administration of humoral factors secreted from AEPCs (eg, treatment with culture-conditioned media) could be used for the same purpose.

Adipose-Derived Stem Cell Conditioned Medium and Wound Healing: A Systematic Review.

Adipose-derived stem cells (ASCs) have been growing in popularity for their potential in wound healing and tissue engineering. Stem cell therapies are limited in application, with the need to maintain cell viability and function as well as safety concerns. It has been increasingly reported that the effects of ASCs are predominantly attributable to the paracrine effects of the secreted factors, which can be collected in conditioned medium (CM). The goal of this systematic review was to investigate the effects on wound healing of CM collected from ASC culture. Original articles relevant to ASC-CM and wound healing (in vitro: dermal fibroblast, epidermal keratinocytes, and their equivalent cell lines; in vivo: full-thickness wound models) were included. The agreement level of selections between two investigators was calculated by the kappa scores. And the information concerning to the publications, CM preparation, and its application and effects was extracted and reported in a systematic way and summarized in tables. In total, 121 publications were initially identified through a search of the PubMed/MEDLINE database with a specific search algorithm, and 36 articles were ultimately included after 2 screenings. Nineteen were in vitro studies that met the search criteria and 17 were in vivo studies with or without in vitro data. In summary, based on the included articles, treatment with ASC-CM, to a large extent, resulted in positive effects on wound healing in vitro and in vivo. Modulation of the culture conditions of ASCs producing the CM, including hypoxic conditions, alternative substrates, medium supplementation, as well as genetic modification of cells, favorably promoted the effects of ASC-CM. Finally, a discussion of the future perspectives and therapeutic potential of ASC-CM, which also addresses the limitations of the field, is presented. A limitation of the evidence is the inconsistency in CM preparation methods among included articles. In conclusion, ASC-CM is a promising novel cell-free therapy for wound healing in regenerative medicine and warrants further exploration. Impact Statement This systematic review researched in vitro and in vivo studies regarding therapeutic effects of adipose-derived stem cell (ASC) conditioned medium (CM) on wound healing, generally indicating favorable effects. ASC-CM can avoid safety concerns accompanying stem cell therapies and reduce the cost of treatment. Modulation in the process of ASC culture and CM preparation may promote its therapeutic potential. The limitation and future perspectives of the field of ASC-CM therapy were also presented. ASC-CM may be useful to its future application for a wide range of clinical targets including inflammatory and ischemic diseases.

Clinical applications of ear reconstruction with Medpor.

OBJECTIVE: To discuss clinical practice, efficacy and surgical techniques for ear reconstruction with Medpor.
 Methods: Medpor ear reconstructions were used to treat 19 microtia in 17 patients (including 2 bilateral patients) in Xiangya Hospital, Central South University from January 2011 to December 2015. Reconstructions included 2 patients with one-stage ear reconstruction with temporoparietal fascial flap, 2 patients with one-stage operation implanting Medpor directly into skin pocket, and 13 patients with two-stage ear reconstruction.
 Results: After 1-3 years of follow-up, 16 microtia in 14 patients gained ideal appearance. Scaffold exposure occurred in 3 unilateral cases, among which one patient who underwent debridement, removal of superficial exposed scaffold and transposition of local flap to salvage exposure was not significantly influenced, and the other 2 patients' scaffolds were still exposed after repairs and finally removed. One stent was removed at the patient's urging because it induced an exacerbation of periarthritis of the right shoulder.
 Conclusion: Medpor ear scaffold has advantages, such as easy assembly, good immunologic compatibility, fast vascular ingrowth, simple operation, short operative time and ideal appearance of the reconstructed ear. Medpor is an alternative for microtia repair when patients are unwilling to use autologous rib cartilage or costal cartilages are calcified. However, the relatively high incidence of scaffold exposure reminds us that the indications of Medpor should be taken seriously, and measures to avoid skin necrosis and scaffold exposure should be implemented. Long-term follow-up efficacy needs to be proved.