Adult adipose-derived stem cells (ASCs) are a type of multipotent mesenchymal stem cells (MSCs) with easy availability and serve as a potential cell source for cell-based therapy. Three-dimensional MSC spheroids may be derived from the self-assembly of individual MSCs grown on certain polymer membranes. In this study, we demonstrated that the self-assembled ASC spheroids on chitosan-hyaluronan membranes expressed more cytokine genes (fibroblast growth factor 1, vascular endothelial growth factor, and chemokine [C-C motif] ligand 2) as well as migration-associated genes (chemokine [C-X-C motif] receptor type 4 and matrix metalloprotease 1) compared with ASC dispersed single cells grown on culture dish. To evaluate the in vivo effects of these spheroids, we applied ASC single cells and ASC spheroids in a designed rat skin repair model. Wounds of 15 × 15 mm were created on rat dorsal skin, where ASCs were administered and covered with hyaluronan gel/chitosan sponge to maintain a moist environment. Results showed that skin wounds treated with ASC spheroids had faster wound closure and a significantly higher ratio of angiogenesis. Tracking of fluorescently labeled ASCs showed close localization of ASC spheroids to microvessels, suggesting enhanced angiogenesis through paracrine effects. Based on the in vitro and in vivo results, the self-assembled ASC spheroids may be a promising cellular source for skin tissue engineering and wound regeneration.

ADSC spheroids derived on various biomaterials present different in vitro properties, which may explain their different efficacies in cartilage repair.

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Platelet-rich plasma (PRP) is a kind of plasma that is rich in platelets after processing. It includes various growth factors and cytokines, which speed up the process of wound healing and hemostasis. The PRP solution used in this study is diluted from lyophilized PRP powder, which decreased the possibility of contamination, facilitated the storage, and prolonged the storage life. From in vitro fibroblast proliferation testing, the numbers of PRP supplement were performed for 1, 4, and 7 times by continuous replacement of culture medium each day. Four times of lyophilized PRP supplement was selected for clinical study due to sufficient promotion of fibroblast proliferation. Next, 27 patients of deep second-degree burn wound were included in this study. Patients were assigned to two groups: PRP group (n = 15) and control group (n = 12). A concentration of 1.0 × 10 platelets/cm (wound area) according to wound size was sprayed on the wound evenly. Function was mainly assessed by the percentage of wound closure and bacteria picking out rate in 2 and 3 weeks. The wound closure at 3 weeks showed a significant difference in PRP group (P < 0.05). The healing rate of PRP group reached nearly 80% and made a breakthrough of 90% in 3 weeks, showing a significant difference compared with the control group (P < 0.05). Lyophilized PRP can be considered as an effective treatment to increase healing rate in patients with deep second-degree burn injury.