Platelet-rich plasma can enhance the proliferation of human adipose-derived stem cells and human dermal fibroblasts. These results support clinical platelet-rich plasma application for cell-based, soft-tissue engineering and wound healing.

Platelet-rich plasma (PRP) is blood plasma that has been enriched with platelets. It holds promise for clinical use in areas such as wound healing and regenerative medicine, including bone regeneration. This study characterized the composition of PRP produced by seven commercially available separation systems (JP200, GLO PRP, Magellan Autologous Platelet Separator System, KYOCERA Medical PRP Kit, SELPHYL, MyCells, and Dr. Shin's System THROMBO KIT) to evaluate the platelet, white blood cell, red blood cell, and growth factor concentrations, as well as platelet-derived growth factor-AB (PDGF-AB), transforming growth factor beta-1 (TGF-β1), and vascular endothelial growth factor (VEGF) concentrations. PRP prepared using the Magellan Autologous Platelet Separator System and the KYOCERA Medical PRP Kit contained the highest platelet concentrations. The mean PDGF-AB concentration of activated PRP was the highest from JP200, followed by the KYOCERA Medical PRP Kit, Magellan Autologous Platelet Separator System, MyCells, and GLO PRP. TGF-β1 and VEGF concentrations varied greatly among individual samples, and there was almost no significant difference among the different systems, unlike for PDGF. The SELPHYL system produced PRP with low concentrations of both platelets and growth factors. Commercial PRP separation systems vary widely, and familiarity with their individual advantages is important to extend their clinical application to a wide variety of conditions.

Human adipose-derived stem cells (ASCs) have the capacity to regenerate and the potential to differentiate into multiple lineages of mesenchymal cells. The aim of this study was to investigate the possibility of using honeycomb collagen scaffold to culture ASCs in bone tissue engineering. The osteogenic capacity of ASCs in vitro, was confirmed by histology and measuring the expression of cbfa-1. After that, ASCs were cultured for up to 14 days in the honeycomb scaffold to allow a high density, three-dimensional culture. Scanning electron microscopy data showed that the scaffold was filled with the grown ASCs, and calcification, stained black with von Kossa, was confirmed. Furthermore, The ASC-loaded honeycomb collagen scaffolds cultured for 14 days were subcutaneously transplanted into nude mice, and excised after 8 weeks. Bone formation in vivo was examined using HE stain, von Kossa stain, and osteocalcin immunostain. Those histological views showed significant positive stains in the samples of osteogenic medium in the three types of stain. These results suggest that this carrier is a suitable scaffold for ASCs and will be useful as a three-dimensional bone tissue engineering scaffold in vitro and in vivo.

Platelet-rich plasma (PRP) is a plasma fraction in which several growth factors are concentrated at high levels. In recent years, the biological effects on various cells of the active soluble releasate that is isolated following platelet activation of PRP [PRP-releasate (PRPr)] have been reported. The purpose of this study was to determine the angiogenic effects of human PRPr in vitro and in vivo. PRPr was prepared from human whole blood using the double spin method and was activated with CaCl2 and autologous thrombin. PRPr stimulated proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) and in vivo angiogenesis-inducing ability in nude mice. PRPr led to the phosphorylation of Erk1/2 and Akt in HUVECs, and the induction of proliferation and migration by PRPr was suppressed by PRPr inhibitors PD98059 and LY294002. PRPr induces angiogenesis in vitro and in vivo, and the present findings suggest that the mechanism for this is activation of the ERK and phosphatidylinositol-3-kinase-Akt pathways. Our results demonstrate that PRPr is a promising autologous source for therapeutic angiogenesis in treating cardiovascular disease.

Autologous platelet-rich plasma contains multiple growth factors. We performed a side-by-side (half-side) test between the platelet-rich plasma (PRP)-treated and control (untreated) sides of a split-thickness skin graft donor site, and compared the number of days until epithelialization and pain during gauze change. On day 13 after surgery, we performed punch biopsy on the two sides and for adjacent normal skin tissue and compared the epidermal thickness and numbers of collagen fibers and newly formed vessels in the dermis by H&E staining, elastica van Gieson staining, and α-smooth muscle actin (α-SMA) immunostaining. Epithelialization progressed more rapidly, pain during gauze change was milder, and the epidermal thickness and number of newly formed vessels in the dermis were significantly greater on the PRP-treated side. This study revealed that PRP promotes epithelialization and angiogenesis of split-thickness skin graft donor sites.