Effect of aging on the osteoinductive activity of recombinant human bone morphogenetic protein-2 in rats.

BACKGROUND: Bone morphogenetic proteins may hold broad potential for use in the reconstruction of bone defects resulting from tumor resection or trauma and in assisting bone healing thanks to methods enabling the synthesis of recombinant human bone morphogenetic protein-2 (rhBMP-2). METHODS: rhBMP-2 was implanted with atelopeptide type I collagen as a carrier into the calf muscles of 3-, 8-, and 48-wk-old Wistar/ST male rats. After 21 d, the formation of ectopic neoplastic bone was examined in soft x-ray imaging, and the bone mineral content, bone area, and bone mineral density (BMD) were measured by dual-energy x-ray absorptiometry. In addition, hematoxylin-eosin and von Kossa staining and proliferation cell nuclear antigen immunostaining were performed. RESULTS: BMD values determined by dual-energy x-ray absorptiometry were 29.40 (standard deviation ±5.47), 24.15 (±2.33), and 19.01 (±2.02) mg/cm(2) in the 3-, 8-, and 48-wk-old rats, respectively, demonstrating that BMD significantly decreased with aging (P < 0.05). The von Kossa stain-positive area decreased significantly with aging (P < 0.01). The number of proliferation cell nuclear antigen-positive cells also decreased significantly with aging (P < 0.01). CONCLUSIONS: The capacity of rhBMP-2 to induce ectopic bone formation decreases with aging. These findings will be of considerable benefit in the development of clinical treatments for the regeneration of cranio-maxillofacial bone in elderly patients.

[Immediate breast reconstruction for breast cancer].

We performed immediate breast reconstruction after nipple-sparing mastectomy or skin-sparing mastectomy and evaluated the reconstruction procedure, cosmesis, and complications. Among the 30 patients included in the study, 6 received latissimus dorsi flaps, 1 received a transverse rectus abdominis myocutaneous flap, 7 received deep inferior epigastric perforator flaps, 1 received an implant, and 15 received tissue expanders. In addition, the results were excellent in 25 patients, good in 3 patients, and poor in 2 patients. As the number of patients with breast cancer is increasing, the demand for breast reconstruction will increase. Therefore, it is essential to choose an appropriate method of breast reconstruction for each case.

Exploratory clinical trial of combination wound therapy with a gelatin sheet and platelet-rich plasma in patients with chronic skin ulcers: study protocol.

INTRODUCTION: Chronic skin ulcers, such as diabetic ulcers, venous leg ulcers and pressure ulcers, are intractable and increasing in prevalence, representing a costly problem in healthcare. We developed a combination therapy with a gelatin sheet, capable of providing sustained release of platelet-rich plasma (PRP). The objective of this study is to investigate the safety and efficacy of autologous PRP covered with a hydrocolloid dressing and PRP covered with a gelatin sheet in the treatment of chronic skin ulcers. METHODS AND ANALYSIS: Thirty patients with chronic skin ulcers who have not healed with conventional therapy for at least 1 month are being recruited. The patients will receive PRP after debridement, and the wounds will be covered with a hydrocolloid dressing or gelatin sheet. The efficacy will be evaluated according to the time from the beginning of PRP application to secondary healing or the day on which wound closure is achieved with a relatively simple surgical procedure, such as skin grafting or suturing. All patients will be followed up until 6 weeks after application to observe adverse events related to the application of PRP and the dressings. This study was designed to address and compare the safety and efficacy of PRP covered with a hydrocolloid dressing versus a gelatin sheet. If successful, this combination therapy may be an alternative to bioengineered skin substitutes containing living cells and lead to substantial progress in the management of chronic skin ulcers. ETHICS AND DISSEMINATION: The study protocol was approved by the Institutional Review Board of Kansai Medical University (KMU Number 0649-1, 4 August 2014: V.1.0). The findings of this trial will be disseminated through peer-reviewed journals, and national and international scientific meetings as well as to the patients. TRIAL REGISTRATION NUMBER: UMIN000015689.

Effects of transforming growth factor-beta1 on cell motility, collagen gel contraction, myofibroblastic differentiation, and extracellular matrix expression of human adipose-derived stem cell.

Human adipose-derived stem cells (ASCs) are adult pluripotent stem cells, and their usefulness in plastic surgery has garnered attention in recent years. Although, there have been expectations that ASCs might function in wound repair and regeneration, no studies to date have examined the role of ASCs in the mechanism that promotes wound-healing. Transforming growth factor-beta1 (TGF-ß1) is a strong candidate cytokine for the triggering of mesenchymal stem cell migration, construction of extracellular matrices, and differentiation of ASCs into myofibroblasts. Cell proliferation, motility, and differentiation, as well as extracellular matrix production, play an important role in wound-healing. We have evaluated the capacity of ASCs to proliferate and their potential to differentiate into phenotypic myofibroblasts, as well as their cell motility and collagen gel contraction ability, when cultured with TGF-ß1. Cell motility was analyzed using a wound-healing assay. ASCs that differentiated into myofibroblasts expressed the gene for alpha-smooth muscle actin, and its protein expression was detected immunohistochemically. The extracellular matrix expression in ASCs was evaluated using real-time RT-PCR. Based on the results, we conclude that human ASCs have the potential for cell motility, extracellular matrix gene expression, gel contraction, and differentiation into myofibroblasts and, therefore, may play an important role in the wound-healing process.