Development of Autologous Platelet-Rich Plasma Mixed-Microfat as an Advanced Therapy Medicinal Product for Intra-Articular Injection of Radio-Carpal Osteoarthritis: From Validation Data to Preliminary Clinical Results.

Wrist osteoarthritis (OA) is one of the most common conditions encountered by hand surgeons with limited efficacy of non-surgical treatments. The purpose of this study is to describe the Platelet-Rich Plasma (PRP) mixed-microfat biological characteristics of an experimental Advanced Therapy Medicinal Product (ATMP) needed for clinical trial authorization and describe the clinical results obtained from our first three patients 12 months after treatment (NCT03164122). Biological characterization of microfat, PRP and mixture were analysed in vitro according to validated methods. Patients with stage four OA according to the Kellgren Lawrence classification, with failure to conservative treatment and a persistent daily painful condition >40 mm according to the visual analog scale (VAS) were treated. Microfat-PRP ATMP is a product with high platelet purity, conserved viability of stromal vascular fraction cells, chondrogenic differentiation capacity in vitro and high secretion of IL-1Ra anti-inflammatory cytokine. For patients, the only side effect was pain at the adipose tissue harvesting sites. Potential efficacy was observed with a pain decrease of over 50% (per VAS score) and the achievement of minimal clinically important differences for DASH and PRWE functional scores at one year in all three patients. Microfat-PRP ATMP presented a good safety profile after an injection in wrist OA. Efficacy trials are necessary to assess whether this innovative strategy could delay the necessity to perform non-conservative surgery.

[Keloid scars: a case series study]. / Cicatrices chéloïdes : étude d'une série de cas.

Keloids scars are a pathological way of wound healing of the human skin. They are responsible for an unsightly and functional discomfort, and recurrence is common after surgery. There are specific treatments in order to lower this risk. They can be hard to distinguish from an hypertrophic scar on clinical and histological examination. Moreover, mixed forms exist, combining keloid and hypertrophic features. We retrospectively reviewed 52 patients who underwent surgery for keloid scars. On 54 scars, histological examination found 38 keloids, 8 hypertrophic, 7 mixed scars and 2 neither keloid nor hypertrophic. Mean age was 30 years. Sex ratio was 1.2 women per 1 man. Most frequent locations were ear (44.4%), thorax (33.3%), and shoulder (7.4%). In all cases, disease duration exceeded one year. Histology help to make the definitive diagnosis of keloid, hypertrophic and mixed scar, confirmed by trichrome or orcein staining and alpha smooth muscle actin immunostaining.

Supportive use of platelet-rich plasma and stromal vascular fraction for cell-assisted fat transfer of skin radiation-induced lesions in nude mice.

BACKGROUND: External radiotherapy has become indispensable in oncological therapies. Unfortunately, radiation is responsible for serious side effects, such as radiodermatitis. The skin is weakened and ulcerated. Our study aimed to evaluate the subcutaneous transfer of microfat (MF) alone and two mixes: MF+Platelet-rich plasma (PRP) and MF+stromal vascular fraction (SVF) to treat radiation-induced skin lesions. METHOD: We defined randomly five experimental groups of nine mice: 1 healthy control group and 4 irradiated (60 Grey) and treated groups. The skin lesions were treated 3 months after irradiation by MF, MF+PRP (50%-50%), MF+SVF (90%-10%) or Ringer-lactate subcutaneous injections. Wound healing was evaluated at 1, 2 and 3 months post-injection and histological wound analysis at 3 months, after euthanasia. RESULTS: All the irradiated mice presented with wounds. After sham-injection, the wound area increased by 91.1±71.1% versus a decrease of 15.9±23.1% after MF alone (NS), 27.3±23.8% after MF+SVF (NS) and 76.4±7.7% after MF+PRP (P=0.032). A significative reduction of skin thickness in wound periphery was measured for the three treated groups compared to sham-injection (P<0.05) but not in the healed wounds (NS). The most important subcutaneous neo-vessel density was shown after MF+SVF injection. CONCLUSION: The MF+PRP mix was the most efficient product to increase healing. The MF+SVF mix showed the highest rate of neo-angiogenesis but was disappointing in terms of healing. LEVEL OF EVIDENCE: Not gradable.

Combined use of platelet rich plasma & micro-fat in sport and race horses with degenerative joint disease: preliminary clinical study in eight horses.

BACKGROUND: To assess the safety and potential efficacy of a standardized technique consisting of intra-articular injection of 10 cc of a homogeneous mixed product using autologous micro-fat and platelet rich plasma (PRP) (ratio 1:1) in the carpus or the fetlock joint of sport horses presenting degenerative joint disease (DJD). METHODS: Eight sport horses with DJD confirmed by radiography and ultrasonography and causing lameness and the impossibility to compete were treated. PRP was prepared after a double centrifugation whereas micro-fat was harvested and purified using a closed system. The two products were connected and mixed by gentle back and forth shaking of the syringes to finally obtain 10 ml of an homogeneous mixed product. Follow up was performed from 5 to 10 months with assessment of AAEP lameness score and return to training and competition. RESULTS: Nine joints were treated with significant improvement of the AAEP lameness score three months after the procedure (p = 0.021). Four horses returned to official competition between 5 to 10 months after the procedure (7.0±2.5) and three of them resumed intensive training between 5 to 9 months (6.3±2.3). No adverse event occurred. CONCLUSION: This study is a first step in the development of innovative therapy for DJD which combines the potential chondrogenic differentiation of MSCs inside equine adipose tissue with the proliferative effect of growth factors present in PRP.