[Show abstract][Hide abstract] ABSTRACT: We evaluated growth factor contents and clinical efficacy of allogeneic platelet gel (PG) prepared with standard blood banking procedures from routine platelet concentrates (PCs) obtained from buffy coats. The PGs were used to treat 11 hypomobile very elderly patients unable to undergo autologous blood processing and previously ineffectively treated with expensive advanced medications for 8-275 weeks. PGs were prepared by platelet activation with human thrombin or commercial batroxobin. Median and range growth factor contents (ng/mL) were: platelet derived growth factor (PDGF-AB/-BB) 112 (31-157) and 20 (3.8-34); transforming growth factor (TGF-β1/-β2) 214 (48-289) and 0.087 (0.03-0.28); basic-fibroblast growth factor (b-FGF) 0.03 (0.006-0.214); vascular endothelial growth factor (VEGF) 1.15 (0.18-2.46); epidermal growth factor (EGF) 4.50 (0.87-6.64); insulin-like growth factor (IGF-l) 116 (72-156). In the clinical study, 222 PGs were used within 2 h of activation to treat 14 chronic skin ulcers in the 11 patients. No improvement was seen in 3 patients with 24, 27 and 30 cm(3) ulcers who could be treated for no more than 4, 7 and 8 weeks due to progressively worsening clinical conditions, while 11 ulcers with 3.2 cm(3) median size (range 0.2-3.6) in the remaining 8 patients showed 91 ± 14 % reduction after a median of 12 weeks (range 1-20). Cost of PG treatment (19,976 euro) amounted to about 10% of the ineffective advanced medication hospital reimbursement fees (191,236 euro). This study supports efficacy and feasibility of allogeneic PG to treat recalcitrant ulcers in very elderly hypomobile patients for whom autologous blood processing may be difficult.