RESUMO
OBJECTIVE: Platelet-rich plasma is blood plasma enriched with platelets and contains various growth factors. Two major issues remain to be resolved in the use of platelet-rich plasma: the short biological activity after application, and the need to prepare platelet-rich plasma at each application instance. To overcome these problems, we developed a drug delivery system using gelatin hydrogel and preserved the excess platelet-rich plasma as freeze-dried platelet-rich plasma. We then applied combination treatment with a gelatin sheet and platelet-rich plasma at the first instance and freeze-dried platelet-rich plasma at the second instance in the treatment of a nonhealing wound. METHODS: A 68-year-old woman had suffered open fracture of her right tibia 2 years prior, and a split-thickness skin graft had been applied to repair the skin defect on the right tibia. She had multiple relapse of ulcers, and the present ulcer had not healed for 2 months. After debridement, 2 mL of activated platelet-rich plasma was applied to the ulcer, and the gelatin sheet was laid to impregnate with the platelet-rich plasma, after which the sheet was covered with a polyurethane film. Thirty-three days after the first platelet-rich plasma application, the freeze-dried platelet-rich plasma was reconstituted and 2 mL of the reconstituted platelet-rich plasma was applied with a gelatin sheet. RESULTS: At 14 days after the freeze-dried platelet-rich plasma application, the wound was mostly epithelized, with the rest of the wound covered with granulation tissue. CONCLUSIONS: These findings suggest that combination wound therapy with a gelatin sheet and freeze-dried platelet-rich plasma is a promising method for resolving issues with conventional platelet-rich plasma treatment.
