Platelet-derived concentrates influence human keratinocyte proliferation in vitro and induce wound healing in a prospective case series of chronic wounds of different entities in vivo

Abstract

Objectives: Soft tissues defects can extend into the fat layer or even deeper and can cause significant clinical disadvantages like pain, infections, and loss of function. In particular, chronic wounds are difficult to treat, as split-thickness skin grafts (STSGs) have varying success rates. To improve wound healing in chronic wounds, the authors have studied the application of platelet-mediator concentrate (PMC) in a human keratinocyte culture model in vitro and of autologous platelet concentrates (PRP) in a combination with surgical procedures in vivo as second line therapy in patients with initially failed wound closure.

Methods: For in vitro testing on keratinocytes, a PMC was processed with a commercially available bedside system (ATR®, Curasan, Germany). In a clinical, nonrandomized study, five in-house patients with chronic wounds were treated using a combination of surgical debridement and autologous PRP. Time of healing as determined by epithelization as well as laser Doppler imaging to visualize blood flow was analyzed. Additionally, changes in ease of surgical wound closure were determined. Finally, the quality of life of patients was assessed using a validated questionnaire (clinicaltrials.gov # NCT03667638).

Results: In vitro testing shows a significant effect of PMC on keratinocyte proliferation in cell culture. Clinical studies showed that patients treated with PRP had initiation of wound closure, higher blood flow after PRP injection, and easier wound closure as well as improved quality of life.

Conclusions: The injection of platelet concentrates to treat chronic wound defects presents a favorable addition to treatment where single surgical procedures have failed and may improve current therapy options.

Keywords: PRP; autologous platelet plasma; chronic wound; ease of surgical wound closure; laser Doppler imaging; wound healing; wound quality of life.

Conflict of interest statement

Competing interests: All Authors state no conflict of interest.

© 2022 the author(s), published by De Gruyter, Berlin/Boston.

Figures

Figure 1:

Consolidated standards of reporting trials (CONSORT) flow chart for the intervention with PRP.

Figure 2:

Examples of PRP injection in patient °1 (A) as well as patient °2 (B + C). Injections into wound base at day 0 (B) and wound margin (C) at day 14. All wounds had PRP injection into wound margins and base every time.

Figure 3:

Examples of wound healing in patient °1 (A) and patient °2 (B). The first row shows patient °1 had large undermined wound edges (first picture on day 0), which greatly decreased after PRP injection (second picture on day 21). The second row (B) shows patient °2 on days 0, 7, 14, and 21. The wound area reduced after STSG due to contraction.

Figure 4:

LDI of patient 5 on day 0 (A) and day 7 (B). Shown are measurements of wound margin, wound base, and regular skin. Perfusion is shown as scale in Perfusion Units (0–300 PU): light gray/white equals low blood flow, black/dark equals high blood flow. Picture B has higher perfusion in wound ground and margin, indicating an angiogenetic effect after the injection of PRP.

Figure 5:

Keratinocyte culture assays using PMC. (A and B) Proliferation assays using 1 and 10% PMC. Higher concentration of PMC shows higher proliferation rates with significant differences after 48 and 72 h. (C and D) Scratch/migration assays using 1 and 10% PMC. PMC effect on proliferation and migration is also concentration dependent.

Figure 6:

Wound areas of all patients in mm2 over time. All patients had arrested wound healing before. After injection with PRP, a significant reduction in wound area was observed. D, debridement; PRP, platelet-rich plasma; STSG, split-thickness skin graft.

Figure 7:

Average wound area in percentage (%). After PRP injection, there is a reduction in wound area. This effect is statistically most significant after the first injection. Data are compiled from 5 patients. *: p-value

Figure 8:

Rate of wound area reduction. After PRP injection, there is a significant change in the rate of healing, *: p-value

Figure 9:

After PRP injection, there is a difference in perfusion in the wound base and especially in the wound margin. This change in perfusion is most visible after the first PRP-injection. Data are compiled from 5 patients. **: p-value