Optimizing the timing of autologous skin cell suspension after enzymatic debridement of porcine burns: Evaluation with digital image speckle correlation

Enzymatic debridement preserves viable dermis in deep partial-thickness burns, yet the optimal timing of autologous skin cell suspension (ASCS) delivery remains unclear. We evaluated whether ASCS enhances biomechanical restoration after enzymatic debridement, whether a 24-hour delay alters outcomes, and whether digital image speckle correlation provides a sensitive, noninvasive measure of healing. In a porcine dorsal burn model, wounds were treated with ASCS immediately or 24 hours after enzymatic debridement, with bacitracin serving as control. Digital image speckle correlation measurements quantified force propagation across the wound bed using optical-flow method, whereas histology assessed re-epithelialization and dermal remodeling. Complementary in vitro studies examined cytotoxicity of residual debridement enzyme. ASCS significantly increased the restoration of force propagation compared with bacitracin by day 28 (P < .0001), indicating improved biomechanical integration of the wound bed. Immediate and delayed ASCS application produced similar healing trajectories, with modest differences at the final time point. Enzyme concentrations ≤0.5% preserved viability, whereas higher concentrations were detrimental. Digital image speckle correlation measurements paralleled histological remodeling and revealed spatially resolved mechanical recovery not captured by ordinal clinical or histological scoring systems. Together, these findings establish digital image speckle correlation as a noninvasive method for assessing wound healing and support early ASCS application after enzymatic debridement without compromising biomechanical recovery.