Pre-clinical evaluation of soybean-based wound dressings and dermal substitute formulations in pig healing and non-healing in vivo models

In the last decade, a new class of natural biomaterials derived from de-fatted soybean fl our processed by either thermoset or
extraction procedures has been developed. These biomaterials uniquely combine adaptability to various clinical applications to
proven tissue regeneration properties. In the present work, the biomaterials were formulated either as hydrogel or as paste formulation
and their potential as wound dressing material or as dermal substitute was assessed by two in vivo models in pig skin:
The healing full-thickness punch biopsy model and the non-healing full-thickness polytetrafl uoroethylene (PTFE) chamber model.
The results clearly show that collagen deposition is induced by the presence of these biomaterials. A unique pattern of early infl ammatory
response, eliciting neutrophils and controlling macrophage infi ltration, is followed by tissue cell colonization of the wound
bed with a signifi cant deposition of collagen fi bers. The study also highlighted the importance in the use of optimal formulations
and appropriate handling upon implantation. In large size, non-healing wounds, wound dermis was best obtained with the paste
formulation as hydrogels appeared to be too loose to ensure lasting scaff olding properties. On the contrary, packing of the granules
during the application of paste reduced biomaterial degradation rate and prevent the penetration of newly vascularized tissue, thus
impeding grafting of split-thickness autologous skin grafts on the dermal substitute base.