Treatment of skin defects with growth factors and biodegradable collagen carrier: Histological evaluation in animal model

The aim of the present study is to evaluate the effects on skin regeneration of a new collagen matrix (CM-10826) when used in different combination with or without growth factors, using skin regeneration without membrane as control. An area of 10x15 cm on rabbit back was shaved and three circular wounds on test side were covered with a differently soaked membrane. The first wound was soaked with Epidermal Growth Factor (EGF, 26mg/130mL) (Test EGF), the second with Platelet-Derived Growth Factor (PDGF, 6mg/120mL) (Test PDGF) and the third with EGF (13mg/65mL) and PDGF (3mg/60mL) (Test EGF+PDGF). On the control side, there was a dry membrane. After 7 days, the experiment was concluded. Healing process was evaluated at day 2 and 6 postoperatively. Analysis was made clinically and with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Analyses with LM of Test EGF showed evidence of neoangiogenesis and good epithelium growth. Test PDGF resulted in moderate angiogenesis, less evident epithelial growth and more evident mesenchymal growth than Test EGF. Test EGF+PDGF showed rich angiogenesis, massive growth of epithelium and mesenchymal tissue. Control side showed weak angiogenesis, regenerating wound margin with normal epithelium and less dense mesenchymal layer. Analysis at TEM and SEM confirmed what was noticed at LM. In vivo studies on rabbits have shown that membrane CM10826 is well tolerated, it gives neither inflammation nor foreign body reactions and does not disturb healing process. CM10826 is safe, modulates angiogenesis and induces migration and proliferation of keratinocytes.