Lyophilized non-denatured type-I collagen (Condress) extracted from bovine Achilles' tendon and suitable for clinical use.

On account of the biological role of collagen in wound healing, and because of its biocompatibility, the use of heterologous collagen-based devices is becoming more widespread. Here we describe the extractive procedure and properties of a lyophilized type-I collagen (Condress) suitable for clinical use. Condress is extracted from bovine Achilles' tendon through a non-denaturing procedure in the absence of proteolytic enzymes. It has not been submitted to a chemical cross-linking process before lyophilization. Chemical identification of Condress as type-I acid-insoluble collagen has been carried out by evaluation of total nitrogen and hydroxyproline contents and by chromatographic examination. Electrophoretic analysis and morphological examination by electron microscopy confirm that the procedure employed to extract collagen does not alter the polypeptidic composition of the molecule and its structure. A gamma-ray dose between 0.5 and 1.5 Mrad is quite adequate to sterilize the final product and certainly devoid of degradative effect. The finished product has a special (peculiar) absorbing capacity, immersion time, strain resistance, wrinkling temperature and enzymatic digestion time. It is a nonallergenic product suitable for clinical use. When it has been applied in chronic leg ulcers, pressure sores, or reconstructive surgery, Condress seems to substantially improve wound repair.