Angiogenic factor from human term placenta. Purification and partial characterization.

Angiogenic and growth promoting factors from human amniochorion and placenta at term were released mostly as high molecular weight components (factor-carrier protein higher than 100,000 molecular weight) by extraction with 10% propan-2-ol, distilled water, and 50 mmol l-1 Tris/HCl pH 7.2 containing 50-150 mmol l-1 NaCl. They were isolated from the extracting media by adsorption on DEAE-Sepharose CL6B, a chromatographic agar based anion exchanger, and fractionated by chromatographic permeation on dextran gel Sephacryl S-300 yielding a low molecular weight component (between 400 and 1100 mol wt) with angiogenic and mitogenic capacities. Chromatographic behaviour and physio-chemical characteristics suggest it may be a peptide. Presence of an angiogenic and mitogenic factor in human amniochorion may explain the profuse neovascular formation and increased rate of healing obtained in the treatment of chronic ulcers by application of amniochorionic membranes as biological dressings. Preparation of purified angiogenic factor, on the other hand, opens the possibility of its wider application in the treatment of burns, open wounds and denuded areas in general.