ENHANCED ATTACHMENT AND GROWTH OF HUMAN ENDOTHELIAL-CELLS DERIVED FROM UMBILICAL VEINS ON AMMONIA PLASMA-MODIFIED SURFACES OF PTFE AND EPTFE SYNTHETIC VASCULAR GRAFT BIOMATERIALS

Ammonia plasma generated by electrical discharge at low pressure was employed for the surface modification of PTFE and ePTFE. A new chemistry at the plasma treated surfaces is reported. X-ray photoelectron spectroscopy studies showed the incorporation of C-N, C-O, C=O etc functional groups on the plasma treated surfaces. Human endothelial cells derived from umbilical veins (HUEC) were used to seed the plasma treated PTFE and ePTFE surfaces to asses the attachment and growth. Enhanced attachment and growth of HUEC was observed on the plasma treated surfaces. In addition, the performance of these surfaces in this respect was found to be considerably superior to human collagen or human fibronectin or collagen-fibronectin coated PTFE. HUEC attachment and growth on these plasma treated surfaces was further enhanced by immobilizing collagen or fibronectin or collagen-fibronectin. Ammonia plasma treated and untreated ePTFE vascular graft samples were seeded with 3.6 X 10(4) cells/sample. At 24 hrs after seeding, HUEC cell attachment was studied. Although, HUEC attachment on collagen or fibronectin coated ePTFE was improved, but there was no significant difference between the number of cells attached to these surfaces when compared with those adhered to plasma treated ePTFE without collagen or fibronectin coating. Collagen or fibronectin coated plasma treated surfaces showed better performance over their respective controls.