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Journal for Biophysical Chemistry

Surface modification of poly(l-lactic acid) with biomolecules to promote endothelialization


Rapid endothelialization is important for biodegradable blood-contacting devices not only to prevent thrombosis but also to prevent degradation debris from entering the bloodstream and causing further complications. Here the authors report a three-step surface modification method, by which biomolecules, such as gelatin and chitosan, are covalently immobilized on the surface of plasma-treated poly(l-lactic acid) (PLLA) via —COOH groups introduced by acrylic acid grafting polymerization. Surface characterization techniques, including x-ray photoelectron spectroscopy, contact angle measurement, and colorimetric methods for surface density of functional groups, proved the feasibility and stability of this surface modification method. Surface wettability was increased by biomolecules immobilization. The —COOH surface density was measured to be 4.17±0.15 μmol/cm2, the and amount of gelatin immobilized was 4.8 μg/cm2. Human umbilical vein endothelial cell was used during in vitro study at seeding density of 104 cells/cm2. PLLA-gAA-gelatin surface was found to enhance cell adhesion, spreading, focal adhesion formation, and proliferation significantly. Chitosan-modified PLLA shows marginally improvement in cell adhesion and proliferation. Endothelialization was achieved within 7 days on both modified PLLA surfaces. In conclusion, this work demonstrates the feasibility of the surface modification method, and its ability to promote complete endothelialization for cardiovascular applications.


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Correspondence to Yun Xia.

Additional information

This paper is part of an In Focus section on Biointerphase Science in Singapore, sponsored by Bruker Optik Southeast Asia, IMRE, the Provost's Office and School of Materials Science and Engineering of Nanyang Technological University, and Analytical Technologies Pte Ltd.

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Xia, Y., Boey, F. & Venkatraman, S.S. Surface modification of poly(l-lactic acid) with biomolecules to promote endothelialization. Biointerphases 5, FA32–FA40 (2010).

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