Agarose modification on PDMS/PES composite membrane for improved hemocompatibility and anti-fouling performance

Agarose, the natural hydrophilic polysaccharide with good biocompatibility, low immunogenicity and low cost which has been widely used in tissue engineering and regenerative medicine but not in biomedical equipment, was employed to modify the potential oxygenation membrane, the core component for blood oxygenation ex vivo in the artificial lung machine. The oxidized agarose was successfully coated onto the hydrophobic polydimethylsiloxane (PDMS) surface forming a hydrophilic layer via intermolecular chemical bonding as well as physical interactions based on characterization and analyses from SEM, HNMR, FTIR, XPS and water contact angle measurement. The agarose modification significantly improved the hemocompatibility, reducing protein adsorption by 50-60 % and hemolysis rate from similar to 0.45 % to similar to 0.2 %, elongating the plasma recalcification time and blood clotting time, as well as alleviating platelet adhesion, and the antibacterial performance of the membrane, which would reduce the contamination of the membrane thus prolonging the membrane service life as well as blood clotting, blood damage and blood fouling. Meanwhile, the CO2/O-2 gas selectivity was promoted to similar to 9, an 64 % increase in comparison to that of unmodified membranes, which would significantly enhance the gas exchange efficiency of the oxygenation membrane. Moreover, the membrane modified with agarose exhibited long-term stability against platelet adhesion and blood leakage. This agarose modification strategy is simple yet effective, providing new ideas for oxygenation membrane synthesis and improvement.