a Composite bearing 2.99 mg of MEL-A per g of polyHEMA. The protein (1.0 mg) was added to the mixture of MEL-polyHEMA composite and 50 mM phosphate buffer (3 ml) in a polypropylene tube. The tube was incubated for 1 hr and then centrifuged. The amount of bound protein was calculated by subtracting that of unbound protein from the total added; the amount of unbound protein was estimated by measuring the UV absorbance of the supernatant. Each data is the mean of triplicate. MEL-A, mannosylerythritol lipid-A; polyHEMA, poly (2-hydroxyethyl methacylate); HIgG, human immunoglobulin G; HSA, human serum albumin.