Interactions between protein coated particles and polymer surfaces studied with the rotating particles probe.

Nonspecific interactions between proteins and polymer surfaces have to be minimized in order to control the performance of biosensors based on immunoassays with particle labels. In this paper we investigate these nonspecific interactions by analyzing the response of protein coated magnetic particles to a rotating magnetic field while the particles are in nanometer vicinity to a polymer surface. We use the fraction of nonrotating (bound) particles as a probe for the interaction between the particles and the surface.

Polyurethanes based on dihydroxamic acids. Synthesis, chemical characterization, and biological activity.

A series of segmented polyurethanes based on polyethylene oxide/polycaprolactone diol, isophorone diisocyanate, and dihydroxamic acids were synthesized and characterized. Biocompatibility and antitumoral activity were in vivo tested on Wistar male rats and Wistar rats affected with Walker 256 carcinosarcoma, respectively. The effect of dihydroxamic acid structure on the biological properties was determined.

Biological activity of maleic anhydride copolymers. I. Biocompatibility and antitumoural effects of maleic anhydride-vinyl acetate, maleic anhydride-methyl methacrylate and maleic anhydride-styrene copolymers.

A series of maleic anhydride (MA)-vinyl acetate (VA), MA-methyl methacrylate (MM), and MA-styrene (S) copolymers were prepared and characterized. On employing various amounts of initiator, maleic anhydride-vinyl acetate, methyl methacrylate, and styrene copolymers with molecular weights ranging between 18,000 and 200,000 have been obtained. The in vivo and in vitro tests performed on K562 cellular cultures (human chronic myeloid leukemia) have shown that, as a function of the molecular weight, the synthesized copolymers demonstrate a 50% in vitro cytotoxicity and an average tumour regression of maximum 68%.