Research Of The Controllable Graft Modification By Polyvinylpyrrolidone On The Material Surface And Its Application

In recent yeas, the application of blood perfusion technology is becoming more and more important and great progress have made in the clinical treatment. While the adsorptive material is the core of the blood perfusion technology. Poly(styrene-divinylbenzene) porous microspheres have the advantages of high mechanical strength, moderate price, mature technology, high adsorption capacity, which has broad prospects in the applicat ion of blood perfusion. While many applications were also limited by the poor anti-protein nonspecific adsorption performance and poor blood compatibility. For the above problems, this paper selected the excellent biocompatibility of polyvinylpyrrolidone(PVP) as the graft modified molecules, the PVP was grafted on the surface of Poly(styrene-divinylbenzene) porous microspheres by thiol-ene click reaction, which improve the non-specific adsorption properties of microspheres and its blood compatibility.In this paper, the PVP with the narrow molecular weight was prepared by Reversible Addition-Fragmentation Chain Transfer Polymerization(RAFT) and then was modified by 2-aminoethanethiol to obtain PVP with terminal thiol(HS-PVP). According to the study, three kinds of HS-PVP were selected, which the weight average molecular weight were 1.52x103, 2.14x103, 3.74x103, and molecular weight distribution coefficient(PDI) were 1.22, 1.26, 1.27, respectively.Three kinds of different molecular weight of HS-PVP were used to construct the graft model, and then the influence of the graft density and the length of the grafted chain on the anti-protein adsorption properties and the biocompatibility of obtained materials were studied. The QCM-D and XPS were used to characterize and optimize the graft of HS-PVP. The samples with different graft density were obtained by controlling the time of grafting and the non-specific adsorption property and blood compatibility of the materials were enhanced with the increase of the PVP density of the material surface. The material grafted by HS-PVP2 has best anti-protein adsorption property, and the protein adsorption of the surface Au-PVP2-150 min to human blood albumin(HSA) and fibrinogen(Fg) decreased by 92.5% and 79.2%, respectively. Beside, the equilibrium adsorption of bilirubin was also improved by the graft modification of PVP and the results of computer simulation showed that the adsorption of bilirubin was realized by two conformation modes.Then the HS-PVP2 was grafted on the surface of Poly(styrene-divinylbenzene) porous microspheres by thiol-ene click reaction, and we found that with the graft quantity increase of PVP2, the adsorption capacity of microspheres for human blood albumin and fibrinogen was significantly decrease. But when the graft quantity of N was 1.25%, the hemolysis of microspheres was 1.52%, which meet clinical requirements. Poly(styrene-divinylbenzene) porous microspheres modified by the surface graft modification with polyvinylpyrrolidone can effectively improve the non-specific adsorption property and blood compatibility, which make it meet clinical requirements and show more broad application.