Surface modification of ultrahigh molecular weight polyethylene by the poly(ethylene glycol)‐grafted method and its effect on the adsorption of proteins and the adhesion of blood platelets

Abstract

With the help of a silane coupling agent, poly(ethylene glycol) (PEG), a well-biocompatable agent, was grafted onto the surface of ultrahigh molecular weight polyethylene (UHMWPE) by ultraviolet initiation. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis proved the success of PEG grafting. Water contact angle measurement showed that the modified UHMWPE was obviously improved in surface hydrophilicity and thermogravimetric analysis result showed that its thermostability did not decline even it was pretreated by strong acids. Then, the protein adsorption of the modified UHMWPE was investigated using three model proteins including bovine serum albumin, lysozyme, and fibrinogen. Rabbit blood was used to study the platelet adhesion on the surface of modified UHMWPE. The results indicated that the quantity of protein adsorption on the modified UHMWPE grafted PEG reduced apparently for all the model proteins while there was some specific differences or exceptions among them. It was ascribed to the changed surface chemical composition, surface hydrophilicity and surface topography after modification. The adhesive ability of blood platelets on the modified surface of UHMWPE decreased after PEG grafting. Owing to the improved resistance to fibrinogen adsorption and platelet adhesion, the surface modification might endow the UHWMPE surface better anticoagulation ability according to clotting mechanism.

Surface modification of ultrahigh molecular weight polyethylene by plasma‐induced in‐situ grafting with vinyl triethoxysilane

“…As demonstrated in Figure , the sample after plasma‐induced grafting and hydrolysis has almost the same TG and DTG curves as the virgin one, which shows that their thermal stability should be the same. The results of XRD, as shown in Figure , corroborate the aggregate structure of UHMWPE sheet almost remains unchanged after plasma‐induced grafting, whether on the surface or in the substrate.…”

“…Moreover, plasma treatment gives rise to the contents of C=O (288.0 eV) and C–O (286.5 eV), as shown in Figure d. And the peak at 284.5 eV could be regarded as the combination of C–C and C–Si bond, for the two peaks are too similar to be distinguished by software …”

“…The common ways to deal with this problem include oxidation treatment, radiation‐induced graft, and plasma treatment . In the case of plasma treatment, usually a very thin layer of surface in nanometer scale is involved, and the bulk structure and the intrinsic property would remain unchanged.…”

“…In fact, the grafted alkoxysilanes can also improve the surface hydrophilicity of polyethylene and the hydroxyl groups are also active sites for many reactions other than condensation. In our previous work, polyethylene glycol was grafted onto the surface of UHMWPE with the help of grafted vinylsilane by ultraviolet initiation, which improved the biocompatibility of UHMWPE . In this article, emphasis was played on the method of grafting VTEOS on UHMWPE surface efficiently by air plasma treatment.…”

Modification of polyglycolic acid and poly lactic-co-glycolic acid fibers by ultrasonic treatment for enhancing hydrophilicity and cytocompatibility

“…Compared with the crystallization degree measured by XRD, crystallization degree measured by DSC analysis had a little difference in number value. This status had been reported in some literature [19]. It is due to limitations of test methods or error of data.…”