Photoreactive Polymers Bearing a Zwitterionic Phosphorylcholine Group for Surface Modification of Biomaterials

Abstract

Photoreactive polymers bearing zwitterionic phosphorylcholine and benzophenone groups on the side chain were synthesized and used as surface modification reagents for biomaterials. A photoreactive methacrylate containing the benzophenone group, 3-methacryloyloxy-2-hydroxypropyl-4-oxybenzophenone (MHPBP), was synthesized via a ring-opening and addition reaction between glycidyl methacrylate and 4-hydroxybenzophenone. Then, water-soluble, amphiphilic polymers poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-MHPBP) (PMH) and poly(MPC-co-n-butyl methacrylate-co-MHPBP), with different monomer unit compositions, were synthesized through radical polymerization. Ultraviolet-visible (UV/vis) absorption spectra of these polymer solutions showed that these polymers have maximum absorption peaks at 254 and 289 nm that can be attributed to the benzophenone unit. The intensity of UV adsorption at 289 nm was decreased with increased UV irradiation time, and it was saturated within a few minutes, indicating that the polymers are highly sensitive to UV irradiation. A commercial material (i.e., cyclic polyolefin) was simply modified by a UV irradiation for 1.0 min. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis results indicated that the stability of the polymer on the surface was dramatically enhanced because of the photochemical reaction of the benzophenone moiety. The air contact angles of PMH surfaces measured in water were up to 160°. Thus, highly hydrophilic surfaces were obtained. The critical surface tension of the PMH-modified surface was 45.7 mN/m. By evaluating the biological reactivity of the treated surface, protein adsorption and cell adhesion were completely inhibited on the surface, which was prepared using a photopatterning procedure using PMH. In conclusion, photoreactive MPC polymers with a benzophenone moiety could be used as a novel and effective surface modifier.

Surface Modification by Polyzwitterions of the Sulfabetaine-Type, and Their Resistance to Biofouling

“…The spin-coated films were stabilized by irradiation with near-UV light (Figure 4). This gives rise to simultaneous covalent cross-linking of the chains and covalent attachment to the support due to the specific photochemical reactivity of the benzophenone moiety [52,53,65,66,67,68,69,70,71], overcoming the need for incorporating two different reactive groups in the hydrogel film forming polymer [72,73]. With its spectral cut-off at 310 nm, the irradiation system chosen excites only the flank of the intense absorbance band centered at about 295 nm of the 4-alkoyxy benzophenone chromophore (Figure 4a).…”

Zwitterionic poly-carboxybetaine coating reduces artificial lung thrombosis in sheep and rabbits

“…This may also be due to the challenges of scaling up the ARGET-ATRP methodology to larger, more complex surfaces compared to smaller, simpler surfaces tested in previous studies [16]. Finally, the random copolymerization approach has been used for physiosorption of highly hydrophilic zwitterionic polymers to hydrophobic surfaces [23,27]. This method is the most established and often utilized for commercial coatings, but its effectiveness may depend on the substrate surface.…”

“…The sample was incubated with this solution and then agitated for 20 hours. ii) Random Copolymer: CB random copolymers, poly(CBAA-co-BMA) and poly(CBAA-co-MTS-co-TMAEMA) were synthesized by conventional free radical polymerization method using AIBN as an initiator, in a method similar to that reported previously [22][23][24]. In brief, the desired amounts of monomer and AIBN were dissolved into ethanol.…”

Ultralow Fouling and Functionalizable Surface Chemistry Based on Zwitterionic Carboxybetaine Random Copolymers

“…Poly(MPC- co-n-butyl methacrylate (BMA)) with ~30 mol% of hydrophilic unit has been applied to many surfaces of medical devices with excellent biocompatibility. 31,34–35 However, comprehensive investigations of CB random copolymers are still lacking up to now. Furthermore, their capability for the surface functionalization of terminal carboxyl groups makes them an attractive surface modification material.…”