Developing a facile but efficient anti-fouling surface coating is highly required for metallic implants. Here, we report two kinds of zwitterionic copolymers (both random and block) bearing phosphonic/phosphonate motifs/segments as novel metal anchorable antifouling coatings. Through conventional free radical polymerization and reversible addition–fragmentation chain transfer (RAFT) polymerization, three types of zwitterionic–phosphonic random copolymers with varying mol. ratios (9 : 1, 8 : 2, and 6 : 4) and a phosphonate-zwitterionic block copolymer were precisely prepared based on zwitterionic sulfobetaine methacrylate (SBMA) and phosphonate/phosphonic methacrylate. As evidenced by XPS and water contact angle tests, the two kinds of copolymers with distinguished presenting manners of the metal-anchorable phosphonate/phosphonic motifs were all successfully immobilized on the Ti substrates through a facile one-step post-functionalization. The immobilized copolymers equally exhibited strong inhibition of protein adsorption, platelet adhesion, and bacterial adhesion, endowing significantly improved antifouling ability to the metallic substrates. This work not only provides a novel approach to improve the antifouling ability of Ti substrates, the utilization of phosphonic/phosphonate based copolymers as efficient metal-anchorable coatings may offer a new platform for versatile surface functionalization of many metallic substrates.

•Different levels of theory were compared.•Effective conjugation coordinate (ECC) mode was best reproduced by the two levels.•It was reconfirmed that the TD-DFT method would systematically underestimate the excitation energy of 38.60–67.54 kJ mol−1.•The B3LYP level may be a proper choice for theoretically study of Raman spectrum about polyene conjugated systems.The conformational space of the all-trans retinal deprotonated Schiff base (DSBT) molecule around its four internal backbone torsional angles was studied. A total of eight different conformers were detected from potential energy surface exploration corresponding to the four internal backbone torsional angles. The standard split-valence 6-311++G(d,p) basis set in combination with MP2 and B3LYP levels were carried out to analyze the structural characteristics (relative energies, dipole moments and bond length alternation) and spectral properties (electronic absorption spectrum and Raman spectrum) of the conformers. Results presented in this paper showed that the relative stability order of the conformers might be independent of the level of theory used. It was also reconfirmed that the TD-DFT method would systematically underestimate the excitation energy by 38.60–67.54 kJ mol−1; a trend had been reported in several previous studies. The characteristic peak nearby 1600 cm−1 corresponding to the ECC mode could be notably observed from the predicted Raman spectrum calculated at both the MP2 and the B3LYP level of theories. Moreover, the spectral profile acquired based on the B3LYP level was more apparent and distinguishable than that from the MP2 method. It is suggested that B3LYP level may be a proper choice for theoretically study of Raman spectrum, especially concerning the polyene conjugated systems.The photoactivation mechanism of rhodopsin.

•We first used self-polymerized dopamine to form a thin and surface-adherent polydopamine layer onto PET film.•Then, DMDA was attached to the PET surface by Michael addition.•Sulfobetaine and carboxybetaine were finally constructed through ring-opening reaction.•The modify PET endowed with improved resistance to nonspecific protein adsorption and platelet adhesion.Poly (ethylene terephthalate) (PET) has been widely adopted as a scaffold biomaterial, but further hemocompatibility improvement is still needed for wide biomedical applications. Inspired by the composition of adhesive proteins in mussels, we propose to use self-polymerized dopamine to form a surface-adherent polydopamine layer onto PET sheet, followed by Michael addition with N,N-dimethylethylenediamine (DMDA) to build tertiary amine, and final zwitterions(sulfobetaine and carboxybetaine) construction through ring-opening reaction. Physicochemical properties of substrates were demonstrated by water contact angle measurement, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The hemocompatibility was evaluated by platelet adhesion, hemolytic, and protein adsorption. The results showed that the zwitterions immobilized PET endowed with improved resistance to nonspecific protein adsorption and platelet adhesion as well as nonhemolytic. The zwitterions with desirable hemocompatibility can be readily tailored to catheter for various biomedical applications.

Two major complications generally occur in blood-contacting devices, namely thrombus formation and microbial invasion and infection. Therefore, hemocompatible and antibiofouling surfaces, which function as barriers to bacterial and cell adhesion, are essential. Herein, we report the successful grafting of zwitterionic polysulfobetaine brushes onto a cellulose membrane (CM) via surface-initiated reversible addition–fragmentation chain-transfer (SI-RAFT) polymerization for improving hemocompatibility and antibiofouling property. Both pristine and polysulfobetaine brush-modified CM substrates were characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements (WCA), X-ray photoelectron spectroscopy analysis (XPS), and atomic force microscopy (AFM). Experimental observations demonstrated the successful grafting of polysulfobetaine brushes, where brush thicknesses were found to increase gradually with polymerization time and monomer concentrations. Tests conducted by investigating platelet adhesion, hemolytic rates and protein adsorption indicated that polysulfobetaine brush-grafted CMs had excellent hemocompatibility featuring lower platelet adhesion and protein adsorption properties without causing hemolysis. E. coli adhesion and HeLa cell adhesion tests showed that grafted CMs had superior antibacterial adhesion properties and long-term cell adhesion resistance for up to four days. The functionalized cellulose substrate described holds great potential for use in biomedical applications.

Grafting-from has proven to be a very effective way to create high grafting densities and well-controlled polymer chains on different kinds of surfaces. In this work, we aim to graft zwitterionic brush from cellulose membrane (CM) via ARGET-ATRP (Activator Regenerated by Electron Transfer ATRP) method indirectly for blood compatibility improvement. Characterization of the CM substrates before and after modification was carried out by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements, X-ray photoelectron spectroscopy analysis, and atomic force microscopy, respectively. The results demonstrated zwitterionic brushes were successfully grafted on the CM surfaces, and the content of the grafted layer increased gradually with the polymerization time. The platelet adhesion, hemolytic test and plasma protein adsorption results indicated the cellulose membrane had significantly excellent blood compatibility featured on lower platelet adhesion and protein adsorption without causing hemolysis. The functionalized cellulose substrate could have a great potential usage for biomedical applications.Graphical abstractIn this work, we aim to graft zwitterionic brush from cellulose membrane (CM) via ARGET-ATRP (Activator Regenerated by Electron Transfer ATRP) method indirectly for blood compatibility improvement. Characterization of the CM substrates before and after modification was carried out by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements, X-ray photoelectron spectroscopy analysis, and atomic force microscopy, respectively. The platelet adhesion, hemolytic test and plasma protein adsorption results indicated the cellulose membrane had significantly excellent blood compatibility featured on lower platelet adhesion and protein adsorption without causing hemolysis.Highlights► Carboxybetaine brush was grafted onto cellulose surface via surface-initiated ARGET ATRP for improving blood compatibility ► Cellulose membrane had significantly excellent blood compatibility featured on lower platelet adhesion and protein adsorption without causing hemolysis. ► Cellulose membrane could have a great potential usage for biomedical applications.

In order to improve blood compatibility of polyethylene (PE) film, the Pluronics F127 additives in the PE film were then crosslinked to be stably entrapped in the PE matrix. The crosslinking was done by free radicals produced from the decomposition of dicumyl peroxide (DCP) in the film through heating (120 °C). Surface properties of the Pluronics F127 additive-containing PE films were investigated by Fourier transform infrared spectroscopy (FTIR), electron spectroscopy for chemical analysis (ESCA) and water contact angle (WCA) measurements. The blood compatibility of the Pluronics F127 additive-containing films was evaluated by platelet-rich plasma and blood-cell adhesion tests, respectively. And the results were observed by scanning electron microscopy. The blood compatibility of the prepared Pluronics F127 additive-containing film is better than that of blank PE film. These results suggest that the blood compatibility of Pluronics F127 additive-containing films make them suitable biomaterials for some applications.

Developing a facile but efficient anti-fouling surface coating is highly required for metallic implants. Here, we report two kinds of zwitterionic copolymers (both random and block) bearing phosphonic/phosphonate motifs/segments as novel metal anchorable antifouling coatings. Through conventional free radical polymerization and reversible addition–fragmentation chain transfer (RAFT) polymerization, three types of zwitterionic–phosphonic random copolymers with varying mol. ratios (9:1, 8:2, and 6:4) and a phosphonate-zwitterionic block copolymer were precisely prepared based on zwitterionic sulfobetaine methacrylate (SBMA) and phosphonate/phosphonic methacrylate. As evidenced by XPS and water contact angle tests, the two kinds of copolymers with distinguished presenting manners of the metal-anchorable phosphonate/phosphonic motifs were all successfully immobilized on the Ti substrates through a facile one-step post-functionalization. The immobilized copolymers equally exhibited strong inhibition of protein adsorption, platelet adhesion, and bacterial adhesion, endowing significantly improved antifouling ability to the metallic substrates. This work not only provides a novel approach to improve the antifouling ability of Ti substrates, the utilization of phosphonic/phosphonate based copolymers as efficient metal-anchorable coatings may offer a new platform for versatile surface functionalization of many metallic substrates.