•Poly-(sulphobetaine methacrylate) brushes and bactericidal triclosan were conjugated onto the silicon substrate.•Poly-(sulphobetaine methacrylate) brushes have strong bacterial antiadhesion properties.•The combination of a poly-(sulphobetaine methacrylate) brush with triclosan provides the surface with highly efficient antibacterial performance.In this study, a high-efficiency antibacterial surface with both antimicrobial and antiadhesive functionality was fabricated on a silicon substrate by combining a zwitterionic poly-(sulphobetaine methacrylate) (PSBMA) brush and triclosan (TCS). The uniform PSBMA polymer brush on the substrate was successfully prepared using surface-initiated atom transfer radical polymerization (SI-ATRP). A series grafting ratios of TCS was covalently conjugated to the polymer brush. The surface’s antibacterial performance was evaluated using the Actinomyces naeslundii and Escherichia coli attachment tests. Bacterial adhesion to the surface was significantly reduced following PSBMA brush modification, but the remaining bacteria on the surface were not necessarily killed. After coupling the TCS to the PSBMA brush, the surface had a high-efficiency antibacterial performance from the combination of resisting bacterial adhesion and possessing bactericidal activity.

This work presented a highly efficient antibacterial Ti-surface which was grafted with poly(N-hydroxyethylacrylamide) (PHEAA) brush and further decorated with triclosan (TCS). The modified surfaces were characterized using contact angle measurements, X-ray photoelectron spectroscopy, and attenuated total reflectance Fourier transform infrared. The antibacterial performance of the modified surfaces was evaluated using the Streptococcus mutans and Actinomyces naeslundii attachment test. The Ti surface with PHEAA brush (Ti-PHEAA) was able to resist the adhesion of the bacteria, while the TCS-decorated Ti surface (Ti-TCS) showed the capability of killing the bacteria adhered on the surface. As we coupled the TCS to the PHEAA brush, the surface showed highly efficient antibacterial performance due to the combination of the resistance to the bacteria adhesion and its activity of killing bacteria.Keywords: antibacterial surface; poly(N-hydroxyethylacrylamide); polymer brush; resistance to bacterial adhesion; surface grafting; triclosan

In this paper, a glucose and pH-responsive release system based on polymeric network capped mesoporous silica nanoparticles (MSN) has been presented. The poly(acrylic acid) (PAA) brush on MSN was obtained through the surface-initiated atom transfer radical polymerization (SI-ATRP) of t-butyl acrylate and the subsequent hydrolysis of the ester bond. Then the PAA was glycosylated with glucosamine to obtain P(AA-AGA). To block the pore of silica, the P(AA-AGA) chains were cross-linked through the formation of boronate esters between 4,4-(ethylenedicarbamoyl)phenylboronic acid (EPBA) and the hydroxyl groups of P(AA-AGA). The boronate esters disassociated in the presence of glucose or in acidic conditions, which lead to opening of the mesoporous channels and the release of loaded guest molecules. The rate of release could be tuned by varying the pH or the concentration of glucose in the environment. The combination of two stimuli exhibited an obvious enhanced release capacity in mild acidic conditions (pH 6.0).Keywords: controlled drug release; core−shell nanoparticles; glucose response; glycosylated polymer; mesoporous silica nanoparticles; pH response

A series of random copolymer brushes of acrylamide (AM) and 2-(perfluorinated hexyl)ethyl methacrylate (FMA) were grafted from initiator-functionalized silicon wafers by surface-initiated atom transfer radical polymerization. The water contact angle, X-ray photoelectron spectroscopy and atomic force microscopy were used to characterize surface wettability, surface composition, and morphology of the surfaces modified with polymer brushes, respectively. The protein-resistance performance of the surfaces grafted with polymer brushes was evaluated using micro-BCA protein assay reagent. It was found that the random copolymer brushes with the optimal ratio of AM to FMA in monomers showed the best protein-resistance performance, however, the optimal ratio is different for resisting bovine serum albumin and human plasma fibrinogen adsorption. For resisting bovine serum albumin adsorption, the optimal ratio of AM to FMA in monomers is 1:3, while the optimal is 3:1 for human plasma fibrinogen adsorption resistance. The results provide further evidence that surface compositional heterogeneities and microphase segregation of fluorinated moieties of amphiphilic random copolymer brushes significantly impact protein adsorption behaviors.

A drug delivery system of dual-stimulated release of size-selected cargos from β-cyclodextrin-covered mesoporous silica nanoparticles was prepared. Calcein loaded mesoporous silica nanoparticles (MSN) were capped by β-cyclodextrin (β-CD) through photocleavable moieties to control its release. Then the small size cargo p-coumaric acid (CA) was loaded. The cavity of β-cyclodextrin was blocked by ferrocene through the host–guest interaction between the ferrocene and β-cyclodextrin. The small cargo can be released by the escape of ferrocene under +1.5 V electro-stimuli. Calcein molecules could not pass through the cavity of the β-cyclodextrin due to its bigger size. The calcein was released from the MSN after the detachment of the β-cyclodextrin cap from the MSN surface with UV irradiation. Fluorescence spectra demonstrate that different sized cargoes were released successfully step by step under external UV-light and electro stimuli respectively.