Optimization of the composition of zwitterionic copolymers for the easy-construction of bio-inactive surfaces

Abstract

Random copolymers (S-PCMBx) of the zwitterionic monomer carboxymethylbetaine (CMB) and a small percentage of 3-methacryloyloxypropyl trimethoxysilane with various composition ratios were synthesized in ethanol using 2,2'-azobisisobutyronitrile as the initiator. An S-PCMBx layer formed on the glass substrate after soaking in the copolymer solution and had a thickness of 2-3 nm. The S-PCMBx-modified surface was highly hydrophilic and suppressed both the non-specific adsorption of protein (bovine serum albumin) and NIH3T3-fibroblast adhesion. The degree of adsorption suppression increased with increasing copolymer CMB content with a maximum at 90 mol % CMB. In contrast, the modification of the glass substrate with a PCMB homopolymer terminally modified with a trimethoxysilyl group did not effectively suppress protein adsorption and cell adhesion due to the low graft density. The importance of balancing the number of fixation points and the length of the zwitterionic polymer loops to produce bio-inactive metal oxide surfaces is suggested. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2029-2036, 2016.

The cytotoxic effect of TiF4 and NaF on fibroblasts is influenced by the experimental model, fluoride concentration and exposure time

“…NIH/3T3 has been widely applied in cell culture for several decades, including tests of cell viability and toxicity of biomaterials used in Dentistry as it can be used as a substitute for human gingival fibroblasts [24,25]. …”

UV‐Patterning of Anti‐Biofouling Zwitterionic Copolymer Layer with an Aromatic Anchor Group

“…BSA was extremely adsorptive to the UV‐irradiated copolymer‐modified glass (Figure ), which could be attributed to the hydrophobic interaction between the protein and the substrates. According to previous studies, the adsorption of both a positively charged protein (lysozyme pI 11.0) and a negatively charged protein (BSA pI 4.5–5.0) was not significant on the poly(CMB‐ r ‐MPTMS) layer, indicating the crucial role of zwitterionic side groups in suppressing the protein adsorption. A similar tendency could be expected in the case of poly(CMB‐ r ‐STMS).…”

“…The polymer layer exhibited a slight nonspecific adsorption upon mixing with BSA (pI 4.5–5.0) solution, in contrast with the significant adsorption of the protein on the UV‐irradiated copolymer‐modified surfaces (Figure ). Among the copolymers composed of various ratios of CMB and MPTMS, the copolymer prepared with 90 mol% CMB was reported to exhibit the highest resistance to protein adsorption …”

“…In contrast to the polymer brush system, the copolymer layer exhibited a thickness of around 2 nm, which enabled the complete removal of the copolymer layer with the UV irradiation. In particular, a pattern in an area of 1.5 × 1.5 µm could be clearly observed upon irradiation at 500 mJ cm −2 on the poly(CMB‐ r ‐STMP) layer‐modified wafer surface (Figure ), exhibiting a higher contrast than that observed with the poly(CMB‐ r ‐MPTMS) layer.…”

“…In this study, a carboxymethylbetaine copolymer layer‐modified glass substrate has been prepared by a simple silane coupling reaction of a random copolymer of CMB and p ‐trimethoxysilylstyrene (STMS) on a glass substrate and a silicon wafer (Scheme S1b, Supporting Information). An optimum molar ratio of 9:1 in the formation of copolymers of CMB and 3‐methacryloxypropyltrimethoxysilane (MPTMS) was reported for ensuring efficient suppression of the nonspecific adsorption and adhesion of proteins and cells . Hence, we prepared a copolymer of CMB and STMS, respectively using a molar ratio of 9:1, and the resistance to the nonspecific adsorption of protein on the copolymer layer surface was compared with that on the poly(CMB‐ r ‐MPTMS) (9:1) surface.…”