Poly(N-isopropylacrylamide)-modified silica beads with hyperbranched polysiloxysilane for three-dimensional cell cultivation

Abstract

The immobilization of poly(N-isopropylacrylamide) (PNIPAM) onto the surface of silica beads via hyperbranched polysiloxysilane (HBPS) was studied to develop a new material for cell cultivation. HBPS terminated with a vinyl functional group was synthesized by self-polymerization of an AB 2 monomer. The terminal vinyl group was converted into a chain-transfer agent for reversible addition fragmentation chain transfer (RAFT) polymerization. The obtained HBPS was immobilized on the silica surface by mixing silica beads and HBPS in hexane. The graft polymerization of PNIPAM onto the silica surface was achieved using RAFT polymerization. The molecular weights of the grafted polymers obtained by cleavage from the surface of silica beads using NaOH aqueous solution were in the range of 6000-23 000 and the polydispersity index values were 1.4-1.6. The grafted silica beads have been tested for cell cultivation. Silica-HBPS-g-PNIPAM with a higher molecular weight (M n ) of PNIPAM (cleaved PNIPAM M n ¼ 14 800 and 23 700) showed a thermo-reversible phase transition at approximately 34 1C, and controlled cell adhesion and detachment was demonstrated with these beads.

Synthesis of naringin‐based polymer brushes via seATRP

“…In order to determine the side chain lengths of synthetized flavonoid‐based homopolymer and copolymer macromolecular brushes, each arm was cleaved off the naringin core by an alkaline ester hydrolysis . Cleavage was a verified by THF GPC (Figure S6).…”

“…The side chains of the naringin-based (co)polymer brushes were cleaved off by an alkaline ester hydrolysis according to the procedure described in the literature. [121][122][123][124] In a typical experiment, brush (co)polymer sample was dissolved in THF, after which MeOH and 3 M NaOH were added. The mixture was transferred to a capped vial and placed in an oil bath heated at 98°C for 10 days.…”

Preparation of hyperbranched polystyrene-g-poly(N-isopropylacrylamide) copolymers and its application to novel thermo-responsive cell culture dishes

“…The molecular weight of P1 was M n ¼ 7.0 Â 10 3 and M w /M n ¼ 2.76. As illustrated in Scheme 2, P1 was converted into P2, P3 and P4 through the reaction with sodium azide [19], introducing CTA, and RAFT polymerization of N-isopropylacrylamide (NIPAM) [9], respectively. An azide group, which is the reactive group for the click reaction, was introduced by a simple replacement reaction of the chlorine atom of P1 using sodium azide to form P2.…”

“…HBPSt-g-PNIPAM (P4) was prepared by the reversible addition fragmentation chain transfer (RAFT) polymerization of NIPAM from P3 (Scheme 2) [9]. For example, P3-33 (35 mg, 0.0157 mmol of CTA segment), NIPAM (0.28 g, 2.74 mmol), AIBN (1 mg), and dry THF (1.5 mL) were added into a 5-mL ampule vial and degassed by the freezeepumpethaw cycle three times.…”

Surface modification by deposition of IPA plasma and gellan gum/chitosan hybrid hydrogel onto thermoplastic polyurethane for controlled release of N‐acetylcysteine

“…Therefore, plasma technologies (polymerization, glow, corona, photografting, and UV‐induced graft) have been used to modify the surface of TPU. Utilizing peroxides (·OH, ·OOH ..), free radicals, and functional groups (–NH 2 , –COOH, ·C=O, –OH ..) is a very efficient method to promote hydrophilicity of the TPU surface, introduced by plasma or grafting of gas or monomers such as air, Ar, N 2 , O 2 , He, CH 4 , acrylic acid(AAc), acetic acid(AA), isopropyl alcohol(IPA), N‐isopropylacrylamide (NIPAAm), and hexamethyldisilazane (HMDSZ). Grafting of gellan gum/chitosan hybrid gels, a three‐dimensional network hydrophilic polymer featuring wettability, swelling phenomena, and sensitivities (temperature, pH), onto the TPU membrane surface was accomplished by PECVD.…”