Brush-modified silica hybrids have been synthesized by growing poly(2-(diethylamino)ethyl methacrylate) (poly(DEA)) brushes on 120 nm diameter silica particles by surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP). This is the first report of using SI-ARGET ATRP to synthesize poly(DEA) brushes. The kinetics of poly(DEA) brush growth in 4:1 v/v ethanol/water was monitored. The hydrodynamic diameter of the resulting brush-modified particles was dependent on the solution pH due to the weak polybasic nature of the brushes. Below the p of poly(DEA), the hydrodynamic diameter of the brush-modified particles increased with decreasing pH as a consequence of brush protonation, rearrangement and solvent uptake. This pH-response of the brushes was reversible and the hybrid particles exhibited significant hydrodynamic volume changes of up to 200% when the solution pH was cycled from pH 7 to pH 4.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/mz3003566 | DOI Listing |
Heliyon
August 2024
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato, Tokyo, 105-8512, Japan.
Thermoresponsive polymer brushes have attracted considerable research attention owing to their unique properties. Herein, we developed silica beads grafted with poly(-isopropylacrylamide (NIPAAm)--3-acrylamidopropyl trimethylammonium chloride (APTAC)---butyl acrylamide (tBAAm) and P(NIPAAm--APTAC---butyl methacrylate(nBMA)) brushes. The carbon, hydrogen, and nitrogen elemental analysis of the copolymer-grated silica beads revealed the presence of a large amount of the grafted copolymer on the silica beads.
View Article and Find Full Text PDFMacromol Biosci
August 2023
Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, Aarhus, 8000, Denmark.
The immobilization of enzymes on solid supports is an important challenge in biotechnology and biomedicine. In contrast to other methods, enzyme deposition in polymer brushes offers the benefit of high protein loading that preserves enzymatic activity in part due to the hydrated 3D environment that is available within the brush structure. The authors equipped planar and colloidal silica surfaces with poly(2-(diethylamino)ethyl methacrylate)-based brushes to immobilize Thermoplasma acidophilum histidine ammonia lyase, and analyzed the amount and activity of the immobilized enzyme.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
December 2022
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato, Tokyo 105-8512, Japan.
Adipose-derived mesenchymal stem cells (ADSCs) have beneficial effects in cell transplantation therapy; these cells are collected from adipose tissue using low-invasive methods. However, to prepare ADSCs for cell therapy, a cell separation method that neither involves modification of the cell surface nor causes loss of cell activity is needed. Here, we aimed to develop ADSC separation columns using thermoresponsive cationic block copolymer brush-grafted beads as packing materials.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2022
Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, China.
The elevated concentration of low-density lipoprotein (LDL) is recognized as a leading factor of hyperlipidemia (HLP), and selective adsorption of serum LDL is regarded as a practical therapy. Based on the superior structure-function characteristics of stimuli-responsive materials, a photorenewable nanoadsorbent (SiO@Azo@Gly) with high selectivity and reusability was developed using azobenzene as the functional ligand. Its principle was certified by the preparation of silicon nanoparticles with atom transfer radical polymerization (ATRP)-initiating groups via a sol-gel reaction and their subsequent grafting of azobenzene polymer brushes by surface-initiated ATRP, followed by modification with glycine.
View Article and Find Full Text PDFSci Rep
March 2022
Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato, Tokyo, 105-8512, Japan.
In this study, mixed-mode chromatography columns have been investigated using multiple analyte interactions. A mixed-mode chromatography column was developed using poly(N-isopropylacrylamide) (PNIPAAm) brush-modified silica beads and poly(3-acrylamidopropyl trimethylammonium chloride) (PAPTAC) brush-modified silica beads. PNIPAAm brush-modified silica beads and PAPTAC brush-modified silica beads were prepared by atom transfer radical polymerization.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!