A new concept in chromatography is proposed that utilizes a temperature-responsive surface with constant aqueous mobile phase. The of the silica stationary phase high-performance liquid (HPLC) has been modified polymers to exhibit temperature-controlled hydrophilic/hydrophobic changes. Poly(N-isopropylacrylamide) (PIPAAm) was grafted onto (aminopropyl)silica using an activated ester-amine coupling method. These surfaces show hydrophilic properties at lower temperatures which, as temperature...

We recently reported the new concept of temperature-responsive liquid chromatography using poly(N-isopropylacrylamide)-modified surfaces as high-performance media with aqueous mobile phases. Incorporation hydrophobic sites is an important factor to improve efficacy (selectivity and retention) chromatography. Toward this goal, we have synthesized semitelechelic copolymers N-isopropylacrylamide (IPAAm) butyl methacrylate (BMA) having reactive terminal functional groups telomerization. The...

We have prepared various poly(N-isopropylacrylamide) (PIPAAm)-grafted silica bead surfaces through surface-initiated atom transfer radical polymerization (ATRP) by changing graft densities and brush chain lengths. The were characterized chromatographic analysis using the modified beads as stationary phases. ATRP initiator (2-(m,p-chloromethylphenyl)ethyltrichlorosilane) density on was modulated feed composition of self-assembled monolayers (SAMs) mixed silane coupling agents consisting...

Dense poly(N-isopropylacrylamide) (PIPAAm) brushes were created on silica bead surfaces by surface-initiated atom transfer radical polymerization (ATRP). Interfacial properties of PIPAAm characterized thermoresponisve interaction with biomolecules. The grafted amounts exceeded that from previously reported polymer-hydrogel-modified beads prepared conventional nearly 1 order magnitude. Temperature-dependent chromatographic interactions soluble analytes modulated changing the chain lengths....

Recently, green chemistry has become one of the most important subjects science for environmental pollution prevention. Here, we report development a novel chromatographic technology phenylthiohydantoin (PTH)−amino acid analyses in which only aqueous solution is used as mobile phase. We have devised HPLC adsorbents (stationary phase) by modifying surfaces microparticulate silica gel using functional polymers. The thermoresponsive copolymer, poly(N-isopropylacrylamide-co-n-butyl methacrylate)...

We have prepared poly(N-isopropylacrylamide (IPAAm)-co-2-(dimethylamino)ethylmethacrylate (DMAEMA)) brush-grafted silica bead surfaces through surface-initiated atom transfer radical polymerization (ATRP) using the CuCl/CuCl2/Me6TREN catalytic system in 2-propanol at 25 °C for 16 h. The temperature-responsive were characterized by chromatographic analysis modified beads as stationary phases. Chromatographic retention times adenosine nucleotides aqueous mobile phases significantly increased...

The scavenging reaction of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) or galvinoxyl (GO˙) by a vitamin E model, 2,2,5,7,8-pentamethylchroman-6-ol (1H), was significantly accelerated the presence Mg(ClO4)2 in de-aerated methanol (MeOH). Such an acceleration indicates that radical-scavenging 1H MeOH proceeds via electron transfer from to radical, followed proton transfer, rather than one-step hydrogen atom which has been observed acetonitrile (MeCN). A significant negative shift...

Poly(N-isopropylacrylamide) (PNIPAAm)-based temperature-responsive fluorescence polymer probes were developed using radical polymerization, with 3-mercaptopropionic acid as the chain-transfer agent, followed by activation of terminal carboxyl groups N-hydroxysuccinimide and reaction 5-aminofluorescein (FL). The lower critical solution temperatures (LCSTs) resulting fluorescent differed depending on copolymer composition, had a sharp phase-transition (hydrophilic/hydrophobic) boundary at...

Abstract Background In most stem cell therapy strategies reported to date, cells are introduced damaged tissue sites repair and regenerate the original structure function. MSC therapeutic efficacies inconsistent, largely attributed transplanted difficulties both in engrafting at retaining their functions from suspension formulations. functional components, including adhesion cell–cell junction proteins, ECM that contribute essential cellular effects, or removed by proteolytic enzymes used...

Small interfering RNAs (siRNAs) have been attracting significant attention owing to their gene silencing properties, which can be utilized treat intractable diseases. In this study, two temperature-responsive liposomal siRNA carriers were prepared by modifying liposomes with different polymers-poly(N-isopropylacrylamide-co-N,N-dimethylaminopropyl acrylamide) (P(NIPAAm-co-DMAPAAm)) and poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) P(NIPAAm-co-DMAAm). The phase transition of...

During the last few decades, thermoresponsive materials for modulating cell adhesion have been investigated application of tissue engineering. In this study, we developed mixed polymer brushes consisting poly(N-isopropylacrylamide) (PNIPAAm) and poly(N,N-dimethylaminopropylacrylamide) (PDMAPAAm). The were prepared on a glass substrate via reversible addition-fragmentation chain transfer polymerization DMAPAAm subsequent atom radical NIPAAm. grafted to exhibited increased cationic properties...

Abstract Thermoresponsive surfaces are prepared via a spin‐coating method with block copolymer consisting of poly( N ‐isopropylacrylamide) (PIPAAm) and poly(butyl methacrylate) (PBMA) on polystyrene surfaces. The PBMA suppresses the removal deposited PIPAAm‐based polymers from surface. polymer coating affects temperature‐dependent cellular behavior respect to protein adsorption. By adjusting layer thicknesses, ‐b‐ PIPAAm‐coated optimized regulate adhesion/detachment cells by temperature...

Thermo-responsive chromatography matrices with three types of graft architecture were prepared, and their separation performance stability for continuous use investigated. Poly(N-isopropylacrylamide)(PIPAAm) hydrogel-modified silica beads prepared by a radical polymerization through modified 4,4′-azobis(4-cyanovaleric acid) N,N′-methylenebisacrylamide. Dense PIPAAm brush-grafted dense poly(N-tert-Butylacrylamide (tBAAm)-b-IPAAm) surface-initiated atom transfer (ATRP) using CuCl/CuCl2/...

We report the development of environmentally responsive fluorescent polymers. The reversible temperature-induced phase transition copolymers composed N-isopropylacrylamide and a monomer based on fluorescein (FL), coumarin (CO), rhodamine (RH), or dansyl (DA) skeleton was used as molecular switch to control fluorescence intensity. poly(N-isopropylacrylamide) (PNIPAAm) chain showed an expanded coil conformation below lower critical solution temperature (LCST) due hydration, but it changed...

L-type amino acid transporter 1 (LAT1) is a that more highly expressed in cancer cells compared with normal cells. In the present study, liposomes, composed of egg phosphatidylcholine (EPC) and dioleoyl phosphatidylethanolamine, were modified LAT1-targeting thermoresponsive polymer, l-tyrosine-conjugated poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) (P(NIPAAm-co-DMAAm)). The cellular uptake prepared liposomes was evaluated using HeLa as cell model. At temperatures above polymer's...