Technologies ranging from solvent extraction and drug delivery to tissue engineering are beginning to benefit from the unique ability of “smart polymers” to undergo controllable structural changes in response to external stimuli. The prototype is poly(N-isopropylacrylamide) (P(NIPAAm)) which exhibits an abrupt and reversible hydrophilic to hydrophobic transition above its lower critical solutio...

The influence of ethylene glycol methacrylate (EGMA) to the hydration and transition behaviors of thermo-responsive interpenetrating polymeric network (IPN) hydrogels containing sodium alginate, N-isopropylacrylamide (NIPAAm), and EGMA were investigated. The molar ratios of NIPAAm and EGMA were varied from 20:0 to 19.5:0.5 and 18.5:1.5 in the thermo-responsive alginate-Ca2+/P(NIPAAm-co-EGMA) IP...

A macromonomer 5 consisting of a polymerizable vinylcyclopropane end group and a poly(N-isopropylacrylamide) (poly(NiPAAm)) chain was obtained from amidation of 1-ethoxycarbonyl-2-vinylcyclopropane-1-carboxylic acid (4) with an amino-terminated poly(NiPAAm) 3 as an example. This macromonomer 5 showed an LCST effect after complexation of the vinyl end group with ß-cyclodextrin in water. Via radi...

The influence of long and short polymer chains on the gating properties of nanochannel systems modified with a NIPAAm-co-PBA copolymer have been explored. We not only discovered the negative temperature gating behavior of the NIPAAm modified nanochannel systems for the first time, but also achieve these two fully opposite gating behaviors (negative/positive) on the same platform.

Temperature-responsive polymers incorporating molecular-recognition sites were developed as stationary phases for high-performance liquid chromatography (HPLC). The grafted stationary phases consisted of functional copolymers composed of N-isopropylacrylamide (NIPAAm) and N-acryloyl aromatic amino acid methyl esters, i.e., phenylalanine and tryptophan methyl esters (Phe-OMe and Trp-OMe). Three ...

In this study, thermochromic photonic gels were fabricated using 2-hydroxyethyl methacrylate (HEMA) as a hydrogel building block, and 4-Acryloyl morpholine (ACMO) and N-isopropylacrylamide (NIPAAM) as thermoresponsive monomers with different critical solution temperature behaviors. Rapid photopolymerization of opal-templated monomer mixtures of varying ACMO contents formed five individual therm...

Novel poly(N-isopropylacrylamide-co-N-tert-butylacrylamide)-grafted hyaluronan [P(NIPAAm-co-NtBAAm)g-HA] has been developed as a modified derivative to improve phase-transition characteristics of PNIPAAmg-HA, which has a lower critical solution temperature (LCST) of approximately 32 ̊C. This promising selfassembling biomaterial has potential as an injectable scaffold for in situ cartilage tissue...

Background: Polymeric materials are widely known as versatile materials, particularly for biomedical applications. The bioavailability, low toxicity, solubility, and permeability of this material play an essential role in implants, such joint replacements, bone plates, ligaments, vascular grafts, intraocular lenses, heart valves, sutures, dental implants. These can be formed either biodegradabl...

We report on liquid-based tunable-focus microlens arrays made of a flexible polydimethylsiloxane (PDMS) polymer. Each microlens in the array is formed through an immiscible liquid–liquid interfacial meniscus. Here deionized water and silicone oil were used. The liquids were constrained in the PDMS structures fabricated through liquid-phase photopolymerization for molding and soft lithography. T...

Ocular drug delivery is one of the most commonly used treatment modalities in the management of glaucoma. We have recently proposed the use of gelatin and poly(N-isopropylacrylamide) (PNIPAAm) graft copolymers as biodegradable in situ forming delivery systems for the intracameral administration of antiglaucoma medications. In this study, we further investigated the influence of carrier characte...