Biomaterial Database

Effect of thermal cycling on the properties of thermoresponsive poly(N-isopropylacrylamide) hydrogels. 2003

Sai Kit Li, and Antony D'Emanuele

School of Pharmacy & Pharmaceutical Sciences, University of Manchester, Manchester, M13 9PL, UK.

Crosslinked poly(N-isopropylacrylamide) hydrogels have been widely studied for a variety of thermoresponsive applications, including chromatography, affinity precipitation, controlled biocatalysis, viable cell immobilisation, biomimetic actuators and, in particular, modulated drug delivery. The exploitation of crosslinked poly(N-isopropylacrylamide) hydrogels in all these applications relies on the well-known temperature-sensitive swelling properties of these hydrogels. The purpose of the current study was to determine the effects of repeated thermal cycling on the thermoresponsive swelling behaviour of crosslinked poly(N-isopropylacrylamide) hydrogels. The results show that repeated thermal cycling leads to the formation of cracks on the surface of the hydrogels. Repeated thermal cycling also results in a decreased degree of swelling in the crosslinked poly(N-isopropylacrylamide) hydrogels at temperatures below the volume phase transition temperature (VPTT).

UI	MeSH Term	Description	Entries
D008422	Materials Testing	The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.	Biocompatibility Testing,Biocompatible Materials Testing,Hemocompatibility Testing,Testing, Biocompatible Materials,Testing, Hemocompatible Materials,Hemocompatibility Testings,Hemocompatible Materials Testing,Materials Testing, Biocompatible,Materials Testing, Hemocompatible,Testing, Biocompatibility,Testing, Hemocompatibility,Testing, Materials,Testings, Biocompatibility
D009682	Magnetic Resonance Spectroscopy	Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).	In Vivo NMR Spectroscopy,MR Spectroscopy,Magnetic Resonance,NMR Spectroscopy,NMR Spectroscopy, In Vivo,Nuclear Magnetic Resonance,Spectroscopy, Magnetic Resonance,Spectroscopy, NMR,Spectroscopy, Nuclear Magnetic Resonance,Magnetic Resonance Spectroscopies,Magnetic Resonance, Nuclear,NMR Spectroscopies,Resonance Spectroscopy, Magnetic,Resonance, Magnetic,Resonance, Nuclear Magnetic,Spectroscopies, NMR,Spectroscopy, MR
D011108	Polymers	Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).	Polymer
D011232	Chemical Precipitation	The formation of a solid in a solution as a result of a chemical reaction or the aggregation of soluble substances into complexes large enough to fall out of solution.	Precipitation, Chemical
D002152	Calorimetry, Differential Scanning	Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.	Differential Thermal Analysis, Calorimetric,Calorimetric Differential Thermal Analysis,Differential Scanning Calorimetry,Scanning Calorimetry, Differential
D002845	Chromatography	Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.	Chromatographies
D003692	Delayed-Action Preparations	Dosage forms of a drug that act over a period of time by controlled-release processes or technology.	Controlled Release Formulation,Controlled-Release Formulation,Controlled-Release Preparation,Delayed-Action Preparation,Depot Preparation,Depot Preparations,Extended Release Formulation,Extended Release Preparation,Prolonged-Action Preparation,Prolonged-Action Preparations,Sustained Release Formulation,Sustained-Release Preparation,Sustained-Release Preparations,Timed-Release Preparation,Timed-Release Preparations,Controlled-Release Formulations,Controlled-Release Preparations,Extended Release Formulations,Extended Release Preparations,Slow Release Formulation,Sustained Release Formulations,Controlled Release Formulations,Controlled Release Preparation,Controlled Release Preparations,Delayed Action Preparation,Delayed Action Preparations,Formulation, Controlled Release,Formulations, Controlled Release,Prolonged Action Preparation,Release Formulation, Controlled,Release Formulations, Controlled,Sustained Release Preparation,Timed Release Preparation,Timed Release Preparations
D004055	Differential Thermal Analysis	Technique by which phase transitions of chemical reactions can be followed by observation of the heat absorbed or liberated.	Analysis, Differential Thermal,Thermal Analysis, Differential,Analyses, Differential Thermal,Differential Thermal Analyses,Thermal Analyses, Differential
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D000180	Acrylic Resins	Polymers of high molecular weight which are derived from acrylic acid, methacrylic acid or other related compounds and are capable of being molded and then hardened to form useful components.	Acrylic Resin,Resin, Acrylic,Resins, Acrylic