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Thermoresponsive nanocomposite hydrogels with cell-releasing behavior

Paper ID Volume ID Publish Year Pages File Format Full-Text
9760 645 2008 10 PDF Available
Title
Thermoresponsive nanocomposite hydrogels with cell-releasing behavior
Abstract

Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels become more hydrophobic when they reversibly switch from a water-swollen to a deswollen state above the volume phase transition temperature (VPTT, ∼33 °C) which has been used to modulate cell adhesion. In the current work, we prepared novel thermoresponsive nanocomposite hydrogels comprised of a PNIPAAm hydrogel matrix and polysiloxane colloidal nanoparticles (∼220 nm average diameter) via in situ photopolymerization of aqueous solutions of NIPAAm monomer, N,N′-methylenebisacrylamide (BIS, crosslinker), photoinitiator and polysiloxane nanoparticles (0.5–2.0 wt% based on solution weight) at ∼7 °C. The VPTT of the nanocomposite hydrogels is not altered versus the pure PNIPAAm hydrogel. Dynamic mechanical analysis and tensile tests revealed that higher nanoparticle content generally produced improved hydrogel mechanical properties. Surfaces of nanocomposite hydrogels became increasingly more hydrophobic at all temperatures between 10 and 40 °C as the amount of hydrophobic polysiloxane nanoparticles was increased. When cooled from 37 to 25 °C, mouse smooth muscle precursor cells (10T1/2) were effectively detached from nanocomposite hydrogel surfaces. The utility of photopatterning to create surface micropillars comprised of nanocomposite hydrogels was demonstrated.

Keywords
Hydrogel; Thermally responsive material; Siloxane; Nanoparticles; Cell adhesion; Photopolymerization
First Page Preview
Thermoresponsive nanocomposite hydrogels with cell-releasing behavior
Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 29, Issue 22, August 2008, Pages 3175–3184
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering