Poly(N-isopropylacrylamide)-based semi-interpenetrating polymer networks for tissue engineering applications. Effects of linear poly(acrylic acid) chains on rheology.
Semi-interpenetrating polymer networks (semi-IPNs), comprised of poly(N-isopropylacrylamide-co-acrylic acid) (p(NIPAAm-co-AAc)) hydrogels and linear p(AAc) chains, were synthesized, and the effects of the p(AAc) chains on semi-IPN rheology were examined. Oscillatory shear rheometry studies were performed and the rheological data were analyzed as a function of temperature, frequency, and p(AAc) chain amount (weight average molecular weight (Mw) 4.5 x 10(5) g/mol). At 22 degrees C, the semi-IPNs, as well as control p(NIPAAm-co-AAc) hydrogels, demonstrated rheological data that were representative of soft, loosely cross-linked solids. Furthermore, only the highest p(AAc) chain amount tested affected the rigidity of the p(NIPAAm-co-AAc)-based semi-IPNs, as compared to the p(NIPAAm-co-AAc) hydrogels. At 37 degrees C, the complex shear moduli (G*) demonstrated by the p(NIPAAm-co-AAc)-based semi-IPNs were significantly greater than G* exhibited by the p(NIPAAm-co-AAc) hydrogels, and the semi-IPN G* values significantly increased with increasing p(AAc) chain amount. These results can be used to develop p(NIPAAm)-based semi-IPNs with tailored mechanical properties that may function as scaffolds in tissue engineering initiatives.
Stile
Ranee A
RA
Department of Biomedical Engineering, Robert R. McCormick School of Engineering and Applied Sciences, Northwestern University, Evanston, IL 60208, USA.
Chung
Eugene
E
Burghardt
Wesley R
WR
Healy
Kevin E
KE
D000179:Acrylates; D000180:Acrylic Resins / Q000737:chemistry*; D000704:Analysis of Variance; D003094:Collagen / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008956:Models, Chemical; D009991:Oscillometry; D011108:Polymers / Q000737:chemistry*; D012212:Rheology / Q000379:methods; D013696:Temperature; D023822:Tissue Engineering / Q000379:methods*
D000179:Acrylates; D000180:Acrylic Resins; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C006903:carbopol 940; D003094:Collagen; C036658:acrylic acid