Thermoresponsive Nanostructures by Self-Assembly of a Poly(N-isopropylacrylamide)-Lipid Conjugate

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• 作者：Daniel N. T. Hay ; Paul G. Rickert ; Sö ; nke Seifert ; and Millicent A. Firestone
• 刊名：Journal of the American Chemical Society
• 出版年：2004
• 出版时间：March 3, 2004
• 年：2004
• 卷：126
• 期：8
• 页码：2290 - 2291
• 全文大小：36K
• 年卷期：v.126,no.8(March 3, 2004)
• ISSN：1520-5126

文摘

The synthesis and purification of a poly(N-isopropylacrylamide)-lipid conjugate and its use in the preparation of a thermoresponsive lipid mesophase is described. Specifically, poly(N-isopropylacrylamide) with a single carboxyl group at one end was activated with dicyclohexylcarbodiimide/N-hydroxysuccinimide to form an active ester. This N-hydroxysuccinimide ester was then used to form a dimyristoyl-sn-glycero-3-phosphoethanolamine conjugate with poly(N-isopropylacrylamide) via an amide bond, rendering the conjugate amphiphilic. Quaternary phases comprising the conjugate, a phosopholipid, dimyristoylphosphatidylcholine, and a cosurfactant, N,N-dimethyldodecylamine-N-oxide, dispersed in water were found to self-assemble at room temperature to form liquid crystalline gels, adopting an expanded lamellar structure. A modest increase in temperature triggered the reversible conversion of the aggregate to a collapsed lamellar structure, while a modest reduction in temperature resulted in its conversion to a nonlamellar phase. The phases were characterized by polarized optical microscopy and small-angle X-ray scattering (SAXS).