OKANO Teruo    Department   Research Institutes and Facilities, Research Institutes and Facilities    Position
Article types	Original article
Language	English
Peer review	Peer reviewed
Title	Poly (N-isopropylacrylamide)-PLA and PLA blend nanoparticles for temperature-controllable drug release and intracellular uptake.
Journal	Formal name：Colloids and surfaces. B, Biointerfaces Abbreviation：Colloids Surf B Biointerfaces ISSN code：(1873-4367)0927-7765(Linking)
Domestic / Foregin	Foregin
Publisher	Elsevier
Volume, Issue, Page	99,pp.67-73
Author and coauthor	Ayano Eri†, Karaki Miyuki, Ishihara Tsutomu, Kanazawa Hideko*, Okano Teruo
Publication date	2012/11
Summary	We designed a temperature-responsive and biodegradable novel drug-delivery carrier. A block copolymer, poly (N-isopropylacrylamide-dl-lactide) (PNIPAAm-PLA), was synthesized by the ring-opening polymerization of dl-lactide, and used as a carrier for a drug-delivery system. In this study, temperature-responsive nanoparticles (NPs) encapsulating betamethasone disodium 21-phosphate (BP) were prepared from a blend of PLA homopolymer and block copolymers by an oil-in-water solvent-diffusion method in the presence of zinc ion (PLA/PNIPAAm-PLA (NPs)). The resulting NP size was around 140 nm. The drug release from temperature-responsive NP could be controllable by changing the temperature. Moreover, a murine macrophage-like cell line, RAW 264.7 cells, was used to measure and image the cell uptake of fluorescent PLA/PNIPAAm-PLA NPs at 30 °C and 37 °C on the boundary of LCST (34 °C). Below the LCST, cellular uptake was not observed, but contrary to cellular uptake it was clearly observed above the LCST. Moreover, we found this effect to be useful for controlling the stealthiness by changing the temperature. Present temperature-responsive NPs have successfully exhibited thermo-responsive drug release and intracellular uptake while possessing a biodegradable character.
DOI	10.1016/j.colsurfb.2011.10.003
PMID	22088756