Abstract
New thermo-responsive, pH-responsive, and biodegradable nanoparticles comprised of poly(d,l-lactide)-graft-poly(N-isopropyl acrylamide-co-methacrylic acid) (PLA-g-P(NIPAm-co-MAA)) were developed by grafting biodegradable poly(d,l-lactide) onto N-isopropyl acrylamide and methacrylic acid. A core-shell type nano-structure was formed with a hydrophilic outer shell and a hydrophobic inner core, which exhibited a phase transition temperature above 37°C suitable for biomedical application. Upon heating above the phase transition temperature, PLA-g-P(NIPAm-co-MAA) nanoparticle showed a polarity increase of pyrene in either buffer solution or intra-hepato-carcinoma cells as determined by fluorescence measurement, indicating that the structure of nanoparticles caused leakages from outer shell copolymers aggregation and collapsed. The drug loading level of 5-fluorouracil (5-FU) encapsulated in the PLA-g-P(NIPAm-co-MAA) nanoparticles can be as high as 20%. The release of 5-FU from nanoparticles was strongly controlled by the pH in the aqueous solution. Based on these results, PLA-g-P(NIPAm-co-MAA) nanoparticles can be used as a drug carrier for intracellular delivery of anti-cancer drug.
Original language | English |
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Pages (from-to) | 477-488 |
Number of pages | 12 |
Journal | Journal of Controlled Release |
Volume | 104 |
Issue number | 3 |
DOIs | |
State | Published - 2 Jun 2005 |
Keywords
- 5-Fluorouracil
- Graft copolymer
- Intelligent nanoparticle
- Intracellular drug delivery
- Structural changes