Ultrasound-mediated drug delivery using liposomes modified with a thermosensitive polymer.
Ultrasound-mediated drug delivery was established using liposomes that were modified with the thermosensitive polymer (TSP) poly(NIPMAM-co-NIPAM), which sensitized the liposomes to high temperatures. TSP-modified liposomes (TSP liposomes) released encapsulated calcein under 1 MHz ultrasound irradiation at 0.5 W/cm(2) for 120 s as well as the case under incubation at 42 °C for 15 min. In addition, uptake of the drug released from TSP liposomes by cancer cells was enhanced by ultrasound irradiation. In a cell injury assay using doxorubicin (DOX)-loaded TSP liposomes and ultrasound irradiation, cell viability of HepG2 cells at 6 h after ultrasound irradiation (1 MHz, 0.5 W/cm(2) for 30 s) with DOX-loaded TSP liposomes (TSP/lipid ratio=1) was 60%, which was significantly lower than that of the control conditions such as DOX-loaded TSP liposomes alone and DOX-loaded intact liposomes under ultrasound irradiation.
Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa 920-1192, Japan.
Kazuaki
K
Ninomiya
Shinya
S
Kawabata
Hiroyuki
H
Tashita
Nobuaki
N
Shimizu
D000180:Acrylic Resins / Q000737:chemistry*; D001692:Biological Transport; D016503:Drug Delivery Systems / Q000379:methods*; D056945:Hep G2 Cells; D006801:Humans; D008081:Liposomes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D014465:Ultrasonics
D000180:Acrylic Resins; D008081:Liposomes; D011108:Polymers; C587677:poly(N-isopropylmethacrylamide-co-N-isopropylacrylamide)
Cavitation; Drug delivery; Temperature-sensitive liposomes; Thermosensitive polymer; Ultrasound