Utilization of micelles formed from poly(ethylene glycol)-block-poly(epsilon-caprolactone) block copolymers as nanocarriers to enable hydrophobic red two-photon absorbing emitters for cells imaging.
A hydrophobic two-photon absorbing (2PA) red emitter (R) was successfully incorporated into micelles formed from two block copolymers, poly(epsilon-caprolactone)-block-poly(ethylene glycol)s, for imaging and toxicity studies. In micelles, the chromophore R exhibits a 2PA cross-section of 400 GM (1 GM = 1 x 10(-50) cm(4) s photon(-1) molecule(-1)) at 820 nm, which is among the highest values reported for red 2PA emitters. The micelles with a cationic amino moiety-containing poly(ethylene glycol) corona showed an enhancement of cell internalization and delivered the dye into the cytoplasmic regions of the mouse macrophage RAW 264.7 cells. In comparison, the dye in micelles with neutral poly(ethylene glycol) as corona could not be delivered into the cells. Cytotoxicity of the micelle-R constructs was studied using a 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. More than 90% of the cells were viable after they were stained with the dye-containing micelles at different concentrations (dye concentrations of 2-6 muM and polymer concentrations of 0.05-0.15 mg/mL) for 16 h. This is the first reported application of a hydrophobic 2,1,3-benzothiadiazole-containing 2PA red emitter delivered into the cytoplasm of cells for bioimaging and toxicity assessment.
Tian
Yanqing
Y
Department of Materials Science and Engineering, University of Washington, Box 352120, Seattle, Washington 98195-2120, USA.
Wu
Wen-Chung
WC
Chen
Ching-Yi
CY
Jang
Sei-Hum
SH
Zhang
Meng
M
Strovas
Tim
T
Anderson
Judy
J
Cookson
Brad
B
Li
Yongzhong
Y
Meldrum
Deirdre
D
Chen
Wen-Chang
WC
Jen
Alex K-Y
AK
D000042:Absorption / Q000187:drug effects; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002850:Chromatography, Gel; D004337:Drug Carriers / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D007783:Lactones / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008823:Micelles; D018613:Microscopy, Confocal; D049329:Nanostructures / Q000737:chemistry*; D017785:Photons; D011092:Polyethylene Glycols / Q000494:pharmacology*; D012542:Scattering, Radiation; D012997:Solvents; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
D004337:Drug Carriers; D007783:Lactones; D008823:Micelles; D012997:Solvents; C521904:poly(ethylene glycol)-block-poly(epsilon-caprolactone); D011092:Polyethylene Glycols