Polymeric micelle nanoparticles for photodynamic treatment of head and neck cancer cells.
OBJECTIVE
To encapsulate 5,10,15,20-tetrakis(meso-hydroxyphenyl)porphyrin (mTHPP), a photosensitizer, into polymeric micelles; characterize the micelles; and test in vitro photodynamic therapy efficacy against human head and neck cancer cells.


METHODS
A nanoparticle design, fabrication, and in vitro testing study.


METHODS
Polymer chemistry laboratory.


METHODS
Micelles encapsulating mTHPP were produced, and micellar size was measured. Ultraviolet visible spectra and fluorescence spectroscopy were used to characterize the mTHPP-loaded micelles. In vitro cell culture using HSC-3 and HN-5 cancer cells was performed to test the photodynamic therapy efficacy of the micelles using confocal microscopy and method of transcriptional and translational (MTT) assay.


RESULTS
mTHPP was encapsulated with high loading efficiency (> 85%) and density (up to 17%) into micelles. Micelle size was 30.6 +/- 3.3 nm by transmission electron microscopy and 30.8 +/- 0.6 nm by dynamic light scattering. The absorption maximum for each sample was 418 nm, and fluorescent spectroscopy revealed quenching with maximal fluorescence at five percent loading. Significant cytotoxicity was observed with confocal microscopy when HSC-3 cells were treated with 10 percent mTHPP micelles, with 100 percent cytotoxicity within the zone of laser light exposure at 420 nm. Phototoxicity and dark toxicity against HSC-3 and HN-5 cells measured using the MTT assay with five and 10 percent loaded mTHPP micelles demonstrated greater than 90 percent cytotoxicity with photodynamic therapy and less than 10 percent dark toxicity at a micelle concentration of 25 microg/mL for both cell lines.


CONCLUSIONS
Micelles were able to encapsulate and solubilize mTHPP at high loading densities with uniform size distribution. These micelles exhibit fluorescence and photodynamic therapy mediated cytotoxicity against head and neck cancer cells in vitro.
Cohen
Evan M
EM
Department of Pharmacology, Simmons Comprehensive Cancer Center, Dallas, TX, USA.
Ding
Huiying
H
Kessinger
Chase W
CW
Khemtong
Chalermchai
C
Gao
Jinming
J
Sumer
Baran D
BD
D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000473:pathology; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D004337:Drug Carriers; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D008823:Micelles; D053758:Nanoparticles; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D011092:Polyethylene Glycols; D011166:Porphyrins / Q000008:administration & dosage*
D004337:Drug Carriers; D008823:Micelles; D017319:Photosensitizing Agents; D011166:Porphyrins; C542623:monomethoxypolyethyleneglycol-polylactide block copolymer; C437342:tetra(3-hydroxyphenyl)porphine; D011092:Polyethylene Glycols