title: Tumor accumulation of NIR fluorescent PEG-PLA nanoparticles: impact of particle size and human xenograft tumor model.
abstract: Cancer therapies are often terminated due to serious side effects of the drugs. The cause is the nonspecific distribution of chemotherapeutic agents to both cancerous and normal cells. Therefore, drug carriers which deliver their toxic cargo specific to cancer cells are needed. Size is one key parameter for the nanoparticle accumulation in tumor tissues. In the present study the influence of the size of biodegradable nanoparticles was investigated in detail, combining in vivo and ex vivo analysis with comprehensive particle size characterizations. Polyethylene glycol-polyesters poly(lactide) block polymers were synthesized and used for the production of three defined, stable, and nontoxic near-infrared (NIR) dye-loaded nanoparticle batches. Size analysis based on asymmetrical field flow field fractionation coupled with multiangle laser light scattering and photon correlation spectroscopy (PCS) revealed narrow size distribution and permitted accurate size evaluations. Furthermore, this study demonstrates the constraints of particle size data only obtained by PCS. By the multispectral analysis of the Maestro in vivo imaging system the in vivo fate of the nanoparticles next to their accumulation in special red fluorescent DsRed2 expressing HT29 xenografts could be followed. This simultaneous imaging in addition to confocal microscopy studies revealed information about the accumulation characteristics of nanoparticles inside the tumor tissues. This knowledge was further combined with extended size-dependent fluorescence imaging studies at two different xenograft tumor types, the HT29 (colorectal carcinoma) and the A2780 (ovarian carcinoma) cell lines. The combination of two different size measurement methods allowed the characterization of the dependence of nanoparticle accumulation in the tumor on even rather small differences in the nanoparticle size. While two nanoparticle batches (111 and 141 nm in diameter) accumulated efficiently in the human xenograft tumor tissue, the slightly bigger nanoparticles (diameter 166 nm) were rapidly eliminated by the liver.
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schädlich
authors.forename: Henrike
authors.initials: H
authors.lastname: Caysa
authors.forename: Thomas
authors.initials: T
authors.lastname: Mueller
authors.forename: Frederike
authors.initials: F
authors.lastname: Tenambergen
authors.forename: Cornelia
authors.initials: C
authors.lastname: Rose
authors.forename: Achim
authors.initials: A
authors.lastname: Göpferich
authors.forename: Judith
authors.initials: J
authors.lastname: Kuntsche
authors.forename: Karsten
authors.initials: K
authors.lastname: Mäder
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism* / Q000493:pharmacokinetics; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D031521:Fractionation, Field Flow; D019073:HT29 Cells; D006801:Humans; D007259:Infrared Rays; D007773:Lactates / Q000737:chemistry*; D007834:Lasers; D008164:Luminescent Proteins / Q000378:metabolism; D008297:Male; D051379:Mice; D018613:Microscopy, Confocal; D053758:Nanoparticles / Q000737:chemistry*; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D012542:Scattering, Radiation; D013057:Spectrum Analysis
chemical_list: D004337:Drug Carriers; D005456:Fluorescent Dyes; D007773:Lactates; D008164:Luminescent Proteins; C413663:fluorescent protein 583; C088513:poly(lactic acid-ethylene glycol); D011092:Polyethylene Glycols