Near-Infrared Dye-Loaded Plga Nanoparticles Prepared by Spray Drying for Photoacoustic Applications

• Published in: International journal of artificial organs 2011-02, Vol.34 (2), p.249-254
• Main Authors: Kohl, Yvonne, Kaiser, Christian, Bost, Wolfgang, Stracke, Frank, Thielecke, Hagen, Wischke, Christian, Lendlein, Andreas, Kratz, Karl, Lemor, Robert
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cell Proliferation - drug effects; Cell Survival - drug effects; Cercopithecus aethiops; Coloring Agents - chemistry; Coloring Agents - toxicity; Contrast Media - chemistry; Contrast Media - toxicity; Contrast media. Radiopharmaceuticals; Energy Metabolism - drug effects; Hep G2 Cells; Humans; Indocyanine Green - chemistry; Indocyanine Green - toxicity; Medical sciences; Nanoparticles; Particle Size; Pharmacology. Drug treatments; Polyglactin 910 - chemistry; Polyglactin 910 - toxicity; Spectroscopy, Near-Infrared; Surface Properties; Vero Cells
• ISSN: 0391-3988; 1724-6040
• DOI: 10.5301/IJAO.2011.6405

Introduction Nanoparticulate contrast agents are of great interest for diagnostic applications with high resolution in medicine. Here we present polymer-based degradable nanoparticles exhibiting a near infrared (NIR) absorption suitable for photoacoustic imaging. Methods The nanoparticles were prepared by incorporation of indocyanine green (ICG) as NIR dye in poly[(rac-lactide)-co-glycolide] (PLGA) via an optimized spray drying process. By application of a multi-step centrifugation protocol, two different size fractions were achieved. The biocompatibitilty of the nanoparticles was tested in 2D cell cultures (human hepatocarcinoma cells and monkey kidney cells) using WST-1, BrdU and LDH assay. Results Spherical particles were obtained with a good yield (>81%), showing a high NIR-dye encapsulation efficiency (>98%). By multi-step centrifugation, two different size fractions with a mean diameter of 640 nm and 390 nm were obtained. Cytotoxicity studies of the synthesized ICG-loaded PLGA particles were performed. No cytotoxic effect on metabolic activity, proliferation, or membrane integrity was observed. Conclusion The high optical absorption at the relevant NIR-wavelength around 800 nm in combination with absence of cytotoxicity qualifies the ICG-loaded PLGA particles as promising candidates for degradable photoacoustic contrast agents.