title: Optoacoustic imaging enabled biodistribution study of cationic polymeric biodegradable nanoparticles.
abstract: Nanosized contrast agents for molecular imaging have attracted widespread interest for diagnostic applications with high resolution in medicine. However, many solid nanoparticles exhibit a great potential to induce toxicity, hindering their use for clinical applications. On the other hand, near-infrared (NIR) dyes have also been used for extensive biological applications, but show some limitations due to their poor aqueous stability, tendency to aggregation and rapid elimination from the body. An alternative proposed in this work to overcome these limitations is the use of NIR dye-loaded nanoparticles. Here we introduce nanoparticles constructed with poly(D,L-lactide-co-glycolic acid) (PLGA), a biodegradable and biocompatible polymer widely used for biomedical applications, attached to the polycation polyethyleneimine (PEI) to obtain positively charged nanoparticles. The in vivo biodistribution of the cationic PEI-PLGA nanoparticles was investigated after administration through three different routes (intravenous, intraperitoneal and subcutaneous) using multispectral optoacoustic tomography (MSOT). The prepared nanoparticles exhibited good colloidal stability and adequate optical properties for optoacoustic imaging. The in vivo biodistribution assays indicated a strong accumulation of the particles in the liver and spleen, and retention in these organs for at least 24 h. Therefore, these nanoparticles could find promising applications in MSOT due to a sharp and characteristic optoacoustic spectrum and high optoacoustic signal generation, and become a promising building block for theranostic strategies.
authors.affiliation: NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.|Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
authors.forename: Susana P
authors.initials: SP
authors.lastname: Egusquiaguirre
authors.affiliation: Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Neuherberg, Munich, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Beziere
authors.affiliation: NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.|Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
authors.forename: José Luís
authors.initials: JL
authors.lastname: Pedraz
authors.affiliation: NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.|Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Hernández
authors.affiliation: Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Neuherberg, Munich, Germany.
authors.forename: Vasilis
authors.initials: V
authors.lastname: Ntziachristos
authors.affiliation: NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.|Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
authors.forename: Manuela
authors.initials: M
authors.lastname: Igartua
mesh_terms: D000818:Animals; D063566:Biodegradable Plastics / Q000032:analysis*; D045744:Cell Line, Tumor; D003287:Contrast Media / Q000493:pharmacokinetics*; D019344:Lactic Acid / Q000737:chemistry; D051379:Mice; D057054:Molecular Imaging / Q000379:methods*; D053758:Nanoparticles / Q000032:analysis*; D019047:Phantoms, Imaging; D061088:Photoacoustic Techniques / Q000379:methods*; D011094:Polyethyleneimine / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000032:analysis* / Q000737:chemistry
chemical_list: D063566:Biodegradable Plastics; D003287:Contrast Media; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011094:Polyethyleneimine
keywords: MSOT; biodistribution; cationic nanoparticles; imaging; nanoparticles; optoacoustic