title: Bionanoprobes to study particle-cell interactions.
abstract: A variety of research reports have provided evidence that the interplay between nanoparticles and biological systems is strongly dependent on the composition as well as on the size of the particles. However, irrespective of that a fine tuning of the interaction characteristics can be attained by functionalisation of the particle surface. In order to be able to monitor such interactions, an analytically accessible model system for potentially target-specific therapeutically relevant nanoparticles (NP) was generated by encapsulation of the highly hydrophobic fluorophore BODIPY 493/503 into poly(D,L-lactide-co-glycolide) (PLGA) nanodroplets. Analyses of the mean particle size and zeta potential revealed that plain and human serum albumin (HSA) conjugated NP can be stored without agglomeration for at least 28 days at 4 degrees C as well as -80 degrees C. Although transfer of the particles into commonly used buffers and cell culture medium did not affect the system's stability, protein-containing dispersants should not be used for experiments demanding high sensitivity as distinct quenching effects were observed. Concerning liberation of the fluorescent marker, no release occurred when incubating the suspension for 7 days at 4 degrees C, while an onset of release was expectedly detected after 3 h at 37 degrees C. These experimental limitations were taken into account for the particle-cell interaction studies which, as a consequence of the more hydrophilic particle surface, showed an enhanced adhesion of HSA-conjugated colloids to Caco-2 cells by means of flow cytometry and fluorescence microscopy.
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Fillafer
authors.forename: Daniela S
authors.initials: DS
authors.lastname: Friedl
authors.forename: Adina K
authors.initials: AK
authors.lastname: Ilyes
authors.forename: Michael
authors.initials: M
authors.lastname: Wirth
authors.forename: Franz
authors.initials: F
authors.lastname: Gabor
mesh_terms: D001896:Boron Compounds / Q000032:analysis* / Q000737:chemistry; D018938:Caco-2 Cells; D002450:Cell Communication; D005434:Flow Cytometry; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012709:Serum Albumin / Q000138:chemical synthesis / Q000737:chemistry; D013696:Temperature
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D012709:Serum Albumin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid