ABSTRACT
The work presented here reports the use of long lifetime (>1 µs) BSA Au clusters as a cellular/tissue, time gated, intensity imaging probe. By collecting the emission signal 50 ns post excitation, one can off-gate the intense auto-fluorescence background, thereby greatly enhancing the clarity/specificity in fluorescence imaging.
Subject(s)
Fluorescent Dyes/metabolism , Gold/chemistry , Nanostructures/chemistry , Serum Albumin, Bovine/chemistry , Animals , Cattle , Cell Line, Tumor , Fluorescent Dyes/chemistry , Mice , Microscopy, Fluorescence , Serum Albumin, Bovine/metabolismABSTRACT
Magnetic nanoparticles (NP) were developed for the active brain targeting of water-soluble P-glycoprotein (P-gp) substrate rhodamine 123 (Rh123). The NP matrix of poly(lactide-co-glycolide) (PLGA) and methoxy poly(ethyleneglycol)-poly(lactic acid) (M-PEG-PLA) was prepared by single emulsion solvent evaporation of polymers with oleic acid-coated magnetic nanoparticles (OAMNP) and Rh123. All formulations were characterized in terms of morphology, particle size, magnetic content and Rh123 encapsulation efficiency. The maximum encapsulation efficiency of Rh123 was 45 ± 3% and of OAMNP was 42 ± 4%. The brain targeting and biodistribution study was performed on Sprague Dawley rats (3 groups, n = 6). Rh123 (0.4 mg kg(-1)) was administered in saline form, NP containing Rh123, and NP containing Rh123 in the presence of a magnetic field (0.8 T). The fluorimetric analysis of brain homogenates revealed a significant uptake (p < 0.05) of Rh123 in the magnetically targeted group relative to controls. These results were supported by fluorescence microscopy. This study reveals the ability of magnetically targeted nanoparticles to deliver substances to the brain, the permeation of which would otherwise be inhibited by the P-gp system.
Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Brain/metabolism , Drug Carriers/pharmacokinetics , Fluorescent Dyes/pharmacokinetics , Magnetite Nanoparticles/chemistry , ATP Binding Cassette Transporter, Subfamily B, Member 1/chemistry , Animals , Brain Chemistry , Drug Carriers/chemistry , Drug Delivery Systems , Fluorescent Dyes/chemistry , Histocytochemistry , Lactic Acid/chemistry , Male , Microscopy, Fluorescence , Oleic Acid/chemistry , Polyethylene Glycols/chemistry , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Rats , Rats, Sprague-Dawley , Rhodamine 123/chemistry , Rhodamine 123/pharmacokinetics , Tissue DistributionABSTRACT
This work reports the surface functionalization of polymeric PLGA nanoparticles by non-covalent insertion of a homo-bifunctional chemical crosslinker, bis(sulfosuccinimidyl) suberate (BS3) for targeted cancer therapy. We dissolved BS3 in aqueous solution of PVA during formulation of nanoparticles by a modified solid/oil/water emulsion solvent evaporation method. The non-covalent insertion of BS3 was confirmed by Fourier transform infrared (FTIR) spectroscopy. Curcumin and annexin A2 were used as a model drug and a cell specific target, respectively. Nanoparticles were characterized for particle size, zeta potential and surface morphology. The qualitative assessment of antibody attachment was performed by transmission electron microscopy (TEM) as well as confocal microscopy. The optimized formulation showed antibody attachment of 86%. However, antibody attachment was abolished upon blocking the functional groups of BS3. The availability of functional antibodies was evaluated by the presence of a light chain fraction after gel electrophoresis. We further evaluated the in vitro release kinetics of curcumin from antibody coated and uncoated nanoparticles. The release of curcumin is enhanced upon antibody attachment and followed an anomalous release pattern. We also observed that the cellular uptake of nanoparticles was significantly higher in annexin A2 positive cells than in negative cells. Therefore, these results demonstrate the potential use of this method for functionalization as well as to deliver chemotherapeutic agents for treating cancer.
Subject(s)
Cross-Linking Reagents/chemistry , Drug Delivery Systems/methods , Lactic Acid/chemistry , Nanoparticles/chemistry , Neoplasms/therapy , Polyglycolic Acid/chemistry , Succinimides/chemistry , Antibodies/immunology , Cell Line, Tumor , Curcumin/pharmacology , Humans , Kinetics , Microscopy, Confocal , Nanoparticles/ultrastructure , Particle Size , Polylactic Acid-Polyglycolic Acid Copolymer , Spectroscopy, Fourier Transform Infrared , Surface Properties/drug effectsABSTRACT
This work reports the targeting of the near infrared (NIR) dye indocyanine green (ICG) to the brain using composite nanoparticles. Thermal decomposition of iron pentacarbonyl was used to synthesize monodisperse oleic acid coated magnetic nanoparticles (OAMNP). Synthesized OAMNP and ICG were encapsulated in a poly (lactide-co-glycolide) matrix using an emulsion evaporation method. Different batches containing OAMNP:PLGA ratios (1:4, 1:2 and 3:4) were prepared with ICG (group B-1, 2, 3) and without ICG (group A-1, 2, 3) loading. All the formulations were characterized in terms of morphology, particle size, zeta potential, magnetic content, ICG encapsulation efficiency and the spectral properties of ICG. The optimized formulation showed an encapsulation efficiency of 56 +/- 4.6% for ICG and 57 +/- 1.37% for OAMNP. The biodistribution and brain targeting study involved three groups of six animals, each with 0.4 mg kg(-1) equivalent of ICG, given as neat ICG solution, composite nanoparticles without the aid of a magnetic field, and composite nanoparticles under the influence of a magnetic field (8000 G) to groups 1, 2 and 3 respectively. The tissue analysis and microscopy images revealed a significantly higher brain concentration of ICG (p < 0.05) for group 3 than the two control groups. These results are encouraging for the brain delivery of hydrophilic dyes/drugs using this method for biomedical applications.
