ABSTRACT
AIM: T lymphocytes are used as cellular therapeutics in many disease entities including cancer. We investigated the uptake and retention of nanoparticles (NPs) by these nonphagocytic cells. MATERIALS & METHODS: Uptake, release and toxicity of various polymeric NP preparations were analyzed by flow cytometry, confocal laser scanning microscopy and transmission electron microscopy. T-cell effector functions were measured using IFN-γ-ELISPOT and (51)Chromium-release assays. RESULTS: Amino-functionalized NPs were efficiently ingested by antigen-specific T cells without adversely influencing effector functions. NPs were stored in membrane-surrounded vesicles, with major proportions released extracellularly during 24 h. CONCLUSION: Amino-functionalized polymeric NPs are efficiently taken up by human T cells and could be used to design nanocarriers for direct access and manipulation of antigen-specific T cells in vivo.
Subject(s)
CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Drug Carriers/metabolism , Nanoparticles/metabolism , Polymers/metabolism , Animals , CD4-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/drug effects , Cell Line , Drug Carriers/chemistry , Drug Delivery Systems , Drug Liberation , Endocytosis , Humans , Mice, Inbred C57BL , Microscopy, Confocal , Microscopy, Electron, Transmission , Nanoparticles/chemistry , Nanoparticles/ultrastructure , Polymers/chemistryABSTRACT
Various contrast agents (Magnevist, Gadovist and Multihance) loaded into polymeric nanocapsules were synthesized by the inverse miniemulsion technique. The relaxivity of the resultant contrast agents was assessed at 1.5 T magnetic field strength. The ionic relaxivity of the contrast agents could at least be maintained after their encapsulation in different polymer capsules. The chemical composition of the nanocapsules was characterized by Fourier transform infrared spectroscopy. The distribution of the contrast agent in the nanocapsules could be identified by energy filtered transmission electron microscopy and energy dispersive X-ray spectroscopy. The results indicate entrapment of the gadolinium complex into the inner shell of the polymeric nanocapsules. The payload of contrast agent per nanocapsule resulted in some 2.5 x 10(6) Gd(3+) complexes yielding a particle-based relaxivity of 10.75 x 10(6) mM(-1) s(-1). Maintained or even slightly increased ionic relaxivity of the different contrast agents after encapsulation in combination with high payloads and the possibility of functionalization of the capsules' surface facilitate the application of the nanocapsules as promising targeted contrast agents for MRI.
Subject(s)
Contrast Media/chemistry , Magnetic Resonance Imaging/methods , Nanocapsules , Chemistry Techniques, Analytical , Gadolinium , Materials Testing , Nanocapsules/chemistry , Polymers/chemistryABSTRACT
The functionalization of well-defined PU nanocapsules with an aqueous core prepared by performing a polyaddition at the interface of inverse (water-in-oil) miniemulsion droplets is demonstrated. The miniemulsion technique involving the nanoreactor concept allows one to obtain an encapsulation efficiency as high as 90% within the nanocapsules. A pH independent fluorescent dye is used as a model system for the aqueous core. By varying the molar ratio of the diol to the diisocyanate at a fixed surfactant concentration, the shell thickness of the nanocapsules can be finely tuned. The carboxy- and amino-functionalized surface of the nanocapsules can be tailored by an in-situ carboxymethylation reaction and by physical adsorption of a cationic polyelectrolyte, i.e. PAEMA or PEI. The increased uptake of amino-functionalized fluorescent nanocapsules by HeLa cells clearly demonstrates the potential of the functionalized nanocapsules to be successfully exploited as biocarriers.
Subject(s)
Drug Carriers/chemistry , Emulsions/chemistry , Nanocapsules/chemistry , Polyurethanes/chemistry , Adsorption , Electric Conductivity , Fluorescence , HeLa Cells , Humans , Microscopy, Confocal , Nanocapsules/ultrastructure , Spectroscopy, Fourier Transform Infrared , Surface PropertiesABSTRACT
The modified nanoprecipitation of polymers onto stable nanodroplets has been successfully applied to prepare well-defined nanocapsules whose core is composing of an antiseptic agent, i.e., chlorhexidine digluconate aqueous solution. The stable nanodroplets were obtained by inverse miniemulsions with an aqueous antiseptic solution dispersed in an organic medium of solvent/nonsolvent mixture containing an oil-soluble surfactant and the polymer for the shell formation. The change of gradient of the solvent/nonsolvent mixture of dichloromethane/cyclohexane, obtained by heating at 50 degrees C, led to the precipitation of the polymer in the organic continuous phase and deposition onto the large interface of the aqueous miniemulsion droplets. The monodisperse polymer nanocapsules with the size range of 240-80 nm were achieved as a function of the amount of surfactant. Using various polymer contents, molecular weights and types, an encapsulation efficiency of 20-100% was obtained as detected by proton-nuclear magnetic resonance spectroscopy ((1)H NMR) measurements. The nanocapsules could be easily transferred into water as continuous phase resulting in aqueous dispersions with nanocapsules containing an aqueous core with the antiseptic agent. The encapsulated amount of the antiseptic agent was evaluated to indicate the durability of the nanocapsule's wall. In addition, the use of different types of polymers having glass transition temperatures (T(g)) ranging from 10 to 100 degrees C in this process has been also successful.
