Encapsulation Of Fluorescent Dye Research Articles

Encapsulation of Nanomaterials Inside Microtubules by Using a Tau-Derived Peptide.

Microtubules (MTs) are tubular cytoskeletons, which are used for the various applications such as active matters and therapeutic targets. Although modification of the exterior surface of MTs is frequently used for functionalization of MTs, there was no approach to introduce molecules inside MTs. We previously developed a unique peptide binding to the inner surface of MT, which is derived from a MT-associated protein, Tau. The Tau-derived peptide (TP) can be used to introduce various nanomaterials inside MTs. Here we describe the TP-based encapsulation of fluorescent dye, gold nanoparticle, green fluorescent protein, and magnetic CoPt nanoparticles inside MTs.

Dual thermo/oxidation-responsive block copolymers with self-assembly behaviour and synergistic release

The synthesis of novel amphiphilic poly(propylene sulfide) (PPS) and poly(N-isopropylacrylamide) (PNIPAm) block copolymers is reported as a strategy to respond stimuli in inflammatory tissues. In addition to the formation of defined PPS-block-PNIPAm assemblies, the encapsulation of fluorescent dyes and the selective response to the heat and oxidants are studied. The synthesis of the dual responsive PPS-b-PNIPAm is carried out by combining a living anionic ring-opening and an atom transfer radical polymerization (ATRP) process. The resulting copolymers are self-assembled in water to form aggregated structures, which are characterized by dynamic light scattering (DLS) and scanning electronic microscopy (SEM). DLS measurements show that heat and oxidants cause a significant change to the hydrodynamic diameter of the particles. Fluorescent spectroscopy data confirms the liberation of the encapsulated dye, which indicates the decomposition of the particles and validates the concept of stimuli-triggered payload release. Finally, cytotoxicity assays confirm that the PPS-b-PNIPAm copolymer is biocompatible with A549 lung cancer cells.

Polysaccharide gel nanoparticles modified by the Layer-by-Layer technique for biomedical applications

Polysaccharide hydrogels have gained in recent years a considerable attention as one of the most promising materials for biomedical applications. Since they are of natural origin, with high biocompatibility and biodegradability, they are desirable materials in design of novel drug delivery devices. We prepared and characterized polysaccharide, alginate or pectin gel nanoparticles. They were prepared by the reverse microemulsions and physical crosslinking method by calcium (alginate) and zinc (pectin) ions. The average size of synthesized nanoparticles was ∼100nm and the batch concentration was 1010 particles/ml. Morphology of obtained gels nanoparticles were visualized by Cryo-Scanning Electron Microscopy. Then, surface of nanogels was modified by the Layer-by-Layer (LbL) technique using natural and synthetic polyelectrolytes. Encapsulation of fluorescent dyes (Rhodamine b and 5-aminofluorescein) in nanogels networks was performed. Cytotoxicity of non-modified and LbL modified nanoparticles was evaluated by the cellular viability quantification and cell death assessments using MTT and LDH biochemical tests, respectively.

Fluorescence and conductivity studies on wool

An optimized synthetic method for the production of fluorescent conductive wool using pyrene, rhodamine B and fluorescein is reported. The application of fluorescent conductive polymers to wool was studied using solution and mist polymerization techniques. The effects of incorporating fluorescent dopants into the polymerization solution as well as the encapsulation of fluorescent dyes in a polypyrrole (PPy) micelle were also investigated. It was determined on the basis of both conductivity and fluorescence measurements that the encapsulation of dyes in PPy onto the surface of textiles gave the best results.

Polypyrrole Containers Grown on Oil Microdroplets: Encapsulation of Fluorescent Dyes

Polypyrrole microcapsules were synthesized by the chemical deposition of the polymer onto mineral oil droplets adsorbed onto glass or quartz substrates. The droplets act as a kind of a template that directs the polymer growth into the form of three-dimensional containers. The polymer is deposited on both the surface of oil droplets and the glass or quartz substrate entrapping the oil content. The dissolution of chemical species in oil prior to polymer deposition permits the encapsulation of these species within the cavities of the containers. This phenomenon was demonstrated through the entrapment of the fluorescent dyes, pyrene and perylene, within the polymeric capsules. It was shown that the entrapped molecules can be released from the capsules by controlling the hydration of the polymer, which in turn changes the permeability of the oil content through the polypyrrole shells. The polymer growth and encapsulation phenomena were investigated with a range of complementary physicochemical techniques, including microscopic (AFM, SEM, and confocal microscopy) and spectroscopic (steady-state fluorescence and UV-vis absorption) methods. In particular, the use of optical methods was possible due to the deposition of the capsules on transparent substrates (glass, quartz). As a consequence, the optical information on the interior of the capsules was accessible, for example, dye concentration and local polarity.