Chariya Kaewsaneha

Janus colloidal particles: preparation, properties, and biomedical applications.

Janus or anisotropic colloidal particles comprising of at least two components of different chemistry, functionality, and/or polarity have attracted attentions in a wide range of applications, e.g., in optics, magnetics, plasmonics, colloidal chemistry, and biomedicine. The interesting features of Janus colloidal particles are attributed to their tunable and controllable asymmetric structure, which allows controlling their physicochemical properties, down to the nanoscale. Moreover, their synergistic potential for multiplexing, multilevel targeting, and combination therapies make them particularly attractive for biomedical applications. However, the synthesis of Janus colloidal particles must be well-adapted to get particles with precise control of their various structural/physical/chemical properties. Nowadays, the advance in new fabrication processes is a strong need for fabricating compact composite particles with spatially separated functionalities, uniform size, tunable composition, and effective response to stimuli. In this review article, we summarized the most recent representative works on Janus colloidal particles including the various fabrication methods, important properties, and their potential applications, particularly in the biomedical field.

Immobilization of fluorescein isothiocyanate on magnetic polymeric nanoparticle using chitosan as spacer

The nanoparticle with simultaneous combination of magnetic and fluorescent properties was prepared by immobilization of fluorescein isothiocyanate (FITC) onto magnetic polymeric nanoparticle (MPNP). The MPNP with 41% magnetic content was obtained from incorporating Fe(3)O(4) magnetic nanoparticles (MNPs) into poly(styrene/divinyl benzene/acrylic acid) via the miniemulsion polymerization. Before labeling with FITC, the carboxylated MPNP was coated with chitosan (CS) having low, medium, or high molecular weight (MW) in order to avoid quenching of the fluorescent by iron oxide. Data obtained from TEM, size and zeta potential measurements clearly indicated the presence of CS as a shell surrounding the superparamagnetic MPNP core. The zeta potential, FTIR, and fluorescent spectroscopies confirmed the attachment of FITC to the MPNP-CS via covalent bonding. The higher MW or longer chains of CS (300kDa) offered the larger spacer with multiple sites for the FITC binding and, thus, provided the higher fluorescent emission intensity. The MPNP-CS immobilized with FITC would be useful for cell-labeling application.

Multifunctional Fluorescent-Magnetic Polymeric Colloidal Particles: Preparations and Bioanalytical Applications.

Fluorescent-magnetic particles (FMPs) play important roles in modern materials, especially as nanoscale devices in the biomedical field. The interesting features of FMPs are attributed to their dual detection ability, i.e., fluorescent and magnetic modes. Functionalization of FMPs can be performed using several types of polymers, allowing their use in various applications. The synergistic potentials for unique multifunctional, multilevel targeting nanoscale devices as well as combination therapies make them particularly attractive for biomedical applications. However, the synthesis of FMPs is challenging and must be further developed. In this review article, we summarized the most recent representative works on polymer-based FMP systems that have been applied particularly in the bioanalytical field.

Facile method for preparation of anisotropic submicron magnetic Janus particles using miniemulsion

Submicron hybrid magnetic, polystyrene (PS) based Janus particles containing magnetic nanoparticles (MNPs) on one side were successfully assembled using the miniemulsion/solvent evaporation method. Nanodroplets of styrene (St) monomer in the presence of PS and MNPs were generated in an aqueous continuous phase. The subsequent evaporation of St monomers resulted the precipitation of PS and MNPs into spherical nanoparticles. The effect of PS content, oil:water phase ratio, MNPs:PS ratio, and type and concentration of stabilizers on Janus morphology was investigated. A MNPs:PS weight ratio of 1:1 promoted the formation of Janus-like particles with MNPs located on one side due to the increased PS concentration during evaporation of the monomer solvent. Of the stabilizing agents tested (sodium dodecylsulfate (SDS), Triton X-405, polyvinyl alcohol, and Pluronic F-68), the presence of 1.0 g L(-1) SDS and 20.0 g L(-1) Pluronic F-68 was found to effectively stabilize hybrid particles with Janus morphology.

Fluorescent chitosan functionalized magnetic polymeric nanoparticles: Cytotoxicity and in vitro evaluation of cellular uptake

Nanoparticles possessing magnetic and fluorescent properties were fabricated by the covalent attachment of fluorescein isothiocyanate onto magnetic polymeric nanoparticles functionalized by chitosan. The synthesized magnetic polymeric nanoparticles-chitosan/fluorescein isothiocyanate were successfully used for labeling the living organ and blood-related cancer cells, i.e., HeLa, Hep G2, and K562 cells. The cytotoxicity test of nanoparticles at various incubation times indicated the high cell viability (>90%) without morphological change. The confocal microscopy revealed that they could pass through cell membrane within 2 h for K562 cells and 3 h for HeLa and Hep G2 cells and then confine inside cytoplasm of all types of tested cells for at least 24 h. Therefore, the synthesized magnetic polymeric nanoparticles-chitosan/fluorescein isothiocyanate would potentially be used as cell tracking in theranostic applications.

Composite Nanoparticles on the Natural Rubber Latex Glove for Reduction of Surface Friction and Cytotoxicity

Poly(methyl methacrylate) (PMMA) particles were deposited via the Layer-by-Layer technique onto sulphur prevulcanized natural rubber latex film grafted with polyacrylamide (SPNR-g-PAAm). Besides an increase in surface hardness and roughness, hence, decrease of the surface friction of SPNR glove, a direct contact between skin and rubber film was reduced. Consequently, it was expected that the allergic problem to certain sensitive individuals and cytotoxic potential caused by the leachable non-rubbers (proteins) and lubricant powder sprinkled onto SPNR glove would be lowered. The SPNR and SPNR-g-PAAm coated with PMMA particles were extracted by using the culture medium and subjected to the in vitro cytotoxicity evaluation on L-929 fibroblasts. Results showed that the cytotoxicity was effectively reduced by coating PMMA particles onto the grafted rubber film. In order to improve both the binding ability with SPNR and antimicrobial activity, the PMMA-chitosan core-shell particles were prepared for further depositing onto the non-grafted SPNR film. Moreover, the nanocapsules containing an aqueous core of disinfectant agent (chlorhexidine digluconate) and poly(methyl acrylate) or sulphur prevulcanized skim rubber shell were prepared for being embedded in SPNR glove.

Hybrid Fluorescent-Magnetic Polymeric Particles for Biomedical Applications

Submicron magnetic polymeric particle (MPP) and/or Janus magnetic polymeric particle (JMPP) were successfully prepared via the miniemulsion polymerization of styrene (St)/acrylic acid (AA) monomers consisting of superparamagnetic iron oxide nanoparticles (IONPs) coated with oleic acid. Since the particle nucleation occurs primarily within the monomer droplet, not only the size of particle could be controlled at the beginning but also its morphology was manipulated by using different types of initiator. The MPPs with homogeneous distribution of IONPs (41%) in P(St-DVB-AA) were obtained with using potassium persulfate (KPS) as initiator and divinyl benzene (DVB) as crosslinking agent. To obtain anisotropic JMPP, an oil-soluble initiator 2,2-azobis (2-isobutyronitrile) was used instead. The controllable phase separation between P(St-AA) and the encapsulated IONPs caused the stable spherical Janus particles containing IOPNs (15%) located on one side of polymer particle. Both MPPs and JMPPs could be easily separated by an external magnet. The MPPs were functionalized with chitosan (CS) acting as spacer and then chemical immobilized with fluorescein isothiocyanate (FITC) to produce fluorescent-MPPs. When applying as imaging device for cancer cells labeling i.e., HeLa, cells, results showed that MPPs/CS-FITC could be located inside cells with low cytotoxicity.

Composite Particles of Disinfectant Nanocapsules-Skim Rubber Latex

Skim latex, a by-product of natural rubber latex, was prevulcanized by sulfur and then used in the preparation of composite particles with disinfectant nanocapsules. Each polymeric nanocapsule contained chlorhexidine digluconate (CHD) as a disinfectant agent encapsulated with poly(methyl acrylate) (PMA) as a shell. The driving force for the heterocoagulation of CHD-PMA nanocapsule and sulfur-prevulcanized skim (SPVS) particle was the electrostatic interaction between the positive charge of lecithin residing on the surface of the nanocapsule and the negative charge from the indigenous surfactant (protein-lipid) and/or from sodium dodecyl sulfate on the surface of the SPVS latex particle. The zeta potential and morphology of heterocoagulated particles indicated the formation of the CHD-PMA/SPVS composite particles. Structures and formation mechanisms of the composite particles with different blend ratios were revealed by depth profiling confocal Raman spectra.