Polymer microparticle

Won, J., Inaba, T., Masuhara, H., Fujiwara, H., Sasaki, K, Miyawaki, S. and Sato, S. (1999) Photofhermal fixation of laser-trapped polymer microparticles on polymer substrates. Appl. Phys. Lett., 75, 1506-1508. 

CR Robert, PA Buri, NA Peppas. Effect of degree of crosslinking of water transport in polymer microparticles. J Appl Polym Sci 30 301-307, 1985. 

Morales, M.E., Ruiz, M.A., Oliva, I., Oliva, M. and Gallardo, V. (2007) Chemical characterization with XP S of the surface of polymer microparticles loaded with morphine. International Journal of Pharmaceutics, 333, 162—166. 

A very recent development is encapsulation of actives in colloidosomes [16, 41]. The method is analogous to liposome entrapment. Selectively permeable capsules are formed by surface-tension-driven deposition of solid colloidal particles onto the surface of an inner phase or active ingredient in a water-in-oil or an oil-in-water emulsion composed of colloidal particles. Initially synthetic polymer microparticles were used but more recently a natural alternative has been described based on small starch particles. After spray-drying, redispersible emulsions can be formed. 

However, a study of a few dyes of higher fluorescence quantum yield in polymer microparticles did not show any change in the fluorescence lifetime even though the modification of the fluorescence spectra was observed [4]. In this work, a new molecule (9-amino acridine hydrochloride hydrate, 9AAHH) is reported in which we have observed the effect of MDR in both, the steady state spectra and the fluorescence lifetimes. The dephasing time of 9AAHH in polymer matrix at room temperature have been determined from this study. 

Lu, L., Stamatas, G. N., and Mikos, A. G (2000), Controlled release of transforming growth factor beta 1 from biodegradable polymer microparticles,/. Biomed. Mater. Res., 50,440—451. 

Davis, S. S. (2005), The use of soluble polymers and polymer microparticles to provide improved vaccine responses after parenteral and mucosal delivery, Vaccine, 24, Suppl. 2, S7-S10. 

Mikos and Peppas described the flow channel to measure the bioadhesion of polymer microparticles on mucin gels. Later Lehr et al. ° used an in situ loop model in the rat for the investigation of mucoadhesive microspheres (Fig. 3). They concluded that this approach allowed the study of the transit of particles. Another technique to study the mucoadhesive properties of microspheres is the electrobalance method, as... 

Drug release from biodegradable polymer microparticles is determined by the polymer degradation kinetics, structural features of the microparticles, and distribution of the drugs within the particle matrix. The ultimate goal of microparticle systems in the controlled drug delivery is to achieve readily tunable release profiles, which has been pursued in various perspectives. 

Polymer microparticles have attracted much attention for drug delivery applications. Traditional microparticle... 

Compared to conventional polymer microparticle fabrication methods, microfabrication offers greater... 

Guan, J. Lee, L.J. Hansford, D.J. Layered thin-film polymer microparticles fabricated by soft lithography. To be submitted to chemistry of marterials. 

Mawson S, Johnston KP, Betts DE, McClain JB, DeSimone JM. Stabilized polymer microparticles by precipitation with a compressed fluid antisolvent. I. Poly(fluoro acrylates). Macromolecules 1997 30, 71-77. 

Protein stability during encapsulation in biodegradable polymer microparticles has been reviewed in detail [6,23,27], In comparison, little information is available on lipid materials. However, conditions causing stability problems are not specific for polymer microparticle formulations. Lipids, being a hydrophobic material like many biodegradable polymers, may involve similar processing parameters [22,28],... 

T. Nisisako and T. Torii, Formation of biphasic Janus droplets in a micro-fabricated channel for the synthesis of shape-controlled polymer microparticles. Advanced Materials, 19, 1489—l-, (2007). 

Fig. 35. Schematic representation of formation of cohesive precipitate . Shown (left) is the emulsion with electrostatically stabilized polymer microparticles with extended surface bound sodium alginate chains. Shown (right) is the cohesive precipitate containing destabilized microparticles with collapsed surfactant and with some (assumed) ionotropic bridging chains...

Evaluate Supercritical carbon dioxide is a liquid form of CO2 used in the food industry to decaffeinate tea, coffee, and colas, as well as in the pharmaceutical industry to form polymer microparticles used in drug delivery systems. Use Figure 12.36 to determine what conditions must be used to form supercritical carbon dioxide. 

Besides the synthesis of bulk polymers, microreactor technology is also used for more specialized polymerization applications such as the formation of polymer membranes or particles [119, 141-146] Bouqey et al. [142] synthesized monodisperse and size-controlled polymer particles from emulsions polymerization under UV irradiation in a microfluidic system. By incorporating a functional comonomer, polymer microparticles bearing reactive groups on their surface were obtained, which could be linked together to form polymer beads necklaces. The ability to confine and position the boundary between immiscible liquids inside microchannels was utilized by Beebe and coworkers [145] and Kitamori and coworkers [146] for the fabrication of semipermeable polyamide membranes in a microfluidic chip via interfacial polycondensation. 

After this first report of NIR electroluminescence using Er hydroxyquinolinate, H. Suzuki et al. investigated the luminescence characteristics of this complex under different sample forms which can further be used as NIR emissive materials. Three types of samples have been prepared vacuum-deposited thin-films, doped spin-coated IR polymer films and doped polymer microparticles (Suzuki et al., 2003). Typical NIR luminescence of the Er ion was observed at 1.55 pm for each sample form and with higher intensities when excitation was performed in the ligand absorption bands instead of directly in the Er excited levels. This clearly indicates that sensitization of Er -centered luminescence occurs through ligand-to-metal energy transfer. For the doped monodispersed PMMA microparticles the lower lumi-... 

Savolainen M, Herder J, Khoo C, Lovqvist K, Dahlqvist C, Glad H, Juppo AM (2003) Evaluation of polar lipid-hydrophilic polymer microparticles. International Journal of Pharmaceutics 27 262(1-2) 47-62. 

Q. Xu, M. Hashimoto, T. Dang, T. Hoare, D. Kohane, G. Whitesides, and R. Danger, Preparation of monodisperse biodegradable polymer microparticles using a microfluidic flow-focusing device for controlled drug delivery, Small, 5, 1575-1581, 2009. 

Val Valette, L., Pascault, J.-P., Magny, B. Use of functional (meth)acrylic cross-linked polymer microparticles as toughening agents for epoxy/diamine thermosets. Macromol. Mater. Eng. 288 (2003) 867-874. 

Saurer, E.M., et al. Assembly of erodible, DNA-containing thin films on the surfaces of polymer microparticles Toward a layer-by-layer approach to the delivery of DNA to antigen-presenting cells. Acta Biomaterialia 5(3), 913-924 (2009)... 

Inertial microfiuidic devices are typically characterized using neutrally buoyant polymer microparticles prior to any experimentation with cells. The use of microparticles offers a number of advantages, including greater robustness than cells, ease of preparation of solutions with desired concentrations, and ability to reuse solutions for visualization experiments to reduce experimental costs. Furthermore, microparticles are commercially available in a wide range of sizes (from nm to pm) which makes it possible to closely match their size with size of cells that will ultimately be separated in the devices. Finally, as discussed in the subsequent sections, microparticle streak... 

Chitosan-based nano- and microparticles are widely used for fabrication of controlled dmg release systems. Numerous studies have demonstrated that chitosan and its derivatives (A-trimethyl chitosan, mono-A-carboxymethyl chitosan, etc.) are effective and safe for absorption enhance to improve mucosal (nasal, peroral) delivery of hydrophylic macromolecules, such as peptide and protein dmgs as well as heparins [37,38]. This absorption enhancing effect of chitosan is caused by the opening of intercellular tight junctions, thereby favoring the paracellular transport of macro-molecular dmgs. Recently, a series of successful model chitosan-based polymer systems for mucosal dmg delivery have been reported. Thus, Lim et al. [39] have proposed novel polymer microparticles based on combination of hyaluronic acid and chitosan hydroglutamate... 

G.R. Ferreira, T. Segura, F.G. de Souza Jr., A.P. Umpiene, F. Machado, Synthesis of poly(vinyl acetate)-based magnetic polymer microparticles, European Polymer Journal 48 (2012) 2050-2069. 

The ubiquitous temperature effects on luminescent sensors can be referenced and compensated with dual luminophore preparatiOTis. Several approaches of dual optical sensors have been demonstrated, that can be used for simultaneous determination of oxygen and temperature, or CO2 and temperature, respectively [114,115]. Luminescent temperature indicators have also been employed as reference components in PSPs (see Sect. 3.1). These have foimd widespread application in fluid mechanics and aerodynamic wind tunnel tests. The real-time imaging of dynamic flow processes on model surfaces are of high significance for aerospace and car industry. To avoid interferences or energy transfer between the oxygen and temperature sensitive dyes, these can be incorporated into different types of polymer microparticles [116]. 

Petrov et al. (2006) stndied porons biodegradable polymer microparticles (with PLGA, 51-62 kDa, 21 samples) designed as devices for drng delivery in depot formulations nsing NMR cryoporometry (with kQj=50 K nm) method. The main PSD peak for all samples was at 60-100 nm. There was no comparison of the NMR cryoporometry results with other methods. SEM images were of low resolution to analyze the porosity of polymer particles. 

---