Solid polymer nanoparticles

Another area where biodegradable polymeric drug carriers have been found promising is oral vaccines. There are several reasons for this. First, stomach acidity causes rapid degradation of the compounds typically used for immunization, such 

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Figure 14.9 Schematic of the process of preparing polymer nanoparticles and films via a miniemulsion route, (a) First, a solution of the polymer in an organic solvent is mixed with water containing an appropriate surfactant. A miniemulsion is then formed on stirring and ultrasonication. Finally, the solvent is evaporated, resulting in solid polymer nanoparticles dispersed in water.

Evaporation of volatile byproducts and solvents is often used to obtain the solid metal nanoparticles. The residue may contain metal nanoparticles and protective reagents. When the nanoparticles are well protected by ligands or polymers, then the solid residues can be dispersed again without coagulation of the particles. When the nanoparticles are not well protected, however, the evaporation often results in aggregation of the nano-particles. 

Synthesis and Characterisation of Molecularly Imprinted Polymer Nanoparticles for Streptomycin for Use as Solid Phase Extraction Materials... 

The direct electrochemical deposition methods for the preparation of electrocatalysts allow to localize the catalyst particles on the top surface of the carbon support, as close as possible to the solid polymer electrolyte and does not need heat (oxidative and/or reducing) treatment, as most of the chemical methods do, in order to clean the catalytic particles from surfactant contamination [27,28], This will prevent catalyst sintering due to the agglomeration of nanoparticles under thermal treatment. 

Ten milligrams of the Step 3 product were dissolved in 1 ml of dimethyl sulfoxide and then removed by freeze-drying. Thereafter 1 ml of 10% sucrose was added to the hydrate, and the freeze-dried solids were re-dissolved to form a suspension. After ultra-sonicating for 10 minutes, polymer nanoparticles were formed. 

Oil and water [oil-in-water (0/W) or water-in-oil (W/0)] emulsions are utilized for the production of nanoparticle dispersions. The colloidal emulsions are stabilized by a film of surfactants and polymers, which interact with the oil and water phases to prevent aggregation and droplet growth. These microemulsions are typically used as templates for the production of nanoparticles and solid lipid nanoparticles (SLN). 

Polymer nanoparticles with diameters of 50-500 nm are now widely used. As with microspheres and microcapsules, one can differentiate between solid polymeric spheres (nanoparticles) and those spheres with thin polymeric walls (nanocapsules). The locus of polymerisation is not an emulsion droplet as in microencapsulation, hut a micelle. The process involves the soluhilisation of a water-soluhle monomer such as acrylamide along with the dmg or other agent such as antigen to he encapsulated. An organic liquid such as n-hexane serves as the outer phase. Polymerisation is induced hy irradiation (y-rays. X-rays, UV light), exposure to visible light or heating with an initiator. 

There are distinct methods to improve the enzyme stability either by simple coating of enzymes by ILs or by noncovalent adsorption or by covalent linking of the enzymes with the solid supports such as polymers, nanoparticles, carbon nanotubes, and encapsulation in hydrogels. One of the interesting and new features of ILs as an immobilization support for enzymes evolved out of its incompetence for retaining... 

Subsequent reduction of the metal complexes in the solid polymer affords the metal particles. The result is the selective concentration of the nanoparticles in selected areas. ... 

BBS, blood-brain barrier LDL, low-density lipoprotein PLN, polymer-lipid hybrid nanoparticles SLN, solid lipid nanoparticles. 

PANI-NTs synthesized by a template method on commercial carbon cloth have been used as the catalyst support for Pt particles for the electro-oxidation of methanol [501]. The Pt-incorporated PANl-NT electrode exhibited excellent catalytic activity and stabUity compared to 20 wt% Pt supported on VulcanXC 72R carbon and Pt supported on a conventional PANI electrode. The electrode fabrication used in this investigation is particularly attractive to adopt in solid polymer electrolyte-based fuel cells, which arc usually operated under methanol or hydrogen. The higher thermal stabUity of y-Mn02 nanoparticles-coated PANI-NFs on carbon electrodes and their activity in formic acid oxidation pomits the realization of Pt-free anodes for formic acid fuel cells [260]. The exceUent electrocatalytic activity of Pd/ PANI-NFs film has recently been confirmed in the electro-oxidation reactions of formic acid in acidic media, and ethanol/methanol in alkaline medium, making it a potential candidate for direct fuel cells in both acidic and alkaline media [502]. 

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