Search results for "Mphi"

Development and In Vitro Evaluation of Lyotropic Liquid Crystals for the Controlled Release of Dexamethasone.

2017

Made available in DSpace on 2018-12-11T17:33:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-08-02 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) In this study, amphiphilic polymers were investigated as biomaterials that can control dexamethasone (DXM) release. Such materials present interfacial properties in the presence of water and an oily phase that can result in lyotropic liquid crystalline systems (LLCS). In addition, they can form colloidal nanostructures similar to those in living organisms, such as bilayers and hexagonal and cubic phases, which can be exploited to solubilize lipophilic drugs to sustain their release and enhance bioavailability. It was…

New amphiphilic poly(butadiene)-graft-poly(ethylene oxide)s

1995

Amphiphilic graft copolymers with a poly(butadiene) backbone and poly(ethylene oxide) side chains were synthesized by grafting isocyanateterminated poly(ethylene oxide) on to partially hydroxylated poly(butadiene). The graft copolymers are water soluble if the fraction of hydrophilic poly(ethylene oxide) exceeds 50 wt%. Solutions of graft copolymers in water and tetrahydrofuran were studied by static light scattering and viscosity measurements. By dynamic light scattering in solution it was shown that the graft copolymers form clusters.

Polyelectrolytes on block copolymer surfaces

2004

Soft lithography and properties of amphiphilic block copolymers are combined in a new technique for the generation of patterned substrates, which can be used in different ways as templates for further processing. In these processing steps the deposition of polyelectrolytes, metals and grafting from polymerizations are used for the construction of different structures.

Poly(styrene sulfonate) self-organization: electrostatic and secondary interactions

2004

We investigate the self-organization of PSS in brushes and polyelectrolyte multilayers with X-ray, neutron and optical reflectivity. The electrostatic force dominates brush phases and adsorption behavior, additionally we find evidence of a strong hydrophobic force: (i) within amphiphilic diblock copolymer monolayers, a PSS monolayer adsorbs flatly to the hydrophobic block, (ii) on temperature increase (and with screened electrostatic forces), more PSS is adsorbed onto oppositely charged surfaces, and (iii) a polyelectrolyte multilayers shrinks when heated at 100% r.h. The latter two effects are consistent with the well-known increase of the hydrophobic force on heating: The increased PSS su…

Studies on the solution behaviour of self-assembling polymeric systems

1993

Functional groups were attached to styrene-butadiene copolymers with different polymeric architectures and a low molecular weight compound. These polar stickers form binary, chelate-like contacts or extended juntion zones depending on their chemical nature. The solution properties of these amphiphilic species in toluene were studied by static light scattering.

Amphiphilic Graft Copolymers and Hyperbranched Polymers Based on (3-Vinylphenyl)azomethyl-malonodinitrile

2001

A convenient approach to amphiphilic hyperbranched polymers with thioether shell for the preparation and stabilization of coinage metal (Cu, Ag, Au) …

2014

Amphiphilic Poly(organosiloxane) Nanospheres as Nanoreactors for the Synthesis of Topologically Trapped Gold, Silver, and Palladium Colloids

2003

Amphiphilic poly(organosiloxane) nanospheres with different core−shell architectures are employed as passive nanoreactors for the synthesis of noble metal colloids. The amphiphilic poly(organosiloxane) nanospheres, which have diameters between 15 and 40 nm, possess a hydrophilic interior and a hydrophobic shell. Dispersed in organic solvents such as toluene, it has been achieved to transfer hydrophilic noble metal salts through the solvent into the nanospheres by either liquid−liquid or solid−liquid phase transfer. Subsequently, reduction of the noble metal salt with lithium triethylborohydride led to the formation of 2−5 nm sized noble metal colloids. If the network density of the shell of…

Synthesis of Amphiphilic Block Copolypept(o)ides by Bifunctional Initiators: Making PeptoMicelles Redox Sensitive.

2015

In this work, the synthesis of polypeptoid-block-polypeptide copolymers (block copolypept(o)ides) based on bifunctional initiators is described, which introduces a distinct chemical entity at the connection between both blocks. With a view towards redox-sensitive block copolypept(o)ides, a cystamine-based initiator was used to synthesize polysarcosine macroinitiators with degrees of polymerization (Xn) between 100 and 200 displaying monomodal molecular weight distributions and dispersities (Đ) around 1.1 as determined by size exclusion chromatography. Block copolypept(o)ides with a poly(γ-t-butyloxycarbonyl-L-glutamate) (PGlu(O(t) Bu)) block (Xn = 25 or 50) were synthesized by controlled N-…

HPMA Based Amphiphilic Copolymers Mediate Central Nervous Effects of Domperidone

2011

In this study we give evidence that domperidone encapsulated into amphiphilic p(HPMA)-co-p(laurylmethacrylate) (LMA) copolymer aggregates is able to cross the blood-brain barrier, since it affected motor behaviour in animals, which is a sensitive measure for CNS actions. Carefully designed copolymers based on the clinically approved p(HPMA) were selected and synthesized by a combination of controlled radical polymerization and post-polymerization modification. The hydrodynamic radii (R(h) ) of amphiphilic p(HPMA)-co-p(LMA) alone and loaded with domperidone were determined by fluorescence correlation spectroscopy.