Search results for "drug carrier"

Polymeric Micelles and Liposomes as Potential Drug Carriers

1986

In the past, a whole aray of polymeric carriers for biologically active substances have been reported. In this field the main interest has focused on the use of randomly solubilized polymers. Naturally occuring amphiphilic transport proteins can be modelled by synthetic micellar solubilized polymers. Poly(ethylene oxide)-polypeptide block copolymers with hydrophobic and cyclophosphamide-containing side groups are described. These micellar systems are able to transport different hydrophobic drugs.

In situ gel forming graft copolymers of a polyaspartamide and polylactic acid: Preparation and characterization

2008

Abstract In situ gel forming systems have been prepared by linking polylactic acid (PLA) to a water soluble and polyfunctional polymer, such as α,β-poly( N -2-hydroxyethyl)- d , l -aspartamide (PHEA). Three graft copolymers PHEA–PLA with a different derivatization degree in PLA, have been synthesized and characterized. PHEA–PLA graft copolymer with the highest amount in PLA has been used to prepare solutions in organic solvents able to give rise to gel-like matrices when injected into phosphate buffered saline solution. The chemical degradation of these gels has been evaluated and in vitro tests have been performed to evaluate the cell compatibility of the hydrolysis products. The possibili…

Synthesis and bio-functionalization of magnetic nanoparticles for medical diagnosis and treatment

2011

The synthesis of multifunctional magnetic nanoparticles (NPs) is a highly active area of current research located at the interface between materials science, biotechnology and medicine. By virtue of their unique physical properties magnetic nanoparticles are emerging as a new class of diagnostic probes for multimodal tracking and as contrast agents for MRI. Furthermore, they show great potential as carriers for targeted drug and gene delivery, since reactive agents, such as drug molecules or large biomolecules (including genes and antibodies), can easily be attached to their surface. On the other hand, the fate of the nanoparticles inside the body is mainly determined by the interactions wi…

New Perspectives of HPMA-based Copolymers Derived by Post-Polymerization Modification

2014

Poly[N-(2-hydroxypropyl) methacrylamide] (HPMA) was one of the first polymers applied as polymer drug conjugate in the clinics. Since then many attempts have been made to expand the functionality of HPMA-based copolymers from advanced synthetic pathways to multiple biomedical applications. This Feature Article highlights multifunctional HPMA based copolymers prepared by controlled radical polymerization and subsequent post-polymerization modification of activated ester precursor polymers via aminolysis. This approach combines precise control of the polymer's microstructure (molecular weight, dispersity, block copolymer formation, end group functionalization) with an easy introduction of var…

pH-sensitive hydrogel based on a novel photocross-linkable copolymer.

2004

A pH sensitive hydrogel has been prepared by a UV irradiation technique. Starting polymer was the PHM (poly hydroxyethylaspartamide methacrylated) obtained from polyaspartamide (PHEA) partially derivatized with methacrylic anhydride (MA). This new copolymer has been further derivatized with succinic anhydride (SA) to obtain PHM-SA that has been cross-linked by UV irradiation to form a pH sensitive hydrogel. The network, recovered after washing as a powder, has been been characterized by FT-IR spectrophotometry and particle size distribution analysis. Moreover, to have information about water affinity of the prepared sample, swelling measurements have been carried out in aqueous media mimick…

Biocompatible Poly(N-isopropylacrylamide)-halloysite Nanotubes for Thermoresponsive Curcumin Release

2015

The grafting of poly(N-isopropylacrylamide) (PNIPAAM) onto the halloysite external surface is proposed in order to obtain a novel thermoresponsive drug carrier for curcumin delivery. The new nanomaterial is characterized by means of FT-IR spectroscopy, thermogravimetric analysis, and SEM investigations. A high density of polymer chain was achieved at the nanoparticle surface. The PNIPAAM dehydration phenomenon was observed in water above 32 °C that is nearly coincident with the lower critical solution temperature for the polymer. The colloidal stability as well as the wettability of the obtained nanomaterial may be triggered by temperature stimuli. In vitro tests simulating the gastro-intes…

New amphiphilic conjugates of mono- and bis(carboxy)-PEG(2,000) polymers with lipoamino acids as surface modifiers of colloidal drug carriers

2010

ChemInform Abstract: Multifunctional Poly(ethylene glycol)s

2011

In the rapidly evolving multidisciplinary field of polymer therapeutics, tailored polymer structures represent the key constituent to explore and harvest the potential of bioactive macromolecular hybrid structures. In light of the recent developments for anticancer drug conjugates, multifunctional polymers are becoming ever more relevant as drug carriers. However, the potentially best suited polymer, poly(ethylene glycol) (PEG), is unfavorable owing to its limited functionality. Therefore, multifunctional linear copolymers (mf-PEGs) based on ethylene oxide (EO) and appropriate epoxide comonomers are attracting increased attention. Precisely engineered via living anionic polymerization and d…

1987

Drug carriers were prepared by combining oligopeptidic sequences with synthetic polymeric chains. Soluble copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) were synthesized containing oligopeptidic side chains terminating in a drug model (p-nitroaniline). The susceptibility of these oligopeptidic sequences to degradation on incubation with lysosomal enzymes and human serum was evaluated by monitoring the p-nitroaniline liberation. It was shown that the drug model can be attached to the polymer carrier by means of an oligopeptidic spacer stable in blood serum and degradable after the polymer has been in contact with intracellular lysosomal enzymes. The studied polymer carriers were used…

Topical anti-inflammatory potential of quercetin in lipid-based nanosystems: In vivo and in vitro evaluation

2013

Purpose: To develop quercetin-loaded phospholipid vesicles, namely liposomes and PEVs (Penetration Enhancer-containing Vesicles), and to investigate their efficacy on TPA-induced skin inflammation. Methods: Vesicles were made from a mixture of phospholipids, quercetin and polyethylene glycol 400 (PEG), specifically added to increase drug solubility and penetration through the skin. Vesicle morphology and self-assembly were probed by Cryo-Transmission Electron Microscopy and Small/Wide Angle X-ray Scattering, as well as the main physico-chemical features by Light Scattering. The anti-inflammatory efficacy of quercetin nanovesicles was assessed in vivo on TPA-treated mice dorsal skin by the d…