Search results for "polymerization"

1987

Preparation de vesicules contenant une matrice polymere reticule hydrophile (couches bimoleculaires phospholipides revetues de microparticules polymeres)

1981

In Vivo Gene-Silencing in Fibrotic Liver by siRNA-Loaded Cationic Nanohydrogel Particles

2015

Cationic nanohydrogel particles loaded with anti-Col1α1 siRNA suppress collagen synthesis and deposition in fibrotic mice: Systemically administered 40 nm sized nanogel particles accumulate in collagen-expressing cells in the liver. Their siRNA payload induces a sequence specific in vivo gene knockdown affording an efficient antifibrotic effect in mice with liver fibrosis.

Cationic Nanohydrogel Particles for Therapeutic Oligonucleotide Delivery.

2017

Short pharmaceutical active oligonucleotides such as small interfering RNA (siRNA) or cytidine-phosphate-guanosine (CpG) are considered as powerful therapeutic alternatives, especially to medicate hard-to-treat diseases (e.g., liver fibrosis or cancer). Unfortunately, these molecules are equipped with poor pharmacokinetic properties that prevent them from translation. Well-defined nanosized carriers can provide opportunities to optimize their delivery and guide them to their site of action. Among several concepts, this Feature Article focuses on cationic nanohydrogel particles as a universal delivery system for small anionic molecules including siRNA and CpG. Cationic nanohydrogels are deri…

Primary radical termination and chain transfer in vinyl polymerization

1974

Cyclodextrins in polymer synthesis: free radical polymerization of cyclodextrin host-guest complexes of methyl methacrylate or styrene from homogenou…

2000

The polymerization of methylated β-cyclodextrin (m-β-CD) 1 : 1 host-guest compounds of methyl methacrylate (MMA) (1) or styrene (2) is described. The polymerization of complexes 1 a and 2 a was carried out in water with potassium peroxodisulfate (K2S2O8)/sodium hydrogensulfite (NaHSO3) as radical redox initiator at 60°C. Unthreading of m-β-CD during the polymerization led to water-insoluble poly(methyl methacrylate) (PMMA) (3) and polystyrene (4). By comparison, analogously prepared polymers from uncomplexed monomers 1 and 2 in ethanol as organic solvent with 2,2′-azoisobutyronitrile (AIBN) as radical initiator showed significantly lower molecular weights and were obtained in lower yields i…

Noncovalent Targeting of Nanocarriers to Immune Cells with Polyphosphoester‐Based Surfactants in Human Blood Plasma

2019

Abstract Dendritic cells (DCs) are part of the immune system and can internalize pathogens by carbohydrate receptors. The uptake induces maturation and migration of the DCs resulting in an adaptive immune response by presenting antigens to T‐cells. Thus, targeted delivery to DCs is a powerful tool for immunotherapy. However, in blood, specific targeting is challenging as blood proteins adsorb to the nanocarriers and mask the targeting molecules. Additionally, covalent coupling of targeting groups to nanocarriers requires new chemistry for each nanocarrier, while a general strategy is missing. A general protocol by noncovalent adsorption of mannosylated polyphosphoesters (PPEs) on the nanoca…

Synthesis and In Vitro Evaluation of Defined HPMA Folate Conjugates: Influence of Aggregation on Folate Receptor (FR) Mediated Cellular Uptake

2010

In this article we report the synthesis and in vitro evaluation of well-defined, folate functionalized and fluorescently labeled polymers based on the clinically approved N-(2-hydroxypropyl)-methacrylamide (HPMA). The polymers were prepared applying the RAFT polymerization method as well as the reactive ester approach. The molecular weights of the polymers synthesized were around 15 and 30 kDa. The total content of conjugated folate varied from 0, 5, and 10 mol %. The cellular uptake of these polymers was investigated in the folate receptor (FR)-positive human nasopharyngeal epidermal carcinoma (KB-3-1) and FR-negative human lung epithelial carcinoma (A549) cancer cell lines. In FR-positive…

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…

New Magnetic Thin Film Hybrid Materials Built by the Incorporation of Octanickel(II)-oxamato Clusters Between Clay Mineral Platelets

2011

We report on a new method based on the combination of Langmuir-Schaefer deposition with self-assembly to insert highly anisotropic Ni(8) molecules in a hybrid organic-inorganic nanostructure. Spectroscopic, crystallographic, and magnetic data prove the successful insertion of the guest cationic molecule between templating clay platelets. These results open a new route toward the highly controlled fabrication of tailored functional organic-inorganic nanomaterials.