Water Soluble Polymer Protected Lipofectamine 2000/DNA Complexes for Solid-Phase Transfection

Photoinduced Rapid Transformation from Au Nanoagglomerates to Drug-Conjugated Au Nanovesicles

Gold (Au) agglomerates (AGs) are reassembled using Triton X-100 (T) and doxorubicin (D) dissolved in ethanol under 185 nm photoirradiation to form TAuD nanovesicles (NVs) under ambient gas flow conditions. The positively charged Au particles are then electrostatically conjugated with the anionic chains of TD components via a flowing drop (FD) reaction. Photoirradiation of the droplets in a tubular reactor continues the photophysicochemical reactions, resulting in the reassembly of Au AGs and TD into TAuD NVs. The fabricated NVs are electrostatically collected onto a polished aluminum rod in a single-pass configuration. The dispersion of NVs is employed for bioassays to confirm uptake by cells and accumulation in tumors. The chemo-photothermal activity is determined both in vitro and in vivo. Different combinations of components are also used to fabricate NVs using the FD reaction, and these NVs are suitable for gene delivery as well. This newly designed gaseous single-pass process results in the reassembly of Au AGs for incorporation with TD without the need of batch wet chemical reactions, modifications, separations, or purifications. Thus, this process offers an efficient platform for preparing biofunctional Au nanostructures that requires neither complex physicochemical steps nor special storage techniques.

Substrate-mediated gene delivery from glycol-chitosan/hyaluronic acid polyelectrolyte multilayer films

Substrate-mediated transfection is one of the key strategies for localized gene delivery. Layer-by-layer (LbL) polyelectrolyte deposition is a promising technique which enables controlled delivery of a number of biofactors, including nucleic acids. Here, we embed lipoplexes containing plasmid DNA within polyelectrolyte multilayers composed of glycol-chitosan (Glyc-CHI) and hyaluronic acid (HA) in order to produce a film system that enables localized, surface-based transfection. The topography and morphology of the resulting multilayers were characterized after lipoplex absorption and during subsequent film build-up via atomic force microscopy (AFM) and scanning electron microscopy (SEM), respectively. DNA embedding efficiency and release were then examined. Lipoplex-containing Glyc-CHI/HA films were found to successfully transfect NIH3T3 fibroblasts and HEK293 kidney cells in vitro, maintaining transfection levels of approximately 20% for a period of at least 7 days.

Mannosylated liposomes for targeted gene delivery

Background

Liposomes can be modified with different ligands to control their biological properties, such as longevity, targeting ability, and intracellular penetration, in a desired fashion. The aim of this study was to modify liposomes with a novel mannosylated polyethylene glycol-phosphatidylethanolamine (M-PEG-PE) ligand to achieve active targeted gene delivery.

Methods

Rat Kupffer cells were isolated and used as model cells for in vitro evaluation of cytotoxicity and transfection efficiency. The modified liposomes were intravenously injected into the rats, and Kupffer cells were isolated and analyzed by flow cytometry for in vivo gene delivery and expression.

Results

The M-PEG-PE-modified liposome-enhanced green fluorescence protein plasmid (M-PEG-PE-Lipo-pEGFP) complexes had a particle size of 237 nm and a loading efficiency of 90%. The M-PEG-PE-Lipo-pEGFP complexes displayed remarkably higher transfection efficiency than unmodified Lipo-pEGFP, both in vitro (51%–30%) and in vivo (43%–27%).

Conclusion

M-PEG-PE could function as an excellent active targeting ligand, and M-PEG-PE-modified liposomes could be promising active targeted drug delivery vectors.

Development and evaluation of a novel nano-scale vector for siRNA

To synthesize a lipid-cationic polymer (LCP) containing brassidic acid side chain and to investigate its transfection efficiency and characteristics as a siRNA gene vector. The LCP was chemically synthesized and its nucleic acid binding capacity was determined by gel electrophoresis. HeLa-EGFP and TH1080-EGFP cell lines were transfected with siRNA against enhanced green fluorescent protein (EGFP) gene using a LCP to investigate the transfection efficiency. An MTT assay was performed to evaluate the cellular toxicity of the LCP vector. Its degradability and stability under acidic conditions were also investigated. The LCP vector possessed high DNA binding capacity. More than 73% of the cellular fluorescence was inhibited by the LCP-mediated transfection of siRNA against EGFP gene, indicating that vector had high transfection efficiency. Cellular viability was about 95% at the optimum transfection efficiency of LCP, suggesting that the cellular toxicity of LCP was very low. The LCP was also observed to be degradable; moreover, it could be easily stored at normal temperature. A gene vector used for the transfection of siRNA was successfully fabricated from synthesized LCP. Its numerous excellent properties entitle values for further scientific research.

Aliphatic polyester polymer stars: synthesis, properties and applications in biomedicine and nanotechnology

A critical review: the ring-opening polymerization of cyclic esters provides access to an array of biodegradable, bioassimilable and renewable polymeric materials. Building these aliphatic polyester polymers into larger macromolecular frameworks provides further control over polymer characteristics and opens up unique applications. Polymer stars, where multiple arms radiate from a single core molecule, have found particular utility in the areas of drug delivery and nanotechnology. A challenge in this field is in understanding the impact of altering synthetic variables on polymer properties. We review the synthesis and characterization of aliphatic polyester polymer stars, focusing on polymers originating from lactide, ε-caprolactone, glycolide, β-butyrolactone and trimethylene carbonate monomers and their copolymers including coverage of polyester miktoarm star copolymers. These macromolecular materials are further categorized by core molecules, catalysts employed, self-assembly and degradation properties and the resulting fields of application (262 references).