Transplantation of nanoparticle transfected skeletal myoblasts overexpressing vascular endothelial growth factor-165 for cardiac repair.

Background: We investigated the feasibility and efficacy of polyethylenimine (PEI) based human vascular endothelial growth factor-165 (hVEGF165) gene transfer into human skeletal myoblasts (HSM) for cell based delivery to the infarcted myocardium.

Methods And Results: Based on optimized transfection procedure using enhanced green fluorescent protein (pEGFP), HSM were transfected with plasmid-hVEGF165 (phVEGF165) carried by PEI (PEI-phVEGF165) nanoparticles. The transfected HSM were characterized for transfection and expression of hVEGF165 in vitro and transplanted into rat heart model of acute myocardial infarction (AMI): group-1=DMEM injection, group-2= HSM transplantation, group-3= PEI-phVEGF165-transfected HSM (PEI-phVEGF165 myoblast) transplantation.

Multi-functional chitosan nanoparticles encapsulating quantum dots and Gd-DTPA as imaging probes for bio-applications.

Chitosan was used to encapsulate both CdSe/ZnS quantum dots (QDs) and the magnetic resonance imaging (MRI) contrast agent gadolinium-diethylenetriaminepentaacetate (Gd-DTPA), forming multi-functional nanoparticles that can be used in a wide range of in vitro or in vivo studies as fluorescent biological labels as well as MRI contrast agents, respectively. Multi-color QDs at pre-determined molar ratios were encapsulated into chitosan nanoparticles to produce bar-coding fluorescent labels. The encapsulated QDs and Gd-DTPA still maintained their desirable optical properties and relatively high relaxivity, respectively.

Ultrafine biocompatible chitosan nanoparticles encapsulating multi-coloured quantum dots for bioapplications.

Owing to their excellent optical properties, luminescent semi-conductor quantum dots (QDs) have proven themselves to be an attractive choice in biological labeling. However, there exists the concern of cytotoxicity in using these heavy metal-based nanoparticles as molecular probes. In order to improve their general biocompatibility, CdSe/ZnS QDS are encapsulated in the natural biopolymer chitosan, forming monodisperse chitosan nanoparticles in the range of 60 nm in 1 single step.

Quantum-dot based nanoparticles for targeted silencing of HER2/neu gene via RNA interference.

Gene silencing using short interfering RNA (siRNA) is fast becoming an attractive approach to probe gene function in mammalian cells. Although there have been some success in the delivery of siRNA using various methods, tracking their delivery and monitoring their transfection efficiency prove to be hard without a suitable tracking agent. Therefore, a challenge lies with the design of an efficient and at the same time, self-tracking, transfection agent for RNA interference.

Surface modification of gold and quantum dot nanoparticles with chitosan for bioapplications.

Gold (Au) and quantum dot (QD) nanoparticles, which have been extensively used in many fields, were encapsulated with a natural polymer, chitosan, to improve their biocompatibility. Characterization was performed using ultraviolet-visible, dynamic light scattering, atomic force microscopy, and transmission electron microscope analyses. It was found that a Au/chitosan ratio of 1:1 and smaller produced chitosan-encapsulated Au nanoparticles of a sufficiently small size, and this result was then applied in the chitosan encapsulation of QDs.

Creating new supramolecular materials by architecture of three-dimensional nanocrystal fiber networks.

The architecture of three-dimensional interconnecting self-organized nanofiber networks from separate needlelike crystals of L-DHL (lanosta-8,24-dien-3beta-ol:24,25-dihydrolanosterol = 56:44) in di-isooctylphthalate has been achieved for the first time, on the basis of the completely new concept of branching creation by additives (branching promoters). [In this work, an additive, ethylene/vinyl acetate copolymer (EVACP), is used at a concentration of several 10 ppm.] We demonstrate that this novel technique enables us to produce previously unknown self-supporting supramolecular functional materials with tailormade micro- or nanostructures, possessing significantly modified macroscopic properties, by utilizing materials thus far considered to be "useless".