Safe fluorescent gene-transfection vectors are in great demand for basic biological applications and for gene-therapy research. Here, we introduce a new type of luminescent silicon nanoparticle (SiNP)-based gene carrier suitable for determining the intracellular fate of the gene vehicle in a long-term and real-time manner. The presented SiNP-based nanocarriers simultaneously feature strong and stable fluorescence, high DNA-loading capacity and gene-transfection efficiency, as well as favorable biocompatibility. Taking advantage of these unique benefits, we were able to readily observe the behavior of the gene carriers in live cells (e.g. cellular uptake, intracellular trafficking, and endosomal escape) in a long-term and real-time manner. The results demonstrate the potential usability of these fluorescent SiNP-based gene vectors as powerful tools in the field of gene therapy, and provide invaluable information for understanding the intracellular behavior of gene carriers.
The effects of butadiene/styrene ratio, monomer distribution, and molecular weight distribution and branching on the pressure sensitive adhesive properties of butadiene/ styrene radial teleblock copolymers are reported. Styrene content of polymers with varying structures shows a close relation with tack response, and styrene content and structure affect solution viscosity and shear adhesion. When part of the styrene is incorporated into the polybutadiene segment to yield a block progressively enriched in styrene (tapered block), solution viscosity and shear adhesion are reduced. When the butadiene segment is replaced by a block of randomly copolymerized butadiene and styrene, the polymers provide lower solution viscosities and shear adhesion but unchanged tack. The molecular weight distribution of the radial teleblock polymers can vary from broad, highly branched compositions to narrow molecular weight distributions of almost Iinear polymers. The latter have relatively high solution viscosity and low shear adhesion, whereas the former polymers produce moderate solution viscosity but high shear adhesion. Tack is generally unaffected. 相似文献
Microfabricated systems provide an excellent platform for the culture of cells, and are an extremely useful tool for the investigation of cellular responses to various stimuli. Advantages offered over traditional methods include cost-effectiveness, controllability, low volume, high resolution, and sensitivity. Both biocompatible and bio-incompatible materials have been developed for use in these applications. Biocompatible materials such as PMMA or PLGA can be used directly for cell culture. However, for bio-incompatible materials such as silicon or PDMS, additional steps need to be taken to render these materials more suitable for cell adhesion and maintenance. This review describes multiple surface modification strategies to improve the biocompatibility of MEMS materials. Basic concepts of cell-biomaterial interactions, such as protein adsorption and cell adhesion are covered. Finally, the applications of these MEMS materials in Tissue Engineering are presented. 相似文献
The related phenomena of biocompatibility and biodegradation are of major concern in the selection of synthetic polymers for use as implantable biomedical devices. These properties are largely determined by the consequences of the cellular interactions that occur at the polymer/tissue interface during inflammation. Using an in vivo cage implant system, in conjunction with surface analysis techniques, we have investigated the variation in the cellular events that occurred on a polyetherure-thaneurea and a cytotoxic polyvinyl chloride). Quantitative and qualitative information that describe the cellular response to polymer implantation will be presented. From the results, a chronological sequence has been established which suggests that the important events follow cellular adhesion, and include cell spreading over a polymer surface accompanied by lysosomal degranulation of the adherent cells. 相似文献
Biocompatible materials are of considerable interest in the development of cell/drug delivery carriers for therapeutic applications. This paper investigates the effects of the Bloom index of gelatin on its interaction with retinal pigment epithelial (RPE) cells. Following two days of culture of ARPE-19 cells with gelatin samples G75-100, G175, and G300, the in vitro biocompatibility was determined by cell proliferation and viability assays, and glutamate uptake measurements, as well as cytokine expression analyses. The mitochondrial dehydrogenase activity in the G300 groups was significantly lower than that of G75-100 and G175 groups. The Live/Dead assays also showed that the gelatin samples G300 induced mild cytotoxicity. In comparison with the treatment of gelatins with low Bloom index, the exposure to high Bloom strength gelatins markedly reduced the glutamate uptake capacity of ARPE-19 cells. One possible explanation for these observations is that the presence of gelatin samples G300 with high viscosity in the medium may affect the nutrient availability to cultured cells. The analyses of pro-inflammatory cytokine IL-6 expression at both mRNA and protein levels showed that the gelatins with low Bloom index caused less cellular inflammatory reaction and had more acceptable biocompatibility than their high Bloom strength counterparts. These findings suggest that the Bloom index gives influence on cellular responses to gelatin materials. 相似文献