Ming-Hao Yao

High transfection efficiency of quantum dot-antisense oligonucleotide nanoparticles in cancer cells through dual-receptor synergistic targeting.

Incorporating ligands with nanoparticle-based carriers for specific delivery of therapeutic nucleic acids (such as antisense oligonucleotides and siRNA) to tumor sites is a promising approach in anti-cancer strategies. However, nanoparticle-based carriers remain insufficient in terms of the selectivity and transfection efficiency. In this paper, we designed a dual receptor-targeted QDs gene carrier QD-(AS-ODN+GE11+c(RGDfK)) which could increase the cellular uptake efficiency and further enhance the transfection efficiency. Here, the targeting ligands used were peptides GE11 and c(RGDfK) which could recognize epidermal growth factor receptors (EGFR) and integrin ανβ3 receptors, respectively. Quantitative flow cytometry and ICP/MS showed that the synergistic effect between EGFR and integrin ανβ3 increased the cellular uptake of QDs carriers. The effects of inhibition agents showed the endocytosis pathway of QD-(AS-ODN+GE11+c(RGDfK)) probe was mainly clathrin-mediated. Western blot confirmed that QD-(AS-ODN+GE11+c(RGDfK)) could further enhance gene silencing efficiency compared to QD-(AS-ODN+GE11) and QD-(AS-ODN+c(RGDfK)), suggesting this dual receptor-targeted gene carrier achieved desired transfection efficiency. In this gene delivery system, QDs could not only be used as a gene vehicle but also as fluorescence probe, allowing for localization and tracking during the delivery process. This transport model is very well referenced for non-viral gene carriers to enhance the targeting ability and transfection efficiency.

Polypeptide-engineered physical hydrogels designed from the coiled-coil region of cartilage oligomeric matrix protein for three-dimensional cell culture

Photo-cross-linkable physical hydrogels based on the coiled-coil region of the cartilage oligomeric matrix protein and polyethylene glycol diacrylate were designed and synthesized to mimic the natural extracellular matrix for three-dimensional cell culture. The engineered polypeptides (Pcys and RGDPcys) were modified with polyethylene glycol diacrylate to form photo-cross-linkable multifunctional macromers via the Michael-type addition reaction between the cysteine residues and acrylates. Gel formation was confirmed by rheological measurements. The swelling ratio and stability of 10% w/v RGDP-PEG-acrylate6k hydrogel were 38% and 15 days, respectively. Spreading and migration of encapsulated fibroblast cells were observed in these physical hydrogels, while round cells were observed in a covalent control hydrogel. In addition, rapid self-healing of these physical hydrogels can provide a flexible way to build tissue by self-assembly and bottom-up approach. The results demonstrate that such physical hydrogels are expected to have great potential applications in tissue engineering.

An engineered coiled-coil polypeptide assembled onto quantum dots for targeted cell imaging

Quantum dot (QD)-polypeptide probes have been developed through the specific metal-affinity interaction between polypeptides appended with N-terminal polyhistidine sequences and CdSe/ZnS core-shell QDs. The size and charge of a QD-polypeptide can be tuned by using different coiled-coil polypeptides. Compared to glutathione-capped QDs (QD-GSH), QD-polypeptide probes showed an approximately two- to three-fold luminescence increase, and the luminescence increase was not obviously related to the charge of the polypeptide. QD-polypeptide probes with different charge have a great effect on nonspecific cellular uptake. QD-polypeptide probes with negative charge exhibited lower nonspecific cellular uptake in comparison to the QD-GSH, while positively charged QD-polypeptide probes presented higher cellular uptake than the QD-GSH. A targeted QD-ARGD probe can obviously increase targeted cellular uptake in α v β 3 overexpressing HeLa cells compared to QD-A. In addition, QD-polypeptide probes showed lower in vitro cytotoxicity compared to the original QDs. These results demonstrate that these QD-polypeptide probes with high specific cellular uptake, high fluorescence intensity and low background noise are expected to have great potential applications in targeted cell imaging.

Composite nanoparticle of Au and quantum dots for X-ray computed tomography and fluorescence dual-mode imaging in vivo

In this study, composite nanoparticles comprising Au nanoparticle and quantum dots were built and used for contrast-enhanced computed tomography imaging (CT) and fluorescence dual-mode imaging in vivo. The nanoparticle exhibited good monodispersity and good biocompatibility, and had excellent CT contrast-enhancement effect and fluorescence imaging capability. They were appropriate for being used as dual-mode imaging probe in vivo.