Cuttlefish Ink Tagged Photonic Crystal Particles and Their Ion-Responsive Construction.

Colloidal crystal materials have potential values in coding, sensing, displaying and so on. Attempts to promote these values tend to focus on the development of functional colloidal crystal materials with high color saturations and bright structural colors for practical applications. Thus, this work presented novel cuttlefish ink nanoparticles doped colloidal crystal particle material, which had distinguishable and high saturation colors, and could response to the electric field and pH obviously. It was also found that the doping could result in a short-range order and long-range disorder structure of the colloidal crystals, which endowed them with wide viewing angles. More importantly, by using electric field and ions dual-responsive hydrogel to replicate the composite colloidal crystals particles, the resultant cuttlefish ink nanoparticles doped inverse opal particles were imparted with the same high saturation vivid structural colors, as well as obviously structural color tunability. These features make the cuttlefish ink nanoparticles doped colloidal crystal particles ideal for many practical applications where structural color materials is needed.

eEF-2 Kinase-targeted miR-449b confers radiation sensitivity to cancer cells.

The roles of microRNA in regulation of various biological processes and in modulation of therapeutic effects have been widely appreciated. In this study, we found a positive correlation between miR-449 b expression and radiation sensitivity in cancer cells and in tumor specimens from patients. We showed that eEF-2 kinase, a negative regulator of global protein synthesis, is a target of miR-449 b. Introducing a miR-449 b mimic into cancer cells led to suppression of eEF-2 kinase expression, leading to increases of protein synthesis and depletion of cellular ATP. Further, we demonstrated that the miR-449 b mimic rendered the cancer cells more sensitive to ionizing radiation both in vitro (cell culture) and in vivo (animal xenograft model). Moreover, the radiation sensitivity conferred by miR-449 b could be blunted by cycloheximide, an inhibitor of protein synthesis, or by direct delivery of ATP liposome, supporting eEF-2 kinase as a mediator of the radio-sensitizing effects of miR-449 b. These results indicate that miR-449 b, which is frequently down-regulated in radio-resistant cancers, may represent a new critical determinant of radio-sensitivity.

Silencing of NAC1 Expression Induces Cancer Cells Oxidative Stress in Hypoxia and Potentiates the Therapeutic Activity of Elesclomol.

In order to survive under conditions of low oxygen, cancer cells can undergo a metabolic switch to glycolysis and suppress mitochondrial respiration in order to reduce oxygen consumption and prevent excessive amounts of reactive oxygen species (ROS) production. Nucleus accumbens-1 (NAC1), a nuclear protein of the BTB/POZ gene family, has pivotal roles in cancer development. Here, we identified that NAC1-PDK3 axis as necessary for suppression of mitochondrial function, oxygen consumption, and more harmful ROS generation and protects cancer cells from apoptosis in hypoxia. We show that NAC1 mediates suppression of mitochondrial function in hypoxia through inducing expression of pyruvate dehydrogenase kinase 3 (PDK3) by HIF-1α at the transcriptional level, thereby inactivating pyruvate dehydrogenase and attenuating mitochondrial respiration. Re-expression of PDK3 in NAC1 absent cells rescued cells from hypoxia-induced metabolic stress and restored the activity of glycolysis in a xenograft mouse model, and demonstrated that silencing of NAC1 expression can enhance the antitumor efficacy of elesclomol, a pro-oxidative agent. Our findings reveal a novel mechanism by which NAC1 facilitates oxidative stress resistance during cancer progression, and chemo-resistance in cancer therapy.

Responsive photonic barcodes for sensitive multiplex bioassay.

Barcodes have a demonstrated value for multiplex high-throughput bioassays. The tendency of this technology is to pursue high sensitivity target screening. Herein, we presented a new type of inverse opal-structured poly(N-isopropylacrylamide) (pNIPAM) hydrogel photonic crystal (PhC) barcodes with the function of fluorescent signal self-amplification for the detection. During the bio-reaction process at body temperature, the pNIPAM hydrogel barcodes kept swelling, and their inverse opal structure with interconnected pores provided unblocked channels for the targets to diffuse into the voids of the barcodes and react. During the detection process, the barcodes were kept at a volume phase transition temperature (VPTT) to shrink their volume; this resulted in an obvious increase in the density of fluorescent molecules and signal amplification. It was demonstrated that the responsive barcodes could achieve the limits of detection (LOD) of α-fetoprotein (AFP) and carcinoembryonic antigen (CEA) at 0.623 ng mL-1 and 0.492 ng mL-1, respectively. In addition, the proposed barcodes showed good multiplex detection capacity with acceptable cross-reactivity, accuracy, and reproducibility, and the results were consistent with those of common clinical laboratory methods for the detection of clinical samples. These features of the inverse opal-structured responsive hydrogel barcodes indicate that they are ideal technology for high-sensitive multiplex bioassays.

Boronate affinity molecularly imprinted inverse opal particles for multiple label-free bioassays.

Boronate affinity molecularly imprinted polymer inverse opal particles were developed for the multiplex label-free detection of glycoproteins with high sensitivity and specificity.