The extremely low efficient cytosolic release of the internalized siRNA has emerged recently as a central issue for siRNA delivery, while there is a lack of guidelines to facilitate the cytosolic release of internalized siRNA. To address these concerns, we studied the contribution of the pH-sensitive inner core on handling the cytosolic release of siRNA delivered by a series of PG-P(DPAx-co-DMAEMAy)-PCB amphiphilic polycation nanomicelles (GDDC-Ms) with extremely low internalization (<1/4 of lipofactamine 2000 (Lipo2000)). Significantly, just by varying the mole ratio of DPA and DMAEMA to adjust the initial disassembly pH (pH) of the core near to 6.8, GDDC-Ms/siRNA could get nearly 98.8% silencing efficiency at w/w = 12 with 50 nM siRNA and ∼78% silencing efficiency at w/w = 30 with a very low dose of 5 nM siRNA in HepG-2 cell lines, while Lipo2000 only got 65.7% with 50 nM siRNA. Furthermore, ∼98.4% silencing efficiency was also realized in the hard-to-transfect human acute monoblastic leukemia cell line U937 by GDDC-Ms/siRNA (at w/w = 15, 50 nM siRNA), in the inefficient case for Lipo2000. Additionally, the high silencing efficiency (∼80%) in skin tissue in vivo was discovered. Undoubtedly, the robust potential of GDDC-Ms in handling the cytosolic release paves a simple but efficient new way for the design of the nonviral siRNA vector.

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mRNA is a novel class of therapeutic modality that holds great promise in vaccination, protein replacement therapy, cancer immunotherapy, immune cell engineering etc. However, optimization of mRNA molecules and efficient in vivo delivery are quite important but challenging for its broad application. Here we present an ionizable lipid nanoparticle (iLNP) based on iBL0713 lipid for in vitro and in vivo expression of desired proteins using codon-optimized mRNAs. mRNAs encoding luciferase or erythropoietin (EPO) were prepared by in vitro transcription and formulated with proposed iLNP, to form iLP171/mRNA formulations. It was revealed that both luciferase and EPO proteins were successfully expressed by human hepatocellular carcinoma cells and hepatocytes. The maximum amount of protein expression was found at 6 h post-administration. The expression efficiency of EPO with codon-optimized mRNA was significantly higher than that of unoptimized mRNA. Moreover, no toxicity or immunogenicity was observed for these mRNA formulations. Therefore, our study provides a useful and promising platform for mRNA therapeutic development.

Here we show that Gadd45a, a DNA damage-inducible protein that is regulated by tumor suppressors p53 and BRCA1, participates in the maintenance of centrosome stability. Mouse embryonic fibroblasts derived from gadd45a knock-out mice exhibit centrosome amplification (designated as increased centrosome numbers). Introduction of exogenous Gadd45a into mouse embryonic fibroblasts isolated from gadd45a-null mice substantially restored the normal centrosome profile. In contrast to p21 waf1/cip1 , which ensures coordinated initiation of centrosome, Gadd45a had no significant effect on centrosome duplication in S phase. Interestingly Gadd45a was found to physically associate with Aurora-A protein kinase, whose deregulated expression results in centrosome abnormality. Furthermore Gadd45a was demonstrated to strongly inhibit Aurora-A kinase activity and to antagonize Aurora-A-induced centrosome amplification. These findings identify a novel mechanism for Gadd45a in the maintenance of centrosome stability and broaden understandings of p53-and BRCA1-regulated signaling pathways in maintaining genomic fidelity.The essence of successful mitosis in mammalian cells is the generation of two genetically identical daughter cells. This requires the assembly of a strictly bipolar mitotic apparatus that will ensure that all daughter chromosomes are segregated to opposite sides of the cell before the completion of mitosis. This process is controlled by the centrosomes that organize the spindle poles during mitosis. In a manner similar to the chromosomal DNA of a cell, centrosomes replicate only once per cell cycle, generating two centrosomes, which then form the two poles of the mitotic spindle. If the centrosome duplicates more than once in a cell cycle then a multiple spindle may be assembled, and the chromosomes may be unequally distributed to the daughter cells, leading to genetic imbalances that generate genomic instability and produce cells with aggressive growth characteristics. Therefore, centrosome abnormalities may result in chromosomal missegregation and generation of aneuploidy, which are closely associated with cell transformation and tumorigenesis (1-4).Centrosome amplification has been linked to numerous genetic aberrations (5, 6), including the loss of the tumor suppressor protein p53 (7, 8) or disruption of its downstream target genes such as p21 (9, 10) and GADD45a (11). Mouse embryonic fibroblasts (MEFs) 3 derived from gadd45a-null mice display aneuploidy, chromosomal aberrations, gene amplification, and centrosome amplification (11). Other genetic alterations reported to affect centrosome numbers concern proteins involved in the response to DNA damage, including BRCA1 (12), BRCA2 (13), and ATR (14). In addition, several protein kinases have been implicated in the centrosome cycle, particularly in centrosome amplification. These include Aurora-A kinase, Aurora-B kinase (15-17), Polo kinase 1 (18 -20), and NIMA-related kinase 2 (21-23). It has been reported that overexpression of Aurora-A kinase results in centrosome...

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MXene-derived nanostructures provide the possibility of meeting the requirements of strong absorption, thin thickness and flexible layer for electromagnetic (EM) wave absorption. However, exploration of pure and well-intercalated MXene nanosheets for efficient EM wave absorption is still in the nascent stages. Herein, TiCT nanosheets with solvent-manipulated properties were achieved via ultrasonication-solvothermal treatment of bulk TiCT in different solvents including dimethylformamide (DMF), ethanol, and dimethyl sulfoxide (DMSO), respectively, because of their combined influences of molecular size, oxidation capability, and boiling point. Especially, it was found that a larger layer space and less oxidation effects on the TiCT nanosheets were observed upon solvothermal treatment in DMF than those in ethanol or DMSO treatment. As a result, the DMF-treated TiCT nanosheets can be used as highly effective dielectric materials for EM wave absorption. The reflection loss value reached -41.9 dB (more than 99.99%) at 13.4 GHz with the sample thickness of only 1.1 mm. Characterization techniques including scanning electron microscopy, transmission electron microscopy, atomic force microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and density functional theory calculation were used to elaborate the possible mechanisms.