"Hook&Loop" multivalent interactions based on disk-shaped nanoparticles strengthen active targeting.

How to enhance active targeting efficiency remains a challenge. Multivalent interactions play a crucial role in improving the binding ability between ligands and receptors. It is hypothesized that nanoparticles bearing a flat conformation attain simultaneous formation of multiple ligand-receptor bindings, which could be vividly metaphorized by the "Hook&Loop" rationale. In this study, spherical, rod-shaped and disk-shaped folic acid-modified red blood cell membrane-coated biomimetic mesoporous silica nanoparticles (FRMSNs) were prepared to verify the shape-based multivalent interactions. The fundamental concepts of multivalent interactions have been proved by a series of both in vitro and in vivo evaluations. Physical characterization confirmed the morphology, shape and surface features of FRMSNs. Strengthened binding and internalization of disk-shaped FRMSNs by K562 cells stresses the merits of multivalent interactions. Whereas Bio-TEM visually demonstrates the proposed "plane" contact of disk-shaped particles with cells, quantification further confirmed strengthened "plane" binding affinity with folate binding proteins owing to multivalent interactions. In K562 xenograft mice, doxorubicin-loaded disk-shaped FRMSNs effectively slowed down chronic myeloid leukemia progression. It is concluded that disks favor multivalent interactions which leads to enhanced active targeting efficiency.

A fatigue-resistant microcable for small diameter leads of active implantable medical devices.

Reliability is a key-but-challenging requirement of active implantable medical devices. Implanted medical devices, such as leads, are exposed to tough environments in terms of corrosion and movement. Alongside good reliability, there is also a need for the size of medical implants to be reduced, both to minimize trauma and to enable sites that have hitherto been inaccessible to be reached, such as the tortuous venous collateral network of the left ventricle. Finally, specific electrical properties are required to adequately stimulate or sense specific regions within the human body. In this work, we present a composite microcable that combines small size with high electrical performance and long-term lead robustness. Combining multiple individually insulated electrical conductors in a microcable structure is perfectly suited for leads with multiple selectively contacted electrodes. The use of fine wires of 19 µm diameter enables the manufacture of a 7 × 7 microcable with an extremely small total diameter of less than 0.3 mm. In addition, the fine wires are composed of a core-shell metal-to-metal composite, which allows multiple advantages in one microcable: good X-ray visibility, high electrical conductivity, and very high fatigue resistance. The new MP35N®-Pt composite wire exhibits very strong lead robustness with good electrical conductivity. The fatigue test results presented were obtained by applying 90° bending under tensile load and show that the microcable has a 35-fold increase in high cycle fatigue robustness compared to standard PtIr20 leads. The resulting fracture surfaces were analyzed with scanning electron microscopy. Complementary results from conductivity measurements, X-ray visibility tests and mechanical testing have also been presented to illustrate the benefits of this newly developed composite microcable compared to state-of-the-art electrical conductors for medical implant applications.

Influence of patient characteristics on chimeric antigen receptor T cell therapy in B-cell acute lymphoblastic leukemia.

CD19-specific chimeric antigen receptor T cell (CD19 CAR T) therapy has shown high remission rates in patients with refractory/relapsed B-cell acute lymphoblastic leukemia (r/r B-ALL). However, the long-term outcome and the factors that influence the efficacy need further exploration. Here we report the outcome of 51 r/r B-ALL patients from a non-randomized, Phase II clinical trial (ClinicalTrials.gov number: NCT02735291). The primary outcome shows that the overall remission rate (complete remission with or without incomplete hematologic recovery) is 80.9%. The secondary outcome reveals that the overall survival (OS) and relapse-free survival (RFS) rates at 1 year are 53.0 and 45.0%, respectively. The incidence of grade 4 adverse reactions is 6.4%. The trial meets pre-specified endpoints. Further analysis shows that patients with extramedullary diseases (EMDs) other than central nervous system (CNS) involvement have the lowest remission rate (28.6%). The OS and RFS in patients with any subtype of EMDs, higher Tregs, or high-risk genetic factors are all significantly lower than that in their corresponding control cohorts. EMDs and higher Tregs are independent high-risk factors respectively for poor OS and RFS. Thus, these patient characteristics may hinder the efficacy of CAR T therapy.

MicroRNA-294 Promotes Cell Proliferation, Migration and Invasion in SMMC-7721 Hepatoma Carcinoma Cells by Activating the JNK/ERK Signaling Pathway.

BACKGROUND: It has been reported that miR-294 is highly expressed in hepatocellular carcinoma (HCC) tissues and cells. However, the potential role of miR-294 in the pathogenesis of HCC remains unclear. This study aimed to explore the role of miR-294 in HCC and the potential mechanism involved in this process. MATERIALS AND METHODS: Reverse transcription polymerase chain reaction was performed to determine the expression of miR-294 in HCC tissues and cell lines. Following the overexpression or knockdown of miR-294, the proliferation, migration, and invasion abilities of cells were determined using Cell Counting Kit-8 (CCK-8), wound healing and transwell assays, respectively. The phosphorylation of JNK and ERK was determined through western blotting. Furthermore, HCC cells were treated with JNK inhibitor SP600125 or ERK inhibitor U0126 and transfected with miR-294 mimics or negative control. Subsequently, the phosphorylation of JNK and ERK was evaluated and the proliferation, migration and invasion abilities of HCC cells were also determined. RESULTS: The expression of miR-294 was significantly increased in HCC tissues and cell lines. Following the overexpression of miR-294, proliferation, migration, and invasion were promoted in the SSMC-7721 cell line, and the phosphorylation of JNK and ERK was increased, while silencing of miR-294 led to the opposite result. Use of the JNK or ERK inhibitor to treat SSMC-7721 cells transfected with miR-294 mimics decreased the phosphorylation of JNK and ERK and inhibited the proliferation, migration and invasion abilities of cells. CONCLUSIONS: miR-294 is important for the development of HCC in terms of the biological activities of cells, and may be a novel therapeutic target for HCC.

Fatigue behavior in Co-Cr-Ni-Mo medical wires drawn with different drawing practices.

35%Co-20%Cr-35%Ni-10%Mo alloy (MP35N) with a low titanium (LT) content is commonly used as the material for the manufacture of leads in medical applications such as Cardiac Rhythmic Management (CRM), neurostimulation and Deep Brain Stimulation (DBS). The material is drawn to thin wires, and this involves subjecting the material to extensive plastic deformation to obtain the desired mechanical and fatigue properties. The critical part in the medical device design requires understanding the relationship between the processing method, microstructure and their impact on the cyclic performance. In this study, the influence of drawing practices namely Full Die Drawing (FDD) and Half Die Drawing (HDD) on the cyclic performance of MP35NLT wires have been investigated, by differing the amount of plastic strain applied on the material. The as-drawn wires were subjected to rotary beam fatigue tests (R = -1) with varying stress amplitudes, and the microstructural factors controlling the Low Cycle Fatigue (LCF) and High Cycle Fatigue (HCF) performance were determined through post fatigued TEM investigations. The results conclude that there is a significant impact on the drawing techniques on the fatigue performance of MP35NLT wires, with the FDD wires having a higher endurance limit than the HDD drawn wire until 75% CW, but there was a slight drop in the fatigue performance when the CW was increased to 95%. This was attributed to the difference in grain sizes, dislocation structures, twin density, twin spacing, and grain boundary orientations observed between the two wires which contributed to contrasting cyclic behavior. The drop-in fatigue performance of the FDD wire upon an increased strain to 95% has been attributed to the shear band formations in the material, which increased the stress localization in the material bestowing to drop-in fatigue performance.

RNA-Binding Motif 4 (RBM4) Suppresses Tumor Growth and Metastasis in Human Gastric Cancer.

BACKGROUND Dysregulation of the splicing activator, RNA-binding motif 4 (RBM4), has recently been reported to be involved in the progression of several cancers. However, the mechanisms that underpin the activity of RBM4 in gastric cancer (GC) remain unknown. The purpose of our study was to explore how RBM4 affects the biological behavior of GC through in vivo and in vitro experiments. MATERIAL AND METHODS Western blot and flow cytometry analyses were used to investigate the RBM4 protein levels in normal gastric epithelial cells and 5 types of GC cells. Cell Counting Kit-8 assay, flow cytometry analysis, wound-healing, and migration and invasion assays were evaluated in vitro in BGC823 and MGC803 GC cells. A xenograft tumor model was used to assess whether RBM4 inhibits GC growth in vivo. Mitogen-activated protein kinase (MAPK) protein levels were determined using western blot analyses. RESULTS Our study revealed that RBM4 protein was downregulated in GC cells. Re-expression of RBM4 inhibited the proliferation, migration, and invasion of GC cells, while promoting apoptosis. Thus, the overexpression of RBM4 can inhibit tumor growth in GC mouse models. We also report that RBM4 was involved in the activation of MAPK-dependent signaling pathways in human GC. CONCLUSIONS It is hoped that these findings will improve our understanding of GC pathogenesis while also helping us to explore the feasibility of RBM4-targeted therapy for GC treatment.

Studies on the in vitro and in vivo degradation behavior of amino acid derivative-based organogels.

The in vitro degradation behavior of organogel with different gelators based on amino acid was investigated in detail. Two methods were applied in this research: weighting method and high-performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD) method, which was established for the first time. Their degradation behaviors in vivo were investigated by varying the kind and concentration of gelators via subcutaneous implantation. The results showed that the stronger the gelation ability or the higher the gelator concentration, the slower the degradation rate of organogel. Moreover, the organogel prepared by oils with longer alkyl length degraded slower than that of the shorter ones, which also decreased in thermal stability and mechanical strength. The investigation on degradation process showed that the degradation rate was mainly controlled by the collapse of network structure formed by gelators. In conclusion, organogel had a tunable degradation rate through altering the gelator type, oil type and the gelator concentration. It remains a promising candidate for subcutaneous in-situ implant as drug delivery vehicle.

RNA methyltransferase NSUN2 promotes stress-induced HUVEC senescence.

The tRNA methyltransferase NSUN2 delays replicative senescence by regulating the translation of CDK1 and CDKN1B mRNAs. However, whether NSUN2 influences premature cellular senescence remains untested. Here we show that NSUN2 methylates SHC mRNA in vitro and in cells, thereby enhancing the translation of the three SHC proteins, p66SHC, p52SHC, and p46SHC. Our results further show that the elevation of SHC expression by NSUN2-mediated mRNA methylation increased the levels of ROS, activated p38MAPK, thereby accelerating oxidative stress- and high-glucose-induced senescence of human vascular endothelial cells (HUVEC). Our findings highlight the critical impact of NSUN2-mediated mRNA methylation in promoting premature senescence.

Self-assembled drug delivery system based on low-molecular-weight bis-amide organogelator: synthesis, properties and in vivo evaluation.

CONTEXT: Orgnaogels based on amino acid derivatives have been widely used in the area of drug delivery. OBJECTIVE: An organogel system based on l-lysine derivatives was designed and prepared to induce a thermal sensitive implant with higher transition temperature, better mechanical strength, and shorter gelation time. MATERIALS AND METHODS: The organogel was prepared by injectable soybean oil and methyl (S)-2,5-ditetradecanamidopentanoate (MDP), which was synthesized for the first time. Candesartan cilexetil (CC) was chosen as model drug. Different formulations were designed and optimized by response surface method. Thermal, rheology properties, and gelation kinetics of the optimized formulation had been characterized. The release behaviors in vitro, as well as in vivo were evaluated in comparison with the oily solution of drugs. Finally, the local inflammation response of in situ organogel was assessed by histological analysis. RESULTS AND DISCUSSION: Results showed that the synthesized gelator, MDP, had a good gelation ability and the organogels obtained via the self-assembly of gelators in vegetable oils exhibited great thermal and rheology properties, which guaranteed their state in body. In vivo pharmacokinetic demonstrated that the organogel formulation could extend the drug release and maintain a therapeutically effective plasma concentration at least 10 d. In addition, this implant showed acceptable moderate inflammation. CONCLUSION: The in situ forming l-lysine-derivative-based organogel could be a promising matrix for sustained drug delivery of the drugs with low solubility.

[The swelling behavior of choline fenofibrate hydrogel matrix tablets using dynamic image analysis].

The purpose of this study is to investigate the effects of formulation on the swelling behavior of choline fenofibrate hydrogel matrix tablets and reveal the relation between swelling property and release profile using dynamic image analysis. The volume swelling ratio (SR) and height/width (k) could evaluate the swelling behavior of matrix tablets well. The mount of hydroxypropyl methylcellulose (HPMC) and the ratio between K15M and K4M affected the volume swelling ratio, while PVP didn't. The three factors all impacted k, which was an indicator of the strength of the gel formed by HPMC. The accumulative release ratio and SR, the rate of swelling and the rate of release were compared. The proper model equations were established for the results with an excellent correlation. The results prove that there is a strong relevance between the swelling behavior and release property. This study provides a guideline in the study design for hydrogel matrix tablets.

NSun2 delays replicative senescence by repressing p27 (KIP1) translation and elevating CDK1 translation.

A rise in the levels of the cyclin-dependent kinase (CDK) inhibitor p27KIP1 is important for the growth arrest of senescent cells, but the mechanisms responsible for this increase are poorly understood. Here, we show that the tRNA methyltransferase NSun2 represses the expression of p27 in replicative senescence. NSun2 methylated the 5'-untranslated region (UTR) of p27 mRNA at cytosine C64 in vitro and in cells, thereby repressing the translation of p27. During replicative senescence, increased p27 protein levels were accompanied by decreased NSun2 protein levels. Knockdown of NSun2 in human diploid fibroblasts (HDFs) elevated p27 levels and reduced the expression of CDK1 (encoded by CDK1 mRNA, a previously reported target of NSun2), which in turn further repressed cell proliferation and accelerated replicative senescence, while overexpression of NSun2 exerted the opposite effect. Ectopic overexpression of the p27 5'UTR fragment rescued the effect of NSun2 overexpression in lowering p27, increasing CDK1, promoting cell proliferation, and delaying replicative senescence. Our findings indicate that NSun2-mediated mRNA methylation regulates p27 and CDK1 levels during replicative senescence.

NSun2 Promotes Cell Growth via Elevating Cyclin-Dependent Kinase 1 Translation.

The tRNA methytransferase NSun2 promotes cell proliferation, but the molecular mechanism has not been elucidated. Here, we report that NSun2 regulates cyclin-dependent kinase 1 (CDK1) expression in a cell cycle-dependent manner. Knockdown of NSun2 decreased the CDK1 protein level, while overexpression of NSun2 elevated it without altering CDK1 mRNA levels. Further studies revealed that NSun2 methylated CDK1 mRNA in vitro and in cells and that methylation by NSun2 enhanced CDK1 translation. Importantly, NSun2-mediated regulation of CDK1 expression had an impact on the cell division cycle. These results provide new insight into the regulation of CDK1 during the cell division cycle.

[The rheology properties of common hydrophilic gel excipients].

To investigate theological properties of common hydrophilic gel excipients such as Carbopol based on viscosity, the viscosity was determined by rotation method and falling-ball method. Linear regression was made between ln(eta) and concentration, the slope of which was used to explore the relation between viscosity and concentration of different excipients. The viscosity flow active energy (E(eta)) was calculated according to Arrhenius equation and was used to investigate the relation between viscosity and temperature of different excipients. The results showed that viscosities measured by two methods were consistent. Concentration of guargum (GG) and hydroxypropylmethyl cellulose (HPMC) solution had a great influence on the viscosity, k > 5; while concentration of polyvinylpyrrolidone-K30 (PVP-K30) and polyethylene glycol 6000 (PEG6000) exerted a less effect on viscosity, k < 0.2; viscosity flow active energy of different excipients were close, which ranged from 30 to 40 kJ x mol(-1). Therefore, theological properties study could provide the basis for application of excipients and establish a foundation for the research of relation between excipients structure, property and function.

A novel approach for secretion of heterologous proteins with correct n-terminal processing by using α-factor pre sequence in Pichia pastoris.

Numerous proteins have been secreted in P. pastoris by fusing the target gene with α-factor pre-pro sequence at Kex2 endopeptidase cleavage site. However, in some instances the product cannot be correctly processed due to aberrant cleavage by Kex2 endopeptidase such as aprotinin. In this study, an aprotinin gene was cloned into pPIC9K at the signal peptidase cleavage site through a single NheI restriction site designed at the 3'end of the α-factor signal sequence preregion, and transformed into GS115 host cell. By G418 resistance and ELISA assay, a high-yield recombinant was selected. After fed-batch cultivation in a 7-L bioreactor, the product was efficiently secreted into culture medium and accumulated up to ~4.7 mg L⁻¹. MALDI-TOF/MS and N-terminal analyses confirmed its authenticity. Thus, a novel cloning strategy for secretion of aprotinin with correct N-terminal processing in P. pastoris has been developed which can be potentially applied to other proteins.

The tRNA methyltransferase NSun2 stabilizes p16INK4 mRNA by methylating the 3'-untranslated region of p16.

The impact of methylation of the 3'-untranslated region (UTR) of a messenger RNA (mRNA) remains largely unknown. Here we show that NSun2, a transfer RNA methyltransferase, inhibits the turnover of p16(INK4) mRNA. Knockdown of NSun2 reduces p16 expression by shortening the half-life of the p16 mRNA, while overexpression of NSun2 stabilizes the p16 mRNA. In vitro methylation assays show that NSun2 methylates the p16 3'UTR at A988. Knockdown of NSun2 reduces the stability of the EGFP-p16 chimeric reporter transcripts bearing wild-type p16 3'UTR, but not p16 3'UTR with a mutant methylation site. Methylation by NSun2 prevents the association of p16 3'UTR with HuR, AUF1 and Ago2/RISC, and prevents the recruitment of EGFP-p16 3'UTR chimeric transcripts to processing bodies. In response to oxidative stress, NSun2 is essential for elevating p16 expression levels. We conclude that NSun2-mediated methylation of the p16 3'UTR is a novel mechanism to stabilize p16 mRNA.

Loss of repression of HuR translation by miR-16 may be responsible for the elevation of HuR in human breast carcinoma.

Elevated levels of RNA binding protein HuR were found in various human cancers. However, the mechanisms underlying HuR over-expression in cancers have not been fully elucidated. Here, we show that miR-16 acts as a novel post-transcriptional regulator for HuR. Knockdown of miR-16 increased HuR protein levels in MDA-MB-231 cells, while over-expression of pre-miR16 reduced HuR expression. Neither knockdown nor over-expression of miR-16 could alter the mRNA levels of HuR. Instead, knockdown of miR-16 increased the level of de novo synthesized HuR protein. Importantly, mechanistic studies showed that miR-16 associated with the 3'UTR of HuR, and knockdown of miR-16 markedly increased the luciferase activity of a HuR 3'UTR-containing reporter. We further demonstrate that the level of miR-16 was inversely correlated with HuR protein level in human breast carcinoma. Together, our results suggest an important role of miR-16 in regulating HuR translation and link this regulatory pathway to human breast cancer.