Preparation and evaluation of peptide-dendrimer-paclitaxel conjugates for treatment of heterogeneous stage 1 nonsmall cell lung cancer in 293T and L132 cell lines

Purpose: To develop peptide-dendrimer-paclitaxel conjugates for the treatment of heterogeneous stage 1 non small cell lung cancer (NSCLC) in 293T and L132cell line.Method: Dendrimer-paclitaxel conjugates (PAMAM-PTX) were prepared by NHS method and the conjugates were used for the synthesis of peptide-dendrimer-paclitaxel conjugates (GE-PAMAM-PTX). The particle sizes of PAMAM-PTX and GE-PAMAM-PTX were measured. Entrapment efficiency of PTX in PAMAM-PTX was measured while GE-PAMAM-PTX. PTX release from PAMAM-PTX and GEPAMAM- PTX was determined using a dialysis bag in pH 7.4 phosphate buffer. The cytotoxicity of PAMAM-PTX, GE-PAMAM-PTX, PAMAM and PTX was evaluated by 3-(4,5-dimethylthiazol-2-Yl)-2,5- diphenyltetrazolium bromide (MTT) assay using 293T cell lines. In vitro cellular uptake assay of PAMAM-PTX and GE-PAMAM-PTX and PTX at concentrations ranging from 0.01 to 0.5μM for 8 h was carried out in NSCLC cell lines 293T and L132.Results: More than 95 % entrapment efficiency of GE-PAMAM-PTX was observed with loading efficiency of 25 %. GE-PAMAM-PTX conjugates showed sustained release of PTX (~85 %) towards the end of 50 h. GE-PAMAM-PTX conjugates were more cytotoxic than pure PTX and PAMAM-PTX conjugates. The remarkable uptake of GE-PAMAM-PTX appear to be due to receptor-mediated endocytosis in the cell lines. The presence of ligand (GE) on PAMAM-PTX surface enabled the complex to bind to the over-expressed receptors on the cell lines.Conclusion: GE-PAMAM-PTX can facilitate targeting of paclitaxel to lung cancer cell lines and tumors and facilitate release of the drugs in a sustained manner to improve the therapeutic efficacy of PTX.Keywords: Paclitaxel, Lung cancer, Non-small cell lung cancer, Dendrimer, Peptide, PAMA

Development of Polysorbate 80/Phospholipid mixed micellar formation for docetaxel and assessment of its in vivo distribution in animal models

Docetaxel (DTX) is a very important member of taxoid family. Despite several alternative delivery systems reported recently, DTX formulated by Polysorbate 80 and alcohol (Taxotere®) is still the most frequent administration in clinical practice. In this study, we incorporated DTX into Polysorbate 80/Phospholipid mixed micelles and compared its structural characteristics, pharmacokinetics, biodistribution, and blood compatibility with its conventional counterparts. Results showed that the mixed micelles loaded DTX possessed a mean size of approximately 13 nm with narrow size distribution and a rod-like micelle shape. In the pharmacokinetics assessment, there was no significant difference between the two preparations (P > 0.05), which demonstrated that the DTX in the two preparations may share a similar pharmacokinetic process. However, the Polysorbate 80/Phospholipid mixed micelles can increase the drug residence amount of DTX in kidney, spleen, ovary and uterus, heart, and liver. The blood compatibility assessment study revealed that the mixed micelles were safe for intravenous injection. In conclusion, Polysorbate 80/Phospholipid mixed micelle is safe, can improve the tumor therapeutic effects of DTX in the chosen organs, and may be a potential alternative dosage form for clinical intravenous administration of DTX

Draft Genome Sequence of Methylocella silvestris TVC, a Facultative Methanotroph Isolated from Permafrost

Permafrost environments play a crucial role in global carbon and methane cycling. We report here the draft genome sequence of Methylocella silvestris TVC, a new facultative methanotroph strain, isolated from the Siksik Creek catchment in the continuous permafrost zone of Inuvik (Northwest Territories, Canada)

Phosphorylation of Synaptojanin Differentially Regulates Endocytosis of Functionally Distinct Synaptic Vesicle Pools

The rapid replenishment of synaptic vesicles through endocytosis is crucial for sustaining synaptic transmission during intense neuronal activity. Synaptojanin (Synj), a phosphoinositide phosphatase, is known to play an important role in vesicle recycling by promoting the uncoating of clathrin following synaptic vesicle uptake. Synj has been shown to be a substrate of the minibrain (Mnb) kinase, a fly homolog of the dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A); however, the functional impacts of Synj phosphorylation by Mnb are not well understood. Here we identify that Mnb phosphorylates Synj at S1029 in Drosophila. We find that phosphorylation of Synj at S1029 enhances Synj phosphatase activity, alters interaction between Synj and endophilin, and promotes efficient endocytosis of the active cycling vesicle pool (also referred to as exo-endo cycling pool) at the expense of reserve pool vesicle endocytosis. Dephosphorylated Synj, on the other hand, is deficient in the endocytosis of the active recycling pool vesicles but maintains reserve pool vesicle endocytosis to restore total vesicle pool size and sustain synaptic transmission. Together, our findings reveal a novel role for Synj in modulating reserve pool vesicle endocytosis and further indicate that dynamic phosphorylation and dephosphorylation of Synj differentially maintain endocytosis of distinct functional synaptic vesicle pools. SIGNIFICANCE STATEMENT Synaptic vesicle endocytosis sustains communication between neurons during a wide range of neuronal activities by recycling used vesicle membrane and protein components. Here we identify that Synaptojanin, a protein with a known role in synaptic vesicle endocytosis, is phosphorylated at S1029 in vivo by the Minibrain kinase. We further demonstrate that the phosphorylation status of Synaptojanin at S1029 differentially regulates its participation in the recycling of distinct synaptic vesicle pools. Our results reveal a new role for Synaptojanin in maintaining synaptic vesicle pool size and in reserve vesicle endocytosis. As Synaptojanin and Minibrain perturbations are associated with various neurological disorders, such as Parkinson's, autism, and Down syndrome, understanding mechanisms modulating Synaptojanin function provides valuable insights into processes affecting neuronal communication

Mesoporous LaMnO3+delta perovskite from spray - pyrolysis with superior performance for oxygen reduction reaction and Zn - air battery

Oxygen reduction reaction (ORR) is the key reaction in various electrochemical energy devices. This work reports an inexpensive mesoporous LaMnO3+δ perovskite for ORR with remarkable activity, synthesized by a facile aerosol-spray assisted approach. The mesoporous LaMnO3+δ material shows a factor of 3.1 higher activity (at 0.9 V vs. RHE) than LaMnO3 obtained from co-precipitation method (LMO-CP). Based on results of x-ray absorption near-edge spectroscopy (XANES), x-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) analysis, we conclude that the chemical state of surface Mn and the high surface area are the sources to the notably enhanced activity. The study of Zn-air batteries device further confirmed a Pt/C comparable performance in the practical devices with the novel mesoporous LaMnO3+δ catalyst, where the power density at 200 mA/cm2 is only 2.1% lower than in the battery with same-loaded Pt/C catalyst. Therefore, the high mass activity and low-cost of Mn/La may make LaMnO3+δ further approach to the application of electrochemical devices.Peer reviewe

Assessing Matched Normal and Tumor Pairs in Next-Generation Sequencing Studies

Next generation sequencing technology has revolutionized the study of cancers. Through matched normal-tumor pairs, it is now possible to identify genome-wide germline and somatic mutations. The generation and analysis of the data requires rigorous quality checks and filtering, and the current analytical pipeline is constantly undergoing improvements. We noted however that in analyzing matched pairs, there is an implicit assumption that the sequenced data are matched, without any quality check such as those implemented in association studies. There are serious implications in this assumption as identification of germline and rare somatic variants depend on the normal sample being the matched pair. Using a genetics concept on measuring relatedness between individuals, we demonstrate that the matchedness of tumor pairs can be quantified and should be included as part of a quality protocol in analysis of sequenced data. Despite the mutation changes in cancer samples, matched tumor-normal pairs are still relatively similar in sequence compared to non-matched pairs. We demonstrate that the approach can be used to assess the mutation landscape between individuals