Andrographolide Induces G2/M Cell Cycle Arrest and Apoptosis in Human Glioblastoma DBTRG-05MG Cell Line via ERK1/2 /c-Myc/p53 Signaling Pathway

Human glioblastoma multiforme (GBM) is one of the most malignant brain tumors, with a high mortality rate worldwide. Conventional GBM treatment is now challenged by the presence of the blood–brain barrier (BBB), drug resistance, and post-treatment adverse effects. Hence, developing bioactive compounds isolated from plant species and identifying molecular pathways in facilitating effective treatment has become crucial in GBM. Based on pharmacodynamic studies, andrographolide has sparked the interest of cancer researchers, who believe it may alleviate difficulties in GBM therapy; however, it still requires further study. Andrographolide is a bicyclic diterpene lactone derived from Andrographis paniculata (Burm.f.) Wallich ex Nees that has anticancer properties in various cancer cell lines. The present study aimed to evaluate andrographolide’s anticancer effectiveness and potential molecular pathways using a DBTRG-05MG cell line. The antiproliferative activity of andrographolide was determined using the WST-1 assay, while scratch assay and clonogenic assay were used to evaluate andrographolide’s effectiveness against the cancer cell line by examining cell migration and colony formation. Flowcytometry was also used to examine the apoptosis and cell cycle arrest induced by andrographolide. The mRNA and protein expression level involved in the ERK1/2/c-Myc/p53 signaling pathway was then assessed using qRT-PCR and Western blot. The protein–protein interaction between c-Myc and p53 was determined by a reciprocal experiment of the co-immunoprecipitation (co-IP) using DBTRG-05MG total cell lysate. Andrographolide significantly reduced the viability of DBTRG-05MG cell lines in a concentration- and time-dependent manner. In addition, scratch and clonogenic assays confirmed the effectiveness of andrographolide in reducing cell migration and colony formation of DBTRG-05MG, respectively. Andrographolide also promoted cell cycle arrest in the G2/M phase, followed by apoptosis in the DBTRG-05MG cell line, by inducing ERK1/2, c-Myc, and p53 expression at the mRNA level. Western blot results demonstrated that c-Myc overexpression also increased the production of the anti-apoptotic protein p53. Our findings revealed that c-Myc and p53 positively interact in triggering the apoptotic signaling pathway. This study successfully discovered the involvement of ERK1/2/c-Myc/p53 in the suppression of the DBTRG-05MG cell line via cell cycle arrest followed by the apoptosis signaling pathway following andrographolide treatment.     

Characterization of parasitic residual deposition on passivation layer in electroless nickel immersion gold process

The problem of parasitic residual deposition on the passivation layer in electroless deposition process is studied in this paper. The characterization analysis tools involved are focused ion beam (FIB), scanning electron microscopy (SEM), electron dispersive X-ray (EDX) and metallurgical interface analysis. Samples were identified as either good or bad prior to the characterization process via a high power microscope. A good sample is the one without parasitic deposition while a bad sample contains parasitic residual deposition on the passivation surface. Ultrasonic vibration has been able to remove the parasitic deposition and reveal crack presence on the passivation surfaces. Crack was found extended to the aluminum underneath that leads to the formation of the parasitic residual deposition. Additional sacrificial photoresist on top of passivation was able to eliminate this parasitic deposition.     

Mechanical and Morphological Properties of Bio-Phenolic/Epoxy Polymer Blends

Polymer blends is a well-established and suitable method to produced new polymeric materials as compared to synthesis of a new polymer. The combination of two different types of polymers will produce a new and unique material, which has the attribute of both polymers. The aim of this work is to analyze mechanical and morphological properties of bio-phenolic/epoxy polymer blends to find the best formulation for future study. Bio-phenolic/epoxy polymer blends were fabricated using the hand lay-up method at different loading of bio-phenolic (5 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt%) in the epoxy matrix whereas neat bio-phenolic and epoxy samples were also fabricated for comparison. Results indicated that mechanical properties were improved for bio-phenolic/epoxy polymer blends compared to neat epoxy and phenolic. In addition, there is no sign of phase separation in polymer blends. The highest tensile, flexural, and impact strength was shown by P-20(biophenolic-20 wt% and Epoxy-80 wt%) whereas P-25 (biophenolic-25 wt% and Epoxy-75 wt%) has the highest tensile and flexural modulus. Based on the finding, it is concluded that P-20 shows better overall mechanical properties among the polymer blends. Based on this finding, the bio-phenolic/epoxy blend with 20 wt% will be used for further study on flax-reinforced bio-phenolic/epoxy polymer blends.     

One-Step Synthesis of Stable Colloidal Gold Nanoparticles Through Bioconjugation with Bovine Serum Albumin in Harsh Environments

In saline solutions with NaCl concentrations less than that typical of blood plasma and bodily fluids, gold nanoparticles (GNPs) aggregate and precipitate because of GNP cation complexation with the Cl^? anions in the solution. It is difficult to retain stable colloidal GNPs within any saline solution for a relatively long time without aggregation and precipitation. In this study, we developed a method to synthesize stable GNPs in harsh anion-containing environments. GNPs were formed by laser ablation in a saline solution, and their stabilization was achieved by adding bovine serum albumin (BSA) to the NaCl solution; this has been shown to be a quick, efficient approach to producing stable colloidal GNPs. GNP nanoclusters in saline solutions with and without BSA were observed via high-resolution transmission electron microscopy and selected area electron diffraction. The results reveal that our methodology yields colloidal GNPs with long-term stability in a BSA-containing saline solution.     

Mercury-bridged,nitrosyl substituted,triruthenium carbonyl clusters: Synthesis and x-ray crystal structure of [Ru3(NO)(CO)10]2Hg

The neutral mixed-metal cluster [Ru₃(NO)(CO)₁₀]₂Hg has been prepared by the reaction of the [Ru₃(NO)(CO)₁₀], with HgCl₂. An X-ray crystal structure shows that the mercury atom links two Ru₃ triangular units by bridging an RuRu edge of each unit. The dihedral angle between the two Ru₂Hg triangles is 27.6°. In each Ru₃ triangle a nitrosyl ligand bridges the same RuRu edge as the bridging Hg atom while the ten carbonyl groups are all terminal.     

Maleic Anhydride Polyethylene Octene Elastomer Toughened Polyamide 6/Polypropylene Nanocomposites: Mechanical and Morphological Properties

A series of polyamide 6/polypropylene (PA6/PP) blends and nanocomposites containing 4 wt% of organophilic modified montmorillonite (MMT) were designed and prepared by melt compounding followed by injection molding. Maleic anhydride polyethylene octene elastomer (POEgMAH) was used as impact modifier as well as compatibilizer in the blend system. Three weight ratios of PA6/PP blends were prepared i.e. 80:20, 70:30, and 60:40. The mechanical properties of PA6/PP blends and nanocomposite were studied through flexural and impact properties. Scanning electron microscopy (SEM) was used to study the microstructure. The incorporation of 10 wt% POEgMAH into PA6/PP blends significantly increased the toughness with a corresponding reduction in strength and stiffness. However, on further addition of 4 wt% organoclay, the strength and modulus increased but with a sacrifice in impact strength. It was also found that the mechanical properties are a function of blend ratio with 70:30 PA6/PP having the highest impact strength, both for blends and nanocomposites. The morphological study revealed that within the blend ratio studied, the higher the PA6 content, the finer were the POEgMAH particles.