Development of novel robust nanobiocatalyst for detergents formulations and the other applications of alkaline protease

Alkaline protease from alkaliphilic Bacillus sp. NPST-AK15 was immobilized onto functionalized and non-functionalized rattle-type magnetic core@mesoporous shell silica (RT-MCMSS) nanoparticles by physical adsorption and covalent attachment. However, the covalent attachment approach was superior for NPST-AK15 protease immobilization onto the activated RT-MCMSS-NH₂ nanoparticles and was used for further studies. In comparison to free protease, the immobilized enzyme exhibited a shift in the optimal temperature and pH from 60 to 65 °C and pH 10.5–11.0, respectively. While free protease was completely inactivated after treatment for 1 h at 60 °C, the immobilized enzyme maintained 66.5 % of its initial activity at similar conditions. The immobilized protease showed higher k _cat and K _m , than the soluble enzyme by about 1.3-, and 1.2-fold, respectively. In addition, the results revealed significant improvement of NPST-AK15 protease stability in variety of organic solvents, surfactants, and commercial laundry detergents, upon immobilization onto activated RT-MCMSS-NH₂ nanoparticles. Importantly, the immobilized protease maintained significant catalytic efficiency for ten consecutive reaction cycles, and was separated easily from the reaction mixture using an external magnetic field. To the best of our knowledge this is the first report about protease immobilization onto rattle-type magnetic core@mesoporous shell silica nanoparticles that also defied activity-stability tradeoff. The results clearly suggest that the developed immobilized enzyme system is a promising nanobiocatalyst for various bioprocess applications requiring a protease.     

Effect of Medicago sativa L. and compost on organic and inorganic pollutant removal from a mixed contaminated soil and risk assessment using ecotoxicological tests

Several Gentle Remediation Options (GRO), e.g., plant-based options (phytoremediation), singly and combined with soil amendments, can be simultaneously efficient for degrading organic pollutants and either stabilizing or extracting trace elements (TEs). Here, a 5-month greenhouse trial was performed to test the efficiency of Medicago sativa L., singly and combined with a compost addition (30% w/w), to treat soils contaminated by petroleum hydrocarbons (PHC), Co and Pb collected at an auto scrap yard. After 5 months, total soil Pb significantly decreased in the compost-amended soil planted with M. sativa, but not total soil Co. Compost incorporation into the soil promoted PHC degradation, M. sativa growth and survival, and shoot Pb concentrations [3.8 mg kg^?1 dry weight (DW)]. Residual risk assessment after the phytoremediation trial showed a positive effect of compost amendment on plant growth and earthworm development. The O₂ uptake by soil microorganisms was lower in the compost-amended soil, suggesting a decrease in microbial activity. This study underlined the benefits of the phytoremediation option based on M. sativa cultivation and compost amendment for remediating PHC- and Pb-contaminated soils.     

Design of an Inflammation-Sensitive Polyelectrolyte-Based Topical Drug Delivery System for Arthritis

The most successful treatment strategy for arthritis is intra-articular injections that are costly and have reduced patient compliance. The purpose of the current study was to develop an inflammation-sensitive system for topical drug administration. Multi-macromolecular alginate-hyaluronic acid-chitosan (A-H-C) polyelectrolyte complex nanoparticles, loaded with indomethacin were developed employing pre-gel and post-gel techniques in the presence of dodecyl-l-pyroglutamate (DLP). In addition to in vitro studies, in silico simulations were performed to affirm and associate the molecular interactions inherent to the formulation of core all-natural multi-component biopolymeric architectures composed of an anionic (alginate), a cationic (chitosan), and an amphi-ionic polyelectrolytic (hyaluronic acid) macromolecule. The results demonstrated that DLP significantly influenced the size of the synthesized nanoparticles. Drug-content analysis revealed higher encapsulation efficiency (77.3%) in the presence of DLP, irrespective of the techniques used. Moreover, in vitro drug release studies showed that indomethacin release from the nanosystem was significantly improved (98%) in Fenton’s reagent. Drug permeation across a cellulose membrane using a Franz diffusion cell system showed an initial surge flux (0.125 mg/cm^?2/h), followed by sustained release of indomethacin for the post-gel nanoparticles revealing its effective skin permeation efficiency. In conclusion, the study presents novel nanoparticles which could effectively encapsulate and deliver hydrophobic drugs to the target site, particularly for arthritis.     

New Combretastatin Analogs as Anticancer Agents: Design,Synthesis, Microtubules Polymerization Inhibition,and Molecular Docking Studies

A new series of 4-(4-methoxyphenyl)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole-3-thiol derivatives were synthesized as analogs for the anticancer drug combretastatin A-4 ( CA-4 ) and characterized using FT-IR, ¹H-NMR, ¹³CNMR, and HR-MS techniques. The new CA-4 analogs were designed to meet the structural requirements of the highest expected anticancer activity of CA-4 analogs by maintaining ring A 3,4,5-trimethoxyphenyl moiety, and at the same time varying the substituents effect of the triazole moiety (ring B ). In silico analysis indicated that compound 3 has higher total energy and dipole moment than colchicine and the other analogs, and it has excellent distribution of electron density and is more stable, resulting in an increased binding affinity during tubulin inhibition. Additionally, compound 3 was found to interact with three apoptotic markers, namely p53, Bcl-2, and caspase 3. Compound 3 showed strong similarity to colchicine , and it has excellent pharmacokinetics properties and a good dynamic profile. The in vitro anti-proliferation studies showed that compound 3 is the most cytotoxic CA-4 analog against cancer cells (IC₅₀ of 6.35 μM against Hep G2 hepatocarcinoma cells), and based on its selectivity index (4.7), compound 3 is a cancer cytotoxic-selective agent. As expected and similar to colchicine , compound 3 -treated Hep G2 hepatocarcinoma cells were arrested at the G2/M phase resulting in induction of apoptosis. Compound 3 tubulin polymerization IC₅₀ (9.50 μM) and effect on V_max of tubulin polymerization was comparable to that of colchicine (5.49 μM). Taken together, the findings of the current study suggest that compound 3 , through its binding to the colchicine-binding site at β-tubulin, is a promising microtubule-disrupting agent with excellent potential to be used as cancer therapeutic agent.     

Dentin regeneration based on tooth tissue engineering: A review

Missing or damaged teeth due to caries, genetic disorders, oral cancer, or infection may contribute to physical and mental impairment that reduces the quality of life. Despite major progress in dental tissue repair and those replacing missing teeth with prostheses, clinical treatments are not yet entirely satisfactory, as they do not regenerate tissues with natural teeth features. Therefore, much of the focus has centered on tissue engineering (TE) based on dental stem/progenitor cells to create bioengineered dental tissues. Many in vitro and in vivo studies have shown the use of cells in regenerating sections of a tooth or a whole tooth. Tooth tissue engineering (TTE), as a promising method for dental tissue regeneration, can form durable biological substitutes for soft and mineralized dental tissues. The cell-based TE approach, which directly seeds cells and bioactive components onto the biodegradable scaffolds, is currently the most potential method. Three essential components of this strategy are cells, scaffolds, and growth factors (GFs). This study investigates dentin regeneration after an injury such as caries using TE and stem/progenitor cell-based strategies. We begin by discussing about the biological structure of a dentin and dentinogenesis. The engineering of teeth requires knowledge of the processes that underlie the growth of an organ or tissue. Then, the three fundamental requirements for dentin regeneration, namely cell sources, GFs, and scaffolds are covered in the current study, which may ultimately lead to new insights in this field.     

Synthesis,antimicrobial activity and acid dissociation constants of methyl 5,5-diphenyl-1-(thiazol-2-yl)pyrrolidine-2-carboxylate derivatives

In this study, a series of polysubstituted methyl 5,5-diphenyl-1-(thiazol-2-yl)pyrrolidine-2-carboxylate derivatives were designed and synthesized by the cyclization reaction of methyl 1-(benzoylcarbamothioyl)-5,5-diphenylpyrrolidine-2-carboxylates and 2-bromo-1-(4-substituted phenyl)ethanones in 70–96% yield. The starting pyrrolidine derivatives were synthesized via a 1,3-dipolar cycloaddition reaction in 83–88% yield. The stereochemistry of one of these methyl 5,5-diphenyl-1-(thiazol-2-yl)pyrrolidine-2-carboxylate derivatives was characterized by a single crystal X-ray diffraction study and the acid dissociation constants of these compounds were determined. An antimicrobial screening was performed against different bacterial and fungal strains and against the M. tuberculosis H37Rv strain. Interesting antibacterial activity was observed for two compounds against the A. baumannii strain with MIC values of 31.25?µg/mL (Ampicillin: 125?µg/mL) and against the M. tuberculosis H37Rv strain with MIC values of 0.98–1.96?µg/mL (Isoniazid: 0.98?µg/mL, Ethambutol: 1.96?µg/mL). Therefore, these structures can be considered as good starting points for the development of new powerful antimycobacterial agents.     

16S rRNA metagenomic analysis of the symbiotic community structures of bacteria in foregut,midgut, and hindgut of the wood-feeding termite <Emphasis Type="Italic">Bulbitermes</Emphasis> sp.

The termite gut is a highly structured microhabitat with physicochemically distinct regions. It is generally separated into the foregut, midgut and hindgut. The distribution of gut microbiota is greatly influenced by varying physicochemical conditions within the gut. Thus, each gut compartment has a unique microbial population structure. In this study, the bacterial communities of foregut, midgut and hindgut of wood-feeding higher termite, Bulbitermes sp. were analyzed in detail via metagenomic sequencing of the 16S rRNA V3-V4 region. While the microbiomes of the foregut and midgut shared a similar taxonomic pattern, the hindgut possessed more diverse bacterial phylotypes. The communities in the foregut and midgut were dominated by members of the group Bacilli and Clostridia (Firmicutes) as well as taxon Actinomycetales (Actinobacteria). The main bacterial lineage found in hindgut was Spirochaetaceae (Spirochaetes). The significant difference among the three guts was the relative abundance of the potential lignin-degrading bacteria, Actinomycetales, in both the foregut and midgut. This suggests that lignin modification was probably held in the anterior part of termite gut. Predictive functional profiles of the metagenomes using 16S rRNA marker gene showed that cell motility, energy metabolism and metabolism of cofactors and vitamins were found predominantly in hindgut microbiota, whereas xenobiotics degradation and metabolism mostly occurred in the foregut segment. This was compatible with our 16S rRNA metagenomic results showing that the lignocellulose degradation process was initiated by lignin disruption, increasing the accessibility of celluloses and hemicelluloses.     

Protective effects of resveratrol on hepatic ischemia reperfusion injury in streptozotocin-induced diabetic rats

Molecular and Cellular Biochemistry - Resveratrol (RSV) is a natural polyphenolic compound having antioxidant effects. This study was designed to investigate the protective effects of resveratrol...     

Kinetic evidence supports the existence of two halide binding sites that have a distinct impact on the heme iron microenvironment in myeloperoxidase

Myeloperoxidase (MPO) structural analysis has suggested that halides and pseudohalides bind to the distal binding site and serve as substrates or inhibitors, while others have concluded that there are two separate sites. Here, evidence for two distinct binding sites for halides comes from the bell-shaped effects observed when the second-order rate constant of nitric oxide (NO) binding to MPO was plotted versus Cl- concentration. The chloride level used in the X-ray structure that produced Cl- binding to the amino terminus of the helix halide binding site was insufficient to populate either of the two sites that appear to be responsible for the two phases. Biphasic effects were also observed when the I-, Br-, and SCN- concentrations were plotted against the NO combination rate constants. Interestingly, the trough concentrations obtained from the bell-shaped curves are comparable to normal plasma levels of halides and pseudohalides, suggesting the potential relevance of these molecules in modulating MPO function. The second-order rate constant of NO binding in the presence of plasma levels of I-, Br-, and SCN- is 1-2-fold lower compared to that obtained in the absence of these molecules and remains unaltered through the Cl- plasma level. When Cl- exceeded the plasma level, the NO combination rate becomes indistinguishable from the second phase of the bell-shaped curve that was obtained in the absence of halides. Our results are consistent with two halide binding sites that could be populated by two halides in which both display distinct effects on the MPO heme iron microenvironment.     

Metastatic ganglioneuroblastoma in head and neck diagnosed by fine needle aspiration: a case report

BACKGROUND: To describe the cytologic findings of a case of ganglioneuroblastoma metastatic to the jaw and neck. CASE: A 15-year-old boy with a known case of ganglioneuroblastoma of the kidney for the previous 10 years manifested by right mandibular and neck masses on 2 occasions 1 year apart was diagnosed with metastatic ganglioneuroblastoma by fine needle aspiration (FNA). FNA showed neurofibrillary material, small malignant cells, Homer-Wright rosettes. mononucleated, binucleated and multinucleated ganglion cells and Reed Sternberg-like ganglion cells. Metastatic ganglioneuroblastoma was diagnosed on both occasions, and the patient received appropriate treatment, with resolution of the lesions. CONCLUSION: This case illustrates the FNA findings of metastatic ganglioneuroblastoma in the head and neck region.