Synergistic antibacterial effect of the pistachio green hull extract-loaded porphysome decorated with 4-nitroimidazole against bacteria.

'Active targeting' refers to modifying a nanocarrier's surface with targeting ligands. This study introduced an efficient approach for immobilizing imidazole-based drugs onto the metallated-porphyrin complex within the porphysome nanocarrier. To enhance cellular and bacterial uptake, a Ni-porphyrin with a fatty acid tail was synthesized and placed in the bilayer center of DPPC, facilitating receptor-mediated endocytosis. The Ni-porphyrin in the head group of the Ni-porphyrin-tail was placed superficially in the polar region of the membrane. Spherical unilamellar vesicle formation (DPPC: Ni-porphyrin-tail 4:1 mole ratio), as metallo-porphysome, was achieved through supramolecular self-assembly in an aqueous buffer. These vesicles exhibited a diameter of 279 ± 7 nm and a zeta potential of -15.3 ± 2.5 mV, showcasing their unique cytocompatibility. Nitroimidazole was decorated on the surface of metallo-porphysomes and pistachio green hull extract (PGHE) was loaded into the carrier for synergistic activity against (E. coli) and (S. aureus) bacteria strains. The physicochemical properties of Nitroimidazole-porphysome-PGHE, including size, zeta potential, morphology, loading efficiency, and release profile under various pH and temperature conditions in simulated gastrointestinal fluids were characterized. This combination therapy prevented bacterial cell attachment and biofilm formation in Caco-2 cells, as colon epithelial cells. The remarkable benefit of this system is that it does not affect cell viability even at 0.5 mg/ml. This study demonstrates the potential of a new co-delivery system using biocompatible metallo-porphysomes to decrease bacterial infections.

Alteration in the callogenesis, tropane alkaloid formation, and gene expression in Hyoscyamus niger under clinorotation.

This study aimed to investigate the effects of clinorotation induced by 2-D clinostat on the growth, tropane alkaloid production, gene expression, antioxidant capacity, and cellular defense responses in the callus tissue of Hyoscyamus niger. Callus induction was conducted by putting hypocotyl explants in the MS culture medium supplemented with 1 mgL-1 2,4-D and 1 mgL-1 BAP growth regulators. The sub-cultured calli were placed on a clinostat for 0, 3, 7, and 10 days (2.24 × 10-5 g on the edge of the callus ring). Clinorotation significantly increased callus fresh weight, dry weight, protein, carbohydrate, and proline contents compared to the control, and their maximum contents were obtained after 7 and 10 days. H2O2 level enhanced under clinorotation with a 76.3% rise after 10 days compared to control and positively affected the atropine (77.1%) and scopolamine (69.2%) productions. Hyoscyamine 6-beta hydroxylase and putrescine N-methyltransferase gene expression involved in the tropane alkaloid biosynthesis were upregulated markedly with 14.2 and 17.1-folds increase after 10 days of clinorotation, respectively. The expressions of jasmonic acid, mitogen-activated protein kinase, and ethylene-responsive element-binding transcription factor were upregulated, and the activity of peroxidase and catalase showed a 72.7 and 80% rise after 10 days. These findings suggest that microgravity can enhance callogenesis by stimulating the ROS level, which can impact the antioxidant enzymes, tropane alkaloid formation, and gene expression.

Grafting of sinapic acid onto glucosamine nanoparticle as a potential therapeutic drug with enhanced anti-inflammatory activities in osteoarthritis treatment.

Glucosamine (Glu) is a cartilage and joint fluid matrix precursor that modulates osteoarthritic joint changes. To improve the enzymatic stability, glucosamine was developed into nanoglucosamine by the ionic gelation method through sodium tripolyphosphate (TPP) as cross-linking agent. The optimized mass ratio of Glu:TPP was (3:1) with the particle size 163 ± 25 nm and surface charge -5 mV. Then Sinapic acid (SA) as a natural phenolic acid with strong antioxidant and antimicrobial activities has been grafted onto glucosamine nanoparticles (GluNPs) with grafting efficiency (73 ± 6 %). The covalent insertion of SA was confirmed by UV-Vis, FTIR, 1HNMR, XRD, and FESEM analyses and the other physicochemical properties were also characterized. SA-g-GluNPs showed spherical shape with a mean diameter of 255 ± 20 nm and zeta potential +16 mV. The in vitro release profile of SA-g-GluNPs exhibited the sustained and pH-dependent drug release property. SA-g-GluNPs had a more pronounced effect on reducing the elevated levels of LPS-induced oxidative stress and pro-inflammatory cytokines than free SA in the human chondrocyte C28/I2 cell line. Furthermore, the antibacterial properties against E. coli and S. aureus were also improved by SA-g-GluNPs. This study demonstrated the potential of phenolic acid grafted GluNPs in therapeutic drug applications for chondroprotection and food industries.

Chromone-embedded peptidomimetics and furopyrimidines as highly potent SARS-CoV-2 infection inhibitors: docking and MD simulation study.

BACKGROUND: COVID-19 is a respiratory illness caused by SARS-CoV-2. Pharmaceutical companies aim to control virus spread through effective drugs. This study investigates chromone compound derivatives' ability to inhibit viral entry and prevent replication. METHOD: This study investigated the inhibitory effect of chromone-embedded peptidomimetics and furopyrimidines on 7BZ5 from Severe Acute Respiratory Syndrome CoV-2, Homo sapiens, and 6LU7 from Bat SARS-like CoV using molecular docking. The crystal structure of these proteins was obtained from the Protein Data Bank, and the inhibition site was determined using ligand binding interaction options. The 3D structure was protonated and energetically minimised using MOE software. Chromone derivatives were designed in three dimensions, and their energy was minimised using MOE 2019. The molecular drug-likeness was calculated using SwissADME, Lipinski and Benigni-Bossa's rule, and toxicity was calculated using Toxtree v3.1.0 software. Compounds with pharmacological properties were selected for molecular docking, and interactions were assessed using MOE 2019. MD simulations of Mpro-ch-p complexes were performed to evaluate root mean square fluctuations (RMSF) and measure protein stability. RESULT: The pharmacokinetic tests revealed that chromone derivatives of the peptidomimetic family have acceptable pharmacokinetic activity in the human body. Some compounds, such as Ch-p1, Ch-p2, Ch-p6, Ch-p7, Ch-p12, and Ch-p13, have pronounced medicinal properties. Molecular docking revealed high affinity for binding to SARS-CoV-2 protease. Ch-p7 had the highest binding energy, likely due to its inhibitory property. A 10 ns molecular dynamics study confirmed the stability of the protein-ligand complex, resulting in minimal fluctuations in the system's backbone. The MM-GBSA analysis revealed free energies of binding of - 19.54 kcal/mol. CONCLUSIONS: The study investigated the inhibition of viral replication using chromone derivatives, finding high inhibitory effects in the peptidomimetic family compared to other studies.

Recent Advances in Nanomaterials of Group XIV Elements of Periodic Table in Breast Cancer Treatment.

Breast cancer is one of the most common malignancies and a leading cause of cancer-related mortality among women worldwide. The elements of group XIV in the periodic table exhibit a wide range of chemical manners. Recently, there have been remarkable developments in the field of nanobiomedical research, especially in the application of engineered nanomaterials in biomedical applications. In this review, we concentrate on the recent investigations on the antiproliferative effects of nanomaterials of the elements of group XIV in the periodic table on breast cancer cells. In this review, the data available on nanomaterials of group XIV for breast cancer treatment has been documented, providing a useful insight into tumor biology and nano-bio interactions to develop more effective nanotherapeutics for cancer patients.

Investigating Visfatin gene Polymorphism rs4730153 with Insulin Resistance and Non-Alcoholic Fatty Liver Diseases in Iranian Population.

Background: Visfatin is known as one of the adipokines associated with the development of inflammation, but its role in the pathogenesis of nonalcoholic fatty liver is less known so far. We aimed to investigate the association between visfatin gene polymorphism rs4730153 and insulin resistance and non-alcoholic fatty liver disease (NAFLD). Methods: This case-control study was performed on 80 patients with NAFLD as well as 80 healthy participants as controls referred to Amir Al-Momenin and Bouali hospitals in Tehran. Genotyping was performed using PCR-RFLP method. Plasma concentrations of visfatin and insulin were measured using ELISA kit. The fasting blood glucose, TC, TG, LDL-C, HDL-C, ALT, AST, SBP, DBP, and BMI levels were measured using the standard methods. Statistical analysis was also performed using SPSS software. Results: A significant difference was found in Visfatin level in the patients with NAFLD compared to this level in healthy individuals. The levels of HDL-C and LDL-C in healthy individuals and triglyceride in patients for GG, AG, and AA genotypes carriers also were significantly different. There was a significant relationship between rs4730153 polymorphism and insulin resistance; however, no association was found between this polymorphism and NAFLD. Notably, Visfatin showed a significant association with age (all individuals), body mass index (healthy individuals), insulin, and HOMA (in patients). Conclusion: Visfatin levels reduced in patients with NAFLD. Moreover, rs4730153 polymorphism was indicated to be associated with both lipid metabolism and insulin resistance, but no association was found between this polymorphism and nonalcoholic fatty liver disease.

Investigation of Signals and Transcription Factors for The Generation of Female Germ-Like Cells.

Objective: Primordial germ cell (PGCs) lines are a source of a highly specialized type of cells, characteristically oocytes,
during female germline development in vivo. The oocyte growth begins in the transition from the primary follicle. It is
associated with dynamic changes in gene expression, but the gene-regulating signals and transcription factors that control oocyte growth remain unknown. We aim to investigate the differentiation potential of mouse bone marrow mesenchymal stem cells (mMSCs) into female germ-like cells by testing several signals and transcription factors.
Materials and Methods: In this experimental study, mMSCs were extracted from mice femur bone using the flushing
technique. The cluster-differentiation (CD) of superficial mesenchymal markers was determined with flow cytometric analysis. We applied a set of transcription factors including retinoic acid (RA), titanium nanotubes (TNTs), and fibrin such as TNT-coated fibrin (F+TNT) formation and (RA+F+TNT) induction, and investigated the changes in gene, MVH/ DDX4, expression and functional screening using an in vitro mouse oocyte development condition. Germ cell markers expression, (MVH / DDX4), was analyzed with Immunocytochemistry staining, quantitative transcription-polymerase chain reaction (RT-qPCR) analysis, and Western blots.
Results: The expression of CD was confirmed by flow cytometry. The phase determination of the TNTs and F+TNT were confirmed using x-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. Remarkably, applying these transcription factors quickly induced pluripotent stem cells into oocyte-like cells that were sufficient to generate female germlike cells, growth, and maturation from mMSCs differentiation. These transcription factors formed oocyte-like cells specification of stem cells, epigenetic reprogramming, or meiosis and indicate that oocyte meiosis initiation and oocyte growth are not separable from the previous epigenetic reprogramming in stem cells in vitro.
Conclusion: Results suggested several transcription factors may apply for arranging oocyte-like cell growth and supplies an alternative source of in vitro maturation (IVM).

Structural and inhibitory effects of fulvic and humic acids against tyrosinase.

Inhibition of tyrosinase activity can control fruit browning and preserve the flavor and nutritional value of food. The impacts of fulvic acid (FA) and humic acid (HA) on tyrosinase activity were investigated utilizing circular dichroism (CD) and fluorescence spectroscopy, molecular docking (MD), and molecular dynamics simulations. HA and FA demonstrated a mixed type of inhibition with Ki 2.02 and 5.2 µM, respectively. The thermodynamic parameters displayed that the hydrogen bond and hydrophobic force play a major role in the FA-tyrosinase and HA-tyrosinase interaction, respectively. Fluorescence experiments demonstrated changes in tyrosinase tertiary structures. HA could not destroy the tyrosinase secondary structure significantly, however, FA has a significant influence on the tyrosinase secondary structure. The molecular dynamics findings demonstrated the minimal fluctuations and the lowest flexibility in the complex amino acids in the HA-tyrosinase and FA-tyrosinase interaction. Altogether, HA and FA could be utilized in food industries as an accessible natural source for tyrosinase inhibition. PRACTICAL APPLICATIONS: Recently, the investigation of tyrosinase inhibitors from the biosphere for hindrance of undesired browning in the food industry has increased considerably. Mushroom tyrosinase is a suitable model for kinetic research owing to its availability as well as close conformational similarity to tyrosinase in a mammal. Natural sources and their effective compounds could have wonderful potential on tyrosinase activity and structure, thus, in this study, the interactions between tyrosinase and fulvic acid (FA) and Humic acid (HA) were investigated. Previously, it has been shown that HA and FA have antioxidant properties and they can improve the quality of food via retarding lipid oxidation. Altogether, further investigations are warranted to draw firm conclusions, HA and FA could be utilized in food industries not only as antioxidant agents but also as an accessible natural source for tyrosinase inhibition.

Five-FU@CuS/NH2 -UiO-66 as a drug delivery system for 5-fluorouracil to colorectal cancer cells.

In this study, copper sulfide nanoparticles (CuS-NPs), which can improve the antiproliferative properties of conventional anticancer drugs such as 5-fluorouracil (5-FU), were incorporated into the pores of amine-functionalized UiO-66 (CuS/NH2 -UiO-66). The introduced nano-drug delivery system was exerted to perform an in vitro treatment on CT-26 mouse colorectal cancer cells. The synthesized final product was labeled as 5-FU@CuS/NH2 -UiO-66 and characterized through conventional methods including X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) analysis, Ultraviolet-Visible (UV-Vis) analysis, Inductively coupled plasma mass spectrometry (ICP-MS), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In contrast to 5-FU, the outcomes of the cytotoxicity assay lacked any comparable results for 5-FU@CuS/NH2 -UiO-66.

The Impacts of Prepared Plasma-Activated Medium (PAM) Combined with Doxorubicin on the Viability of MCF-7 Breast Cancer Cells: A New Cancer Treatment Strategy.

Background: For many years, the chemotherapeutic agent doxorubicin (DOX) has been used to treat various cancers; however, DOX initiates several critical adverse effects. Many studies have reported that non-thermal atmospheric pressure plasma can provide novel, but challenging, treatment strategies for cancer patients. To date, tissues and cells have been treated with plasma-activated medium (PAM) as a practical therapy. Consequently, due to the harmful adverse effects of DOX, we were motivated to elucidate the impact of PAM in the presence of DOX on MCF-7 cell proliferation. Methods: MTT assay, N-acetyl-L-cysteine (NAC) assay, and flow cytometry analysis were utilized in this research. Results: The results demonstrated that 0.45 µM DOX combined with 3-min PAM significantly induced apoptosis (p< 0.01) through intracellular ROS generation in MCF-7 when compared with 0.45 µM DOX alone or 3-min PAM alone. In contrast, after treatment with 0.45 µM DOX plus 4-min PAM, cell necrosis was increased. Hence, DOX combined with 4-min PAM has cytotoxic effects with different mechanisms than 4-min PAM alone, in which the number of apoptotic cells increases. Conclusion: Although further investigations are crucial, low doses of DOX plus 3-min PAM could be a promising strategy for cancer therapy. The findings from this research may offer advantageous and innovative clinical strategies for cancer therapy using PAM.

Sol-gel synthesis of amorphous calcium phosphate nanoparticles in brown rice substrate and assessment of their cytotoxicity and antimicrobial activities.

OBJECTIVE: This study intended to perform a synthesizing procedure for amorphous calcium phosphate (ACP) through a green template by the usage of brown rice (BR). MATERIALS AND METHODS: ACP nanoparticles were obtained by application of a sol-gel method and comprehensively characterized using X-ray powder diffraction (XRD), zeta potential, fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), and atomic force microscopy (AFM). Cytotoxic activity of ACP was evaluated in human epithelial type 2 (HEp-2) cell lines. The antibacterial effects of nanoparticles were appraised against Gram-positive Streptococcus mutans and Enterococcus faecalis. RESULTS: The procedures for the evaluation of the characterization outcomes, dispersion, and stability of our product were confirmed by observing the smooth and uniformed surfaces of ACP. The zeta potential value of the synthesized sample was -22 mV, which indicates its acceptable stable condition caused by electrostatic repulsion. The cytotoxicity of the ACP nanoparticles was investigated in HEp-2 cells, and results showed no cytotoxicity for the synthesized nanoparticles. Also, the obtained minimum inhibitory concentration (MIC) of ACP nanoparticles in opposition to S. mutans and E. faecalis was 15 and 20 µg/ml, respectively, indicating the resistance of E. faecalis in comparison to S. mutans and MBC for synthesized nanoparticles against S. mutans and E. faecalis strains was 20 and 25 µg/ml. CONCLUSION: The present study showed that this compound has no toxicity on the examined cell line. Also, the antibacterial properties of the synthesized ACP were approved by the obtained data, which enables the application of this material for therapeutic purposes in the pharmaceutical industry.

Metal removal capability of two cyanobacterial species in autotrophic and mixotrophic mode of nutrition.

BACKGROUND: Cyanobacteria are ecologically significant prokaryotes that can be found in heavy metals contaminated environments. As their photosynthetic machinery imposes high demands for metals, homeostasis of these micronutrients has been extensively considered in cyanobacteria. Recently, most studies have been focused on different habitats using microalgae leads to a remarkable reduction of an array of organic and inorganic nutrients, but what takes place in the extracellular environment when cells are exposed to external supplementation with heavy metals remains largely unknown. METHODS: Here, extracellular polymeric substances (EPS) production in strains Nostoc sp. N27P72 and Nostoc sp. FB71 was isolated from different habitats and thenthe results were compared and reported. RESULT: Cultures of both strains, supplemented separately with either glucose, sucrose, lactose, or maltose showed that production of EPS and cell dry weight were boosted by maltose supplementation. The production of EPS (9.1 ± 0.05 µg/ml) and increase in cell dry weight (1.01 ± 0.06 g/l) were comparatively high in Nostoc sp. N27P72 which was isolated from lime stones.The cultures were evaluated for their ability to remove Cu (II), Cr (III), and Ni (II) in culture media with and without maltose. The crude EPS showed metal adsorption capacity assuming the order Ni (II) > Cu (II) > Cr (III) from the metal-binding experiments.Nickel was preferentially biosorbed with a maximal uptake of 188.8 ± 0.14 mg (g cell dry wt) -1 crude EPS. We found that using maltose as a carbon source can increase the production of EPS, protein, and carbohydrates content and it could be a significant reason for the high ability of metal absorbance. FT-IR spectroscopy revealed that the treatment with Ni can change the functional groups and glycoside linkages in both strains. Results of Gas Chromatography-Mass Spectrometry (GC-MS) were used to determine the biochemical composition of Nostoc sp. N27P72, showed that strong Ni (II) removal capability could be associated with the high silicon containing heterocyclic compound and aromatic diacid compounds content. CONCLUSION: The results of this studyindicatede that strains Nostoc sp. N27P72 can be a good candidate for the commercial production of EPS and might be utilized in bioremediation field as an alternative to synthetic and abiotic flocculants.

OXA-CuS@UiO-66-NH2 as a drug delivery system for Oxaliplatin to colorectal cancer cells.

In this work, UiO-66-NH2 was used to prepare a new delivery system by incorporating copper sulfide (CuS) into the pores. The CuS nanoparticles (NPs) were prepared to enhance the anticancer effects of Oxaliplatin (OXA) against colorectal cancer. The oxaliplatin was loaded into CuS@UiO-66-NH2. To characterize and investigate their cytotoxicity effects, powder X-ray diffraction (PXRD), Fourier transformation infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) analysis, UV-Visible analysis, inductively coupled plasma mass spectrometry (ICP-MS), and MTT assay were considered to be performed. According to the observations, the cytotoxicity of OXA-CuS@UiO-66-NH2 was greater than that of the OXA alone.

Mono- and bis-pyrazolophthalazines: Design, synthesis, cytotoxic activity, DNA/HSA binding and molecular docking studies.

In an attempt to find new potent cytotoxic compounds, several mono- and bis-pyrazolophthalazines 4a-m and 6a-h were synthesized through an efficient, one-pot, three- and pseudo five-component synthetic approach. All derivatives were evaluated for their in vitro cytotoxic activities against four human cancer cell lines of A549, HepG2, MCF-7, and HT29. Compound 4e showed low toxicity against normal cell lines (MRC-5 and MCF 10A, IC50 > 200 µM) and excellent cytotoxic activity against A549 cell line with IC50 value of 1.25 ± 0.19 µM, which was 1.8 times more potent than doxorubicin (IC50 = 2.31 ± 0.13 µM). In addition, compound 6c exhibited remarkable cytotoxic activity against A549 and MCF-7 cell lines (IC50 = 1.35 ± 0.12 and 0.49 ± 0.01 µM, respectively), more than two-fold higher than that of doxorubicin. The binding properties of the best active mono- and bis-pyrazolophthalazine (4e and 6c) with HSA and DNA were fully evaluated by various techniques including UV-Vis absorption, circular dichroism (CD), Zeta potential and dynamic light scattering analyses indicating interaction of the compounds with the secondary structure of HSA and significant change of DNA conformation, presumably via a groove binding mechanism. Additionally, molecular docking and site-selective binding studies confirmed the fundamental interaction of compounds 4e and 6c with base pairs of DNA. Compounds 4e and 6c showed promising features to be considered as potential lead structures for further studies in cancer therapy.

Effect of Low-Level Laser Therapy and Sinensetin (Combination therapy) on Tumor Cells (Hela) and Normal Cells (CHO).

Introduction: Cervical and ovarian cancers are well-known causes of death among women in developing countries. There are various technologies to treat cancer cells, but the polyphenolic compound is a natural one and has an anti-cancer effect. Sinensetin is one of them and is found in Orthosiphon stamineus and citrus fruits. Since combination therapy is more effective than drug treatment alone, in this study, we investigated combination therapy using sinensetin and low-level laser therapy (LLLT) to enhance treatment. Methods: The cancer cells purchased from Pasteur Institute, Iran, were cultured. The cells were treated with various concentrations of sinensetin (0.1-1-10-50,150 µg/mL for 24 hours), wavelengths of laser therapy (660 nm) and power density (3 J/cm2) for different times)30, 60, and 90 seconds) separately. Furthermore, sensitivity of cells to sinensetin, LLLT and combined therapy was determined by clonogenic assays. To measure DNA damage and repair at individual cell level used comet assay. To examine the intracellular generation of reactive oxygen species used 2',7'-dichlorodihydrofluorescein (DCFH) as an intracellular probe. To analyze data we used SPSS software and comparison between groups was used (ANOVA) and t test statistical analyses were performed using SPSS 17 software. Data are presented as means - standard error of mean. The level of statistical significance was set at a two-tailed P value of 0.05. All tests were performed in triplicate. Results: Our results demonstrated that the doubling time for CHO is more than Hella cells, with 20.7 and 27.7 h for each cell respectively. The pretreatments (first LLLT, then sinensetin) can decrease the viability of both cell lines more than the first treatment (sinensetin + LLLT). In the clonogenic assay, the pretreatment of cells with LLLT and Sinensetin significantly reduced the surviving fraction of both cell lines. MTT results showed that pretreatment with LLLT and Sinensetin can increase cell death compared to Sinensetin and LLLT alone. Production of ROS within the cell was enhanced with LLLT + sinensetin. Conclusion: Our result indicated that combined therapy with LLLT and Sinensetin can treat CHO and Hela cells better than the other groups. Combination treatment with sinensetin-LLLT and the other treatment means, sinensetin and LLLT alone, did not change the cell viability significantly.

The Effects of Paclitaxel in the Combination of Diamond Nanoparticles on the Structure of Human Serum Albumin (HSA) and Their Antiproliferative Role on MDA-MB-231cells.

Since the interactions of anti-cancer agents with blood constituents, in particular with human serum albumin (HSA) may have a major impact on drug pharmacology, the present study designed to provide a fundamental understanding of the interaction of nanodiamonds (NDs) together with paclitaxel (PTX) with HSA in detail for the first time. The UV-Vis, steady-state fluorescence, far-UV CD and zeta potential results displayed that PTX + NDs could form a complex with HSA. Additionally, the values of binding constants and ΔG° showed that PTX + NDs interact strongly with HSA compared to PTX or NDs alone and the hydrophobic force plays a major role in this interaction. Moreover, the in vitro release behavior of PTX + NDs form HSA can be regulated at dissimilar pH levels. The anticancer property of 0.5 µM PTX + 20 µM NDs by MTT assay demonstrates that this combination can tremendously diminish the proliferation of MDA-MB-231cells compared to PTX or NDs alone. Altogether, the structure of HSA changed moderately in the presence of PTX + NDs and PTX + NDs can promote mortality of MDA-MB-231 cells besides those mortality effects induced via PTX or NDs alone. The results obtained from this study can help in understanding the pharmacokinetic properties of PTX + NDs.

Structural effects of Diamond nanoparticles and Paclitaxel combination on calf thymus DNA.

The combination effects of nanodiamonds (NDs) and Paclitaxel (PTX) on the DNA structure were examined. The UV-Visible, steady-state and time-resolved fluorescence spectroscopy, CD, viscosity and zeta potential results showed that PTX + NDs could form a complex via groove binding mechanism. The values of binding constants, ΔG° and ΔH° and ΔS° values showed that PTX + NDs interact strongly with DNA and the hydrophobic force plays main role in this interaction. The ΔG25ο and Tm study indicated the instability of DNA in presence of PTX + NDs. This study demonstrated that NDs could enhance the effect of PTX on DNA structure as well as its affinity and binding to DNA.

Structural characterization of recombinant streptokinase following recovery from inclusion bodies using different chemical solubilization treatments.

Circular dichroism (CD) in far-UV region was employed to study the extent of changes occurred in the secondary structures of recombinant streptokinase (rSK), solubilized from inclusion bodies (IBs) by different chemicals and refolded/purified by chromatographic techniques. The secondary structure distribution of rSK, obtained following different chemical solubilization systems, was varied and values in the range of 12.4-14.5% α-helices, 40-51% ß-sheets and 35.5-48.3% turns plus residual structures were found. With reducing the concentration of chemicals during IB solubilization, the content of turns plus random coils was diminished and simultaneously the amounts of α- and ß-sheets were increased. These changes in the secondary structures would lower the hydrophobicity along with the chance of protein aggregation and expose the hydrophilic regions of the protein. Therefore, these alterations in the secondary structures, occurred following efficient IBs solubilization by low concentration of chemicals, could be related to enhancement in rSK biological potency previously observed.

Structural Changes of Human Serum Albumin (HSA) in Simulated Microgravity.

BACKGROUND: Nowadays, the biological effects of microgravity have been the subject of various experimental researches. Microgravity has been confirmed to affect biological systems. Furthermore, as a result of improvement in space technology for instance a manned mission to the moon, probabilities for human exposed to microgravity have incremented undoubtedly. OBJECTIVES: The purpose of this study was to investigate the probable biological effects of microgravity on the human serum albumin (HSA) structure after 3 and 24 h exposure. It is worth mentioning that this is the first effort to investigate the structural alternations of HSA under simulated microgravity condition in biophysico-chemical terms thru different spectroscopic instruments. METHODS: 2D clinostat was utilized for simulating microgravity. The UV-Vis, intrinsic and extrinsic fluorescence, dynamic light scattering (DLS) and circular dichroism (CD) spectra of 3.76 µM HSA in Tris-HCl buffer (pH 7.4, 0.1 M) and 3.76 µM HSA in Tris-HCl buffer (pH 7.4, 0.1 M) kept at simulated microgravity for 3 and 24h were verified. RESULTS: The UV-Visible, near-UV-CD and intrinsic fluorescence spectroscopy represented that microgravity can remarkably change the tertiary structure of HSA. Additionally, the ANS affinity for HSA incremented when the protein was exposed to simulate microgravity compared to unexposed HSA, which may possibly have appeared attributable to expansion of the structure of simulated HSA. Fluorescence quenching by acrylamide demonstrated higher stern-volmer constant for exposed HSA. The results of zeta potential and dynamic light scattering (DLS) experiments depicted that simulated microgravity cause raise in the surface charge and size of HSA. Far-UV CD data demonstrated that simulated microgravity did not perturb the secondary structures of the protein. CONCLUSION: Collectively, our results suggest that HSA after 24 h exposure to microgravity can exhibit a molten globule (MG) structure. This is the first report to demonstrate the molten globule state formation in microgravity condition. Results from this study could give knowledge to understand the role of gravity on protein folding process. In addition, this finding could help to find out safe limits for astronauts and space travelers and to develop adequate countermeasures against any harmful effects of microgravity.

Structural effects of TiO2 nanoparticles and doxorubicin on DNA and their antiproliferative roles in T47D and MCF7 cells.

The structural changes in DNA caused by the combined effects of TiO2 nanoparticles (TiO2 NPs) and doxorubicin (DOX) were investigated along with their corresponding inhibitory roles in the growth of T47D and MCF7 cells. The UV-visible titration studies showed that DOX+ TiO2 NPs could form a novel complex with DNA. The data also reveal that the TiO2-DOX complex forms through a 1:4 stoichiometric ratio in solution. The values of binding constants reveal that DOX+TiO2 NPs interact more strongly with DNA as compared to TiO2 NPs or DOX alone. CD data show that DOX+TiO2 NPs can noticeably cause disturbance on DNA structure compared to TiO2 NPs or DOX alone, considering that DNA is relatively thermally stable in the condition used. The anticancer property of 0.3 µM DOX+ 60 µM TiO2 NPs and 0.4 µM DOX+ 670 µM TiO2 NPs by MTT assay and DAPI stain demonstrates that this combination can tremendously diminish proliferation of T47D and MCF7cells compared to DOX or TiO2 NPs alone. The UV-Vis absorption spectroscopy, flow cytometry and fluorescence microscopy experiments show much more enhancement of DOX uptake through the use of TiO2 NPs. These results reveal that DOX+TiO2 NPs could proffer a novel strategy for the development of promising and efficient chemotherapy agents.