An easy, fast and inexpensive method of preparing a biological specimen for scanning electron microscopy (SEM)

Novel Bis(2-cyanoacrylamide) Linked to Sulphamethoxazole: Synthesis, DNA Interaction, Anticancer, ADMET, Molecular Docking, and DFT Studies

In the light of advancement and potential extensive use of medication design and therapy, new bis(cyanoacrylamides) incorporating sulphamethoxazole derivatives (7 a-7 f) were synthesized and confirmed by different spectral tools. In vitro anticancer activity towards different human cancer cells (HCT116, MDA-MB-231 and A549) was assessed using MTT assay. Among all derivatives, 4C- and 6C-spacer derivatives (7 e and 7 f) had the most potent growth inhibitory activities against HCT116 cells with IC50 values of 39.7 and 28.5 μM, respectively. 7 e and 7 f induced apoptosis and suppressed migration of HCT116 cells. These compounds also induced a significant increase in caspase-3 and CDH1 activities, and a downregulation of Bcl2 using ELISA. pBR322 DNA cleavage activities of cyanoacrylamides were determined using agarose gel electrophoresis. Furthermore, 7 e and 7 f showed good DNA and BSA binding affinities using different spectroscopic techniques. Furthermore, molecular docking for 7 e and 7 f was performed to anticipate their binding capabilities toward various proteins (Bcl2, CDH1 and BSA). The docking results were well correlated with those of experimental results. Additionally, density functional theory and ADMET study were performed to evaluate the molecular and pharmacokinetic features of 7 e and 7 f, respectively. Thus, this work reveals promising antitumor lead compounds that merit future research and activity enhancement.

Novel cyanochalcones as potential anticancer agents: apoptosis, cell cycle arrest, DNA binding, and molecular docking studies

In the light of anticancer drug discovery and development, a new series of cyanochalcones incorporating indole moiety (5a-g) were efficiently synthesized and characterized by different spectral analysis. MTT assay was used to evaluate the antiproliferative activity of the synthesized compounds towards different cancer cells (Hela, MDA-MB-231, A375, and A549) in parallel with normal cells (HSF). Trimethoxy and diethoxy-containing derivatives (5d and 5e) displayed the most selective cytotoxic activities against cervical Hela cells with IC50 values of 8.29 and 11.82 µM, respectively, with great safety pattern toward normal HSF cells (Selectivity index: 21.3 and 13.9, respectively). Therefore, 5d and 5e were chosen to study their effects on apoptosis, cell cycle arrest, and migration of Hela cells using flow cytometric analysis and wound healing assay. They induced apoptosis and cell cycle arrest at the S phase and impaired migration of HeLa cells. Regarding their effects on the expression profile of crucial genes related to the potential anticancer activities, 5d and 5e remarkably upregulated caspase 3 and Beclin1 and downregulated cyclin A1, CDK2, CDH2, MMP9, and HIF1A using qRT-PCR and ELISA techniques. UV-Vis spectral measurement demonstrated the ability of 5d and 5e to bind CT-DNA efficiently with Kb values of 3.7 × 105 and 1 × 105 M-1, respectively. Moreover, in silico molecular docking was performed to assess the binding affinities of the compounds toward the active sites of Bcl2, CDK2, and DNA. Therefore, cyanochalcones 5d and 5e might be promising anticancer agents and could offer a scientific basis for intensive research into cancer chemotherapy.Communicated by Ramaswamy H. Sarma.

Application of Thymol Vapors to Control Postharvest Decay Caused by Penicillium digitatum and Lasiodiplodia theobromae in Grapefruit

Two of the major postharvest diseases impacting grapefruit shelf life and marketability in the state of Florida (USA) are stem-end rot (SER) caused by Lasiodiplodia theobromae and green mold (GM) caused by Penicillium digitatum. Here, we investigated the in vitro and in vivo efficacy of vapors of thymol, a natural compound found in the essential oil of various plants and the primary constituent of thyme (Thymus vulgaris) oil, as a potential solution for the management of GM and SER. Thymol vapors at concentrations lower than 10 mg L-1 significantly inhibited the mycelial growth of both pathogens, causing severe ultrastructural damage to P. digitatum conidia. In in vivo trials, the incidence and lesion area of GM and SER on inoculated grapefruit were significantly reduced after a 5 d exposure to 50 mg L-1 thymol vapors. In addition, the in vitro and in vivo sporulation of P. digitatum was suppressed by thymol. When applied in its vapor phase, thymol had no negative effect on the fruit, neither introducing perceivable off-flavor nor causing additional weight loss. Our findings support the pursuit of further studies on the use of thymol, recognized as safe for human health and the environment, as a promising strategy for grapefruit postharvest disease management.

Differences and Similarities between Colorectal Cancer Cells and Colorectal Cancer Stem Cells: Molecular Insights and Implications

Malignant tumors are formed by diverse groups of cancer cells. Cancer stem cells (CSCs) are a subpopulation of heterogeneous cells identified in tumors that have the ability to self-renew and differentiate. Colorectal cancer (CRC), the third most frequent malignant tumor, is progressively being supported by evidence suggesting that CSCs are crucial in cancer development. We aim to identify molecular differences between CRC cells and CRC CSCs, as well as the effects of those differences on cell behavior in terms of migration, EMT, pluripotency, morphology, cell cycle/control, and epigenetic characteristics. The HT-29 cell line (human colorectal adenocarcinoma) and HT-29 CSCs (HT-29 CD133+/CD44+ cells) were cultured for 72 h. The levels of E-cadherin, KLF4, p53, p21, p16, cyclin D2, HDAC9, and P300 protein expression were determined using immunohistochemistry staining. The migration of cells was assessed by employing the scratch assay technique. Additionally, the scanning electron microscopy method was used to examine the morphological features of the cells, and their peripheral/central elemental ratios were compared with the help of EDS. Furthermore, a Muse cell cycle kit was utilized to determine the cell cycle analysis. The HT-29 CSC group exhibited high levels of expression for E-cadherin, p53, p21, p16, cyclin D2, HDAC9, and P300, whereas KLF4 was found to be high in the HT-29. The two groups did not exhibit any statistically significant differences in the percentages of cell cycle phases. The identification of specific CSC characteristics will allow for earlier cancer detection and the development of more effective precision oncology options.

Amyl acetate: an alternative technique to dry mount Chalcidoidea (Hymenoptera) from alcohol, faster and inexpensively

Ethanol (EtOH) 70% is commonly used in collections to preserve and store many unprepared soft-bodied Chalcidoidea. Specimens air-dried directly from alcohol, however, often suffer from collapse of some body parts, making subsequent observation of their morphology difficult or even impossible. We propose an inexpensive method for processing and dry-mounting specimens of Chalcidoidea, using a chemical process including amyl acetate. Four treatments using amyl acetate at different concentrations and exposure times were evaluated for specimens of Eulophidae, Mymaridae, Encyrtidae, Aphelinidae, Pteromalidae, and Trichogrammatidae. Treatment with amyl acetate resulted in specimens of consistently higher quality. Based on our results, treatment of specimens for 1 h with 50:50 amyl acetate and ethanol mixture, followed by treatment for 1 h with 100% amyl acetate, yielded specimens adequate for morphological observations for most of the families. Further experiments are required, however, to optimize this approach for Trichogrammatidae and Eulophidae. This method is a relatively simple, inexpensive, and safe alternative to other methods commonly used for restoring Chalcidoidea preserved in alcohol.

Stemness potency and structural characteristics of thyroid cancer cell lines

BACKGROUND

Thyroid cancer is the most frequent type of endocrine malignancy. Thyroid carcinomas are derived from the follicular epithelium and classified as papillary (PTC) (85%), follicular (FTC) (12%), and anaplastic (ATC) (<3%). Thyroid cancer could arise from thyroid cancer stem-like cells (CSCs). CSCs are cancer cells that feature stem-like properties. Kruppel-like factor (KLF4) and Stage-spesific embryonic antigen 1 (SSEA-1) are types of stem cell markers. Filamentous actin (F-actin) is an essential part of the cellular cytoskeleton. The purpose of this study was to evaluate the stem cell potency and the spatial distribution of the cytoskeletal element F-actin in PTC, FTC, and ATC cell lines.

MATERIALS AND METHODS

Normal thyroid cell line (NTC) Nthy-ori-3-1, PTC cell line BCPAP, FTC cell line FTC-133 and ATC cell line 8505c were stained with SSEA-1 and KLF4 for stem cell potency and F-actin for cytoskeleton. The morphological properties of cells were assessed by a scanning electron microscope (SEM) and elemental ratios were compared with EDS.

RESULTS

PTCs had greater percentages of SSEA-1 and KLF4 protein intensity (0.32% and 0.49%, respectively) than NTCs. ATCs had a greater proportion of KLF4 expression (0.8%) than NTCs. NTCs and FTCs had increased F-actin intensity across the cell, but PTCs had the lowest among these four cell lines. NTCs and PTCs, as well as NTCs and FTCs, have statistically identical aspect ratios and round values. These values, however, were statistically different in ATCs.

CONCLUSION

The study of stem cell markers and the cytoskeletal element F-actin in cancer and normal thyroid cell lines may assist in the identification of new therapeutic targets and contribute in the understanding of treatment resistance mechanisms.

A Simple Protocol for Sample Preparation for Scanning Electron Microscopic Imaging Allows Quick Screening of Nanomaterials Adhering to Cell Surface

Preparing biological specimens for scanning electron microscopy (SEM) can be difficult to implement, as it requires specialized equipment and materials as well as the training of dedicated personnel. Moreover, the procedure often results in damage to the samples to be analyzed. This work presents a protocol for the preparation of biological samples to evaluate the adherence of nanomaterials on the cell surface using SEM. To this end, we used silicon wafers as a substrate to grow cells and replaced difficult steps such as the critical point drying of the samples in order to make the method quicker and easier to perform. The new protocol was tested using two different types of cells, i.e., human osteosarcoma cells and adipose-derived mesenchymal stem cells, and it proved that it can grossly preserve cell integrity in order to be used to estimate nanomaterials' interaction with cell surfaces.

Evaluation of Polysaccharide-Peptide Conjugates Containing the RGD Motif for Potential Use in Muscle Tissue Regeneration

New scaffold materials composed of biodegradable components are of great interest in regenerative medicine. These materials should be: stable, nontoxic, and biodegrade slowly and steadily, allowing the stable release of biodegradable and biologically active substances. We analyzed peptide-polysaccharide conjugates derived from peptides containing RGD motif (H-RGDS-OH (1), H-GRGDS-NH₂ (2), and cyclo(RGDfC) (3)) and polysaccharides as scaffolds to select the most appropriate biomaterials for application in regenerative medicine. Based on the results of MTT and Ki-67 assays, we can state that the conjugates containing calcium alginate and the ternary nonwoven material were the most supportive of muscle tissue regeneration. Scanning electron microscopy imaging and light microscopy studies with hematoxylin-eosin staining showed that C2C12 cells were able to interact with the tested peptide-polysaccharide conjugates. The release factor (Q) varied depending on both the peptide and the structure of the polysaccharide matrix. LDH, Alamarblue^®, Ki-67, and cell cycle assays indicated that peptides 1 and 2 were characterized by the best biological properties. Conjugates containing chitosan and the ternary polysaccharide nonwoven with peptide 1 exhibited very high antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae. Overall, the results of the study suggested that polysaccharide conjugates with peptides 1 and 2 can be potentially used in regenerative medicine.

A comparative account of coelomocyte of earthworm ecotypes with reference to its morphology, morphometry, density, phagocytosis, autofluorescence, and oxidative status

Earthworms inhabit different strata of moist soil. Epigeic and endogeic earthworms prefer superficial and inner stratum of soil respectively, whereas, semiaquatic species are distributed around hydrated soil near ponds and lakes. Coelomocytes, the chief immunoeffector cells of coelomic origin, perform diverse physiological functions like phagocytosis, maintenance of cellular homeostasis, and acid-base balance of coelomic fluid, graft rejection, elicitation of cytotoxic, and oxidative responses under the challenges of pathogens and toxins. The present study aims to analyze selected morphological and functional parameters in three differentially adapted Indian earthworms of nonsimilar habitats. Coelomocytes of Glyphidrilus tuberosus (Stephenson, 1916) (semiaquatic), Perionyx excavatus (Perrier, 1872) (epigeic), and Eutyphoeus orientalis (Beddard, 1883) (endogeic) were isolated for morphological and morphometric analyses and subjected to determination of phagocytic, oxidative, and cytotoxic responses. Activities of phenoloxidase, pro, and antioxidant enzymes, and autofluorescence were determined in the extruded coelomocytes of earthworms of three contrasting habitats. The differential result may be correlated with species-specific responses and variation in habitat preference and related adaptation.

Electrochemically differentiated human MSCs biosensing platform for quantification of nestin and β-III tubulin as whole-cell system

Polydimethylsiloxane (PDMS) on ITO substrate was used to create a well with conducting surface to adhere human mesenchymal stem cells (hMSCs) and provide electrochemical stimulation for inducing their differentiation into neural-like cells. The cells that received electrochemical stimulation did not show any noticeable change in their viability and proliferation. The cell morphology of the differentiated hMSCs adherent on ITO showed outgrowth and elongation in one dimension, resembling neural-like cells. Immunocytochemistry assessment by quantifying the expression of nestin and β-III tubulin also confirmed the differentiation of hMSCs. These differentiated hMSCs adherent on ITO were used as electrochemical biosensing platform for differential pulse voltammetry (DPV) measurement for selectively quantifying cell surface markers expressed by neural stem cells and mature neurons. The variation of nestin antibodies concentrations from 9 μU to 27 μU showed a linear increase in DPV current with a detection sensitivity of ∼28 nA/μU of antibody. Varying concentrations of β-III tubulin antibodies from 30 μU to 210 μU showed a linear increase in DPV current with a detection sensitivity of ∼2.0 nA/μU of antibody. The highest expression level of cell surface marker corresponding to β-III tubulin in total adherent cells on ITO was calculated. It was in the order of 10^-8 U of antibodies/cell, representing the total population of mature neuron cells. This new way of detection may rapidly assess the quantitative expression of cell surface markers/antigens.