ABSTRACT
In these studies, we designed and investigated the potential anticancer activity of five iron(II) cyclopentadienyl complexes bearing different phosphine and phosphite ligands. All complexes were characterized with spectroscopic analysis viz. NMR, FT-IR, ESI-MS, UV-Vis, fluorescence, XRD (for four complexes) and elemental analyses. For biological studies, we used three types of cells-normal peripheral blood mononuclear (PBM) cells, leukemic HL-60 cells and non-small-cell lung cancer A549 cells. We evaluated cell viability and DNA damage after cell incubation with these complexes. We observed that all iron(II) complexes were more cytotoxic for HL-60 cells than for A549 cells. The complex CpFe(CO)(P(OPh)3)(η1-N-maleimidato) 3b was the most cytotoxic with IC50 = 9.09 µM in HL-60 cells, IC50 = 19.16 µM in A549 and IC50 = 5.80 µM in PBM cells. The complex CpFe(CO)(P(Fu)3)(η1-N-maleimidato) 2b was cytotoxic only for both cancer cell lines, with IC50 = 10.03 µM in HL-60 cells and IC50 = 73.54 µM in A549 cells. We also found the genotoxic potential of the complex 2b in both types of cancer cells. However, the complex CpFe(CO)2(η1-N-maleimidato) 1 which we studied previously, was much more genotoxic than complex 2b, especially for A549 cells. The plasmid relaxation assay showed that iron(II) complexes do not induce strand breaks in fully paired ds-DNA. The DNA titration experiment showed no intercalation of complex 2b into DNA. Molecular docking revealed however that complexes CpFe(CO)(PPh3) (η1-N-maleimidato) 2a, 2b, 3b and CpFe(CO)(P(OiPr)3)(η1-N-maleimidato) 3c have the greatest potential to bind to mismatched DNA. Our studies demonstrated that the iron(II) complex 1 and 2b are the most interesting compounds in terms of selective cytotoxic action against cancer cells. However, the cellular mechanism of their anticancer activity requires further research.
Subject(s)
Antineoplastic Agents , Carcinoma, Non-Small-Cell Lung , Coordination Complexes , Lung Neoplasms , Phosphines , Phosphites , Humans , Molecular Docking Simulation , Coordination Complexes/chemistry , Iron , Leukocytes, Mononuclear/metabolism , Spectroscopy, Fourier Transform Infrared , DNA/metabolism , Maleimides , Ferrous Compounds/pharmacology , Antineoplastic Agents/chemistry , Ligands , Cell Line, TumorABSTRACT
Bacterial infections caused by Staphylococcus aureus are one of the growing concerns for human health care management globally. Antibiotic-associated adverse effects and the emergence of bacterial resistant strains necessitate the development of an alternative yet effective approach. Nanoemulsion-based therapy has emerged as a potential therapeutic strategy to combat bacterial infestation. Herein, we designed a cationic metal nanoparticle-conjugated fusogenic nanoemulsion (CFusoN) as a lipid solubilizing nanovesicle for the effective treatment of S. aureus infection with a killing efficiency of 99.999%. The cationic nanoparticle-conjugated nanoemulsion (viz. NECNP) (24.4 ± 2.9 mV) electrostatically bound with the negatively charged bacterial cell membrane (-10.2 ± 3.7 mV) causing alteration of the bacterial surface charge. The fluorometric and flow cytometry studies confirmed the bacterial membrane depolarization and altered cell membrane permeability leading to cell death. The atomic force microscopic studies further demonstrated the damage of the cellular ultrastructure, while the transmission electron microscopic image and membrane lipid solubilization analysis depicted the solubilization of the bacterial membrane lipid bilayer along with the leakage of the intracellular contents. The cell membrane fatty acid analysis revealed that the methyl esters of palmitic acid, stearic acid and octadecadienoic acid isomers were solubilized after the treatment of S. aureus with CFusoN. The bactericidal killing efficiency of CFusoN is proposed to occur through the synergistic efficacy of the targeted attachment of CNP to the bacterial cells along with the lipid solubilization property of NE. Interestingly, NECNP didn't elicit any in vitro hemolytic activity or cytotoxicity against red blood cells (RBCs) and L929 fibroblast cells, respectively, at its bactericidal concentration. Furthermore, a porcine skin wound infection model exhibited the enhanced wound cleansing potency of CFusoN in comparison to the commercially available wound cleansers. The obtained antibacterial activity, biocompatibility and skin wound disinfection efficacy of the NECNP demonstrated the formulation of a cell targeted CFusoN as a promising translatable strategy to combat bacterial infection.
Subject(s)
Nanoparticles , Staphylococcal Infections , Humans , Staphylococcus aureus , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/therapeutic use , Staphylococcal Infections/drug therapy , Staphylococcal Infections/microbiology , Nanoparticles/therapeutic use , Nanoparticles/chemistry , Bacteria , Membrane Lipids/pharmacology , Membrane Lipids/therapeutic useABSTRACT
Segmentation architectures based on deep learning proficient extraordinary results in medical imaging technologies. Computed tomography (CT) images and Magnetic Resonance Imaging (MRI) in diagnosis and treatment are increasing and significantly support the diagnostic process by removing the bottlenecks of manual segmentation. Cardiac Magnetic Resonance Imaging (CMRI) is a state-of-the-art imaging technique used to acquire vital heart measurements and has received extensive attention from researchers for automatic segmentation. Deep learning methods offer high-precision segmentation but still pose several difficulties, such as pixel homogeneity in nearby organs. The motivated study using the attention mechanism approach was introduced for medical images for automated algorithms. The experiment focuses on observing the impact of the attention mechanism with and without pretrained backbone networks on the UNet model. For the same, three networks are considered: Attention-UNet, Attention-UNet with resnet50 pretrained backbone and Attention-UNet with densenet121 pretrained backbone. The experiments are performed on the ACDC Challenge 2017 dataset. The performance is evaluated by conducting a comparative analysis based on the Dice Coefficient, IoU Coefficient, and cross-entropy loss calculations. The Attention-UNet, Attention-UNet with resnet50 pretrained backbone, and Attention-UNet with densenet121 pretrained backbone networks obtained Dice Coefficients of 0.9889, 0.9720, and 0.9801, respectively, along with corresponding IoU scores of 0.9781, 0.9457, and 0.9612. Results compared with the state-of-the-art methods indicate that the methods are on par with, or even superior in terms of both the Dice coefficient and Intersection-over-union.
Subject(s)
Magnetic Resonance Imaging , Tomography, X-Ray Computed , HumansABSTRACT
Wound dressing with poor antibacterial properties, the tendency to adhere to the wound site, poor mechanical strength, and lack of porosity and flexibility are the major cause of blood loss, delayed wound repair, and sometimes causes death during the trauma or injury. In such cases, hydrogel-based antibacterial wound dressing would be a boon to the existing dressing as the moist environment will maintain the cooling temperate and proper exchange of atmosphere around the wound. In the present study, the multifunctional graphene with silver and ε-Poly-l-lysine reinforced into the chitosan matrix (CGAPL) was prepared as a nanobiocomposite wound dressing. The contact angle measurement depicted the hydrophilic property of CGAPL nanobiocomposite dressing (water contact angle 42°), while the mechanical property was 78.9 MPa. The antibacterial and cell infiltration study showed the antimicrobial property of CGAPL nanobiocomposite wound dressing. It also demonstrated no cytotoxicity to the L929 fibroblast cells. Chorioallantoic Membrane (CAM) assay showed the pro-angiogenic potential of CGAPL nanobiocomposite wound dressing. In-vitro scratch wound assay confirmed the migration of cells and increased cell adhesion and proliferation within 18 h of culture on the surface of CGAPL nanobiocomposite dressing. Later, the in-vivo study in the Wistar rat model showed that CGAPL nanobiocomposite dressing significantly enhanced the wound healing process as compared to the commercially available wound dressing Tegaderm (p-value <0.01) and Fibroheal@Ag (p-value <0.005) and obtained complete wound closure in 14 days. Histology study further confirmed the complete healing process, re-epithelization, and thick epidermis tissue formation. The proposed CGAPL nanobiocomposite wound dressing thus offers a novel wound dressing material with an efficient and faster wound healing property.
Subject(s)
Chitosan , Graphite , Metal Nanoparticles , Rats , Animals , Chitosan/chemistry , Silver/pharmacology , Silver/chemistry , Metal Nanoparticles/chemistry , Antimicrobial Peptides , Rats, Wistar , Bandages , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , HydrogelsABSTRACT
In these studies, we designed and investigated cyto- and genotoxic potential of five ruthenium cyclopentadienyl complexes bearing different phosphine and phosphite ligands. All of the complexes were characterized with spectroscopic analysis (NMR, FT-IR, ESI-MS, UV-vis, fluorescence and XRD (for two compounds)). For biological studies, we used three types of cells - normal peripheral blood mononuclear (PBM) cells, leukemic HL-60 cells and doxorubicin-resistance HL-60 cells (HL-60/DR). We compared the results obtained with those obtained for the complex with maleimide ligand CpRu(CO)2(η1-N-maleimidato) 1, which we had previously reported. We observed that the complexes CpRu(CO)(PPh3)(η1-N-maleimidato) 2a and CpRu(CO)(P(OEt)3)(η1-N-maleimidato) 3a were the most cytotoxic for HL-60 cells and non-cytotoxic for normal PBM cells. However, complex 1 was more cytotoxic for HL-60 cells than complexes 2a and 3a (IC50 = 6.39 µM vs. IC50 = 21.48 µM and IC50 = 12.25 µM, respectively). The complex CpRu(CO)(P(OPh)3)(η1-N-maleimidato) 3b is the most cytotoxic for HL-60/DR cells (IC50 = 104.35 µM). We found the genotoxic potential of complexes 2a and 3a only in HL-60 cells. These complexes also induced apoptosis in HL-60 cells. Docking studies showed that complexes 2a and CpRu(CO)(P(Fu)3)(η1-N-maleimidato) 2b have a small ability to degrade DNA, but they may cause a defect in DNA damage repair mechanisms leading to cell death. This hypothesis is corroborated with the results obtained in the plasmid relaxation assay in which ruthenium complexes bearing phosphine and phosphite ligands induce DNA breaks.
Subject(s)
Antineoplastic Agents , Coordination Complexes , Neoplasms , Phosphites , Ruthenium , Humans , Ruthenium/pharmacology , Ruthenium/chemistry , Ligands , Leukocytes, Mononuclear , Spectroscopy, Fourier Transform Infrared , Maleimides/pharmacology , Coordination Complexes/chemistry , Antineoplastic Agents/chemistry , Cell Line, TumorABSTRACT
Cardiac magnetic resonance imaging (CMRI) is a non-invasive imaging technique to analyse the structure and function of the heart. It was enhanced considerably over several years to deliver functional information for diagnosing and managing cardiovascular disease. CMRI image delivers non-invasive, clear access to the heart and great vessels. The segmentation of CMRI provides quantification parameters such as myocardial viability, ejection fraction, cardiac chamber volume, and morphological details. In general, experts interpret the CMR images by delineating the images manually. The manual segmentation process is time-consuming, and it has been observed that the final observation varied with the opinion of the different experts. Convolution neural network is a new-age technology that provides impressive results compared to manual ones. In this study convolution neural network model is used for the segmentation task. The neural network parameters have been optimized to perform on the novel data set for accurate predictions. With other parameters, epochs play an essential role in training the network, as the network should not be under-fitted or over-fitted. The relationship between the hyperparameter epoch and accuracy is established in the model. The model delivers the accuracy of 0.88 in terms of the IoU coefficient.
Subject(s)
Deep Learning , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Neural Networks, Computer , Heart/diagnostic imagingABSTRACT
We describe a 3-month-old baby who presented with a nonresolving pneumonia which failed to respond to antibiotic therapy. An underlying congenital pulmonary adenomatous malformation was suspected. On thoracotomy, she was found to have a tuberculous mediastinal abscess which was drained. Mediastinal abscess is a rare occurrence in childhood tuberculosis.
ABSTRACT
Targeted drug delivery has become attention in chemotherapy during the last decade. The principle of chemotherapy seeks maximum effect to the desired site and the minimum impact to other undesired sites of action. The nanoparticulated drug delivery system progressed a lot in this aspect in the last twenty years. Plant-derived natural products and their semisynthetic analogues boosted chemotherapy through their excellent mechanistic approach to killing cancer cells. Keeping in mind the available molecular targets in colorectal carcinoma (CRC), in this article, we proposed a peptide conjugated novel polymeric nanoparticle to deliver garcinol against colorectal carcinoma. Integrin binding peptide iRGD, sequence c(CRGDKGPDC), has been selected as a targeting moiety, as most CRC overexpress integrins. We encapsulated garcinol in biodegradable polymeric nanoparticle (PLGA)-conjugated with iRGD peptide on the particles' surface, and analyzed its (iRGD-GAR-NP's) in vitro and in vivo antineoplastic potential against CRC in a comparative way with gracinol (GAR) and garcinol-loaded PLGA nanoparticles (GAR-NP). In vitro cellular studies on human CRC cell lines, HCT116 and HT-29, revealed the superior cytotoxic potential of iRGD-GAR-NP over GAR and GAR-NP. The IC50 value on HCT116 cells was reduced by 2.3 times compared to GAR upon the application of iRGD-GAR-NP. At equivalent doses, iRGD-GAR-NP induced higher apoptosis in HCT116 cells and caused blockage of cell cycle at G0/G1 phase of the same. iRGD-GAR-NP increased the apoptotic population of HCT116 cells by 2.5 times compared to GAR. In vivo biodistribution study uncoiled the ability of GAR-NP and iRGD-GAR-NP to accumulate in the colons of dimethyl hydrazine-induced CRC-bearing Sprague-Dawely (SD) rats. In vivo antitumor efficacy study demonstrated the better effect of iRGD-GAR-NP to reduce CRC tumor progression in experimental animals. The survival rate of animals was also increased by 166% in the case of iRGD-GAR-NP compared to CRC-bearing animals received no treatment.
Subject(s)
Antineoplastic Agents , Colorectal Neoplasms , Nanoparticles , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Colorectal Neoplasms/drug therapy , Humans , Oligopeptides , Polylactic Acid-Polyglycolic Acid Copolymer/therapeutic use , Polymers/therapeutic use , Rats , Terpenes , Tissue DistributionABSTRACT
Developing new underwater glue adhesives with robust and repeatable adhesion to various surfaces is promising and useful in marine life and medical treatments. In this work, we developed a novel glue based on a copolymer with a cation-co-aromatic sequence where the cationic units contain both catechol and positively charged sites. The glue consists of a crosslinked copolymer of poly(2-hydroxy-3-phenoxypropyl acrylate-co-3-(5-(3,4 dihydroxyphenyl)-4-oxo-3 N-pentyl)imidazolium) bromide in dimethyl sulfoxide. Solidification of the glue, triggered by contact with water, undergoes a coacervation stage and causes a drastic growth of its mechanical properties over time. The glue demonstrates fast-developing, strong, and repeatable underwater adhesion to different materials and can maintain its strength for a long time. The adhesion strength tends to increase with the surface energy of the substrate material, to a maximum value of 160 kPa found in plywood. Experiments conducted in aqueous media with different pH and ionic strengths, including physiological conditions and seawater, showed an even stronger adhesion than that evolved in deionized water. Thus, the developed glue is a promising candidate for use in marine life, tissue adhesives, and other freshwater and saline water applications.
Subject(s)
Adhesives , Polymers , Adhesives/chemistry , Cations , Polymers/chemistryABSTRACT
Neurological disorders (NDs) are becoming more common, posing a concern to pregnant women, parents, healthy infants, and children. Neurological disorders arise in a wide variety of forms, each with its own set of origins, complications, and results. In recent years, the intricacy of brain functionalities has received a better understanding due to neuroimaging modalities, such as magnetic resonance imaging (MRI), magnetoencephalography (MEG), and positron emission tomography (PET), etc. With high-performance computational tools and various machine learning (ML) and deep learning (DL) methods, these modalities have discovered exciting possibilities for identifying and diagnosing neurological disorders. This study follows a computer-aided diagnosis methodology, leading to an overview of pre-processing and feature extraction techniques. The performance of existing ML and DL approaches for detecting NDs is critically reviewed and compared in this article. A comprehensive portion of this study also shows various modalities and disease-specified datasets that detect and records images, signals, and speeches, etc. Limited related works are also summarized on NDs, as this domain has significantly fewer works focused on disease and detection criteria. Some of the standard evaluation metrics are also presented in this study for better result analysis and comparison. This research has also been outlined in a consistent workflow. At the conclusion, a mandatory discussion section has been included to elaborate on open research challenges and directions for future work in this emerging field.
ABSTRACT
We report a 4-month-old baby presenting with bilateral congenital lobar emphysema. A two-staged bilateral lobectomy was planned, but bilateral lobectomy had to be performed as a single-staged procedure. Data are scarce on the appropriate approach to children with bilateral involvement. Both single-staged and two-staged procedures have shown variable success.
ABSTRACT
Owing to the emergence of antibiotic-resistant strains, bacterial infection and biofilm formation are growing concerns in healthcare management. Herein, we report an eco-benign strategy for the synthesis and functionalization of graphene-silver (rGOAg) nanocomposites with an antimicrobial peptide (AMP) for the treatment of Staphylococcus aureus infection. The synthesis of rGOAg nanocomposites was carried out by simple microwave reduction, and the as-synthesized rGOAg was covalently functionalized with an AMP. As a natural AMP, poly-l-lysine (PLL) functionalization of rGOAg enhanced the antibacterial efficacy and target specificity against the S. aureus biofilm. The robust bactericidal efficiency and biofilm disruption by AMP-functionalized rGOAg (designated as GAAP) occurred through the "contact-kill-release" mode of action, where the electrostatic interaction with bacterial cells together with intracellular ROS generation induced physical disruption to the cell membrane. The internalization of GAAP into the cytoplasm through the damaged cell membrane caused an outburst of intracellular proteins and DNA. Crystal violet staining along with fluorescence and confocal microscopic images showed an effective inhibition and disruption of the S. aureus biofilm upon treatment with GAAP. PLL functionalization also prevented the dissolution of Ag+ ions and thereby minimized the in vitro toxicity of GAAP to the 3 T6 fibroblast and human red blood cells. The ex vivo rat skin disinfection model further demonstrated the potency of GAAP in eliminating the biofilm formation and disruption of the S. aureus biofilm. The obtained results demonstrated a general approach for designing a functional nanocomposite material to disrupt the mature biofilm and provided a promising strategy for treating bacterial infection.
Subject(s)
Graphite , Nanocomposites , Staphylococcal Infections , Animals , Anti-Bacterial Agents/pharmacology , Antimicrobial Peptides , Biofilms , Rats , Silver/pharmacology , Staphylococcal Infections/drug therapy , Staphylococcus aureusABSTRACT
Several approaches for elimination of oral pathogens are being explored at the present time since oral diseases remain prevalent affecting approximately 3.5 billion people worldwide. Need for antimicrobial biomaterials in dental healthcare include but is not restricted to designing resin composites and adhesives for prevention of dental caries. Constant efforts are also being made to develop antimicrobial strategies for clearance of endodontic space prior root canal treatment and for treatment of periimplantitis and periodontitis. This article discusses various conventional and nanotechnology-based strategies to achieve antimicrobial efficacy in dental biomaterials. Recent developments in the design and synthesis of antimicrobial peptides and antifouling zwitterionic polymers to effectively lessen the risks of antimicrobial drug resistance are also outlined in this review. Further, the role of contemporary strategies such as use of smart biomaterials, ionic solvent-based biomaterials and quorum quenchers incorporated biomaterials in the elimination of dental pathogens are described in detail. Lastly, we mentioned the approach of using polymers to print custom-made three-dimensional antibacterial dental products via additive manufacturing technologies. This review provides a critical perspective on the chemical, biomimetic, and engineering strategies intended for developing antimicrobial biomaterials that have the potential to substantially improve the dental health.
Subject(s)
Anti-Infective Agents , Biocompatible Materials , Dental Materials , Oral Health , Animals , Antimicrobial Peptides , Dental Caries/prevention & control , Humans , Mice , Nanostructures , Printing, Three-DimensionalABSTRACT
Brain-Computer Interface (BCI) is an advanced and multidisciplinary active research domain based on neuroscience, signal processing, biomedical sensors, hardware, etc. Since the last decades, several groundbreaking research has been conducted in this domain. Still, no comprehensive review that covers the BCI domain completely has been conducted yet. Hence, a comprehensive overview of the BCI domain is presented in this study. This study covers several applications of BCI and upholds the significance of this domain. Then, each element of BCI systems, including techniques, datasets, feature extraction methods, evaluation measurement matrices, existing BCI algorithms, and classifiers, are explained concisely. In addition, a brief overview of the technologies or hardware, mostly sensors used in BCI, is appended. Finally, the paper investigates several unsolved challenges of the BCI and explains them with possible solutions.
Subject(s)
Brain-Computer Interfaces , Algorithms , Brain , Electroencephalography , Signal Processing, Computer-Assisted , User-Computer InterfaceABSTRACT
Sustainable treatment of wastewater containing trivalent chromium (Cr3+) remains a significant challenge owing to the several limitations of the existing methodologies. Herein, combination of biosynthesis and Response Surface Methodology (RSM) for the fabrication and optimization of Shewanella oneidensis biofilm functionalized graphene-magnetite (GrM) nanobiocomposite was adopted as a 'living functional nanomaterial' (viz. S-GrM) for effective removal of Cr3+ ions from aqueous solution. In the biosynthetic process, S. oneidensis cells reduced the GO-akaganeite complex and adhered on the as-synthesized GrM nanocomposite to form S-GrM hybrid-nanobiocomposite. The process parameters for fabrication of S-GrM hybrid-nanobiocomposite was optimized by RSM based on four responses of easy magnetic separation, biofilm formation along with protein, and carbohydrate contents in extracellular polymeric substances (EPS). The morphology and chemical composition of S-GrM hybrid-nanobiocomposite were investigated using various spectroscopic and microscopic analyses and subsequently explored for removal of Cr3+ ions. The hybrid-nanobiocomposite effectively removed 304.64 ± 14.02 mg/g of Cr3+ at pH 7.0 and 30 °C, which is found to be very high compared to the previously reported values. The high surface area of graphene, biofilm biomass of S. oneidensis and plenty of functional groups provided a unique structure to the S-GrM hybrid-nanobiocomposite for efficient removal of Cr3+ through synergistic interaction. The FTIR and zeta potential studies confirmed that electrostatic and chelation/complexation reaction played key roles in the adsorption process. The fabrication of S-GrM nanobiocomposite thus creates a novel hybrid 'living functional nanomaterial' for low cost, recyclable, and sustainable removal of Cr3+ from wastewater.
Subject(s)
Graphite , Water Pollutants, Chemical , Adsorption , Biofilms , Chromium/analysis , Ferrosoferric Oxide , Hydrogen-Ion Concentration , Shewanella , Water Pollutants, Chemical/analysisABSTRACT
Accidents on battlefields and roads often lead to hemorrhage and uncontrolled bleeding. Hence, immediate hemorrhage control remains of great importance to reduce mortality and socioeconomic loss. Herein, nanobiocomposite scaffolds (film and sponge) have been fabricated for the first time through the incorporation of a graphene-silver-polycationic peptide (GAP) nanocomposite into chitosan (Cs). Ten different scaffolds viz. Cs, Cs-GAP25, Cs-GAP50, Cs-GAP75, and Cs-GAP100 were prepared in the form of films and sponges. Cs-GAP100 nanobiocomposite sponge exhibited excellent porosity, fluid absorption, and blood clotting capacity, whereas Cs-GAP100 nanobiocomposite film showed excellent mechanical strength and poor degradation property. The presence of graphene in GAP provided a unique mechanical property and prevented the natural degradation, whereas silver nanoparticles and polycationic peptide provided an efficient antimicrobial property to the scaffolds. The high surface area of graphene and the hydrophilic nature of the polycationic peptide also imparted high fluid and blood absorption capacity to Cs-GAP nanobiocomposite scaffolds. The in vitro whole blood clotting assay demonstrated that clotting efficacy improved with the concentration of GAP nanocomposite and Cs-GAP100 nanobiocomposite sponge significantly (p value <0.003) reduced the clotting time to 60 s, as compared to the pristine chitosan dressings. On the other side, the Cs-GAP100 nanobiocomposite film showed an excellent wound-healing property. The Cs-GAP100 nanobiocomposite demonstrated profound antibacterial activity against Escherichia coli and Staphylococcus aureus. The intracellular reactive oxygen species (ROS) assay explained the interfacial interaction of Cs-GAP100 nanobiocomposite and bacterial cells, resulting in cell damage and finally cell death. The obtained information thus provided a novel safe-by-design concept for fabrication of Cs-GAP100 nanobiocomposite scaffolds and demonstrated potential development of antibacterial hemostatic and wound dressing in traumacare management.
Subject(s)
Anti-Infective Agents , Chitosan , Graphite , Metal Nanoparticles , Nanocomposites , Anti-Bacterial Agents/pharmacology , Hemorrhage , Humans , SilverABSTRACT
An innovative fluorescein appended naphthalene diimide based probe (FANDI) has been prepared and characterized to selectively recognize hypochlorite or ClO- ions in the presence of other reactive oxygen species (ROS) and biorelevant ions, using a unique chemodosimetric method. Hypochlorite induced oxidation can efficiently alter the initial photophysical properties of FANDI and shows an easily detectable "turn on" green fluorescence. The chemodosimeter FANDI can efficiently detect exogenous as well as endogenous ClO- ions in RAW 264.7 cells (macrophages) and zebrafish embryos (Danio rerio) which further ensures the high potential, easy cell permeability and photostability of FANDI and makes it worth exploring in the future.
Subject(s)
Hypochlorous AcidABSTRACT
Recently, there is incredible growth on optoelectronic properties of new supramolecular gels and white-light-emitting (WLE) metalo-organic gel comprised with single lanthanide metal ion having stimuli-responsive property is not yet reported. Here, we report a mandelic acid (MA)-triethylene tetraamine (TETA)-Eu-acetate conjugate (4.5:1:0.4 mol ratio), producing stimuli-sensitive WLE hydrogel exhibiting thermoreversible, thixotropic, pH-switchable, self-standing and self-healing properties. Energy minimized structure suggests complexation between MA-TETA conjugate and Eu3+ ion. Fluorescence intensity of MA-TETA conjugate decreases with increasing Eu3+ concentration indicating energy transfer from MA-TETA to Eu3+. Decay of donor fluorescence intensity follows Stern-Volmer equation and energy transfer efficiency is 42%. WLE gel has Quantum yield 11.4% and Förster distance 1.7 Å. Hydrogel and xerogel show WLE on excitation at 330 and 350 nm having CIE coordinates (0.34, 0.33) and (0.28, 0.32), respectively. WLE gel has Correlated colour temperature 5148 K, appropriate for cool day light emission and on coating over UV-LED bulb it emits bright white light.
ABSTRACT
A Kashmir Himalayan (India) soil isolate, Streptomyces sp. SM01 was subjected to small scale fermentation for the production of novel antimicrobials, picolinamycin (SM1). The production has been optimized which found to be maximum while incubated in AIA medium (pH 7) for 7 days at 30 °C. Seven days grew crude cell-free culture media (50 µL) showed a larger zone of inhibition against Staphylococcus aureus compared to streptomycin (5 µg) and ampicillin (5 µg). Extraction, purification, and chemical analysis of the antimicrobial component has been proved to be a new class of antibiotic with 1013 dalton molecular weight. We have named this new antibiotic as picolinamycin for consisting picolinamide moiety in the center of the molecule and produced by a Streptomyces sp. In general, the antimicrobial potency of this newly characterized antibiotic found to be higher against Gram-positive organisms than the tested Gram-negative organisms. The MIC of this antimicrobial compound was found to be 0.01 µg/ml for tested Gram-positive organisms and 0.02 to 5.12 µg/ml for Gram-negative organisms. Furthermore, it showed strong growth impairments of several multidrug resistance (MDR) strains, including methicillin-resistant strains of Staphylococci and Enterococci with the MIC value of 0.04 to 5.12 µg/ml and MDR (but methicillin-sensitive) strains of S. aureus with the MIC value of 0.084 µg/ml. It also showed anti-mycobacterial potential in higher concentrations (MIC is 10.24 µg/ml). Picolinamycin however did not show toxicity against tested A549 human cell line indicating that the spectrum of its activity limited within bacteria only.
Subject(s)
Drug Resistance, Multiple/drug effects , Streptomyces/metabolism , Streptomycin/pharmacology , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Enterococcus/drug effects , India , Microbial Sensitivity Tests , Soil/chemistry , Soil Microbiology , Staphylococcus/drug effects , Staphylococcus aureus/drug effects , Streptomyces/chemistryABSTRACT
In this review, we focus on the very recent developments on the use of the stimuli responsive properties of polymer hydrogels for targeted drug delivery, tissue engineering, and biosensing utilizing their different optoelectronic properties. Besides, the stimuli-responsive hydrogels, the conducting polymer hydrogels are discussed, with specific attention to the energy generation and storage behavior of the xerogel derived from the hydrogel. The electronic and ionic conducting gels have been discussed that have applications in various electronic devices, e.g., organic field effect transistors, soft robotics, ionic skins, and sensors. The properties of polymer hybrid gels containing carbon nanomaterials have been exemplified here giving attention to applications in supercapacitors, dye sensitized solar cells, photocurrent switching, etc. Recent trends in the properties and applications of some natural polymer gels to produce thermal and acoustic insulating materials, drug delivery vehicles, self-healing material, tissue engineering, etc., are discussed. Besides the polymer gels, peptide gels of different dipeptides, tripeptides, oligopeptides, polypeptides, cyclic peptides, etc., are discussed, giving attention mainly to biosensing, bioimaging, and drug delivery applications. The properties of peptide-based hybrid hydrogels with polymers, nanoparticles, nucleotides, fullerene, etc., are discussed, giving specific attention to drug delivery, cell culture, bio-sensing, and bioimaging properties. Thus, the present review delineates, in short, the preparation, properties, and applications of different polymer and peptide hydrogels prepared in the past few years.