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1.
Brain ; 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864500

RESUMO

The fate of deprived sensory cortices - visual regions in the blind and auditory regions in the deaf - exemplifies the extent to which experience can change brain regions. These regions are frequently seen to activate during tasks involving other sensory modalities, leading many accounts to infer that these regions have started processing sensory information of other modalities. However, such observations can also imply that these regions are now activating to any task event regardless of the sensory modality. Activating to task events, irrespective of the sensory modality involved, is a feature of the multiple-demands (MD) network. These are a common set of regions within the frontal and parietal cortices that activate in response to any kind of control demand. Thus, demands as diverse as attention, perceptual difficulty, rule-switching, updating working memory, inhibiting responses, decision-making, and difficult arithmetic - all activate these same set of regions that are thought to instantiate domain-general cognitive control and underpin fluid intelligence. We investigated if deprived sensory cortices, or foci within them, become part of the MD network. We tested if the same foci within the visual regions of the blind and auditory regions of the deaf activated to different control demands. We found that control demands related to updating auditory working memory, difficult tactile decisions, time-duration judgments, and sensorimotor-speed - all activated the entire bilateral occipital regions in the blind but not in the sighted. These occipital regions in the blind were the only regions outside the canonical fronto-parietal MD regions to show such activation to multiple control demands. Further, compared to the sighted, these occipital regions in the blind had higher functional connectivity with fronto-parietal MD regions. Early deaf, in contrast, did not activate their auditory regions to different control demands, showing that auditory regions do not become MD regions in the deaf. We suggest that visual regions in the blind do not take a new sensory role but become part of the MD network, and this is not a response of all deprived sensory cortices but a feature unique to the visual regions.

2.
Environ Monit Assess ; 190(3): 139, 2018 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-29442190

RESUMO

Influence of open dumping of municipal solid wastes (MSW) on metal contamination of soil, plants, and earthworms in Ranchi, Jharkhand, India, was studied over 6-month period. Dumpsite in the study area exists in two sections, old section where waste dumping has stopped and new section where wastes are currently disposed. Soil around dumpsite had high concentration of Co, Cr, Cu, Pb, and Zn than that at control site. Geoaccumulation index indicated uncontaminated to moderate level of soil contamination at old dumpsite and soil at new dumpsite was found to be uncontaminated. Parthenium hysterophorus, Lantana camara, and Calotropis procera were the main plants found in patchy distribution around dumpsite. Plants exhibited almost similar levels of metal concentration in roots and shoots. P. hysterophorus and L. camara showed high bioaccumulation capacity and low translocation capacity. C. procera showed moderate bioaccumulation capacity and high translocation capacity as the concentration of metals was higher in the shoot. P. hysterophorus and L. camara due to higher bioaccumulation capacity and lower translocation capacity appear to be suitable for phytostabilization of metal-contaminated soil. Earthworms present at the dumpsite showed high concentration of Cr, Cu, Pb, and Zn with bioconcentration factor > 1. Results highlights that soil contamination due to metals is occurring at the dumpsite which is also leading to transfer of metals to plants and earthworms which can pose serious risk to environment and human health. The plants identified can be used for decontamination of metals from the dumpsite.


Assuntos
Monitoramento Ambiental , Metais/análise , Eliminação de Resíduos/métodos , Poluentes do Solo/análise , Resíduos Sólidos/análise , Animais , Humanos , Índia , Lantana , Metais/toxicidade , Metais Pesados/análise , Oligoquetos/fisiologia , Raízes de Plantas/química , Plantas , Solo
3.
ACS Appl Bio Mater ; 7(6): 3649-3659, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38728425

RESUMO

Recently, different alternative regulated cell death (RCD) pathways, viz., necroptosis, pyroptosis, ferroptosis, cuproptosis etc., have been explored as important targets for the development of cancer medications in recent years, as these can change the immunogenicity of the tumor microenvironment (TME) and will finally lead to the inhibition of cancer progression and metastasis. Here, we report the development of transferrin immobilized graphene oxide (Tfn@GOAPTES) nanocomposite as a therapeutic strategy toward cancer cell killing. The electrostatic immobilization of Tfn on the GOAPTES surface was confirmed by different spectroscopy and microscopy techniques. The Tfn immobilization was found to be ∼74 ± 4%, whereas the stability of the protein on the GO surface suggested a robust nature of the nanocomposite. The MTT assay suggested that Tfn@GOAPTES exhibited cytotoxicity toward HeLa cells via increased lipid peroxidation and DNA damage. Western blot studies resulted in decreased expression of acetylation on lysine 40 of α-tubulin and increased expression of LC3a/b for Tfn@GOAPTES treated HeLa cells, suggesting autophagy to be the main cause of the cell death mechanism. Overall, we predict that the present approach can be used as a therapeutic strategy for cancer cell killing via selective induction of a high concentration of intracellular iron.


Assuntos
Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Grafite , Nanocompostos , Transferrina , Grafite/química , Grafite/farmacologia , Humanos , Nanocompostos/química , Transferrina/química , Transferrina/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Células HeLa , Tamanho da Partícula , Teste de Materiais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Ferro/química , Ferro/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos
4.
ACS Appl Mater Interfaces ; 15(50): 58212-58229, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38060572

RESUMO

The emergence of various lethal bacterial infections and their adherence to medical devices are major public health concerns. The increased bacterial exposure and titer are accompanied by the inappropriate use of antibiotics that sometimes lead to antibiotic resistance, and therefore, a drug-free antibacterial approach is required. Several nanoparticles (NPs) have been developed as antibacterial and antibiofilm coating agents, which can overcome different drug resistance mechanisms by inhibiting the important processes related to bacterial virulence potential. However, developing safe and biocompatible nanomaterials (NMs) for these applications has remained a major challenge due to their poorly understood mechanism of action. In this work, biogenic silica NPs were modified with glutathione (GSH) to form GSH@SNP (∼80 ± 15 nm) for targeting the bacterial cell surface and biofilm. GSH@SNP was loaded with resveratrol to obtain Res_GSH@SNP (∼124 ± 15 nm) that enhances the antibacterial activity of the NPs against Staphylococcus aureus and Escherichia coli by ∼51 and ∼49%, respectively, compared to GSH@SNP. Res_GSH@SNP is responsible for binding to the bacterial cell surface receptors that interrupt the cell membrane potential, leading to reactive oxygen species (ROS) generation, membrane disruption, and DNA damage and eventually resulting in antibacterial activity. Moreover, the antibiofilm activity of Res_GSH@SNP has been found to result from the interaction of the NPs with the abundant carbohydrates present on the biofilm surface. To check the practical utility of Res_GSH@SNP, these were further evaluated as an antibacterial and antibiofilm coating agent for urinary catheters and were found to be effective even after multiple washes. Res_GSH@SNP has been found to exhibit ∼80 ± 1.4% cytocompatibility toward fibroblast NIH-3T3 cells. Overall, this study is expected to pave the way for the development of biocompatible NP-based coating agents for medical devices.


Assuntos
Nanopartículas , Dióxido de Silício , Animais , Camundongos , Resveratrol/farmacologia , Dióxido de Silício/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas/química , Biofilmes , Glutationa/farmacologia , Testes de Sensibilidade Microbiana
5.
ACS Appl Mater Interfaces ; 15(39): 45585-45600, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37737830

RESUMO

Due to impaired wound healing, millions of acute and chronic wound cases with increased morbidity have been recorded in the developed countries. The primary reason has been attributed to uncontrolled inflammation at the wound site, which makes healing impossible for years. The use of red blood cell (RBC) ghosts or erythrocyte membranes for different theranostic applications has gained significant attention in recent years due to their biocompatibility and biomimicking properties. Our study builds upon this concept by presenting a new approach for creating an improved and controlled inflammatory response by employing RBC ghost encapsulated tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) modified AuNPs (gold nanoparticles) for accelerating the wound healing at early postinjury stage (∼48 h). The results suggested that the developed GTNFα-IL6@AuNPs created a controlled and time dependent TNF-α response and showed increased reactive oxygen species generation at ∼12 h. Further, proper M1/M2 functional transition of macrophages was observed in macrophages at different time intervals. The expression results suggested that the levels of wound healing biomarkers like transforming growth factor-ß (1.8-fold) and collagen (2.4-fold) increased while matrix metalloproteinase (3-8-fold) levels declined at later stages, which possibly increased the cell migration rate of NP treated cells to ∼90%. Hence, we are here reducing the timeline of the inflammatory phase of wound healing by actually creating a controlled inflammatory response at an early postinjury stage and further assisting in regaining the ability of cells for wound remodelation and repair. We intend that this new approach has the potential to improve the current treatment strategies for wound healing and skin repair under both in vitro and in vivo conditions.

6.
Colloids Surf B Biointerfaces ; 232: 113583, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37844474

RESUMO

Infectious diseases resulting from the high pathogenic potential of several bacteria possesses a major threat to human health and safety. Traditional methods used for screening of these microorganisms face major issues with respect to detection time, selectivity and specificity which may delay treatment for critically ill patients past the optimal time. Thus, a convincing and essential need exists to upgrade the existing methodologies for the fast detection of bacteria. In this context, increasing number of newly emerging nanomaterials (NMs) have been discovered for their effective use and applications in the area of diagnosis in bacterial infections. Recently, functional fluorescent nanomaterials (FNMs) are extensively explored in the field of biomedical research, particularly in developing new diagnostic tools, nanosensors, specific imaging modalities and targeted drug delivery systems for bacterial infection. It is interesting to note that organic fluorophores and fluorescent proteins have played vital role for imaging and sensing technologies for long, however, off lately fluorescent nanomaterials are increasingly replacing these due to the latter's unprecedented fluorescence brightness, stability in the biological environment, high quantum yield along with high sensitivity due to enhanced surface property etc. Again, taking advantage of their photo-excitation property, these can also be used for either photothermal and photodynamic therapy to eradicate bacterial infection and biofilm formation. Here, in this review, we have paid particular attention on summarizing literature reports on FNMs which includes studies detailing fluorescence-based bacterial detection methodologies, antibacterial and antibiofilm applications of the same. It is expected that the present review will attract the attention of the researchers working in this field to develop new engineered FNMs for the comprehensive diagnosis and treatment of bacterial infection and biofilm formation.


Assuntos
Infecções Bacterianas , Nanoestruturas , Humanos , Nanoestruturas/uso terapêutico , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/tratamento farmacológico , Diagnóstico por Imagem/métodos , Corantes Fluorescentes , Bactérias , Biofilmes
7.
Nanoscale ; 14(32): 11635-11654, 2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-35904404

RESUMO

In this report, biogenic, crystalline (∼60.5 ± 2%) bowknot structured silica nanoparticles (BSNPs) of length ∼ 274 ± 7 nm and width ∼ 36 ± 2 nm were isolated from invasive species viz. Lantana camara. These were then chemically modified using nitrogen containing moieties viz. APTES and CTAB. These modified BSNPs were then used as electrostatic cross-linking agents for the formation of tragacanth gum (TG) hydrogels. The cytocompatible CTAB@BSNP-TG hydrogels documented ∼10-12 fold enhancement in anti-bacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa when compared with TG hydrogels. Disruption of the bacterial membrane by ROS generation and protein leakage were responsible for anti-bacterial activity. A cell migration assay suggested that CTAB@BSNP-TG augmented the cell proliferation of NIH-3T3 cells compared to other TG hydrogels. The present study will pave the path for the development of organic-inorganic hybrid nanocomposite-based hydrogels for anti-bacterial and cell migration applications.


Assuntos
Nanopartículas , Tragacanto , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Cetrimônio , Hidrogéis/química , Hidrogéis/farmacologia , Camundongos , Dióxido de Silício , Tragacanto/química
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