Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
PLoS Pathog ; 19(1): e1011117, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36719928

RESUMO

Aedes aegypti mosquitoes carrying self-spreading, virus-blocking Wolbachia bacteria are being deployed to suppress dengue transmission. However, there are challenges in applying this technology in extreme environments. We introduced two Wolbachia strains into Ae. aegypti from Saudi Arabia for a release program in the hot coastal city of Jeddah. Wolbachia reduced infection and dissemination of dengue virus (DENV2) in Saudi Arabian mosquitoes and showed complete maternal transmission and cytoplasmic incompatibility. Wolbachia reduced egg hatch under a range of environmental conditions, with the Wolbachia strains showing differential thermal stability. Wolbachia effects were similar across mosquito genetic backgrounds but we found evidence of local adaptation, with Saudi Arabian mosquitoes having lower egg viability but higher adult desiccation tolerance than Australian mosquitoes. Genetic background effects will influence Wolbachia invasion dynamics, reinforcing the need to use local genotypes for mosquito release programs, particularly in extreme environments like Jeddah. Our comprehensive characterization of Wolbachia strains provides a foundation for Wolbachia-based disease interventions in harsh climates.


Assuntos
Aedes , Dengue , Wolbachia , Animais , Arábia Saudita , Austrália , Ambientes Extremos
2.
iScience ; 25(11): 105344, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36325069

RESUMO

At nanoconfined interfaces, a micellar ink of lipids was programmed to transform into various secondary structures such as discs, sheets, or sheet and discs via patterning-mediated self-assembly facilitated by polymer pen lithography. Nanoconfinement with printing force, humidity, temperature, pattern size, and total printing time all governed the intramolecular assembly of lipids and determined their structural shape and size. For example, disc or sheet architectures self-organized to produce cochleates or discotic liquid crystals, respectively. In contrast, the combined structure of sheet and discs produced a novel supramolecular output referred to as "nanopalms". The mechanism of nanopalms formation and the origin of their stability were investigated and discussed. Post patterning treatment helped to transform the patterned discs into ribbons and sheets into cochleates that could facilitate the curling of ribbons along their folding direction in a programmed manner via intermolecular self-organization producing the nanopalms.

3.
Insects ; 13(10)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36292897

RESUMO

Releases of Aedes aegypti carrying Wolbachia bacteria are known to suppress arbovirus transmission and reduce the incidence of vector-borne diseases. In planning for Wolbachia releases in the arid environment of Jeddah, Saudi Arabia, we collected entomological data with ovitraps across a 7-month period in four locations. Herein, we show that mosquito presence in basements does not differ from that of non-basement areas of buildings. In modelling mosquito presence across the study sites, we found the spatial structure to be statistically significant in one of the four sites, while a significant spatial structure was found for egg production data across three of the four sites. The length scales of the spatial covariance functions fitted to the egg production data ranged from 143 m to 574 m, indicating that high productivity regions can be extensive in size. Rank-correlation analyses indicated that mosquito presence tended to persist from the dry to wet season, but that egg production ranks at locations could reverse. The data suggest that, in Jeddah, the quality of the local environment for breeding can vary over time. The data support the feasibility of dry season releases but with release numbers needing to be flexible depending on local rates of invasion.

4.
Nanoscale Adv ; 4(5): 1336-1344, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36133681

RESUMO

Oxidative chemical etching of metal nanoparticles (NPs) to produce holey graphene (hG) suffers from the presence of aggregated NPs on the graphene surface triggering heterogeneous etching rates and thereby producing irregular sized holes. To encounter such a challenge, we investigated the use of scanning probe block co-polymer lithography (SPBCL) to fabricate precisely positioned silver nanoparticles (AgNPs) on graphene surfaces with exquisite control over the NP size to prevent their aggregation and consequently produce uniformly distributed holes after oxidative chemical etching. SPBCL experiments were carried out via printing an ink suspension consisting of poly(ethylene oxide-b-2-vinylpyridine) and silver nitrate on a graphene surface in a selected pattern under controlled environmental and instrumental parameters followed by thermal annealing in a gaseous environment to fabricate AgNPs. Scanning electron microscopy revealed the uniform size distribution of AgNPs on the graphene surface with minimal to no aggregation. Four main sizes of AgNPs were obtained (37 ± 3, 45 ± 3, 54 ± 2, and 64 ± 3 nm) via controlling the printing force, z-piezo extension, and dwell time. Energy dispersive X-ray spectroscopy analysis validated the existence of elemental Ag on the graphene surface. Subsequent chemical etching of AgNPs using nitric acid (HNO3) with the aid of sonication and mechanical agitation produced holes of uniform size distribution generating hG. The obtained I D/I G ratios ≤ 0.96 measured by Raman spectroscopy were lower than those commonly reported for GO (I D/I G > 1), indicating the removal of more defective C atoms during the etching process to produce hG while preserving the remaining C atoms in ordered or crystalline structures. Indeed, SPBCL could be utilized to fabricate uniformly distributed AgNPs of controlled sizes on graphene surfaces to ultimately produce hG of uniform hole size distribution.

5.
Biomedicines ; 10(2)2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35203623

RESUMO

Robust inflammation-suppressing nanoparticles based on α1-acid glycoprotein (AGP)-conjugated hyaluronic acid nanoparticles (AGP-HA NPs) were designed to regulate breast cancer cells' sensitivity to chemotherapy and to suppress tumor metastasis. The successful conjugation between AGP and HA NPs was confirmed using FTIR, zeta potential, and UV-vis spectroscopy. In vitro studies on MCF-7 cells indicated the remarkable ability of AGP-HA NPs in suppressing migratory tumor ability by 79% after 24 h. Moreover, the efficacy study showed the high capability of AGP-HA NPs in modulating MDA-MB-231 cells and restoring cell sensitivity to the chemotherapeutic drug doxorubicin (DOX). Furthermore, the finding obtained by flow cytometry and confocal spectroscopy demonstrated that AGP-HA NPs enhanced DOX uptake/retention and aided it to reach cell nucleus within 4 h of incubation. Therefore, AGP-HA NPs represent a viable and effective treatment option to strengthen the anticancer effects of chemotherapeutic agents and potentially improve patients' survival rates.

6.
Saudi Pharm J ; 30(1): 28-38, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35145343

RESUMO

Local production of pharmaceuticals plays a vital role in maintaining resilience of national healthcare systems, especially when it comes to facilitating access to needed medicines and decreasing exposure to imports and international supply chains. Pharma is a research-intensive industry and the systemic lack of governance and support to R&D activities in this sector, among other host of related issues such as unsupportive regulatory regimes and human resources capacity limitations, is one of the major impediments to the diversifying of locally produced pharmaceuticals portfolio. In this review, an overview of the current pharmaceutical production system in Saudi Arabia, its major challenges, and proposed remedies to address them will be highlighted.

7.
Immunotherapy ; 13(14): 1215-1229, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34498496

RESUMO

Over recent years, tremendous advances in immunotherapy approaches have been observed, generating significant clinical progress. Cancer immunotherapy has been shown, in different types of blood cancers, to improve the overall survival of patients. Immunotherapy treatment of hematopoietic malignancies is a newly growing field that has been accelerating over the past years. Several US FDA approved drugs and cell-based therapies are being exploited in the late stage of clinical trials. This review attempt to highlight and discuss the numerous innovative immunotherapy approaches of hematopoietic malignancy ranging from nonmyeloablative transplantation, T-cell immunotherapy, natural killer cells and immune agonist to monoclonal antibodies and vaccination. In addition, a brief discussion on the future advances and accomplishments required to counterpart the current immunotherapeutic approaches for hematopoietic malignancies were also highlighted.


Assuntos
Neoplasias Hematológicas/terapia , Imunoterapia/métodos , Imunoterapia/tendências , Humanos
8.
Cancers (Basel) ; 13(12)2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-34203051

RESUMO

High-grade serous ovarian cancer (HGSOC) is the most lethal gynecological malignancy among women. Several obstacles impede the early diagnosis and effective treatment options for ovarian cancer (OC) patients, which most importantly include the development of platinum-drug-resistant strains. Currently, extensive efforts are being put into the development of strategies capable of effectively circumventing the physical and biological barriers present in the peritoneal cavity of metastatic OC patients, representing a late stage of gastrointestinal and gynecological cancer with an extremely poor prognosis. Naturally occurring extracellular vesicles (EVs) have been shown to play a pivotal role in progression of OC and are now being harnessed as a delivery vehicle for cancer chemotherapeutics. However, there are limitations to their clinical application due to current challenges in their preparation techniques. Intriguingly, there is a recent drive towards the use of engineered synthetic EVs for the delivery of chemotherapeutics and RNA interference therapy (RNAi), as they show the promise of overcoming the obstacles in the treatment of OC patients. This review discusses the therapeutic application of EVs in OC and elucidates the potential use of engineered EV-mimetic nanoparticles as a delivery vehicle for RNAi therapy and other chemotherapeutics, which would potentially improve clinical outcomes of OC patients.

9.
Molecules ; 26(9)2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-34064416

RESUMO

The objective of this study was to synthesize and characterize a set of biodegradable block copolymers based on TPGS-block-poly(ε-caprolactone) (TPGS-b-PCL) and to assess their self-assembled structures as a nanodelivery system for paclitaxel (PAX). The conjugation of PCL to TPGS was hypothesized to increase the stability and the drug solubilization characteristics of TPGS micelles. TPGS-b-PCL copolymer with various PCL/TPGS ratios were synthesized via ring opening bulk polymerization of ε-caprolactone using TPGS, with different molecular weights of PEG (1-5 kDa), as initiators and stannous octoate as a catalyst. The synthesized copolymers were characterized using 1H NMR, GPC, FTIR, XRD, and DSC. Assembly of block copolymers was achieved via the cosolvent evaporation method. The self-assembled structures were characterized for their size, polydispersity, and CMC using dynamic light scattering (DLS) technique. The results from the spectroscopic and thermal analyses confirmed the successful synthesis of the copolymers. Only copolymers that consisted of TPGS with PEG molecular weights ≥ 2000 Da were able to self-assemble and form nanocarriers of ≤200 nm in diameter. Moreover, TPGS2000-b-PCL4000, TPGS3500-b-PCL7000, and TPGS5000-b-PCL15000 micelles enhanced the aqueous solubility of PAX from 0.3 µg/mL up to 88.4 ug/mL in TPGS5000-b-PCL15000. Of the abovementioned micellar formulations, TPGS5000-b-PCL15000 showed the slowest in vitro release of PAX. Specifically, the PAX-loaded TPGS5000-b-PCL15000 micellar formulation showed less than 10% drug release within the first 12 h, and around 36% cumulative drug release within 72 h compared to 61% and 100% PAX release, respectively, from the commercially available formulation (Ebetaxel®) at the same time points. Our results point to a great potential for TPGS-b-PCL micelles to efficiently solubilize and control the release of PAX.


Assuntos
Portadores de Fármacos/química , Nanopartículas/química , Paclitaxel/farmacologia , Poliésteres/química , Vitamina E/química , Varredura Diferencial de Calorimetria , Cromatografia em Gel , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Micelas , Nanopartículas/ultraestrutura , Tamanho da Partícula , Poliésteres/síntese química , Espectroscopia de Prótons por Ressonância Magnética , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vitamina E/síntese química , Água/química , Difração de Raios X
10.
J Clin Invest ; 131(14)2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34043590

RESUMO

A recent report found that rare predicted loss-of-function (pLOF) variants across 13 candidate genes in TLR3- and IRF7-dependent type I IFN pathways explain up to 3.5% of severe COVID-19 cases. We performed whole-exome or whole-genome sequencing of 1,864 COVID-19 cases (713 with severe and 1,151 with mild disease) and 15,033 ancestry-matched population controls across 4 independent COVID-19 biobanks. We tested whether rare pLOF variants in these 13 genes were associated with severe COVID-19. We identified only 1 rare pLOF mutation across these genes among 713 cases with severe COVID-19 and observed no enrichment of pLOFs in severe cases compared to population controls or mild COVID-19 cases. We found no evidence of association of rare LOF variants in the 13 candidate genes with severe COVID-19 outcomes.


Assuntos
COVID-19/genética , COVID-19/imunologia , Interferon Tipo I/genética , Interferon Tipo I/imunologia , Mutação com Perda de Função , SARS-CoV-2 , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Lactente , Recém-Nascido , Fator Regulador 7 de Interferon/genética , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Receptor 3 Toll-Like/genética , Sequenciamento do Exoma , Sequenciamento Completo do Genoma , Adulto Jovem
11.
Polymers (Basel) ; 13(8)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918625

RESUMO

Epirubicin (EPI) is an anti-cancerous chemotherapeutic drug that is an effective epimer of doxorubicin with less cardiotoxicity. Although EPI has fewer side effects than its analog, doxorubicin, this study aims to develop EPI nanoparticles as an improved formula of the conventional treatment of EPI in its free form. METHODS: In this study, EPI-loaded polymeric nanoparticles (EPI-NPs) were prepared by the double emulsion method using a biocompatible poly (lactide) poly (ethylene glycol) poly(lactide) (PLA-PEG-PLA) polymer. The physicochemical properties of the EPI-NPs were determined by dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), entrapment efficiency and stability studies. The effect of EPI-NPs on cancer cells was determined by high throughput imaging and flow cytometry. RESULTS: The synthesis process resulted in monodisperse EPI-NPs with a size of 166.93 ± 1.40 nm and an elevated encapsulation efficiency (EE) of 88.3%. In addition, TEM images revealed the spherical uniformness of EPI-NPs with no aggregation, while the cellular studies presented the effect of EPI-NPs on MCF-7 cells' viability; after 96 h of treatment, the MCF-7 cells presented considerable apoptotic activity. The stability study showed that the EPI-NPs remained stable at room temperature at physiological pH for over 30 days. CONCLUSION: EPI-NPs were successfully encapsulated within a highly stable biocompatible polymer with minimal loss of the drug. The used polymer has low cytotoxicity and EPI-NPs induced apoptosis in estrogen-positive cell line, making them a promising, safe treatment for cancer with less adverse side effects.

12.
Biomater Sci ; 9(11): 3898-3910, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-33912874

RESUMO

Repetitive outbreaks and prolonged epidemics represent mortal threats to global health, creating chaos in our globalized world. To date, scientists have been compelled to follow FDA guidelines for conventional clinical trials, which decelerates the release of effective therapies to battle outbreaks and safeguard global health security. Developing multi-purpose platform nanotechnologies to self-target specific organs in response to the disease microenvironment could greatly help to rapidly anticipate and efficiently manage outbreaks. Nano-interventions in the form of self-targeting nanoparticles (NPs) could accelerate the clinical translation of potential drugs to fight future outbreaks via innovating their clinical trials. This review sets the foundation of the self-targeting concept to govern the in vivo fate of NPs without the need to complicate the engineering designs with targeting ligands. The proposed catalogue of accelerated nano-innovations offers self-targeting, physiological trafficking, bio-compliance, and controllable drug release in response to associated smart linkers.


Assuntos
Invenções , Nanopartículas , Liberação Controlada de Fármacos , Nanotecnologia
13.
Sci Adv ; 7(4)2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33523955

RESUMO

The major impediments to the implementation of cancer immunotherapies are the sustained immune effect and the targeted delivery of these therapeutics, as they have life-threatening adverse effects. In this work, biomimetic metal-organic frameworks [zeolitic imidazolate frameworks (ZIFs)] are used for the controlled delivery of nivolumab (NV), a monoclonal antibody checkpoint inhibitor that was U.S. Food and Drug Administration-approved back in 2014. The sustained release behavior of NV-ZIF has shown a higher efficacy than the naked NV to activate T cells in hematological malignancies. The system was further modified by coating NV-ZIF with cancer cell membrane to enable tumor-specific targeted delivery while treating solid tumors. We envisage that such a biocompatible and biodegradable immunotherapeutic delivery system may promote the development and the translation of hybrid superstructures into smart and personalized delivery platforms.


Assuntos
Estruturas Metalorgânicas , Neoplasias , Zeolitas , Biomimética , Humanos , Imunoterapia , Estruturas Metalorgânicas/química , Neoplasias/tratamento farmacológico , Estados Unidos , Zeolitas/química
14.
Environ Sci Pollut Res Int ; 28(6): 7379-7389, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33030691

RESUMO

Metal nanomaterials such as bismuth oxide nanoparticles (Bi2O3NPs) have been extensively used in cosmetics, dental materials, pulp capping, and biomedical imaging. There is little knowledge about the health risk of Bi2O3NPs in humans, which warrants a thorough toxicity investigation of Bi2O3NPs at the cellular level. In this experiment, we investigated the cytotoxic effect of Bi2O3NPs on human breast cancer (MCF-7) cells over 24 and 48 h. MCF-7 cells were exposed to Bi2O3NPs at varying doses (0.1, 0.5, 1.0, 5, 10, 20, 40 µg/mL) for 24 and 48 h. We assessed the toxicity of Bi2O3NPs by measuring its effect on the viability and oxidative stress biomarkers, e.g., GSH, SOD, and catalase in MCF-7 cells. The pro-apoptotic effects of Bi2O3NPs on MCF-7 cells were determined via evaluating dysfunction of mitochondrial membrane potential (MMP), caspase-3 activity, externalization of phosphatidylserine, and chromosome condensation. Furthermore, apoptotic cells were evaluated using 7-AAD fluorescence stain and Annexin V-FITC. Bi2O3NPs induced oxidative stress in MCF-7 cells in a time- and dose-dependent manner. Bi2O3NPs increased the rate of both necrotic cells and apoptotic cells. In addition, the blue fluorescence of MCF-7 cells with condensed chromatin was increased in a time- and dose-dependent manner. In conclusion, the present study highlights the potential toxic effects of Bi2O3NPs at the cellular level and suggests further investigation of Bi2O3NPs before any medical purposes.


Assuntos
Neoplasias da Mama , Nanopartículas , Apoptose , Bismuto , Humanos , Células MCF-7 , Estresse Oxidativo , Espécies Reativas de Oxigênio
15.
Sci Adv ; 6(30): eaba6884, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32832666

RESUMO

More than 1050 clinical trials are registered at FDA.gov that explore multipotent mesenchymal stromal cells (MSCs) for nearly every clinical application imaginable, including neurodegenerative and cardiac disorders, perianal fistulas, graft-versus-host disease, COVID-19, and cancer. Several companies have or are in the process of commercializing MSC-based therapies. However, most of the clinical-stage MSC therapies have been unable to meet primary efficacy end points. The innate therapeutic functions of MSCs administered to humans are not as robust as demonstrated in preclinical studies, and in general, the translation of cell-based therapy is impaired by a myriad of steps that introduce heterogeneity. In this review, we discuss the major clinical challenges with MSC therapies, the details of these challenges, and the potential bioengineering approaches that leverage the unique biology of MSCs to overcome the challenges and achieve more potent and versatile therapies.


Assuntos
Betacoronavirus , Infecções por Coronavirus/terapia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/metabolismo , Pneumonia Viral/terapia , Técnicas de Cultura Celular por Lotes/métodos , Reatores Biológicos , COVID-19 , Infecções por Coronavirus/virologia , Doença Enxerto-Hospedeiro/terapia , Humanos , Engenharia Metabólica/métodos , Pandemias , Pneumonia Viral/virologia , SARS-CoV-2 , Transplantados
16.
Pharmaceutics ; 12(7)2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679809

RESUMO

PURPOSE: The aim of this work is to optimize a polyethylene glycolated (PEGylated) polymer-lipid hybrid nanoparticulate system for the delivery of anastrozole (ANS) to enhance its biopharmaceutical attributes and overall efficacy. METHODS: ANS loaded PEGylated polymer-lipid hybrid nanoparticles (PLNPs) were prepared by a direct emulsification solvent evaporation method. The physical incorporation of PEG was optimized using variable ratios. The produced particles were evaluated to discern their particle size and shape, zeta-potential, entrapment efficiency, and physical stability. The drug-release profiles were studied, and the kinetic model was analyzed. The anticancer activity of the ANS PLNPs on estrogen-positive breast cancer cell lines was determined using flow cytometry. RESULTS: The prepared ANS-PLNPs showed particle sizes in the range of 193.6 ± 2.9 to 218.2 ± 1.9 nm, with good particle size uniformity (i.e., poly-dispersity index of around 0.1). Furthermore, they exhibited relatively low zeta-potential values ranging from -0.50 ± 0.52 to 6.01 ± 4.74. The transmission electron microscopy images showed spherical shape of ANS-PLNPs and the compliance with the sizes were revealed by light scattering. The differential scanning calorimetry DSC patterns of the ANS PLNPs revealed a disappearance of the characteristic sharp melting peak of pure ANS, supporting the incorporation of the drug into the polymeric matrices of the nanoparticles. Flow cytometry showed the apoptosis of MCF-7 cell lines in the presence of ANS-PLNPs. CONCLUSION: PEGylated polymeric nanoparticles presented a stable encapsulated system with which to incorporate an anticancer drug (ANS) with a high percentage of entrapment efficiency (around 80%), good size uniformity, and induction of apoptosis in MCF-7 cells.

17.
Cryobiology ; 94: 107-115, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32259523

RESUMO

Chinese hamster ovary (CHO) cell lines are the most widely used in vitro cells for research and production of recombinant proteins such as rhGH, tPA, and erythropoietin. We aimed to investigate changes in protein profiles after cryopreservation using 2D-DIGE MALDI-TOF MS and network pathway analysis. The proteome changes that occur in CHO cells between freshly prepared cells and cryopreserved cells with and without Me2SO were compared to determine the key proteins and pathways altered during recovery from cryopreservation. A total of 54 proteins were identified and successfully matched to 37 peptide mass fingerprints (PMF). 14 protein spots showed an increase while 23 showed decrease abundance in the Me2SO free group compared to the control. The proteins with increased abundance included vimentin, heat shock protein 60 kDa, mitochondrial, heat shock 70 kDa protein 9, protein disulfide-isomerase A3, voltage-dependent anion-selective channel protein 2. Those with a decrease in abundance were myotubularin, glutathione peroxidase, enolase, phospho glyceromutase, chloride intracellular channel protein 1. The main canonical functional pathway affected involved the unfolded protein response, aldosterone Signaling in Epithelial Cells, 14-3-3-mediated signaling. 2D-DIGE MALDI TOF mass spectrometry and network pathway analysis revealed the differential proteome expression of FreeStyle CHO cells after cryopreservation with and without 5% Me2SOto involve pathways related to post-translational modification, protein folding and cell death and survival (score = 56, 22 focus molecules). This study revealed, for the first time to our knowledge the proteins and their regulated pathways involved in the cryoprotective action of 5% Me2SO. The use of 5% Me2SO as a cryoprotectant maintained the CHO cell proteome in the cryopreserved cells, similar to that of fresh CHO cells.


Assuntos
Criopreservação , Crioprotetores/farmacologia , Dimetil Sulfóxido/farmacologia , Proteoma/efeitos dos fármacos , Animais , Células CHO , Cricetulus , Proteoma/metabolismo , Proteômica
18.
medRxiv ; 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33398295

RESUMO

A recent report found that rare predicted loss-of-function (pLOF) variants across 13 candidate genes in TLR3- and IRF7-dependent type I IFN pathways explain up to 3.5% of severe COVID-19 cases. We performed whole-exome or whole-genome sequencing of 1,934 COVID-19 cases (713 with severe and 1,221 with mild disease) and 15,251 ancestry-matched population controls across four independent COVID-19 biobanks. We then tested if rare pLOF variants in these 13 genes were associated with severe COVID-19. We identified only one rare pLOF mutation across these genes amongst 713 cases with severe COVID-19 and observed no enrichment of pLOFs in severe cases compared to population controls or mild COVID-19 cases. We find no evidence of association of rare loss-of-function variants in the proposed 13 candidate genes with severe COVID-19 outcomes.

19.
Mol Pharm ; 16(8): 3577-3587, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31291120

RESUMO

Engineered superparamagnetic iron oxide nanoparticles (SPIONs) have been studied extensively for their localized homogeneous heat generation in breast cancer therapy. However, challenges such as aggregation and inability to produce sub-10 nm SPIONs limit their potential in magnetothermal ablation. We report a facile, efficient, and robust in situ method for the synthesis of SPIONs within a poly(ethylene glycol) (PEG) reactor adsorbed onto reduced graphene oxide nanosheets (rGO) via the microwave hydrothermal route. This promising modality yields crystalline, stable, biocompatible, and superparamagnetic PEGylated SPION-rGO nanocomposites (NCs) with uniform dispersibility. Our findings show that rGO acts as a breeding ground for the spatially distributed nanosites around which the ferrihydrite seeds accumulate to ultimately transform into immobilized SPIONs. PEG, in parallel, acts as a critical confining agent physically trapping the accumulated seeds to prevent their aggregation and create multiple domains on rGO for the synthesis of quantum-sized SPIONs (9 ± 1 nm in diameter). This dual functionality (rGO and PEG) exhibits a pronounced effect on reducing both the aggregation and the sizes of fabricated SPIONs as confirmed by the scanning transmission electron microscopy images, dynamic light scattering analyses, and the specific absorption rates (SARs). Reduced aggregation lowered the toxicity of NCs, where PEGylated SPION-rGO NCs are more biocompatible than PEGylated SPIONs, showing no significant induction of cell apoptosis, mitochondrial membrane injury, or oxidative stress. Significantly less lactate dehydrogenase release and hence less necrosis are observed after 48 h exposure to high doses of PEGylated SPION-rGO NCs compared with PEGylated SPIONs. NCs induce local heat generation with a SAR value of 1760 ± 97 W/g, reaching up to 43 ± 0.3 °C and causing significant MCF-7 breast tumor cell ablation of about 78 ± 10% upon applying an external magnetic field. Collectively, rGO and PEG functionalities have a synergistic effect on improving the synthesis, stability, biocompatibility, and magnetothermal properties of SPIONs.


Assuntos
Neoplasias da Mama/terapia , Técnicas de Química Sintética/instrumentação , Química Farmacêutica/instrumentação , Nanopartículas de Magnetita/química , Nanocompostos/química , Técnicas de Química Sintética/métodos , Química Farmacêutica/métodos , Difusão Dinâmica da Luz , Feminino , Grafite/química , Humanos , Hipertermia Induzida/instrumentação , Hipertermia Induzida/métodos , Células MCF-7 , Magnetoterapia/instrumentação , Magnetoterapia/métodos , Nanopartículas de Magnetita/uso terapêutico , Nanopartículas de Magnetita/ultraestrutura , Teste de Materiais , Microscopia Eletrônica de Transmissão e Varredura , Nanocompostos/uso terapêutico , Nanocompostos/ultraestrutura , Tamanho da Partícula , Polietilenoglicóis/química
20.
ACS Appl Bio Mater ; 2(3): 970-974, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35021386

RESUMO

Natural and synthetic membrane active molecules increase the permeability of cell membranes. This can help cells combat multidrug efflux pumps as well as improve signaling and transfection. In this work, thermoresponsive metal-organic complexes (MOCs) have been constructed to transport cell impermeable cargo across the membrane through a pore-aiding assembly. These MOCs can be reversibly controlled as they collapse when the temperature is increased and are simultaneously regenerated when the system is cooled down to room temperature. These ON/OFF molecular valves can be potentially used to overcome multidrug resistance (MDR) in cancer cells and as building blocks for artificial cells.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...