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1.
Adv Funct Mater ; 33(48)2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-38144446

RESUMO

CRISPR-Cas9 is a programmable gene editing tool with a promising potential for cancer gene therapy. This therapeutic function is enabled in the present work via the non-covalent delivery of CRISPR ribonucleic protein (RNP) by cationic glucosamine/PEI-derived graphene quantum dots (PEI-GQD) that aid in overcoming physiological barriers and tracking genes of interest. PEI-GQD/RNP complex targeting the TP53 mutation overexpressed in ~50% of cancers successfully produces its double-stranded breaks in solution and in PC3 prostate cancer cells. Restoring this cancer "suicide" gene can promote cellular repair pathways and lead to cancer cell apoptosis. Its repair to the healthy form performed by simultaneous PEI-GQD delivery of CRISPR RNP and a gene repair template leads to a successful therapeutic outcome: 40% apoptotic cancer cell death, while having no effect on non-cancerous HeK293 cells. The translocation of PEI-GQD/RNP complex into PC3 cell cytoplasm is tracked via GQD intrinsic fluorescence, while EGFP-tagged RNP is detected in the cell nucleus, showing the successful detachment of the gene editing tool upon internalization. Using GQDs as non-viral delivery and imaging agents for CRISPR-Cas9 RNP sets the stage for image-guided cancer-specific gene therapy.

2.
Drug Dev Ind Pharm ; 46(10): 1559-1568, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32799687

RESUMO

Pharmaceutical cocrystals are still gaining the interest of the researchers due to their potential to alter physicochemical, mechanical, and pharmacokinetic properties of active pharmaceutical ingredients without negotiating therapeutic action. The diverse new applications of cocrystals, like taste masking, reduced toxicity, patenting opportunities, commercial potential, etc. act as driving force to the rising interest of the pharmaceutical industries. Initially, cocrystals from the view of regulatory authorities, design strategies, cocrystal preparation in brief with special emphasis on scalable and solvent-free hot melt extrusion method, and practical guide to characterization have been provided. The special focus has been given to the biopharmaceutical attributes of the cocrystal. Finally, challenges before and after cocrystal preparation are presented in this review along with some commercial examples of the cocrystals.


Assuntos
Preparações Farmacêuticas , Cristalização , Solventes/química
3.
Small ; 13(3)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28084695

RESUMO

The cytocompatibility, cell membrane affinity, and plasmid DNA delivery from surface oxidized, metal-assisted stain-etched mesoporous silicon nanoscale particles (pSiNPs) to human embryonic kidney (HEK293) cells is demonstrated, suggesting the possibility of using such material for targeted transfection and drug delivery.


Assuntos
Técnicas de Transferência de Genes , Metais/química , Nanopartículas/química , Silício/química , Análise Custo-Benefício , Fluoresceína-5-Isotiocianato , Células HEK293 , Humanos , Microscopia Confocal , Tamanho da Partícula , Porosidade , Sonicação
4.
Biotechnol Appl Biochem ; 62(4): 476-82, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25274086

RESUMO

Many potentially useful intermediates such as hydrogen and volatile fatty acids (VFAs) are formed during the complex anaerobic digestion processes that produce methane from biomass. This study recovers VFAs from an anaerobic digester by a combination of gas stripping and absorption with calcium carbonate slurry. Glucose was used as the model substrate because it is readily available, inexpensive, and easily digested. Sludge from a meatworks anaerobic digester produced methane and carbon dioxide (and sometimes a small amount of hydrogen) when batch-fed with glucose. Conditioning the neutral anaerobic sludge to an acidic pH (below 4.8) was achieved using repeated 1 g L(-1) doses of glucose. After conditioning, mainly VFAs and hydrogen were produced. The intermediate VFAs could be stripped using headspace gas. In subsequent fed-batch digestion/stripping cycles, the pH decreased when glucose was added and then increased when the VFA was gas stripped. The predominant acids formed at low pH values were lactic, butyric, and acetic acids. Lactic acid was converted to VFAs during stripping. The VFA calcium salts recovered were 80% butyrate and 20% acetate with minor quantities of propionate and valerate.


Assuntos
Bactérias Anaeróbias/metabolismo , Cálcio/metabolismo , Ácidos Graxos Voláteis/biossíntese , Glucose/metabolismo , Esgotos/microbiologia , Concentração de Íons de Hidrogênio
5.
BMC Infect Dis ; 14: 696, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25519034

RESUMO

BACKGROUND: China experiencing an increasing HIV epidemic among men who have sex with men (MSM), and unprotected anal intercourse (UAI) has played a key role in this process. The aims of this study were to examine the trend of UAI and to explore the factors correlated with UAI among MSM in Guangzhou, China. METHODS: Data from 2008 to 2013 were retrieved from the annual serological and behavioral surveys system. We collected information on demographic, HIV related sexual behavior with men and women, access to HIV prevention services, and symptoms of sexually transmitted infections. Chi-square test was used to examine the similarity of the participants during the study period. Univariate and multivariate logistic regression were conducted to test the factors associated with UAI. Trend test was used to check the change of UAI in different characteristic stratums during the study period. RESULTS: In total, 58.4% (range from 54.5% to 62.0%) of the participants reported that they engaged in UAI in the past six months. Participants who aged less than 20 [Adjusted Odds Ratio (AOR): 2.22, 95% Confidential Interval (CI): 1.07-4.61], only attended elementary school (or less) (AOR: 1.41, 95% CI: 1.04-1.90), cohabiting with male partner (AOR: 2.15, 95% CI: 1.66-2.79), divorced or widowed (AOR: 2.80, 95% CI: 1.54-5.07), did not test for HIV in the past year (AOR: 1.36, 95% CI: 1.12-1.65), and had 10 or more partners in the past six months (AOR: 1.85, 95% CI: 1.18-2.91) had higher odds of UAI. However, the proportions of UAI were stable in different stratums during the study period. CONCLUSIONS: The proportion of MSM engaged in UAI was consistently high during the study period. Effective intervention strategies, which include but not limit to risk reduction counseling and testing services, are urgently needed to bring down the risk behaviors of the MSM in Guangzhou, in order to control HIV/STIs epidemic in this specific population.


Assuntos
Homossexualidade Masculina/estatística & dados numéricos , Sexo sem Proteção/estatística & dados numéricos , Adolescente , Adulto , Idoso , China , Estudos Transversais , Inquéritos Epidemiológicos , Homossexualidade Masculina/psicologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Sexo sem Proteção/psicologia , Adulto Jovem
6.
PLOS Glob Public Health ; 4(5): e0002807, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38768141

RESUMO

While NCDs are in rise globally, tribal and rural populations residing near to reserve forests with limited exposure to modern lifestyles may bear a unique burden. This study investigates the prevalence and risk factors of hypertension, diabetes, and dyslipidemia among these communities. We conducted a cross-sectional study between 2018 and 2020 in the forest-dwelling population of Chamarajanagar, India. Using multistage stratified sampling based on caste and remoteness, we enrolled 608 participants aged over 18 years, including 259 non-tribal and 349 tribal individuals. Data collection includes the administration of STEPS questionnaire and measurement of fasting blood sugar, lipid levels, and blood pressure. The prevalence of diabetes, hypertension, and dyslipidemia were 4.6%, 28.8%, and 85.7%, respectively, among the study population. We also found abnormal levels of low-density lipoprotein (LDL), high-density lipoprotein (HDL), Triglycerides (TGA), Total cholesterol (TC), and very low-density lipoprotein (VLDL)in 4.9%, 82.4%, 22.7%, 5.8%, and 7.4% of participants, respectively. Significant differences were observed in diabetes, LDL abnormality, TGA abnormality, VLDL abnormality, and TC abnormality, but not in hypertension, dyslipidemia, or HDL abnormality, across the Socio Geographic Discrimination Index. We found a significant difference in diabetes and HDL abnormality, but not in hypertension, dyslipidemia, LDL abnormality, TGA abnormality, TC abnormality, or VLDL abnormality, between tribal and non-tribal populations living in the forest-dwelling area. Waist circumference was a significant independent predictor of diabetes among tribal participants, while wealth index, age, and waist circumference were significant predictors of hypertension. There were no significant predictors for dyslipidemia among tribal participants. Our study suggests that tribal population living in a remote area are at a lower risk of developing diabetes compared to non-tribal populations living in the same geographic area. However, the prevalence of hypertension and dyslipidemia among tribal populations remains high and comparable to that of the general population.

7.
Bioorg Med Chem Lett ; 23(13): 3959-66, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23683590

RESUMO

Multiple-targeted ligands can have certain advantages for the management of hypertension which has multiple controls. Molecules with dual bioactivities are available in literature for treating metabolic disorders like diabetes, hypertension and hypercholesterolemia. After scrutinizing the SAR of prazosin-type α1-blockers and AII-antagonists it was planned to develop dual α1- and AII-antagonists. Five series of quinazoline derivatives were synthesized and evaluated as dual α1- and AII-antagonists on rat aortic strips for the blockade of known α1- and AII-agonist mediated contractions. Many compounds showed balanced activity on both the receptors but compound (22) was found to be the most active derivative having higher antagonistic activity on both the receptors. In the in vivo experiments the chosen compound (22) was slightly less active than prazosin but was found to be equipotent to losartan. These findings shed a new light on the structural requirements for both α1- as well as AII-receptor antagonists.


Assuntos
Desenho de Fármacos , Quinazolinas/farmacologia , Receptores Adrenérgicos alfa 1/metabolismo , Receptores de Angiotensina/metabolismo , Animais , Relação Dose-Resposta a Droga , Humanos , Ligantes , Estrutura Molecular , Quinazolinas/administração & dosagem , Quinazolinas/síntese química , Ratos , Relação Estrutura-Atividade
8.
PLoS One ; 18(10): e0292139, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37796890

RESUMO

Obesity in children is a major public health concern due to the increased risk of developing adverse health outcomes in their future, and disability in adulthood. The existing systematic reviews on the topic are limited in scope, focusing solely on high-income countries and children aged 4-12 years. Hence, we propose to conduct a systematic review and meta-analysis to understand, how exposure to authoritative feeding style versus authoritarian, indulgent, uninvolved compare in terms of its association with adiposity in children aged 6 months to 5 years. Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines were followed for ensuring the completeness of the protocol. Case-control and cohort studies will be included. Searches will be done using electronic databases viz. PubMed, Ovid EMBASE, PsycINFO and Web of Science. Grey literature will be searched using OpenGrey and Grey Literature Report. We will only include quantitative studies using the developed search strategy. For categorical outcomes, relative risks, odds ratios, and hazard ratios with confidence intervals and for continuous outcomes mean difference with confidence intervals will be used. Risk of Bias In Non-randomized Studies- of Exposure (ROBINS-E) will be used for the evaluation of risk of bias in the individual observational studies. Considering the inherent variability in the observational studies, random effects meta-analysis will also be conducted. If between-study heterogeneity exists, a subgroup analysis based on low and middle-income countries vs. high income countries will be conducted. If the data is not suitable for combining quantitatively, a narrative synthesis will be undertaken. We propose to identify publication bias by using contour-enhanced funnel plots and "trim and fill" method. Outcome reporting bias will be ascertained by comparing the outcomes published in the protocol and the published report. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system will be used to understand the confidence we can have on the effect estimates. Registration: This protocol has been registered in International Prospective Register of Systematic Reviews (PROSPERO) on 13 March 2023 with registration number CRD42023356014.


Assuntos
Doenças Profissionais , Exposição Ocupacional , Obesidade Infantil , Criança , Humanos , Adiposidade , Organização Mundial da Saúde , Efeitos Psicossociais da Doença , Revisões Sistemáticas como Assunto , Metanálise como Assunto
9.
Wellcome Open Res ; 8: 155, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37766856

RESUMO

In this correspondence, we, co-authors and collaborators involved in the Towards Health Equity and Transformative Action on tribal health (THETA) study respond to a recent article published in Wellcome Open Research titled  Correspondence article on the research protocol titled 'Towards Health Equity and Transformative Action on tribal health (THETA) study to describe, explain and act on tribal health inequities in India: A health systems research study protocol' published in Wellcome Open Research in December 2019 In the first part, we provide overall clarifications on the THETA study and in the second part respond to specific comments by the authors of the aforementioned correspondence.

10.
Bioorg Med Chem ; 20(21): 6296-304, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23040894

RESUMO

Plasmodium falciparum cysteine protease falcipain-2 (FP-2) is a promising target for antimalarial chemotherapy and inhibition of this protease affects the growth of parasite adversely. A series of pyrido[1,2-a]pyrimidin-4-ones were synthesized and evaluated for their in vitro FP-2 inhibitory potential. Compounds (14,17) showed excellent FP-2 inhibition and can serve as lead compounds for further development of potent FP-2 inhibitors as potential antimalarial drugs.


Assuntos
Antimaláricos/farmacologia , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Plasmodium falciparum/enzimologia , Pirimidinonas/farmacologia , Antimaláricos/síntese química , Antimaláricos/química , Inibidores de Cisteína Proteinase/síntese química , Inibidores de Cisteína Proteinase/química , Relação Dose-Resposta a Droga , Estrutura Molecular , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento , Pirimidinonas/síntese química , Pirimidinonas/química , Relação Estrutura-Atividade
11.
Pharm Biol ; 50(4): 439-42, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22136253

RESUMO

CONTEXT: The problem of hypertension has gained enormous proportions in the past decade. Multifactorial etiology and complex pathophysiology of the disease has rendered the treatment of the disease a hard task. Sympathetic nervous system and the renin-angiotensin-aldosterone system are primary contributors of blood pressure homeostasis. OBJECTIVE: Structural similarities were identified among AT(1) and α(1)-antagonists, initiating a speculation that α(1)-antagonists could possibly block the AT(1) receptor and vice-versa. METHODS: To corroborate this speculation, we screened prototypical α(1)-antagonists such as prazosin, doxazosin, and terazosin for antagonism of angiotensin II on rat aortic strips. We also examined the AT(1) antagonists losartan, valsartan, and olmesartan for their possible antagonistic effect, on contractions of rat aortic strips induced by phenylephrine. RESULTS: To our astonishment, we found that prazosin and its analogs which have been reported to have α(1)-antagonistic activity only, were able to shift concentration response curves of angiotensin II. CONCLUSION: Our findings suggest that the potent antihypertensive effect of prazosin-type α(1)-antagonists is not purely due to α(1)-receptor blocking activity of these compounds but also due to blockade of AT(1) receptors. This finding may lead to the development of more potent dual inhibitors which would prove to be of immense value in the control of the scourge of hypertension.


Assuntos
Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Anti-Hipertensivos/farmacologia , Aorta Torácica/efeitos dos fármacos , Receptor Tipo 1 de Angiotensina/efeitos dos fármacos , Receptores Adrenérgicos alfa 1/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 1/química , Bloqueadores do Receptor Tipo 1 de Angiotensina II/química , Animais , Anti-Hipertensivos/química , Aorta Torácica/metabolismo , Relação Dose-Resposta a Droga , Doxazossina/farmacologia , Imidazóis/farmacologia , Técnicas In Vitro , Losartan/farmacologia , Masculino , Estrutura Molecular , Prazosina/análogos & derivados , Prazosina/farmacologia , Ratos , Ratos Wistar , Receptor Tipo 1 de Angiotensina/metabolismo , Receptores Adrenérgicos alfa 1/metabolismo , Relação Estrutura-Atividade , Tetrazóis/farmacologia , Valina/análogos & derivados , Valina/farmacologia , Valsartana , Vasodilatadores/química
12.
ACS Biomater Sci Eng ; 8(11): 4965-4975, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36179254

RESUMO

Sonography offers many advantages over standard methods of diagnostic imaging due to its non-invasiveness, substantial tissue penetration depth, and low cost. The benefits of ultrasound imaging call for the development of ultrasound-trackable drug delivery vehicles that can address a variety of therapeutic targets. One disadvantage of the technique is the lack of high-precision imaging, which can be circumvented by complementing ultrasound contrast agents with visible and, especially, near-infrared (NIR) fluorophores. In this work, we, for the first time, develop a variety of lightly metal-doped (iron oxide, silver, thulium, neodymium, cerium oxide, cerium chloride, and molybdenum disulfide) nitrogen-containing graphene quantum dots (NGQDs) that demonstrate high-contrast properties in the ultrasound brightness mode and exhibit visible and/or near-infrared fluorescence imaging capabilities. NGQDs synthesized from glucosamine precursors with only a few percent metal doping do not introduce additional toxicity in vitro, yielding over 80% cell viability up to 2 mg/mL doses. Their small (<50 nm) sizes warrant effective cell internalization, while oxygen-containing surface functional groups decorating their surfaces render NGQDs water soluble and allow for the attachment of therapeutics and targeting agents. Utilizing visible and/or NIR fluorescence, we demonstrate that metal-doped NGQDs experience maximum accumulation within the HEK-293 cells 6-12 h after treatment. The successful 10-fold ultrasound signal enhancement is observed at 0.5-1.6 mg/mL for most metal-doped NGQDs in the vascular phantom, agarose gel, and animal tissue. A combination of non-invasive ultrasound imaging with capabilities of high-precision fluorescence tracking makes these metal-doped NGQDs a viable agent for a variety of theragnostic applications.


Assuntos
Grafite , Pontos Quânticos , Animais , Humanos , Células HEK293 , Nitrogênio , Imagem Óptica , Ultrassonografia
13.
Materials (Basel) ; 15(16)2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-36013894

RESUMO

Early-stage pancreatic cancer remains challenging to detect, leading to a poor five-year patient survival rate. This obstacle necessitates the development of early detection approaches based on novel technologies and materials. In this work, the presence of a specific pancreatic cancer-derived miRNA (pre-miR-132) is detected using the fluorescence properties of biocompatible nitrogen-doped graphene quantum dots (NGQDs) synthesized using a bottom-up approach from a single glucosamine precursor. The sensor platform is comprised of slightly positively charged (1.14 ± 0.36 mV) NGQDs bound via π-π stacking and/or electrostatic interactions to the negatively charged (-22.4 ± 6.00 mV) bait ssDNA; together, they form a complex with a 20 nm average size. The NGQDs' fluorescence distinguishes specific single-stranded DNA sequences due to bait-target complementarity, discriminating them from random control sequences with sensitivity in the micromolar range. Furthermore, this targetability can also detect the stem and loop portions of pre-miR-132, adding to the practicality of the biosensor. This non-invasive approach allows cancer-specific miRNA detection to facilitate early diagnosis of various forms of cancer.

14.
Bioorg Med Chem ; 19(17): 5093-102, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21839641

RESUMO

A compound that can target cells expressing the estrogen receptor (ER), and produce predominantly 3-MeA adducts in those cells has been designed and synthesized. This compound produces mainly the 3-MeA adduct upon reaction with calf thymus DNA, and binds to the ER with a relative binding affinity of 51% (estradiol = 100%). The compound is toxic to ER-expressing MCF-7 breast cancer cells, and pre-treatment with the ER antagonist fulvestrant abrogates the toxicity. Pre-treatment of MCF-7 cells with netropsin, which inhibits N3-adenine methylation by the compound, resulted in a threefold decrease in the toxicity. These results demonstrate the feasibility of this strategy for producing 3-MeA adducts in targeted cells.


Assuntos
Adenina/química , DNA/química , Receptores de Estrogênio/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , DNA/metabolismo , Metilação de DNA , Estradiol/análogos & derivados , Estradiol/farmacologia , Fulvestranto , Humanos , Simulação de Dinâmica Molecular , Netropsina/farmacologia , Ligação Proteica , Receptores de Estrogênio/antagonistas & inibidores
15.
Nanomaterials (Basel) ; 11(1)2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33435595

RESUMO

With 18 million new cases diagnosed each year worldwide, cancer strongly impacts both science and society. Current models of cancer cell growth and therapeutic efficacy in vitro are time-dependent and often do not consider the Emax value (the maximum reduction in the growth rate), leading to inconsistencies in the obtained IC50 (concentration of the drug at half maximum effect). In this work, we introduce a new dual experimental/modeling approach to model HeLa and MCF-7 cancer cell growth and assess the efficacy of doxorubicin chemotherapeutics, whether alone or delivered by novel nitrogen-doped graphene quantum dots (N-GQDs). These biocompatible/biodegradable nanoparticles were used for the first time in this work for the delivery and fluorescence tracking of doxorubicin, ultimately decreasing its IC50 by over 1.5 and allowing for the use of up to 10 times lower doses of the drug to achieve the same therapeutic effect. Based on the experimental in vitro studies with nanomaterial-delivered chemotherapy, we also developed a method of cancer cell growth modeling that (1) includes an Emax value, which is often not characterized, and (2), most importantly, is measurement time-independent. This will allow for the more consistent assessment of the efficiency of anti-cancer drugs and nanomaterial-delivered formulations, as well as efficacy improvements of nanomaterial delivery.

16.
J Med Chem ; 64(17): 12651-12669, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34415160

RESUMO

We previously described the development of a DNA-alkylating compound that showed selective toxicity in breast cancer cells. This compound contained an estrogen receptor α (ERα)-binding ligand and a DNA-binding/methylating component that could selectively methylate the N3-position of adenines at adenine-thymine rich regions of DNA. Herein, we describe mechanistic investigations that demonstrate that this class of compounds facilitate the translocation of the ERα-compound complex to the nucleus and induce the expression of ERα target genes. We confirm that the compounds show selective toxicity in ERα-expressing cells, induce ERα localization in the nucleus, and verify the essential role of ERα in modulating the toxicity. Minor alterations in the compound structure significantly affects the DNA binding ability, which correlates to the DNA-methylating ability. These studies demonstrate the utility of DNA-alkylating compounds to accomplish targeted inhibition of the growth of specific cancer cells; an approach that may overcome shortcomings of currently used chemotherapy agents.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Metilação de DNA , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Estradiol/administração & dosagem , Estradiol/farmacologia , Feminino , Humanos , Células MCF-7 , Modelos Moleculares , Simulação de Dinâmica Molecular , Estrutura Molecular , Relação Estrutura-Atividade
17.
ACS Appl Bio Mater ; 3(1): 208-216, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35019437

RESUMO

Biodegradable porous silicon nanotubes (pSiNTs), functionalized with primary amine moieties via the use of 3-aminopropyltriethoxysilane (APTES), is demonstrated as a template for formation of platinum nanocrystals (Pt NCs) (1-3 nm). Transmission electron microscopy-energy dispersive X-ray analysis (TEM-EDX) indicates a relatively high and tunable concentration of Pt uniformly immobilized on a given nanotube (wt % Pt: 20-60%). In vitro viability and cellular uptake studies are consistent with a time-dependent toxicity of Pt NCs-pSiNTs against HeLa cells that is influenced by the degradation kinetics of the pSiNTs; internalization of the composites inside the cells exerts cellular damage in an apoptotic manner, therefore suggesting promising future applications in anticancer treatments.

18.
ACS Omega ; 4(5): 8359-8364, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31459924

RESUMO

The properties of nanostructured plant-derived porous silicon (pSi) microparticles as potential candidates to increase the bioavailability of plant extracts possessing anti-inflammatory activity are described in this work. pSi drug carriers were fabricated using an eco-friendly route from the silicon accumulator plant bamboo (tabasheer) powder by magnesiothermic reduction of plant-derived silica and loaded with ethanolic extracts of Equisetum arvense, another silicon accumulator plant rich in polyphenolic compounds. The anti-inflammatory properties of the active therapeutics present in this extract were measured by sensitive luciferase reporter assays; this active extract was subsequently loaded and released from the pSi matrix, with a clear inhibition of the activity of the inflammatory signaling protein NF-κB over a period of hours in a sustained manner. Our results showed that after loading the extracts of E. arvense into pSi microparticles derived from tabasheer, enhanced anti-inflammatory activity was observed owing to enhanced solubility of the extract.

19.
ACS Biomater Sci Eng ; 5(9): 4671-4682, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-33448839

RESUMO

Despite significant advances of nanomedicine, the issues of biocompatibility, accumulation-derived toxicity, and the lack of sensing and in vivo imaging capabilities hamper the translation of most nanocarriers into clinic. To address this, we utilize nitrogen, boron/nitrogen, and sulfur-doped graphene quantum dots (GQDs) as fully biocompatible multifunctional platforms allowing for multicolor visible/near-IR imaging and cancer-sensing. These GQDs are scalably produced in one-step synthesis from a single biocompatible glucosamine precursor, are water-soluble, show no cytotoxicity at high concentrations of 1 mg/mL, and demonstrate substantial degradation at 36 h in biological environments as verified by TEM imaging. Because of their small sizes, GQDs exhibit efficient internalization maximized at 12 h followed by further degradation/excretion. Their high-yield intrinsic fluorescence in blue/green and near-infrared allows for multicolor in vitro imaging on its own or in combination with other fluorophores, and offers the capabilities for in vivo near-IR fluorescence tracking. Additionally, nitrogen- and sulfur-doped GQDs exhibit pH-dependent fluorescence response that is successfully utilized as a sensing mechanism for acidic extracellular environments of cancer cells. It allows for the deterministic, ratiometric spectral discrimination between cancerous (HeLa and MCF-7 cell) versus healthy (HEK-293 cell) environments with substantial intensity ratios of 1.6 to 8. These results suggest fully biocompatible GQDs developed in this work as multifunctional candidates for in vitro delivery of active agents, multicolor visible/near-IR fluorescence imaging, and pH-sensing of cancerous environments.

20.
Biotechnol Bioeng ; 99(4): 1034-9, 2008 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-17705233

RESUMO

A method of rapid determination of chlorophyll a and lipid contents of microalgae based on colorimetric analysis of the digital images of the microalgae is proposed. The color variation of microalgae during cultivation is evaluated by the brightness of the three primary colors (red, green, and blue). The brightness values of the three primary colors are modeled as two linear correlation functions (RGB model) for microalgal chlorophyll a and lipid contents, respectively. The chlorophyll a and lipid contents predicted by the proposed model are compared with that determined by the standard methods. The good agreement of the model predictions with experimental results is demonstrated with a squared correlation coefficient (R(2)) of 0.99 for chlorophyll a and lipid. The reliability of the RGB model was verified in real cultivations of the microalgae in a photobioreactor. Growth dynamics, contents of chlorophyll a and lipid corresponded very well with previously reported studies.


Assuntos
Algoritmos , Clorofila/metabolismo , Colorimetria/métodos , Eucariotos/metabolismo , Lipídeos/análise , Modelos Biológicos , Clorofila A , Simulação por Computador
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