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1.
J Am Chem Soc ; 139(5): 1746-1749, 2017 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-28106386

RESUMO

Reversible switching of photoluminescence (PL) of carbon nanoparticles (CNP) can be achieved with counterionic macromolecular caging and decaging at the nanoscale. A negatively charged uncoated, "bare" CNP with high luminescence loses its PL when positively charged macromolecules are wrapped around its surface. Prepared caged carbons could regain their emission only through interaction with anionic surfactant molecules, representing anionic amphiphiles of endocytic membranes. This process could be verified by gel electrophoresis, spectroscopically and in vitro confocal imaging studies. Results indicated for the first time that luminescence switchable CNPs can be synthesized for efficient intracellular tracking. This study further supports the origin of photoluminescence in CNP as a surface phenomenon correlated a function of characteristic charged macromolecules.

2.
Anal Chem ; 89(3): 2107-2115, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28050904

RESUMO

Cortisol has been identified as a biomarker in saliva to monitor psychological stress. In this work, we report a label-free paper-based electrical biosensor chip to quantify salivary cortisol at a point-of-care (POC) level. A high specificity of the sensor chip to detect cortisol with a detection limit of 3 pg/mL was achieved by conjugating anticortisol antibody (anti-CAB) on top of gold (Au) microelectrodes using 3,3'-dithiodipropionic acid di(N-hydroxysuccinimide ester (DTSP) as a self-assembled monolayer (SAM) agent. The electrode design utilized poly(styrene)-block-poly(acrylic acid) (PS67-b-PAA27) polymer and graphene nanoplatelets (GP) suspension coated on filter paper to increase the sensitivity of the immune response. A biosensor chip was then integrated with a lab-built low-cost miniaturized printed circuit board (PCB) to provide an electrical connection and to wirelessly transmit/receive electrical signals using MATLAB. This fully integrated proposed hand-held device successfully exhibited a wide cortisol-detection range from 3 pg/mL to 10 µg/mL, with a sensitivity of 50 Ω (pg mL-1)-1. The performance of the proposed cortisol sensor chip was validated using an enzyme-linked immunosorbent assay (ELISA) technique with a regression value of 0.9951. The advantages of the newly developed cortisol immune biosensor over previously reported chips include an improved limit of detection, no need for additional redox medium for electron exchange, faster response to achieve stable data, excellent shelf life, and its economical production.


Assuntos
Resinas Acrílicas/química , Técnicas Biossensoriais/instrumentação , Técnicas de Química Analítica/instrumentação , Grafite/química , Hidrocortisona/análise , Papel , Poliestirenos/química , Saliva/química , Biomarcadores/análise , Técnicas Biossensoriais/economia , Técnicas de Química Analítica/economia , Ensaio de Imunoadsorção Enzimática , Ouro/química , Voluntários Saudáveis , Humanos , Limite de Detecção , Microeletrodos , Reprodutibilidade dos Testes , Estresse Psicológico/diagnóstico , Succinimidas/química
3.
Small ; 12(42): 5845-5861, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27545321

RESUMO

Signal transducer and activator of transcription factor 3 (STAT-3) is known to be overexpressed in cancer stem cells. Poor solubility and variable drug absorption are linked to low bioavailability and decreased efficacy. Many of the drugs regulating STAT-3 expression lack aqueous solubility; hence hindering efficient bioavailability. A theranostics nanoplatform based on luminescent carbon particles decorated with cucurbit[6]uril is introduced for enhancing the solubility of niclosamide, a STAT-3 inhibitor. The host-guest chemistry between cucurbit[6]uril and niclosamide makes the delivery of the hydrophobic drug feasible while carbon nanoparticles enhance cellular internalization. Extensive physicochemical characterizations confirm successful synthesis. Subsequently, the host-guest chemistry of niclosamide and cucurbit[6]uril is studied experimentally and computationally. In vitro assessments in human breast cancer cells indicate approximately twofold enhancement in IC50 of drug. Fourier transform infrared and fluorescence imaging demonstrate efficient cellular internalization. Furthermore, the catalytic biodegradation of the nanoplatforms occur upon exposure to human myeloperoxidase in short time. In vivo studies on athymic mice with MCF-7 xenograft indicate the size of tumor in the treatment group is half of the controls after 40 d. Immunohistochemistry corroborates the downregulation of STAT-3 phosphorylation. Overall, the host-guest chemistry on nanocarbon acts as a novel arsenal for STAT-3 inhibition.

4.
Chem Commun (Camb) ; 59(90): 13434-13437, 2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-37847141

RESUMO

The improper disposal of hospital waste products containing genetic materials poses a serious safety threat. We present herein an environmentally friendly technology using a graphene-based novel carbon-allotropic surface to remediate such wastes. The used carbon-allotrope is decorated with an enediyne (EDE-1) enriched aromatic pi-conjugated structure to create an efficient and active surface for cleaving DNA strands. Under controlled exposure of ultraviolet (UV) radiation and heat, the developed surface influences genetic degradation without disturbing the bacterial populations present downstream of the water treatment system. The designed material has been extensively characterized using physicochemical and biological tools. Our results indicate that this approach can possibly be introduced in large scale hospital waste disposal streams for remediating genetic hazards and thereby developing a portable self-contained system.


Assuntos
Carbono , Grafite , Bactérias , DNA , Enedi-Inos
5.
Nat Commun ; 11(1): 4530, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913195

RESUMO

Various cancer cells have been demonstrated to have the capacity to form plasmonic gold nanoparticles when chloroauric acid is introduced to their cellular microenvironment. But their biomedical applications are limited, particularly considering the millimolar concentrations and longer incubation period of ionic gold. Here, we describe a simplistic method of intracellular biomineralization to produce plasmonic gold nanoparticles at micromolar concentrations within 30 min of application utilizing polyethylene glycol as delivery vector for ionic gold. We have characterized this process for intracellular gold nanoparticle formation, which progressively accumulates proteins as the ionic gold clusters migrate to the nucleus. This nano-vectorized application of ionic gold emphasizes its potential biomedical opportunities while reducing the quantity of ionic gold and required incubation time. To demonstrate its biomedical potential, we further induce in-situ biosynthesis of gold nanoparticles within MCF7 tumor mouse xenografts which is followed by its photothermal remediation.


Assuntos
Cloretos/administração & dosagem , Portadores de Fármacos/química , Compostos de Ouro/administração & dosagem , Ouro/química , Nanopartículas Metálicas/química , Neoplasias/tratamento farmacológico , Nanomedicina Teranóstica/métodos , Animais , Biomineralização/efeitos da radiação , Feminino , Ouro/efeitos da radiação , Humanos , Hipertermia Induzida/métodos , Íons , Células MCF-7 , Nanopartículas Metálicas/efeitos da radiação , Camundongos , Fotoquimioterapia/métodos , Polietilenoglicóis/química , Ensaios Antitumorais Modelo de Xenoenxerto
6.
ACS Biomater Sci Eng ; 4(4): 1357-1367, 2018 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33418666

RESUMO

Theranostic nanoparticles have incredible potential for biomedical applications by enabling visual confirmation of therapeutic efficacy. Numerous issues challenge their clinical translation and are primarily related to the complex chemistry and scalability of synthesizing Nanoparticles. We report a 2-step chemical strategy for high-throughput intracellular delivery of organic and inorganic solid nanoparticles. This process takes an additional step beyond hydrophobic surface modification facilitated by inverted micelle transfer, toward the packing of multiple solid nanoparticles into a soft-shelled lipid capsule, termed the Nano-multicapsule (NMC). This technique is high yielding and does not require the complex purification steps in anaerobic/hydrophobic reactions for hydrophobic modification. To demonstrate the efficacy across different material compositions, we separately entrapped ∼10 nm gold and carbon nanoparticles (AuNP and CNP) within inverted micelles, and subsequently NMCs, then quantified their internalization in a human breast cancer cell line. For encapsulated AuNPs (NMC-AuNP), we confirmed greater cellular internalization of gold through ICP-OES and TEM analyses. Raman spectroscopic analysis of cells treated with encapsulated CNPs (NMC-CNP) also exhibited high degrees of uptake with apparent intracellular localization as opposed to free CNP treatment.

7.
ACS Appl Mater Interfaces ; 9(10): 8609-8622, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28207238

RESUMO

Lack of current techniques for the early monitoring of bleb leaks and other post-traumatic or post-surgical ocular injury has posed an unmet clinical need for the development of new techniques. Present evaluation techniques use either subjective or nonquantitative approaches. At present, there are no FDA approved ocular devices that can directly measure ascorbic acid (AA) concentration levels for both tear film (TF) and aqueous humor (AH) at point-of-care (POC) level. Toward this aim, we present a novel POC quantitative assay, called the ocular biosensor device, which can be used to evaluate the integrity of the anterior surface of the eye by measuring the concentration of AA in TF and AH. Herein, we utilize a novel scientific engineering approach for the development of a disposable paper based POC ocular biosensor strip. A grafted poly(styrene)-block-poly(acrylic acid) (PS-b-PAA) and graphene platelet composite with contour based µ-electrodes design (CBµE) exhibit a highly sensitive platform to perform electrochemical immunosensing technique to study clinical samples that have small volumes like tear fluid. Samples used in this study were collected clinically from subjects undergoing therapeutic anterior chamber paracentesis. The proposed biosensor reports the level of AA concentration on an electronic screen, making the results easy to read, efficient, and reliable.


Assuntos
Traumatismos Oculares , Técnicas Biossensoriais , Técnicas Eletroquímicas , Eletrodos , Grafite , Humanos
8.
Sci Rep ; 7: 41880, 2017 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-28157204

RESUMO

Increasingly frequent petroleum contamination in water bodies continues to threaten our ecosystem, which lacks efficient and safe remediation tactics both on macro and nanoscales. Current nanomaterial and dispersant remediation methods neglect to investigate their adverse environmental and biological impact, which can lead to a synergistic chemical imbalance. In response to this rising threat, a highly efficient, environmentally friendly and biocompatible nano-dispersant has been developed comprising a multi-shelled nanoparticle termed 'Nano-CarboScavengers' (NCS) with native properties for facile recovery via booms and mesh tools. NCS treated different forms of petroleum oil (raw and distillate form) with considerable efficiency (80% and 91%, respectively) utilizing sequestration and dispersion abilities in tandem with a ~10:1 (oil: NCS; w/w) loading capacity. In extreme contrast with chemical dispersants, the NCS was found to be remarkably benign in in vitro and in vivo assays. Additionally, the carbonaceous nature of NCS broke down by human myeloperoxidase and horseradish peroxidase enzymes, revealing that incidental biological uptake can enzymatically digest the sugar based core.

9.
ACS Appl Mater Interfaces ; 9(25): 21147-21154, 2017 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-28581711

RESUMO

Spheroidal nanoparticles of algal ("phytonic") origin were synthesized and composed of carbonaceous architectures and surface-rich oxygenated functional groups. Nanoparticles were negatively charged and efficiently luminescent after ultraviolet-range excitation and called as "photophytonic" nanoparticles. A multitude of analytical techniques confirmed the rich profusion of hydroxyl, carboxylate, and amines at the nanoscale, while spectroscopic investigation indicated the presence of α-amines, a signature functionality present in amino acids. Confirmed via a series of biological assays, i.e., growth regression, antimigration, and protein-regression studies, photophytonic nanoparticles serendipitously revealed remarkable anticancer activity against various stages of breast cancer cells, barring the need for an encapsulated drug. We report that nanoparticles derived from algal biomass exhibit intrinsic antimigratory properties against cancer, likely due to the rich abundance of α-amino acids.


Assuntos
Nanopartículas , Aminoácidos , Biomassa , Humanos , Neoplasias
10.
ACS Appl Mater Interfaces ; 8(40): 26600-26612, 2016 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-27662498

RESUMO

The use of cesium chloride (CsCl) for cancer therapy ("high pH therapy") has been theorized to produce anticancer properties by raising intracellular pH to induce apoptosis. Although considered as "alternative medicine", little scientific evidence supports this theory. Alternatively, cells have no cesium ion (Cs+) mediated channels for clearance. Thus, such unstable electrochemical distributions have the severe potential to disrupt electrochemical dependent cellular processes, such as glucose cotransporters. Hence, a detailed investigation of pH changing effects and glucose uptake inhibition are warranted as a possible cesium-induced anticancer therapy. We developed and characterized cesium nanoparticles (38 ± 6 nm), termed NanoCs, for nanoparticle-mediated internalization of the ion, and compared its treatment to free CsCl. Our investigations suggest that neither NanoCs nor CsCl drastically changed the intracellular pH, negating the theory. Alternatively, NanoCs lead to a significant decrease in glucose uptake when compared to free CsCl, suggesting cesium inhibited glucose uptake. An apoptosis assay of observed cell death affirms that NanoCs leads tumor cells to initiate apoptosis rather than follow necrotic behavior. Furthermore, NanoCs lead to in vivo tumor regression, where H&E analysis confirmed apoptotic cell populations. Thus, NanoCs performed pH-independent anticancer therapy by inducing metabolic stasis.

11.
Chem Commun (Camb) ; 52(47): 7513-6, 2016 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-27214647

RESUMO

Chiral carbon nanoparticles (CCNPs) were developed by surface passivation using the chiral ligand (-)-sparteine or (+)-sparteine (denoted (-)-SP/CNP and (+)-SP/CNP, respectively). The chirality of the prepared CCNPs was demonstrated by circular dichroism and polarimetry and employed as an enantioselective separation platform for representative racemic mixtures.

12.
J Laparoendosc Adv Surg Tech A ; 12(6): 411-7, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12590721

RESUMO

OBJECTIVE: Rising costs and lowered reimbursements make value essential if laparoscopic cholecystectomy (LC) is to be offered to patients without condemning providers to financial loss. We hypothesize that our protocol increases this value. Once practiced, operative time, complications, and patient satisfaction compare with those of the typical method. METHODS: We prospectively randomized 50 consecutive patients equally to control or experimental LC according to our protocol. Equipment costs, operative time, conversions, complications, pain, and return to work were compared. The student's t test was used for comparisons. RESULTS: Mean disposable equipment costs were 173.00 dollars +/- 43.45 dollars and 434.42 dollars +/- 50.54 dollars for the study and control groups, respectively (P < .0001). Mean operative times were 67.26 +/- 15 and 70.60 +/- 19 minutes, respectively. CONCLUSIONS: The "bare bones" protocol is safe. It has a short learning curve, demonstrates a cost advantage over the common method, and requires no additional operative time. Pain, time to return to work, and satisfaction are equivalent.


Assuntos
Colecistectomia Laparoscópica/economia , Equipamentos Descartáveis/economia , Adulto , Colecistectomia Laparoscópica/métodos , Redução de Custos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo
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