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1.
J Am Chem Soc ; 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058398

RESUMO

Inspired by the unique functionalities of biomolecular membraneless organelles (MLOs) formed via liquid-liquid phase separation (LLPS) of intrinsically disordered proteins (IDPs) and nucleic acids, a great deal of effort has been devoted to devising phase-separated artificial subcellular dynamic compartments. These endeavors aim to unravel the molecular mechanism underlying the formation and intracellular delivery of susceptible macromolecular therapeutics. We report herein pyroglutamic acid (PGA)-based well-defined homopolymers featuring stimuli-tunable reversible self-coacervation ability. The polymer exhibits an upper critical solution temperature (UCST) transition in aqueous solutions and has the propensity to undergo cooling-induced LLPS, producing micrometer-sized liquid droplets. This phase separation phenomenon could be modulated by various factors, including polymer concentration, chain length, solution pH, and types and concentrations of different additives. These micrometer droplets are thermally reversible and encapsulate a wide variety of cargoes, including small hydrophobic fluorescent molecules, hydrophilic anticancer drugs, and fluorophore-labeled macromolecular proteins (bovine serum albumin and lysozyme). The payloads were released by exploiting the thermo/pH-mediated disassembly behavior of the coacervates, preserving the bioactivity of the sensitive therapeutics. This environmentally responsive, simple yet versatile artificial MLO model system will provide insights into the biomolecular nonionic condensates and pave the way for the de novo design of dynamic biomolecule depots.

2.
Langmuir ; 40(10): 5314-5325, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38408899

RESUMO

Zwitterionic polymers are an emerging family of effective, low-fouling materials that can withstand unintended interactions with biological systems while exhibiting enhanced activity in bacterial matrix deterioration and biofilm eradication. Herein, we modularly synthesized an amphiphilic block copolymer, ZABCP, featuring potential bacteriostatic properties composed of a charge-switchable polyzwitterionic segment and a redox-sensitive pendant disulfide-labeled polymethacrylate block. The leucine-appended polyzwitterionic segment with alternatively positioned cationic amine and anionic carboxylate functionalities undergoes charge alterations (+ve → 0 → -ve) on pH variation. By introducing appropriate amphiphilicity, ZABCP forms distinct vesicles with redox-sensitive bilayer membranes and zwitterionic shielding coronas, enabling switching of surface charge. ZABCP vesicles exhibit 180 ± 20 nm hydrodynamic diameter, and its charge switching behavior in response to pH was confirmed by the change of zeta potential value from -23 to +36 mV. The binding interaction between ZABCP vesicles with lysozyme and pepsin proteins strengthens when the surface charge shifts from neutral (pH 7.4) to either anionic or cationic. This surface-charge-switchable phenomenon paves the way for implementing cationic ZABCP vesicles for bacterial cell growth inhibition, which is shown by the pronounced transition of cellular morphology, including clustering, aggregation, or elongation as well as membrane disruption for both Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative). Such enhanced bacteriostatic activity could be ascribed to a strong electrostatic interaction between cationic vesicles and negatively charged bacterial membranes, leading to cell membrane disruption. Overall, this study provides a tailor-made approach to adopt low-fouling properties and potential bacteriostatic activity using zwitterionic polymers through precise control of pH.


Assuntos
Incrustação Biológica , Incrustação Biológica/prevenção & controle , Proteínas/metabolismo , Cátions/química , Membrana Celular/metabolismo , Polímeros/química , Propriedades de Superfície
3.
Biomacromolecules ; 25(5): 3200-3211, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38591457

RESUMO

Achieving efficient and site-specific conjugation of therapeutic protein to polymer is crucial to augment their applicability in the realms of biomedicine by improving their stability and enzymatic activity. In this study, we exploited tetrazine bioorthogonal chemistry to achieve the site-specific conjugation of bottlebrush polymers to urate oxidase (UOX), a therapeutic protein for gout treatment. An azido-functionalized zwitterionic bottlebrush polymer (N3-ZBP) using a "grafting-from" strategy involving RAFT and ATRP methods was synthesized, and a trans-cyclooctene (TCO) moiety was introduced at the polymer end through the strain-promoted azide-alkyne click (SPAAC) reaction. The subsequent coupling between TCO-incorporated bottlebrush polymer and tetrazine-labeled UOX using a fast and safe bioorthogonal reaction, inverse electron demand Diels-Alder (IEDDA), led to the formation of UOX-ZBP conjugates with a 52% yield. Importantly, the enzymatic activity of UOX remained unaffected following polymer conjugation, suggesting a minimal change in the folded structure of UOX. Moreover, UOX-ZBP conjugates exhibited enhanced proteolytic resistance and reduced antibody binding, compared to UOX-wild type. Overall, the present findings reveal an efficient and straightforward route for synthesizing protein-bottlebrush polymer conjugates without compromising the enzymatic activity while substantially reducing proteolytic degradation and antibody binding.


Assuntos
Química Click , Reação de Cicloadição , Polímeros , Urato Oxidase , Urato Oxidase/química , Química Click/métodos , Polímeros/química , Ciclo-Octanos/química , Humanos , Azidas/química , Alcinos/química
4.
Bioorg Med Chem ; 103: 117681, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38492541

RESUMO

This article includes a thorough examination of the inhibitory potential of quinoline-based drugs on cancer cells, as well as an explanation of their modes of action. Quinoline derivatives, due to their various chemical structures and biological activity, have emerged as interesting candidates in the search for new anticancer drugs. The review paper delves into the numerous effects of quinoline-based chemicals in cancer progression, including apoptosis induction, cell cycle modification, and interference with tumor-growth signaling pathways. Mechanistic insights on quinoline derivative interactions with biological targets enlightens their therapeutic potential. However, obstacles such as poor bioavailability, possible off-target effects, and resistance mechanisms make it difficult to get these molecules from benchside to bedside. Addressing these difficulties might be critical for realizing the full therapeutic potential of quinoline-based drugs in cancer treatment.


Assuntos
Antineoplásicos , Neoplasias , Quinolinas , Humanos , Antineoplásicos/química , Neoplasias/tratamento farmacológico , Morte Celular , Ciclo Celular , Quinolinas/química
5.
Mol Divers ; 27(2): 951-957, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35652975

RESUMO

Ugi-four component reaction (Ugi-4CR) is extremely attractive for diversity-oriented and step economical synthesis as evident from past applications. Here we report the synthesis of fused polycyclic ß-carboline derivatives by sequential Pictet-Spengler's and Ugi-4CR multi-component reaction followed by cascade cyclization. The post cyclisation of Ugi product provides conformationally stable heterocyclic molecule that is expected to be suitable for interaction with different biological targets. The methodology provides a simple and facile access to heterocycles embedded in polycyclic framework which otherwise seems difficult to synthesize by conventional methods. Synthesis of fused Polycyclic ß-Carboline Derivatives Using Ugi-4CR Followed by Cascade Cyclization.


Assuntos
Carbolinas , Ciclização
6.
Exp Brain Res ; 239(10): 2939-2950, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34324019

RESUMO

Traumatic brain injury (TBI) is one of the main causes of death and disability in both civilian and military population. TBI may occur via a variety of etiologies, all of which involve trauma to the head. However, the neuroprotective drugs which were found to be very effective in animal TBI models failed in phase II or phase III clinical trials, emphasizing a compelling need to review the current status of animal TBI models and therapeutic strategies. No single animal model can adequately mimic all aspects of human TBI owing to the heterogeneity of clinical TBI. However, due to the ethical limitations, it is difficult to precisely emulate the TBI mechanisms that occur in humans. Therefore, many animal models with varying severity and mechanisms of brain injury have been developed, and each model has its own pros and cons in its implementation for TBI research. These challenges pose a need for study of continued TBI mechanisms, brain injury severity, duration, treatment strategies, and optimization of animal models across the neurotrauma research community. The aim of this review is to discuss (1) causes of TBI, (2) its prevalence in military and civilian population, (3) classification and pathophysiology of TBI, (4) biomarkers and detection methods, (5) animal models of TBI, and (6) the advantages and disadvantages of each model and the species used, as well as possible treatments.


Assuntos
Lesões Encefálicas Traumáticas , Lesões Encefálicas , Animais , Biomarcadores , Encéfalo , Lesões Encefálicas Traumáticas/terapia , Modelos Animais de Doenças , Humanos
7.
Biomacromolecules ; 20(1): 546-557, 2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-30521313

RESUMO

Delivery of clinically approved nonfluorescent drugs is facing challenges because it is difficult to monitor the intracellular drug delivery without incorporating any integrated fluorescence moiety into the drug carrier. The present investigation reports the synthesis of a pH-responsive autofluorescent polymeric nanoscaffold for the administration of nonfluorescent aromatic nitrogen mustard chlorambucil (CBL) drug into the cancer cells. Copolymerization of poly(ethylene glycol) (PEG) appended styrene and CBL conjugated N-substituted maleimide monomers enables the formation of well-defined luminescent alternating copolymer. These amphiphilic brush copolymers self-organized in aqueous medium into 25-68 nm nanoparticles, where the CBL drug is enclosed into the core of the self-assembled nanoparticles. In vitro studies revealed ∼70% drug was retained under physiological conditions at pH 7.4 and 37 °C. At endolysosomal pH 5.0, 90% of the CBL was released by the pH-induced cleavage of the aliphatic ester linkages connecting CBL to the maleimide unit. Although the nascent nanoparticle (without drug conjugation) is nontoxic, the drug conjugated nanoparticle showed higher toxicity and superior cell killing capability in cervical cancer (HeLa) cells rather than in normal cells. Interestingly, the copolymer without any conventional chromophore exhibited photoluminescence under UV light irradiation due to the presence of "through-space" π-π interaction between the C═O group of maleimide unit and the adjacent benzene ring of the styrenic monomer. This property helped us intracellular tracking of CBL conjugated autofluorescent nanocarriers through fluorescence microscope imaging. Finally, the 4-(4-nitrobenzyl)pyridine (NBP) colorimetric assay was executed to examine the ability of CBL-based polymeric nanomaterials toward alkylation of DNA.


Assuntos
Antineoplásicos Alquilantes/administração & dosagem , Clorambucila/administração & dosagem , Nanoconjugados/química , Polímeros Responsivos a Estímulos/química , Antineoplásicos Alquilantes/química , Clorambucila/química , Liberação Controlada de Fármacos , Células HEK293 , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Luminescência , Células MCF-7 , Maleimidas/química , Polietilenoglicóis/química , Tensoativos/química
8.
Biomarkers ; 24(1): 1-16, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30126309

RESUMO

CONTEXT: Obstructive sleep apnoea (OSA) is a sleep respiration disorder with multiple pathophysiological risks. The study of OSA is important from a public health perspective due to increased risk of cardiovascular morbidity and metabolic disorders. OBJECTIVE: The review content contributes to amalgamate the clinico-molecular analysis of microRNAs, single-nucleotide polymorphisms (SNPs), transcriptome profiles and epigenetics in the prognosis of OSA. The conceptual focus here is to demarcate the involvement of regulatory players like miRNAs that have most probable contributions towards other changes in patients leading to clinical outcomes. METHODS: Literature survey was done by retrieving data from databases such as Google Scholar, PubMed and Science Direct. RESULTS: Abundant reports have suggested the involvement and role of biomarkers such as CRP, TNF-α, IL-6, IL-8 and CAMs but there are interspersed speculations about the involvement of epigenetics in OSA. CONCLUSIONS: miRNA and transcriptome profiling, DNA methylation and SNPs are some of the less researched aspects that aim to bridge the gap in the molecular mechanisms underlying the pathophysiology of OSA. The quest for biomarkers in OSA is now distinctly achieving new heights. In the context of diagnosis, the above mentioned epigenetic regulators are likely to emerge as viable contenders.


Assuntos
Apneia Obstrutiva do Sono , Biomarcadores , Doenças Cardiovasculares/etiologia , Humanos , Prognóstico , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/etiologia , Apneia Obstrutiva do Sono/genética
9.
Org Biomol Chem ; 17(48): 10245-10250, 2019 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-31793609

RESUMO

A general and simple metal-free protocol for expedient C-H functionalization leading to the regioselective generation of C-5 chalcogenated 8-aminoquinoline analogues in up to 90% yield at room temperature (25 °C) has been established. This methodology is an eco-friendly approach to the atom-economical utilization of diaryl/dialkyl chalcogenides for direct access to chalcogenated quinolines and is scalable to the gram scale without considerable decrease in the yield of the product. It represents a practical alternative to the existing metal-catalyzed functionalization of 8-aminoquinoline derivatives with broad functional group tolerance. The controlled experiments suggest that the reaction possibly proceeds through an ionic pathway at room temperature. Furthermore, the potentiality for the functionalization of free amines in chalcogenated-8-aminoquinolines provides an attractive perspective for further elaboration of the amine substituent through chemical manipulations. The applicability of the standardized method has been augmented through late-stage antimalarial drug diversification of primaquine analogues.


Assuntos
Aminoquinolinas/síntese química , Aminas/química , Catálise , Iodo/química , Estrutura Molecular , Oxirredução , Ácido Selênico/química , Solventes/química , Estereoisomerismo , Ácidos Sulfênicos/química
10.
Regul Toxicol Pharmacol ; 109: 104489, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31605713

RESUMO

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwideand haslimited treatment options. In view of this, zafirlukast (ZAF) was administered orally to DEN-induced HCC rats to evaluate its antineoplastic properties. ELISA, qRT-PCR and Western blot were used to determine the molecular mechanism associated with ZAF therapy for HCC. We found that HCC developed as a result of lower expression of caspases 3 and 9, but their levels returned to normal when the expression of eNOS, BAX, BAD, and Cyt C was decreased and when the expression of iNOS, Bcl-xl, and Bcl-2 was increased. Again, ZAF (80 mg/kg dose) treatment normalized the expression of caspase-mediated apoptotic factors, i.e. BAX and Bcl-2 proteins, as established through Western blot analysis. Later, 1H NMR-based serum metabolomics study revealed that levels of perturbed metabolites in DEN-induced rat serum returned to normal after ZAF administration. Altogether, the antineoplastic potential of ZAF was found to be comparable, and to some degree better, than the marketed chemotherapeutic 5-flurouracil, which may be beneficial for anti-HCC treatment from a future drug design perspective.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Compostos de Tosil/farmacologia , Animais , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/sangue , Proteínas Reguladoras de Apoptose/metabolismo , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Dietilnitrosamina/toxicidade , Ensaios de Seleção de Medicamentos Antitumorais , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Humanos , Indóis , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas Experimentais/sangue , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/metabolismo , Masculino , Metabolômica , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fenilcarbamatos , Espectroscopia de Prótons por Ressonância Magnética , Ratos , Sulfonamidas , Compostos de Tosil/uso terapêutico
11.
Microcirculation ; 25(3): e12441, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29356218

RESUMO

OBJECTIVE: The aim of this study was to assess, in two experiments, the safety and efficacy of the PFC emulsion Oxycyte as an oxygen therapeutic for TBI to test the hypothesis that early administration of this oxygen-carrying fluid post-TBI would improve brain tissue oxygenation (Pbt O2 ). METHODS: The first experiment assessed the effects of Oxycyte on cerebral vasoactivity in healthy, uninjured rats using intravital microscopy. The second experiment investigated the effect of Oxycyte on cerebral Pbt O2 using the PQM in TBI model. Animals in the Oxycyte group received a single injection of Oxycyte (6 mL/kg) shortly after TBI, while NON animals received no treatment. RESULTS: Oxycyte did not cause vasoconstriction in small- (<50 µm) or medium- (50-100 µm) sized pial arterioles nor did it cause a significant change in blood pressure. Treatment with Oxycyte while breathing 100% O2 did not improve Pbt O2 . However, in rats ventilated with ~40% O2 , Pbt O2 improved to near pre-TBI values within 105 minutes after Oxycyte injection. CONCLUSIONS: Although Oxycyte did not cause cerebral vasoconstriction, its use at the dose tested while breathing 100% O2 did not improve Pbt O2 following TBI. However, Oxycyte treatment while breathing a lower enriched oxygen concentration may improve Pbt O2 after TBI.


Assuntos
Lesões Encefálicas Traumáticas/terapia , Fluorocarbonos/uso terapêutico , Oxigênio/sangue , Animais , Arteríolas/fisiologia , Encéfalo/metabolismo , Circulação Cerebrovascular , Microscopia Intravital , Oxigênio/administração & dosagem , Ratos , Vasoconstrição/efeitos dos fármacos
12.
Chemistry ; 23(52): 12917-12923, 2017 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-28683158

RESUMO

A one-dimensional nanostructure with sp3 -hybridized carbon atoms, namely, poly[5]asterane (PA), is predicted by means of electronic structure calculations and reactive molecular dynamics simulations. Thermochemical analysis based on homodesmotic reactions showed that the formation of poly[5]asterane is more favorable than that of polytriangulane and comparable to that of polytwistane. A plane-wave DFT approach gave a computed Young's modulus of about 0.84 TPa, which is quite promising and comparable to those of other sp3 -hybridized nanothreads. Simulations of the desorption of hydrogen atoms from PA showed a high activation energy (Ea ≈52 kcal mol-1 ), which again indicates substantial chemical stability. Interestingly, PA was shown to exhibit auxetic behavior (negative Poisson's ratio). Thus, PA is advocated as a new mechanically and chemically stable nanothread with exotic auxetic behavior.

13.
J Phys Chem A ; 121(40): 7494-7502, 2017 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-28926700

RESUMO

Intermolecular energy transfer for the vibrationally excited propylbenzene cation (C9H12+) in a helium bath was studied with chemical dynamics simulations. The bond energy bond order relationship and electronic structure calculations were used to develop an intramolecular potential for C9H12+. Spin component scaled MP2/6-311++G** calculations were used to develop an intermolecular potential for He + C9H12+. The He + He intermolecular potential was determined from a previous explicitly correlated Gaussian electronic structure calculation. For the simulations, C9H12+ was prepared with a 100.1 kcal/mol excitation energy to compare with experiment. The average energy transfer from C9H12+, ⟨ΔEc⟩, decreased as C9H12+ was vibrationally relaxed and for the initial excitation energy ⟨ΔEc⟩ = 0.64 kcal/mol. This result agrees well with the experimental ⟨ΔEc⟩ value of 0.51 ± 0.26 kcal/mol for collisions of He with the ethylbenzene cation. The ⟨ΔEc⟩ value found for He + C9H12+ collisions is compared with reported values of ⟨ΔEc⟩ for He colliding with other molecules.

14.
Water Sci Technol ; 76(11-12): 3368-3378, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29236016

RESUMO

This study reports adsorptive removal of Cr(VI) by magnetic manganese ferrite and manganese oxide nano-particles (MnF-MO-NPs) composite from aqueous media. The X-ray diffraction pattern of MnF-MO-NPs revealed a polycrystalline nature with nanoscale crystallite size. The prepared adsorbent with high Brunauer-Emmett-Teller specific surface area of 100.62 m2/g and saturation magnetization of 30.12 emu/g exhibited maximum Cr(VI) removal at solution pH 2.0 and was easily separated from water under an external magnetic field. Adsorption capacity as much as 91.24 mg/g is reported and electrostatic interaction between positively charged adsorbent surface and anionic metal ion species is the main driving force in this adsorption. Adsorption experimental data followed Langmuir isotherm and second order kinetics. Partial involvement of intra-particle diffusion was also observed due to the mesoporous nature of MnF-MO-NPs. The thermodynamic studies revealed that the process was favorable, spontaneous and exothermic in nature. An artificial neural network model was developed for accurate prediction of Cr(VI) ions removal with minimum mean squared error (MSE) of 15.4 × 10-4 and maximum R2 of 0.98. Owing to large surface to volume ratio, advantage of easy magnetic separation, and high adsorption capacity towards Cr(VI), the reported MnF-MO-NPs appear to be a potential candidate in Cr(VI) contaminated wastewater remediation.


Assuntos
Cromo/química , Compostos Férricos/química , Compostos de Manganês/química , Nanopartículas Metálicas , Redes Neurais de Computação , Óxidos/química , Poluentes Químicos da Água/química , Adsorção , Difusão , Concentração de Íons de Hidrogênio , Íons , Cinética , Magnetismo , Termodinâmica , Eliminação de Resíduos Líquidos , Águas Residuárias/química , Água/química , Purificação da Água , Difração de Raios X
15.
Microvasc Res ; 107: 83-90, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27287870

RESUMO

Sanguinate, a polyethylene glycol-conjugated carboxyhemoglobin, was investigated for cerebral vasoactivity in healthy male Sprague-Dawley rats (Study 1) and for its ability to increase brain tissue oxygen pressure (PbtO2) after controlled cortical impact (CCI) - traumatic brain injury (TBI) (Study 2). In both studies ketamine-acepromazine anesthetized rats were ventilated with 40% O2. In Study 1, a cranial window was used to measure the diameters of medium - (50-100µm) and small-sized (<50µm) pial arterioles before and after four serial infusions of Sanguinate (8mL/kg/h, cumulative 16mL/kg IV), volume-matched Hextend, or normal saline. In Study 2, PbtO2 was measured using a phosphorescence quenching method before TBI, 15min after TBI (T15) and then every 10min thereafter for 155min. At T15, rats received either 8mL/kg IV Sanguinate (40mL/kg/h) or no treatment (saline, 4mL/kg/h). Results showed: 1) in healthy rats, percentage changes in pial arteriole diameter were the same among the groups, 2) in TBI rats, PbtO2 decreased from 36.5±3.9mmHg to 19.8±3.0mmHg at T15 in both groups after TBI and did not recover in either group for the rest of the study, and 3) MAP increased 16±4mmHg and 36±5mmHg after Sanguinate in healthy and TBI rats, respectively, while MAP was unchanged in control groups. In conclusion, Sanguinate did not cause vasoconstriction in the cerebral pial arterioles of healthy rats but it also did not acutely increase PbtO2 when administered after TBI. Sanguinate was associated with an increase in MAP in both studies.


Assuntos
Arteríolas/efeitos dos fármacos , Lesões Encefálicas Traumáticas/tratamento farmacológico , Carboxihemoglobina/farmacologia , Circulação Cerebrovascular/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Oxigênio/metabolismo , Pia-Máter/irrigação sanguínea , Substitutos do Plasma/farmacologia , Polietilenoglicóis/farmacologia , Animais , Pressão Arterial/efeitos dos fármacos , Arteríolas/metabolismo , Arteríolas/fisiopatologia , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/fisiopatologia , Carboxihemoglobina/análogos & derivados , Carboxihemoglobina/toxicidade , Modelos Animais de Doenças , Derivados de Hidroxietil Amido/farmacologia , Masculino , Microcirculação/efeitos dos fármacos , Substitutos do Plasma/toxicidade , Polietilenoglicóis/toxicidade , Ratos Sprague-Dawley , Fatores de Tempo , Vasoconstrição/efeitos dos fármacos
16.
Macromol Rapid Commun ; 37(13): 1015-20, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27159378

RESUMO

Recently, polymer drug conjugates (PDCs) have attracted considerable attention in the treatment of cancer. In this work, a simple strategy has been developed to make PDCs of an antitumor alkylating agent, chlorambucil, using a biocompatible disulphide linker. Chlorambucil-based chain transfer agent was used to prepare various homopolymers and block copolymers in a controlled fashion via reversible addition-fragmentation chain transfer polymerization. Chlorambucil conjugated block copolymer, poly(polyethylene glycol monomethyl ether methacrylate)-b-poly(methyl methacrylate), formed nanoaggregates in aqueous solutions, which are characterized by dynamic light scattering and field emission-scanning electron microscopy. Finally, the simplicity of the design is exemplified by performing a release study of chlorambucil under reducing condition by using D,L-dithiothreitol.


Assuntos
Antineoplásicos Alquilantes/química , Clorambucila/química , Sistemas de Liberação de Medicamentos , Polímeros/química
17.
Chemistry ; 20(21): 6542-51, 2014 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-24715433

RESUMO

Metal-metal singly-bonded diruthenium complexes, bridged by naphthyridine-functionalized N-heterocyclic carbene (NHC) ligands featuring a hydroxy appendage on the naphthyridine unit, are obtained in a single-pot reaction of [Ru2(CH3COO)2(CO)4] with 1-benzyl-3-(5,7-dimethyl-1,8-naphthyrid-2-yl)imidazolium bromide (BIN⋅HBr) or 1-isopropyl-3-(5,7-dimethyl-1,8-naphthyrid-2-yl)imidazolium bromide (PIN⋅HBr), TlBF4, and substituted benzaldehyde containing an electron-withdrawing group. The modified NHC-naphthyridine-hydroxy ligand spans the diruthenium unit in which the NHC carbon and hydroxy oxygen occupy the axial sites. All the synthesized compounds catalyze acceptorless dehydrogenation of alcohols to the corresponding aldehydes in the presence of a catalytic amount of weak base 1,4-diazabicyclo[2.2.2]octane (DABCO). Further, acceptorless dehydrogenative coupling (ADHC) of the alcohol with amines affords the corresponding imine as the sole product. The substrate scope is examined with 1 (BIN, p-nitrobenzaldehyde). A similar complex [Ru2(CO)4(CH3COO)(3-PhBIN)][Br], that is devoid of a hydroxy arm, is significantly less effective for the same reaction. Neutral complex 1 a, obtained by deprotonation of the hydroxy arm in 1, is found to be active for the ADHC of alcohols and amines under base-free conditions. A combination of control experiments, deuterium labeling, kinetic Hammett studies, and DFT calculations support metal-hydroxyl/hydroxide and metal-metal cooperation for alcohol activation and dehydrogenation. The bridging acetate plays a crucial role in allowing ß-hydride elimination to occur. The ligand architecture on the diruthenium core causes rapid aldehyde extrusion from the metal coordination sphere, which is responsible for exclusive imine formation.

18.
Org Biomol Chem ; 12(21): 3459-69, 2014 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-24752626

RESUMO

A newsworthy class of carboxylate esters based on the (benzo[a]acridin-12-yl)methyl (BAM) chromophore has been shown to perform dual functions as a "pH sensitive fluorescent probe" and a "phototrigger" for acids. The photophysical properties of all the BAM ester conjugates were investigated and found to be highly sensitive to solvent polarity, H-bonding capability and pH of the environment. On irradiation using UV light (≥410 nm), BAM ester conjugates underwent heterolytic cleavage of C-O bonds resulting in efficient release of carboxylic and amino acids. Interestingly, the newly synthesized BAM chromophore was also explored for the construction of a drug delivery system (DDS). In the current DDS, the BAM chromophore plays two important roles: (i) a "fluorophore" for cell imaging and (ii) a "phototrigger" for the drug release. In vitro biological studies revealed that the newly developed BAM based DDS has a good biocompatibility, cellular uptake properties and efficient photoregulated anticancer drug release ability.


Assuntos
Acridinas/síntese química , Acridinas/farmacologia , Ésteres/síntese química , Ésteres/farmacologia , Corantes Fluorescentes/síntese química , Luz , Processos Fotoquímicos , Acridinas/química , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Clorambucila/síntese química , Clorambucila/química , Clorambucila/farmacologia , Sistemas de Liberação de Medicamentos , Ésteres/química , Corantes Fluorescentes/química , Células HeLa , Humanos , Ligação de Hidrogênio/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Simulação de Acoplamento Molecular , Imagem Molecular , Fotólise/efeitos dos fármacos , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Fatores de Tempo
19.
J Mol Graph Model ; 129: 108730, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38377793

RESUMO

Inorganic binders like bentonite, used for pelletization of low-grade iron ore, generate iron ore slimes with comparatively high silica and alumina content necessitating extra steps for their removal during iron making process. This demands the usage of organic binders as full or partial replacement of bentonite for iron ore pelletization. In this work, adsorption of organic binders with saccharides skeleton and -H, -OH, -CH2OH and -CH2CH2OH as polar substituents, on goethite surface was studied using density functional theory, molecular dynamics and machine learning. It was observed that adsorption energy of binders on goethite surface had weak dependence on number of hydrogen bonds between them. With this favorable interaction in mind, a library containing 64 organic binders was constructed and adsorption energy of 30 of these binders was computed using molecular dynamics, followed by training of a linear regression model, which was then used to predict the adsorption energy of rest of the binders in the library. It was found that the introduction of -CH2CH2OH at R2 position resulted in statistically significant higher adsorption energy. Binder34 and Binder44 were identified as viable candidates for both goethite and hematite ore pelletization and adsorption of their n-mers on goethite and hematite surfaces was also quantified.


Assuntos
Bentonita , Compostos Férricos , Compostos de Ferro , Minerais , Bentonita/química , Compostos de Ferro/química , Ferro/química , Adsorção
20.
J Med Chem ; 67(13): 11069-11085, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38913981

RESUMO

Breast adenocarcinoma ranks high among the foremost lethal cancers affecting women globally, with its triple-negative subtype posing the greatest challenge due to its aggressiveness and resistance to treatment. To enhance survivorship and patients' quality of life, exploring advanced therapeutic approaches beyond conventional chemotherapies is imperative. To address this, innovative nanoscale drug delivery systems have been developed, offering precise, localized, and stimuli-triggered release of anticancer agents. Here, we present perylenemonoimide nanoparticle-based vehicles engineered for deep-red light activation, enabling direct chlorambucil release. Synthesized via the reprecipitation technique, these nanoparticles were thoroughly characterized. Light-induced drug release was monitored via spectroscopic and reverse-phase HPLC. The efficacy of the said drug delivery system was evaluated in both two-dimensional and three-dimensional spheroidal cancer models, demonstrating significant tumor regression attributed to apoptotic cell death induced by efficient drug release within cells and spheroids. This approach holds promise for advancing targeted breast cancer therapy, enhancing treatment efficacy and minimizing adverse effects.


Assuntos
Antineoplásicos , Neoplasias da Mama , Esferoides Celulares , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Esferoides Celulares/efeitos dos fármacos , Liberação Controlada de Fármacos , Luz , Clorambucila/química , Clorambucila/farmacologia , Clorambucila/uso terapêutico , Nanopartículas/química , Linhagem Celular Tumoral , Apoptose/efeitos dos fármacos , Fótons , Perileno/análogos & derivados , Perileno/química , Perileno/farmacologia , Perileno/uso terapêutico , Luz Vermelha
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