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1.
Arch Toxicol ; 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38795134

RESUMO

The exploration of natural products as potential agents for cancer treatment has garnered significant attention in recent years. In this comprehensive review, we delve into the diverse array of natural compounds, including alkaloids, carbohydrates, flavonoids, lignans, polyketides, saponins, tannins, and terpenoids, highlighting their emerging roles in cancer therapy. These compounds, derived from various botanical sources, exhibit a wide range of mechanisms of action, targeting critical pathways involved in cancer progression such as cell proliferation, apoptosis, angiogenesis, and metastasis. Through a meticulous examination of preclinical and clinical studies, we provide insights into the therapeutic potential of these natural products across different cancer types. Furthermore, we discuss the advantages and challenges associated with their use in cancer treatment, emphasizing the need for further research to optimize their efficacy, pharmacokinetics, and delivery methods. Overall, this review underscores the importance of natural products in advancing cancer therapeutics and paves the way for future investigations into their clinical applications.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38415097

RESUMO

Objective: This comprehensive literature scoping review outlines available infection prevention and control (IPC) methods for viral-mediated gene therapies and provides one IPC strategy for the healthcare setting based on a single-center recommendation. Methods: A team of experts in pharmacy, healthcare epidemiology, and biosafety with experience in viral-mediated gene therapy was assembled within a pediatric hospital to conduct a comprehensive literature scoping review. The comprehensive review included abstracts and full-text articles published since 2009 and utilized prespecified search terms of the five viral vectors of interest: adenovirus (AV), retrovirus (RV), adeno-associated virus (AAV), lentivirus (LV), and herpes simplex virus (HSV). Case reports, randomized controlled trials, and bench research studies were all included, while systematic reviews were excluded. Results: A total of 4473 case reports, randomized control trials, and benchtop research studies were identified using the defined search criteria. Chlorine compounds were found to inactivate AAV and AV, while alcohol-based disinfectants were ineffective. There was a relative paucity of studies investigating surface-based disinfection for HSV, however, alcohol-based disinfectants were effective in one study. Ultraviolent irradiation was also found to inactivate HSV in numerous studies. No studies investigated disinfection for LV and RV vectors. Conclusions: The need to define IPC methods is high due to the rapid emergence of viral-mediated gene therapies to treat rare diseases, but published clinical guidance remains scarce. In the absence of these data, our center recommends a 1:10 sodium hypochlorite solution in clinical and academic environments to ensure complete germicidal activity of viral-mediated gene therapies.

4.
J Mater Chem B ; 11(40): 9697-9711, 2023 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-37789772

RESUMO

Additive manufacturing enables the fabrication of patient-specific implants of complex geometries. Although selective laser melting (SLM) of 316L stainless steel (SS) is well established, post-processing is essential to preparing high-performance biomedical implants. The goal of this study was to investigate surface mechanical attrition treatment (SMAT) as a means to enhance the electrochemical, biomechanical, and biological performances of 316L SS fabricated by SLM in devices for the repair of bone tissues. The SMAT conditions were optimized to induce surface nanocrystallization on the additively manufactured samples. SMAT resulted in a thicker oxide layer, which provided corrosion resistance by forming a passive layer. The fretting wear results showed that the rate of wear decreased after SMAT owing to the formation of a harder nanostructured layer. Surface modification of the alloy by SMAT enhanced its ability to support the attachment and proliferation of pre-osteoblasts in vitro. The study of the response in vivo to the additively manufactured alloy in a critical-sized cranial defect murine model revealed enhanced interactions with the cellular components after the alloy was subjected to SMAT without inducing any adverse immune response. Taken together, the results of this work establish SMAT of additively manufactured metallic implants as an effective strategy for engineering next-generation, high-performance medical devices for orthopedics and craniomaxillofacial applications.


Assuntos
Próteses e Implantes , Aço Inoxidável , Humanos , Animais , Camundongos , Aço Inoxidável/química , Óxidos
5.
Plant Mol Biol ; 113(4-5): 219-236, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37898975

RESUMO

Boswellia tree bark exudes oleo-gum resin in response to wounding, which is rich in terpene volatiles. But, the molecular and biochemical basis of wound-induced formation of resin volatiles remains poorly understood. Here, we combined RNA-sequencing (RNA-seq) and metabolite analysis to unravel the terpene synthase (TPS) family contributing to wound-induced biosynthesis of resin volatiles in B. serrata, an economically-important Boswellia species. The analysis of large-scale RNA-seq data of bark and leaf samples representing more than 600 million sequencing reads led to the identification of 32 TPSs, which were classified based on phylogenetic relationship into various TPSs families found in angiosperm species such as TPS-a, b, c, e/f, and g. Moreover, RNA-seq analysis of bark samples collected at 0-24 h post-wounding shortlisted 14 BsTPSs that showed wound-induced transcriptional upregulation in bark, suggesting their important role in wound-induced biosynthesis of resin volatiles. Biochemical characterization of a bark preferentially-expressed and wound-inducible TPS (BsTPS2) in vitro and in planta assays revealed its involvement in resin terpene biosynthesis. Bacterially-expressed recombinant BsTPS2 catalyzed the conversion of GPP and FPP into (S)-( +)-linalool and (E)-(-)-nerolidol, respectively, in vitro assays. However, BsTPS2 expression in Nicotiana benthamiana found that BsTPS2 is a plastidial linalool synthase. In contrast, cytosolic expression of BsTPS2 did not form any product. Overall, the present work unraveled a suite of TPSs that potentially contributed to the biosynthesis of resin volatiles in Boswellia and biochemically characterized BsTPS2, which is involved in wound-induced biosynthesis of (S)-( +)-linalool, a monoterpene resin volatile with a known role in plant defense.


Assuntos
Alquil e Aril Transferases , Boswellia , Humanos , Boswellia/genética , Boswellia/metabolismo , Filogenia , Terpenos/metabolismo , Alquil e Aril Transferases/genética
7.
Cell Signal ; 111: 110876, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37640193

RESUMO

Selective initiation of programmed cell death in cancer cells than normal cells is reflected as an attractive chemotherapeutic strategy. In the current study, a series of synthetic bis-coumarin derivatives were synthesized possessing reactive oxygen species (ROS) modulating functional groups and examined in four cancerous and two normal cell lines for their cytotoxic ability using MTT assay. Among these compounds, 3 l emerged as the most promising derivative in persuading apoptosis in human renal carcinoma cells (SKRC-45) among diverse cancer cell lines. 3 l causes significantly less cytotoxicity to normal kidney cells compared to cisplatin. This compound was able to induce apoptosis and cell-cycle arrest by modulating the p53 mediated apoptotic pathways via the generation of ROS, decreasing mitochondrial membrane potential, and causing DNA fragmentation. Unlike cisplatin, the 3 l derivative was found to inhibit the nuclear localisation of NF-κB in SKRC-45 cells. It was also found to reduce the proliferation, survival and migration ability of SKRC-45 cells by downregulating COX-2/ PTGES2 cascade and MMP-2. In an in vivo tumor model, 3 l showed an anticancer effect by reducing the mean tumor mass, volume and inducing caspase-3 activation, without affecting kidney function. Further studies are needed to establish 3 l as a promising anti-cancer drug candidate.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Espécies Reativas de Oxigênio/metabolismo , Cisplatino/farmacologia , Antineoplásicos/farmacologia , Apoptose , Cumarínicos/farmacologia , Proliferação de Células , Linhagem Celular Tumoral
8.
Biotechnol Adv ; 68: 108214, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37478981

RESUMO

Triterpenoids are among the most assorted class of specialized metabolites found in all the taxa of living organisms. Triterpenoids are the leading active ingredients sourced from plant species and are utilized in pharmaceutical and cosmetic industries. The triterpenoid precursor 2,3-oxidosqualene, which is biosynthesized via the mevalonate (MVA) pathway is structurally diversified by the oxidosqualene cyclases (OSCs) and other scaffold-decorating enzymes such as cytochrome P450 monooxygenases (P450s), UDP-glycosyltransferases (UGTs) and acyltransferases (ATs). A majority of the bioactive triterpenoids are harvested from the native hosts using the traditional methods of extraction and occasionally semi-synthesized. These methods of supply are time-consuming and do not often align with sustainability goals. Recent advancements in metabolic engineering and synthetic biology have shown prospects for the green routes of triterpenoid pathway reconstruction in heterologous hosts such as Escherichia coli, Saccharomyces cerevisiae and Nicotiana benthamiana, which appear to be quite promising and might lead to the development of alternative source of triterpenoids. The present review describes the biotechnological strategies used to elucidate complex biosynthetic pathways and to understand their regulation and also discusses how the advances in triterpenoid pathway engineering might aid in the scale-up of triterpenoid production in engineered hosts.


Assuntos
Triterpenos , Plantas/metabolismo , Biotecnologia/métodos , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Engenharia Metabólica/métodos , Saccharomyces cerevisiae/metabolismo
9.
Nanoscale ; 15(23): 10004-10016, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37232217

RESUMO

The essences of the quenching and partitioning (Q&P) process are to stabilize the finely divided retained austenite (RA) via carbon (C) partitioning from supersaturated martensite during partitioning. Competitive reactions, i.e., transition carbide precipitation, C segregation, and decomposition of austenite, might take place concurrently during partitioning. In order to maintain the high volume fraction of RA, it is crucial to suppress the carbide precipitation sufficiently. Since silicon (Si) in the cementite θ (Fe3C) is insoluble, alloying Si in adequate concentrations prolongs its precipitation during the partitioning step. Consequently, C partitioning facilitates the desired chemical stabilization of RA. To elucidate the mechanisms of formation of transition η (Fe2C) carbides as well as cementite, θ (Fe3C), besides the transformation of transition carbides to more stable θ during the quenching and partitioning (Q&P) process, samples of 0.4 wt% C steels tailored with different Si contents were extensively characterized for microstructural evolution at different partitioning temperatures (TP) using high resolution transmission electron microscopy (HR-TEM) and three-dimensional atom probe tomography (3D-APT). While 1.5 wt% Si in the steel allowed only the formation of η carbides even at a high TP of 300 °C, reduction in Si content to 0.75 wt% only partially stabilized η carbides, allowing limited η → θ transformation. With 0.25 wt% Si, only θ was present in the microstructure, suggesting a η → θ transition during the early partitioning stage, followed by coarsening due to enhanced growth kinetics at 300 °C. Although η carbides precipitated in martensite under paraequilibrium conditions at 200 °C, θ carbides precipitated under negligible partitioning local equilibrium conditions at 300 °C. Competition with the formation of orthorhombic η and θ precipitation further examined via ab initio (density functional theory, DFT) computation and a similar probability of formation/thermodynamic stability were obtained. With an increase in Si concentration, the cohesive energy decreased when Si atoms occupied C positions, indicating decreasing stability. Overall, the thermodynamic prediction was in accord with the HR-TEM and 3D-APT results.


Assuntos
Ligas , Aço , Silício , Compreensão
10.
Int J Pharm ; 631: 122555, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36586636

RESUMO

Cancer is a disease of global importance. In order to mitigate conventional chemotherapy-related side effects, phytochemicals with inherent anticancer efficacy have been opted. However, the use of nanotechnology is essential to enhance the bioavailability and therapeutic efficacy of these phytochemicals. Herein, we have formulated folic acid conjugated polyacrylic acid capped mesoporous silica nanoparticles (∼47.6 nm in diameter) for pH-dependent targeted delivery of chrysin to breast cancer (MCF-7) cells. Chrysin loaded mesoporous silica nanoparticles (Chr- mSiO2@PAA/FA) have been noted to induce apoptosis in MCF-7 cells through oxidative insult and mitochondrial dysfunction with subsequent G1 arrest. Further, in tumor bearing mice, intravenous incorporation of Chr-mSiO2@PAA/FA has been noticed to enhance the anti-neoplastic effects of chrysin via tumor site-specific accumulation. Enhanced cytotoxicity of chrysin contributed towards in vivo tumor regression, restoration of normalized tissue architecture and maintenance of healthy body weight. Besides, no serious systemic toxicity was manifested in response to Chr-mSiO2@PAA/FA administration in vivo. Thus, the study evokes about the anticancer potentiality of chrysin and its increased therapeutic activity via incorporation into folic acid conjugated mesoporous silica nanoparticles, which may hold greater impact in field of future biomedical research.


Assuntos
Nanopartículas , Neoplasias , Camundongos , Animais , Sistemas de Liberação de Medicamentos , Dióxido de Silício , Ácido Fólico , Concentração de Íons de Hidrogênio , Portadores de Fármacos , Porosidade
11.
Life Sci ; 307: 120876, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35961595

RESUMO

Asiatic acid (AA), an aglycone of pentacyclic triterpene glycoside, obtained from the leaves of Centella asiatica exerts anticancer effects by inhibiting cellular proliferation and inducing apoptosis in a wide range of carcinogenic distresses. However, its chemotherapeutic efficacy is dampened by its low bioavailability. Polymeric nanoparticles (NPs) exhibit therapeutic efficacy and compliance by improving tissue penetration and lowering toxicity. Thus, to increase the therapeutic effectiveness of AA in the treatment of breast cancer, AA-loaded poly lactic-co-glycolic acid (PLGA) NPs (AA-PLGA NPs) have been formulated. The AA-PLGA NPs were characterized on the basis of their average particle size, zeta potential, electron microscopic imaging, drug loading, and entrapment efficiency. The NPs exhibited sustained drug release profile in vitro. Developed NPs exerted dose-dependent cytotoxicity to MCF-7 and MDA-MB-231 cells without damaging normal cells. The pro-oxidant and pro-apoptotic properties of AA-PLGA NPs were determined by the study of the cellular levels of SOD, CAT, GSH-GSSG, MDA, protein carbonylation, ROS, mitochondrial membrane potential, and FACS analyses on MCF-7 cells. Immunoblotting showed that AA-PLGA NPs elicited an intrinsic pathway of apoptosis in MCF-7 cells. In vivo studies on female BALB/c mice exhibited reduced volume of mammary pad tumor tissues and augmented expression of caspase-3 when administered with AA-PLGA NPs. No systemic adverse effect of AA-PLGA NPs was observed in our studies. Thus, AA-PLGA NPs can act as an efficient drug delivery system against breast cancer.


Assuntos
Antineoplásicos/farmacologia , Nanopartículas , Neoplasias , Animais , Caspase 3 , Linhagem Celular Tumoral , Portadores de Fármacos , Feminino , Dissulfeto de Glutationa , Glicolatos , Glicosídeos , Camundongos , Tamanho da Partícula , Triterpenos Pentacíclicos/farmacologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Espécies Reativas de Oxigênio , Superóxido Dismutase
12.
Toxicol Rep ; 9: 961-969, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35875254

RESUMO

Recently, different natural bioactive compounds have been used as anticancer agents for their various therapeutic benefits and non-toxic nature to other organs. However, they have various restrictions in preclinical and clinical studies due to their non-targeting nature and insufficient bioavailability. As a result, a zinc oxide nanoparticle (ZnO) based drug delivery medium was constructed which has good bio-compatibility and bio-degradability. It also displays cancer cell-specific drug delivery in a targeted and controlled way. In the present study, phenylboronic acid (PBA) tagged ZnO nanoparticles (ZnO-PBA) was fabricated and in the next step, chrysin (a natural bio-active molecule) was loaded to it to form the nanoconjugate (ZnO-PBA-Chry). Different characterization techniques were used to confirm the successful fabrication of ZnO-PBA-Chry. PBA-tagging to the nanoparticle helps in targeted delivery of chrysin in lung cancer cells (A549) as PBA binds with sialic acid receptors which are over-expressed on the surface of A549 cells. As ZnO dissociates in acidic pH, it shows stimuli-responsive release of chrysin in tumor microenvironment. Application of ZnO-PBA-Chry nanohybrid in lung cancer cell line A549 caused oxidative stress mediated intrinsic cell death and cell cycle arrest. ZnO-PBA-Chry downregulated MMP-2 and VE-Cadherin, thereby inhibiting metastasis and the invasive property of A549 cells.

13.
J Biochem Mol Toxicol ; 36(10): e23163, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35844137

RESUMO

The renin-angiotensin system (RAS) is an important regulator in pulmonary physiology. In our study, we identified the efficacy of melatonin to control the RAS in cadmium (Cd) induced chronic lung injury in a mouse model. Swiss albino mice exposed to CdCl2 intraperitoneally (I.P.) (1 mg/kg b.w.; 12 weeks) showed increased release of lactate dehydrogenase in bronchoalveolar lavage fluid, generating reactive oxygen species, impaired antioxidant enzymes function, and disrupted alveolar structure along with increased expression of Angiotensin-II (Ang-II) in lung tissue. Cd-induced angiotensin-converting enzyme-2-Ang-II axis imbalance triggered the onset of Ang-II induced tumour necrosis factor alpha  (TNF-α) mediated necroptosis by upregulating the signalling molecules RIP-1, RIP-3, and p-mixed lineage kinase domain-like. In an in vitro study, colocalization of Ang-II-RIP-3 molecule in Cd intoxicated L-132 cells (human alveolar epithelial cell line), as well as pretreatment of Cd exposed cells with the inhibitor's captopril (10 µM), necrostatin-1 (50 µM), and etanercept (5 µg/ml) indicated TNF-α induced necroptotic cell death via activation of the key molecule, Ang-II. Moreover, Ang-II disrupted the alveolar-capillary barrier by decreasing tight junctional proteins (zonula occludens-1 and occludin) and endothelial VE-cadherin expression. The use of human umbilical vein endothelial cells as a model of junctional protein-expressing cells showed that captopril pretreatment (25 µM) restored VE-cadherin expression in Cd-treated human umbilical vein endothelial cells. In CdCl2 intoxicated mice, melatonin pretreatment (10 mg/kg b.w.; 12 weeks, I.P.) inhibited inflammatory mediators (TNF-α, interleukin [IL]-1ß, and IL-6) release and effectively suppressed (Cd-induced) Ang-II mediated necroptotic cell death and alveolar-capillary breaching due to Cd toxicity.


Assuntos
Lesão Pulmonar , Melatonina , Edema Pulmonar , Angiotensina II/farmacologia , Animais , Antioxidantes , Cádmio/toxicidade , Captopril/farmacologia , Células Endoteliais/metabolismo , Etanercepte , Humanos , Interleucina-6/metabolismo , Lactato Desidrogenases , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/tratamento farmacológico , Camundongos , Necroptose , Ocludina , Edema Pulmonar/induzido quimicamente , Edema Pulmonar/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
14.
Int. j. high dilution res ; 21: 18-26, June 20, 2022.
Artigo em Inglês | LILACS, HomeoIndex - Homeopatia | ID: biblio-1396375

RESUMO

High dilutions (HD) of drugs used in homeopathy are mostly too dilute to contain original drug molecules. But evidences support their specific biological and therapeutic effects. The reason behind this is thought to be water structure characteristic of the original drug. Spectroscopic studies indicate that the specific water structure in HDs can be resolved into free water molecules, hydrogen bonding strength of water hydroxyl, number of hydrogen bonds and clathrate hydrate crystals (CHC). HDs are prepared in EtOH water solution by serial dilution and mechanical agitation, and are called potencies. The objective of the present study is to further confirm the presence of CHCs in the two potencies of three drugs. Electronic spectra of the HDs of the potencies indicate two broad peaks and marked difference in intensities of absorption. Furior Transform Infrared (FT-IR) spectra of the test potencies and their control show difference in intensity shift and contour shape of OH stretching and bending bands. All the experimental data indicate the presence of CHCs in varying amounts in the test potencies.


Assuntos
Medicamento Homeopático , Hidrato de Cloral , Espectrofotometria Ultravioleta , Eletricidade Estática
16.
Int. j. high dilution res ; 21(2): 26-26, May 6, 2022.
Artigo em Inglês | LILACS, HomeoIndex - Homeopatia | ID: biblio-1396705

RESUMO

Drugs at high dilution (HD) produce therapeutic effect on man, animals and plants. Experimental evidence shows that free water molecules and hydrogen bond strength of OH groups constitute the physical basis of HDs which are otherwise devoid of original drug molecules. HDs are produced in aqueous EtOH by serial dilution of a substance with mechanical agitation or succussion in each step, and are called potencies. Three potencies 6 cH, 12 cH and 30 cH of two drugs Anacardium orientale and Natrum muriaticum(NaCl) and their mother tincture (MT) are used in this study. Electronic spectra of these MTs and potencies, all in 90% EtOH, were taken in the wavelength region of 190 nm ­350 nm. The objective is to find out any additional physical-chemical entities in potencies besides the aforesaid two factors. It was reported earlier that charge transfer (CT) interaction accompanies potentization of drugs. This study focused on the CT interaction. The results indicate that spectral pattern and absorbance intensities of the test samples vary from each other. Natm 6cH (absorbance 0.30 at 196.53nm), 12cH (abs. 0.06 at 196.53nm) and 30cH (abs. 1.32 at 196.5nm). Anac 6cH (abs. 0.33 at 203nm), 12cH (abs. 0.61 at 208nm) and 30cH (abs. 0.09 at 200.67nm). The spectrum of each potency shows two peaks. The 2nd peak at higher wave length belongs to CT interaction. Anac 6cH suc, 7cH unsuc. Insersections at 197.14nm with abs. 0.05, and 290nm with abs. 0.01. Anac 12cH suc, 13cH unsuc. Intersections at 196.93nm with abs. 0.06, and 273nm with abs. 0.00. Anac 30cH suc, 31cH unsuc. Intersections at 194.42nm with abs. -0.05, 238.03nm with abs. -0.01, 252.15nm with abs. -0.002, and 261nm with abs. 0.004. Natm 6cH suc, 7cH unsuc. Intersection at 199.44nm with Abs -0.11. Natm 12cH suc, 13cH unsuc. Instersection at 200.48nm with abs. -0.11. Natm 30cH suc, 31cH unsuc. Intersection at 204.24nm with abs. -0.08. Potentization involves CT interaction in consecutive potencies. Water and EtOH do not form a homogeneous mixture and have aggregates of EtOHand water molecules. CT interactions occur in these individual aggregates and are mostly inter molecular within EtOH or water. These aggregates vary from each other in the test samples. The spectra of test samples were analysed for margin of error (MOE). The MOE is very small (0.001-0.002%), and for this reason the difference between the spectra is significant. Besides that the intersection between consecutive spectra vary in number and position. It is concluded that water and EtOH aggregates and their relative distribution constitute additional physical-chemical basis of potencies.


Assuntos
Espectrofotometria , Escalas de Preparação , Medicamento Homeopático
17.
Life Sci ; 298: 120525, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35378139

RESUMO

AIMS: Synthesis of novel drug delivery system for targeted delivery of cuminaldehyde to breast cancer cells and the subsequent analyses of anti-neoplastic potential of the drug. MAIN METHODS: 3-carboxy-phenyl boronic acid (PBA) conjugated and polyacrylic acid (PAA) gated mesoporous silica nanoparticles (MSNs) were synthesized for the targeted delivery of cuminaldehyde (CUM) to breast cancer cells. Enhancement of anti-neoplastic effects of cuminaldehyde (4-isopropylbenzaldehyde) by the nanoconjugates was assessed. KEY FINDINGS: The anti-cancer effects of non-targeted and targeted drug-nanoconjugates were examined in vitro and in vivo. The targeted drug-nanoconjugates caused cell cycle arrest and induced the intrinsic pathway of apoptosis in MCF-7 cells through mitochondrial damage. In vivo intravenous injection of the targeted drug-nanoconjugates led to effective reduction in growth of 4 T1 induced mammary pad tumor in female BALB/c mice via augmented accumulation of cuminaldehyde. The drug-nanoconjugates did not exhibit any systemic toxicity. SIGNIFICANCE: Therefore, MSN-PBA-CUM-PAA represents a potent therapeutic model for breast cancer treatment.


Assuntos
Antineoplásicos , Neoplasias da Mama , Nanopartículas , Animais , Antineoplásicos/uso terapêutico , Benzaldeídos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Cimenos , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Camundongos , Nanoconjugados/uso terapêutico , Porosidade , Dióxido de Silício/uso terapêutico
18.
Fatigue Fract Eng Mater Struct ; 45(11): 3361-3377, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36590824

RESUMO

The influence of load ratio on the high and very high cycle fatigue (VHCF) strength of Ck45M steel processed by thermomechanical rolling integrated direct quenching was investigated. Ultrasonic fatigue tests were performed under uniaxial and torsional loading at load ratios of R = -1, 0.05, 0.3, and 0.5 with smooth specimens and specimens containing artificially introduced defects. Up to 2 × 105 cycles, failure originated from surface aluminate inclusions and pits under both loading conditions. The prevailing fracture mechanisms in the VHCF regime were interior crack initiation under uniaxial loading and surface shear crack initiation under torsional loading. The mean-stress sensitivity and the fatigue strength were evaluated using fracture mechanics approaches. Equal fatigue limits for uniaxial and torsional loading were determined considering the size of crack initiating defects and the appropriate threshold condition for Mode-I crack growth. Furthermore, the mean-stress sensitivity is independent of loading condition and can be expressed by σ w R = σ w R = - 1 · 1 - R 2 0.63 and τ w R = τ w R = - 1 · 1 - R 2 0.63 .

19.
Int. j. high dilution res ; 20(4): 29-42, Dec. 31, 2021.
Artigo em Inglês | LILACS, HomeoIndex - Homeopatia | ID: biblio-1396367

RESUMO

High dilutions (HDs) of drugs, used in Homeopathy, are prepared in aqueous EtOH (ethanol) through serial dilution accompanying mechanical agitation or succussion, and are called potencies. The potencies from the rank 12 onwards are too dilute to contain any original drug molecules. Do the potency ranks show any difference from each other? Do serial dilution and succussion contribute to the difference in potency ranks? This study aims to address these two questions. The throat swab of a Covid-19 patient was preserved and diluted with aqueous EtOH 90% to prepare the mother tincture (MT) and five different potencies of Covid named Covidinum. These potencies and their solvent media were analysed by electronic and vibrational spectroscopy. Charge transfer (CT) and proton transfer interactions occur during preparation of the potencies. The FT-IR spectra of all the test samples after normalization show difference from each other with respect to O-H stretching and bending (v2) bands. Serial dilution and succussion contribute to the observed difference in ranks and CT interactions.


Assuntos
COVID-19 , Análise Espectral
20.
Org Lett ; 23(16): 6510-6514, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34379426

RESUMO

A mild, efficient, and one-pot protocol for three-component carbosilylation of alkenes with imidazoheterocycle and silanes has been developed by merging iron(II) and visible-light photocatalysis. This C-C and C-Si bond-forming method provides functionalized organosilicon derivatives having imidazoheterocycles moieties in good yields. The reaction possibly proceeds through a radical pathway.

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