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1.
Mikrochim Acta ; 191(6): 330, 2024 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744738

RESUMO

In view of a large number of people infected with Helicobacter pylori (H. pylori) with great harm followed, there is an urgent need to develop a non-invasive, easy-to-operate, and rapid detection method, and to identify effective sterilization strategies. In this study, highly specific nanoprobes with nanozyme activity, Ag@Pt nanoparticles (NPs) with the antibody, were utilized as a novel lateral flow immunoassay (LFIA). The optical label (Ag@Pt NPs) was enhanced by the introduction of the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) and compared with a gold nanoparticles (Au NPs) optical label. Under the optimal condition, Ag@Pt-LFIA and TMB-enhanced Ag@Pt-LFIA for H. pylori were successfully established, two of which were over twofold and 100-fold more sensitive than conventional visual Au NP-based LFIA, respectively. Furthermore, Ag@Pt NPs with the antibody irradiated with NIR laser (808 nm) at a power intensity of 550 mW/cm2 for 5 min exhibited a remarkable antibacterial effect. The nanoprobes could close to bacteria through effective interactions between antibodies and bacteria, thereby benefiting photothermal sterilization. Overall, Ag@Pt NPs provide promising applications in pathogen detection and therapeutic applications.


Assuntos
Ligas , Helicobacter pylori , Nanopartículas Metálicas , Platina , Prata , Helicobacter pylori/efeitos da radiação , Helicobacter pylori/efeitos dos fármacos , Prata/química , Nanopartículas Metálicas/química , Platina/química , Ligas/química , Antibacterianos/farmacologia , Antibacterianos/química , Imunoensaio/métodos , Benzidinas/química , Ouro/química , Humanos , Esterilização/métodos , Limite de Detecção
2.
Sci Rep ; 14(1): 11025, 2024 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744861

RESUMO

Platinum-resistant phenomena in ovarian cancer is very dangerous for women suffering from this disease, because reduces the chances of complete recovery. Unfortunately, until now there are no methods to verify whether a woman with ovarian cancer is platinum-resistant. Importantly, histopathology images also were not shown differences in the ovarian cancer between platinum-resistant and platinum-sensitive tissues. Therefore, in this study, Fourier Transform InfraRed (FTIR) and FT-Raman spectroscopy techniques were used to find chemical differences between platinum-resistant and platinum-sensitive ovarian cancer tissues. Furthermore, Principal Component Analysis (PCA) and machine learning methods were performed to show if it possible to differentiate these two kind of tissues as well as to propose spectroscopy marker of platinum-resistant. Indeed, obtained results showed, that in platinum-resistant ovarian cancer tissues higher amount of phospholipids, proteins and lipids were visible, however when the ratio between intensities of peaks at 1637 cm-1 (FTIR) and at 2944 cm-1 (Raman) and every peaks in spectra was calculated, difference between groups of samples were not noticed. Moreover, structural changes visible as a shift of peaks were noticed for C-O-C, C-H bending and amide II bonds. PCA clearly showed, that PC1 can be used to differentiate platinum-resistant and platinum-sensitive ovarian cancer tissues, while two-trace two-dimensional correlation spectra (2T2D-COS) showed, that only in amide II, amide I and asymmetric CH lipids vibrations correlation between two analyzed types of tissues were noticed. Finally, machine learning algorithms showed, that values of accuracy, sensitivity and specificity were near to 100% for FTIR and around 95% for FT-Raman spectroscopy. Using decision tree peaks at 1777 cm-1, 2974 cm-1 (FTIR) and 1714 cm-1, 2817 cm-1 (FT-Raman) were proposed as spectroscopy marker of platinum-resistant.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias Ovarianas , Análise de Componente Principal , Análise Espectral Raman , Feminino , Humanos , Análise Espectral Raman/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Pessoa de Meia-Idade , Platina , Biomarcadores Tumorais , Aprendizado de Máquina , Idoso
3.
Cell Death Dis ; 15(5): 329, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38740757

RESUMO

Iron is crucial for cell DNA synthesis and repair, but an excess of free iron can lead to oxidative stress and subsequent cell death. Although several studies suggest that cancer cells display characteristics of 'Iron addiction', an ongoing debate surrounds the question of whether iron can influence the malignant properties of ovarian cancer. In the current study, we initially found iron levels increase during spheroid formation. Furthermore, iron supplementation can promote cancer cell survival, cancer spheroid growth, and migration; vice versa, iron chelators inhibit this process. Notably, iron reduces the sensitivity of ovarian cancer cells to platinum as well. Mechanistically, iron downregulates DNA homologous recombination (HR) inhibitor polymerase theta (POLQ) and relieves its antagonism against the HR repair enzyme RAD51, thereby promoting DNA damage repair to resist chemotherapy-induced damage. Additionally, iron tightly regulated by ferritin (FTH1/FTL) which is indispensable for iron-triggered DNA repair. Finally, we discovered that iron chelators combined with platinum exhibit a synergistic inhibitory effect on ovarian cancer in vitro and in vivo. Our findings affirm the pro-cancer role of iron in ovarian cancer and reveal that iron advances platinum resistance by promoting DNA damage repair through FTH1/FTL/POLQ/RAD51 pathway. Our findings highlight the significance of iron depletion therapy, revealing a promising avenue for advancing ovarian cancer treatment.


Assuntos
Reparo do DNA , Resistencia a Medicamentos Antineoplásicos , Ferro , Neoplasias Ovarianas , Rad51 Recombinase , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Ferro/metabolismo , Linhagem Celular Tumoral , Rad51 Recombinase/metabolismo , Animais , Ferritinas/metabolismo , Camundongos , Platina/farmacologia , Platina/uso terapêutico , Camundongos Nus , Oxirredutases/metabolismo
4.
Technol Cancer Res Treat ; 23: 15330338241249692, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38706262

RESUMO

PURPOSE: PIWI-interacting RNAs (piRNAs) are a type of noncoding small RNA that can interact with PIWI-like RNA-mediated gene silencing (PIWIL) proteins to affect biological processes such as transposon silencing through epigenetic effects. Recent studies have found that piRNAs are widely dysregulated in tumors and associated with tumor progression and a poor prognosis. Therefore, this study aimed to investigate the effect of piR-1919609 on the proliferation, apoptosis, and drug resistance of ovarian cancer cells. METHODS: In this study, we used small RNA sequencing to screen and identify differentially expressed piRNAs in primary ovarian cancer, recurrent ovarian cancer, and normal ovaries. A large-scale verification study was performed to verify the expression of piR-1919609 in different types of ovarian tissue, including ovarian cancer tissue and normal ovaries, by RT-PCR and to analyze its association with the clinical prognosis of ovarian cancer. The expression of PIWILs in ovarian cancer was verified by RT-PCR, Western blotting and immunofluorescence. The effects of piR-1919609 on ovarian cancer cell proliferation, apoptosis and drug resistance were studied through in vitro and in vivo models. RESULTS: (1) piR-1919609 was highly expressed in platinum-resistant ovarian cancer tissues (p < 0.05), and this upregulation was significantly associated with a poor prognosis and a shorter recurrence time in ovarian cancer patients (p < 0.05). (2) PIWIL2 was strongly expressed in ovarian cancer tissues (p < 0.05). It was expressed both in the cytoplasm and nucleus of ovarian cancer cells. (3) Overexpression of piR-1919609 promoted ovarian cancer cell proliferation, inhibited apoptosis, and promoted tumor growth in nude mice. (4) Inhibition of piR-1919609 effectively reversed ovarian cancer drug resistance. CONCLUSION: In summary, we showed that piR-1919609 is involved in the regulation of drug resistance in ovarian cancer cells and might be an ideal potential target for reversing platinum resistance in ovarian cancer.


Assuntos
Apoptose , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Neoplasias Ovarianas , RNA Interferente Pequeno , Ensaios Antitumorais Modelo de Xenoenxerto , Feminino , Humanos , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/metabolismo , Animais , Camundongos , Linhagem Celular Tumoral , RNA Interferente Pequeno/genética , Prognóstico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Modelos Animais de Doenças , Platina/uso terapêutico , Platina/farmacologia
5.
J Biomed Sci ; 31(1): 50, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38741159

RESUMO

BACKGROUND: G-quadruplex DNA (G4) is a non-canonical structure forming in guanine-rich regions, which play a vital role in cancer biology and are now being acknowledged in both nuclear and mitochondrial (mt) genome. However, the impact of G4-based targeted therapy on both nuclear and mt genome, affecting mt function and its underlying mechanisms remain largely unexplored. METHODS: The mechanisms of action and therapeutic effects of a G4-binding platinum(II) complex, Pt-ttpy, on mitochondria were conducted through a comprehensive approaches with in vitro and in vivo models, including ICP-MS for platinum measurement, PCR-based genetic analysis, western blotting (WB), confocal microscope for mt morphology study, extracellular flux analyzer, JC1 and Annexin V apoptosis assay, flow cytometry and high content microscope screening with single-cell quantification of both ROS and mt specific ROS, as well as click-chemistry for IF study of mt translation. Decipher Pt-ttpy effects on nuclear-encoded mt related genes expression were undertaken via RNA-seq, Chip-seq and CUT-RUN assays. RESULTS: Pt-ttpy, shows a highest accumulation in the mitochondria of A2780 cancer cells as compared with two other platinum(II) complexes with no/weak G4-binding properties, Pt-tpy and cisplatin. Pt-ttpy induces mtDNA deletion, copy reduction and transcription inhibition, hindering mt protein translation. Functional analysis reveals potent mt dysfunction without reactive oxygen species (ROS) induction. Mechanistic study provided first evidence that most of mt ribosome genes are highly enriched in G4 structures in their promoter regions, notably, Pt-ttpy impairs most nuclear-encoded mt ribosome genes' transcription through dampening the recruiting of transcription initiation and elongation factors of NELFB and TAF1 to their promoter with G4-enriched sequences. In vivo studies show Pt-ttpy's efficient anti-tumor effects, disrupting mt genome function with fewer side effects than cisplatin. CONCLUSION: This study underscores Pt-ttpy as a G4-binding platinum(II) complex, effectively targeting cancer mitochondria through dual action on mt and nuclear G4-enriched genomes without inducing ROS, offering promise for safer and effective platinum-based G4-targeted cancer therapy.


Assuntos
Quadruplex G , Mitocôndrias , Quadruplex G/efeitos dos fármacos , Humanos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Linhagem Celular Tumoral , Genoma Mitocondrial , Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Platina/farmacologia , Animais
6.
Cancer Immunol Immunother ; 73(6): 106, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38634928

RESUMO

BACKGROUND: Immune checkpoint inhibitors have changed previous treatment paradigm of advanced urothelial carcinoma (UC). The ARON-2 study (NCT05290038) aimed to assess the real-world effectiveness of pembrolizumab in patients recurred or progressed after platinum-based chemotherapy. PATIENTS AND METHODS: Medical records of patients with documented metastatic UC treated by pembrolizumab as second-line therapy were retrospectively collected from 88 institutions in 23 countries. Patients were assessed for overall survival (OS), progression-free survival (PFS) and overall response rate (ORR). Cox proportional hazards models were adopted to explore the presence of prognostic factors. RESULTS: In total, 836 patients were included: 544 patients (65%) received pembrolizumab after progression to first-line platinum-based chemotherapy in the metastatic setting (cohort A) and 292 (35%) after recurring within < 12 months since the completion of adjuvant or neoadjuvant chemotherapy (cohort B). The median follow-up time was 15.3 months. The median OS and the ORR were 10.5 months and 31% in the overall study population, 9.1 months and 29% in cohort A and 14.6 months and 37% in cohort B. At multivariate analysis, ECOG-PS ≥ 2, bone metastases, liver metastases and pembrolizumab setting (cohort A vs B) proved to be significantly associated with worst OS and PFS. Stratified by the presence of 0, 1-2 or 3-4 prognostic factors, the median OS was 29.4, 12.5 and 4.1 months (p < 0.001), while the median PFS was 12.2, 6.4 and 2.8 months, respectively (p < 0.001). CONCLUSIONS: Our study confirms that pembrolizumab is effective in the advanced UC real-world context, showing outcome differences between patients recurred or progressed after platinum-based chemotherapy.


Assuntos
Anticorpos Monoclonais Humanizados , Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Humanos , Adjuvantes Imunológicos , Platina , Estudos Retrospectivos
7.
Int J Mol Sci ; 25(8)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38673932

RESUMO

Platinum-containing chemotherapeutic drugs are efficacious in many forms of cancer but are dose-restricted by serious side effects, of which peripheral neuropathy induced by oxidative-nitrosative-stress-mediated chain reactions is most disturbing. Recently, hope has been raised regarding the catalytic antioxidants mangafodipir (MnDPDP) and calmangafodipir [Ca4Mn(DPDP)5; PledOx®], which by mimicking mitochondrial manganese superoxide dismutase (MnSOD) may be expected to overcome oxaliplatin-associated chemotherapy-induced peripheral neuropathy (CIPN). Unfortunately, two recent phase III studies (POLAR A and M trials) applying Ca4Mn(DPDP)5 in colorectal cancer (CRC) patients receiving multiple cycles of FOLFOX6 (5-FU + oxaliplatin) failed to demonstrate efficacy. Instead of an anticipated 50% reduction in the incidence of CIPN in patients co-treated with Ca4Mn(DPDP)5, a statistically significant increase of about 50% was seen. The current article deals with confusing differences between early and positive findings with MnDPDP in comparison to the recent findings with Ca4Mn(DPDP)5. The POLAR failure may also reveal important mechanisms behind oxaliplatin-associated CIPN itself. Thus, exacerbated neurotoxicity in patients receiving Ca4Mn(DPDP)5 may be explained by redox interactions between Pt2+ and Mn2+ and subtle oxidative-nitrosative chain reactions. In peripheral sensory nerves, Pt2+ presumably leads to oxidation of the Mn2+ from Ca4Mn(DPDP)5 as well as from Mn2+ in MnSOD and other endogenous sources. Thereafter, Mn3+ may be oxidized by peroxynitrite (ONOO-) into Mn4+, which drives site-specific nitration of tyrosine (Tyr) 34 in the MnSOD enzyme. Conformational changes of MnSOD then lead to the closure of the superoxide (O2•-) access channel. A similar metal-driven nitration of Tyr74 in cytochrome c will cause an irreversible disruption of electron transport. Altogether, these events may uncover important steps in the mechanism behind Pt2+-associated CIPN. There is little doubt that the efficacy of MnDPDP and its therapeutic improved counterpart Ca4Mn(DPDP)5 mainly depends on their MnSOD-mimetic activity when it comes to their potential use as rescue medicines during, e.g., acute myocardial infarction. However, pharmacokinetic considerations suggest that the efficacy of MnDPDP on Pt2+-associated neurotoxicity depends on another action of this drug. Electron paramagnetic resonance (EPR) studies have demonstrated that Pt2+ outcompetes Mn2+ and endogenous Zn2+ in binding to fodipir (DPDP), hence suggesting that the previously reported protective efficacy of MnDPDP against CIPN is a result of chelation and elimination of Pt2+ by DPDP, which in turn suggests that Mn2+ is unnecessary for efficacy when it comes to oxaliplatin-associated CIPN.


Assuntos
Antineoplásicos , Manganês , Oxaliplatina , Doenças do Sistema Nervoso Periférico , Platina , Humanos , Antineoplásicos/efeitos adversos , Ácido Edético/análogos & derivados , Manganês/efeitos adversos , Estresse Nitrosativo/efeitos dos fármacos , Oxaliplatina/efeitos adversos , Oxaliplatina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/metabolismo , Platina/efeitos adversos , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/farmacologia , Fosfato de Piridoxal/metabolismo , Superóxido Dismutase/metabolismo , Ensaios Clínicos Fase III como Assunto
8.
Sci Rep ; 14(1): 8882, 2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632263

RESUMO

Wearable long-term monitoring applications are becoming more and more popular in both the consumer and the medical market. In wearable ECG monitoring, the data quality depends on the properties of the electrodes and on how they interface with the skin. Dry electrodes do not require any action from the user. They usually do not irritate the skin, and they provide sufficiently high-quality data for ECG monitoring purposes during low-intensity user activity. We investigated prospective motion artifact-resistant dry electrode materials for wearable ECG monitoring. The tested materials were (1) porous: conductive polymer, conductive silver fabric; and (2) solid: stainless steel, silver, and platinum. ECG was acquired from test subjects in a 10-min continuous settling test and in a 48-h intermittent long-term test. In the settling test, the electrodes were stationary, whereas both stationary and controlled motion artifact tests were included in the long-term test. The signal-to-noise ratio (SNR) was used as the figure of merit to quantify the results. Skin-electrode interface impedance was measured to quantify its effect on the ECG, as well as to leverage the dry electrode ECG amplifier design. The SNR of all electrode types increased during the settling test. In the long-term test, the SNR was generally elevated further. The introduction of electrode movement reduced the SNR markedly. Solid electrodes had a higher SNR and lower skin-electrode impedance than porous electrodes. In the stationary testing, stainless steel showed the highest SNR, followed by platinum, silver, conductive polymer, and conductive fabric. In the movement testing, the order was platinum, stainless steel, silver, conductive polymer, and conductive fabric.


Assuntos
Artefatos , Aço Inoxidável , Humanos , Platina , Prata , Estudos Prospectivos , Eletrocardiografia/métodos , Impedância Elétrica , Eletrodos , Polímeros
9.
Artigo em Chinês | MEDLINE | ID: mdl-38599639

RESUMO

Objective: To evaluate the efficacy and safety of pembrolizumab plus nab-paclitaxel and platinum as first-line treatment in patients with recurrent or metastatic head and neck squamous-cell carcinoma (R/M HNSCC). Methods: This was a prospective, single-arm, open label, phase 2 clinical study enrolling patients at the Cancer Hospital of the Chinese Academy of Medical Sciences with R/M HNSCC treated with pembrolizumab plus nab-paclitaxel and cisplatin or carboplatin. After six cycles of treatment, patients received pembrolizumab as maintenance therapy until disease progression or intolerable toxicity or completion of 35 cycles of treatment. The primary endpoint was objective response rate, and secondary endpoints included overall survival, progression-free survival, and safety profile. Efficacy was evaluated according to the response evaluation criteria in solid tumors 1.1, survival analysis was performed using the Kaplan-Meier method, and adverse events were assessed using the America National Cancer Institute Common Terminology Criteria for Adverse Events 5.0. Results: A total of 30 patients with R/M HNSCC were enrolled from 23 April 2021 to 22 March 2023, including 28 males and 2 females, with a median age of 67 years. The median follow-up time was 14.5 months, the objective response rate was 70.0%, the disease control rate was 96.7%, and the median progression-free survival and overall survival of all patients were 11.6 months and 18.8 months, respectively. Median duration of response was up to 17.3 months. Grade≥3 treatment-related adverse events were leukopenia (26.7%), neutropenia (26.7%), peripheral neurotoxicity (3.3%), rash (3.3%), hyperalgesia (3.3%), and immune-related pneumonitis (3.3%). The most common immune-related adverse event was hypothyroidism (40.0%). Conclusion: Pembrolizumab combined with nab-paclitaxel and platinum shows encouraging antitumor activity accompanied with a manageable safety profile in untreated R/M HNSCC patients in China.


Assuntos
Albuminas , Anticorpos Monoclonais Humanizados , Neoplasias de Cabeça e Pescoço , Platina , Masculino , Feminino , Humanos , Idoso , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Estudos Prospectivos , Paclitaxel/uso terapêutico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
10.
Biosensors (Basel) ; 14(4)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38667165

RESUMO

The exploration into nanomaterial-based nonenzymatic biosensors with superb performance in terms of good sensitivity and anti-interference ability in disease marker monitoring has always attained undoubted priority in sensing systems. In this work, we report the design and synthesis of a highly active nanocatalyst, i.e., palladium and platinum nanoparticles (Pt&Pd-NPs) decorated ultrathin nanoporous gold (NPG) film, which is modified on a homemade graphene paper (GP) to develop a high-performance freestanding and flexible nanohybrid electrode. Owing to the structural characteristics the robust GP electrode substrate, and high electrochemically catalytic activities and durability of the permeable NPG support and ultrafine and high-density Pt&Pd-NPs on it, the resultant Pt&Pd-NPs-NPG/GP electrode exhibits excellent sensing performance of low detection limitation, high sensitivity and anti-interference capability, good reproducibility and long-term stability for the detection of small molecular biomarkers hydrogen peroxide (H2O2) and glucose (Glu), and has been applied to the monitoring of H2O2 in different types of live cells and Glu in body fluids such as urine and fingertip blood, which is of great significance for the clinical diagnosis and prognosis in point-of-care testing.


Assuntos
Biomarcadores , Técnicas Biossensoriais , Técnicas Eletroquímicas , Ouro , Grafite , Nanopartículas Metálicas , Paládio , Platina , Grafite/química , Ouro/química , Platina/química , Paládio/química , Nanopartículas Metálicas/química , Biomarcadores/urina , Humanos , Peróxido de Hidrogênio , Ligas/química , Glucose/análise , Eletrodos , Papel
11.
Sensors (Basel) ; 24(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38676026

RESUMO

This work presents a novel multielectrode array (MEA) to quantitatively assess the dose enhancement factor (DEF) produced in a medium by embedded nanoparticles. The MEA has 16 nanocrystalline diamond electrodes (in a cell-culture well), and a single-crystal diamond divided into four quadrants for X-ray dosimetry. DEF was assessed in water solutions with up to a 1000 µg/mL concentration of silver, platinum, and gold nanoparticles. The X-ray detectors showed a linear response to radiation dose (r2 ≥ 0.9999). Overall, platinum and gold nanoparticles produced a dose enhancement in the medium (maximum of 1.9 and 3.1, respectively), while silver nanoparticles produced a shielding effect (maximum of 37%), lowering the dose in the medium. This work shows that the novel MEA can be a useful tool in the quantitative assessment of radiation dose enhancement due to nanoparticles. Together with its suitability for cells' exocytosis studies, it proves to be a highly versatile device for several applications.


Assuntos
Diamante , Eletrodos , Ouro , Nanopartículas Metálicas , Diamante/química , Nanopartículas Metálicas/química , Ouro/química , Prata/química , Platina/química , Doses de Radiação , Humanos , Raios X , Nanopartículas/química
12.
ACS Appl Mater Interfaces ; 16(17): 22704-22714, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38640487

RESUMO

Balancing the accuracy and simplicity of aptasensors is a challenge in their construction. This study addresses this issue by leveraging the remarkable loading capacity and peroxidase-like catalytic activity of PtPdCu trimetallic nanoparticles, which reduces the reliance on precious metals. A dual-signal readout aptasensor for enrofloxacin (ENR) detection is designed, incorporating DNA dynamic network cascade reactions to further amplify the output signal. Exploiting the strong loading capacity of PtPdCu nanoparticles, they are self-assembled with thionine (Thi) to form a signal label capable of generating signals in two independent modes. The label exhibits excellent enzyme-like catalytic activity and enhances electron transfer capabilities. Differential pulse voltammetry (DPV) and square-wave voltammetry (SWV) are employed to independently read signals from the oxidation-reduction reaction of Thi and the catalytic oxidation of hydroquinone (HQ) to benzoquinone (BQ) by H2O2. The introduced DNA dynamic network cascade reaction modularizes sample processing and electrode surface signal generation, avoiding electrode contamination and efficiently increasing the output of the catalyzed hairpin assembly (CHA) cycle. Under optimized conditions, the developed aptasensor demonstrates detection limits of 0.112 (DPV mode) and 0.0203 pg/mL (SWV mode). Additionally, the sensor successfully detected enrofloxacin in real samples, expanding avenues for designing dual-mode signal amplification strategies.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Cobre , Enrofloxacina , Nanopartículas Metálicas , Platina , Enrofloxacina/análise , Aptâmeros de Nucleotídeos/química , Nanopartículas Metálicas/química , Técnicas Biossensoriais/métodos , Cobre/química , Platina/química , Rutênio/química , Técnicas Eletroquímicas/métodos , Limite de Detecção , Oxirredução , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/análise , Catálise , Antibacterianos/análise , Antibacterianos/química
13.
Lab Chip ; 24(10): 2712-2720, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38655620

RESUMO

A colorimetric biosensor was elaboratively designed for fast, sensitive and multiplex bacterial detection on a single microfluidic chip using immune magnetic nanobeads for specific bacterial separation, immune gold@platinum palladium nanoparticles for specific bacterial labeling, a finger-actuated mixer for efficient immunoreaction and two coaxial rotatable magnetic fields for magnetic nanobead capture (outer one) and magnet-actuated valve control (inner one). First, preloaded bacteria, nanobeads and nanozymes were mixed through a finger actuator to form nanobead-bacteria-nanozyme conjugates, which were captured by the outer magnetic field. After the inner magnetic field was rotated to successively wash the conjugates and push the H2O2-TMB substrate for resuspending these conjugates, colorless TMB was catalyzed into blue TMBox products, followed by color analysis using ImageJ software for bacterial determination. This simple biosensor enabled multiplex Salmonella detection as low as 9 CFU per sample in 45 min.


Assuntos
Técnicas Biossensoriais , Dispositivos Lab-On-A-Chip , Salmonella , Técnicas Biossensoriais/instrumentação , Salmonella/isolamento & purificação , Colorimetria/instrumentação , Ouro/química , Técnicas Analíticas Microfluídicas/instrumentação , Paládio/química , Nanopartículas Metálicas/química , Platina/química
14.
Int J Mol Sci ; 25(7)2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38612862

RESUMO

The nucleophilic addition of 3-(4-cyanopyridin-2-yl)-1,1-dimethylurea (1) to cis-[Pt(CNXyl)2Cl2] (2) gave a new cyclometallated compound 3. It was characterized by NMR spectroscopy (1H, 13C, 195Pt) and high-resolution mass spectrometry, as well as crystallized to obtain two crystalline forms (3 and 3·2MeCN), whose structures were determined by X-ray diffraction. In the crystalline structure of 3, two conformers (3A and 3B) were identified, while the structure 3·2MeCN had only one conformer 3A. The conformers differed by orientation of the N,N-dimethylcarbamoyl moiety relative to the metallacycle plane. In both crystals 3 and 3·2MeCN, the molecules of the Pt(II) complex are associated into supramolecular dimers, either {3A}2 or {3B}2, via stacking interactions between the planes of two metal centers, which are additionally supported by hydrogen bonding. The theoretical consideration, utilizing a number of computational approaches, demonstrates that the C···dz2(Pt) interaction makes a significant contribution in the total stacking forces in the geometrically optimized dimer [3A]2 and reveals the dz2(Pt)→π*(PyCN) charge transfer (CT). The presence of such CT process allowed for marking the C···Pt contact as a new example of a rare studied phenomenon, namely, tetrel bonding, in which the metal site acts as a Lewis base (an acceptor of noncovalent interaction).


Assuntos
Bases de Lewis , Platina , Ligantes , Ligação de Hidrogênio , Polímeros , Ureia
15.
An Acad Bras Cienc ; 96(1): e20230067, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38656055

RESUMO

Platinum nanoparticles supported by carbon nanotubes were obtained by a simple chemical route and used for preparation of electrochemical sensor towards caffeine determination. Carbon nanotubes were used before and after an acid treatment, yielding two different materials. Morphological and structural characterization of these materials showed platinum nanoparticles (size around 12 nm) distributed randomly along carbon nanotubes. Modified electrodes were directly prepared through a dispersion of these materials. Voltammetric studies in the presence of caffeine revealed an electrocatalytic effect of platinum oxides, electrochemically produced from the chemical oxidation of the platinum nanoparticles. This behavior was explored in the development a selective method for caffeine determination based on platinum oxide reduction at a lower potential value (+0.45 V vs. Ag/AgCl). Using the best set of experimental conditions, it was shown a linear relationship for the caffeine concentration ranging from 5.0 to 25 µmol L-1 with a sensitivity of 449 nA L µmol-1. Limits of detection and quantification of 0.54 and 1.80 µmol L-1 were calculated, respectively. Recovery values for real samples of caffeine pharmaceutical formulations between 98.6% and 101.0% (n = 3) were obtained using the proposed procedure. Statistical calculations showed good concordance (95% confidence level) between the added and recovery values.


Assuntos
Cafeína , Técnicas Eletroquímicas , Nanopartículas Metálicas , Nanotubos de Carbono , Platina , Nanotubos de Carbono/química , Cafeína/análise , Cafeína/química , Platina/química , Nanopartículas Metálicas/química , Técnicas Eletroquímicas/métodos , Eletrodos , Limite de Detecção , Reprodutibilidade dos Testes , Oxirredução
16.
Medicine (Baltimore) ; 103(16): e37836, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38640325

RESUMO

BACKGROUND: Durvalumab plus etoposide-platinum (DEP) showed sustained overall survival improvements in patients with extensive-stage small-cell lung cancer (ES-SCLC) compared to etoposide-platinum (EP), but adding tremelimumab to DEP (DTEP) did not significantly improve outcomes. A third-party payer perspective is taken here to evaluate the cost-effectiveness of DTEP, DEP, and EP for ES-SCLC. METHODS: The cost-effectiveness was evaluated by partitioning survival models into 3 mutually exclusive health states. In this model, clinical characteristics and outcomes were obtained from the CASPIAN. Model robustness was evaluated through 1-way deterministic and probabilistic sensitivity analyses. Outcome measurements included costs, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratio, life-years, incremental net health benefit, and incremental net monetary benefit. The analysis was conducted with a 10-year lifetime horizon in a United States setting. RESULTS: Compared with EP, DEP, and DTEP were associated with an increment of 0.480 and 0.313 life-years, and an increment of 0.247 and 0.165 QALYs, as well as a $139,788 and $170,331 increase in cost per patient. The corresponding ICERs were $565,807/QALY and $1033,456/QALY, respectively. The incremental net health benefit and incremental net monetary benefit of DEP or DTEP were -0.685 QALYs and -$102,729, or -0.971 QALYs and -$145,608 at a willingness to pay threshold of $150,000/QALY, respectively. Compared with DTEP, DEP was dominated. DTEP and DEP were 100% unlikely to be cost-effective if the willingness to pay threshold was $150,000/QALY. DEP was cost-effective compared to EP when durvalumab was priced below $0.994/mg. Compared with EP, DEP, and DTEP were unlikely to be considered cost-effective across all subgroups. CONCLUSION: DEP and DTEP were not cost-effective options in the first-line treatment for ES-SCLC compared with EP, from the third-party payer perspective in the United States. Compared with DTEP, DEP was dominated.


Assuntos
Anticorpos Monoclonais Humanizados , Anticorpos Monoclonais , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Estados Unidos , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Etoposídeo/uso terapêutico , Platina/uso terapêutico , Análise de Custo-Efetividade , Análise Custo-Benefício , Anos de Vida Ajustados por Qualidade de Vida , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
17.
ACS Sens ; 9(4): 2101-2109, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38574240

RESUMO

Single-atom catalysts (SACs) hold great promise in highly sensitive and selective gas sensors due to their ultrahigh atomic efficiency and excellent catalytic activity. However, due to the extremely high surface energy of SACs, it is still a huge challenge to synthesize a stable single-atom metal on sensitive materials. Here, we report an atomic layer deposition (ALD) strategy for the elaborate synthesis of single-atom Pt on oxygen vacancy-rich Fe2O3 nanosheets (Pt-Fe2O3-Vo), which displayed ultrafast and sensitive detection to H2, achieving the stability of Pt single atoms. Gas-sensing investigation showed that the Pt-Fe2O3-Vo materials enabled a significantly enhanced response of 26.5-50 ppm of H2, which was 17-fold higher than that of pure Fe2O3, as well as ultrafast response time (2 s), extremely low detection limit (86 ppb), and improved stability. The experimental and density functional theory (DFT) studies revealed that the abundant oxygen vacancy sites of Fe2O3 contributed to stabilizing the Pt atoms via electron transfer. In addition, the stabilized Pt atoms also greatly promote the electron transfer of H2 molecules to Fe2O3, thereby achieving an excellent H2 sensing performance. This work provides a potential strategy for the development of highly selective and stable chemical sensors.


Assuntos
Compostos Férricos , Hidrogênio , Nanoestruturas , Oxigênio , Platina , Platina/química , Oxigênio/química , Hidrogênio/química , Compostos Férricos/química , Nanoestruturas/química , Teoria da Densidade Funcional , Catálise , Limite de Detecção
18.
ACS Sens ; 9(4): 2183-2193, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38588327

RESUMO

Sensitive and selective acetone detection is of great significance in the fields of environmental protection, industrial production, and individual health monitoring from exhaled breath. To achieve this goal, bimetallic Au@Pt core-shell nanospheres (BNSs) functionalized-electrospun ZnFe2O4 nanofibers (ZFO NFs) are prepared in this work. Compared to pure NFs-650 analogue, the ZFO NFs/BNSs-2 sensor exhibits a stronger mean response (3.32 vs 1.84), quicker response/recovery speeds (33 s/28 s vs 54 s/42 s), and lower operating temperature (188 vs 273 °C) toward 0.5 ppm acetone. Note that an experimental detection limit of 30 ppb is achieved, which ranks among the best cases reported thus far. Besides the demonstrated excellent repeatability, humidity-enhanced response, and long-term stability, the selectivity toward acetone is remarkably improved after BNSs functionalization. Through material characterizations and DFT calculations, all these improvements could be attributed to the boosted oxygen vacancies and abundant Schottky junctions between ZFO NFs and BNSs, and the synergistic catalytic effect of BNSs. This work offers an alternative strategy to realize selective subppm acetone under high-humidity conditions catering for the future requirements of noninvasive breath diabetes diagnosis in the field of individual healthcare.


Assuntos
Acetona , Testes Respiratórios , Ouro , Nanofibras , Nanosferas , Platina , Acetona/análise , Acetona/química , Nanofibras/química , Ouro/química , Testes Respiratórios/métodos , Nanosferas/química , Platina/química , Humanos , Limite de Detecção , Oxigênio/química , Técnicas Eletroquímicas/métodos
19.
Zhonghua Jie He He Hu Xi Za Zhi ; 47(4): 325-331, 2024 Apr 12.
Artigo em Chinês | MEDLINE | ID: mdl-38599807

RESUMO

Objective: To analyze the clinical characteristics and prognosis of 17 patients with pathologically confirmed SMARCA4-deficient chest tumors. Methods: Seventeen patients with SMARCA4-deficient thoracic tumors diagnosed by pathology in the Affiliated Hospital of Jining Medical University from September 2021 to January 2023 were collected through Results Query System of Pathology Department, and the patients' general conditions, clinical symptoms, tumor markers, imaging features, treatment and regression were retrospectively analyzed, and literature review was performed. Results: A total of 17 patients were included in this study. Their clinical characteristics were characterized as follows: male/female=16/1, age 42-74 years, mean (64.0±5.7)years. Only 1 female had no clear smoking history, and 16 males had a smoking history, of whom 1 had 5 smoking pack-years, and the remaining 15 case had a smoking history of 20-100 smoking pack-years, with a mean of (68.5±44.5) smoking pack-years. Clinical symptoms were mainly cough and sputum, followed by chest tightness, hemoptysis and chest pain. Tumor markers CYFRA19-9 was elevated in 9 cases (3.79-16.61 ng/ml), CEA was elevated in 8 cases (5.37-295.93 ng/ml), and NSE was elevated in 6 cases (17.18-70.37 ng/ml). Imaging manifestations were intrapulmonary or mediastinal mass shadows, and the tumor involved the mediastinum in 9 cases, the upper lobe of the right lung in 6 cases, the upper lobe of the left lung in 5 cases, the lower lobe of the right lung in 3 cases, the lower lobe of the left lung in 3 cases; cervical or supraclavicular lymph node metastasis in 8 cases, pleural metastasis in 4 cases, hepatic metastasis in 3 cases, cerebral metastasis in 3 cases, bone metastasis in 2 cases, and subcutaneous metastasis in 1 case. Combining immuno-histochemistry and pathology, there were 6 cases of SMARCA4-deficient NSCLC and 11 cases of SMARCA4-deficient undifferentiated tumor. Eight patients were treated with platinum-contained chemotherapy agents, four of which were combined with immune checkpoint inhibitors, and one was treated with enzatinib; only one of the 9 patients achieved partial remission after treatment, and the remaining eight had progression of the tumors on chest CT after treatment. Five patients abandoned the treatment, and died in 6-month of follow-up. Three patients underwent surgery for resection, and there was no significant progression in the three patients in the 6 months of follow-up. Conclusions: Clinically, middle-aged and elderly men with a history of heavy smoking should be given high priority, especially in patients whose imaging mostly showed intrapulmonary, especially in upper lobes, and/or mediastinal masses, rapid lesion progression, and early distant metastasis, and who should be alerted to the possibility of SMARCA4-deficient thoracic tumors. Late clinical stage is a high risk factor for poor overall patient survival, and platinum-containing chemotherapy agents combined with immune checkpoint inhibitor therapy may be effective, and early surgery may improve patient prognosis.


Assuntos
Neoplasias Torácicas , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Biomarcadores Tumorais , DNA Helicases , Neoplasias Pulmonares/patologia , Proteínas Nucleares , Platina , Prognóstico , Estudos Retrospectivos , Neoplasias Torácicas/patologia , Fatores de Transcrição
20.
Front Immunol ; 15: 1354613, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38617840

RESUMO

Metastatic colon cancer remains an incurable disease, and it is difficult for existing treatments to achieve the desired clinical outcome, especially for colon cancer patients who have received first-line treatment. Although immune checkpoint inhibitors (ICIs) have demonstrated durable clinical efficacy in a variety of solid tumors, their response requires an inflammatory tumor microenvironment. However, microsatellite-stable (MSS) colon cancer, which accounts for the majority of colorectal cancers, is a cold tumor that does not respond well to ICIs. Combination regimens open the door to the utility of ICIs in cold tumors. Although combination therapies have shown their advantage even for MSS colon cancer, it remains unclear whether combination therapies show their advantage in patients with pretreated metastatic colon cancer. We report a patient who has achieved complete remission and good tolerance with sintilimab plus bevacizumab and platinum-based chemotherapy after postoperative recurrence. The patient had KRAS mutation and MSS-type colon cancer, and his PD-1+CD8+ and CD3-CD19-CD14+CD16-HLA-DR were both positive. He has achieved a progression-free survival of 43 months and is still being followed up at our center. The above results suggest that this therapeutic regimen is a promising treatment modality for the management of pretreated, MSS-type and KRAS-mutated metastatic colorectal cancer although its application to the general public still needs to be validated in clinical trials.


Assuntos
Anticorpos Monoclonais Humanizados , Neoplasias do Colo , Proteínas Proto-Oncogênicas p21(ras) , Masculino , Humanos , Bevacizumab/uso terapêutico , Proteínas Proto-Oncogênicas p21(ras)/genética , Resposta Patológica Completa , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Platina , Repetições de Microssatélites , Microambiente Tumoral
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