Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Adv Mater ; : e2404330, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38723269

RESUMO

The pursuit of constructing humanoid robots to replicate the anatomical structures and capabilities of human beings has been a long-standing significant undertaking and especially garnered tremendous attention in recent years. However, despite the progress made over recent decades, humanoid robots have predominantly been confined to those rigid metallic structures, which however starkly contrast with the inherent flexibility observed in biological systems. To better innovate this area, the present article systematically explores the value and potential of liquid metals and their derivatives in facilitating a crucial transition towards soft humanoid robots. Through a comprehensive interpretation of bionics, we present an overview of liquid metals' multifaceted roles as essential components in constructing advanced humanoid robots - functioning as soft actuators, sensors, power sources, logical devices, circuit systems, and even transformable skeletal structures. We conceived that the integration of these components with flexible structures, facilitated by the unique properties of liquid metals, can create unexpected versatile functionalities and behaviors to better fulfill human needs. Finally, we envision a revolution in humanoid robots, transitioning from metallic frameworks to hybrid soft-rigid structures resembling that of biological tissues. This article is expected to provide fundamental guidance for the coming research, thereby advancing the area. This article is protected by copyright. All rights reserved.

4.
Angew Chem Int Ed Engl ; 62(6): e202216365, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36515186

RESUMO

Chemical synthesis of insulin superfamily proteins (ISPs) has recently been widely studied to develop next-generation drugs. Separate synthesis of multiple peptide fragments and tedious chain-to-chain folding are usually encountered in these studies, limiting accessibility to ISP derivatives. Here we report the finding that insulin superfamily proteins (e.g. H2 relaxin, insulin itself, and H3 relaxin) incorporating a pre-made diaminodiacid bridge at A-B chain terminal disulfide can be easily and rapidly synthesized by a single-shot automated solid-phase synthesis and expedient one-step folding. Our new H2 relaxin analogues exhibit almost identical structures and activities when compared to their natural counterparts. This new synthetic strategy will expediate production of new ISP analogues for pharmaceutical studies.


Assuntos
Relaxina , Relaxina/química , Relaxina/metabolismo , Dissulfetos/química , Técnicas de Síntese em Fase Sólida , Proteínas/química , Insulina/química , Receptores Acoplados a Proteínas G/metabolismo
5.
Front Nutr ; 9: 966276, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35983489

RESUMO

Ellagic acid (EA) is a dietary polyphenol that widely exists in grapes, strawberries, and walnuts. It usually exerts multiple biological activities together with its in vivo metabolites called urolithins. EA and urolithins had been proposed as natural agents for applying on the early intervention of Alzheimer's disease (AD). However, the neuroprotective effects of those small molecules have not been confirmed, and the action mechanism is not clear. Deposition of beta-amyloid (Aß) protein is well documented as being involved in the initiation and pathological process of AD. In the present study, we investigated the attenuating effects of EA and several urolithins on Aß25-35-induced neuronal injury and its underlying molecular mechanism by constructing the in vitro AD cell model of PC12 cells and primary neurons. The results revealed that EA and urolithins especially the UM5 and UM6 exerted promising neuroprotective effects in improving the Aß25-35-induced cell damage and lactate dehydrogenase (LDH) leakage, reducing reactive oxygen species (ROS) production, inhibiting neuronal apoptosis, and promoting neurite outgrowth. These results provide new insights into the development of UM5 and UM6 as anti-AD candidates. A network pharmacology analysis combining molecular docking strategy was further adopted to predict the signaling pathway involved in the anti-AD action of EA and urolithins, and the activation of PI3K-Akt, as well as the inhibition of MAPK was found to be involved.

7.
Nanomaterials (Basel) ; 12(11)2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35683791

RESUMO

Photothermal therapy (PTT) has become an important therapeutic strategy in the treatment of cancer. However, exploring novel photothermal nanomaterials with satisfactory biocompatibility, high photothermal conversion efficiency, and efficient theranostic outcomes, remains a major challenge for satisfying clinical application. In this study, poly-ethylene glycol modified rhenium disulfide (PEG-ReS2) nanosheets are constructed by a simple-liquid phase exfoliation method. The PEG-ReS2 nanosheets were demonstrated to have good solubility, good biocompatibility, low toxicity, and strong capability of accumulating near-infrared (NIR) photons. Under 808 nm laser irradiation, the PEG-ReS2 nanosheets were found to have an excellent photothermal conversion efficiency (PTCE) of 42%. Moreover, the PEG-ReS2 nanosheets were demonstrated to be ideal photothermal transduction agents (PTAs), which promoted rapid cancer cell death in vitro and efficiently ablated tumors in vivo. Interestingly, the potential utility of up-regulation or down-regulation of miRNAs was proposed to evaluate the therapeutic outcomes of PEG-ReS2 nanosheets. The expression levels of a set of miRNAs in tumor-bearing mice were restored to normal levels after PTT therapy with PEG-ReS2 nanosheets. Both down-regulation miRNAs (miR-125a-5p, miR-34a-5p, miR-132-3p, and miR-148b-3p) and up-regulation miRNAs (miR-133a-3p, miR-200c-5p, miR-9-3p, and miR-150-3p) were suggested to be important clinical biomarkers for evaluating therapeutic outcomes of breast cancer-related PTT. This work highlights the great significance of PEG-ReS2 nanosheets as therapeutic nanoagents for cancer therapy.

8.
Cell Discov ; 8(1): 47, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35595746

RESUMO

The endogenous cyclic tetradecapeptide SST14 was reported to stimulate all five somatostatin receptors (SSTR1-5) for hormone release, neurotransmission, cell growth arrest and cancer suppression. Two SST14-derived short cyclic SST analogues (lanreotide or octreotide) with improved stability and longer lifetime were developed as drugs to preferentially activate SSTR2 and treat acromegalia and neuroendocrine tumors. Here, cryo-EM structures of the human SSTR2-Gi complex bound with SST14, octreotide or lanreotide were determined at resolutions of 2.85 Å, 2.97 Å, and 2.87 Å, respectively. Structural and functional analysis revealed that interactions between ß-turn residues in SST analogues and transmembrane SSTR2 residues in the ligand-binding pocket are crucial for receptor binding and functional stimulation of the two SST14-derived cyclic octapeptides. Additionally, Q1022.63, N2766.55, and F2947.35 could be responsible for the selectivity of lanreotide or octreotide for SSTR2 over SSTR1 or SSTR4. These results provide valuable insights into further rational development of SST analogue drugs targeting SSTR2.

11.
Cancer Biother Radiopharm ; 37(2): 141-146, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32822222

RESUMO

Background: This study investigated the efficacy and complications of microwave ablation in combination with chemotherapy in treating peripheral IIIB-IV non-small cell lung cancer (NSCLC). Materials and Methods: A total of 100 patients with peripheral IIIB-IV NSCLC were randomly divided into two groups: combination group (n = 52) and chemotherapy group (n = 48). Patients in the combination group were treated with microwave ablation, radiotherapy, and chemotherapy, whereas the patients in the chemotherapy group were treated with pemetrexed disodium or gemcitabine hydrochloride, cisplatin chemotherapy, and conventional radiotherapy. Results: The effectiveness and disease control rates were significantly higher in the combination group than in the chemotherapy group (p < 0.05). The second- and third-year survival rates were significantly higher in the combination group than in the chemotherapy group (p < 0.05). However, patients in the combination group had no serious complications, and there were no intraoperative and perioperative deaths. Conclusions: Microwave ablation is safe and effective. Combination chemotherapy is superior to chemotherapy in treating peripheral IIIB-IV NSCLC in terms of effectiveness rate, disease control rate, and extended patient survival time.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Cisplatino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/cirurgia , Micro-Ondas/uso terapêutico , Estadiamento de Neoplasias , Pemetrexede
13.
Cell Res ; 31(4): 383-394, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33603117

RESUMO

The human calcium-sensing receptor (CaSR) is a class C G protein-coupled receptor (GPCR) responsible for maintaining Ca2+ homeostasis in the blood. The general consensus is that extracellular Ca2+ is the principal agonist of CaSR. Aliphatic and aromatic L-amino acids, such as L-Phe and L-Trp, increase the sensitivity of CaSR towards Ca2+ and are considered allosteric activators. Crystal structures of the extracellular domain (ECD) of CaSR dimer have demonstrated Ca2+ and L-Trp binding sites and conformational changes of the ECD upon Ca2+/L-Trp binding. However, it remains to be understood at the structural level how Ca2+/L-Trp binding to the ECD leads to conformational changes in transmembrane domains (TMDs) and consequent CaSR activation. Here, we determined the structures of full-length human CaSR in the inactive state, Ca2+- or L-Trp-bound states, and Ca2+/L-Trp-bound active state using single-particle cryo-electron microscopy. Structural studies demonstrate that L-Trp binding induces the closure of the Venus flytrap (VFT) domain of CaSR, bringing the receptor into an intermediate active state. Ca2+ binding relays the conformational changes from the VFT domains to the TMDs, consequently inducing close contact between the two TMDs of dimeric CaSR, activating the receptor. Importantly, our structural and functional studies reveal that Ca2+ ions and L-Trp activate CaSR cooperatively. Amino acids are not able to activate CaSR alone, but can promote the receptor activation in the presence of Ca2+. Our data provide complementary insights into the activation of class C GPCRs and may aid in the development of novel drugs targeting CaSR.


Assuntos
Cálcio/metabolismo , Receptores de Detecção de Cálcio/metabolismo , Triptofano/metabolismo , Sítios de Ligação , Cálcio/química , Microscopia Crioeletrônica , Humanos , Íons/química , Simulação de Dinâmica Molecular , Ligação Proteica , Receptores de Detecção de Cálcio/química , Receptores de Detecção de Cálcio/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Triptofano/química
15.
Materials (Basel) ; 13(13)2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32640688

RESUMO

Graphene oxide(GO)/polylactic acid (PLA) nanocomposite, prepared using a solvent-free melt mixing processing, is investigated as a potential oxygen barrier packaging film in this work. In order to disperse GO homogeneously in PLA matrix, hydrophobic silane coupling agent, i.e., γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH560), is used to modify the graphene oxide sheets. The modified GO is able to be well bonded to the PLA due to the formation of covalent bonds between the epoxy groups of KH560 and the carboxyl and hydroxyl terminal groups of PLA. Furthermore, the thermal stability of GO is enhanced due to the long alkyl side chain of KH560, which could also increase the crystallinity of PLA. As a result, the crystallinity of PLA is significantly improved because of the linear KH560 chains, which can act as nucleating agents to improve the crystallization. The KH560-GO helps to reduce the O2 permeability of KH560-GO/PLA composite films via a dual-action mechanism: (1) providing physical barrier due to their native barrier properties, and (2) by resulting in higher degree of crystallinity. The as-prepared KH560-GO0.75/PLA is able to exhibit ca. 33% and ca. 13% decrease in the PO2 than the neat PLA and GO0.75/PLA film, respectively. Finally, the mechanical properties and impact fractured surfaces indicate that the increase in the tensile strength and elongation at break value of KH560-GO/PLA are due to the strong interfacial adhesion and the strong bonding between the epoxy group of KH560-GO and hydroxyl and carboxyl acid terminal groups of PLA matrix.

16.
Sensors (Basel) ; 20(11)2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32545230

RESUMO

This study theoretically proposed a novel surface plasmon resonance biosensor by incorporating emerging two dimensional material blue phosphorus and graphene layers with plasmonic gold film. The excellent performances employed for biosensing can be realized by accurately tuning the thickness of gold film and the number of blue phosphorus interlayer. Our proposed plasmonic biosensor architecture designed by phase modulation is much superior to angular modulation, providing 4 orders of magnitude sensitivity enhancement. In addition, the optimized stacked configuration is 42 nm Au film/2-layer blue phosphorus /4-layer graphene, which can produce the sharpest differential phase of 176.7661 degrees and darkest minimum reflectivity as low as 5.3787 × 10-6. For a tiny variation in local refractive index of 0.0012 RIU (RIU, refractive index unit) due to the binding interactions of aromatic biomolecules, our proposed biosensor can provide an ultrahigh detection sensitivity up to 1.4731 × 105 °/RIU, highly promising for performing ultrasensitive biosensing application.


Assuntos
Técnicas Biossensoriais , Grafite , Ressonância de Plasmônio de Superfície , Ouro , Fósforo
17.
Clin Respir J ; 14(9): 864-870, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32445215

RESUMO

OBJECTIVE: Solving the limitations of single chemotherapy in the treatment of non-small cell lung cancer (NSCLC). METHODS: About 100 patients with NSCLC treated in First Hospital of Jiaxing, Zhejiang from June 2016 to June 2018 were selected and randomly divided into MPC group and MGC group, with 50 cases in each group. The patients in MPC group were treated with microwave ablation (MWA) combined with PC while patients in MGC group were given MWA combined with gemcitabine plus cisplatin (GC). The therapeutic effects of the two groups as well as the complications and adverse reactions (ADRs) were observed and recorded. RESULTS: There was no significant difference in disease response rate (MPC group 33.3% vs MGC group 32.0%), disease control rate (MPC group 86.4% vs MGC group 78.0%) and overall survival (1-, 2- and 3-year survival, MPC group 65%, 59%, 32.7% vs MGC group 58%, 46%, 30%) between the two groups. In addition, the ADR myelosuppression was slighter in MPC group. There were 12 cases (23%) developed myelosuppression in the MPC group and 20 cases (42%) in MGC group, with a significant difference between the two groups (P < 0.05). The treatment was interrupted for 0 case (0%) in MPC group because of myelosuppression while 4 cases (8.3%) in MGC group. CONCLUSION: The two therapeutic regimens have similar efficacy in treatment of advanced NSCLC, but MPC causes slighter myelosuppression and can be the first-line therapy for advanced NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Cisplatino/uso terapêutico , Desoxicitidina/análogos & derivados , Glutamatos/uso terapêutico , Guanina/uso terapêutico , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Micro-Ondas , Estadiamento de Neoplasias , Pemetrexede/uso terapêutico , Resultado do Tratamento , Gencitabina
18.
J Phys Chem A ; 124(21): 4235-4240, 2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32364735

RESUMO

In the prodrug research field, information obtained from traditional end point biochemical assays in drug effect studies could provide neither the dynamic processes nor heterogeneous responses of individual cells. In situ imaging microscopy techniques, especially fluorescence lifetime imaging microscopy (FLIM), could fulfill these requirements. In this work, we used FLIM techniques to observe the entry and release of doxorubicin (Dox)-Cu complexes in live KYSE150 cells. The Dox-Cu complex has weaker fluorescence signals but similar lifetime values as compared to the raw Dox, whose fluorescence could be released by the addition of biothiol compound (such as glutathione). The cell viability results indicated that the Dox-Cu compound has a satisfactory killing effect on KYSE150 cells. The FLIM data showed that free doxorubicin was released from Dox-Cu complexes in cytoplasm of KYSE150 cells and then accumulated in the nucleus. After 90 min administration, the fluorescence lifetime signals reached 1.21 and 1.46 ns in the cytoplasm and nucleus, respectively, reflecting the transformation and transportation of Dox-Cu complexes. In conclusion, this work provides a satisfactory example for the research of prodrug monitored by FLIM techniques, expanding the useful applications of FLIM technique in drug development.


Assuntos
Antineoplásicos/metabolismo , Complexos de Coordenação/metabolismo , Doxorrubicina/metabolismo , Pró-Fármacos/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Cobre/química , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Humanos , Microscopia de Fluorescência , Pró-Fármacos/química , Pró-Fármacos/farmacologia
19.
Sensors (Basel) ; 18(8)2018 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-30103500

RESUMO

This paper presents a nondestructive test method to evaluate the residual bending strength of corroded reinforced concrete beam by analyzing the self-magnetic flux leakage (SMFL) signals. The automatic scanning device was equipped with a micromagnetic sensor and sensor-based experimental details were introduced. Next, the theoretical formula of the normal component HS(z) of the SMFL signal that originated from the corroded region was derived based on the magnetic dipole model and the experimental results were discussed. The results indicate that the experimental data of HS(z) are consistent with the theoretical calculations, both location and extent of the steel bars corrosion can be qualitatively determined by using HS(z). The gradient K of HS(z) is approximately linearly related to the loss rate, S, of the bending strength, which can be used to evaluate the residual bending strength of the corroded reinforced concrete beam. This work lays the foundation for evaluating the residual bending strength of corroded reinforced concrete beams using the SMFL signal; the micromagnetic sensor is further applied to the civil engineering.

20.
Sheng Wu Gong Cheng Xue Bao ; 32(6): 738-747, 2016 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-29019183

RESUMO

In this review, we presented the industrial status of biomanufactured polyhydroxyalkanoates (PHA), including poly (3-hydroxybutyrate) (PHB), poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P3/4HB)), and poly (3-hydroxybutyrate-3-hydroxycaproate) (PHBH). A lot of modification studies, aimed at solving problems of poor thermal stability, narrow processing window and other drawbacks of PHA, are discussed. The properties of PHA can be optimized by using proper modification method, in order to expand its applications.


Assuntos
Biotecnologia , Poli-Hidroxialcanoatos/química , Ácido 3-Hidroxibutírico , Hidroxibutiratos , Poliésteres
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA