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1.
Small ; 20(9): e2307585, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37849034

RESUMEN

The combination of multiple orthogonal interactions enables hierarchical complexity in self-assembled nanoscale materials. Here, efficient supramolecular polymerization of DNA origami nanostructures is demonstrated using a multivalent display of small molecule host-guest interactions. Modification of DNA strands with cucurbit[7]uril (CB[7]) and its adamantane guest, yielding a supramolecular complex with an affinity of order 1010 m-1 , directs hierarchical assembly of origami monomers into 1D nanofibers. This affinity regime enables efficient polymerization; a lower-affinity ß-cyclodextrin-adamantane complex does not promote extended structures at a similar valency. Finally, the utility of the high-affinity CB[7]-adamantane interactions is exploited to enable responsive enzymatic actuation of origami nanofibers assembled using peptide linkers. This work demonstrates the power of high-affinity CB[7]-guest recognition as an orthogonal axis to drive self-assembly in DNA nanotechnology.


Asunto(s)
Adamantano , Nanofibras , Nanoestructuras , Nanotecnología , ADN
2.
Hepatology ; 77(1): 124-143, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-35429173

RESUMEN

BACKGROUND AIMS: As a global health threat, NASH has been confirmed to be a chronic progressive liver disease that is strongly associated with obesity. However, no approved drugs or efficient therapeutic strategies are valid, mainly because its complicated pathological processes is underestimated. APPROACH RESULTS: We identified the RING-type E3 ubiquitin transferase-tripartite motif-containing protein 31 (TRIM31), a member of the E3 ubiquitin ligases family, as an efficient endogenous inhibitor of transforming growth factor-beta-activated kinase 1 (mitogen-activated protein kinase kinase kinase 7; MAP3K7), and we further confirmed that TRIM31 is an MAP3K7-interacting protein and promotes MAP3K7 degradation by enhancing ubiquitination of K48 linkage in hepatocytes. Hepatocyte-specific Trim31 deletion blocks hepatic metabolism homeostasis, concomitant with glucose metabolic syndrome, lipid accumulation, up-regulated inflammation, and dramatically facilitates NASH progression. Inversely, transgenic overexpression, lentivirus, or adeno-associated virus-mediated Trim31 gene therapy restrain NASH in three dietary mice models. Mechanistically, in response to metabolic insults, TRIM31 interacts with MAP3K7 and conjugates K48-linked ubiquitination chains to promote MAP3K7 degradation, thus blocking MAP3K7 abundance and its downstream signaling cascade activation in hepatocytes. CONCLUSIONS: TRIM31 may serve as a promising therapeutic target for NASH treatment and associated metabolic disorders.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Proteínas de Motivos Tripartitos , Ubiquitina-Proteína Ligasas , Animales , Ratones , Quinasas Quinasa Quinasa PAM/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/prevención & control , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación , Humanos , Proteínas de Motivos Tripartitos/metabolismo
3.
Altern Ther Health Med ; 30(1): 391-395, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37820664

RESUMEN

Objective: To explore the clinical effects of ultrasound-guided adductor block (UGAB) on postoperative analgesia after total knee replacement. Methods: From March 2022 to June 2022, 60 patients in the First Affiliated Hospital of Chongqing Medical University were included. They were divided into control (n = 30) and ultrasonic groups (n = 30). They all received total knee arthroplasty. Before total knee arthroplasty, patients in the control and ultrasonic groups underwent general anesthesia and UGAB, respectively. Visual Analogue Scale (VAS) was used to assess the pain. The time of the first straight leg elevation and the first landing time were recorded. Knee joint function was evaluated. Information about the dosage of tramadol intramuscular injection and the number of times patient-controlled analgesia pump pressing was collected. The serum levels of interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) were detected. Results: Compared with the control group, UGAB increased the rate of muscle contraction and relaxation and total and relaxation after total knee replacement in the ultrasonic group (P < .05). UGAB reduced VAS scores of pain during passive activity after operation (P < .05). UGAB also facilitated the first straight leg lifting time after the operation and the time of the first landing after the operation (P < .05). Meanwhile, UGAB reduced the dose of tramadol and press times of the self-control analgesia pump after operation (P < 0.05). UGAB also suppressed postoperative IL-6 and hs-CRP levels and increased postoperative joint range of motion (P < .05). Conclusion: UGAB promotes early recovery of knee function with high safety in patients undergoing total knee replacement, with reduced postoperative pain and inflammatory reaction.


Asunto(s)
Analgesia , Artroplastia de Reemplazo de Rodilla , Bloqueo Nervioso , Tramadol , Humanos , Tramadol/uso terapéutico , Proteína C-Reactiva , Interleucina-6 , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/prevención & control , Ultrasonografía Intervencional , Anestésicos Locales
4.
J Infect Dis ; 227(5): 675-685, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36546708

RESUMEN

BACKGROUND: Chronic hepatitis B is usually treated with nucleos(t)ide analogues (NAs). However, a cure is rarely achieved, even with years of treatment. Here, we investigated whether viral replication is completely halted and how long covalently closed circular DNA (cccDNA) persists in patients successfully treated with NAs. METHODS: A series of longitudinal serum samples and a collection of cross-sectional liver biopsies were obtained from patients successfully treated with NAs. Viral variants in serum HBV RNA were enumerated by deep sequencing. Viral replication intermediates in hepatocytes were directly visualized by in situ hybridization. The apparent half-life of each cccDNA was estimated. RESULTS: Three of 6 successfully treated patients demonstrated clear evidence of a small proportion of virus evolution, although the overwhelming proportion of variants were identical or possessed a similar degree of divergence through time. The apparent half-life of variants was estimated to be from approximately 7.42 weeks to infinite. Hepatocytes remained positive for cytoplasmic nucleocapsids-associated relaxed circular DNA in 4 of 7 liver needle biopsies. CONCLUSIONS: We conclude that even after prolonged treatment, a small proportion of the cccDNA reservoir is constantly replenished by continued low-level HBV replication, whereas a large proportion of the cccDNA reservoir persists over time.


Asunto(s)
Hepatitis B Crónica , Hepatitis B , Humanos , Hepatitis B Crónica/tratamiento farmacológico , Antivirales/uso terapéutico , Estudios Transversales , ADN Viral/genética , Virus de la Hepatitis B/genética , Replicación Viral , ADN Circular , Hepatitis B/tratamiento farmacológico
5.
J Am Chem Soc ; 145(21): 11745-11753, 2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37204420

RESUMEN

Herein, we report a highly efficient synthesis of enantioenriched aza-[3.3.1]-bicyclic enamines and ketones, a class of structural cores in many natural products, via asymmetric dearomatization of indoles with azodicarboxylates. The reaction is initiated by electrophilic amination and followed by aza-Prins cyclization/phenonium-like rearrangement. A newly developed fluorine-containing chiral phosphoric acid displays excellent activity in promoting this cascade reaction. The absence or presence of water as the additive directs the reaction pathway toward either enamine or ketone products in high yields (up to 93%) with high enantiopurity (up to 98% ee). Comprehensive density functional theory (DFT) calculations reveal the energy profile of the reaction and the origins of enantioselectivity and water-induced chemoselectivity.

6.
Biochem Biophys Res Commun ; 652: 46-54, 2023 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-36809704

RESUMEN

Substance addiction causes anxiety, which in turn reinforces the maintaining of substance use, resulting in a vicious circle. And this circle is one of the reasons why addiction is so hard to cure. However, there is no treatment involved in addiction-induced anxiety at present. We tested whether VNS (vagus nerve stimulation) can improve heroin-induced anxiety, and made a comparison between nVNS (transcervical vagus nerve stimulation) and taVNS (transauricular vagus nerve stimulation) on therapeutic effect. Mice were subjected to nVNS or taVNS before heroin administration. By observing c-Fos expression in the NTS (nucleus of the solitary tract), we assessed vagal fiber activation. Using the OFT (open field test) and the EPM (elevated cross maze test), we evaluated the anxiety-like behaviors of the mice. Using immunofluorescence, we observed the proliferation and activation of microglia in the hippocampus. And ELISA was used to measure the levels of proinflammatory factors in the hippocampus. Both nVNS and taVNS significantly increased the expression of c-Fos in the nucleus of solitary tract, suggesting the feasibility of nVNS and taVNS. The anxiety level of heroin-treated mice was significantly increased, microglia in the hippocampus was significantly proliferated and activated, and the proinflammatory factors (IL-1ß, IL-6, TNF-α) in the hippocampus were significantly up-regulated. Crucially, both nVNS and taVNS reversed the above changes caused by heroin addiction. SIGNIFICANCE: It was confirmed that the therapeutic effect of VNS on heroin-induced anxiety may be an effective treatment method to break the "addiction-anxiety" cycle and provides some insights for subsequent treatment of addiction.


Asunto(s)
Heroína , Estimulación del Nervio Vago , Ratones , Animales , Estimulación del Nervio Vago/métodos , Prótesis e Implantes , Hipocampo , Ansiedad , Nervio Vago/fisiología
7.
Inflamm Res ; 72(6): 1215-1235, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37314518

RESUMEN

BACKGROUND: Immune checkpoints negatively regulate immune response, thereby playing an important role in maintaining immune homeostasis. Substantial studies have confirmed that blockade or deficiency of immune checkpoint pathways contributes to the deterioration of autoimmune diseases. In this context, focusing on immune checkpoints might provide alternative strategies for the treatment of autoimmunity. Lymphocyte activation gene 3 (LAG3), as a member of immune checkpoint, is critical in regulating immune responses as manifested in multiple preclinical studies and clinical trials. Recent success of dual-blockade of LAG3 and programmed death-1 in melanoma also supports the notion that LAG3 is a crucial regulator in immune tolerance. METHODS: We wrote this review article by searching the PubMed, Web of Science and Google Scholar databases. CONCLUSION: In this review, we summarize the molecular structure and the action mechanisms of LAG3. Additionally, we highlight its roles in diverse autoimmune diseases and discuss how the manipulation of the LAG3 pathway can serve as a promising therapeutic strategy as well as its specific mechanism with the aim of filling the gaps from bench to bedside.


Asunto(s)
Enfermedades Autoinmunes , Neoplasias , Humanos , Activación de Linfocitos , Proteína del Gen 3 de Activación de Linfocitos , Antígenos CD/genética , Enfermedades Autoinmunes/terapia
8.
J Plan Lit ; 38(2): 187-199, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37153810

RESUMEN

Urban digital twins (UDTs) have been identified as a potential technology to achieve digital transformative positive urban change through landscape architecture and urban planning. However, how this new technology will influence community resilience and adaptation planning is currently unclear. This article: (1) offers a scoping review of existing studies constructing UDTs, (2) identifies challenges and opportunities of UDT technologies for community adaptation planning, and (3) develops a conceptual framework of UDTs for community infrastructure resilience. This article highlights the need for integrating multi-agent interactions, artificial intelligence, and coupled natural-physical-social systems into a human-centered UDTs framework to improve community infrastructure resilience.

9.
Artículo en Inglés | MEDLINE | ID: mdl-38274945

RESUMEN

Vacant urban land, although not officially designated as a green space, often exhibits a semi-wild natural state due to being left open to colonization by nature. Attention to the effects of vacant urban land on human health has increased due to both rising urban vacancy rates and non-communicable diseases (NCDs). However, relationships between many vacant land characteristics (such as vegetation coverage, size, duration, and location) and NCDs have not been comprehensively examined, especially comparing shrinking (depopulating) and growing (populating) cities. This study evaluates St. Louis, MO (shrinking), and Los Angeles, CA (growing) to explore these relationships using ordinary least squares (OLS) interaction analysis with a moderator approach. Results show that associations between vacancy rate, duration, location, and NCDs differ significantly between city types. Vegetation coverage and size are associated with specific NCDs, but there are no differences between city types. Unlike the largely dilapidated vacant lands in the shrinking city, which tend to harm public health, vacant lots in the growing city were more functional green spaces that can, in some cases, even mitigate NCDs. Interestingly, In St. Louis, the shorter the average duration of the vacant land, the greater the risk of NCDs in a shrinking city. This is because vacant land can be contagious to nearby lots if not treated, leading to more newly emerged vacant lands and reducing the average duration of vacant land. In such cases, census tracts with the lower duration of vacant lands in St. Louis tend to be areas facing persistent environmental degradation and high public health threats. Regarding location, vacant lands near industrial areas were linked to negative health outcomes in the Los Angeles (growing), while those near single-family and commercial areas posed higher risks of NCDs in the St Louis (shrinking). The findings aid decision-making for land supply regulation and regeneration as well as urban green space management to promote human health and well-being.

10.
Angew Chem Int Ed Engl ; 62(46): e202309820, 2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-37768737

RESUMEN

Two-dimensional (2D) imine-based covalent organic frameworks (COFs) hold potential for photocatalytic CO2 reduction. However, high energy barrier of imine linkage impede the in-plane photoelectron transfer process, resulting in inadequate efficiency of CO2 photoreduction. Herein, we present a dimensionality induced local electronic modulation strategy through the construction of one-dimensional (1D) pyrene-based covalent organic frameworks (PyTTA-COF). The dual-chain-like edge architectures of 1D PyTTA-COF enable the stabilization of aromatic backbones, thus reducing energy loss during exciton dissociation and thermal relaxation, which provides energetic photoelectron to traverse the energy barrier of imine linkages. As a result, the 1D PyTTA-COF exhibits significantly enhanced CO2 photoreduction activity under visible-light irradiation when coordinated with metal cobalt ion, yielding a remarkable CO evolution of 1003 µmol g-1 over an 8-hour period, which surpasses that of the corresponding 2D counterpart by a factor of 59. These findings present a valuable approach to address in-plane charge transfer limitations in imine-based COFs.

11.
Bioconjug Chem ; 33(12): 2262-2268, 2022 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-35802933

RESUMEN

The affinity possible from certain supramolecular motifs rivals that for some of the best-recognized interactions in biology. Cucurbit[7]uril (CB[7]) macrocycles, for example, are capable of achieving affinities in their binding to certain guests that rival that of biotin-avidin. Supramolecular host-guest recognition between CB[7] and certain guests has been demonstrated to spatially localize guest-linked agents to desired sites in vivo, offering opportunities to better exploit this affinity axis for applications in biomedicine. Herein, architectures of CB[7] are prepared from a polyamidoamine (PAMAM) dendrimer scaffold, installing a PEG-linked cholesterol anchor on the opposite end of the dendron to facilitate cell membrane integration. Cells are then modified with this dendritic CB[7] construct in vitro, demonstrating the ability to deliver a model guest-linked agent to the cell membrane. This approach to realize synthetic supramolecular "membrane receptors" may be leveraged in the future for in situ imaging or modulation of cell-based therapies or to facilitate a synthetic supramolecular recognition axis on the cell membrane.


Asunto(s)
Dendrímeros , Compuestos Macrocíclicos , Hidrocarburos Aromáticos con Puentes/química , Imidazoles/química , Compuestos Macrocíclicos/química , Membrana Celular
12.
Macromol Rapid Commun ; 43(23): e2200581, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35881763

RESUMEN

Spontaneous oxidative polymerization of dopamine (DA) is widely exploited as a facile and versatile method for surface modification. However, the reaction is very slow and only occurs in alkaline solutions, which severely limit its applications. Herein it is reported that the reaction can be dramatically accelerated by using Fe2+ as catalyst. While it takes hours and days using conventional method, the Fe2+ -catalyzed reaction finishes almost immediately at pH 7.0. In addition, under the catalysis of Fe2+ , the reaction can occur at a pH down to 4.0. The fast Fe2+ -catalyzed polymerization of DA leads to fast deposition of polydopamine (PDA) coating, thus allowing fast surface modification and textile dyeing. The Fe2+ -catalyzed reaction also allows spatial control over the PDA deposition. The fast, simple, and mild surface modification method developed here will find applications in numerous fields.


Asunto(s)
Dopamina , Polimerizacion , Catálisis
13.
Neoplasma ; 69(3): 620-629, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35263996

RESUMEN

Cholangiocarcinoma (CCA) is the second most common primary liver malignancy, however, it is difficult to diagnose and treat, and only a few patients with CCA are suitable for surgery. Iodine-125 (I-125) is an effective treatment for cancer, but the molecular mechanisms underlying the effects of I-125 differ among different cancers. This study aimed to explore the effects of I-125 on CCA cell activity and determine the possible mechanisms of action of I-125 in this type of cancer. CCA cell proliferation, cycling, apoptosis, autophagy, and endoplasmic reticulum (ER) stress were determined after irradiation of CCA cells with I-125 seeds. The effects of I-125 on autophagy and ER stress in three CCA cell lines were evaluated using western blotting, while the effects of I-125 on apoptosis and autophagy in QBC939 cells treated with si-Beclin1 or si-PERK, respectively, were assessed using flow cytometry. I-125 suppressed cell viability and induced cell cycle G2/M-phase arrest in three CCA cell lines (QBC939, TFK-1, HuCCT1). I-125 induced apoptosis, autophagy, and ER stress by altering the expression levels of some related proteins in each of the three CCA cell lines. Furthermore, autophagy inhibition (treatment with si-Beclin1) increased expression of apoptosis-related proteins (cleaved-PARP and cleaved-caspase-3, Bax/Bcl2) in QBC939 cells irradiated with I-125 seeds, while ER stress inhibition (with si-PERK) suppressed the expression of autophagy-related proteins (LC3-I, LC3-II, p62). Therefore, I-125 induces ER stress, thereby activating protective autophagy in CCA cells through the PERK signaling pathway. Combined inhibition of ER stress and autophagy signaling may increase the killing effect of I-125 on cancer cells and serve as a new auxiliary method in I-125 radiotherapy.


Asunto(s)
Neoplasias de los Conductos Biliares , Colangiocarcinoma , Apoptosis , Proteínas Reguladoras de la Apoptosis/metabolismo , Autofagia , Beclina-1/metabolismo , Neoplasias de los Conductos Biliares/radioterapia , Conductos Biliares Intrahepáticos/metabolismo , Línea Celular Tumoral , Colangiocarcinoma/radioterapia , Estrés del Retículo Endoplásmico , Humanos , Radioisótopos de Yodo/farmacología
14.
BMC Anesthesiol ; 22(1): 163, 2022 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-35619081

RESUMEN

BACKGROUND: This study explored the patient clinical characteristics that may affect electroconvulsive therapy (ECT) efficacy to enable improved focus during evaluations and preparation for ECT. METHODS: Patients were enrolled for ECT at the Department of Psychiatry and Anesthesiology of the First Affiliated Hospital of Chongqing Medical University from December 2017 to January 2019. The primary outcome in our study was defined as the development of nonremission. A multivariate logistic analysis was performed to identify the risk factors for nonremission. RESULTS: In total, 874 depressed patients were included in the study. After the ECT treatment, 255 cases (29.2%) exhibited nonremission. A multivariate logistic regression analysis of the variables was performed, and the results showed that atherosclerosis (OR 8.072, 95% CI 2.442 to 16.675; P = 0.001), COPD (OR 2.919, 95% CI 1.240 to 6.871; P = 0.014), diabetes (OR 2.202, 95% CI 1.115 to 4.348; P = 0.023) and smoking (OR 1.519, 95% CI 1.015 to 2.273; P = 0.042) were independent risk factors for nonremission. CONCLUSION: In the retrospective analysis, we found that atherosclerosis, diabetes, COPD and smoking may be high-risk factors for nonremission.


Asunto(s)
Aterosclerosis , Trastorno Depresivo Mayor , Terapia Electroconvulsiva , Enfermedad Pulmonar Obstructiva Crónica , Depresión , Trastorno Depresivo Mayor/tratamiento farmacológico , Humanos , Estudios Retrospectivos
15.
Tour Manag ; 92: 104533, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35431388

RESUMEN

This study analyzes a large-scale navigation dataset that captures travel activities of domestic inbound visitors in Jeju, Korea in the first nine months of 2020. A collection of regression models are introduced to quantify the dynamic effects of local and national COVID-19 indicators on their travel behavior. Results suggest that behavior of inbound travelers was jointly affected by pandemic severity locally and remotely. The daily number of new cases in Jeju has a greater impact on reducing travel activities than the national-level daily new cases of COVID-19. The impacts of the pandemic did not diminish over time but produced heterogeneous effects on travels with different trip purposes. Our findings reveal the persistence of COVID-19's effects on travel behavior and the variability in travelers' responses across tourism activities with different levels of perceived health risks. The implications for crisis management and recovery strategies are also discussed.

16.
Virol J ; 18(1): 147, 2021 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-34261488

RESUMEN

BACKGROUND: The clinical and virological course of patients with coronavirus disease 2019 (COVID-19) are lacking. We aimed to describe the clinical and virological characteristics of COVID-19 patients from 10 designated hospitals in 10 cities of Jiangsu province, China. The factors associated with the clearance of SARS-CoV-2 were investigated. METHODS: A total of 328 hospitalized patients with COVID-19 were retrospectively recruited. The epidemiological, clinical, laboratory, radiology and treatment data were collected. The associated factors of SARS-CoV-2 clearance were analyzed. RESULTS: The median duration of hospitalization was 16.0 days (interquartile range [IQR] 13.0-21.0 days). On multivariate Cox regression analysis, age > 60 years (hazard ratio [HR] 0.643, 95% confidence interval [CI] 0.454-0.911, P = 0.013) was associated with the delayed SARS-CoV-2 clearance, while the atomized inhalation of interferon α-2b could improve the clearance of SARS-CoV-2 (HR, 1.357, 95% CI 1.050-1.755, P = 0.020). Twenty-six (7.9%) patients developed respiratory failure and 4 (1.2%) patients developed ARDS. Twenty (6.1%) patients were admitted to the ICU, while no patient was deceased. CONCLUSIONS: Our study found that age > 60 years was associated with the delayed SARS-CoV-2 clearance, while treated with atomized inhalation of interferon α-2b could promote the clearance of SARS-CoV-2.


Asunto(s)
COVID-19/diagnóstico , SARS-CoV-2/fisiología , Adulto , Anciano , COVID-19/epidemiología , COVID-19/terapia , COVID-19/virología , China/epidemiología , Duración de la Terapia , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , SARS-CoV-2/genética , Esparcimiento de Virus , Adulto Joven
17.
Biomacromolecules ; 22(1): 171-182, 2021 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-32804483

RESUMEN

Host-guest physical cross-linking has been used to prepare supramolecular hydrogels for various biomedical applications. More recent efforts to endow these materials with stimuli-responsivity offers an opportunity to precisely tune their function for a target use. In the context of light-responsive materials, azobenzenes are one prevailing motif. Here, an asymmetric azobenzene was explored for its ability to form homoternary complexes with the cucurbit[8]uril macrocycle, exhibiting an affinity (Keq) of 6.21 × 1010 M-2 for sequential binding, though having negative cooperativity. Copolymers were first prepared from different and tunable ratios of NIPAM and DMAEA, and DMAEA groups were then postsynthetically modified with this asymmetric azobenzene. Upon macrocycle addition, these polymers formed supramolecular hydrogels; relaxation dynamics increased with temperature due to temperature-dependent affinity reduction for the ternary complex. Application of UV light disrupted the supramolecular motif through azobenzene photoisomerization, prompting a gel-to-sol transition in the hydrogel. Excitingly, within several minutes at room temperature, thermal relaxation of azobenzene to its trans state afforded rapid hydrogel recovery. By revealing this supramolecular motif and employing facile means for its attachment onto pre-synthesized polymers, the approach described here may further enable stimuli-directed control of supramolecular hydrogels for a number of applications.


Asunto(s)
Hidrogeles , Polímeros , Temperatura
18.
Biomacromolecules ; 22(8): 3565-3573, 2021 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-34314146

RESUMEN

Proteins are an impactful class of therapeutics but can exhibit suboptimal therapeutic performance, arising from poor control over the timescale of clearance. Covalent PEGylation is one established strategy to extend circulation time but often at the cost of reduced activity and increased immunogenicity. Supramolecular PEGylation may afford similar benefits without necessitating that the protein be permanently modified with a polymer. Here, we show that insulin pharmacokinetics can be modulated by tuning the affinity-directed dynamics of a host-guest motif used to non-covalently endow insulin with a poly(ethylene glycol) (PEG) chain. When administered subcutaneously, supramolecular PEGylation with higher binding affinities extends the time of total insulin exposure systemically. Pharmacokinetic modeling reveals that the extension in the duration of exposure arises specifically from decreased absorption from the subcutaneous depot governed directly by the affinity and dynamics of host-guest exchange. The lifetime of the supramolecular interaction thus dictates the rate of absorption, with negligible impact attributed to association of the PEG upon rapid dilution of the supramolecular complex in circulation. This modular approach to supramolecular PEGylation offers a powerful tool to tune protein pharmacokinetics in response to the needs of different disease applications.


Asunto(s)
Polietilenglicoles , Polímeros , Insulina , Proteínas
19.
Soft Matter ; 17(7): 1929-1939, 2021 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-33427280

RESUMEN

We present a method for using dynamic light scattering in the single-scattering limit to measure the viscoelastic moduli of soft materials. This microrheology technique only requires a small sample volume of 12 µL to measure up to six decades in time of rheological behavior. We demonstrate the use of dynamic light scattering microrheology (DLSµR) on a variety of soft materials, including dilute polymer solutions, covalently-crosslinked polymer gels, and active, biological fluids. In this work, we detail the procedure for applying the technique to new materials and discuss the critical considerations for implementing the technique, including a custom analysis script for analyzing data output. We focus on the advantages of applying DLSµR to biologically relevant materials: breast cancer cells encapsulated in a collagen gel and cystic fibrosis sputum. DLSµR is an easy, efficient, and economical rheological technique that can guide the design of new polymeric materials and facilitate the understanding of the underlying physics governing behavior of naturally derived materials.


Asunto(s)
Polímeros , Dispersión Dinámica de Luz , Geles , Reología , Viscosidad
20.
Acta Pharmacol Sin ; 42(9): 1437-1448, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33303990

RESUMEN

Aflibercept, as a soluble decoy vascular endothelial growth factor receptor, Which has been used as a first-line monotherapy for cancers. Aflibercept often causes cardiovascular toxicities including hypertension, but the mechanisms underlying aflibercept-induced hypertension remain unknown. In this study we investigated the effect of short-term and long-term administration of aflibercept on blood pressure (BP), vascular function, NO bioavailability, oxidative stress and endothelin 1 (ET-1) in mice and cultured endothelial cells. We showed that injection of a single-dose of aflibercept (18.2, 36.4 mg/kg, iv) rapidly and dose-dependently elevated BP in mice. Aflibercept treatment markedly impaired endothelial-dependent relaxation (EDR) and resulted in NADPH oxidases 1 (NOX1)- and NADPH oxidases 4 (NOX4)-mediated generation of ROS, decreased the activation of protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS) concurrently with a reduction in nitric oxide (NO) production and elevation of ET-1 levels in mouse aortas; these effects were greatly attenuated by supplementation of L-arginine (L-arg, 0.5 or 1.0 g/kg, bid, ig) before aflibercept injection. Similar results were observed in L-arg-pretreated cultured endothelial cells, showing markedly decreased ROS accumulation and AKT/eNOS/NO signaling impairment induced by aflibercept. In order to assess the effects of long-term aflibercept on hypertension and to evaluate the beneficial effects of L-arg supplementation, we administered these two drugs to WT mice for up to 14 days (at an interval of two days). Long-term administration of aflibercept resulted in a sustained increase in BP and a severely impaired EDR, which are associated with NOX1/NOX4-mediated production of ROS, increase in ET-1, inhibition of AKT/eNOS/NO signaling and a decreased expression of cationic amino acid transporter (CAT-1). The effects caused by long-term administration were greatly attenuated by L-arg supplementation in a dose-dependent manner. We conclude that aflibercept leads to vascular dysfunction and hypertension by inhibiting CAT-1/AKT/eNOS/NO signaling, increasing ET-1, and activating NOX1/NOX4-mediated oxidative stress, which can be suppressed by supplementation of L-arg. Therefore, L-arg could be a potential therapeutic agent for aflibercept-induced hypertension.


Asunto(s)
Arginina/farmacología , Hipertensión/inducido químicamente , Óxido Nítrico Sintasa de Tipo III/metabolismo , Óxido Nítrico/metabolismo , Proteínas Recombinantes de Fusión/efectos adversos , Enfermedades Vasculares/inducido químicamente , Animales , Aorta/metabolismo , Aorta/patología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Hipertensión/metabolismo , Hipertensión/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores de Factores de Crecimiento Endotelial Vascular , Proteínas Recombinantes de Fusión/farmacología , Transducción de Señal/efectos de los fármacos , Enfermedades Vasculares/metabolismo , Enfermedades Vasculares/fisiopatología
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