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1.
Cancer Immunol Immunother ; 73(5): 95, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38607586

RESUMEN

BACKGROUND: Homologous recombination deficiency (HRD), though largely uncharacterized in clear cell renal cell carcinoma (ccRCC), was found associated with RAD51 loss of expression. PBRM1 is the second most common mutated genes in ccRCC. Here, we introduce a HRD function-based PBRM1-RAD51 ccRCC classification endowed with diverse immune checkpoint blockade (ICB) responses. METHODS: Totally 1542 patients from four independent cohorts were enrolled, including our localized Zhongshan hospital (ZSHS) cohort and Zhongshan hospital metastatic RCC (ZSHS-mRCC) cohort, The Cancer Genome Atlas (TCGA) cohort and CheckMate cohort. The genomic profile and immune microenvironment were depicted by genomic, transcriptome data and immunohistochemistry. RESULTS: We observed that PBRM1-loss ccRCC harbored enriched HRD-associated mutational signature 3 and loss of RAD51. Dual-loss of PBRM1 and RAD51 identified patients hyper-sensitive to immunotherapy. This dual-loss subtype was featured by M1 macrophage infiltration. Dual-loss was, albeit homologous recombination defective, with high chromosomal stability. CONCLUSIONS: PBRM1 and RAD51 dual-loss ccRCC indicates superior responses to immunotherapy. Dual-loss ccRCC harbors an immune-desert microenvironment but enriched with M1 macrophages. Dual-loss ccRCC is susceptible to defective homologous recombination but possesses high chromosomal stability.


Asunto(s)
Carcinoma de Células Renales , Carcinoma , Neoplasias Renales , Humanos , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/terapia , Inmunoterapia , Neoplasias Renales/genética , Neoplasias Renales/terapia , Inestabilidad Cromosómica , Microambiente Tumoral , Recombinasa Rad51 , Proteínas de Unión al ADN/genética , Factores de Transcripción/genética
2.
Int J Colorectal Dis ; 39(1): 108, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39008124

RESUMEN

BACKGROUND AND AIMS: Video-assisted anal fistula treatment (VAAFT) is an innovative surgical approach enabling the direct visualization of the fistula tract structure. This study aims to assess the efficacy of VAAFT in comparison with that of traditional surgical methods and explore potential risk factors contributing to fistula recurrence to provide new recommendations for surgical selection. MATERIALS AND METHODS: Information was collected from 100 patients with complex anal fistula (CAF) in our hospital who underwent surgical treatment from January 2021 to January 2023. We compared the baseline information and surgical outcomes of two groups, analyzed the risk factors for fistula recurrence by using logistic regression analysis, and conducted further exploration by using the body mass index. RESULTS: Equal numbers of patients underwent VAAFT and traditional surgeries, and no significant differences in baseline information were observed. Patients who received VAAFT experienced less intraoperative bleeding (15.5 (14.0-20.0) vs. 32.0 (25.0-36.0)), shorter hospital stays (2.0 (2.0-2.5) vs. 3.0 (3.0-3.5)), reduced postoperative pain and wound discharge, but longer operative times (43.3 ± 6.9 vs. 35.0 (31.5-40.0)) compared with patients who underwent traditional surgeries. No significant differences in recurrence rates were found three and six months after operation (the p-values were 0.790 and 0.806, respectively). However, the Wexner scores of the VAAFT group were significantly low in the first follow-up (0 (0-1.0) vs. 2.0 (1.0-2.0)). Postoperative recurrence of fistulas may be associated with obesity (p-value = 0.040), especially in patients undergoing traditional surgeries (p-value = 0.036). CONCLUSION: VAAFT offers advantages, such as less pain, less trauma, and faster recovery, compared with traditional surgical treatment. Obese patients with CAF are prone to recurrence, and we recommend that they undergo VAAFT treatment rather than traditional surgeries.


Asunto(s)
Obesidad , Fístula Rectal , Recurrencia , Cirugía Asistida por Video , Humanos , Fístula Rectal/cirugía , Fístula Rectal/etiología , Obesidad/complicaciones , Obesidad/cirugía , Femenino , Masculino , Resultado del Tratamiento , Persona de Mediana Edad , Adulto , Factores de Riesgo , Índice de Masa Corporal , Tempo Operativo , Tiempo de Internación
3.
Xenobiotica ; 54(5): 248-256, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38634734

RESUMEN

Prostate inflammation is often treated with drugs which are ineffective. Antibacterial agents fail to reach the prostate epithelium, and the blood-prostate barrier (BPB) may affect the drug transport process. Factors affecting drug efficacy remain unclear.Rats were categorised into groups A and B, corresponding to adulthood and puberty, respectively. Group C included the model of chronic prostate infection. Dialysates of levofloxacin and cefradine were collected from the prostate gland and jugular vein and evaluated. Pharmacokinetic analysis was conducted.The free concentrations of antimicrobials in the prostate and plasma samples of all groups peaked at 20 min, then gradually decreased. The mean AUC0-tprostate/AUC0-tplasma ratio in the levofloxacin group were 0.86, 0.53, and 0.95, and the mean values of AUC0-∞prostate/AUC0-∞plasma ratio were 0.85, 0.63, and 0.97. The corresponding values in the cefradine group were 0.67, 0.30 and 0.84, and 0.66, 0.31, and 0.85, respectively. The mean values in group B were lower than those in group A, and those in group C were higher than those in group B.The maturity of the prostate may affect the ability of the drug to cross the BPB. Infection may disrupt the BPB, affecting drug permeability.


Asunto(s)
Antibacterianos , Levofloxacino , Próstata , Masculino , Animales , Próstata/metabolismo , Ratas , Levofloxacino/farmacocinética , Antibacterianos/farmacocinética
4.
Nano Lett ; 23(3): 1109-1118, 2023 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-36716197

RESUMEN

Understanding physicochemical interactions and mechanisms related to the cell membranes of lives under extreme conditions is of essential importance but remains scarcely explored. Here, using a combination of computer simulations and experiments, we demonstrate that the structural integrity and controllable permeability of cell membranes at high temperatures are predominantly directed by configurational entropy emerging from distorted intermolecular organization of bipolar tethered lipids peculiar to the extremophiles. Detailed simulations across multiple scales─from an all-atom exploration of molecular mechanism to a mesoscale examination of its universal nature─suggest that this configurational entropy effect can be generalized to diverse systems, such as block copolymers. This offers biomimetic inspiration for designing heat-tolerant materials based on entropy, as validated by our experiments of synthetic polymers. The findings provide new insight into the basic nature of the mechanism underlying the adaptation of organisms to extreme conditions and might open paths for designed materials inspired by entropic effects in biological systems.


Asunto(s)
Extremófilos , Entropía , Simulación por Computador , Membrana Celular
5.
J Sci Food Agric ; 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39150228

RESUMEN

BACKGROUND: Rice bran, a by-product of rice processing, has not been fully utilized except for the small amount used for raising animals. The raw material source requirements of microcrystalline cellulose are becoming increasingly extensive. However, the characteristics of preparing microcrystalline cellulose from rice bran have not been reported, which limits the application of rice bran. RESULTS: Microcrystalline cellulose was obtained from rice bran by alkali treatment, delignification, bleaching and acid hydrolysis. The morphology, particle size distribution, degree of polymerization, crystallinity, and thermal stability of rice bran microcrystalline cellulose were analyzed. The chemical compositions, scanning electron microscopy and Fourier-transform infrared analysis for rice bran microcrystalline cellulose showed that the lignin and hemicellulose were successfully removed from the rice bran fiber matrix. The morphology of rice bran microcrystalline cellulose was shown to be of a short rod-shaped porous structure with an average diameter of 65.3 µm. The polymerization degree of rice bran microcrystalline cellulose was 150. The X-ray diffraction pattern of rice bran microcrystalline cellulose showed the characteristic peak of natural cellulose (type I), and its crystallization index was 71%. The rice bran microcrystalline cellulose may be used in biological composites with temperatures between 150 °C and 250 °C. CONCLUSION: These results suggest the feasibility of using rice bran as a low-price source of microcrystalline cellulose. © 2024 Society of Chemical Industry.

6.
PLoS Pathog ; 17(11): e1010034, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34762717

RESUMEN

Siglec-9 is an MHC-independent inhibitory receptor expressed on a subset of natural killer (NK) cells. Siglec-9 restrains NK cytotoxicity by binding to sialoglycans (sialic acid-containing glycans) on target cells. Despite the importance of Siglec-9 interactions in tumor immune evasion, their role as an immune evasion mechanism during HIV infection has not been investigated. Using in vivo phenotypic analyses, we found that Siglec-9+ CD56dim NK cells, during HIV infection, exhibit an activated phenotype with higher expression of activating receptors and markers (NKp30, CD38, CD16, DNAM-1, perforin) and lower expression of the inhibitory receptor NKG2A, compared to Siglec-9- CD56dim NK cells. We also found that levels of Siglec-9+ CD56dim NK cells inversely correlate with viral load during viremic infection and CD4+ T cell-associated HIV DNA during suppressed infection. Using in vitro cytotoxicity assays, we confirmed that Siglec-9+ NK cells exhibit higher cytotoxicity towards HIV-infected cells compared to Siglec-9- NK cells. These data are consistent with the notion that Siglec-9+ NK cells are highly cytotoxic against HIV-infected cells. However, blocking Siglec-9 enhanced NK cells' ability to lyse HIV-infected cells, consistent with the known inhibitory function of the Siglec-9 molecule. Together, these data support a model in which the Siglec-9+ CD56dim NK subpopulation is highly cytotoxic against HIV-infected cells even whilst being restrained by the inhibitory effects of Siglec-9. To harness the cytotoxic capacity of the Siglec-9+ NK subpopulation, which is dampened by Siglec-9, we developed a proof-of-concept approach to selectively disrupt Siglec/sialoglycan interactions between NK and HIV-infected cells. We achieved this goal by conjugating Sialidase to several HIV broadly neutralizing antibodies. These conjugates selectively desialylated HIV-infected cells and enhanced NK cells' capacity to kill them. In summary, we identified a novel, glycan-based interaction that may contribute to HIV-infected cells' ability to evade NK immunosurveillance and developed an approach to break this interaction.


Asunto(s)
Antígenos CD/metabolismo , Antígeno CD56/inmunología , Infecciones por VIH/patología , VIH/fisiología , Células Asesinas Naturales/inmunología , Lectinas Similares a la Inmunoglobulina de Unión a Ácido Siálico/metabolismo , Carga Viral , Viremia/patología , Antígenos CD/genética , Infecciones por VIH/inmunología , Infecciones por VIH/metabolismo , Infecciones por VIH/virología , Humanos , Células Asesinas Naturales/metabolismo , Lectinas Similares a la Inmunoglobulina de Unión a Ácido Siálico/genética , Viremia/inmunología , Viremia/metabolismo , Viremia/virología
7.
Anticancer Drugs ; 33(2): 142-148, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-34561997

RESUMEN

Sperm-associated antigen 9 (SPAG9) is closely related to the growth and metastasis of advanced prostate cancer. Docetaxel (DTX) is the gold standard for chemotherapy of prostate cancer, but its side effects decrease the life quality of patients. Therefore, it is urgent to develop combination therapy to increase chemotherapy efficacy for advanced prostate cancer. Oncolytic adenovirus carrying a short hairpin RNA (shRNA) targeting SPAG9 (ZD55-shSPAG9) was applied alone or in combination with docetaxel in prostate cancer cells. Cells were analyzed by cell counting kit-8, Hocehst-33258, transwell and western blot analysis. For in vivo experiments, nude mice were loaded with prostate cancer cells. ZD55-shSPAG9 effectively silenced the expression of SPAG9 in prostate cancer cells in vitro and in vivo. The replication of ZD55-shSPAG9 in prostate cancer cells was not affected by docetaxel, but the combined use of ZD55-shSAPAG9 and docetaxel has a better inhibitory effect on tumor growth and invasion in vitro and in vivo. Our study showed that the combined use of ZD55-shSPAG9 and docetaxel may be a new approach to the treatment of advanced prostate cancer.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/efectos de los fármacos , Antineoplásicos/farmacología , Docetaxel/farmacología , Viroterapia Oncolítica/métodos , Neoplasias de la Próstata/tratamiento farmacológico , Adenoviridae , Animales , Antineoplásicos/administración & dosificación , Docetaxel/administración & dosificación , Combinación de Medicamentos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neoplasias de la Próstata/patología , ARN Interferente Pequeño/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Nano Lett ; 21(19): 8439-8446, 2021 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-34591482

RESUMEN

The densest packings of identical spherical colloidal nanocrystals in a thin cylinder generally give rise to confinement-induced chiral ordering. Here, we demonstrate that entropy can invalidate Pauling's packing rules for the nanocrystals confined in wide cylinders and novel ordered phases, where chiral ordering is broken, emerge. The nucleation and growth of spherical colloidal nanocrystals in the wide cylinders exhibit unique mechanisms which are distinctly different from that of thin ones. Furthermore, theoretical models which capture the essential physics of the ordering transitions are developed to reproduce the achiral ordering and reveal that the ordered phases are thermodynamically stable and stabilized through confinement-mediated entropic effect. These findings demonstrate that entropy arising from thermal motion can invalidate Pauling's packing rules of spherical colloidal nanocrystals confined in cylinders, which provides new insights into confinement physics of colloidal particles and might inspire nonintuitive design rules for the fabrication of novel ordered phases through confinement.

9.
Infect Immun ; 89(10): e0072820, 2021 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-34152830

RESUMEN

Malaria infects millions of people every year, and despite recent advances in controlling disease spread, such as vaccination, it remains a global health concern. The circumsporozoite protein (CSP) has long been acknowledged as a key target in antimalarial immunity. Leveraging the DNA vaccine platform against this formidable pathogen, the following five synthetic DNA vaccines encoding variations of CSP were designed and studied: 3D7, GPI1, ΔGPI, TM, and DD2. Among the single CSP antigen constructs, a range of immunogenicity was observed with ΔGPI generating the most robust immunity. In an intravenous (i.v.) sporozoite challenge, the best protection among vaccinated mice was achieved by ΔGPI, which performed almost as well as the monoclonal antibody 311 (MAb 311) antibody control. Further analyses revealed that ΔGPI develops high-molecular-weight multimers in addition to monomeric CSP. We then compared the immunity generated by ΔGPI versus synDNA mimics for the antimalaria vaccines RTS,S and R21. The anti-CSP antibody responses induced were similar among these three immunogens. T cell responses demonstrated that ΔGPI induced a more focused anti-CSP response. In an infectious mosquito challenge, all three of these constructs generated inhibition of liver-stage infection as well as immunity from blood-stage parasitemia. This study demonstrates that synDNA mimics of complex malaria immunogens can provide substantial protection as can a novel synDNA vaccine ΔGPI.


Asunto(s)
Inmunogenicidad Vacunal/inmunología , Vacunas contra la Malaria/inmunología , Malaria Falciparum/inmunología , Malaria/inmunología , Proteínas Protozoarias/inmunología , Vacunas Sintéticas/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Antiprotozoarios/inmunología , Línea Celular , Modelos Animales de Enfermedad , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Plasmodium berghei/inmunología , Plasmodium falciparum/inmunología , Esporozoítos/inmunología , Vacunación/métodos
10.
J Am Chem Soc ; 143(41): 17250-17260, 2021 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-34618447

RESUMEN

Nonbactericidal polymers that prevent bacterial attachment are important for public health, environmental protection, and avoiding the generation of superbugs. Here, inspired by the physical bactericidal process of carbon nanotubes and graphene derivatives, we develop nonbactericidal polymers resistant to bacterial attachment by using multicomponent reactions (MCRs) to introduce molecular "needles" (rigid aliphatic chains) and molecular "razors" (multicomponent structures) into polymer side chains. Computer simulation reveals the occurrence of spontaneous entropy-driven interactions between the bacterial bilayers and the "needles" and "razors" in polymer structures and provides guidance for the optimization of this type of polymers for enhanced resistibility to bacterial attachment. The blending of the optimized polymer with commercially available polyurethane produces a film with remarkably superior stability of the resistance to bacterial adhesion after wear compared with that of commercial mobile phone shells made by the Sharklet technology. This proof-of-concept study explores entropy-driven polymers resistant to bacterial attachment via a combination of MCRs, computer simulation, and polymer chemistry, paving the way for the de novo design of nonbactericidal polymers to prevent bacterial contamination.


Asunto(s)
Polímeros
11.
Macromol Rapid Commun ; 42(9): e2100010, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33634531

RESUMEN

Water-resistant and high-strength adhesion on different surfaces has attracted considerable attention for decades. However, the adhesion performances of conventional adhesives suffer from deterioration in adhesion performances under water or wet conditions. This work proposes a dipole-dipole interaction strategy for fabricating a solvent-free adhesive that is synthesized via simple one-step copolymerization of dipole monomer acrylonitrile (AN), crosslinker poly(ethylene glycol) diacrylate (PEGDA) with variable length, and a monomer-soluble initiator that initiates room-temperature polymerization. The dipole-dipole interactions from cyan groups in AN concurrently contribute to strong cohesion and adhesion strength in bonding to a wide range of substrates including aluminum, ceramic, glass fiber, epoxy resin, polyethylene terephthalate, wood, and fractured large segmental bone. The adhesion strengths are dependent upon the length of PEGDA, and the shorter PEGDA-crosslinked PAN adhesive demonstrates outstanding water-resistant adhesion spanning pH 2 to pH 10 for 30 days with adhesion strength ranging from 3.31 to 3.97 MPa due to strong dipole-dipole pairing shielding. This dipole-dipole interaction and co-dissolution strategy open a new avenue for creating high-strength water-resistant adhesives for promising applications in engineering and hard-tissue repair.


Asunto(s)
Adhesivos , Agua , Resinas Epoxi , Ensayo de Materiales , Polimerizacion , Solventes
12.
Pediatr Dermatol ; 38(4): 982-983, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34145911

RESUMEN

Subcutaneous fat necrosis (SCFN) is an inflammatory disorder of the adipose tissue that commonly presents in neonates as tender subcutaneous nodules on the trunk and extremities with hypercalcemia as a potential complication. We report the case of a 3-month-old female who presented with circular alopecia of the scalp and was found to have histopathologically confirmed SCFN. Recognition of SCFN as a cause for alopecia in young infants may allow prompt screening for hypercalcemia and reduce the risk for associated morbidity and mortality.


Asunto(s)
Necrosis Grasa , Hipercalcemia , Alopecia/diagnóstico , Alopecia/etiología , Necrosis Grasa/complicaciones , Necrosis Grasa/diagnóstico , Femenino , Humanos , Lactante , Recién Nacido , Necrosis , Grasa Subcutánea
13.
Nano Lett ; 20(8): 5616-5624, 2020 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-32697100

RESUMEN

Entropy, one of the central concepts of thermodynamics, can be a predominant contribution to structural formation and transition. Although it is well-known that diverse forces and energies can significantly contribute to the structures and activities at bio-nano interfaces, the potential entropic contribution remains less well understood. Therefore, this review article seeks to provide a conceptual framework demonstrating that entropy can be exploited to shape the physicochemical properties of bio-nano interfaces and thereby regulate the structures, responses, and functions of biological systems. We introduce the typical types of entropy that matter at bio-nano interfaces. Moreover, some key characteristics featuring entropy at bio-nano interfaces, such as the difference between entropic force and energetic interaction and the associated implications for biomimetic research, are discussed. We expect that this review could stimulate further effort in the fundamental research of entropy in biology and in the biological applications of entropic effects in designer biomaterials.


Asunto(s)
Entropía
14.
J Clin Microbiol ; 58(11)2020 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-32855181

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic of COVID-19, resulting in cases of mild to severe respiratory distress and significant mortality. The global outbreak of this novel coronavirus has now infected >20 million people worldwide, with >5 million cases in the United States (11 August 2020). The development of diagnostic and research tools to determine infection and vaccine efficacy is critically needed. We have developed multiple serologic assays using newly designed SARS-CoV-2 reagents for detecting the presence of receptor-binding antibodies in sera. The first assay is surface plasmon resonance (SPR) based and can quantitate both antibody binding to the SARS-CoV-2 spike protein and blocking to the Angiotensin-converting enzyme 2 (ACE2) receptor in a single experiment. The second assay is enzyme-linked immunosorbent assay (ELISA) based and can measure competition and blocking of the ACE2 receptor to the SARS-CoV-2 spike protein with antispike antibodies. The assay is highly versatile, and we demonstrate the broad utility of the assay by measuring antibody functionality of sera from small animals and nonhuman primates immunized with an experimental SARS-CoV-2 vaccine. In addition, we employ the assay to measure receptor blocking of sera from SARS-CoV-2-infected patients. The assay is shown to correlate with pseudovirus neutralization titers. This type of rapid, surrogate neutralization diagnostic can be employed widely to help study SARS-CoV-2 infection and assess the efficacy of vaccines.


Asunto(s)
Anticuerpos Bloqueadores/sangre , Betacoronavirus/inmunología , Técnicas de Laboratorio Clínico , Infecciones por Coronavirus/diagnóstico , Peptidil-Dipeptidasa A/inmunología , Neumonía Viral/diagnóstico , Enzima Convertidora de Angiotensina 2 , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Betacoronavirus/aislamiento & purificación , COVID-19 , Prueba de COVID-19 , Vacunas contra la COVID-19 , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Ensayo de Inmunoadsorción Enzimática , Cobayas , Humanos , Inmunoglobulina G/sangre , Ratones , Pruebas de Neutralización , Pandemias , Neumonía Viral/sangre , Neumonía Viral/inmunología , Primates , Conejos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/inmunología , Resonancia por Plasmón de Superficie , Vacunas Virales/administración & dosificación , Vacunas Virales/inmunología
15.
Phys Rev Lett ; 124(19): 198102, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32469587

RESUMEN

Active particles are widely recognized to potentially revolutionize technologies in numerous biomedical applications. However, the physical origin behind cellular uptake of these particles in the nonequilibrium state remains scarcely understood. Here we combine Brownian dynamics simulation as well as theoretical analysis to provide the criterion for cellular uptake of active particles, related to various physical attributes. Upon enhancing the activity, the uptake efficiency for the active particles with tilted orientation is examined to be nonmonotonic, in stark contrast to the monotonic dependence for active particles orientated normally to the membrane. This can be attributed to the interplay between membrane adhesion energy and kinetic energy of active particles, resulting in unique kinetic pathways. Furthermore, a theoretical model that captures the essential physics of the cellular endocytosis process is developed to reproduce this nonmonotonic feature. The results are of immediate interest to understand and tune activity-mediated cellular interaction and internalization of such emerging colloids.


Asunto(s)
Membrana Celular/metabolismo , Lípidos/farmacocinética , Modelos Biológicos , Membrana Celular/química , Simulación por Computador , Lípidos/química , Tamaño de la Partícula
16.
Soft Matter ; 16(16): 3869-3881, 2020 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-32236197

RESUMEN

Diffusion is an essential and fundamental means of transport of substances on cell membranes, and the dynamics of biomembranes plays a crucial role in the regulation of numerous cellular processes. The understanding of the complex mechanisms and the nature of particle diffusion have a bearing on establishing guidelines for the design of efficient transport materials and unique therapeutic approaches. Herein, this review article highlights the most recent advances in investigating diffusion dynamics of nanoscale objects on biological membranes, focusing on the approaches of tailored computer simulations and theoretical analysis. Due to the presence of the complicated and heterogeneous environment on native cell membranes, the diffusive transport behaviors of nanoparticles exhibit unique and variable characteristics. The general aspects and basic theories of normal diffusion and anomalous diffusion have been introduced. In addition, the influence of a series of external and internal factors on the diffusion behaviors is discussed, including particle size, membrane curvature, particle-membrane interactions or particle-inclusion, and the crowding degree of membranes. Finally, we seek to identify open problems in the existing experimental, simulation, and theoretical research studies, and to propose challenges for future development.


Asunto(s)
Membrana Celular/metabolismo , Modelos Biológicos , Nanoestructuras/administración & dosificación , Simulación por Computador , Difusión , Humanos , Fosfolípidos/metabolismo
17.
Med Sci Monit ; 26: e926807, 2020 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-33199674

RESUMEN

BACKGROUND The neuroinflammation of paraventricular nucleus (PVN) of the hypothalamus has been implicated in the development of hypertension. The promoted invasion of peripheral immune cells into PVN may be attributed to the upregulation of chemokines, then exacerbating neuroinflammation. We studied the expressions of chemokines, activation of microglial cells, and inflammatory mediators in PVN of rats with stress-induced hypertension (SIH). MATERIAL AND METHODS SIH was induced by electrical foot shock combined with noise for 2 h twice a day, at an interval of 4 h for 14 consecutive days. At the end of the 14th day, fresh PVN tissues were collected to measure the expressions of chemokines using the RayBiotech antibody array. RESULTS We are the first to report that the expression of CXCL7 was extremely high in PVN of control rats, and was significantly lower in SIH rats. The expressions of CCL2 and CX3CL1 in PVN of SIH rats significantly exceeded those of control rats. The numbers of CX3CR1 (receptor of CX3CL1)-immunostained cells and oxycocin-42 (OX-42, marker of microglia)-positive cells increased in PVN of the SIH rats. The stress enhanced the protein expressions of proinflammatory cytokines IL-6 and IL-17 and reduced those of anti-inflammatory cytokines TGF-ß and IL-10 in PVN. CONCLUSIONS In PVN of SIH rats, chronic stress induced neuroinflammation characterized by the activated microglia and upregulated proinflammatory cytokines. Expressions of chemokines CXCL7, CX3CL1, and CCL2 were altered. The causal link of chemokines to PVN neuroinflammation and hypertension remain to be determined.


Asunto(s)
Quimiocinas/genética , Hipertensión/etiología , Hipertensión/genética , Núcleo Hipotalámico Paraventricular/patología , Estrés Psicológico/complicaciones , Regulación hacia Arriba/genética , Animales , Presión Sanguínea/fisiología , Quimiocinas/metabolismo , Frecuencia Cardíaca/fisiología , Hipertensión/fisiopatología , Mediadores de Inflamación/metabolismo , Masculino , Microglía/patología , Núcleo Hipotalámico Paraventricular/fisiopatología , Ratas Sprague-Dawley , Estrés Psicológico/fisiopatología
18.
Angew Chem Int Ed Engl ; 59(18): 7106-7112, 2020 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-32059069

RESUMEN

Active media that host spiral waves can display complex modes of locomotion driven by the dynamics of those waves. We use a model of a photosensitive stimulus-responsive gel that supports the propagation of spiral chemical waves to study locomotive transition and programmed locomotion. The mode transition between circular and toroidal locomotion results from the onset of spiral tip meandering that arises via a secondary Hopf bifurcation as the level of illumination is increased. This dynamic instability of the system introduces a second circular locomotion with a small diameter caused by tip meandering. The original circular locomotion with large diameter is driven by the push-pull asymmetry of the wavefront and waveback of the simple spiral waves initiated at one corner of gel. By harnessing this mode transition of the gel locomotion via coded illumination, we design programmable pathways of nature-inspired angular locomotion of the gel.

19.
Acc Chem Res ; 51(4): 900-909, 2018 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-29589915

RESUMEN

The ability to tailor the interfacial behaviors of nanoparticles (NPs) is crucial not only for the design of novel nanostructured materials with superior properties and of interest for many promising applications such as water purification, enhanced oil recovery, and innovative energy transduction, but also for a better insight into many biological systems where nanoscale particles such as proteins or viruses can interact and organize at certain interfaces. As a class of emerging building blocks, Janus NPs consisting of two compartments of different chemistry or polarity are ideal candidates to generate tunable and stable interfacial nanostructures because of the asymmetric nature. However, precise control over such interfacial nanostructures toward a controllable order and even responses to various external stimuli still remains a great challenge as the interfaces do not simply serve as a scaffold but rather induce complex enthalpic and entropic interactions. In this Account, we focus on our efforts on exploiting entropy strategies based on computational design to tailor the spatial distribution and ordering of NPs at the interfaces of various systems. First, we introduce the physical principle of entropic ordering, being the theoretical basis of entropy-directed interfacial self-assembly. The typical types of entropy, which have been harnessed to manipulate the interfacial NP organization, are then summarized, including conformational entropy, shape entropy, and rotational and vibrational entropy. Next, we describe the emerging pathways in the development of novel environmentally responsive systems which involve the use of entropy to access the stimuli-responsive behaviors of interfacial nanostructures. Taking one step further, how molecular architectures can be tailored to tune the entropic contributions to the interfacial self-assembly is demonstrated, through identifying the effects of various intrinsic properties of block segments, such as chain length and stiffness, on entropy-governed precise organization of Janus NPs at block copolymer interfaces. Finally, we detail some key factors for tailoring interfacial organization through entropy. In summary, entropy strategies offer a promising and abundant framework for precisely programming the structural organization of NPs at interfaces. We discuss future directions to signify the framework in tailoring the interfacial organization of NPs. We hope that this Account will promote further efforts toward fundamental research and the wide applications of designed interfacial assemblies in new types of functional nanomaterials and beyond.


Asunto(s)
Entropía , Nanopartículas/química , Tamaño de la Partícula , Propiedades de Superficie
20.
Entropy (Basel) ; 21(2)2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33266901

RESUMEN

Polymer nanocomposite materials, consisting of a polymer matrix embedded with nanoscale fillers or additives that reinforce the inherent properties of the matrix polymer, play a key role in many industrial applications. Understanding of the relation between thermodynamic interactions and macroscopic morphologies of the composites allow for the optimization of design and mechanical processing. This review article summarizes the recent advancement in various aspects of entropic effects in polymer nanocomposites, and highlights molecular methods used to perform numerical simulations, morphologies and phase behaviors of polymer matrices and fillers, and characteristic parameters that significantly correlate with entropic interactions in polymer nanocomposites. Experimental findings and insight obtained from theories and simulations are combined to understand how the entropic effects are turned into effective interparticle interactions that can be harnessed for tailoring nanostructures of polymer nanocomposites.

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