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1.
Artigo em Inglês | MEDLINE | ID: mdl-32240596

RESUMO

RATIONALE: Advances in neonatal critical care have greatly improved the survival of preterm infants but the long-term complications of prematurity, including Bronchopulmonary dysplasia (BPD), cause mortality and morbidity later in life. While Vascular Endothelial Growth Factor (VEGF) improves lung structure and function in rodent BPD models, severe side effects of VEGF therapy prevent its use in BPD patients. OBJECTIVES: To test whether nanoparticle delivery of proangiogenic transcription factors FOXM1 or FOXF1, both downstream targets of VEGF, can improve lung structure and function after neonatal hyperoxic injury. METHODS: Newborn mice were exposed to 75% O2 for 7 days of life before being returned to room air. On postnatal day 2, polyethylenimine-(5) myristic acid/ poly(ethylene glycol)-oleic acid/ cholesterol (PEI600-MA5/PEG-OA/Cho) nanoparticles containing non-integrating expression plasmids with Foxm1 or Foxf1 cDNAs were injected intravenously. The effects of the nanoparticles on lung structure and function were evaluated using confocal microscopy, flow cytometry and the Flexivent small animal ventilator. MAIN RESULTS: The nanoparticles efficiently targeted endothelial cells and myofibroblasts in the alveolar region. Nanoparticle delivery of either FOXM1 or FOXF1 did not protect endothelial cells from apoptosis caused by hyperoxia but increased endothelial proliferation and lung angiogenesis after the injury. FOXM1 and FOXF1 improved elastin fiber organization, decreased alveolar simplification and preserved lung function in mice reaching adulthood. CONCLUSIONS: Nanoparticle delivery of FOXM1 or FOXF1 stimulates lung angiogenesis and alveolarization during recovery from neonatal hyperoxic injury. Delivery of proangiogenic transcription factors has promise as a therapy for BPD in preterm infants.

2.
Theranostics ; 10(8): 3430-3450, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32206100

RESUMO

Reactive oxygen species (ROS) play a crucial role in cancer formation and development, especially cancer metastasis. However, lack of a precise tool, which could accurately distinguish specific types of ROS, restricts an in-depth study of ROS in cancer development and progression. Herein, we designed smart and versatile fluorescent Ag nanoclusters (AgNCs) for sensitive and selective detection of different species of ROS in cells and tissues. Methods: Firstly, dual-emission fluorescent AgNCs was synthesized by using bovine serum albumin (BSA) to sense different types of ROS (H2O2, O2•-, •OH). The responsiveness of the AgNCs to different species of ROS was explored by fluorescence spectrum, hydrodynamic diameter, and so on. Furthermore, dual-emission fluorescent AgNCs was used to sense ROS in tumor with different degrees of differentiation. Finally, the relationship between specific types of ROS and tumor cell invasion was explored by cell migration ability and the expression of cell adhesion and EMT markers. Results: This dual-emission fluorescent AgNCs possessed an excellent ability to sensitively and selectively distinguish highly reactive oxygen species (hROS, including O2•-and •OH) from moderate reactive oxygen species (the form of H2O2), and exhibited no fluoresence and green fluorescence, respectively. The emission of AgNCs is effective in detecting cellular and tissular ROS. When cultured with AgNCs, malignant tumor cells exhibit non-fluorescence, while the benign tumor emits green and reduced red light and the normal cells appear in weak green and bright red fluorescence. We further verified that not just H2O2 but specific species of ROS (O2•-and •OH) were involved in cell invasion and malignant transformation. Our study warrants further research on the role of ROS in physiological and pathophysiological processes. Conclusion: Taken together, AgNCs would be a promising approach for sensing ROS, and offer an intelligent tool to detect different kinds of ROS in tumors.

3.
ACS Appl Mater Interfaces ; 12(3): 4163-4173, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31891476

RESUMO

Engineering of cell surfaces holds promise in manipulating cellular activities in a physicochemical route as a complement to the biological approach. Mediated by Ca2+, a quick and convenient yet cytocompatible method is used to achieve surface engineering, by which polydopamine nanostructures can be in situ grown onto dendritic cell (DC) surfaces within 10 min. Ca2+, as the physical bridge between the negative cell surface and polydopamine, avoids the direct chemical polymerization of polydopamine onto the cell surface, critically important to maintain the cell viability. As a proof of concept in potential applications, this cell surface engineering shows a good control toward DC maturation. Upon surface polydopamine engineering, bone-marrow-derived DC exhibits a unique bidirectional control of maturation. The polydopamine structure enables effective suppression of DC activation by acting as an efficient scavenger of reactive oxygen species, a key signal during maturation. Conversely, an 808 nm laser irradiation can remotely relieve the suppressed state and effectively activate DC maturation by the photoheat effect of polydopamine (39 °C). The work provides an easily implemented, straightforward approach to achieve cell surface engineering, through which the DC maturation can be controlled.

4.
ACS Appl Mater Interfaces ; 12(4): 4193-4203, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31935069

RESUMO

Isolation of circulating tumor cells (CTCs) in peripheral blood from cancer patients bears critical importance for evaluation of therapeutic efficacy. The current CTC isolation strategies are majorly relying on either protein biomarkers or dimensional features of CTCs. In this study, we present a new methodology for CTC detection and isolation based on the surface charge of cancer cells, a bioelectrical manifestation of the "Warburg effect." Negative surface charge is a direct consequence of glycolysis of cancer cells, which can be utilized as an effective biophysical marker for CTC detection and isolation. Upon cancer cells-nanoparticle interaction via optimum incubation, serum protein-coated electrically charged nanoparticles can trap different cancer cells independent of their epithelial protein expression. In fetal bovine serum , the poly(ethyleneimine)-functionalized Fe3O4 nanoparticles, surface-decorated with protein corona, are able to efficiently capture CTCs from blood samples of colorectal cancer patients.  2-8 CTCs has been isolated from 1 mL of blood and identified by immunostaining fluorescence in situ hybridization and immunofluorescence staining in all 25 colorectal cancer patients at varied stages, while only 0-1 CTC was detected from blood samples of 10 healthy donors. Diverse CTC subpopulations of heteroploids and biomarker expression can also be detected in this strategy. The label-free, charge-based CTC method shows promise in cancer diagnosis and prognosis paving a new path for liquid biopsy.

5.
Stress ; 23(1): 87-96, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31311393

RESUMO

Psychological stress may be linked to cancer incidence; however, more direct evidence is required to support this viewpoint. In this study, we investigated the effects of stress on immunosurveillance against cancer cells using a previously established examination stress model. We showed that the cancer killing activity (CKA) of granulocytes (also known as polymorphic nuclear cells, PMNs) is sharply reduced during examination stress stimulation in some donors who are psychologically sensitive to examination stress, with the concentration of plasma stress hormones (cortisone, epinephrine, and norepinephrine) increasing accordingly. The effects of stress hormones on immune cell CKA were also investigated under two in vitro co-incubation conditions, with all three hormones found to exert inhibitory effects on the CKA of PMNs and mononuclear cells. We showed that stress triggered the release of stress hormones which had profound inhibitory effects on the innate anticancer functions of PMNs. These results provide a possible explanation for the relationship between psychological stress and cancer incidence.

6.
ACS Appl Mater Interfaces ; 11(51): 47750-47761, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31773939

RESUMO

Remodeling of cellular surfaces is shown highly effective in the manipulation and control of cell behaviors via nonbiological means. By 5-thio-2-nitrobenzoate-mediated, fast, and reversible disulfide-thiol exchange, a sequential layer by layer assembly process was developed to grow albumin protein shells on cellular surfaces fixed by a disulfide-linked network, in a cytocompatible manner. The artificial shells, accomplished by a double-assembly process, were sustainable up to >1 day, and thereafter gradually bioabsorbed with unaffected cell viability. The surface engineering process enabled dynamic remodeling of cellular surfaces that effectively controlled cell behaviors including regulated cell proliferation, enhanced uptake efficiency of dextran-fluorescein isothiocyanate that is known for cell-impermeability, and targeted imaging. This unique approach was well-validated on tumor cells (B16), immune cells (DC2.4), and neutrophils, showing its potential universality for most of the cells that are rich in thiols. The new strategy will show promise in cell manipulation and targeted imaging.

7.
Biomater Sci ; 7(12): 5238-5246, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31602440

RESUMO

Due to unsatisfactory tumor-targeting efficiency, hitch-hiking nanomedicines with tumor "smelling" immune cells have rapidly evolved to achieve a more precision delivery. However, the current research tends to default to the smelling capacity of neutrophils and largely overlooks the capacity of those immune cells that are heavily dependent on the pathogen exposure history of individuals. By avoiding risky strategies, such as altering the housing environment of mice for the improved activity of immune cells, we propose a new concept of nano-immunotraining strategy to quickly activate neutrophil tumor tropism and thereby give an enhanced tumor-targeting capacity. Such a strategy involves a facile construction of a vaccine-like nano-CpG adjuvant, followed by pre-immunizing on mice periodically to mimic the pathogen exposure. The results demonstrated that a significantly enhanced tumor-targeting accumulation of neutrophils harvested from nano-immunotrained mice could be achieved, either by intraperitoneal or intravenous injection. This easily accessed, reproducible, and biosafe nano-immunotraining strategy holds a great promise for more precision delivery of nanomedicines.

8.
Am J Respir Crit Care Med ; 200(8): 1045-1056, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31199666

RESUMO

Rationale: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal congenital disorder causing respiratory failure and pulmonary hypertension shortly after birth. There are no effective treatments for ACDMPV other than lung transplant, and new therapeutic approaches are urgently needed. Although ACDMPV is linked to mutations in the FOXF1 gene, molecular mechanisms through which FOXF1 mutations cause ACDMPV are unknown.Objectives: To identify molecular mechanisms by which S52F FOXF1 mutations cause ACDMPV.Methods: We generated a clinically relevant mouse model of ACDMPV by introducing the S52F FOXF1 mutation into the mouse Foxf1 gene locus using CRISPR/Cas9 technology. Immunohistochemistry, whole-lung imaging, and biochemical methods were used to examine vasculature in Foxf1WT/S52F lungs and identify molecular mechanisms regulated by FOXF1.Measurements and Main Results: FOXF1 mutations were identified in 28 subjects with ACDMPV. Foxf1WT/S52F knock-in mice recapitulated histopathologic findings in ACDMPV infants. The S52F FOXF1 mutation disrupted STAT3-FOXF1 protein-protein interactions and inhibited transcription of Stat3, a critical transcriptional regulator of angiogenesis. STAT3 signaling and endothelial proliferation were reduced in Foxf1WT/S52F mice and human ACDMPV lungs. S52F FOXF1 mutant protein did not bind chromatin and was transcriptionally inactive. Furthermore, we have developed a novel formulation of highly efficient nanoparticles and demonstrated that nanoparticle delivery of STAT3 cDNA into the neonatal circulation restored endothelial proliferation and stimulated lung angiogenesis in Foxf1WT/S52F mice.Conclusions: FOXF1 acts through STAT3 to stimulate neonatal lung angiogenesis. Nanoparticle delivery of STAT3 is a promising strategy to treat ACDMPV associated with decreased STAT3 signaling.

9.
Nanoscale ; 11(2): 587-597, 2019 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-30556557

RESUMO

In the current study, we describe a novel DNA sensor system for specific and quantitative detection of mycobacteria, which is the causative agent of tuberculosis. Detection is achieved by using the enzymatic activity of the mycobacterial encoded enzyme topoisomerase IA (TOP1A) as a biomarker. The presented work is the first to describe how the catalytic activities of a member of the type IA family of topoisomerases can be exploited for specific detection of bacteria. The principle for detection relies on a solid support anchored DNA substrate with dual functions namely: (1) the ability to isolate mycobacterial TOP1A from crude samples and (2) the ability to be converted into a closed DNA circle upon reaction with the isolated enzyme. The DNA circle can act as a template for rolling circle amplification generating a tandem repeat product that can be visualized at the single molecule level by fluorescent labelling. This reaction scheme ensures specific, sensitive, and quantitative detection of the mycobacteria TOP1A biomarker as demonstrated by the use of purified mycobacterial TOP1A and extracts from an array of non-mycobacteria and mycobacteria species. When combined with mycobacteriophage induced lysis as a novel way of effective yet gentle extraction of the cellular content from the model Mycobacterium smegmatis, the DNA sensor system allowed detection of mycobacteria in small volumes of cell suspensions. Moreover, it was possible to detect M. smegmatis added to human saliva. Depending on the composition of the sample, we were able to detect 0.6 or 0.9 million colony forming units (CFU) per mL of mycobacteria, which is within the range of clinically relevant infection numbers. We, therefore, believe that the presented assay, which relies on techniques that can be adapted to limited resource settings, may be the first step towards the development of a new point-of-care diagnostic test for tuberculosis.


Assuntos
Proteínas de Bactérias/análise , Técnicas Biossensoriais/métodos , DNA Topoisomerases Tipo I/análise , Ácidos Nucleicos Imobilizados/metabolismo , Mycobacterium/isolamento & purificação , Patologia Molecular/métodos , Proteínas de Bactérias/metabolismo , Biomarcadores/análise , Biomarcadores/metabolismo , DNA Topoisomerases Tipo I/isolamento & purificação , DNA Topoisomerases Tipo I/metabolismo , Corantes Fluorescentes/química , Humanos , Ácidos Nucleicos Imobilizados/química , Mycobacterium/enzimologia , Sensibilidade e Especificidade
10.
Adv Healthc Mater ; 7(23): e1800876, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30398703

RESUMO

Pulmonary vascular disease encompasses a wide range of serious afflictions with important clinical implications. There is critical need for the development of efficient, nonviral gene therapy delivery systems. Here, a promising avenue to overcome critical issues in efficient cell targeting within the lung via a uniquely designed nanosystem is reported. Polyplexes are created by functionalizing hyperbranched polyethylenimine (PEI) with biological fatty acids and carboxylate-terminated poly(ethylene glycol) (PEG) through a one-pot 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide reaction. Following intravenous injection, polyplexes show an exceptionally high specificity to the pulmonary microvascular endothelium, allowing for the successful delivery of stabilized enhanced green fluorescent protein (eGFP) expressing messenger ribonucleic acid (mRNA). It is further shown, quantitatively, that positive surface charge is the main mechanism behind such high targeting efficiency for these polyplexes. Live in vivo imaging, flow cytometry of single cell suspensions, and confocal microscopy are used to demonstrate that positive polyplexes are enriched in the lung tissue and disseminated in 85-90% of the alveolar capillary endothelium, whilst being sparse in large vessels. Charge modification, achieved through poly(acrylic acid) or heparin coating, drives a highly significant reduction in both targeting percentage and targeting strength, highlighting the importance of specific surface charge, derived from chemical formulation, for efficient targeting of the pulmonary microvascular endothelium.


Assuntos
Endotélio Vascular/química , Nanopartículas/química , Polietilenoimina/química , Animais , Cátions/química , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Proteínas de Fluorescência Verde/genética , Ácido Linoleico/química , Pulmão/citologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Nanopartículas/metabolismo , Imagem Óptica , Polietilenoglicóis/química , Distribuição Tecidual
11.
ACS Appl Mater Interfaces ; 10(49): 41986-41998, 2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30426746

RESUMO

A critical issue in nanomedicine is on the understanding of nano-bio interface behaviors, particularly when the nanoparticles are inevitably decorated by protein coronas in the physiological fluids. In this study, the effects of particle surface corona on cancer cell targeting were investigated in simulated physiological fluids. Cell targeting was achieved by two strategies: (1) using conventional epithelial cell adhesion molecule antibody-functionalized Fe3O4 nanoparticles and (2) rendering the same but naked magnetic nanoparticles electrically positively charged, enabling them to electrostatically bind onto the negatively charged cancer cells. The cell-particle electrostatic binding was found to be much stronger with faster reaction kinetics than the immunological interactions even at 4 nC. Both types of nanoparticles were decorated with various protein coronas by administration in a simulated physiological system. Well-decorated by protein coronas, the electrically charged particles retained strong electrostatic interactions with cancer cells, even upon reversal of the particle zeta potential from positive to negative. This behavior was explained by a nonuniform corona modulation of the particle surface charge distributions, exposing locally positively charged regions, capable of strong electrostatic cell binding and magnetic capturing in a physiological environment. This fundamental discovery paves new way for sensitive detection of circulating tumor cells in whole blood in clinical settings.


Assuntos
Nanopartículas de Magnetita/química , Neoplasias/metabolismo , Coroa de Proteína/química , Células HeLa , Humanos , Células MCF-7 , Nanomedicina , Neoplasias/patologia , Eletricidade Estática
12.
Chem Commun (Camb) ; 54(82): 11622-11625, 2018 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-30264081

RESUMO

mp-MXene/TiO2-x nanodots (NDs) structurally composed of microporous MXene monolayers embedded with Ti3+-doped TiO2 nanodots were developed for the first time. The drastically enhanced catalytic efficiency (as much as 13 times higher than that of P25) in degrading dye molecules over mp-MXene/TiO2-x NDs is due to a synergistic effect of the pseudo-Fenton reaction and photocatalysis.

13.
Int J Pharm ; 548(1): 297-304, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-29981895

RESUMO

Poor aqueous solubility, chemical instability, and indiscriminate cytotoxicity have limited clinical development of camptothecin (CPT) as potent anticancer therapeutic. This research aimed at fabricating thermoresponsive nanocomposites that enhance solubility and stability of CPT in aqueous milieu and enable stimulus-induced drug release using magnetic hyperthermia. 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and l-α-dipalmitoylphosphatidyl glycerol (DPPG) (1:1, mol/mol) were immobilized on the surface of superparamagnetic Fe3O4 nanoparticles (SPIONs) via high affinity avidin-biotin interactions. Heating behavior was assessed using the MFG-1000 magnetic field generator. Encapsulation efficiency and drug release were quantified by fluorescence spectroscopy. Anticancer efficacy of medicated nanoparticles was measured in vitro using Jurkat cells. The results revealed that drug incorporation did not significantly alter particle size, zeta potential, magnetization, and heating properties of lipid-coated SPIONs. Drug loading efficiency was 93.2 ±â€¯5.1%. Drug release from medicated nanoparticles was significantly faster at temperatures above the lipid transition temperature, reaching 37.8 ±â€¯2.6% of incorporated payload after 12 min under therapeutically relevant hyperthermia (i.e., 42 °C). Medicated SPIONs induced greater cytotoxicity than CPT in solution suggesting synergistic activity of magnetically-induced hyperthermia and drug-induced apoptosis. These results underline the opportunity for thermoresponsive phospholipid-coated SPIONs to enable clinical development of highly lipophilic and chemically unstable drugs such as CPT for stimulus-induced cancer treatment.


Assuntos
Hipertermia Induzida , Nanopartículas de Magnetita/administração & dosagem , 1,2-Dipalmitoilfosfatidilcolina/administração & dosagem , 1,2-Dipalmitoilfosfatidilcolina/análogos & derivados , 1,2-Dipalmitoilfosfatidilcolina/química , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Humanos , Células Jurkat , Nanopartículas de Magnetita/química , Neoplasias/terapia , Fosfatidilgliceróis/administração & dosagem , Fosfatidilgliceróis/química
14.
Adv Sci (Weinh) ; 5(6): 1700805, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29938166

RESUMO

Although there have been more than 100 clinical trials, CpG-based immunotherapy has been seriously hindered by complications in the immunosuppressive microenvironment of established tumors. Inspired by the decisive role of fever upon systemic immunity, a photothermal CpG nanotherapeutics (PCN) method with the capability to induce an immunofavorable tumor microenvironment by casting a fever-relevant heat (43 °C) in the tumor region is developed. High-throughput gene profile analysis identifies nine differentially expressed genes that are closely immune-related upon mild heat, accompanied by IL-6 upregulation, a pyrogenic cytokine usually found during fever. When treated with intratumor PCN injection enabling mild heating in the tumor region, the 4T1 tumor-bearing mice exhibit significantly improved antitumor immune effects compared with the control group. Superb efficacy is evident from pronounced apoptotic cell death, activated innate immune cells, enhanced tumor perfusion, and intensified innate and adaptive immune responses. This work highlights the crucial role of mild heat in modulating the microenvironment in optimum for improved immunotherapy, by converting the tumor into an in situ vaccine.

15.
ACS Nano ; 12(7): 6398-6409, 2018 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-29927574

RESUMO

One of the major challenges in vaccine design has been the over dependence on incorporation of abundant adjuvants, which in fact is in violation of the "minimalist" principle. In the present study, a compact nanovaccine derived from a near whole antigen (up to 97 wt %) was developed. The nanovaccine structure was stabilized by free cysteines within each antigen (ovalbumin, OVA), which were tempospatially exposed and heat-driven to form an extensive intermolecular disulfide network. This process enables the engineering of a nanovaccine upon integration of the danger signal (CpG-SH) into the network during the synthetic process. The 50 nm-sized nanovaccine was developed comprising approximately 500 antigen molecules per nanoparticle. The nanovaccine prophylactically protected 70% of mice from tumorigenesis (0% for the control group) in murine B16-OVA melanoma. Significant tumor inhibition was achieved by strongly nanovaccine-induced cytotoxic T lymphocytes. This strategy can be adapted for the future design of vaccine for a minimalist composition in clinical settings.


Assuntos
Antígenos/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Melanoma Experimental/prevenção & controle , Nanopartículas/uso terapêutico , Ovalbumina/uso terapêutico , Animais , Antígenos/química , Vacinas Anticâncer/química , Ilhas de CpG , Cisteína/química , Temperatura Alta , Imunoterapia/métodos , Ativação Linfocitária , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Ovalbumina/química
16.
Adv Mater ; 30(17): e1705660, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29504159

RESUMO

Medical science has recently advanced to the point where diagnosis and therapeutics can be carried out with high precision, even at the molecular level. A new field of "precision medicine" has consequently emerged with specific clinical implications and challenges that can be well-addressed by newly developed nanomaterials. Here, a nanoscience approach to precision medicine is provided, with a focus on cancer therapy, based on a new concept of "molecularly-defined cancers." "Next-generation sequencing" is introduced to identify the oncogene that is responsible for a class of cancers. This new approach is fundamentally different from all conventional cancer therapies that rely on diagnosis of the anatomic origins where the tumors are found. To treat cancers at molecular level, a recently developed "microRNA replacement therapy" is applied, utilizing nanocarriers, in order to regulate the driver oncogene, which is the core of cancer precision therapeutics. Furthermore, the outcome of the nanomediated oncogenic regulation has to be accurately assessed by the genetically characterized, patient-derived xenograft models. Cancer therapy in this fashion is a quintessential example of precision medicine, presenting many challenges to the materials communities with new issues in structural design, surface functionalization, gene/drug storage and delivery, cell targeting, and medical imaging.


Assuntos
Medicina de Precisão , Animais , Modelos Animais de Doenças , Humanos , MicroRNAs , Nanoestruturas , Neoplasias
17.
J Biomed Mater Res B Appl Biomater ; 106(1): 88-95, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27875036

RESUMO

Biodegradable polymer poly (dl-lactide) (PDLLA) has been used as drug coating material for drug-eluting stents due to its excellent biocompatibility and sustained drug release ability. However, the uniform thin layer drug eluting coating on a stent not only inhibits the blood vessel's smooth muscle cell overgrowth but also delay the endotheliation process which is often associated with the occurrence of acute thrombosis. Therefore, in this study, we developed a novel coating method using PDLLA nanoparticles (NPs) as a coating to overcome this issue. The average 300 nm sized sirolimus-loaded PDLLA nanoparticles were prepared by a conventional emulsion solvent evaporation method. A low temperature plasma polymerization technology to graft hydrophilic polymers on to poly (l-lactide) stent was used to increase the surface coating efficiency of nanoparticles on the stent. Results showed that sirolimus-loaded nanoparticles can be successfully coated on to the stents with sustained drug release properties. In vitro cell culture study showed the drug loaded nanoparticle coating effectively inhibited the proliferation of smooth muscle cells while still allowed a faster proliferation of endothelial cells, suggesting that the new NP coated bioresorbable stents have the potential to reduce both the occurrence of in-stent restenosis and acute thrombosis. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 88-95, 2018.


Assuntos
Implantes Absorvíveis , Materiais Revestidos Biocompatíveis/química , Células Endoteliais/metabolismo , Oclusão de Enxerto Vascular/prevenção & controle , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Nanopartículas/química , Poliésteres/química , Stents , Prótese Vascular , Células Cultivadas , Preparações de Ação Retardada , Humanos
18.
Nanomedicine ; 14(2): 619-631, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29269324

RESUMO

Myocardial infarction (MI), known to be rapidly progressed and fatal, necessitates a timely and effective intervention particularly within golden 24 h. The crux is to develop a therapeutic agent that can early target the infarct site with integrated therapeutic capacity. Finding the AT1 receptor being most over-expressed at 24 h after MI, we developed a nanovector (AT1-PEG-DGL) anchored with AT1 targeting peptide, and simultaneously armed it with specific microRNA-1 inhibitor (AMO-1) to attenuate cardiomyocyte apoptosis. In vivo imaging after IV administration demonstrated that AT1-PEG-DGL quickly accumulated in the MI heart during the desired early period, significantly outperforming the control group without AT1 targeting. Most importantly, a pronounced in-vivo anti-apoptosis effect was observed upon a single IV injection. Apoptotic cell death in the infarct border zone was significantly decreased and the myocardial infarct size was reduced by 64.1% as compared with that in MI control group, promising for early MI treatment.


Assuntos
Dendrímeros/química , Terapia Genética , MicroRNAs/antagonistas & inibidores , Infarto do Miocárdio/terapia , Nanopartículas/administração & dosagem , Receptor Tipo 1 de Angiotensina/química , Animais , Apoptose , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Nanopartículas/química , Receptor Tipo 1 de Angiotensina/genética
19.
Mater Sci Eng C Mater Biol Appl ; 80: 88-92, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28866229

RESUMO

Dual surfaced dumbbell-like gold magnetic nanoparticles (Au-Fe3O4) were synthesized for targeted aptamers delivery. Their unique biological properties were characterized as a smart photo-controlled drug carrier. DNA aptamers targeting vascular endothelial growth factor (VEGF) were assembled onto the surface of Au-Fe3O4 by electrostatic absorption. The binding capacity of the nanoparticles with VEGF aptamers was confirmed by gel electrophoresis. The targeted recognization of ovarian cancer cells by the aptamers-functionalized Au-Fe3O4 nanoparticles (Apt-Au-Fe3O4 NPs) was observed by confocal microscopy. Apt-Au-Fe3O4 was found to bind with SKOV-3 ovarian cancer cells specifically, leading to marked intracellular release of aptamers upon plasmon-resonant light (605nm) radiation, and to enhance the in vitro inhibition against tumor cell proliferation. The results show high potential of Apt-Au-Fe3O4as a targeted cancer hyperthermia carrier by remote control with high spatial/temporal resolution.


Assuntos
Nanopartículas de Magnetita , Aptâmeros de Nucleotídeos , Ouro , Humanos , Magnetismo , Neoplasias , Fator A de Crescimento do Endotélio Vascular
20.
ACS Appl Mater Interfaces ; 9(26): 21820-21828, 2017 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-28573853

RESUMO

We report reduced graphene oxide (rGO)/single-walled carbon nanotube (SWCNT) hybrid aerogels with enhanced thermoelectric (TE) performance and removal of organic solvents by designing 3D double-interconnected network porous microstructures. A convenient, cost-effective, and scalable preparation procedure is proposed compared with conventional high-temperature pyrolysis and supercritical drying techniques. The obtained hybrid aerogels are systematically characterized by apparent density, scanning electron microscopy, X-ray photoemission spectroscopy, Raman spectroscopy, and porosity. An enhanced TE performance of ZT ≈ ∼8.03 × 10-3 has been achieved due to the 3D double-interconnected network porous microstructure, the energy-filtering effect, and the phonon scattering at the abundant interfaces and joints. In addition, upon a large axial compression deformation, a high degree of retention of the Seebeck coefficient and a simultaneously significant enhancement of the electrical conductivity are observed. Finally, the hybrid aerogels display high capability for the removal of diverse organic solvents and good recyclability. These findings open a new avenue for exploiting aerogels with multifunctions and widening the applications of TE materials by judicious microstructure design.

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