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1.
Adv Exp Med Biol ; 1177: 101-131, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32246445

RESUMO

Thrombosis, the localized clotting of blood that affects arterial or venous circulation, is one of the leading causes of death worldwide. Arterial thrombosis is commonly initiated by vascular endothelial injury, while venous thrombosis mainly stems from blood stasis. Despite these differences, platelet adhesion, activation and aggregation, and fibrin formation as a result of coagulation constitute the fundamental processes of thrombus formation. Antithrombotic drugs permitted on the clinical currently can dramatically reduce major adverse cardiovascular events; however, they can also increase the bleeding risk. Discovery of antithrombotic drugs that can effectively prevent thrombosis while sparing bleeding side effects remains unmet medical need. In this chapter, we provide an overview on the pathophysiology of thrombosis, followed by introduction of each class of antithrombotic drugs including their pharmacology, clinical applications and limitations. Practical challenges and future perspectives of antithrombotic drugs are discussed in the last part of this chapter.


Assuntos
Fibrinolíticos/farmacologia , Trombose/prevenção & controle , Coagulação Sanguínea/efeitos dos fármacos , Hemorragia/induzido quimicamente , Humanos , Adesividade Plaquetária/efeitos dos fármacos
2.
Mater Sci Eng C Mater Biol Appl ; 107: 110311, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761197

RESUMO

In this study, a small-diameter, double-layered eggshell membrane/thermoplastic polyurethane (ESM/TPU) vascular graft with a wavy structure was developed. The avian eggshell membrane, a fibrous structure similar to the extracellular matrix (ECM), has the potential to yield rapid endothelialization in vitro. The dopamine and heparin modification of the ESM surface not only promoted human umbilical vein endothelial cell (HUVEC) proliferation via cytocompatibility assessment, but also improved its anticoagulation properties as verified in platelet adhesion tests. The biomimetic mechanical properties of the vascular graft were provided by the elastic TPU fibers via electrospinning using a wavy cross-section rotating collector. The advantage of combining these two materials is to make use of the bioactivity of ESM as the internal membrane and the tunable mechanical properties of TPU as the external layer. The circumferentially wavy structure of the vascular graft produced a toe region in the non-linear section of the stress-strain curve similar to that of natural blood vessels. The ESM/TPU graft's circumferential ultimate strength was 2.57 MPa, its strain was 339% mm/mm, and its toe region was found to be around 20% mm/mm. Cyclical tension tests showed that the vascular graft could maintain good mechanical properties and showed no structural damage under repeated extension tests.


Assuntos
Materiais Biocompatíveis/química , Prótese Vascular , Casca de Ovo/química , Poliuretanos/química , Animais , Antitrombinas , Galinhas , Desenho de Equipamento , Matriz Extracelular/química , Células Endoteliais da Veia Umbilical Humana , Humanos , Tamanho da Partícula , Adesividade Plaquetária/efeitos dos fármacos
3.
ACS Appl Mater Interfaces ; 11(38): 34652-34662, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31483604

RESUMO

Modern crises in implantable or indwelling blood-contacting medical devices are mainly due to the dual problems of infection and thrombogenicity. There is a paucity of biomaterials that can address both problems simultaneously through a singular platform. Taking cues from the body's own defense mechanism against infection and blood clotting (thrombosis) via the endogenous gasotransmitter nitric oxide (NO), both of these issues are addressed through the development of a layered S-nitroso-N-acetylpenicillamine (SNAP)-doped polymer with a blended selenium (Se)-polymer interface. The unique capability of the SNAP-Se-1 polymer composites to explicitly release NO from the SNAP reservoir as well as generate NO via the incorporated Se is reported for the first time. The NO release from the SNAP-doped polymer increased substantially in the presence of the Se interface. The Se interface was able to generate NO in the presence of S-nitrosoglutathione (GSNO) and glutathione (GSH), demonstrating the capability of generating NO from endogenous S-nitrosothiols (RSNO). Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) traced distribution of elemental Se nanoparticles on the interface and the surface properties were evaluated by surface wettability and roughness. The SNAP-Se-1 efficiently inhibited the growth of bacteria and reduced platelet adhesion while showing minimal cytotoxicity, thus potentially eliminating the risks of systemic antibiotic and blood coagulation therapy. The SNAP-Se-1 exhibited antibacterial activity of ∼2.39 and ∼2.25 log reductions in the growth of clinically challenging adhered Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. SNAP-Se-1 also significantly reduced platelet adhesion by 85.5% compared to corresponding controls. A WST-8-based cell viability test performed on NIH 3T3 mouse fibroblast cells provided supporting evidence for the potential biocompatibility of the material in vitro. These results highlight the prospective utility of SNAP-Se-1 as a blood-contacting infection-resistant biomaterial in vitro which can be further tuned by application specificity.


Assuntos
Escherichia coli/crescimento & desenvolvimento , Polímeros , S-Nitroso-N-Acetilpenicilamina , Selênio , Staphylococcus aureus/crescimento & desenvolvimento , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Células NIH 3T3 , Nanopartículas , Óxido Nítrico/farmacocinética , Óxido Nítrico/farmacologia , Adesividade Plaquetária/efeitos dos fármacos , Polímeros/química , Polímeros/farmacocinética , Polímeros/farmacologia , S-Nitroso-N-Acetilpenicilamina/química , S-Nitroso-N-Acetilpenicilamina/farmacocinética , S-Nitroso-N-Acetilpenicilamina/farmacologia , Selênio/química , Selênio/farmacocinética , Selênio/farmacologia , Suínos
4.
Mater Sci Eng C Mater Biol Appl ; 104: 109947, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499970

RESUMO

Due to its good biodegradability and mechanical properties, magnesium alloys are considered as the ideal candidate for the cardiovascular stents. However, the rapid degradation in human physiological environment and the poor biocompatibility seriously limit its application for biomaterials. In the present study, a chitosan/heparinized graphene oxide (Chi/HGO) multilayer coating was constructed on the AZ31B magnesium alloy surface using layer-by-layer (LBL) method to improve the corrosion resistance and biocompatibility. The results of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectrum (RAMAN), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) showed that a dense and compact Chi/HGO multilayer coating was fabricated on the magnesium alloy surface. The results of potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), pH value changes and magnesium ion release suggested that the multilayer coating can significantly enhance the corrosion resistance of the magnesium alloy. Moreover, the Chi/HGO multilayer coating could not only significantly reduce the hemolysis rate and platelet adhesion, but also promote the adhesion and proliferation of endothelial cells. Therefore, the Chi/HGO multilayer coating can simultaneously improve the corrosion resistance and biocompatibility of the magnesium alloys.


Assuntos
Quitosana/química , Materiais Revestidos Biocompatíveis/química , Grafite/química , Heparina/química , Magnésio/química , Ligas/química , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Corrosão , Células Endoteliais/efeitos dos fármacos , Humanos , Teste de Materiais/métodos , Microscopia Eletrônica de Varredura/métodos , Adesividade Plaquetária/efeitos dos fármacos , Espectrometria por Raios X/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Propriedades de Superfície/efeitos dos fármacos
5.
Mater Sci Eng C Mater Biol Appl ; 104: 109952, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499985

RESUMO

The aim of this work is to provide a new kind of polyurethane with improved surface blood compatibility for long-term blood-contacting biomaterials. In the study, an aliphatic poly(ester-urethane) (H-PEU) with uniform-size hard segments was synthesized by one-step chain extension of poly(ε-caprolactone) (PCL) with diurethane diisocyanate (HBH), and biomimetic phosphorylcholine (PC) groups were immobilized onto the film surface with high grafting efficiency by three-step chemical treatments under mild reaction conditions. The H-PEU film was firstly treated with 1,6-hexanediisocyanate (HDI) to introduce -NCO groups on the surface (H-PEU-NCO) through an allophanate reaction; the -NCO groups were then coupled via a condensation reaction with one of -NH2 groups of tris(2-aminoethyl)amine (TAEA) to immobilize -NH2 on the surface (H-PEU-NH2); finally, the double bond of 2-methacryloyloxyethyl phosphorylcholine (MPC) reacted with -NH2 by Michael addition reaction to obtain MPC-grafted H-PEU (H-PEU-MPC). The modified surfaces were characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The results verified that MPC was successfully grafted onto H-PEU surface with high grafting density. The blank and modified films showed similar crystallization behaviors, thermal stabilities and mechanical properties, indicating that the chemical treatments had minimum influence on the physicochemical properties of the substrate. The H-PEU-MPC displaying a much lower water contact angle (~15.2°) than H-PEU (80.3°) meant that the hydrophilic PC functional groups improved the surface hydrophilicity significantly. The surface blood compatibility was examined by bovine serum albumin adsorption and platelet adhesion tests, and the results revealed that H-PEU-MPC had improved resistance to protein adsorption and platelet adhesion capacity. The MPC-grafted H-PEU film possessed outstanding mechanical properties (ultimate stress: 36.1 MPa; strain at break: 883%), low protein adsorption quantity (1.33 µg/cm2) and good anti-platelet adhesion capacity (582 ±â€¯16 per mm2), implying its high potential to be applied as biomaterials for vascular grafts, subcutaneously implanted devices or other blood-contacting devices.


Assuntos
Materiais Biocompatíveis/química , Metacrilatos/química , Fosforilcolina/análogos & derivados , Poliésteres/química , Poliuretanos/química , Adsorção/efeitos dos fármacos , Animais , Caproatos/química , Isocianatos/química , Lactonas/química , Fosforilcolina/química , Adesividade Plaquetária/efeitos dos fármacos , Coelhos , Soroalbumina Bovina/química , Propriedades de Superfície
6.
Biomater Sci ; 7(9): 3741-3750, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31389408

RESUMO

Developing a facile and versatile strategy to endow blood-contacting devices with surface in situ nitric oxide (NO) generation properties by catalytically decomposing endogenously existing S-nitrosothiols (RSNO) from blood is of immense scientific and engineering interest. However, most available strategies involve drawbacks of low efficiency, complex processes, and toxic chemicals. In this work, we report a facile method to deposit a NO-generating coating on a 316L stainless steel (SS) substrate through dopamine-mediated one-step assembly of CuII-dopamine (CuII-DA) coordination complexes. The chelation of CuII in the CuII-DA network endowed the coating with high in situ NO catalytic capacity by decomposing RSNO endogenously existing in blood. Of special importance is that this dopamine-mediated method possesses the merits of a simple preparation process, friendliness to the environment, high controllability of the CuII-DA surface chemistry, highly effective surface coating formation, and long-term and durable catalytic activity of NO. The continuous release of NO from the CuII-DA-coated 316L SS impressively improved its antithrombogenicity and selectively enhanced endothelial cell (EC) growth while inhibiting smooth muscle cell (SMC) proliferation.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Cobre/farmacologia , Dopamina/farmacologia , Óxido Nítrico/biossíntese , Catálise , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Cobre/química , Dopamina/química , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Estrutura Molecular , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Óxido Nítrico/sangue , Adesividade Plaquetária/efeitos dos fármacos
7.
Int J Nanomedicine ; 14: 4817-4831, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308660

RESUMO

Background: In vitro (1R,3S)-1-methyl-1,2,3,4-tetrahydro-ß-carboline-3-carboxyl-Lys(Pro-Ala-Lys)-Arg-Gly-Asp-Val (MTCA-KKV) adheres activated platelets, targets P-selectin and GPIIb/IIIa. This led to the development of MTCA-KKV as thrombus targeting nano-medicine. Methods: MTCA-KKV was characterized by nano-feature, anti-thrombotic activity, thrombolytic activity, thrombus target and targeting release. Results: In vivo 0.01 µmol/kg of MTCA-KKV formed nano-particles less than 100 nm in diameter, targeted thrombus, released anti-thrombotic and thrombolytic pharmacophores, prevented thrombosis and dissolved blood clots. Conclusion: Based on the profiles of targeting thrombus, targeting release, inhibiting thrombosis and dissolving blood clots MTCA-KKV is a promising nano-medicine.


Assuntos
Coagulação Sanguínea , Carbolinas/química , Carbolinas/uso terapêutico , Nanopartículas/química , Peptídeos/uso terapêutico , Trombose/sangue , Trombose/tratamento farmacológico , Administração Oral , Animais , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Carbolinas/administração & dosagem , Eritrócitos/efeitos dos fármacos , Humanos , Leucócitos/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Masculino , Nanopartículas/ultraestrutura , Selectina-P/metabolismo , Peptídeos/farmacologia , Adesividade Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Ratos Sprague-Dawley , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Biomater Sci ; 7(9): 3795-3800, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31233048

RESUMO

In this work, a charge conversion mechanism was introduced to build a bacteria responsive antibacterial surface. The antimicrobial surface is constructed by immobilizing pH-responsive moieties on the surface of the material, followed by immobilization of the antimicrobial peptide (AMP) melittin (MLT) by strong electrostatic interaction. The constructed surface exhibited self-defensive properties against Gram-positive and Gram-negative bacteria. In comparison with previously reported self-defensive systems with side effects of drug resistance, this antibacterial surface prevented the undesirable drug resistance. The bactericidal mechanism of the antibacterial surface is involved in a lytic cell membrane. Once bacteria come into contact with the surface, the bactericidal properties will be triggered on the surface. As bacteria exponentially grow, they accumulate and attach to the surface, which will develop a slightly acidic micro-environment and subsequently activate the pH responsive surface to release MLT to kill bacteria. This study broadened our understanding of the development of antibacterial surfaces and provided new insights for the antibacterial surface to be utilized in industrial, biological and medical applications.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/química , Sobrevivência Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Adesividade Plaquetária/efeitos dos fármacos , Propriedades de Superfície
9.
Biomater Sci ; 7(7): 2907-2919, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31089612

RESUMO

Although the design of more biocompatible polymeric implants has been studied for decades, their intended functionality continues to be impaired by the response of the host tissue to foreign bodies at the tissue-implant interface. In particular, the formation and contracture of fibrous capsules prevent the intimate integration of an implant with surrounding tissues, which leads to structural deformation of the implants and persistent discomfort and pain. We report a new surface nano-engineered silicone implant that reduces fibrous capsule formation and improves the biocompatibility of it via sputtering-based plasma immersion ion implantation (S-PIII). This technique can introduce biologically compatible tantalum (Ta) on the silicone surface to produce a Ta-implanted skin layer (<60 nm thick) as well as generate either smooth (Smooth/Ta silicone) or nano-textured (Nano/Ta silicone) surface morphologies. The biologically inert chemical structure and strong hydrophobic surface characteristics of bare silicone are substantially ameliorated after Ta ion implantation. In particular, the Nano/Ta silicone implant's combination of surface nano-texturing as a physical cue and the Ta-implanted layer as a chemical cue was found to be very effective at achieving outstanding hydrophilicity and fibroblast affinity compared to the bare and Smooth/Ta silicone implants. In a mouse in vivo study conducted for 8 weeks, the Nano/Ta silicone implant inhibited fibrous capsule formation and contracture on its surface better than the bare silicone based on an analysis of the number of macrophages, myofibroblast differentiation and activation, collagen density, and thickness of fibrous capsules.


Assuntos
Engenharia , Nanotecnologia , Próteses e Implantes , Silicones/química , Tantálio/química , Animais , Fibroblastos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Fenômenos Mecânicos , Ativação Plaquetária/efeitos dos fármacos , Adesividade Plaquetária/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Silicones/farmacologia , Propriedades de Superfície
10.
Int J Biol Macromol ; 134: 435-444, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31100389

RESUMO

Starch hemostatic agents have been clinically used in surgical hemostasis in recent years. Calcium ion (Ca2+)-exchange cross-linked porous starch microparticles (Ca2+CPSMs) were prepared as a new hemostatic agent to enhance the hemostatic efficacy. A series of Ca2+CPSMs with varying Ca2+ contents were prepared and characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscope (SEM), and ion content analysis. The XPS and FT-IR results indicated that the surface of Ca2+CPSMs was modified by Ca2+, which might form coordination bonds with oxygen atoms of starch molecules. Ca2+CPSMs revealed a porous surface structure and a lower crystallinity degree according to SEM and XRD, which facilitated the phosphate buffer saline (PBS) uptake rate and enzymatic degradation in vitro. The fast release of Ca2+ from Ca2+CPSMs accelerated the whole blood clotting rate, shortened the activated partial thromboplastin time, and promoted platelet adhesion. The physical hemostatic mechanism benefited from the rapid PBS uptake capacity and porous surface structure of Ca2+CPSMs, in addition to the chemical activation of coagulation process by Ca2+, thus achieving a significant hemorrhage control in the mouse tail amputation model.


Assuntos
Cálcio/química , Hemostáticos/química , Hemostáticos/farmacologia , Troca Iônica , Íons/química , Amido/química , Animais , Coagulação Sanguínea/efeitos dos fármacos , Fenômenos Químicos , Hemostasia/efeitos dos fármacos , Cinética , Camundongos , Adesividade Plaquetária/efeitos dos fármacos , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/ultraestrutura , Difração de Raios X
11.
J Mater Sci Mater Med ; 30(4): 44, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30929088

RESUMO

Hydroxyapatite is an ideal biomaterial for bone tissue engineering due to its biocompatibility and hemocompatibility which have been widely studied by many researchers. The incorporation of nanoporosity into hydroxyapatite could transform the biomaterial into an effective adsorbent for uremic toxins removal especially in artificial kidney system. However, the effect of nanoporosity incorporation on the hemocompatibility of hydroxyapatite has yet to be answered. In this study, nanoporous hydroxyapatite was synthesized using hydrothermal technique and its hemocompatibility was determined. Non-ionic surfactants were used as soft templates to create porosity in the hydroxyapatite. The presence of pure hydroxyapatite phase in the synthesized samples is validated by X-ray diffraction analysis and Fourier transform infrared spectroscopy. The TEM images show that the hydroxyapatite formed rod-like particles with the length of 21-90 nm and diameter of 11-70 nm. The hydroxyapatite samples exhibit BET surface area of 33-45 m2 g-1 and pore volume of 0.35-0.44 cm3 g-1. The hemocompatibility of the hydroxyapatite was determined via hemolysis test, platelet adhesion, platelet activation and blood clotting time measurement. The nanoporous hydroxyapatite shows less than 5% hemolysis, suggesting that the sample is highly hemocompatible. There is no activation and morphological change observed on the platelets adhered onto the hydroxyapatite. The blood clotting time demonstrates that the blood incubated with the hydroxyapatite did not coagulate. This study summarizes that the synthesized nanoporous hydroxyapatite is a highly hemocompatible biomaterial and could potentially be utilized in biomedical applications.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Durapatita/química , Durapatita/farmacologia , Hemólise/efeitos dos fármacos , Nanoporos , Plaquetas/fisiologia , Fenômenos Químicos , Humanos , Teste de Materiais , Nanoporos/ultraestrutura , Ativação Plaquetária/efeitos dos fármacos , Adesividade Plaquetária/efeitos dos fármacos , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Propriedades de Superfície , Difração de Raios X
12.
Mol Ther ; 27(7): 1228-1241, 2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-30987839

RESUMO

Endothelial surface and circulating glycoprotein von Willebrand factor (vWF) regulates platelet adhesion and is associated with thrombotic diseases, including ischemic stroke, myocardial infarction, and peripheral vascular disease. Thrombosis, as manifested in these diseases, is the leading cause of disability and death in the western world. Current parenteral antithrombotic and thrombolytic agents used to treat these conditions are limited by a short therapeutic window, irreversibility, and major risk of hemorrhage. To overcome these limitations, we developed a novel anti-vWF aptamer, called DTRI-031, that selectively binds and inhibits vWF-mediated platelet adhesion and arterial thrombosis while enabling rapid reversal of this antiplatelet activity by an antidote oligonucleotide (AO). Aptamer DTRI-031 exerts dose-dependent inhibition of platelet aggregation and thrombosis in whole blood and mice, respectively. Moreover, DTRI-031 can achieve potent vascular recanalization of platelet-rich thrombotic occlusions in murine and canine carotid arteries. Finally, DTRI-031 activity is rapidly (<5 min) and completely reversed by AO administration in a murine saphenous vein hemorrhage model, and murine toxicology studies indicate the aptamer is well tolerated. These findings suggest that targeting vWF with an antidote-controllable aptamer potentially represents an effective and safer treatment for thrombosis patients having platelet-rich arterial occlusions in the brain, heart, or periphery.


Assuntos
Aptâmeros de Nucleotídeos/farmacologia , Arteriopatias Oclusivas/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos/métodos , Fibrinolíticos/farmacologia , Trombose/tratamento farmacológico , Trombose/prevenção & controle , Fator de von Willebrand/antagonistas & inibidores , Animais , Antídotos/farmacologia , Aptâmeros de Nucleotídeos/síntese química , Aptâmeros de Nucleotídeos/metabolismo , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Lesões das Artérias Carótidas/tratamento farmacológico , Cães , Relação Dose-Resposta a Droga , Feminino , Voluntários Saudáveis , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oligonucleotídeos/farmacologia , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Fator de von Willebrand/metabolismo
13.
Colloids Surf B Biointerfaces ; 179: 405-413, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30999119

RESUMO

The surface characteristics of coronary stents play a pivotal role in inhibiting in-stent restenosis and late-stent thrombosis. In this study, a sol-gel-derived silica xerogel-chitosan hybrid coating was applied to Co-Cr stent and was reported, for the first time, as a biocompatible drug delivery tool in vascular stent application. A dense and uniform chitosan-silica xerogel hybrid coating (<1-µm thick) was applied on bare Co-Cr material. Sirolimus was well incorporated into the hybrid coatings without re-crystallization. The chitosan-silica hybrid coating with 30 wt% silica xerogel showed better mechanical stability and good adhesive strength without any cracking or delamination. The chitosan-silica hybrid coated Co-Cr surface exhibited significantly improved wettability and corrosion resistance compared to the chitosan coated Co-Cr surface. In addition, the hybrid coating layer enabled efficient loading of sirolimus, owing to the unique mesoporous structure of silica xerogel, which further allowed the sustained release of sirolimus over 3 weeks. In-vitro tests with human umbilical cord vein endothelial cells and blood platelets confirmed that the chitosan-silica hybrid coating had excellent cytocompatibility and hemocompatibilty. Thus, this study demonstrated that the chitosan-silica hybrid material is a promising material for coating coronary stents, with minimal risk of in-stent restenosis and thrombogenicity.


Assuntos
Materiais Revestidos Biocompatíveis/química , Stents Farmacológicos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Compostos Inorgânicos/química , Teste de Materiais , Compostos Orgânicos/química , Sirolimo/farmacologia , Quitosana/química , Humanos , Adesividade Plaquetária/efeitos dos fármacos , Dióxido de Silício/química , Molhabilidade
14.
Mar Drugs ; 17(4)2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022915

RESUMO

Medical device-associated infections are a major health threat, representing about half of all hospital-acquired infections. Current strategies to prevent this problem based on device coatings with antimicrobial compounds (antibiotics or antiseptics) have proven to be insufficient, often toxic, and even promoting bacterial resistance. Herein, we report the development of an infection-preventive coating (CyanoCoating) produced with an extracellular polymer released by the marine cyanobacterium Cyanothece sp. CCY 0110. CyanoCoating was prepared by spin-coating and its bacterial anti-adhesive efficiency was evaluated against relevant etiological agents (Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa and Escherichia coli) and platelets, both in the presence or absence of human plasma proteins. CyanoCoating cytotoxicity was assessed using the L929 fibroblasts cell line. CyanoCoating exhibited a smooth topography, low thickness and high hydrophilic properties with mild negative charge. The non-cytotoxic CyanoCoating prevented adhesion of all the bacteria tested (≤80%) and platelets (<87%), without inducing platelet activation (even in the presence of plasma proteins). The significant reduction in protein adsorption (<77%) confirmed its anti-adhesive properties. The development of this anti-adhesive coating is an important step towards the establishment of a new technological platform capable of preventing medical device-associated infections, without inducing thrombus formation in blood-contacting applications.


Assuntos
Anti-Infecciosos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biopolímeros/farmacologia , Cyanothece/química , Animais , Anti-Infecciosos/química , Biofilmes/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Matriz Extracelular de Substâncias Poliméricas/química , Humanos , Teste de Materiais , Camundongos , Ativação Plaquetária/efeitos dos fármacos , Adesividade Plaquetária/efeitos dos fármacos , Poliuretanos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacos
15.
Oxid Med Cell Longev ; 2019: 1050476, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31007831

RESUMO

The progression of Alzheimer's dementia is associated with neurovasculature impairment, which includes inflammation, microthromboses, and reduced cerebral blood flow. Here, we investigate the effects of ß amyloid peptides on the function of platelets, the cells driving haemostasis. Amyloid peptide ß1-42 (Aß1-42), Aß1-40, and Aß25-35 were tested in static adhesion experiments, and it was found that platelets preferentially adhere to Aß1-42 compared to other Aß peptides. In addition, significant platelet spreading was observed over Aß1-42, while Aß1-40, Aß25-35, and the scAß1-42 control did not seem to induce any platelet spreading, which suggested that only Aß1-42 activates platelet signalling in our experimental conditions. Aß1-42 also induced significant platelet adhesion and thrombus formation in whole blood under venous flow condition, while other Aß peptides did not. The molecular mechanism of Aß1-42 was investigated by flow cytometry, which revealed that this peptide induces a significant activation of integrin αIIbß3, but does not induce platelet degranulation (as measured by P-selectin membrane translocation). Finally, Aß1-42 treatment of human platelets led to detectable levels of protein kinase C (PKC) activation and tyrosine phosphorylation, which are hallmarks of platelet signalling. Interestingly, the NADPH oxidase (NOX) inhibitor VAS2870 completely abolished Aß1-42-dependent platelet adhesion in static conditions, thrombus formation in physiological flow conditions, integrin αIIbß3 activation, and tyrosine- and PKC-dependent platelet signalling. In summary, this study highlights the importance of NOXs in the activation of platelets in response to amyloid peptide ß1-42. The molecular mechanisms described in this manuscript may play an important role in the neurovascular impairment observed in Alzheimer's patients.


Assuntos
Peptídeos beta-Amiloides/toxicidade , NADPH Oxidases/metabolismo , Fragmentos de Peptídeos/toxicidade , Adesividade Plaquetária/efeitos dos fármacos , Trombose/patologia , Benzoxazóis/farmacologia , Humanos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Triazóis/farmacologia
16.
Mater Sci Eng C Mater Biol Appl ; 99: 1274-1288, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889662

RESUMO

Here we developed a semi-interpenetrating network (IPN) hydrogel obtained by free radical polymerization to fabricate a coated stent with the aim of incorporating a natural topography present in the human body to improve biological activity. The method involves sandwiching a bare metal stent in the semi-IPN hydrogel via solution cast molding. The bio-functionality of the membrane could be tuned by incorporating Polydopamine into the matrix, and also the mechanical property was optimized by choosing an adequate concentration of acrylamide. The coating containing polydopamine hydrogel showed good mechanical stability under continuous flow condition, as demonstrated by crimping and deployment into a catheter without damage. Stent polymer bonding was enhanced via polydopamine incorporation in the matrix. The non-thrombogenicity of the coating containing hydrogel was confirmed through dynamic hemocompatibility studies in vitro. Vascular simulations, including other biomechanical performance, like durability testing, radial strength, and recoil, were demonstrated. The dopamine containing hydrogel membrane (DCHM) was found to promote cell material interaction due to the ability of the catechol to bind protein and induce HUVECs cytoplasmic spreading, proliferation, and migration, with reduced smooth muscle cell (SMCs) activity. SMCs inhibition correlated well with the amount of incorporated catechol in the matrix. Our results show that this material used as coated stent could be more effective in suppressing platelet aggregation with improved haemocompatibility/biocompatibility for faster re-endothelialization than bare metal stent (BMS).


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Hidrogéis/farmacologia , Polímeros/farmacologia , Stents , Trombose/patologia , Adsorção , Artérias/fisiologia , Materiais Biomiméticos/química , Testes de Coagulação Sanguínea , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Simulação por Computador , Análise de Elementos Finitos , Hemodinâmica/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Indóis/farmacologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Adesividade Plaquetária/efeitos dos fármacos , Resistência à Tração
17.
Cells ; 8(2)2019 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-30754723

RESUMO

Typical Rho GTPases, such as Rac1, Cdc42, and RhoA, act as molecular switches regulating various aspects of platelet cytoskeleton reorganization. The loss of these enzymes results in reduced platelet functionality. Atypical Rho GTPases of the RhoBTB subfamily are characterized by divergent domain architecture. One family member, RhoBTB3, is expressed in platelets, but its function is unclear. In the present study we examined the role of RhoBTB3 in platelet function using a knockout mouse model. We found the platelet count, size, numbers of both alpha and dense granules, and surface receptor profile in these mice were comparable to wild-type mice. Deletion of Rhobtb3 had no effect on aggregation and dense granule secretion in response to a range of agonists including thrombin, collagen, and adenosine diphosphate (ADP). By contrast, alpha-granule secretion increased in mice lacking RhoBTB3 in response to thrombin, collagen related peptide (CRP) and U46619/ADP. Integrin activation and spreading on fibrinogen and collagen under static conditions were also unimpaired; however, we observed reduced platelet accrual on collagen under flow conditions. These defects did not translate into alterations in tail bleeding time. We conclude that genetic deletion of Rhobtb3 leads to subtle alterations in alpha-granule secretion and adhesion to collagen without significant effects on hemostasis in vivo.


Assuntos
Plaquetas/metabolismo , Colágeno/farmacologia , Grânulos Citoplasmáticos/metabolismo , Adesividade Plaquetária , Reologia , Proteínas rho de Ligação ao GTP/deficiência , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/ultraestrutura , Linhagem Celular , Grânulos Citoplasmáticos/efeitos dos fármacos , Humanos , Megacariócitos/efeitos dos fármacos , Megacariócitos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismo
18.
Blood ; 133(14): 1597-1606, 2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30692122

RESUMO

The third-generation tyrosine kinase inhibitor (TKI) ponatinib has been associated with high rates of acute ischemic events. The pathophysiology responsible for these events is unknown. We hypothesized that ponatinib produces an endothelial angiopathy involving excessive endothelial-associated von Willebrand factor (VWF) and secondary platelet adhesion. In wild-type mice and ApoE-/- mice on a Western diet, ultrasound molecular imaging of the thoracic aorta for VWF A1-domain and glycoprotein-Ibα was performed to quantify endothelial-associated VWF and platelet adhesion. After treatment of wild-type mice for 7 days, aortic molecular signal for endothelial-associated VWF and platelet adhesion were five- to sixfold higher in ponatinib vs sham therapy (P < .001), whereas dasatinib had no effect. In ApoE-/- mice, aortic VWF and platelet signals were two- to fourfold higher for ponatinib-treated compared with sham-treated mice (P < .05) and were significantly higher than in treated wild-type mice (P < .05). Platelet and VWF signals in ponatinib-treated mice were significantly reduced by N-acetylcysteine and completely eliminated by recombinant ADAMTS13. Ponatinib produced segmental left ventricular wall motion abnormalities in 33% of wild-type and 45% of ApoE-/- mice and corresponding patchy perfusion defects, yet coronary arteries were normal on angiography. Instead, a global microvascular angiopathy was detected by immunohistochemistry and by intravital microscopy observation of platelet aggregates and nets associated with endothelial cells and leukocytes. Our findings reveal a new form of vascular toxicity for the TKI ponatinib that involves VWF-mediated platelet adhesion and a secondary microvascular angiopathy that produces ischemic wall motion abnormalities. These processes can be mitigated by interventions known to reduce VWF multimer size.


Assuntos
Doenças Cardiovasculares/induzido quimicamente , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Imidazóis/toxicidade , Piridazinas/toxicidade , Microangiopatias Trombóticas/complicações , Animais , Aorta/metabolismo , Endotélio/metabolismo , Humanos , Isquemia/induzido quimicamente , Camundongos , Camundongos Knockout , Adesividade Plaquetária/efeitos dos fármacos , Inibidores de Proteínas Quinases/toxicidade , Disfunção Ventricular/induzido quimicamente , Fator de von Willebrand/efeitos dos fármacos , Fator de von Willebrand/metabolismo
19.
PLoS One ; 14(1): e0210337, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30689642

RESUMO

Therapeutic modulation of protein interactions is challenging, but short linear motifs (SLiMs) represent potential targets. Focal adhesions play a central role in adhesion by linking cells to the extracellular matrix. Integrins are central to this process, and many other intracellular proteins are components of the integrin adhesome. We applied a peptide network targeting approach to explore the intracellular modulation of integrin function in platelets. Firstly, we computed a platelet-relevant integrin adhesome, inferred via homology of known platelet proteins to adhesome components. We then computationally selected peptides from the set of platelet integrin adhesome cytoplasmic and membrane adjacent protein-protein interfaces. Motifs of interest in the intracellular component of the platelet integrin adhesome were identified using a predictor of SLiMs based on analysis of protein primary amino acid sequences (SLiMPred), a predictor of strongly conserved motifs within disordered protein regions (SLiMPrints), and information from the literature regarding protein interactions in the complex. We then synthesized peptides incorporating these motifs combined with cell penetrating factors (tat peptide and palmitylation for cytoplasmic and membrane proteins respectively). We tested for the platelet activating effects of the peptides, as well as their abilities to inhibit activation. Bioactivity testing revealed a number of peptides that modulated platelet function, including those derived from α-actinin (ACTN1) and syndecan (SDC4), binding to vinculin and syntenin respectively. Both chimeric peptide experiments and peptide combination experiments failed to identify strong effects, perhaps characterizing the adhesome as relatively robust against within-adhesome synergistic perturbation. We investigated in more detail peptides targeting vinculin. Combined experimental and computational evidence suggested a model in which the positively charged tat-derived cell penetrating part of the peptide contributes to bioactivity via stabilizing charge interactions with a region of the ACTN1 negatively charged surface. We conclude that some interactions in the integrin adhesome appear to be capable of modulation by short peptides, and may aid in the identification and characterization of target sites within the complex that may be useful for therapeutic modulation.


Assuntos
Adesões Focais/química , Adesões Focais/fisiologia , Integrinas/química , Integrinas/fisiologia , Peptídeos/química , Peptídeos/farmacologia , Motivos de Aminoácidos , Sequência de Aminoácidos , Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Adesões Focais/efeitos dos fármacos , Células HeLa , Humanos , Integrinas/genética , Modelos Moleculares , Peptídeos/genética , Ativação Plaquetária/efeitos dos fármacos , Ativação Plaquetária/fisiologia , Adesividade Plaquetária/efeitos dos fármacos , Adesividade Plaquetária/fisiologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Mapas de Interação de Proteínas , Vinculina/metabolismo
20.
Mater Sci Eng C Mater Biol Appl ; 96: 509-521, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30606560

RESUMO

Endothelial extracellular matrix (EC-ECM) modification by decellularization is generally recognized as an effective method for cardiovascular biomaterials to enhance their biocompatibility. However, the now available EC-ECM was mainly secreted by the in vitro cultured endothelial cells which lacked a physiological growth environment in vivo, such as blood flow shear stress (BFSS) acting, thus had a serious defect of biocompatibility. Our previous work markedly improved the biocompatibility of the EC-ECM modified materials by simulating the BFSS acting to control the endothelial cells with hyaluronic acid (HA) micro-pattern. In this contribution, the EC-ECM was further enriched onto the HA micro-pattern via a novel layer-by-layer decellularizatio method. In vitro platelets adhesion/activation, macrophages attachment test and ex vivo blood experiment of New Zealand White Rabbits suggested better blood compatibility and anti-inflammation property of this novel biomimetic ECM surface. The endothelial cells culture tests and in vivo rat subcutaneous implantation also proved its good pro-endothelialization function and tissue compatibility. In summary, the present study demonstrated better biocompatibility of the novel biomimetic ECM surface and its potential application for cardiovascular biomaterials modification.


Assuntos
Materiais Biomiméticos , Matriz Extracelular/química , Células Endoteliais da Veia Umbilical Humana/metabolismo , Teste de Materiais , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Plaquetas/citologia , Plaquetas/metabolismo , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/metabolismo , Adesividade Plaquetária/efeitos dos fármacos
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