Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Immunol ; 202(7): 2044-2056, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30760622

RESUMO

Deregulated immune response to a dysbiotic resident microflora within the oral cavity leads to chronic periodontal disease, local tissue destruction, and various systemic complications. To preserve tissue homeostasis, inflammatory signaling pathways involved in the progression of periodontitis must be tightly regulated. A20 (TNFAIP3), a ubiquitin-editing enzyme, has emerged as one of the key regulators of inflammation. Yet, the function of A20 in the oral mucosa and the biological pathways in which A20 mitigates periodontal inflammation remain elusive. Using a combination of in vivo and ex vivo disease models, we report in this study that A20 regulates inflammatory responses to a keystone oral bacterium, Porphyromonas gingivalis, and restrains periodontal inflammation through its effect on NF-κB signaling and cytokine production. Depletion of A20 using gene editing in human macrophage-like cells (THP-1) significantly increased cytokine secretion, whereas A20 overexpression using lentivirus infection dampened the cytokine production following bacterial challenge through modulating NF-κB activity. Similar to human cells, bone marrow-derived macrophages from A20-deficient mice infected with P. gingivalis displayed increased NF-κB activity and cytokine production compared with the cells isolated from A20-competent mice. Subsequent experiments using a murine ligature-induced periodontitis model showed that even a partial loss of A20 promotes an increased inflammatory phenotype and more severe bone loss, further verifying the critical function of A20 in the oral mucosa. Collectively, to our knowledge, these findings reveal the first systematic evidence of a physiological role for A20 in the maintenance of oral tissue homeostasis as a negative regulator of inflammation.


Assuntos
Inflamação/imunologia , Mucosa Bucal/imunologia , NF-kappa B/imunologia , Periodontite/imunologia , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/imunologia , Animais , Células HEK293 , Humanos , Imunidade nas Mucosas/imunologia , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mucosa Bucal/metabolismo , NF-kappa B/metabolismo , Periodontite/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo
2.
Clin Oral Implants Res ; 31(4): 374-387, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31953969

RESUMO

OBJECTIVES: This study determined whether implant surfaces that promote osseointegration in normal rats can promote osseointegration in osteoporotic rats without pharmacologic intervention. MATERIALS AND METHODS: Virgin female 8-month-old CD Sprague Dawley rats (N = 25) were ovariectomized. At 6 weeks, microstructured/non-nanostructured/hydrophobic, microstructured/nanostructured/hydrophobic, or microstructured/nanostructured/hydrophilic Ti implants (Ø2.5 × 3.5 mm; Institut Straumann AG, Basel, Switzerland) were placed in the distal metaphysis of each femur. At 28 days, bone quality and implant osseointegration were assessed using microCT, histomorphometrics, and removal torque values (RTVs). Calvarial osteoblasts were isolated and cultured for 7 days on Ø15 mm Ti disks processed to exhibit similar surface characteristics as the implants used for the in vivo studies. The phenotype was assessed by measuring the production of osteocalcin, osteoprotegerin, osteopontin, BMP2, VEGF, and RANKL. RESULTS: Microstructured/nanostructured/hydrophilic implants promoted increased bone-to-implant contact and RTVs in vivo and increased osteoblastic marker production in vitro compared to microstructured/non-nanostructured/hydrophobic and microstructured/nanostructured/hydrophobic implants, suggesting that osseointegration occurs in osteoporotic animals, and implant surface properties improve its rate. CONCLUSIONS: Although all modified implants were able to osseointegrate in rats with OVX-induced osteoporosis without pharmacologic intervention, the degree of osseointegration was greater around microstructured/nanostructured/hydrophilic implant surfaces. These results suggest that when appropriate microstructure is present, hydrophilicity has a greater influence on Ti implant osseointegration compared to nanostructures. Moreover, modified implant surfaces can exert their control over the altered bone turnover observed in osteoporotic patients to stimulate functional osseointegration. These results provide critical insight for developing implants with improved osseointegration in patients with metabolic disorders of bone remodeling.


Assuntos
Implantes Dentários , Osseointegração , Animais , Feminino , Humanos , Ovariectomia , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície , Suíça , Titânio
3.
Catheter Cardiovasc Interv ; 92(1): 106-114, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29521013

RESUMO

OBJECTIVES: To evaluate the clinical and health status outcomes of patients undergoing superficial femoral artery (SFA) revascularization using the Shape Memory Alloy Recoverable Technology (S.M.A.R.T.®) nitinol self-expanding stent through 3 years of follow-up. BACKGROUND: Limited long-term data are available describing the durability of benefits after femoropopliteal revascularization. METHODS: In a multicenter, prospective, core-lab adjudicated study, 250 subjects with de novo or restenotic femoropopliteal arterial lesions were treated with the S.M.A.R.T.® stent. The primary endpoint of target vessel patency, a composite of ultrasound-assessed patency and freedom from clinically driven target lesion revascularization (TLR), was evaluated through 3 years. Secondary endpoints included stent fracture and health status. Health status was measured using generic and disease-specific instruments, including the Peripheral Artery Questionnaire (PAQ). RESULTS: At 3-year follow-up, Kaplan-Meier estimated target vessel patency was 72.7%, freedom from clinically driven TLR was 78.5%, and the incidence of stent fracture was 3.6%. The PAQ summary score was markedly impaired at baseline (mean 37.3 ± 19.6 points) and improved substantially at 1 month (mean change from baseline of 31.4 points, 95% CI: 28.5-34.3; P < 0.001). Disease-specific health status benefits assessed by the PAQ were largely preserved through 3 years of follow-up (mean change from baseline, 28.0 points, 95% CI: 24.3-31.7; P < 0.0001). CONCLUSIONS: In patients undergoing revascularization for moderately complex SFA disease, use of the self-expanding S.M.A.R.T® stent was associated with a high rate of target vessel patency through 3 years and led to substantial and sustained health status benefits.


Assuntos
Procedimentos Endovasculares/instrumentação , Artéria Femoral/cirurgia , Doença Arterial Periférica/cirurgia , Artéria Poplítea/cirurgia , Qualidade de Vida , Stents Metálicos Autoexpansíveis , Idoso , Ligas , Constrição Patológica , Procedimentos Endovasculares/efeitos adversos , Feminino , Artéria Femoral/diagnóstico por imagem , Artéria Femoral/fisiopatologia , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/fisiopatologia , Doença Arterial Periférica/psicologia , Artéria Poplítea/diagnóstico por imagem , Artéria Poplítea/fisiopatologia , Intervalo Livre de Progressão , Estudos Prospectivos , Desenho de Prótese , Falha de Prótese , Inquéritos e Questionários , Fatores de Tempo , Ultrassonografia de Intervenção , Estados Unidos , Grau de Desobstrução Vascular
4.
Calcif Tissue Int ; 99(6): 625-637, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27501817

RESUMO

Direct metal laser sintering can produce porous Ti-6Al-4V orthopedic and dental implants. The process requires reduced resources and time and can provide greater structural control than machine manufacturing. Implants in bone are colonized by mesenchymal stem cells (MSCs), which can differentiate into osteoblasts and contribute to osseointegration. This study examined osteoblast differentiation and matrix mineralization of human MSCs cultured on laser-sintered Ti-6Al-4V constructs with varying porosity and at different time scales. 2D solid disks and low, medium and high porosity (LP, MP, and HP) 3D constructs based on a human trabecular bone template were laser sintered from Ti-6Al-4V powder and further processed to have micro- and nanoscale roughness. hMSCs exhibited greater osteoblastic differentiation and local factor production on all 3D porous constructs compared to 2D surfaces, which was sustained for 9 days without use of exogenous factors. hMSCs cultured for 8 weeks on MP constructs in osteogenic medium (OM), OM supplemented with BMP2 or collagen-coated MP constructs in OM exhibited bone-like extracellular matrix mineralization. Use of bio-inspired porosity for the 3D architecture of additively manufactured Ti-6Al-4V enhanced osteogenic differentiation of hMSCs beyond surface roughness alone. This study suggests that a 3D architecture may enhance the osseointegration of orthopedic and dental implants in vivo.


Assuntos
Calcificação Fisiológica/fisiologia , Implantes Dentários , Células-Tronco Mesenquimais/citologia , Osseointegração/fisiologia , Osteogênese/fisiologia , Diferenciação Celular/fisiologia , Humanos , Porosidade , Impressão Tridimensional
5.
Int J Cardiol ; 383: 24-32, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37080466

RESUMO

BACKGROUND: Biodegradable polymer biolimus-eluting stents (BP-BES) may be associated with better outcomes in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) compared to other current-generation limus-eluting stents (LES). AIMS: To compare BP-BES with other current-generation LES in ACS patients undergoing PCI. METHODS: We pooled individual data of Non-ST-segment elevation (NSTE)-ACS patients from two large randomized controlled trials (GLASSY and TWILIGHT). The BP-BES groups consisted mostly of GLASSY patients, while the control group (other current-generation LES) included exclusively TWILIGHT patients. The primary outcome was major adverse cardiovascular events (MACE), including cardiovascular death, myocardial infarction, or stent thrombosis; the key secondary outcome was target-vessel failure (TVF). To account for trial design differences, outcomes were assessed at 3 months (short-term) and between 3 and 12 months (long-term) after PCI and subsequently pooled to estimate the 12-month hazards. RESULTS: Of 7107 and 6053 NSTE-ACS patients included in the short- and long-term analysis, 32.7% and 36.5% received a BP-BES, respectively. Risk of MACE associated with BP-BES versus other LES was similar at short-term (1.1% vs 1.3%, adjusted HR 0.86, 95%CI 0.53-1.38), lower at long-term (1.7% vs 3.1%, adjusted HR 0.49, 95%CI 0.34-0.72), and lower in the entire 12-month period (pooled adjusted HR 0.61, 95%CI 0.45-0.82). The cumulative 12-month risk of TVF was reduced with BP-BES (adjusted HR 0.52, 95%CI 0.38-0.70). CONCLUSION: BP-BES was associated with lower 12-month risks of MACE and TVF compared to other current generation LES among NSTE-ACS patients treated with abbreviated or standard ticagrelor-based DAPT. These non-randomized findings are hypothesis-generating. CONDENSED ABSTRACT: Differences in clinical outcomes may exist between biodegradable polymer biolimus-eluting stents (BP-BES) and other current-generation limus-eluting stent (LES) in patients with acute coronary syndrome (ACS). We pooled individual data of about 7000 Non-ST-segment elevation ACS patients undergoing PCI and treated with ticagrelor with or without aspirin from two large randomized controlled trials (GLASSY and TWILIGHT). BP-BES patients derived very largely from GLASSY and other LES patients from TWILIGHT. In this population, BP-BES compared to other current generation LES, were associated with a lower 12-month risk of major adverse cardiovascular events and target-vessel failure.


Assuntos
Síndrome Coronariana Aguda , Stents Farmacológicos , Intervenção Coronária Percutânea , Humanos , Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/cirurgia , Síndrome Coronariana Aguda/etiologia , Sirolimo , Stents Farmacológicos/efeitos adversos , Intervenção Coronária Percutânea/efeitos adversos , Ticagrelor , Resultado do Tratamento , Stents , Polímeros , Implantes Absorvíveis
6.
Biomimetics (Basel) ; 7(2)2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-35466263

RESUMO

The use of metallic and polymeric materials for implants has been increasing over the past decade. This trend can be attributed to a variety of factors including a significant increase in basic science research focused on implant material characteristics and how various surface modifications may stimulate osseointegration and, ultimately, fusion. There are many interbody fusion devices and dental implants commercially available; however, detailed information about their surface properties, and the effects that various materials and surface modifications may have on osteogenesis, is lacking in the literature. While the concept of bone-implant osseointegration is a relatively recent addition to the spine fusion literature, there is a comparatively large body of literature related to dental implants. The purpose of this article is to summarize the science of surface modified bone-facing implants, focusing on biomimetic material chemistry and topography of titanium implants, to promote a better understanding of how these characteristics may impact bone formation and osseointegration. This manuscript has the following aspects: highlights the role of titanium and its alloys as potent osteoconductive bioactive materials; explores the importance of biomimetic surface topography at the macro-, micro- and nano-scale; summarizes how material surface design can influence osteogenesis and immune responses in vitro; focuses on the kinds of surface modifications that play a role in the process. Biomimetic surface modifications can be varied across many clinically available biomaterials, and the literature supports the hypothesis that those biomaterial surfaces that exhibit physical properties of bone resorption pits, such as roughness and complex hierarchical structures at the submicron and nanoscale, are more effective in supporting osteoblast differentiation in vitro and osteogenesis in vivo.

8.
Coron Artery Dis ; 31(3): 230-236, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31658137

RESUMO

OBJECTIVE: Use of poly-L-lactic acid-based bioresorbable scaffolds (BRS) has been associated with increased risk of device thrombosis during the first 3 years after implantation as compared to metallic everolimus-eluting stents (EES). The long-term performance of BRS relative to EES remains unknown. METHODS: We used a Markov decision analysis model to evaluate the effectiveness of BRS vs. EES over a lifetime horizon. In addition to one-way sensitivity analyses of key variables, we evaluated the impact of optimal implantation technique and limiting procedures to larger vessels (>2.6 mm in diameter) on model results. RESULTS: Assuming no risk of target lesion revascularization for BRS after 3 years, we found a small increment in quality-adjusted life expectancy (QALE) of 0.02 with the use of BRS relative to EES, with benefit being observed after 21.8 years. Optimal implantation technique and limiting to larger vessels resulted in larger gains in QALE (0.08 and 0.06, respectively) with BRS and shorter times to equipoise (6.7 and 8.3 years, respectively). Model results were highly sensitive to variations in the relative risk of stent thrombosis (BRS vs. EES). CONCLUSIONS: Based on currently available data, it would take approximately 21.8 years for the presumed late benefits of current BRS relative to EES to overcome the early hazard associated with their use under favorable assumptions. Optimal implantation technique and limiting procedures to larger vessels improved BRS performance and reduced time to equipoise. Eliminating the higher BRS thrombosis risk is necessary in developing future generations of BRS as an acceptable alternative to EES.


Assuntos
Implantes Absorvíveis , Angina Pectoris/cirurgia , Doença da Artéria Coronariana/cirurgia , Trombose Coronária/epidemiologia , Stents Farmacológicos , Intervenção Coronária Percutânea/métodos , Alicerces Teciduais , Antineoplásicos/administração & dosagem , Técnicas de Apoio para a Decisão , Everolimo/administração & dosagem , Humanos , Cadeias de Markov , Poliésteres , Complicações Pós-Operatórias/epidemiologia , Anos de Vida Ajustados por Qualidade de Vida , Medição de Risco
9.
J Biomed Mater Res B Appl Biomater ; 108(6): 2560-2570, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32086992

RESUMO

Burns and chronic wounds are especially challenging wounds to heal. In efforts to heal these wounds, physicians often use autologous skin grafts to help restore mechanical and barrier functionality to the wound area. These grafts are, by nature, limited in availability. In an effort to provide an alternative, we have developed an electrospun wound dressing designed to incorporate into the wound with the option to deliver a cellular payload. Here, a blend of poly(glycolic acid) and poly(ethylene glycol) was electrospun as part of a custom fabrication method that incorporated 3D printed poly(vinyl alcohol) sacrificial elements. This preparation is unique compared to traditional electrospinning as sacrificial elements provide an internal void space for an injectable payload to be delivered to the wound site. When the construct was tested in vivo (full thickness excisional skin wounds), wound closure was slightly delayed by the presence of the scaffold in both normal and challenged wounds. Quality of healing was improved in normal wounds as measured by histomorphometrics when treated with the construct and exhibited increased neovascularization. Our results demonstrate that the extracellular matrix-like scaffold developed in this study is beneficial to healing of full thickness skin defects and may benefit challenged wounds.


Assuntos
Bandagens , Pele/lesões , Cicatrização , Animais , Materiais Biocompatíveis , Sistemas de Liberação de Medicamentos , Matriz Extracelular , Humanos , Masculino , Neovascularização Fisiológica , Álcool de Polivinil , Impressão Tridimensional , Ratos , Ratos Sprague-Dawley , Transplante de Pele/métodos , Transplante de Células-Tronco , Alicerces Teciduais
10.
Biol Sex Differ ; 9(1): 30, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29970177

RESUMO

BACKGROUND: Osseointegration is dependent on the implant surface, surrounding bone quality, and the systemic host environment, which can differ in male and female patients. Titanium (Ti) implants with microstructured surfaces exhibit greater pullout strength when compared to smooth-surfaced implants and exhibit enhanced osteogenic cellular responses in vitro. Previous studies showed that 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3] has a greater effect on rat osteoblast differentiation on microstructured Ti compared to smooth Ti surfaces and tissue culture polystyrene (TCPS). The stimulatory effect of 17ß-estradiol (E2) on differentiation is observed in female osteoblasts on micro-rough Ti, but it is not known if male osteoblasts behave similarly in response to E2 and microtopography. This study assessed whether human male and female osteoblasts exhibit sex-specific differences in response to E2 and 1α,25(OH)2D3 when cultured on microstructured Ti surfaces. METHODS: Osteoblasts from three male and three female human donors were cultured on Ti discs with varying surface profiles: a smooth pretreatment (PT), a coarse grit-blasted/acid-etched (SLA), and an SLA surface having undergone modification in a nitrogen environment and stored in saline to maintain hydrophilicity (modSLA). Cells cultured on these surfaces were treated with E2 or 1α,25(OH)2D3. RESULTS: Male and female human osteoblasts responded similarly to microstructure although there were donor-specific differences; cell number decreased, and osteocalcin (OCN), osteoprotegerin (OPG), and latent and active transforming growth factor 1 increased on SLA and modSLA compared to TCPS. Female osteoblasts had higher alkaline phosphatase activity and OCN production than male counterparts but produced less OPG. Both sexes responded similarly to 1α,25(OH)2D3. E2 treatment reduced cell number and increased osteoblast differentiation and factor production only in female cells. CONCLUSIONS: Male and female human osteoblasts respond similarly to microstructure and 1α,25(OH)2D3 but exhibit sexual dimorphism in substrate-dependent responses to E2. E2 affected female osteoblasts, suggesting that signaling is sex-specific and surface-dependent. Donor osteoblasts varied in response, demonstrating the need to test multiple donors when examining human samples. Understanding how male and female cells respond to orthopedic biomaterials will enable greater predictability post-implantation as well as therapies that are more patient-specific.


Assuntos
Estradiol/farmacologia , Estrogênios/farmacologia , Osteoblastos/efeitos dos fármacos , Caracteres Sexuais , Titânio , Materiais Biocompatíveis , Células Cultivadas , Humanos , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Osteoprotegerina/metabolismo , Propriedades de Superfície , Vitamina D/análogos & derivados , Vitamina D/farmacologia
11.
Biomed Mater ; 12(2): 025021, 2017 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-28452335

RESUMO

Long term success of bone-interfacing implants remains a challenge in compromised patients and in areas of low bone quality. While surface roughness at the micro/nanoscale can promote osteogenesis, macro-scale porosity is important for promoting mechanical stability of the implant over time. Currently, machining techniques permit pores to be placed throughout the implant, but the pores are generally uniform in dimension. The advent of laser sintering provides a way to design and manufacture implants with specific porosity and variable dimensions at high resolution. This approach enables production of metal implants that mimic complex geometries found in biology. In this study, we used a rabbit femur model to compare osseointegration of laser sintered solid and porous implants. Ti-6Al-4V implants were laser sintered in a clinically relevant size and shape. One set of implants had a novel porosity based on human trabecular bone; both sets had grit-blasted/acid-etched surfaces. After characterization, implants were inserted transaxially into rabbit femora; mechanical testing, micro-computed tomography (microCT) and histomorphometry were conducted 10 weeks post-operatively. There were no differences in pull-out strength or bone-to-implant contact. However, both microCT and histomorphometry showed significantly higher new bone volume for porous compared to solid implants. Bone growth was observed into porous implant pores, especially near apical portions of the implant interfacing with cortical bone. These results show that laser sintered Ti-6Al-4V implants with micro/nanoscale surface roughness and trabecular bone-inspired porosity promote bone growth and may be used as a superior alternative to solid implants for bone-interfacing implants.


Assuntos
Fêmur/cirurgia , Lasers , Nanoestruturas/química , Osseointegração/fisiologia , Porosidade , Desenho de Prótese/métodos , Titânio/química , Ligas , Animais , Masculino , Teste de Materiais , Coelhos , Propriedades de Superfície , Titânio/efeitos da radiação , Microtomografia por Raio-X/métodos
12.
Ann Biomed Eng ; 45(8): 2025-2035, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28409291

RESUMO

The objective of this study was to examine the ability of 3D implants with trabecular-bone-inspired porosity and micro-/nano-rough surfaces to enhance vertical bone ingrowth. Porous Ti-6Al-4V constructs were fabricated via laser-sintering and processed to obtain micro-/nano-rough surfaces. Male and female human osteoblasts were seeded on constructs to analyze cell morphology and response. Implants were then placed on rat calvaria for 10 weeks to assess vertical bone ingrowth, mechanical stability and osseointegration. All osteoblasts showed higher levels of osteocalcin, osteoprotegerin, vascular endothelial growth factor and bone morphogenetic protein 2 on porous constructs compared to solid laser-sintered controls. Porous implants placed in vivo resulted in an average of 3.1 ± 0.6 mm3 vertical bone growth and osseointegration within implant pores and had significantly higher pull-out strength values than solid implants. New bone formation and pull-out strength was not improved with the addition of demineralized bone matrix putty. Scanning electron images and histological results corroborated vertical bone growth. This study indicates that Ti-6Al-4V implants fabricated by additive manufacturing to have porosity based on trabecular bone and post-build processing to have micro-/nano-surface roughness can support vertical bone growth in vivo, and suggests that these implants may be used clinically to increase osseointegration in challenging patient cases.


Assuntos
Desenvolvimento Ósseo/fisiologia , Osteoblastos/citologia , Osteoblastos/fisiologia , Osteogênese/fisiologia , Titânio/química , Ligas , Células Cultivadas , Análise de Falha de Equipamento , Feminino , Calefação/métodos , Humanos , Lasers , Masculino , Teste de Materiais , Porosidade , Pós , Desenho de Prótese , Propriedades de Superfície , Titânio/efeitos da radiação , Adulto Jovem
13.
J Biomed Mater Res A ; 105(10): 2742-2749, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28589712

RESUMO

Biologics can improve bone formation, but may diffuse away from sites of therapeutic need. We developed a click-chemistry hydrogel that rapidly polymerizes in situ to control delivery of biologics during post-suturectomy resynostosis in 21-day-old male mice. Here, we used this model to determine the role of angiogenesis in post-suturectomy resynostosis and examine whether controlled release of angiogenesis inhibitors could delay bone regeneration. Hydrogels [DB-co-PEG/poly (TEGDMA)-co-(N3-TEGDMA)] were produced containing anti-angiogenic compounds [anti-VEGFA-antibody or hypoxia inducible factor 1α-inhibitor topotecan]. Bioactivity in vitro was assessed by tube length and branching points of endothelial cells in hydrogel-conditioned media. In vivo effects were examined 14 day post-suturectomy, based on the temporal analysis of angiogenic mRNAs during resynostosis following posterior frontal suture removal. MicroCT was used to quantify angiogenesis in contrast-agent-perfused blood vessels and bone defect size in defects receiving hydrogel, anti-VEGFA/hydrogel, or topotecan/hydrogel. Shorter endothelial tube length and less branching were seen in inhibitor-conditioned media (topotecan > AbVEGFA). In vivo, both compounds inhibited angiogenesis compared with hydrogel-only. Anti-VEGFA/hydrogel reduced resynostosis compared with empty defects, but topotecan/hydrogel blocked bone regeneration. We demonstrate that anti-angiogenic compounds can be incorporated into a spontaneously polymerizing hydrogel and remain active over 14 days in vitro and in vivo. Moreover, bone formation can be delayed by inhibiting neovascularization, suggesting possible use as a therapeutic to control resynostosis following suturectomies and potential applications in other conditions where rapid osteogenesis is not desired. © 2017 Wiley Periodicals Inc. J Biomed Mater Res Part A: 105A: 2742-2749, 2017.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Regeneração Óssea/efeitos dos fármacos , Craniossinostoses/terapia , Preparações de Ação Retardada/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Osteogênese/efeitos dos fármacos , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Inibidores da Angiogênese/farmacologia , Animais , Craniossinostoses/complicações , Modelos Animais de Doenças , Sistemas de Liberação de Medicamentos , Masculino , Camundongos Endogâmicos C57BL , Topotecan/administração & dosagem , Topotecan/farmacologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
14.
Am J Cardiol ; 97(11): 1585-90, 2006 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-16728219

RESUMO

Clinical outcomes after multivessel versus single-vessel percutaneous coronary intervention (PCI) in the era of stents, glycoprotein IIb/IIIa inhibitors, and clopidogrel pretreatment have not been well studied. Thus, we compared outcomes from the Do Tirofiban and ReoPro Give Similar Efficacy Outcome Trial (TARGET) for patients who underwent multivessel versus single-vessel PCI and separately considered the effect of acute coronary syndromes on the results. Composite clinical outcomes (death, myocardial infarction, and target vessel revascularization) were evaluated at 30 days and 6 months and mortality at 1 year. Safety analysis included in-patient major and minor bleeding. Despite similar baseline characteristics, patients who underwent multivessel PCI (n = 775) had significantly higher 30-day and 6-month composite event rates than did those who were treated in a single coronary artery territory (n = 3,969). This association remained significant at 30 days (hazard ratio 1.57, 95% confidence interval 1.06 to 2.33, p = 0.025) after using propensity matching to minimize confounding factors. The higher event rate was primarily due to an increase in periprocedural myocardial infarction. However, there were no significant differences in propensity-matched ischemic outcomes at 6 months and 1 year or in bleeding. In addition, in a propensity-matched analysis that included 810 patients with acute coronary syndrome, multivessel stenting resulted in numerically more ischemic events than did single-vessel stenting, although this did not reach statistical significance (hazard ratio 1.32, 95% confidence interval 0.85 to 2.05, p = 0.221). In conclusion, multivessel PCI was more often associated with periprocedural myocardial infarction than single-vessel intervention, although this did not translate into higher 1-year mortality. A randomized trial comparing multivessel PCI with staged or surgical revascularization is warranted.


Assuntos
Angioplastia Coronária com Balão/métodos , Doença das Coronárias/terapia , Abciximab , Anticorpos Monoclonais/uso terapêutico , Implante de Prótese Vascular/instrumentação , Materiais Revestidos Biocompatíveis , Doença das Coronárias/mortalidade , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/uso terapêutico , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Stents , Taxa de Sobrevida/tendências , Tirofibana , Resultado do Tratamento , Tirosina/análogos & derivados , Tirosina/uso terapêutico
15.
Coron Artery Dis ; 17(8): 667-71, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17119374

RESUMO

Since their introduction, drug-eluting stents have rapidly altered modern medicine's approach to coronary artery disease. Before the development of drug-eluting stents, standard bare-metal stents were plagued by in-stent restenosis, requiring repeat revascularization in as many as 15-20% of patients during the first 6-12 months following implantation [1]. The currently approved drug-eluting stents have dramatically reduced this complication by using a polymer-impregnated coating that elutes either paclitaxel or sirolimus to inhibit smooth muscle proliferation. The pivotal TAXUS-IV [2] and SIRIUS [3] trials compared drug-eluting stents with standard bare-metal stents and found rates of target vessel revascularization ranging from 3 to 4.1% in stable coronary artery disease patients - far lower than that had been seen previously with conventional standard bare-metal stents. After their approval in April 2003, drug-eluting stents use in clinical practice expanded rapidly. Within 9 months of their introduction, drug-eluting stents comprised 35% of all stent implantations in the United States [4]. In the last year at our own institution, drug-eluting stents comprised over 85% of all stents implanted. Despite their extensive use, data regarding the efficacy and safety of drug-eluting stents in certain clinical scenarios are limited. To date, the only published data supporting drug-eluting stents in ST[corrected]-elevation acute myocardial infarction come from the retrospective Rapamycin-Eluting Stent Evaluated at Rotterdam Cardiology Hospital registry [5] and the randomized, controlled single high-dose bolus tirofiban and sirolimus-eluting stent vs. abciximab and bare-metal stent in myocardial infarction study [6]. In this chapter, we discuss the theoretical risks and benefits of drug-eluting stents for ST elevation acute myocardial infarction, the available data regarding their use, and the areas in which future studies are needed.


Assuntos
Materiais Revestidos Biocompatíveis/efeitos adversos , Trombose Coronária/complicações , Infarto do Miocárdio/etiologia , Revascularização Miocárdica/instrumentação , Stents/efeitos adversos , Estenose Coronária/cirurgia , Humanos , Falha de Prótese , Fatores de Risco
16.
J Biomed Mater Res A ; 104(8): 2086-98, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27086616

RESUMO

The purpose of this study was to compare the biological effects in vivo of hierarchical surface roughness on laser sintered titanium-aluminum-vanadium (Ti-6Al-4V) implants to those of conventionally machined implants on osteoblast response in vitro and osseointegration. Laser sintered disks were fabricated to have micro-/nano-roughness and wettability. Control disks were computer numerical control (CNC) milled and then polished to be smooth (CNC-M). Laser sintered disks were polished smooth (LST-M), grit blasted (LST-B), or blasted and acid etched (LST-BE). LST-BE implants or implants manufactured by CNC milling and grit blasted (CNC-B) were implanted in the femurs of male New Zealand white rabbits. Most osteoblast differentiation markers and local factors were enhanced on rough LST-B and LST-BE surfaces in comparison to smooth CNC-M or LST-M surfaces for MG63 and normal human osteoblast cells. To determine if LST-BE implants were osteogenic in vivo, we compared them to implant surfaces used clinically. LST-BE implants had a unique surface with combined micro-/nano-roughness and higher wettability than conventional CNC-B implants. Histomorphometric analysis demonstrated a significant improvement in cortical bone-implant contact of LST-BE implants compared to CNC-B implants after 3 and 6 weeks. However, mechanical testing revealed no differences between implant pullout forces at those time points. LST surfaces enhanced osteoblast differentiation and production of local factors in vitro and improved the osseointegration process in vivo. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2086-2098, 2016.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Lasers , Nanoestruturas/química , Osseointegração/efeitos dos fármacos , Osteoblastos/citologia , Titânio/farmacologia , Ligas , Animais , Linhagem Celular , Humanos , Implantes Experimentais , Masculino , Teste de Materiais , Modelos Animais , Osteoblastos/efeitos dos fármacos , Coelhos , Espectrometria por Raios X , Molhabilidade , Microtomografia por Raio-X
17.
JACC Cardiovasc Interv ; 9(22): 2343-2352, 2016 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-27884360

RESUMO

OBJECTIVES: The aim of this study was to evaluate the cost-effectiveness of drug-coated balloon (DCB) angioplasty versus standard percutaneous transluminal angioplasty (PTA). BACKGROUND: Recent trials have reported lower rates of target lesion revascularization with DCB angioplasty versus standard PTA. However, the cost-effectiveness of DCB angioplasty is unknown. METHODS: A prospective economic study was performed alongside the IN.PACT SFA II (IN.PACT Admiral Drug-Coated Balloon vs. Standard Balloon Angioplasty for the Treatment of Superficial Femoral Artery [SFA] and Proximal Popliteal Artery [PPA]) trial, which randomized 181 patients with femoropopliteal disease to the IN.PACT DCB versus standard PTA. Resource use data were collected over 2-year follow-up, and costs were assigned using resource-based accounting and billing data. Health utilities were assessed using the EuroQol 5-dimensions questionnaire. Cost-effectiveness was assessed as cost per quality-adjusted life-year (QALY) gained using a decision-analytic model on the basis of empirical data from the trial assuming identical long-term mortality. RESULTS: Initial costs were $1,129 per patient higher with DCB angioplasty than standard PTA, driven by higher costs for the DCB itself. Between discharge and 24 months, target limb-related costs were $1,212 per patient lower with DCB angioplasty such that discounted 2-year costs were similar for the 2 groups ($11,277 vs. $11,359, p = 0.97), whereas QALYs tended to be greater among patients treated with DCBs (1.53 ± 0.44 vs. 1.47 ± 0.42, p = 0.40). The probability that DCB angioplasty is cost-effective compared with standard PTA was 70% using a threshold of $50,000 per QALY gained and 79% at a threshold of $150,000 per QALY gained. CONCLUSIONS: For patients with femoropopliteal disease, DCB angioplasty is associated with better 2-year outcomes and similar target limb-related costs compared with standard PTA. Formal cost-effectiveness analysis on the basis of these results suggests that use of the DCB angioplasty is likely to be economically attractive.


Assuntos
Angioplastia com Balão/economia , Angioplastia com Balão/instrumentação , Fármacos Cardiovasculares/economia , Materiais Revestidos Biocompatíveis/economia , Artéria Femoral , Custos de Cuidados de Saúde , Doença Arterial Periférica/economia , Doença Arterial Periférica/terapia , Artéria Poplítea , Dispositivos de Acesso Vascular/economia , Idoso , Angioplastia com Balão/efeitos adversos , Fármacos Cardiovasculares/administração & dosagem , Constrição Patológica , Redução de Custos , Análise Custo-Benefício , Técnicas de Apoio para a Decisão , Custos de Medicamentos , Desenho de Equipamento , Feminino , Artéria Femoral/diagnóstico por imagem , Artéria Femoral/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Econômicos , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/fisiopatologia , Artéria Poplítea/diagnóstico por imagem , Artéria Poplítea/fisiopatologia , Estudos Prospectivos , Anos de Vida Ajustados por Qualidade de Vida , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
18.
Ann Thorac Surg ; 77(2): 537-43, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14759434

RESUMO

BACKGROUND: Calcific aortic stenosis is a major public health problem in the United States. The mechanism of calcification remains unclear. The hypothesis that low grade chronic or recurrent bacterial endocarditis with specific calcifiable bacteria is a cause of calcification of the aortic valves was investigated using an animal model. Such bacteria are typically present as part of the normal human oral flora. METHODS: Forty New Zealand white rabbits were divided into four groups: group 1, control (1 ml of normal saline); group 2, Corynebacterium matruchotti 100,000 colonies; group 3, Streptococcus sanguis II 10 colonies; and group 4, C matruchotti 100,000 colonies plus S sanguis II 10 colonies. Animals were inoculated with bacteria through a flexible catheter placed through the aortic valve through a right carotid cut down. Inoculations were repeated every 3 days the first 2 weeks and then twice a week thereafter. At postmortem examination the aortic valves were harvested, embedded in paraffin, and stained with von Kossa stain. They were also examined by scanning and transmission electron micrography. RESULTS: Group 4 had 93.3% large calcifications (confluent calcium densities that are easily recognized with minimal magnification) and 6.6% small microcalcifications (dustlike microscopic particles requiring a compound microscope to appreciate) of the aortic valves. Group 3 exhibited large calcification in 20% and small in 40% of the aortic valves. Group 1 and group 2 had no evidence of calcification. CONCLUSIONS: These results suggest that recurrent low-grade endocarditis from calcifying oral bacteria, particularly when occurring with synergistic strains, may be one cause of calcific aortic stenosis.


Assuntos
Estenose da Valva Aórtica/microbiologia , Calcinose/microbiologia , Infecções por Corynebacterium/microbiologia , Modelos Animais de Doenças , Mucosa Bucal/microbiologia , Infecções Estreptocócicas/microbiologia , Animais , Valva Aórtica/microbiologia , Valva Aórtica/patologia , Estenose da Valva Aórtica/patologia , Bacteriemia/microbiologia , Bacteriemia/patologia , Calcinose/patologia , Cálcio/análise , Doença Crônica , Contagem de Colônia Microbiana , Corynebacterium/patogenicidade , Infecções por Corynebacterium/patologia , Placa Dentária/microbiologia , Endocardite Bacteriana/microbiologia , Masculino , Microscopia Eletrônica de Varredura , Mucosa Bucal/patologia , Coelhos , Fatores de Risco , Infecções Estreptocócicas/patologia , Streptococcus sanguis/patogenicidade , Virulência
19.
J Invasive Cardiol ; 15(3): 121-7, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12612385

RESUMO

BACKGROUND: Percutaneous coronary intervention (PCI) using balloon angioplasty and/or intracoronary stents has increasingly become the treatment choice for myocardial revascularization. While acute clinical outcomes of the community-based PCI procedures have been examined, much less is known about long-term revascularization rates, disease progression and other adverse outcomes. METHODS AND RESULTS: Information on patient demographics, coronary risk factors, lesion characteristics, procedures and outcomes were derived from an HCA, Inc. database on all patients undergoing a PCI procedure in one of four community cardiac catheterization laboratories. A total of 3,192 consecutive patients were enrolled from July 1, 1999 through September 30, 2000. Analysis was limited to those patients undergoing PCI of native vessels with stents or conventional balloon angioplasty; target lesions in bypass grafts or those treated with atherectomy were excluded. Approximately one-third of enrolled patients were surveyed concerning their utilization of cardiovascular services 1 year following their initial procedure. The 1-year target lesion revascularization (TLR) was 9.9% while target vessel revascularization was 13.5%. Overall, 27.6% of patients underwent repeat revascularization within 1 year; 24.7% underwent at least 1 additional PCI and 5.6% underwent coronary artery bypass graft surgery. A total of 4.5% of patients reported an interval acute myocardial infarction with a major adverse cardiac event rate of 30.3% at 1 year. CONCLUSION: While clinically significant restenosis remains a problem for 10 15% of patients undergoing PCI, progression of coronary artery disease elsewhere appears to be an equally powerful driver in the need for recurrent revascularization. This analysis of contemporary PCI practice prior to drug-eluting stent utilization suggests that while these novel devices will likely reduce the incidence of TLR, many patients with coronary artery disease will still require additional revascularization for disease progression.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Materiais Revestidos Biocompatíveis/uso terapêutico , Doença da Artéria Coronariana/terapia , Stents , Idoso , Implante de Prótese Vascular , Serviços de Saúde Comunitária , Doença da Artéria Coronariana/diagnóstico por imagem , Bases de Dados Factuais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Radiografia , Resultado do Tratamento
20.
Biofabrication ; 6(4): 045007, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25287305

RESUMO

Additive manufacturing by laser sintering is able to produce high resolution metal constructs for orthopedic and dental implants. In this study, we used a human trabecular bone template to design and manufacture Ti-6Al-4V constructs with varying porosity via laser sintering. Characterization of constructs revealed interconnected porosities ranging from 15-70% with compressive moduli of 2579-3693 MPa. These constructs with macro porosity were further surface-treated to create a desirable multi-scale micro-/nano-roughness, which has been shown to enhance the osseointegration process. Osteoblasts (MG63 cells) exhibited high viability when grown on the constructs. Proliferation (DNA) and alkaline phosphatase specific activity, an early differentiation marker, decreased as porosity increased, while osteocalcin, a late differentiation marker, as well as osteoprotegerin, vascular endothelial growth factor and bone morphogenetic proteins 2 and 4 increased with increasing porosity. Three-dimensional (3D) constructs with the highest porosity and surface modification supported the greatest osteoblast differentiation and local factor production. These results indicate that additively manufactured 3D porous constructs mimicking human trabecular bone and produced with additional surface treatment can be customized for increased osteoblast response. Increased factors for osteoblast maturation and differentiation on high porosity constructs suggest the enhanced performance of these surfaces for increasing osseointegration in vivo.


Assuntos
Materiais Biocompatíveis/química , Osteoblastos/citologia , Propriedades de Superfície , Alicerces Teciduais , Titânio/química , Ligas , Diferenciação Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos , Engenharia Tecidual , Titânio/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA