RESUMO
Hydrogels are a class of biomaterials that can provide a three-dimensional (3D) environment capable of mimicking the extracellular matrix of native tissues. In this chapter, we present a method to generate electrospun nanofibers for the purpose of reinforcing hydrogels. The addition of electrospun fibers can be used to improve the mechanical properties of hydrogels and broaden their range of applications. First, the polymer for making the electrospun fibers is formulated using chloroform/ethanol, polycaprolactone (PCL), polyethylene glycol (PEG), and polyethylene glycol diacrylate (PEGDA). Second, the polymer is used to generate thin electrospun nanofibers by an electrospinning technique using aluminum foil as a collector, which acts as the conductive substrate that collects the charged fibers. Third, the resulting electrospun fibers undergo a filtration process using nylon membrane filters, followed by lyophilization, ensuring complete removal of water from the sample.
Assuntos
Hidrogéis , Nanofibras , Polietilenoglicóis , Nanofibras/química , Polietilenoglicóis/química , Hidrogéis/química , Materiais Biocompatíveis/química , Humanos , Terapia Baseada em Transplante de Células e Tecidos/métodos , Poliésteres/química , Alicerces Teciduais/química , Engenharia Tecidual/métodosRESUMO
Heart disease remains the leading cause of worldwide mortality. Although the last decades have broadened our understanding of the biology behind the pathologies of heart disease, ex vivo systems capable of mimicking disease progression and abnormal heart function using human cells remain elusive. In this contribution, an open-access electromechanical system (BEaTS-ß) capable of mimicking the environment of cardiac disease is reported. BEaTS-ß was designed using computer-aided modeling to combine tunable electrical stimulation and mechanical deformation of cells cultured on a flexible elastomer. To recapitulate the clinical scenario of a heart attack more closely, in designing BEaTS-ß we considered a device capable to operate under hypoxic conditions. We tested human induced pluripotent stem cell-derived cardiomyocytes, fibroblasts, and coronary artery endothelial cells in our simulated myocardial infarction environment. Our results indicate that, under simulated myocardium infarction, there was a decrease in maturation of cardiomyocytes, and reduced survival of fibroblasts and coronary artery endothelial cells. The open access nature of BEaTS-ß will allow for other investigators to use this platform to investigate cardiac cell biology or drug therapeutic efficacy in vitro under conditions that simulate arrhythmia and/or myocardial infarction.
RESUMO
BACKGROUND: The objective of this study is to evaluate the trends of and outcomes associated with the use of minimally invasive lobectomy for stage I and II non-small cell lung cancer (NSCLC) in the United States. METHODS: The use of and outcomes associated with open and minimally invasive lobectomy for clinical stage I and stage II NSCLC from 2010 to 2017 in the National Cancer Database were assessed by multivariable logistic regression and propensity score matching. RESULTS: From 2010 to 2017, use of minimally invasive lobectomies increased for stage I NSCLC (multivariable-adjusted odds ratio [aOR] 4.52; 95% CI, 3.95-5.18; P < .001) and stage II NSCLC (aOR 4.38; 95% CI, 3.38-5.68; P < .001). In 2015, for the first time, more lobectomies for stage I NSCLC were performed by minimally invasive techniques (52.2%, n = 5647) than by thoracotomy (47.8%, n = 5164); and in 2017, more lobectomies for stage II NSCLC were performed by minimally invasive techniques (54.7%, n = 1620) than by thoracotomy (45.3%, n = 1,342). From 2010 to 2017, the conversion rates from minimally invasive to open lobectomy for stage I NSCLC decreased from 19.6% (n = 466) to 7.2% (n = 521; aOR 0.32; 95% CI, 0.23-0.43; P < .001). Similarly, from 2010 to 2017, the conversion rates from minimally invasive to open lobectomy for stage II NSCLC decreased from 20% (n = 114) to 11.5% (n = 186; aOR 0.39; 95% CI, 0.21-0.72; P = .002). CONCLUSIONS: In the United States, for stage I and stage II NSCLC from 2010 to 2017, the use of minimally invasive lobectomy significantly increased while the conversion rate significantly decreased. By 2017, the minimally invasive approach had become the predominant approach for both stage I and stage II NSCLC.