RESUMO
Following the COVID-19 outbreak, swabs for biological specimen collection were thrust to the forefront of healthcare materials. Swab sample collection and recovery are vital for reducing false negative diagnostic tests, early detection of pathogens, and harvesting DNA from limited biological samples. In this study, we report a new class of nanofiber swabs tipped with hierarchical 3D nanofiber objects produced by expanding electrospun membranes with a solids-of-revolution-inspired gas foaming technique. Nanofiber swabs significantly improve absorption and release of proteins, cells, bacteria, DNA, and viruses from solutions and surfaces. Implementation of nanofiber swabs in SARS-CoV-2 detection reduces the false negative rates at two viral concentrations and identifies SARS-CoV-2 at a 10× lower viral concentration compared to flocked and cotton swabs. The nanofiber swabs show great promise in improving test sensitivity, potentially leading to timely and accurate diagnosis of many diseases.
Assuntos
Teste para COVID-19/instrumentação , COVID-19/diagnóstico , Nanofibras , SARS-CoV-2 , COVID-19/virologia , Teste para COVID-19/métodos , Teste para COVID-19/estatística & dados numéricos , Reações Falso-Negativas , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Nanofibras/ultraestrutura , Nanotecnologia , SARS-CoV-2/isolamento & purificação , Manejo de Espécimes/instrumentação , Manejo de Espécimes/métodos , Manejo de Espécimes/estatística & dados numéricosRESUMO
Electrostatic flocking, a textile engineering technique, uses Coulombic driving forces to propel conductive microfibers toward an adhesive-coated substrate, leaving a forest of aligned fibers. Though an easy way to induce anisotropy along a surface, this technique is limited to microfibers capable of accumulating charge. This study reports a novel method, utilizing principles from the percolation theory to make electrically insulative polymeric microfibers flockable. A variety of well-mixed, conductive materials are added to multiple insulative and biodegradable polymer microfibers during wet spinning, which enables nearly all types of polymer microfibers to accumulate sufficient charges required for flocking. Biphasic, biodegradable scaffolds are fabricated by flocking silver nanoparticle (AgNP)-filled poly(ε-caprolactone) (PCL) microfibers onto substrates made from 3D printing, electrospinning, and thin-film casting. The incorporation of AgNP into PCL fibers and use of chitosan-based adhesive enables antimicrobial activity against methicillin-resistant Staphylococcus aureus. The fabricated scaffolds demonstrate both favorable in vitro cell response and new tissue formation after subcutaneous implantation in rats, as evident by newly formed blood vessels and infiltrated cells. This technology opens the door for using previously unflockable polymer microfibers as surface modifiers or standalone structures in various engineering fields.
Assuntos
Nanopartículas Metálicas , Staphylococcus aureus Resistente à Meticilina , Animais , Poliésteres , Polímeros , Ratos , Prata , Eletricidade Estática , Engenharia Tecidual , Alicerces TeciduaisRESUMO
Resumen En la actualidad, México ocupa el primer lugar con obesidad infantil y el segundo con obesidad en el adulto. Este fenómeno ya ha alcanzado niveles de pandemia, por lo que de no evitar que continúe aumentando el número de pacientes obesos, en pocos años la cantidad de discapacitados a causa de alteraciones metabólicas será alarmante. En esta revisión se pretenden establecer las causas del síndrome metabólico, los mecanismos que se alteran para conducirá diabetes mellitus, y se mencionan los mecanismos fisiológicos que se alteran en la condición de hiperglucemia. Y dentro de las consecuencias que resultan de esta enfermedad, analizar una de las que más cuesta al paciente y a la familia como lo es el pie diabético.
Abstract Mexico currently occupies the first place with childhood obesity and the second with adult obesity. This phenomenon has already reached pandemic levels so if the increasing number of obese patients is not prevented, in a fewyears the number of patients with disabilities resulting from metabolic alterations will be alarming. This review aims to establish the causes of the metabolic syndrome, the mechanisms that are altered and lead to diabetes mellitus, also we will mention the physiological mechanisms altered in hyperglycemia and its consequences. We will analyze one of the diseases with the highest costs for the patient and their family: the diabetic foot.