RESUMO
Optical biosensors support disease diagnostic applications, offering high accuracy and sensitivity due to label-free detection and their optical resonance enhancement. However, optical biosensors based on noble metal nanoparticles and precise micro-electromechanical system technology are costly, which is an obstacle for their applications. Here, we proposed a biosensor reuse method with nanoscale parylene C film, taking the silicon-on-insulator microring resonator biosensor as an example. Parylene C can efficiently adsorb antibody by one-step modification without any surface treatment, which simplifies the antibody modification process of sensors. Parylene C (20 nm thick) was successfully coated on the surface of the microring to modify anti-carcinoembryonic antigen (anti-CEA) and specifically detect CEA. After sensing, parylene C was successfully removed without damaging the sensing surface for the sensor reusing. The experimental results demonstrate that the sensing response did not change significantly after the sensor was reused more than five times, which verifies the repeatability and reliability of the reusable method by using parylene C. This framework can potentially reduce the cost of biosensors and promote their further applications.
Assuntos
Técnicas Biossensoriais , Silício , Polímeros , Regeneração , Reprodutibilidade dos Testes , XilenosRESUMO
Microfluidic devices have emerged as revolutionary, novel platforms for in vitro drug evaluation. In this work, we developed a facile method for evaluating antihypertensive drugs using a microfluidic chip. This microfluidic chip was generated using the elastic material poly(dimethylsiloxane) (PDMS) and a microchannel structure that simulated a blood vessel as fabricated on the chip. We then cultured human umbilical vein endothelial cells (HUVECs) inside the channel. Different pressures and shear stresses could be applied on the cells. The generated vessel mimics can be used for evaluating the safety and effects of antihypertensive drugs. Here, we used hydralazine hydrochloride as a model drug. The results indicated that hydralazine hydrochloride effectively decreased the pressure-induced dysfunction of endothelial cells. This work demonstrates that our microfluidic system provides a convenient and cost-effective platform for studying cellular responses to drugs under mechanical pressure.
Assuntos
Anti-Hipertensivos/farmacologia , Materiais Biomiméticos/farmacologia , Biomimética/métodos , Dispositivos Lab-On-A-Chip/métodos , Anti-Hipertensivos/química , Materiais Biomiméticos/química , Vasos Sanguíneos/efeitos dos fármacos , Células Cultivadas , Dimetilpolisiloxanos/química , Avaliação de Medicamentos/métodos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Hidralazina/química , Hidralazina/farmacologia , Técnicas In Vitro/métodos , Microfluídica/métodos , Nylons/química , Pressão , Resistência ao Cisalhamento/efeitos dos fármacos , Estresse MecânicoRESUMO
As Alzheimer's disease prevalence continues to rise, there is an increasing demand for efficient on-chip biosensors capable of early biomarker detection. This study presents a novel biosensor chip leveraging vertical cavity surface emitting laser (VCSEL) technology, with Parylene C serving as the antibody coupling layer and utilizing a streamlined one-step antibody modification method. Integration of Parylene C enhances chip sensitivity from 34.28 µW/RIU to 40.32 µW/RIU. Moreover, post-testing removal of Parylene C enables chip reusability without significant alteration of results. The sensor demonstrates effective detection of Aß42, an Alzheimer's biomarker, exhibiting a linear range of 1-200 ng/mL and a detection limit of 0.26 ng/mL. These findings underscore the reusability and reliability of the ultrathin Parylene C-based VCSEL biosensor chip, highlighting its potential for point-of-care Alzheimer's disease diagnosis.
Assuntos
Doença de Alzheimer , Técnicas Biossensoriais , Polímeros , Xilenos , Humanos , Técnicas Biossensoriais/métodos , Doença de Alzheimer/diagnóstico , Reprodutibilidade dos Testes , Lasers , BiomarcadoresRESUMO
Cell migration and invasion are important factors during tumor progression and metastasis. Wound-healing assay and the Boyden chamber assay are efficient tools to investigate tumor development because both of them could be applied to measure cell migration rate. Therefore, a simple and integrated polydimethylsiloxane (PDMS) device was developed for cell migration assay, which could perform quantitative evaluation of cell migration behaviors, especially for the wound-healing assay. The integrated device was composed of three units, which included cell culture dish, PDMS chamber, and wound generation mold. The PDMS chamber was integrated with cell culture chamber and could perform six experiments under different conditions of stimuli simultaneously. To verify the function of this device, it was utilized to explore the tumor cell migration behaviors under different concentrations of fetal bovine serum (FBS) and transforming growth factor (TGF-ß) at different time points. This device has the unique capability to create the "wound" area in parallel during cell migration assay and provides a simple and efficient platform for investigating cell migration assay in biomedical application.