A CMOS Multi-Modal Electrochemical and Impedance Cellular Sensing Array for Massively Paralleled Exoelectrogen Screening.

The paper presents a 256-pixel CMOS sensor array with in-pixel dual electrochemical and impedance detection modalities for rapid, multi-dimensional characterization of exoelectrogens. The CMOS IC has 16 parallel readout channels, allowing it to perform multiple measurements with a high throughput and enable the chip to handle different samples simultaneously. The chip contains a total of 2 × 256 working electrodes of size 44 µm × 52 µm, along with 16 reference electrodes of dimensions 56 µm × 399 µm and 32 counter electrodes of dimensions 399 µm × 106 µm, which together facilitate the high resolution screening of the test samples. The chip was fabricated in a standard 130nm BiCMOS process. The on-chip electrodes are subjected to additional fabrication processes, including a critical Al-etch step that ensures the excellent biocompatibility and long-term reliability of the CMOS sensor array in bio-environment. The electrochemical sensing modality is verified by detecting the electroactive analyte NaFeEDTA and the exoelectrogenic Shewanella oneidensis MR-1 bacteria, illustrating the chip's ability to quantify the generated electrochemical current and distinguish between different analyte concentrations. The impedance measurements with the HEK-293 cancer cells cultured on-chip successfully capture the cell-to-surface adhesion information between the electrodes and the cancer cells. The reported CMOS sensor array outperforms the conventional discrete setups for exoelectrogen characterization in terms of spatial resolution and speed, which demonstrates the chip's potential to radically accelerate synthetic biology engineering.

Engineered Cardiac Pacemaker Nodes Created by TBX18 Gene Transfer Overcome Source-Sink Mismatch.

Every heartbeat originates from a tiny tissue in the heart called the sinoatrial node (SAN). The SAN harbors only ≈10 000 cardiac pacemaker cells, initiating an electrical impulse that captures the entire heart, consisting of billions of cardiomyocytes for each cardiac contraction. How these rare cardiac pacemaker cells (the electrical source) can overcome the electrically hyperpolarizing and quiescent myocardium (the electrical sink) is incompletely understood. Due to the scarcity of native pacemaker cells, this concept of source-sink mismatch cannot be tested directly with live cardiac tissue constructs. By exploiting TBX18 induced pacemaker cells by somatic gene transfer, 3D cardiac pacemaker spheroids can be tissue-engineered. The TBX18 induced pacemakers (sphTBX18) pace autonomously and drive the contraction of neighboring myocardium in vitro. TBX18 spheroids demonstrate the need for reduced electrical coupling and physical separation from the neighboring ventricular myocytes, successfully recapitulating a key design principle of the native SAN. ß-Adrenergic stimulation as well as electrical uncoupling significantly increase sphTBX18s' ability to pace-and-drive the neighboring myocardium. This model represents the first platform to test design principles of the SAN for mechanistic understanding and to better engineer biological pacemakers for therapeutic translation.

Induced cardiac pacemaker cells survive metabolic stress owing to their low metabolic demand.

Cardiac pacemaker cells of the sinoatrial node initiate each and every heartbeat. Compared with our understanding of the constituents of their electrical excitation, little is known about the metabolic underpinnings that drive the automaticity of pacemaker myocytes. This lack is largely owing to the scarcity of native cardiac pacemaker myocytes. Here, we take advantage of induced pacemaker myocytes generated by TBX18-mediated reprogramming (TBX18-iPMs) to investigate comparative differences in the metabolic program between pacemaker myocytes and working cardiomyocytes. TBX18-iPMs were more resistant to metabolic stresses, exhibiting higher cell viability upon oxidative stress. TBX18-induced pacemaker myocytes (iPMs) expensed a lower degree of oxidative phosphorylation and displayed a smaller capacity for glycolysis compared with control ventricular myocytes. Furthermore, the mitochondria were smaller in TBX18-iPMs than in the control. We reasoned that a shift in the balance between mitochondrial fusion and fission was responsible for the smaller mitochondria observed in TBX18-iPMs. We identified a mitochondrial inner membrane fusion protein, Opa1, as one of the key mediators of this process and demonstrated that the suppression of Opa1 expression increases the rate of synchronous automaticity in TBX18-iPMs. Taken together, our data demonstrate that TBX18-iPMs exhibit a low metabolic demand that matches their mitochondrial morphology and ability to withstand metabolic insult.

Intracellular cardiomyocytes potential recording by planar electrode array and fibroblasts co-culturing on multi-modal CMOS chip.

Intracellular action potential signals reveal enriched physiological information. Patch clamp techniques have been widely used to measure intracellular potential. Despite their high signal fidelity, they suffer from low throughput. Recently, 3D nanoelectrodes have been developed for intracellular potential recording. However, they are limited by scalability, yield, and cost, directly constraining their use in monitoring large number of cells and high throughput applications. In this paper, we demonstrate intracellular potential monitoring of cardiomyocytes using simple 2D planar electrode array in a standard CMOS process without patch clamps or post fabricated 3D nanoelectrodes. This is enabled by our unique cardiomyocytes/fibroblasts co-culturing technique and electroporation. The co-cultured fibroblasts promote tight sealing of cardiomyocytes on electrodes and enable high-fidelity intracellular potential monitoring based on 2D planar electrode. Compared to existing technologies, our platform has a unique potential to achieve an unprecedented combination of throughput, spatiotemporal resolution, and a tissue-level field-of-view for cellular electrophysiology monitoring.

Multi-parametric cell profiling with a CMOS quad-modality cellular interfacing array for label-free fully automated drug screening.

Cells are complex systems with concurrent multi-physical responses, and cell physiological signals are often encoded with spatiotemporal dynamics and further coupled with multiple cellular activities. However, most existing electronic sensors are only single-modality and cannot capture multi-parametric cellular responses. In this paper, a 1024-pixel CMOS quad-modality cellular interfacing array that enables multi-parametric cell profiling for drug development is presented. The quad-modality CMOS array features cellular impedance characterization, optical detection, extracellular potential recording, and biphasic current stimulation. The fibroblast transparency and surface adhesion are jointly monitored by cellular impedance and optical sensing modalities for comprehensive cell growth evaluation. Simultaneous current stimulation and opto-mechanical monitoring based on cardiomyocytes are demonstrated without any stimulation/sensing dead-zone. Furthermore, drug dose-dependent multi-parametric feature extractions in cardiomyocytes from their extracellular potentials and opto-mechanical signals are presented. The CMOS array demonstrates great potential for fully automated drug screening and drug safety assessments, which may substantially reduce the drug screening time and cost in future new drug development.

1024-Pixel CMOS Multimodality Joint Cellular Sensor/Stimulator Array for Real-Time Holistic Cellular Characterization and Cell-Based Drug Screening.

This paper presents a fully integrated CMOS multimodality joint sensor/stimulator array with 1024 pixels for real-time holistic cellular characterization and drug screening. The proposed system consists of four pixel groups and four parallel signal-conditioning blocks. Every pixel group contains 16 × 16 pixels, and each pixel includes one gold-plated electrode, four photodiodes, and in-pixel circuits, within a pixel footprint. Each pixel supports real-time extracellular potential recording, optical detection, charge-balanced biphasic current stimulation, and cellular impedance measurement for the same cellular sample. The proposed system is fabricated in a standard 130-nm CMOS process. Rat cardiomyocytes are successfully cultured on-chip. Measured high-resolution optical opacity images, extracellular potential recordings, biphasic current stimulations, and cellular impedance images demonstrate the unique advantages of the system for holistic cell characterization and drug screening. Furthermore, this paper demonstrates the use of optical detection on the on-chip cultured cardiomyocytes to real-time track their cyclic beating pattern and beating rate.

Diagnóstico socioestomatológico de los municipios de Estanzuelas, Ciudad el Triunfo, Puerto el Triunfo y Concepción Batres del departamento de Usulután, de la República de El salvador durante el período de abril a septiembre de 2001 / Socio-stomatological diagnosis of the municipalities of Estanzuelas, Ciudad el Triunfo, Puerto el Triunfo and Concepción Batres of the department of Usulután, of the Republic of El Salvador during the period from April to September 2001

El presente trabajo consta de 4 fases. En la primera fase de este trabajo se plantea en primer lugar la justificación del trabajo la cual consiste en la importancia de realizar este estudio así como también la utilidad que tiene este trabajo de investigación, seguido se presenta el objetivo general en el cual se plantea realizar el diagnóstico de la realidad socioestomatológica de los municipios en estudio; posteriormente los objetivos específicos, se verifica el presupuesto asignado por el MSPAS al área estomatológica la existencia de un control por parte de la junta de vigilancia y se constata el número de piezas cariadas, perdidas y obturadas de los pacientes por estratos que asisten a las clínicas. Por otra parte se continúa con la presentación de los alcances; como también la cobertura teórica y empírica de las variables siguientes: los servicios, tratamientos, costos, programas, problemas bucales y número de piezas cariadas, tratamientos que se deberían de realizar, etc. En cuanto a limitaciones son las dificultades que se encontraron en el desarrollo del trabajo. Las unidades de análisis fueron aquellas personas que asistieron a las clínicas estomatológicas, así como el personal odontológico, directores de salud, centros educativos, alcaldes, representante de la junta de vigilancia y director departamental del área de odontología. Se finaliza esta primera fase con la definición real de términos básicos. En la segunda fase se presenta el marco de referencia, en el cual se habla acerca de las condiciones socioeconómicas tanto del departamento de Usulután como de los municipios en estudio, su historia, las características demográficas, organizaciones religiosas, económicas de salud y asistencia social, otras organizaciones existentes, administración de la comunidad o municipio, sistema educativo y el marco general de la problemática estomatológica. La tercera fase se refiere a la metodología de la investigación en la cual se postula, primeramente el tipo de investigación, la cual se clasifica como diagnóstica ya que trata de describir los indicadores que se estudian cuyo propósito es obtener la información acerca del estado actual de la realidad socioestomatológica que se vive en El Salvador como resultado directo o indirecto con las fuentes de información, también se describe la población, la obtención de la muestra, submuestra y selección de los sujetos. La cuarta fase titulada resultado del diagnóstico contiene en primer lugar los cuadros estadísticos en el cual cada cuadro contiene los resultados obtenidos como también su respectiva descripción. Se presenta la discusión de los resultados de la investigación. Posteriormente en la cual en base a todos los resultados de la investigación, se hace una serie de análisis por municipios y general. Luego se presentan las conclusiones y recomendaciones dirigidas a las diferentes autoridades como son la junta de vigilancia de la profesión odontológica, el MSPAS, diferentes directores de unidades de salud, directores de las escuelas públicas y privadas por último se presenta tanto la bibliografía consultada como los anexos, que comprende la información utilizada en el trayecto de la investigación.

The present work consists of 4 phases. In the first phase of this work, the justification of the work is presented in the first place, which consists of the importance of carrying out this study as well as the usefulness of this research work, followed by the general objective in which it is proposed to carry out the diagnosis of the socio-stomatological reality of the municipalities under study; subsequently the specific objectives, the budget assigned by the MSPAS to the stomatological area is verified, the existence of a control by the surveillance board and the number of decayed, lost and filled pieces of the patients by strata attending the clinics is verified . On the other hand, the presentation of the scopes continues; as well as the theoretical and empirical coverage of the following variables: services, treatments, costs, programs, oral problems and number of decayed parts, treatments that should be performed, etc. As for limitations, they are the difficulties that were found in the development of the work. The units of analysis were those people who attended the stomatological clinics, as well as the dental staff, health directors, educational centers, mayors, representative of the surveillance board and departmental director of the area of ​​dentistry. This first phase is finished with the actual definition of basic terms. In the second phase, the frame of reference is presented, in which the socioeconomic conditions of both the department of Usulután and the municipalities under study are discussed, their history, demographic characteristics, religious organizations, economic health and social assistance, other existing organizations, administration of the community or municipality, educational system and the general framework of the stomatological problem. The third phase refers to the research methodology in which the type of research is postulated, first, which is classified as diagnostic since it tries to describe the indicators that are studied whose purpose is to obtain information about the current state of the socio-stomatological reality that is lived in El Salvador as a direct or indirect result with the sources of information, the population, the obtaining of the sample, subsample and selection of the subjects are also described. The fourth phase entitled diagnosis result contains first the statistical tables in which each table contains the results obtained as well as their respective description. The discussion of the research results is presented. Subsequently, in which, based on all the results of the investigation, a series of analyzes by municipalities and general is made. Then the conclusions and recommendations addressed to the different authorities are presented, such as the supervisory board of the dental profession, the MSPAS, different directors of health units, directors of public and private schools. Finally, both the consulted bibliography and the annexes, which include the information used in the investigation.