Publications by authors named "Nebras Sobahi"

2 Publications

  • Page 1 of 1

Effects of electrically conductive nano-biomaterials on regulating cardiomyocyte behavior for cardiac repair and regeneration.

Acta Biomater 2021 Nov 21. Epub 2021 Nov 21.

Division of Engineering in Medicine, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Cambridge, MA 02139, USA. Electronic address:

Myocardial infarction (MI) represents one of the most prevalent cardiovascular diseases, with a highly relevant and impactful role in public health. Despite the therapeutic advances of the last decades, MI still begets extensive death rates around the world. The pathophysiology of the disease correlates with cardiomyocyte necrosis, caused by an imbalance in the demand of oxygen to cardiac tissues, resulting from obstruction of the coronary flow. To alleviate the severe effects of MI, the use of various biomaterials exhibit vast potential in cardiac repair and regeneration, acting as native extracellular matrices. These hydrogels have been combined with nano sized or functional materials which possess unique electrical, mechanical, and topographical properties that play important roles in regulating phenotypes and the contractile function of cardiomyocytes even in adverse microenvironments. These nano-biomaterials' differential properties have led to substantial healing on in vivo cardiac injury models by promoting fibrotic scar reduction, hemodynamic function preservation, and benign cardiac remodeling. In this review, we discuss the interplay of the unique physical properties of electrically conductive nano-biomaterials, are able to manipulate the phenotypes and the electrophysiological behavior of cardiomyocytes in vitro, and can enhance heart regeneration in vivo. Consequently, the understanding of the decisive roles of the nano-biomaterials discussed in this review could be useful for designing novel nano-biomaterials in future research for cardiac tissue engineering and regeneration. STATEMENT OF SIGNIFICANCE: This study introduced and deciphered the understanding of the role of multimodal cues in recent advances of electrically conductive nano-biomaterials on cardiac tissue engineering. Compared with other review papers, which mainly describe these studies based on various types of electrically conductive nano-biomaterials, in this review paper we mainly discussed the interplay of the unique physical properties (electrical conductivity, mechanical properties, and topography) of electrically conductive nano-biomaterials, which would allow them to manipulate phenotypes and the electrophysiological behaviour of cardiomyocytes in vitro and to enhance heart regeneration in vivo. Consequently, understanding the decisive roles of the nano-biomaterials discussed in the review could help design novel nano-biomaterials in future research for cardiac tissue engineering and regeneration.
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http://dx.doi.org/10.1016/j.actbio.2021.11.022DOI Listing
November 2021

High-throughput and label-free multi-outlet cell counting using a single pair of impedance electrodes.

Biosens Bioelectron 2020 Oct 17;166:112458. Epub 2020 Jul 17.

Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA; Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA; Center for Remote Health Technologies and Systems Texas A&M University, College Station, TX, USA. Electronic address:

There are increasing number of cell separation applications where cells needs to be separated into multiple outlets. Quantification of sorted or separated cells and particles in microfluidic systems flowing through multiple outlet channels are typically conducted off-line through microscopic image analysis, or by first collecting cells from each outlet and counting them afterwards. However, these methods do not provide real-time analysis, are time consuming, and can lead to significant error in analysis when handling and collecting a small number of cells (such as rare cells). Here, we present a low-cost, label-free, and real-time on-chip cell counting and quantifying method for sorted/separated cells flowing through multiple microfluidic outlets using only a single pair of microelectrodes. The single staircase-shaped electrode design positioned perpendicular to the outlets subjects cells flowing through different outlets to different electric field strength, thus resulting in different impedance signals depending on which outlets the cell passes through. This design was enhanced by studying and comparing the results of both simulations and experiments. To analyze whether cells passing through each of the five outlets can be correctly classified based on their impedance peak height and width, three different classification methods were tested and compared. The developed design was successfully utilized to distinguish cells flowing through 5 different outlets using only a single pair of impedance electrodes, showing classification error rate of only 1.91%. This single-pair staircase-shaped electrode design can be applied to any cell separation system, regardless of the separation methods utilized, and thus have extremely broad application space in the field of microfluidic cell separation.
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http://dx.doi.org/10.1016/j.bios.2020.112458DOI Listing
October 2020
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