Showing papers by "Tuhin Subhra Santra published in 2020"
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TL;DR: The nanosecond-pulsed laser-activated plasmonic photoporation mediated by high-aspect-ratio nano-corrugated mushroom-shaped gold-coated polystyrene nanoparticles (nm-AuPNPs) at near-infrared wavelength has proven to have an inevitable potential for biological cell research and therapeutic applications.
Abstract: Here, an efficient intracellular delivery of molecules with high cell viability is reported using nanosecond-pulsed laser-activated plasmonic photoporation, mediated by high-aspect-ratio nano-corrugated mushroom-shaped gold-coated polystyrene nanoparticles (nm-AuPNPs) at near-infrared wavelength. Upon pulsed laser illumination, nm-AuPNPs exhibit greater plasmonic extinction than spherical AuPNPs, which increase their energy efficiency and reduce the necessary illumination of light, effectively controlling cell damage and improving the delivery efficiency. Nm-AuPNPs exhibit surface plasmon absorption at near infrared region with a peak at 945 nm. Pulsed laser illumination at this plasmon peak triggers explosive nanobubbles, which create transient membrane pores, allowing the delivery of dyes, quantum dots and plasmids into the different cell types. The results can be tuned by laser fluence, exposure time, molecular size and concentration of nm-AuPNPs. The best results are found for CL1-0 cells, which yielded a 94% intracellular PI dye uptake and ∼100% cell viability at 35 mJ cm−2 laser fluence for 945 nm wavelength. Thus, the presented approach has proven to have an inevitable potential for biological cell research and therapeutic applications.
35 citations
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TL;DR: This review highlights various single-neuron models and their behaviors, followed by different analysis methods, and emphasizes in detail the role of single-NEuron mapping and electrophysiological recording.
Abstract: The brain is an intricate network with complex organizational principles facilitating a concerted communication between single-neurons, distinct neuron populations, and remote brain areas The communication, technically referred to as connectivity, between single-neurons, is the center of many investigations aimed at elucidating pathophysiology, anatomical differences, and structural and functional features In comparison with bulk analysis, single-neuron analysis can provide precise information about neurons or even sub-neuron level electrophysiology, anatomical differences, pathophysiology, structural and functional features, in addition to their communications with other neurons, and can promote essential information to understand the brain and its activity This review highlights various single-neuron models and their behaviors, followed by different analysis methods Again, to elucidate cellular dynamics in terms of electrophysiology at the single-neuron level, we emphasize in detail the role of single-neuron mapping and electrophysiological recording We also elaborate on the recent development of single-neuron isolation, manipulation, and therapeutic progress using advanced micro/nanofluidic devices, as well as microinjection, electroporation, microelectrode array, optical transfection, optogenetic techniques Further, the development in the field of artificial intelligence in relation to single-neurons is highlighted The review concludes with between limitations and future prospects of single-neuron analyses
27 citations
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TL;DR: In infrared (IR) pulse laser-activated highly efficient parallel intracellular delivery by using an array of titanium microdish (TMD) device, which is compact, easy-to-use, and potentially applicable for cellular therapy and diagnostic purposes.
Abstract: We report infrared (IR) pulse laser-activated highly efficient parallel intracellular delivery by using an array of titanium microdish (TMD) device. Upon IR laser pulse irradiation, a two-dimensional array of TMD device generated photothermal cavitation bubbles to disrupt the cell membrane surface and create transient membrane pores to deliver biomolecules into cells by a simple diffusion process. We successfully delivered the dyes and different sizes of dextran in different cell types with variations of laser pulses. Our platform has the ability to transfect more than a million cells in a parallel fashion within a minute. The best results were achieved for SiHa cells with a delivery efficiency of 96% and a cell viability of around 98% for propidium iodide dye using 600 pulses, whereas a delivery efficiency of 98% and a cell viability of 100% were obtained for dextran 3000 MW delivery using 700 pulses. For dextran 10,000 MW, the delivery efficiency was 92% and the cell viability was 98%, respectively. The device is compact, easy-to-use, and potentially applicable for cellular therapy and diagnostic purposes.
22 citations
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TL;DR: The platform successfully delivers dyes, QDs, and plasmids into different cell types with the variation of field strength, pulse duration, and the number of pulses, which is potentially beneficial for cellular therapy and diagnostic purposes.
Abstract: The ability to deliver foreign cargos into single living cells is of great interest in cell biology and therapeutic research. Here, we have reported a single or multiple position based nano-localized single-cell nano-electroporation platform. The device consists of an array of triangular shape ITO nano-electrodes with a 70 nm gap between two nano-electrodes, each having a 40 nm tip diameter. The voltage is applied between nano-electrodes to generate an intense electric field, which electroporates multiple nano-localized regions of the targeted single-cell membrane, and biomolecules are gently delivered into cells by pressurizing pump flow, without affecting cell viability. The platform successfully delivers dyes, QDs, and plasmids into different cell types with the variation of field strength, pulse duration, and the number of pulses. This new approach allows us to analyze delivery of different biomolecules into single living cells with high transfection efficiency (>96%, for CL1-0 cells) and high cell viability (∼98%), which are potentially beneficial for cellular therapy and diagnostic purposes.
22 citations
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01 Jan 2020
TL;DR: This chapter mainly focuses on different physical drug-delivery techniques such as electroporation, optoporation, mechanopsoration, magnetoporation and hybrid techniques along with their working mechanisms, advantages, disadvantages, and limitations.
Abstract: Delivery of exogenous materials or cargo such as drugs, proteins, peptides, and nucleic acids into cells is a vital segment in molecular and cellular biology for potential cellular therapy and drug-discovery applications contributing toward personalization of medicine. Over the years, drug-delivery techniques have been developed in order to gain more control over the drug dosage, targeted delivery, and to minimize side effects. The major drug-delivery techniques can be classified as viral, chemical, and physical methods. Viral vectors are prominently used for gene therapy; however, they are cell-specific and have an immune response with high toxicity. Chemical methods are often limited by the low efficiency of plasmid delivery into different cell types due to plasmid degradation and toxicity. Considering these limitations, different physical methods such as photoporation, gene gun, hydrodynamic injection, electroporation, and mechanoporation, etc., are being widely developed for highly efficient cargo delivery with low toxicity. These methods are able to create transient hydrophilic membrane pores to deliver cargos into cells using different physical energies. Currently, ex vivo cargo delivery is widely studied while few in vivo applications have been developed. Concerning several obstacles to cargo delivery into cells, this chapter mainly focuses on different physical drug-delivery techniques such as electroporation, optoporation, mechanoporation, magnetoporation, and hybrid techniques along with their working mechanisms, advantages, disadvantages, and limitations. An insight into the future prospects and real-time applications of these techniques is also discussed.
18 citations
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TL;DR: The formed nanostructures were efficiently showed bone-like apatite formation followed by its gradual increase, when immersed in simulated body fluid (SBF) and it exhibited controlled degradation in 7 days.
Abstract: In the present work, we have investigated the formation of nanostructures on AZ31 magnesium alloy using electrochemical anodization technique. The formed nanostructures were efficiently showed bone-like apatite formation followed by its gradual increase, when immersed in simulated body fluid (SBF) and it exhibited controlled degradation in 7 days. Cell viability study was performed using MG-63 cells (human osteosarcoma cell lines) and revealed that the nanostructured surface has excellent biocompatibility by enhancing both cell adhesion and cell growth. The detailed characterization of this anodized surface was evaluated by field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDS). Furthermore, surface-corrosion before and after anodization was examined by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies in SBF. The in-depth studies bring out the fact that native oxide in the sample is converted to a biocompatible nanostructure, which is created due to anodization in a particular electrolyte solution containing ethylene glycol and hybrid hydrofluoric acid mixture.
12 citations
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01 Nov 2020
TL;DR: In this paper, the synthesis of different metal nanoparticles using microfluidic devices and their potential biomedical applications, such as sensing, imaging, and therapeutics and diagnostics, are discussed.
Abstract: Nanotechnology has shown promise in biomedical applications for diagnosis and treatment purposes. This chapter describes the synthesis of different metal nanoparticles using microfluidic devices and their potential biomedical applications, such as sensing, imaging, and therapeutics and diagnostics. Multiphase microfluidics is complex compared to single-phase microfluidics. Its design and function include interaction among various physiochemical phenomena, such as chemical reactions, heat and mass transport, and the hydrodynamics of fluid and the surface phenomenon. Continuous- (laminar) and segmented-flow types of microfluidic processes have been used to synthesize metallic nanoparticles, with their unique physical and chemical characteristics and controlled nano-structure. Biosensing is an important tool for early detection and sensing of medical parameters for healthcare applications. Optical properties of metallic nanoparticles provide many opportunities in biosensing. The chapter also elaborates the future challenges of nanoparticle preparation using microfluidic devices and their applications, advantages, and limitations.
9 citations
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TL;DR: Cells are known to be the most fundamental building block of life and mitochondria are the largest substance in the cell and are thought to be a major component of DNA.
Abstract: Cells are known to be the most fundamental building block of life[...].
8 citations
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TL;DR: This paper reports on the integration of a polydimethylsiloxane (PDMS) micronozzle array and bidirectional electrokinetic pumps driven by DC-biased AC voltages, which is anticipated to be a standard integration method.
Abstract: High throughput reconstruction of in vivo cellular environments allows for efficient investigation of cellular functions. If one-side-open multi-channel microdevices are integrated with micropumps, the devices will achieve higher throughput in the manipulation of single cells while maintaining flexibility and open accessibility. This paper reports on the integration of a polydimethylsiloxane (PDMS) micronozzle array and bidirectional electrokinetic pumps driven by DC-biased AC voltages. Pt/Ti and indium tin oxide (ITO) electrodes were used to study the effect of DC bias and peak-to-peak voltage and electrodes in a low conductivity isotonic solution. The flow was bidirectionally controlled by changing the DC bias. A pump integrated with a micronozzle array was used to transport single HeLa cells into nozzle holes. The application of DC-biased AC voltage (100 kHz, 10 Vpp, and VDC: -4 V) provided a sufficient electroosmotic flow outside the nozzle array. This integration method of nozzle and pumps is anticipated to be a standard integration method. The operating conditions of DC-biased AC electrokinetic pumps in a biological buffer was clarified and found useful for cell manipulation.
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01 Nov 2020
TL;DR: In this article, the authors discuss some of the prominent microfluidic strategies employed for cellular manipulation, analysis, and treatment and their feasibility in clinical applications, including electroporation and mechanoporation for single-cell therapeutic and diagnostic purposes.
Abstract: This chapter discusses in detail some of the prominent microfluidic strategies employed for cellular manipulation, analysis, and treatment and their feasibility in clinical applications. The major advantage of microfluidic techniques over other conventional methods is that they provide high-throughput devices for the manipulation and analysis of cells. Many high-throughput microfluidic devices have been used for single-cell trapping using electro-osmotic flow manipulation, microvortex manipulation, etc. The chapter discusses microfluidic-based physical techniques, such as electroporation and mechanoporation, for single-cell therapeutic and diagnostic purposes. Droplet microfluidics is frequently employed for single-cell analysis due to its high specificity and potentiality to isolate single cells. Additionally, microfluidic technologies are widely used to analyze single-cell intracellular components, such as DNA, RNA, proteins, and amino acids. Analysis of these components on a single-cell level is important due to the extreme variation in the composition of proteins within a population of cells.
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27 Sep 2020
TL;DR: It is demonstrated that Au NCs synthesized using a segmented flow-based microfluidic device can be used for the intracellular delivery of different exogenous molecules and potentially applicable to anisotropic AuNCs synthesis as well as cellular therapy and diagnostic purpose.
Abstract: This work presents the synthesis of anisotropic gold nanocrystals (Au NCs) using a segmented flow-based microfluidic device, and intracellular delivery using the synthesized particles. The device consists of T and Y shape junctions, cross channel, and winding geometries, where reagents mix. Reagents meet at the initial Y-junction and the T-shape junction generates droplets. Synthesized Au NCs are characterized and are found to possess multiple plasmonic peaks as per their size, shape and anisotropic nature. These plasmonic peaks can be tuned to the near-infrared region, which is advantageous in different biomedical applications. With the synthesized Au NCs as a mediator, propidium iodide dye is successfully delivered into the cellular cytoplasm of HeLa cells by using nanosecond pulse laser. The results demonstrated that Au NCs synthesized using a segmented flow-based microfluidic device can be used for the intracellular delivery of different exogenous molecules. The best results are achieved as 96% delivery efficiency and 98% cell viability. Thus, our platform potentially applicable to anisotropic Au NCs synthesis as well as cellular therapy and diagnostic purpose.
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01 Nov 2020
TL;DR: A comprehensive review of different types of microswimmers and microswimmer-based devices for biomedical and health care applications is provided in this paper, where the biomedical applications of micro-robots are divided into three categories: delivery, surgery, and sensing.
Abstract: Microfluidic platforms, lab-on-a-chip devices, and microswimmers of different kinds attract researchers for various biomedical applications. Microswimmers are now slowly changing many aspects of biomedical and health care sectors. This chapter provides a comprehensive review of different types of microswimmers and microswimmer-based devices for biomedical and health care applications. The mobile robots of microscale size and operated with the on-board approach are best suited for biomedical applications. The chapter discusses the different types of propulsion mechanisms and existing fabrication techniques for a micro-robot/microswimmer. The biomedical applications of micro-robots are divided into three categories: delivery, surgery, and sensing. The chapter describes these applications of micro-robots in detail. It also discusses the existing challenges and future potential of micro-robots and microswimmers. The challenges include precise and safe locomotion and targeting and minimizing the power consumption for sensing, locomotion, data transfer, and computation.
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01 Jan 2020
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27 Sep 2020TL;DR: The proposed device platform is an array of photothermal Micro-dish patterned with fibronectin protein to obtain specific Single-cell attachment and can deliver 10,000 individual cells with 97% efficiency and 95% cell viability simultaneously.
Abstract: Single-cell intracellular delivery is a booming field of interest with the various challenges faced due to the impermeability of cargo to the cell membrane barrier. The idea is to locally disrupt cell membrane for allowing cargo passage into the cytosol such as to create its therapeutic effect. Till to date, most of the intracellular delivery is performed in bulk approaches, which provides an average ensemble data, losing low-frequency rare information. Besides, reliable results require huge data from multiple cells. Hence, to ensure huge data on individual cells it becomes necessary to carry out delivery experiments on a large number of single-cells simultaneously. This ensures the same experimental conditions conserving heterogeneity in the cell population. The collection of data from individual cells provides information about rare low-frequency alleles in the cell population. Massively parallel delivery ensures such uniform experimental conditions with uniform cargo delivery to a large number of individual cells. The proposed device platform is an array of photothermal Micro-dish patterned with fibronectin protein to obtain specific Single-cell attachment. The device can deliver 10,000 individual cells with 97% efficiency and 95% cell viability simultaneously.