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Yildirim RM, Seli E. Mitochondria as determinants of reproductive senescence and competence: implications for diagnosis of embryo competence in assisted reproduction. Hum Reprod 2024; 39:2160-2170. [PMID: 39066612 DOI: 10.1093/humrep/deae171] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 07/04/2024] [Indexed: 07/28/2024] Open
Abstract
Mitochondria are commonly recognized as the powerhouses of the cell, primarily responsible for energy production through oxidative phosphorylation. Alongside this vital function, they also play crucial roles in regulating calcium signaling, maintaining membrane potential, and modulating apoptosis. Their involvement in various cellular pathways becomes particularly evident during oogenesis and embryogenesis, where mitochondrial quantity, morphology, and distribution are tightly controlled. The efficiency of the mitochondrial network is maintained through multiple quality control mechanisms that are essential for reproductive success. These include mitochondrial unfolded protein response, mitochondrial dynamics, and mitophagy. Not surprisingly, mitochondrial dysfunction has been implicated in infertility and ovarian aging, prompting investigation into mitochondria as diagnostic and therapeutic targets in assisted reproduction. To date, mitochondrial DNA copy number in oocytes, cumulus cells, and trophectoderm biopsies, and fluorescent lifetime imaging microscopy-based assessment of NADH and flavin adenine dinucleotide content have been explored as potential predictors of embryo competence, yielding limited success. Despite challenges in the clinical application of mitochondrial diagnostic strategies, these enigmatic organelles have a significant impact on reproduction, and their potential role as diagnostic targets in assisted reproduction is likely to remain an active area of investigation in the foreseeable future.
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Affiliation(s)
- Raziye Melike Yildirim
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
| | - Emre Seli
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
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2
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Sánchez-Vargas J, Valdés-Parada FJ, Peraza-Reyes L, Lasseux D, Trujillo-Roldán MA. Flow modeling and structural characterization in fungal pellets. J Theor Biol 2024; 590:111853. [PMID: 38768893 DOI: 10.1016/j.jtbi.2024.111853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 04/11/2024] [Accepted: 05/14/2024] [Indexed: 05/22/2024]
Abstract
Fungal pellets are hierarchical systems that can be found in an ample variety of applications. Modeling transport phenomena in this type of systems is a challenging but necessary task to provide knowledge-based processes that improve the outcome of their biotechnological applications. In this work, an upscaled model for total mass and momentum transport in fungal pellets is implemented and analyzed, using elements of the volume averaging and adjoint homogenization methods departing from the governing equations at the microscale in the intracellular and extracellular phases. The biomass is assumed to be composed of a non-Newtonian fluid and the organelles impervious to momentum transport are modeled as a rigid solid phase. The upscaled equations contain effective-medium coefficients, which are predicted from the solution of adjoint closure problems in a three-dimensional periodic domains representative of the microstructure. The construction of these domains was performed for Laccaria trichodermophora based on observations of actual biological structures. The upscaled model was validated with direct numerical simulations in homogeneous portions of the pellets core. It is shown that no significant differences are observed when the dolipores are open or closed to fluid flow. By comparing the predictions of the average velocity in the extracellular phase resulting from the upscaled model with those from the classical Darcy equation (i.e., assuming that the biomass is a solid phase) the contribution of the intracellular fluid phase was evidenced. This work sets the foundations for further studies dedicated to transport phenomena in this type of systems.
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Affiliation(s)
- J Sánchez-Vargas
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, CDMX, Mexico; Posgrado en Ciencias Bioquímicas, Universidad Nacional Autónoma de México, 04510, CDMX, Mexico
| | - F J Valdés-Parada
- División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, 09340, CDMX, Mexico
| | - L Peraza-Reyes
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510, CDMX, Mexico
| | - D Lasseux
- University of Bordeaux, CNRS, Bordeaux INP, I2M, UMR 5295, Bordeaux, F-33400, Talence, France
| | - M A Trujillo-Roldán
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, CDMX, Mexico; Departamento de Bionanotecnología, Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, Baja California, Mexico.
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3
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Chaudhary K, Munjal P, Singh KP. Universal Stokes's nanomechanical viscometer. Sci Rep 2021; 11:14365. [PMID: 34257351 PMCID: PMC8277784 DOI: 10.1038/s41598-021-93729-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/25/2021] [Indexed: 11/26/2022] Open
Abstract
Although, many conventional approaches have been used to measure viscosity of fluids, most methods do not allow non-contact, rapid measurements on small sample volume and have universal applicability to all fluids. Here, we demonstrate a simple yet universal viscometer, as proposed by Stokes more than a century ago, exploiting damping of capillary waves generated electrically and probed optically with sub-nanoscale precision. Using a low electric field local actuation of fluids we generate quasi-monochromatic propagating capillary waves and employ a pair of single-lens based compact interferometers to measure attenuation of capillary waves in real-time. Our setup allows rapid measurement of viscosity of a wide variety of polar, non-polar, transparent, opaque, thin or thick fluids having viscosity values varying over four orders of magnitude from \documentclass[12pt]{minimal}
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\begin{document}$$10^{0}{-}10^{4}~\text{mPa} \, \text{s}$$\end{document}100-104mPas. Furthermore, we discuss two additional damping mechanisms for nanomechanical capillary waves caused by bottom friction and top nano-layer appearing in micro-litre droplets. Such self-stabilized droplets when coupled with precision interferometers form interesting microscopic platform for picomechanical optofluidics for fundamental, industrial and medical applications.
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Affiliation(s)
- Komal Chaudhary
- Department of Physical Sciences, Indian Institute of Science Education and Research, Mohali, Knowledge City, Sector 81, Manauli, 140306, India
| | - Pooja Munjal
- Department of Physical Sciences, Indian Institute of Science Education and Research, Mohali, Knowledge City, Sector 81, Manauli, 140306, India
| | - Kamal P Singh
- Department of Physical Sciences, Indian Institute of Science Education and Research, Mohali, Knowledge City, Sector 81, Manauli, 140306, India.
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4
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Huang Q, Chen B, Shen J, Liu L, Li J, Shi J, Li Q, Zuo X, Wang L, Fan C, Li J. Encoding Fluorescence Anisotropic Barcodes with DNA Fameworks. J Am Chem Soc 2021; 143:10735-10742. [PMID: 34242004 DOI: 10.1021/jacs.1c04942] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fluorescence anisotropy (FA) holds great potential for multiplexed analysis and imaging of biomolecules since it can effectively discriminate fluorophores with overlapping emission spectra. Nevertheless, its susceptibility to environmental variation hampers its widespread applications in biology and biotechnology. In this study, we design FA DNA frameworks (FAFs) by scaffolding fluorophores in a fluorescent protein-like microenvironment. We find that the FA stability of the fluorophores is remarkably improved due to the sequestration effects of FAFs. The FA level of the fluorophores can be finely tuned when placed at different locations on an FAF, analogous to spectral shifts of protein-bound fluorophores. The high programmability of FAFs further enables the design of a spectrum of encoded FA barcodes for multiplexed sensing of nucleic acids and multiplexed labeling of live cells. This FAF system thus establishes a new paradigm for designing multiplexing FA probes for cellular imaging and other biological applications.
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Affiliation(s)
- Qiuling Huang
- Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bin Chen
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acids Chemistry and Nanomedicine State Key Laboratory of Oncogenes and Related Genes, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Jianlei Shen
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lei Liu
- Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Jiajun Li
- Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Jiye Shi
- Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Qian Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaolei Zuo
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acids Chemistry and Nanomedicine State Key Laboratory of Oncogenes and Related Genes, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Lihua Wang
- The Interdisciplinary Research Center, Shanghai Synchrotron Radiation Facility, Zhangjiang Laboratory, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.,Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200127, China
| | - Chunhai Fan
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiang Li
- Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.,The Interdisciplinary Research Center, Shanghai Synchrotron Radiation Facility, Zhangjiang Laboratory, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
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5
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Kwapiszewska K, Szczepański K, Kalwarczyk T, Michalska B, Patalas-Krawczyk P, Szymański J, Andryszewski T, Iwan M, Duszyński J, Hołyst R. Nanoscale Viscosity of Cytoplasm Is Conserved in Human Cell Lines. J Phys Chem Lett 2020; 11:6914-6920. [PMID: 32787203 PMCID: PMC7450658 DOI: 10.1021/acs.jpclett.0c01748] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Metabolic reactions in living cells are limited by diffusion of reagents in the cytoplasm. Any attempt to quantify the kinetics of biochemical reactions in the cytosol should be preceded by careful measurements of the physical properties of the cellular interior. The cytoplasm is a complex, crowded fluid characterized by effective viscosity dependent on its structure at a nanoscopic length scale. In this work, we present and validate the model describing the cytoplasmic nanoviscosity, based on measurements in seven human cell lines, for nanoprobes ranging in diameters from 1 to 150 nm. Irrespective of cell line origin (epithelial-mesenchymal, cancerous-noncancerous, male-female, young-adult), we obtained a similar dependence of the viscosity on the size of the nanoprobes, with characteristic length-scales of 20 ± 11 nm (hydrodynamic radii of major crowders in the cytoplasm) and 4.6 ± 0.7 nm (radii of intercrowder gaps). Moreover, we revealed that the cytoplasm behaves as a liquid for length scales smaller than 100 nm and as a physical gel for larger length scales.
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Affiliation(s)
- Karina Kwapiszewska
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw, 01-224, Poland
| | - Krzysztof Szczepański
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw, 01-224, Poland
| | - Tomasz Kalwarczyk
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw, 01-224, Poland
| | - Bernadeta Michalska
- Nencki
Institute of Experimental Biology, Pasteura 3, Warsaw, 02-093, Poland
| | | | - Jędrzej Szymański
- Nencki
Institute of Experimental Biology, Pasteura 3, Warsaw, 02-093, Poland
| | - Tomasz Andryszewski
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw, 01-224, Poland
| | - Michalina Iwan
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw, 01-224, Poland
| | - Jerzy Duszyński
- Nencki
Institute of Experimental Biology, Pasteura 3, Warsaw, 02-093, Poland
| | - Robert Hołyst
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw, 01-224, Poland
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Sanchez T, Venturas M, Aghvami SA, Yang X, Fraden S, Sakkas D, Needleman DJ. Combined noninvasive metabolic and spindle imaging as potential tools for embryo and oocyte assessment. Hum Reprod 2019; 34:2349-2361. [PMID: 31812992 PMCID: PMC6936724 DOI: 10.1093/humrep/dez210] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 08/30/2019] [Accepted: 09/06/2019] [Indexed: 11/15/2022] Open
Abstract
STUDY QUESTION Is the combined use of fluorescence lifetime imaging microscopy (FLIM)-based metabolic imaging and second harmonic generation (SHG) spindle imaging a feasible and safe approach for noninvasive embryo assessment? SUMMARY ANSWER Metabolic imaging can sensitively detect meaningful metabolic changes in embryos, SHG produces high-quality images of spindles and the methods do not significantly impair embryo viability. WHAT IS KNOWN ALREADY Proper metabolism is essential for embryo viability. Metabolic imaging is a well-tested method for measuring metabolism of cells and tissues, but it is unclear if it is sensitive enough and safe enough for use in embryo assessment. STUDY DESIGN, SIZE, DURATION This study consisted of time-course experiments and control versus treatment experiments. We monitored the metabolism of 25 mouse oocytes with a noninvasive metabolic imaging system while exposing them to oxamate (cytoplasmic lactate dehydrogenase inhibitor) and rotenone (mitochondrial oxidative phosphorylation inhibitor) in series. Mouse embryos (n = 39) were measured every 2 h from the one-cell stage to blastocyst in order to characterize metabolic changes occurring during pre-implantation development. To assess the safety of FLIM illumination, n = 144 illuminated embryos were implanted into n = 12 mice, and n = 108 nonilluminated embryos were implanted into n = 9 mice. PARTICIPANTS/MATERIALS, SETTING, METHODS Experiments were performed in mouse embryos and oocytes. Samples were monitored with noninvasive, FLIM-based metabolic imaging of nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) autofluorescence. Between NADH cytoplasm, NADH mitochondria and FAD mitochondria, a single metabolic measurement produces up to 12 quantitative parameters for characterizing the metabolic state of an embryo. For safety experiments, live birth rates and pup weights (mean ± SEM) were used as endpoints. For all test conditions, the level of significance was set at P < 0.05. MAIN RESULTS AND THE ROLE OF CHANCE Measured FLIM parameters were highly sensitive to metabolic changes due to both metabolic perturbations and embryo development. For oocytes, metabolic parameter values were compared before and after exposure to oxamate and rotenone. The metabolic measurements provided a basis for complete separation of the data sets. For embryos, metabolic parameter values were compared between the first division and morula stages, morula and blastocyst and first division and blastocyst. The metabolic measurements again completely separated the data sets. Exposure of embryos to excessive illumination dosages (24 measurements) had no significant effect on live birth rate (5.1 ± 0.94 pups/mouse for illuminated group; 5.7 ± 1.74 pups/mouse for control group) or pup weights (1.88 ± 0.10 g for illuminated group; 1.89 ± 0.11 g for control group). LIMITATIONS, REASONS FOR CAUTION The study was performed using a mouse model, so conclusions concerning sensitivity and safety may not generalize to human embryos. A limitation of the live birth data is also that although cages were routinely monitored, we could not preclude that some runt pups may have been eaten. WIDER IMPLICATIONS OF THE FINDINGS Promising proof-of-concept results demonstrate that FLIM with SHG provide detailed biological information that may be valuable for the assessment of embryo and oocyte quality. Live birth experiments support the method's safety, arguing for further studies of the clinical utility of these techniques. STUDY FUNDING/COMPETING INTEREST(S) Supported by the Blavatnik Biomedical Accelerator Grant at Harvard University and by the Harvard Catalyst/The Harvard Clinical and Translational Science Center (National Institutes of Health Award UL1 TR001102), by NSF grants DMR-0820484 and PFI-TT-1827309 and by NIH grant R01HD092550-01. T.S. was supported by a National Science Foundation Postdoctoral Research Fellowship in Biology grant (1308878). S.F. and S.A. were supported by NSF MRSEC DMR-1420382. Becker and Hickl GmbH sponsored the research with the loaning of equipment for FLIM. T.S. and D.N. are cofounders and shareholders of LuminOva, Inc., and co-hold patents (US20150346100A1 and US20170039415A1) for metabolic imaging methods. D.S. is on the scientific advisory board for Cooper Surgical and has stock options with LuminOva, Inc.
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Affiliation(s)
- Tim Sanchez
- Department of Molecular and Cellular Biology and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
| | - Marta Venturas
- Department of Molecular and Cellular Biology and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
- Departament de Biologia Cellular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona
| | - S Ali Aghvami
- Department of Physics, Brandeis University, Waltham, MA, 02453
| | - Xingbo Yang
- Department of Molecular and Cellular Biology and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
| | - Seth Fraden
- Department of Physics, Brandeis University, Waltham, MA, 02453
| | - Denny Sakkas
- Boston IVF, 130 Second Avenue, Waltham, MA 02451
| | - Daniel J Needleman
- Department of Molecular and Cellular Biology and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
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8
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Novichkova NS, Malyan AN. The Effect of the Viscosity of a Trehalose Solution on ATP Hydrolysis by Chloroplast F1-ATPase. Biophysics (Nagoya-shi) 2019. [DOI: 10.1134/s0006350919060174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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9
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Chen E, Esquerra RM, Meléndez PA, Chandrasekaran SS, Kliger DS. Microviscosity in E. coli Cells from Time-Resolved Linear Dichroism Measurements. J Phys Chem B 2018; 122:11381-11389. [PMID: 30118225 DOI: 10.1021/acs.jpcb.8b07362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A protein's folding or function depends on its mobility through the viscous environment that is defined by the presence of macromolecules throughout the cell. The relevant parameter for this mobility is microviscosity-the viscosity on a time and distance scale that is important for protein folding/function movements. A quasi-null, ultrasensitive time-resolved linear dichroism (TRLD) spectroscopy is proving to be a useful tool for measurements of viscosity on this scale, with previous in vitro studies reporting on the microviscosities of crowded environments mimicked by high concentrations of different macromolecules. This study reports the microviscosity experienced by myoglobin in the E. coli cell's heterogeneous cytoplasm by using TRLD to measure rotational diffusion times. The results show that photolyzed deoxyMb ensembles randomize through environment-dependent rotational diffusion with a lifetime of 34 ± 6 ns. This value corresponds to a microviscosity of 2.82 ± 0.42 cP, which is consistent with previous reports of cytoplasmic viscosity in E. coli. The results of these TRLD studies in E. coli (1) provide a measurement of myoglobin mobility in the cytoplasm, (2) taken together with in vitro TRLD studies yield new insights into the nature of the cytoplasmic environment in cells, and (3) demonstrate the feasibility of TRLD as a probe of intracellular viscosity.
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Affiliation(s)
- Eefei Chen
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Raymond M Esquerra
- Department of Chemistry and Biochemistry , San Francisco State University , San Francisco , California 94132 , United States
| | - Philipp A Meléndez
- Department of Chemistry and Biochemistry , San Francisco State University , San Francisco , California 94132 , United States
| | - Sita S Chandrasekaran
- Department of Chemistry and Biochemistry , San Francisco State University , San Francisco , California 94132 , United States
| | - David S Kliger
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
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10
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Champagne PO, Westwick H, Bouthillier A, Sawan M. Colloidal stability of superparamagnetic iron oxide nanoparticles in the central nervous system: a review. Nanomedicine (Lond) 2018; 13:1385-1400. [DOI: 10.2217/nnm-2018-0021] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Superparamagnetic iron oxide nanoparticles (SPIONs) consist of nanosized metallic-based particles with unique magnetic properties. Their potential in both diagnostic and therapeutic applications in the CNS is at the source of an expanding body of the literature in recent years. Colloidal stability of nanoparticles represents their ability to resist aggregation and is a central aspect for the use of SPION in biological environment such as the CNS. This review gives a comprehensive update of the recent developments and knowledge on the determinants of colloidal stability of SPIONs in the CNS. Factors leading to aggregate formation and the repercussions of colloidal instability of SPION are reviewed in detail pertaining to their use in the CNS.
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Affiliation(s)
- Pierre-Olivier Champagne
- Polystim Neurotech Laboratory, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, H3T 1J4, Canada
- Department of Neurosurgery, University of Montreal Medical Center, Montreal, H2X 0C1, Canada
| | - Harrison Westwick
- Department of Neurosurgery, University of Montreal Medical Center, Montreal, H2X 0C1, Canada
| | - Alain Bouthillier
- Department of Neurosurgery, University of Montreal Medical Center, Montreal, H2X 0C1, Canada
| | - Mohamad Sawan
- Polystim Neurotech Laboratory, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, H3T 1J4, Canada
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11
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Sklodowska K, Debski PR, Michalski JA, Korczyk PM, Dolata M, Zajac M, Jakiela S. Simultaneous Measurement of Viscosity and Optical Density of Bacterial Growth and Death in a Microdroplet. MICROMACHINES 2018; 9:E251. [PMID: 30424184 PMCID: PMC6187717 DOI: 10.3390/mi9050251] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/17/2018] [Accepted: 05/18/2018] [Indexed: 02/07/2023]
Abstract
Herein, we describe a novel method for the assessment of droplet viscosity moving inside microfluidic channels. The method allows for the monitoring of the rate of the continuous growth of bacterial culture. It is based on the analysis of the hydrodynamic resistance of a droplet that is present in a microfluidic channel, which affects its motion. As a result, we were able to observe and quantify the change in the viscosity of the dispersed phase that is caused by the increasing population of interacting bacteria inside a size-limited system. The technique allows for finding the correlation between the viscosity of the medium with a bacterial culture and its optical density. These features, together with the high precision of the measurement, make our viscometer a promising tool for various experiments in the field of analytical chemistry and microbiology, where the rigorous control of the conditions of the reaction and the monitoring of the size of bacterial culture are vital.
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Affiliation(s)
- Karolina Sklodowska
- Department of Biophysics, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
- Department of Plant Genetics, Breeding and Biotechnology, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| | - Pawel R Debski
- Department of Biophysics, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| | - Jacek A Michalski
- Faculty of Civil Engineering, Mechanics and Petrochemistry, Warsaw University of Technology, 17 Lukasiewicza Street, 09400 Plock, Poland.
| | - Piotr M Korczyk
- Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawinskiego 5B, 02106 Warsaw, Poland.
| | - Miroslaw Dolata
- Department of Econophysics and Physics Application, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| | - Miroslaw Zajac
- Department of Biophysics, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
| | - Slawomir Jakiela
- Department of Biophysics, Warsaw University of Life Sciences, 159 Nowoursynowska Street, 02776 Warsaw, Poland.
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12
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Chen E, Kliger DS. Time-Resolved Linear Dichroism Measurements of Carbonmonoxy Myoglobin as a Probe of the Microviscosity in Crowded Environments. J Phys Chem B 2017; 121:7064-7074. [PMID: 28703591 DOI: 10.1021/acs.jpcb.7b04107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The distribution of viscosities in living cells is heterogeneous because of the different sizes and natures of macromolecular components. When thinking about protein folding/function processes in such an environment, the relevant (micro)viscosity at the micrometer length scale is necessarily distinguished from the bulk (macro)viscosity. The concentration dependencies of microviscosities are determined by a number of factors, such as electrostatic interactions, van der Waals forces, and excluded volume effects. To explore such factors, the rotational diffusion time of myoglobin in the presence of varying concentrations of macromolecules that differ in molecular weight (dextran 6000, 10 000, and 70 000), shape (dextran versus Ficoll), size, and surface charge is measured with time-resolved linear dichroism spectroscopy. The results of these studies offer simple empirically determined linear and exponential functions useful for predicting microviscosities as a function of concentration for these macromolecular crowders that are typically used to study crowding effects on protein folding. To understand how relevant these microviscosity measurements are to intracellular environments, the TRLD results are discussed in the context of studies that measure viscosity in cells.
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Affiliation(s)
- Eefei Chen
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
| | - David S Kliger
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
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13
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Dhakal K, Black B, Mohanty S. Introduction of impermeable actin-staining molecules to mammalian cells by optoporation. Sci Rep 2014; 4:6553. [PMID: 25315642 PMCID: PMC4197434 DOI: 10.1038/srep06553] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 09/02/2014] [Indexed: 12/21/2022] Open
Abstract
The selective insertion of foreign materials, such as fluorescent markers or plasmids, into living cells has been a challenging problem in cell biology due to the cell membrane's selective permeability. However, it is often necessary that researchers insert such materials into cells for various dynamical and/or drug delivery studies. This problem becomes even more challenging if the study is to be limited to specific cells within a larger population, since other transfection methods, such as viral transfection and lipofection, are not realizable with a high degree of spatial selectivity. Here, we have used a focused femtosecond laser beam to create a small transient hole in the cellular membrane (optoporation) in order to inject nanomolar concentrations of rhodamine phalloidin (an impermeable dye molecule for staining filamentous actin) into targeted living mammalian cells (both HEK and primary cortical neurons). Following optoporation, the dye bound to the intracellular actin network and rise in fluorescence intensity was observed. Theoretical dynamics of the dye's diffusion is discussed, and numerical simulations of diffusion time constants are found to match well with experimental values.
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Affiliation(s)
- Kamal Dhakal
- Biophysics and Physiology Lab, Department of Physics, University of Texas at Arlington, Texas, USA
| | - Bryan Black
- Biophysics and Physiology Lab, Department of Physics, University of Texas at Arlington, Texas, USA
| | - Samarendra Mohanty
- Biophysics and Physiology Lab, Department of Physics, University of Texas at Arlington, Texas, USA
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14
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Guet D, Mandal K, Pinot M, Hoffmann J, Abidine Y, Sigaut W, Bardin S, Schauer K, Goud B, Manneville JB. Mechanical role of actin dynamics in the rheology of the Golgi complex and in Golgi-associated trafficking events. Curr Biol 2014; 24:1700-11. [PMID: 25042587 DOI: 10.1016/j.cub.2014.06.048] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/06/2014] [Accepted: 06/18/2014] [Indexed: 01/08/2023]
Abstract
BACKGROUND In vitro studies have shown that physical parameters, such as membrane curvature, tension, and composition, influence the budding and fission of transport intermediates. Endocytosis in living cells also appears to be regulated by the mechanical load experienced by the plasma membrane. In contrast, how these parameters affect intracellular membrane trafficking in living cells is not known. To address this question, we investigate here the impact of a mechanical stress on the organization of the Golgi complex and on the formation of transport intermediates from the Golgi complex. RESULTS Using confocal microscopy, we visualize the deformation of Rab6-positive Golgi membranes applied by an internalized microsphere trapped in optical tweezers and simultaneously measure the corresponding forces. Our results show that the force necessary to deform Golgi membranes drops when actin dynamics is altered and correlates with myosin II activity. We also show that the applied stress has a long-range effect on Golgi membranes, perturbs the dynamics of Golgi-associated actin, and induces a sharp decrease in the formation of Rab6-positive vesicles from the Golgi complex as well as tubulation of Golgi membranes. CONCLUSIONS We suggest that acto-myosin contractility strongly contributes to the local rigidity of the Golgi complex and regulates the mechanics of the Golgi complex to control intracellular membrane trafficking.
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Affiliation(s)
- David Guet
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Kalpana Mandal
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Mathieu Pinot
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Jessica Hoffmann
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Yara Abidine
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Walter Sigaut
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Sabine Bardin
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Kristine Schauer
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Bruno Goud
- CNRS-Institut Curie, UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
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15
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Zhang Y, Wu X, Wang Y, Zhu S, Gao BZ, Yuan XC. Measurement of the microscopic viscosities of microfluids with a dynamic optical tweezers system. LASER PHYSICS 2014; 24:065601. [PMID: 27087769 PMCID: PMC4831734 DOI: 10.1088/1054-660x/24/6/065601] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Viscosity coefficients of microfluids-Newtonian and non-Newtonian-were explored through the rotational motion of a particle trapped by optical tweezers in a microflute. Unlike conventional methods based on viscometers, our microfluidic system employs samples of less than 30 µl to complete a measurement. Viscosity coefficients of ethanol and fetal bovine serum, as typical examples of Newtonian and non-Newtonian fluids, were obtained experimentally, and found to be in excellent agreement with theoretical predictions. Additionally, a practical application to a DNA solution with incremental ethidium bromide content was employed and the results are consistent with clinical data, indicating that our system provides a potentially important complementary tool for use in such biological and medical applications.
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Affiliation(s)
- Yuquan Zhang
- Institute of Modern Optics, Key Laboratory of Optoelectronic Information Science and Technology, Ministry of Education of China, Nankai University, Tianjin 300071, People's Republic of China
| | - Xiaojing Wu
- Nankai University Affiliated Hospital, Tianjin 300121, People's Republic of China
| | - Yijia Wang
- Institute of Modern Optics, Key Laboratory of Optoelectronic Information Science and Technology, Ministry of Education of China, Nankai University, Tianjin 300071, People's Republic of China
| | - Siwei Zhu
- Nankai University Affiliated Hospital, Tianjin 300121, People's Republic of China
| | - Bruce Z Gao
- Department of Bioengineering, Clemson University, Clemson, SC 29634, USA
| | - X-C Yuan
- Institute of Micro & Nano Optics, Shenzhen University, Shenzhen 518060, People's Republic of China
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