{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,26]],"date-time":"2026-06-26T23:43:13Z","timestamp":1782517393560,"version":"3.54.5"},"reference-count":37,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,3,30]],"date-time":"2023-03-30T00:00:00Z","timestamp":1680134400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["422444193"],"award-info":[{"award-number":["422444193"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biosensors"],"abstract":"<jats:p>The success rate in vitro fertilization is significantly linked to the quality of the oocytes. The oocyte\u2019s membrane is encapsulated by a shell of gelatinous extracellular matrix, called zona pellucida, which undergoes dynamic changes throughout the reproduction cycle. During the window of highest fertility, the zona pellucida exhibits a softening phase, while it remains rigid during oocyte maturation and again after fertilization. These variations in mechanical properties facilitate or inhibit sperm penetration. Since successful fertilization considerably depends on the state of the zona pellucida, monitoring of the hardening process of the zona pellucida is vital. In this study, we scrutinized two distinct genetic mouse models, namely, fetuin-B wild-type and fetuin-B\/ovastacin double deficient with normal and super-soft zona pellucida, respectively. We evaluated the hardening with the help of a microfluidic aspiration-assisted electrical impedance spectroscopy system. An oocyte was trapped by a microhole connected to a microfluidic channel by applying suction pressure. Transient electrical impedance spectra were taken by microelectrodes surrounding the microhole. The time-depending recovery of zona pellucida deflections to equilibrium was used to calculate the Young\u2019s modulus and, for the first time, absolute viscosity values. The values were obtained by fitting the curves with an equivalent mechanical circuit consisting of a network of dashpots and springs. The observer-independent electrical readout in combination with a fitting algorithm for the calculation of the viscoelastic properties demonstrates a step toward a more user-friendly and easy-to-use tool for the characterizing and better understanding of the rheological properties of oocytes.<\/jats:p>","DOI":"10.3390\/bios13040442","type":"journal-article","created":{"date-parts":[[2023,3,31]],"date-time":"2023-03-31T02:08:01Z","timestamp":1680228481000},"page":"442","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Viscoelastic Properties of Zona Pellucida of Oocytes Characterized by Transient Electrical Impedance Spectroscopy"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9840-8471","authenticated-orcid":false,"given":"Danyil","family":"Azarkh","sequence":"first","affiliation":[{"name":"Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstra\u00dfe 24, 52074 Aachen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2921-7513","authenticated-orcid":false,"given":"Yuan","family":"Cao","sequence":"additional","affiliation":[{"name":"Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstra\u00dfe 24, 52074 Aachen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julia","family":"Floehr","sequence":"additional","affiliation":[{"name":"Helmholtz-Institute for Biomedical Engineering, Biointerface Laboratory, RWTH Aachen University, Pauwelsstra\u00dfe 30, 52074 Aachen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2251-0605","authenticated-orcid":false,"given":"Uwe","family":"Schnakenberg","sequence":"additional","affiliation":[{"name":"Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstra\u00dfe 24, 52074 Aachen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2921","DOI":"10.1093\/humrep\/deab198","article-title":"International Committee for Monitoring Assisted Reproductive Technologies world report: Assisted reproductive technology, 2014","volume":"36","author":"Chambers","year":"2021","journal-title":"Hum. Reprod."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1186\/s13048-014-0111-5","article-title":"Oocyte zona pellucida dysmorphology is associated with diminished in-vitro fertilization success","volume":"8","author":"Vega","year":"2015","journal-title":"J. Ovarian Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1007\/BF02766828","article-title":"Zona pellucida thickness variation and occurrence of visible mononucleated blastomers in preembryos are associated with a high pregnancy rate in IVF treatment","volume":"15","author":"Palmstierna","year":"1998","journal-title":"J. Assist. Reprod. Genet."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1146\/annurev.bi.57.070188.002215","article-title":"Zona pellucida glycoproteins","volume":"57","author":"Wassarman","year":"1988","journal-title":"Annu. Rev. Biochem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1111\/j.1749-0774.2006.00019.x","article-title":"Mouse zona pellucida dynamically changes its elasticity during oocyte maturation, fertilization and early embryo development","volume":"19","author":"Murayama","year":"2006","journal-title":"Hum. Cell."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"S40","DOI":"10.1038\/nm-fertilityS41","article-title":"Genetic dissection of mammalian fertility pathways","volume":"8","author":"Matzuk","year":"2002","journal-title":"Nat. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1530\/rep.1.00530","article-title":"Deconstructing mammalian reproduction: Using knockouts to define fertility pathways","volume":"131","author":"Roy","year":"2006","journal-title":"Reproduction"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"520","DOI":"10.1038\/nature01262","article-title":"Initial sequencing and comparative analysis of the mouse genome","volume":"420","author":"Waterston","year":"2002","journal-title":"Nature"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Murayama, Y., Yoshida, K., Takahashi, H., Mizuno, J., Akaishi, K., and Inui, H. (2013, January 3\u20137). Softening of the mouse zona pellucida during oocyte maturation. Proceedings of the 2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Osaka, Japan.","DOI":"10.1109\/EMBC.2013.6611127"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1109\/TNB.2003.820273","article-title":"Mechanical property characterization of mouse zona pellucida","volume":"2","author":"Sun","year":"2003","journal-title":"IEEE Trans. Nanobiosci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1530\/REP-21-0122","article-title":"The E-modulus of the oocyte is a non-destructive measure of zona pellucida hardening","volume":"162","author":"Schmitz","year":"2021","journal-title":"Reproduction"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1007\/s00249-009-0468-3","article-title":"Mechanical properties of zona pellucida hardening","volume":"39","author":"Papi","year":"2010","journal-title":"Eur. Biophys. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"886","DOI":"10.1039\/c6ib00044d","article-title":"Investigating the mechanical properties of zona pellucida of whole human oocytes by atomic force spectroscopy","volume":"8","author":"Andolfi","year":"2016","journal-title":"Integr. Biol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2871","DOI":"10.1098\/rsif.2012.0269","article-title":"Nanoscale characterization of the biomechanical hardening of bovine zona pellucida","volume":"9","author":"Boccaccio","year":"2012","journal-title":"J. R. Soc. Interface"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"930","DOI":"10.1103\/PhysRevLett.56.930","article-title":"Atomic force microscope","volume":"56","author":"Binnig","year":"1986","journal-title":"Phys. Rev. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/S0021-9290(99)00175-X","article-title":"Micropipette aspiration of living cells","volume":"33","author":"Hochmuth","year":"2000","journal-title":"J. Biomech."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"587","DOI":"10.1016\/j.bpj.2019.01.004","article-title":"Advances in Micropipette Aspiration: Applications in Cell Biomechanics, Models, and Extended Studies","volume":"116","author":"Guinea","year":"2019","journal-title":"Biophys. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1007\/s00249-021-01587-5","article-title":"Micropipette-based biomechanical nanotools on living cells","volume":"51","author":"Wang","year":"2022","journal-title":"Eur. Biophys. J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1098\/rsif.2009.0380","article-title":"Estimating Young\u2019s modulus of zona pellucida by micropipette aspiration in combination with theoretical models of ovum","volume":"7","author":"Khalilian","year":"2010","journal-title":"J. R. Soc. Interface"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2623","DOI":"10.1039\/C8FO00149A","article-title":"Resveratrol reverses the adverse effects of a diet-induced obese murine model on oocyte quality and zona pellucida softening","volume":"9","author":"Jia","year":"2018","journal-title":"Food Funct."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1016\/j.ecoenv.2019.05.019","article-title":"Fluorene-9-bisphenol exposure induces cytotoxicity in mouse oocytes and causes ovarian damage","volume":"180","author":"Jia","year":"2019","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"111290","DOI":"10.1016\/j.ecoenv.2020.111290","article-title":"The toxic effects and possible mechanisms of decabromodiphenyl ethane on mouse oocyte","volume":"207","author":"Shi","year":"2021","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Cao, Y., Floehr, J., Ingebrandt, S., and Schnakenberg, U. (2021). Dry Film Resist Laminated Microfluidic System for Electrical Impedance Measurements. Micromachines, 12.","DOI":"10.3390\/mi12060632"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"133316","DOI":"10.1016\/j.snb.2023.133316","article-title":"Microfluidic aspiration-assisted electrical impedance spectroscopy system is a reliable tool for the characterization of oocyte hardening","volume":"380","author":"Cao","year":"2023","journal-title":"Sens. Actuators B Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1007\/s10008-005-0025-7","article-title":"Variable Mott-Schottky plots acquisition by potentiodynamic electrochemical impedance spectroscopy","volume":"9","author":"Bondarenko","year":"2005","journal-title":"J. Solid State Electrochem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1115\/1.1579047","article-title":"Alterations in the mechanical properties of the human chondrocyte pericellular matrix with osteoarthritis","volume":"125","author":"Alexopoulos","year":"2003","journal-title":"J. Biomech. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Cao, Y., Floehr, J., Yilmaz, E., Kremers, T., and Schnakenberg, U. (October, January 29). Microfluidic-Based Electrical Impedance Spectroscopy System Using Multilevel Lamination of Dry Film Photoresist. Proceedings of the 2021 International Workshop on Impedance Spectroscopy (IWIS), Chemnitz, Germany.","DOI":"10.1109\/IWIS54661.2021.9711851"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.devcel.2013.03.001","article-title":"Fetuin-B, a liver-derived plasma protein is essential for fertilization","volume":"25","author":"Dietzel","year":"2013","journal-title":"Dev. Cell."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1093\/molehr\/gaw068","article-title":"Down-regulation of the liver-derived plasma protein fetuin-B mediates reversible female infertility","volume":"23","author":"Floehr","year":"2017","journal-title":"Mol. Hum. Reprod."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"10809","DOI":"10.1038\/ncomms10809","article-title":"Human oocyte developmental potential is predicted by mechanical properties within hours after fertilization","volume":"7","author":"Yanez","year":"2016","journal-title":"Nat. Commun."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1191","DOI":"10.1007\/s10409-019-00895-6","article-title":"Viscoelastic models revisited: Characteristics and interconversion formulas for generalized Kelvin\u2013Voigt and Maxwell models","volume":"35","author":"Reyes","year":"2019","journal-title":"Acta Mech. Sin."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"218101","DOI":"10.1103\/PhysRevLett.104.218101","article-title":"Aspiration of biological viscoelastic drops","volume":"104","author":"Guevorkian","year":"2010","journal-title":"Phys. Rev. Lett."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1109\/TBME.2012.2230444","article-title":"Viscoelastic characterization of mouse zona pellucida","volume":"60","author":"Kim","year":"2013","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"14113","DOI":"10.1063\/1.3571530","article-title":"A microfluidic device for simultaneous electrical and mechanical measurements on single cells","volume":"5","author":"Chen","year":"2011","journal-title":"Biomicrofluidics"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3174","DOI":"10.1039\/c1lc20473d","article-title":"Classification of cell types using a microfluidic device for mechanical and electrical measurement on single cells","volume":"11","author":"Chen","year":"2011","journal-title":"Lab Chip"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2763","DOI":"10.3390\/s150202763","article-title":"Simultaneous characterization of instantaneous Young\u2019s modulus and specific membrane capacitance of single cells using a microfluidic system","volume":"15","author":"Zhao","year":"2015","journal-title":"Sensors"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3185","DOI":"10.1109\/TBME.2019.2901763","article-title":"Micropipette Aspiration of Single Cells for Both Mechanical and Electrical Characterization","volume":"66","author":"Pu","year":"2019","journal-title":"IEEE Trans. Biomed. Eng."}],"container-title":["Biosensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6374\/13\/4\/442\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:07:41Z","timestamp":1760123261000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6374\/13\/4\/442"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,3,30]]},"references-count":37,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2023,4]]}},"alternative-id":["bios13040442"],"URL":"https:\/\/doi.org\/10.3390\/bios13040442","relation":{},"ISSN":["2079-6374"],"issn-type":[{"value":"2079-6374","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,3,30]]}}}