Magnetic induction heating of superparamagnetic nanoparticles during rewarming augments the recovery of hUCM-MSCs cryopreserved by vitrification

Abstract

Cryopreservation by vitrification has been recognized as a promising strategy for long-term banking of living cells. However, the difficulty to generate a fast enough heating rate to minimize devitrification and recrystallization-induced intracellular ice formation during rewarming is one of the major obstacles to successful vitrification. We propose to overcome this hurdle by utilizing magnetic induction heating (MIH) of magnetic nanoparticles to enhance rewarming. In this study, superparamagnetic (SPM) Fe3O4 nanoparticles were synthesized by a chemical coprecipitation method. We successfully applied the MIH of Fe3O4 nanoparticles for rewarming human umbilical cord matrix mesenchymal stem cells (hUCM-MSCs) cryopreserved by vitrification. Our results show that extracellular Fe3O4 nanoparticles with MIH may greatly suppress devitrification and/or recrystallization during rewarming and significantly improve the survival of vitrified cells. We further optimized the concentration of Fe3O4 nanoparticles and the current of an alternating current (AC) magnetic field for generating the MIH to maximize cell viability. Our results indicate that MIH in an AC magnetic field with 0.05% (w/v) Fe3O4 nanoparticles significantly facilitates rewarming and improves the cryopreservation outcome of hUCM-MSCs by vitrification. The application of MIH of SPM nanoparticles to achieve rapid and spatially homogeneous heating is a promising strategy for enhanced cryopreservation of stem cells by vitrification.

Microfluidics for cryopreservation

“…For vitrification or low-CPA vitrification, cooling process is very simple compared to programmable slow freezing because the sample is directly immersed in liquid nitrogen for the fastest cooling available (Fahy, 1986b; Fahy et al, 1984; Huang et al, 2015; Wang et al, 2016) (Figure 1D (a)). Because no ice forms in either extra- or intracellular solution, no water or CPA transport across the cell membrane during freezing/thawing occurs (Fahy and Wowk, 2015) (Figure 1D (b).…”

“…Its extension form was further successfully used for the design of CPA equilibration for adherent endothelial cells (Davidson et al, 2015). Compared with programmed slow freezing, vitrification/low-CPA vitrification requires comparatively more CPA; therefore CPA addition and removal processes are more time consuming and costly (Choi et al, 2015a; Choi et al, 2015b; Huang et al, 2015; Wang et al, 2016). …”

“…Furthermore, the high surface-area-to-volume ratio of cell suspension on a chip intrinsically enables rapid cooling and warming needed for vitrification. More importantly, this technique provides an urgently needed method for preserving very limited volumes of biological samples, as often occurs with assisted reproductive technologies and stem cell research (Araki et al, 2015; Cohen and Garrisi, 1997; Cohen et al, 1997; Montag et al, 1998; Rao et al, 2015; Wang et al, 2016). Microfluidics can further be used to produce biological agents and cells in micro-scale volumes, enabling low-CPA droplet or encapsulation vitrification (Choi et al, 2015a; He et al, 2008; Huang et al, 2015; Risco et al, 2007; Tasoglu et al, 2013).…”

“…(D) Micrographs for typical cell volume responses. Reproduced from (Liu et al, 2015; Niu et al, 2015; Wang et al, 2016) with permission.…”

Isolation and Cryopreservation of Animal Mesenchymal Stromal Cells

“…This approach has been improved for the cryopreservation of organized tissues where even extracellular freezing causes several damages. In fact, in a recent study reported by Wang et al [53], magnetic induction heating of superparamagnetic nanoparticles was successfully applied to enhance rewarming, with promising results of the vitriied human umbilical cord matrix MSC survival.…”