Current Approaches of Preservation of Cells During (freeze-) Drying

Rockinger, Ute; Funk, Martin; Winter, Gerhard

doi:10.1016/j.xphs.2021.04.018

Cited by 35 publications

(21 citation statements)

References 137 publications

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“…The protection of higher plant cells from the consequences of prolonged dehydration with the help of oligo-and polysaccharides represents a prominent example of the stabilizing effect exerted by sugars on biological membranes [1][2][3]. Simple carbohydrates represent one of the major protecting excipients in preservation of cells during freeze-drying [4]. The cryoprotective efficiency of sugars is related to the molecular mechanisms of their interaction with lipid membranes.…”

Section: Introductionmentioning

confidence: 99%

Dielectric Properties of Phosphatidylcholine Membranes and the Effect of Sugars

et al. 2021

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Simple carbohydrates are associated with the enhanced risk of cardiovascular disease and adverse changes in lipoproteins in the organism. Conversely, sugars are known to exert a stabilizing effect on biological membranes, and this effect is widely exploited in medicine and industry for cryopreservation of tissues and materials. In view of elucidating molecular mechanisms involved in the interaction of mono- and disaccharides with biomimetic lipid systems, we study the alteration of dielectric properties, the degree of hydration, and the rotational order parameter and dipole potential of lipid bilayers in the presence of sugars. Frequency-dependent deformation of cell-size unilamellar lipid vesicles in alternating electric fields and fast Fourier transform electrochemical impedance spectroscopy are applied to measure the specific capacitance of phosphatidylcholine lipid bilayers in sucrose, glucose and fructose aqueous solutions. Alteration of membrane specific capacitance is reported in sucrose solutions, while preservation of membrane dielectric properties is established in the presence of glucose and fructose. We address the effect of sugars on the hydration and the rotational order parameter for 1-palmitoyl-2-oleoyl-sn-glycero-3- phosphocholine (POPC) and 1-stearoyl-2-oleoyl-sn-glycero-3- phosphocholine (SOPC). An increased degree of lipid packing is reported in sucrose solutions. The obtained results provide evidence that some small carbohydrates are able to change membrane dielectric properties, structure, and order related to membrane homeostasis. The reported data are also relevant to future developments based on the response of lipid bilayers to external physical stimuli such as electric fields and temperature changes.

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Section: Introductionmentioning

confidence: 99%

Dielectric Properties of Phosphatidylcholine Membranes and the Effect of Sugars

et al. 2021

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“…There have been similar findings in studies of other vaccines but also in studies of monoclonal antibodies and other protein-based products [35][36][37][38]. Additionally, the freezing rate is considered very important when freezing cell-based products such as microorganisms or mammalian-cell-based therapeutics, which are classes of products that are expected to become increasingly important in medicine [39][40][41][42][43].…”

Section: Imposed Cooling Profilementioning

confidence: 67%

Development and Application of a Mechanistic Cooling and Freezing Model of the Spin Freezing Step within the Framework of Continuous Freeze-Drying

et al. 2021

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During the spin freezing step of a recently developed continuous spin freeze-drying technology, glass vials are rapidly spun along their longitudinal axis. The aqueous drug formulation subsequently spreads over the inner vial wall, while a cold gas flow is used for cooling and freezing the product. In this work, a mechanistic model was developed describing the energy transfer during each phase of spin freezing in order to predict the vial and product temperature change over time. The uncertainty in the model input parameters was included via uncertainty analysis, while global sensitivity analysis was used to assign the uncertainty in the model output to the different sources of uncertainty in the model input. The model was verified, and the prediction interval corresponded to the vial temperature profiles obtained from experimental data, within the limits of the uncertainty interval. The uncertainty in the model prediction was mainly explained (>96% of uncertainty) by the uncertainty in the heat transfer coefficient, the gas temperature measurement, and the equilibrium temperature. The developed model was also applied in order to set and control a desired vial temperature profile during spin freezing. Applying this model in-line to a continuous freeze-drying process may alleviate some of the disadvantages related to batch freeze-drying, where control over the freezing step is generally poor.

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“…Parameters such as drying method, freezing rate, cell density, residual moisture level, rehydration procedure can affect the cell survival during and after lyophilization. Therefore, to achieve maximum cell survival rates it is important to load trehalose intracellularly ( Rockinger et al., 2021 ).…”

Section: Applications Of Freeze-drying and Case Studies Of Freeze-dri...mentioning

confidence: 99%