Cryopreservation as a Key Element in the Successful Delivery of Cell-Based Therapies-A Review

Drinking water elements constituent profiles and health risk assessment in Wuxi, China

Water elements pollution has attracted public attention globally. Wuxi is located in East China, and its water source, Taihu Lake, has been severely polluted since 2007. Studies of elemental pollution profiles have yet to be conducted in this area. In this study, 56 water samples were collected in 2018, and 33 elements were determined using inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the levels of 33 elements ranged from 1.35 × 10^-3 μg/L(Tl) to 101 mg/L(Ca), with Sr, Al, Fe, B, Ti, Ba, and Zn levels being relatively higher. A comprehensive literature review showed spatial distribution of conspicuous elements in drinking water worldwide. Meanwhile, Monte Carlo simulations were applied to evaluate exposure health risks. The total hazard index(HI) for 14 non-carcinogens and the average incremental lifetime cancer risk (ILCR) of As and Pb exposure through drinking water were found acceptable. Sensitivity analyses suggested that Sb and As in the drinking water represent an increasing risk to human health. The results of this study provide key data on local metal pollution characteristics, help identify potential risk factors, and contribute to the development of effective environmental management policies for Taihu Lake.

OUP accepted manuscript

Advances in regenerative medicine manufacturing continue to be a priority for achieving the full commercial potential of important breakthrough therapies. Equally important will be the establishment of distribution chains that support the transport of live cells and engineered tissues and organs resulting from these advanced biomanufacturing processes. The importance of a well-managed distribution chain for products requiring specialized handling procedures was highlighted during the COVID-19 pandemic and serves as a reminder of the critical role of logistics and distribution in the success of breakthrough therapies. This perspective article will provide insight into current practices and future considerations for creating global distribution chains that facilitate the successful deployment of regenerative medicine therapies to the vast number of patients that would benefit from them worldwide.

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

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.

The transfer temperature from slow cooling to cryogenic storage is critical for optimal recovery of cryopreserved mammalian cells

Cryopreservation is a key step for the effective delivery of many cell therapies and for the maintenance of biological materials for research. The preservation process must be carefully controlled to ensure maximum, post-thaw recovery using cooling rates slow enough to allow time for cells to cryodehydrate sufficiently to avoid lethal intracellular ice. This study focuses on determining the temperature necessary at the end of controlled slow cooling before transfer to cryogenic storage which ensures optimal recovery of the processed cell samples. Using nucleated, mammalian cell lines derived from liver (HepG2), ovary (CHO) and bone tissue (MG63) this study has shown that cooling must be controlled to -40°C before transfer to long term storage to ensure optimal cell recovery. No further advantage was seen by controlling cooling to lower temperatures. These results are consistent with collected differential scanning calorimetry data, that indicated the cells underwent an intracellular, colloidal glass transition between -49 and -59°C (Tg’i) in the presence of the cryoprotective agent dimethyl sulfoxide (DMSO). The glass forms at the point of maximum cryodehydration and no further cellular dehydration is possible. At this point the risk of lethal intracellular ice forming on transfer to ultra-low temperature storage is eliminated. In practice it may not be necessary to continue slow cooling to below this temperature as optimal recovery at -40°C indicates that the cells have become sufficiently dehydrated to avoid further, significant damage when transferred into ultra-low temperature storage.

Investigating the Solubility and Activity of a Novel Class of Ice Recrystallization Inhibitors

O-aryl-β-d-glucosides and N-alkyl-d-gluconamides are two classes of effective ice recrystallization inhibitors (IRIs), however their solubilities limit their use in cryopreservation applications. Herein, we have synthesized and assessed phosphonate analogues of small-molecule IRIs as a method to improve their chemical and physical properties. Four sodium phosphonate compounds 4–7 were synthesized and exhibited high solubilities greater than 200 mM. Their IRI activity was evaluated using the splat cooling assay and only the sodium phosphonate derivatives of α-methyl-d-glucoside (5-Na) and N-octyl-d-gluconamide (7-Na) exhibited an IC50 value less than 30 mM. It was found that the addition of a polar sodium phosphonate group to the alkyl gluconamide (1) and aryl glucoside (2) structure decreased its IRI activity, indicating the importance of a delicate hydrophobic/hydrophilic balance within these compounds. The evaluation of various cation-phosphonate pairs was studied and revealed the IRI activity of ammonium and its ability to modulate the IRI activity of its paired anion. A preliminary cytotoxicity study was also performed in a HepG2 cell line and phosphonate analogues were found to have relatively low cytotoxicity. As such, we present phosphonate small-molecule carbohydrates as a biocompatible novel class of IRIs with high solubilities and moderate-to-high IRI activities.

Advanced biomaterials in cell preservation: Hypothermic preservation and cryopreservation

Cell-based medicine has made great advances in clinical diagnosis and therapy for various refractory diseases, inducing a growing demand for cell preservation as support technology. However, the bottleneck problems in cell preservation include low efficiency and poor biocompatibility of traditional protectants. In this review, cell preservation technologies are categorized according to storage conditions: hypothermic preservation at 1 °C~35 °C to maintain short-term cell viability that is useful in cell diagnosis and transport, while cryopreservation at -196 °C~-80 °C to maintain long-term cell viability that provides opportunities for therapeutic cell product storage. Firstly, the background and developmental history of the protectants used in the two preservation technologies are briefly introduced. Secondly, the progress in different cellular protection mechanisms for advanced biomaterials are discussed in two preservation technologies. In hypothermic preservation, the hypothermia-induced and extracellular matrix-loss injuries to cells are comprehensively summarized, as well as the recent biomaterials dependent on regulation of cellular ATP level, stabilization of cellular membrane, balance of antioxidant defense system, and supply of mimetic ECM to prolong cell longevity are provided. In cryopreservation, cellular injuries and advanced biomaterials that can protect cells from osmotic or ice injury, and alleviate oxidative stress to allow cell survival are concluded. Last, an insight into the perspectives and challenges of this technology is provided. We envision advanced biocompatible materials for highly efficient cell preservation as critical in future developments and trends to support cell-based medicine. STATEMENT OF SIGNIFICANCE: Cell preservation technologies present a critical role in cell-based applications, and more efficient biocompatible protectants are highly required. This review categorizes cell preservation technologies into hypothermic preservation and cryopreservation according to their storage conditions, and comprehensively reviews the recently advanced biomaterials related. The background, development, and cellular protective mechanisms of these two preservation technologies are respectively introduced and summarized. Moreover, the differences, connections, individual demands of these two technologies are also provided and discussed.

Formulation Considerations for Autologous T Cell Drug Products

Genetically modified autologous T cells have become an established immunotherapy in the fight against cancer. The manufacture of chimeric antigen receptor (CAR) and αβ-T cell receptor (TCR) transduced T cells poses unique challenges, including the formulation, cryopreservation and fill-finish steps, which are the focus of this review. With an increasing number of marketing approvals for CAR-T cell therapies, comparison of their formulation design and presentation for administration can be made. These differences will be discussed alongside the emergence of automated formulation and fill-finish processes, the formulation design space, Monte Carlo simulation applied to risk analysis, primary container selection, freezing profiles and thaw and the use of dimethyl sulfoxide and alternative solvents/excipients as cryopreservation agents. The review will conclude with a discussion of the pharmaceutical solutions required to meet the simplification of manufacture and flexibility in dosage form for clinical treatment.

Brief Overview of Ice Nucleation

The nucleation of ice is vital in cloud physics and impacts on a broad range of matters from the cryopreservation of food, tissues, organs, and stem cells to the prevention of icing on aircraft wings, bridge cables, wind turbines, and other structures. Ice nucleation thus has broad implications in medicine, food engineering, mineralogy, biology, and other fields. Nowadays, the growing threat of global warming has led to intense research activities on the feasibility of artificially modifying clouds to shift the Earth’s radiation balance. For these reasons, nucleation of ice has been extensively studied over many decades and rightfully so. It is thus not quite possible to cover the whole subject of ice nucleation in a single review. Rather, this feature article provides a brief overview of ice nucleation that focuses on several major outstanding fundamental issues. The author’s wish is to aid early researchers in ice nucleation and those who wish to get into the field of ice nucleation from other disciplines by concisely summarizing the outstanding issues in this important field. Two unresolved challenges stood out from the review, namely the lack of a molecular-level picture of ice nucleation at an interface and the limitations of classical nucleation theory.