Dimethyl Sulfoxide-Free Cryopreservation of Human Umbilical Cord Mesenchymal Stem Cells Based on Zwitterionic Betaine and Electroporation

Expanding the cryoprotectant toolbox in biomedicine by multifunctional antifreeze peptides

The global cryopreservation market size rises exponentially due to increased demand for cell therapy-based products, assisted reproductive technology, and organ transplantation. Cryoprotectants (CPAs) are required to reduce ice-related damage, osmotic cell injury, and protein denaturation. Antioxidants are needed to hamper membrane lipid peroxidation under freezing stress, and antibiotics are added to the cryo-solutions to prevent contamination. The vitrification process for sized organs requires a high concentration of CPA, which is hardly achievable using conventional penetrating toxic CPAs like DMSO. Antifreeze peptides (AFpeps) are biocompatible CPAs leveraging inspiration from nature, such as freeze-tolerant and freeze-avoidant organisms, to circumvent logistic limitations in cryogenic conditions. This study aims to introduce the advances of AFpeps with cell-penetrating, antioxidant, and antimicrobial characteristics. We herein revisit the placement of AFpeps in the biobanking of cancer cells, immune cells, stem cells, blood cells, germ cells (sperms and oocytes), and probiotics. Implementing low-immunogenic AFpeps for allograft cryopreservation minimizes HLA mismatching risk after organ transplantation. Applying AFpeps to formulate bioinks with optimal rheology in extrusion-based 3D cryobiopriners expedites the bench-to-beside transition of bioprinted scaffolds. This study advocates that the fine-tuned synthetic or insect-derived AFpeps, forming round blunt-shape crystals, are biomedically broad-spectrum, and cell-permeable AFpeps from marine and plant sources, which result in sharp ice crystals, are appropriate for cryosurgery. Perspectives of the available room for developing peptide mimetics in favor of higher activity and stability and peptide-functionalized nanoparticles for enhanced delivery are delineated. Finally, antitumor immune activation by cryoimmunotherapy as an autologous in-vivo tumor lysate vaccine has been illustrated.

Targeting the tumor microenvironment with mesenchymal stem cells based delivery approach for efficient delivery of anticancer agents: An updated review

Drug delivery to cancer cells continues to present a major therapeutic challenge. Mesenchymal stem cells (MSCs) possess an intrinsic ability to migrate specifically to tumor tissues, making them promising candidates for targeted drug delivery. Evidence from preclinical studies indicates that MSCs loaded with therapeutic anti-cancer agents exhibit considerable anti-tumor activity. Moreover, several clinical trials are currently evaluating their effectiveness in cancer patients. The integration of MSCs with synthetic nanoparticles (NPs) enhances their therapeutic potential, particularly through the use of cell membrane-coated NPs, which represent a significant advancement in the field. This review systematically investigates the tumor microenvironment, the sources of MSCs, the tumor homing mechanisms, and the methods of loading and releasing anticancer drugs from MSCs. Furthermore, cutting-edge strategies to improve the efficacy of MSCs based drug delivery systems (DDS) including the innovative use of MSC membrane coated nanoparticles have been discussed. The study concludes with an overview of the therapeutic use of MSCs as drug carriers, including a detailed analysis of the mechanisms by which MSCs deliver therapeutics to cancer cells, enabling targeted drug delivery. It aims to elucidate the current state of this approach, identify key areas for development, and outline potential future directions for advancing MSCs based cancer therapies.

Automated Manufacturing Processes and Platforms for Large-scale Production of Clinical-grade Mesenchymal Stem/ Stromal Cells

Mesenchymal stem/stromal cells (MSCs) hold immense potential for regenerative medicine due to their remarkable regenerative and immunomodulatory properties. However, their therapeutic application requires large-scale production under stringent regulatory standards and Good Manufacturing Practice (GMP) guidelines, presenting significant challenges. This review comprehensively evaluates automated manufacturing processes and platforms for the scalable production of clinical-grade MSCs. Various large-scale culture vessels, including multilayer flasks and bioreactors, are analyzed for their efficacy in MSCs expansion. Furthermore, automated MSCs production platforms, such as Quantum® Cell Expansion System, CliniMACS Prodigy®, NANT001/ XL, CellQualia™, Cocoon® Platform, and Xuri™ Cell Expansion System W25 are reviewed and compared as well. We also underscore the importance of optimizing culture media specifically emphasizing the shift from fetal bovine serum to humanized or serum-free alternatives to meet GMP standards. Moreover, advances in alternative cryopreservation methods and controlled-rate freezing systems, that offer promising improvements in MSCs preservation, are discussed as well. In conclusion, advancing automated manufacturing processes and platforms is essential for realizing the full potential of MSCs-based regenerative medicine and accomplishing the increasing demand for cell-based therapies. Collaborative initiatives involving industry, academia, and regulatory bodies are emphasized to accelerate the translation of MSCs-based therapies into clinical practice.

Dimethyl-Sulfoxide-Free Cell Cryoprotectant Derived from Amino Acids

With the large-scale applications of cryopreservation technology in the cell therapy fields, traditional permeable cryoprotectants (CPAs) have led to serious issues, such as cell cycle arrest, inhibition of cell proliferation and differentiation, apoptosis, altered gene expression, etc. Development of green, non-toxic cryoprotectants is critically needed. Amino acids could serve as substrates for protein and cellular metabolism and as cryoprotectants with non-toxicity, balancing the intracellular water osmotic pressure. Current research on amino acids as cryoprotectants is hindered by several limitations, including unclear protection mechanisms, cryopreservation methods, and poor efficacy of individual formulations. Therefore, three specific amino acids and derivatives, including l-proline, l-carnitine, and betaine, as cryoprotectants were used for two types of cell cryopreservation. Single-factor experiments were conducted to obtain the optimal concentration range for each of the three amino acid cryoprotectants. On the basis of the key thermophysical parameters, the ability to inhibit ice crystals, and the effect after cryopreservation, multivariate orthogonal experiments were carried out to evaluate the actual effect of the three-component mixed cryoprotectant on cell cryopreservation. In comparison to the gold standard of 10% dimethyl sulfoxide (DMSO) for cell cryopreservation, the mixed cryoprotectant derived from amino acids achieves comparable preservation efficacy at lower concentrations with a convenient application method, which offers guidance for DMSO-free cryoprotectants.

A betaine-contained solution reduced cold ischemia damage through inhibiting vacuolar degeneration in livers

A new osmoprotectant-containing multiple saccharide (MS) solution was formulated for this study. The primary objectives were to compare the effects of the MS solution with those of the University of Wisconsin (UW) solution and hypertonic citrate adenine (HCA) solution on liver cold preservation, as well as to investigate the mechanisms underlying osmolarity-induced injury. Rat livers were cold-stored for 18 h at 4 °C using the different solutions and subsequently subjected to 2 h of normothermic machine perfusion (NMP) for functional assessment. The livers were categorized into four groups: HCA, UW, MS, and a control group. Liver function and histological changes were evaluated using biochemical markers such as lactate dehydrogenase (LDH), alongside histopathological analysis. Additionally, the expression of aquaporin 9 (AQP9) and hydrogen peroxide (H2O2) in hepatocytes was examined. Liver damage was significantly reduced in the UW and MS groups (p < 0.05). Histopathological analysis revealed a decrease in hepatic apoptosis and injury scores in the MS group compared to the HCA group (p < 0.05). No significant differences in liver function changes were observed between the MS and UW groups. Furthermore, examination of liver tissue showed increased H2O2 fluorescence intensity and decreased AQP9 protein levels in livers exhibiting vacuolar degeneration. In conclusion, the MS solution demonstrated superior effectiveness in preserving the liver during cold storage by inhibiting vacuolar degeneration caused by intracellular H2O2 accumulation.

Optimisation of cryopreservation conditions, including storage duration and revival methods, for the viability of human primary cells

BACKGROUND

Cryopreservation is a crucial procedure for safeguarding cells or other biological constructs, showcasing considerable potential for applications in tissue engineering and regenerative medicine.

AIMS

This study aimed to evaluate the effectiveness of different cryopreservation conditions on human cells viability.

METHODS

A set of cryopreserved data from Department of Tissue Engineering and Regenerative Medicine (DTERM) cell bank were analyse for cells attachment after 24 h being revived. The revived cells were analysed based on different cryopreservation conditions which includes cell types (skin keratinocytes and fibroblasts, respiratory epithelial, bone marrow mesenchymal stem cell (MSC); cryo mediums (FBS + 10% DMSO; commercial medium); storage durations (0 to > 24 months) and locations (tank 1-2; box 1-5), and revival methods (direct; indirect methods). Human dermal fibroblasts (HDF) were then cultured, cryopreserved in different cryo mediums (HPL + 10% DMSO; FBS + 10% DMSO; Cryostor) and stored for 1 and 3 months. The HDFs were revived using either direct or indirect method and cell number, viability and protein expression analysis were compared.

RESULTS

In the analysis cell cryopreserved data; fibroblast cells; FBS + 10% DMSO cryo medium; storage duration of 0-6 months; direct cell revival; storage in vapor phase of cryo tank; had the highest number of vials with optimal cell attachment after 24 h revived. HDFs cryopreserved in FBS + 10% DMSO for 1 and 3 months with both revival methods, showed optimal live cell numbers and viability above 80%, higher than other cryo medium groups. Morphologically, the fibroblasts were able to retain their phenotype with positive expression of Ki67 and Col-1. HDFs cryopreserved in FBS + 10% DMSO at 3 months showed significantly higher expression of Ki67 (97.3% ± 4.62) with the indirect revival method, while Col-1 expression (100%) was significantly higher at both 1 and 3 months compared to other groups.

CONCLUSION

In conclusion, fibroblasts were able to retain their characteristics after various cryopreservation conditions with a slight decrease in viability that may be due to the thermal-cycling effect. However, further investigation on the longer cryopreservation periods should be conducted for other types of cells and cryo mediums to achieve optimal cryopreservation outcomes.

Mesenchymal stromal cells derived from various tissues: Biological, clinical and cryopreservation aspects: Update from 2015 review

Mesenchymal stromal cells (MSCs) have become one of the most investigated and applied cells for cellular therapy and regenerative medicine. In this update of our review published in 2015, we show that studies continue to abound regarding the characterization of MSCs to distinguish them from other similar cell types, the discovery of new tissue sources of MSCs, and the confirmation of their properties and functions that render them suitable as a therapeutic. Because cryopreservation is widely recognized as the only technology that would enable the on-demand availability of MSCs, here we show that although the traditional method of cryopreserving cells by slow cooling in the presence of 10% dimethyl sulfoxide (Me2SO) continues to be used by many, several novel MSC cryopreservation approaches have emerged. As in our previous review, we conclude from these recent reports that viable and functional MSCs from diverse tissues can be recovered after cryopreservation using a variety of cryoprotectants, freezing protocols, storage temperatures, and periods of storage. We also show that for logistical reasons there are now more studies devoted to the cryopreservation of tissues from which MSCs are derived. A new topic included in this review covers the application in COVID-19 of MSCs arising from their immunomodulatory and antiviral properties. Due to the inherent heterogeneity in MSC populations from different sources there is still no standardized procedure for their isolation, identification, functional characterization, cryopreservation, and route of administration, and not likely to be a "one-size-fits-all" approach in their applications in cell-based therapy and regenerative medicine.

Mesenchymal stromal cells for improvement of cardiac function following acute myocardial infarction: a matter of timing

Acute myocardial infarction (AMI) is the leading cause of cardiovascular death and remains the most common cause of heart failure. Reopening of the occluded artery, i.e., reperfusion, is the only way to save the myocardium. However, the expected benefits of reducing infarct size are disappointing due to the reperfusion paradox, which also induces specific cell death. These ischemia-reperfusion (I/R) lesions can account for up to 50% of final infarct size, a major determinant for both mortality and the risk of heart failure (morbidity). In this review, we provide a detailed description of the cell death and inflammation mechanisms as features of I/R injury and cardioprotective strategies such as ischemic postconditioning as well as their underlying mechanisms. Due to their biological properties, the use of mesenchymal stromal/stem cells (MSCs) has been considered a potential therapeutic approach in AMI. Despite promising results and evidence of safety in preclinical studies using MSCs, the effects reported in clinical trials are not conclusive and even inconsistent. These discrepancies were attributed to many parameters such as donor age, in vitro culture, and storage time as well as injection time window after AMI, which alter MSC therapeutic properties. In the context of AMI, future directions will be to generate MSCs with enhanced properties to limit cell death in myocardial tissue and thereby reduce infarct size and improve the healing phase to increase postinfarct myocardial performance.