The results indicated that there were good agreements betwee

The results indicated that there were good agreements between the proposed model predictions and literature experiment data, such that the overall average absolute deviation of gas hydrate formation pressures obtained was lower than 4.2%. Among the studied ionic liquids, the minimum amounts of AADP% were obtained for [OH-EMIM][BF4] and [EMIM][EtSO4] (below 1.3%), while the maximum value belonged to [BMIM][Br] (4.2%). Moreover, the AADPs calculated for the gas hydrate equilibrium conditions in the presence of [EMIM][EtSO4] and [BMIM][BF4], whose binary coefficients were completely tuned using VLE data, were obtained as about 1.25% and 1.66%, respectively. It can prove the prediction validity of the proposed model. Finally, the effect of concentration changes of [BMIM][BF4] was predicted satisfactorily using the model, such that the trends were predicted and the calculated AADPs were obtained below 2% for various amounts of [BMIM][BF4].
Introduction The ability to bank human tissues without compromising their viability is of paramount importance for transplantation and personalized medicine, translational research, biomarker discovery, and addressing the molecular basis of many diseases such as cancer. Tissue transplantation can be lifesaving (e.g., skin transplantation in severe burn cases) and/or life enhancing (e.g., replacing damaged ligaments) but suffers from a worldwide shortage of transplantable tissues according to the World Health Organization (WHO) [34]. Furthermore, the availability of diverse tissues cryobanked in a viable manner would enormously contribute to the emerging field of tissue engineering that also suffers from lack of a reliable cryopreservation method as identified by the Multi-Agency Tissue Engineering Science (MATES) [20]. Although some progress has been made in cryopreservation of certain tissues such as ovarian tissue and vein segments [33], [36] preservation of many 350 tissues and organs still remains challenging [15], [21], [35]. Typically, cryoprotective agents (CPAs) such as dimethylsulfoxide (Me2SO), ethylene glycol (EG), and propylene glycol (PG) must be present both intra- and extracellularly to facilitate successful cryopreservation of tissues. However, addition and removal of such penetrating CPAs before and after cryopreservation, respectively, are challenging due to associated osmotic stresses and chemical toxicity of CPAs. In fact, mitigation of the CPA induced toxicity has been highlighted as one of the critical impediments of tissue and organ cryopreservation [28]. Consequently, innovative approaches are required to overcome such challenges. The objective of the present study was to develop an approach to optimize CPA addition toward minimizing osmotic stresses and chemical toxicity of CPAs. Cryoprotectant equilibration and the response to ice concentrated media are the two facets of cellular cryobiological protocols most commonly covered by mathematical modeling. In these models, cells are typically assumed to have uniform, spatially independent extracellular concentrations and temperatures (see Ref. [3] for review). Spatial homogeneity and infinite bath media assumptions mean that ordinary differential equation models can be used to determine the intracellular state as a function of cryoprotocol. The transport equations typically used to describe the intracellular water volume W and moles of solute S as a function of time t:are known as the two-parameter (or 2P) equations in contrast with the three parameter Kedem-Ketchalsky model which is now less used in cryobiological literature (see Ref. [26] for explanation). Here LpRT and Ps are water and solute permeabilities respectively, A the cell surface area (assumed constant), C concentrations with superscript indicating extracellular or intracellular quantities (see Table 1 for a table of parameters). This model is coupled via a relationship between total cell volume and water volume known as the Boyle van\'t Hoff relationship [6].