TY - JOUR
T1 - Model-Guided Design and Optimization of CPA Perfusion Protocols for Whole Organ Cryopreservation
AU - Han, Zonghu
AU - Rao, Joseph Sushil
AU - Ramesh, Srivasupradha
AU - Hergesell, Jan
AU - Namsrai, Bat Erdene
AU - Etheridge, Michael L.
AU - Finger, Erik B.
AU - Bischof, John C.
N1 - Funding Information:
This work was supported by NIH R01DK117425, NIH R01DK132211, NIH R01HL135046, NSF EEC 1941543, and a generous gift from the Biostasis Research Institute.
PY - 2023/10
Y1 - 2023/10
N2 - Vitrification could enable long-term organ preservation, but only after loading high-concentration, potentially toxic cryoprotective agents (CPAs) by perfusion. In this paper, we combine a two-compartment Krogh cylinder model with a toxicity cost function to theoretically optimize the loading of CPA (VMP) in rat kidneys as a model system. First, based on kidney perfusion experiments, we systematically derived the parameters for a CPA transport loading model, including the following: V b = 86.0% (r a = 3.86 μm), L p = 1.5 × 10–14 m3/(N·s), ω = 7.0 × 10–13 mol/(N·s), σ = 0.10. Next, we measured the toxicity cost function model parameters as α = 3.12 and β = 9.39 × 10–6. Combining these models, we developed an improved kidney-loading protocol predicted to achieve vitrification while minimizing toxicity. The optimized protocol resulted in shorter exposure (25 min or 18.5% less) than the gold standard kidney-loading protocol for VMP, which had been developed based on decades of empirical practice. After testing both protocols on rat kidneys, we found comparable physical and biological outcomes. While we did not dramatically reduce toxicity, we did reduce the time. As our approach is now validated, it can be used on other organs lacking defined toxicity data to reduce CPA exposure time and provide a rapid path toward developing CPA perfusion protocols for other organs and CPAs.
AB - Vitrification could enable long-term organ preservation, but only after loading high-concentration, potentially toxic cryoprotective agents (CPAs) by perfusion. In this paper, we combine a two-compartment Krogh cylinder model with a toxicity cost function to theoretically optimize the loading of CPA (VMP) in rat kidneys as a model system. First, based on kidney perfusion experiments, we systematically derived the parameters for a CPA transport loading model, including the following: V b = 86.0% (r a = 3.86 μm), L p = 1.5 × 10–14 m3/(N·s), ω = 7.0 × 10–13 mol/(N·s), σ = 0.10. Next, we measured the toxicity cost function model parameters as α = 3.12 and β = 9.39 × 10–6. Combining these models, we developed an improved kidney-loading protocol predicted to achieve vitrification while minimizing toxicity. The optimized protocol resulted in shorter exposure (25 min or 18.5% less) than the gold standard kidney-loading protocol for VMP, which had been developed based on decades of empirical practice. After testing both protocols on rat kidneys, we found comparable physical and biological outcomes. While we did not dramatically reduce toxicity, we did reduce the time. As our approach is now validated, it can be used on other organs lacking defined toxicity data to reduce CPA exposure time and provide a rapid path toward developing CPA perfusion protocols for other organs and CPAs.
KW - Cryoprotectant
KW - Organ perfusion optimization
KW - Organ vitrification
KW - Toxicity
KW - Transport
UR - http://www.scopus.com/inward/record.url?scp=85162709082&partnerID=8YFLogxK
U2 - 10.1007/s10439-023-03255-5
DO - 10.1007/s10439-023-03255-5
M3 - Article
C2 - 37351756
AN - SCOPUS:85162709082
SN - 0090-6964
VL - 51
SP - 2216
EP - 2228
JO - Annals of biomedical engineering
JF - Annals of biomedical engineering
IS - 10
ER -