A novel exopolysaccharide (p-CY01) from the Antarctic bacterium Pseudoalteromonas sp. strain CY01 cryopreserves human red blood cells

• Published in: Biomaterials science 2023-10, Vol.11 (21), p.7146-7157
• Main Authors: Kim, Sung Jin, Youn, Ui Joung, Kang, Pilsung, Kim, Tai Kyoung, Kim, Il-Chan, Han, Se Jong, Lee, Dong-Woo, Yim, Joung Han
• Format: Article
• Language: English
• Subjects: Biological materials; Cell membranes; Cryopreservation; Dimethyl sulfoxide; Erythrocytes; Galactose; Glycerol; Low concentrations; Low molecular weights; Molecular weight; Transplantation; Viscosity
• ISSN: 2047-4830; 2047-4849
• DOI: 10.1039/d3bm00917c

Cryopreservation of human red blood cells (RBCs) is vital for regenerative medicine and organ transplantation, but current cryoprotectants (CPAs) like glycerol and hydroxyethyl starch (HES) have limitations. Glycerol requires post-thaw washing due to cell membrane penetration, while HES causes high viscosity. To address these issues, we explored exopolysaccharides (EPS) from Antarctic Pseudoalteromonas sp. strain CY01 as a non-penetrating CPA for RBC cryopreservation. The EPS, p-CY01, consisted mainly of repeating (1–4) glucose and (1–6) galactose linkages with a molecular mass of 1.1 × 10 7 Da. Through mild acid hydrolysis, we obtained low molecular weight p-CY01 (p-CY01 LM) with a molecular weight of 2.7 × 10 5 Da, offering reduced viscosity, improved solubility, and cryoprotective properties. Notably, combining low concentrations of penetrating CPAs (>1% glycerol and dimethyl sulfoxide) with 2.5% (w/v) p-CY01 LM demonstrated significant cryoprotective effects. These findings highlight the potential of p-CY01 LM as a highly effective CPA for human RBC cryopreservation, replacing HES and glycerol and enabling the long-term storage of biological materials.