Blood Products/Recombinant Blood Proteins
03/06/2024There are many types of blood products, with common products including human albumin and hemoglobin.
Albumin is a crucial blood protein, with the concentration reaching 35-55 g/L in plasma, accounting for 60% of total plasma protein. Human serum albumin (HSA) is synthesized by hepatocytes and is a single-chain polypeptide containing 585 amino acid residues, with a molecular weight of 66.4 kDa. The molecule includes 17 pairs of disulfide bonds, one free thiol group, and is non-glycosylated. HSA plays an irreplaceable role in cell culture, drug preparation, acting as a drug carrier, and clinical treatments.
HSA is sourced from plasma extraction and recombinant expression. Plasma extraction involves low-temperature centrifugation or cold ethanol precipitation to improve initial purity, followed by ultrafiltration, ion exchange, heparin affinity, molecular sieving, and pasteurization to achieve high-purity human albumin.
Erythropoietin (EPO) is a hormone secreted by the kidneys. Its main function is to stimulate the proliferation, differentiation, and maturation of erythrocyte precursor cells in the bone marrow, thereby increasing erythrocyte production. In the medical field, EPO is used to treat various diseases related to erythropoiesis, such as chronic renal anemia and anemia caused by cancer chemotherapy. The production of EPO can be achieved through genetic engineering. Typically using CHO cells as a matrix, and then clarifying and ultrafiltering the cell supernatant, followed by Blue Beads 6FF affinity chromatography, Q Beads 6FF or DEAE Beads 6FF chromatography, and finally molecular sieve chromatography to obtain high-purity EPO.
To further improve the quality of the final product, RP reverse-phase chromatography can be used instead of molecular sieve chromatography. This allows for precise separation of glycosylation modifications, resulting in higher specific activity, though it significantly increases purification costs.
