Hemoglobin polymerized with a naturally occurring crosslinking agent as a blood substitute: in vitro and in vivo studies.
A naturally occurring crosslinking agent, genipin, extracted from the fruits of Gardenia jasminoides ELLIS was used by our group to chemically modified biomolecules. Genipin and its related iridoid glucosides have been widely used as an antiphlogistic and cholagogue in herbal medicine. Our previous study showed that the cytotoxicity of genipin is significantly lower than glutaraldehyde. The study was to investigate the feasibility of using genipin to polymerize hemoglobin as a blood substitute. The results indicated that the rate of hemoglobin polymerization by glutaraldehyde was significantly faster than that by genipin and it readily produced polymers with molecular masses greater than 500,000 Da. It was found that the maximum degree of hemoglobin polymerization by genipin was approximately 40% if over-polymerization is to be prevented. With increasing the reaction temperature, hemoglobin concentration, and genipin-to-hemoglobin molar ratio, the duration taken to achieve the maximum degree of hemoglobin polymerization by genipin became significantly shorter. The P50 value of the unmodified hemoglobin was 9 mmHg, while that of the genipin-polymerized PLP-hemoglobin increased to 21 mmHg. It was found in a rat model that the genipin-polymerized PLP-hemoglobin resulted in a longer circulation time than the unmodified hemoglobin. In conclusion, the results of the study indicated that the genipin-polymerized hemoglobin solution has a lower oxygen affinity and a longer vascular retention time than the unmodified hemoglobin solution.
Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan, ROC.
Wen-Hsiang
WH
Chang
Yen
Y
Chang
Yi-Chien
YC
Chen
Hsing-Wen
HW
Sung
D000818:Animals; D001704:Biopolymers / Q000737:chemistry / Q000494:pharmacology; D001802:Blood Substitutes / Q000737:chemistry* / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000494:pharmacology*; D005078:Exchange Transfusion, Whole Blood; D005998:Glycine / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry* / Q000187:drug effects / Q000494:pharmacology; D057889:Iridoid Glycosides; D039823:Iridoids; D008297:Male; D008706:Methemoglobin / Q000737:chemistry; D015394:Molecular Structure; D011714:Pyrans / Q000737:chemistry / Q000494:pharmacology*; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012822:Silicon Dioxide / Q000737:chemistry; D013552:Swine
D001704:Biopolymers; D001802:Blood Substitutes; D003432:Cross-Linking Reagents; D006454:Hemoglobins; D057889:Iridoid Glycosides; D039823:Iridoids; D011714:Pyrans; C016484:hemoglobin, stroma free; C030939:polyhemoglobin-pyridoxal-5-phosphate; D011732:Pyridoxal Phosphate; D012822:Silicon Dioxide; C049273:TSK-Gel G 3000SW; D008706:Methemoglobin; C007834:genipin; D005998:Glycine