Controlled Polymerization and Ultrafiltration Increase the Consistency of Polymerized Hemoglobin for Use as an Oxygen Carrier

Abstract Background: Hemoglobin-based oxygen carriers can cause profound interferences in many analytical procedures. We determined the mechanism of interference in the assay of alkaline phosphatase activity and identified approaches that might be used to correct for this interference. Methods: Interference of a polymerized hemoglobin blood substitute with the assay of alkaline phosphatase was examined with a Hitachi 917 analyzer and ultraviolet-visible spectrophotometry. Results: Hemoglobin-based oxygen carrier solutions had substantial absorbance at 415 nm, the wavelength of analysis used to measure the formation of 4-nitrophenol. In addition to offsetting the initial absorbance at the analytical wavelength, polymerized hemoglobin gave rise to a strong negative interference plot because of alkali denaturation of the substitute. The same interference mechanism was also observed for native hemoglobin (hemolysate), indicating that the interference was not derived from the polymerization process. The interference can be corrected by implementing a rate-correction procedure, or the interference can be avoided by measurement at 450 nm. Conclusions: The interference of polymerized hemoglobin in the alkaline phosphatase assay is a result of an absorbance offset caused by alkali denaturation of hemoglobin. The interference can be corrected or avoided by modifying the calculation or the analytical wavelength. The correction strategy may also be applicable to improving the hemolysis index for this method.

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A Hemoglobin Based Oxygen Carrier, Bovine Polymerized Hemoglobin (HBOC-201) versus Hetastarch (HEX) in an Uncontrolled Liver Injury Hemorrhagic Shock Swine Model with Delayed Evacuation

Journal of Trauma and Acute Care Surgery ◽

10.1097/01.ta.0000147520.84792.b4 ◽

2004 ◽

Vol 57 (4) ◽

pp. 726-738 ◽

Cited By ~ 40

Author(s):

Jennifer Gurney ◽

Nora Philbin ◽

Jennifer Rice ◽

Françoise Arnaud ◽

Feng Dong ◽

...

Keyword(s):

Liver Injury ◽

Hemorrhagic Shock ◽

Oxygen Carrier ◽

Swine Model ◽

Polymerized Hemoglobin

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A polymerized hemoglobin based oxygen carrier attenuates TLR4 stimulated NF-kB activation by inhibiting phosphorylation of IkB-a

Journal of the American College of Surgeons ◽

10.1016/j.jamcollsurg.2005.06.066 ◽

2005 ◽

Vol 201 (3) ◽

pp. S34-S35

Author(s):

Aaron M. Cheng ◽

Ernest E. Moore ◽

Jeffrey Johnson ◽

Mark Walsh ◽

Christine Hamiel ◽

...

Keyword(s):

Oxygen Carrier ◽

Polymerized Hemoglobin

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Direct Observation of Chain Lengths and Conformations in Oligofluorene Distributions from Controlled Polymerization by Double Electron-Electron Resonance

10.26434/chemrxiv.10002785 ◽

2019 ◽

Author(s):

Dennis Bücker ◽

Annika Sickinger ◽

Julian D. Ruiz Perez ◽

Manuel Oestringer ◽

Stefan Mecking ◽

...

Keyword(s):

Chain Length ◽

Length Distribution ◽

Catalyst System ◽

Chain Conformation ◽

Controlled Polymerization ◽

Chain Length Distribution ◽

Electron Resonance ◽

Double Electron ◽

The Individual ◽

Double Electron Electron Resonance

Synthetic polymers are mixtures of different length chains, and their chain length and chain conformation is often experimentally characterized by ensemble averages. We demonstrate that Double-Electron-Electron-Resonance (DEER) spectroscopy can reveal the chain length distribution, and chain conformation and flexibility of the individual n-mers in oligo-(9,9-dioctylfluorene) from controlled Suzuki-Miyaura Coupling Polymerization (cSMCP). The required spin-labeled chain ends were introduced efficiently via a TEMPO-substituted initiator and chain terminating agent, respectively, with an in situ catalyst system. Individual precise chain length oligomers as reference materials were obtained by a stepwise approach. Chain length distribution, chain conformation and flexibility can also be accessed within poly(fluorene) nanoparticles.

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