Increasing the stability of Lumbricus terrestris erythrocruorin via poly(acrylic acid) conjugation.

ABSTRACT: Since donated red blood cells must be constantly refrigerated, they are often unavailable in remote areas and battlefields. The goal of this study was to synthesize a highly stable blood substitute that does not require refrigeration. Specifically, the extracellular haemoglobin (a.k.a. erythrocruorin, Ec) of the earthworm Lumbricus terrestris erythrocruororin (LtEc) was cross-linked with poly(acrylic acid) (PAA) and ethylene diamine (EDA). PAGE analysis of the LtEc nanoparticles reveals cross-linking between subunits, while dynamic light scattering and scanning electron microscopy show that cross-linking significantly increases the size of the LtEc nanoparticles (164?±?13.9?nm). Cross-linking also significantly increased the thermal stability of the LtEc nanoparticles by 10?°C (Tm?=?72?±?0.84?°C) relative to native LtEc (Tm?=?62?±?0.6?°C). In addition, while native LtEc rapidly dissociates at pH 9, the LtEc nanoparticles resist subunit dissociation up to pH 10. The oxygen affinity of the LtEc nanoparticles (P50?=?6.85?±?0.13?mm Hg) is much higher than native LtEc (P50?=?26.67?±?0.4?mm Hg), but the cooperativity (n?=?2.43?±?0.12) is not affected. Altogether, these results show that cross-linking LtEc with PAA and EDA provides a potential blood substitute with increased stability and oxygen affinity.

SUBMITTER: Spivack K 

PROVIDER: S-EPMC6476418 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature