Improved oxygen storage capacity of haemoglobin submicron particles by one-pot formulation

The coprecipitation-cross-linking-dissolution (CCD) technique for protein submicron particle fabrication was improved by omitting one preparation step using the macromolecular cross-linker, periodate-oxidized dextran (Odex, M.W. of 40 and 70 kDa). The coprecipitation and cross-linking of haemoglobin (Hb) were combined in one single step since the cross-linker is incorporated into the inorganic template, MnCO₃, together with the protein. After removal of the MnCO₃ templates by EDTA, the amount of entrapped Hb was 60 to 70% of the initial amount. This technique provides deformable Hb submicron particles (HbMP) with narrow size distribution between 800 and 1000 nm, uniform morphology and negative zeta-potential. More than 40% of Hb in the particles was able to carry oxygen over a storage period of 90 days. The results suggest that our new protein submicron particle fabrication technique minimizes the fabrication time and is very efficient and cost-effective.