Hyaluronic acid interaction with chitosan-conjugated magnetite particles and its purification

The polyelectrolyte complex (PEC) effect between hyaluronic acid (HA) and chitosan was explored to recover HA from fermentation broth. Chitosan was conjugated with the magnetic nanoparticles by co-precipitation method to facilitate its recovery. The magnetic chitosan particles (chitosan–magnetite) have an average size about 5 μm and point of zero charge (PZC) around 6.5. pH lower than PZC favored the HA capture. About 39 mg of HA was captured per gram of particles at pH 6. Nearly quantitative release of captured HA was achieved at pH 8. Although HA could not be directly isolated from Streptococcus zoopedemics fermentation broth by manipulating pH between 6 and 8, HA free of contaminant protein could be purified from the crude ethanol precipitate using chitosan–magnetite.