Preparation and sustainable release of modified konjac glucomannan/chitosan nanospheres

• A novel CKGM/HACC composite nanospheres were prepared.
• The particle size and zeta potential of the nanospheres are tunable.
• CKGM/HACC/OVA has good sustained release properties for OVA in vitro.
• The raw materials are low toxicity, good biocompatibility and biodegradability.
• The polyelectrolyte complexes method is organic solvent free, and convenient.

Biodegradable and biocompatible polymer nanospheres are useful materials for controlled drug delivery. In the present study, novel composite nanospheres were prepared from carboxymethyl konjac glucomannan (CKGM) and 2-hydroxypropyl trimethyl ammonium chloride chitosan (HACC) as a vaccine delivery vehicle by electrostatic complexation in a neutral aqueous solution without the use of chemical crosslinkers. By altering the CKGM and HACC concentrations, the average CKGM/HACC particle size could be tuned from approximately 600 nm to 1460 nm and the zeta potential from 39 mV to 50 mV. Furthermore, using ovalbumin (OVA) as a model molecule for vaccines, various parameters were determined to affect the CKGM/HACC nanosphere encapsulation efficiency and in vitro controlled release properties. Under optimum conditions, the OVA encapsulation efficiency of CKGM/HACC nanospheres was 71.8%, while sustained and continuous in vitro OVA release over a period of more than 24 h was observed. Therefore, CKGM/HACC nanospheres are novel drug delivery carriers with great potential for medical applications.