Preparation and sustainable release of modified konjac glucomannan/chitosan nanospheres

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.