Preparation, characterization and in vitro release of β-galactosidase loaded polyelectrolyte nanoparticles

Improving encapsulation efficacy (EE) and bioavailability of β-galactosidase (β-gal) is always a challenge due to its fragility. In this work, β-gal loaded β-chitosan (CS) nanoparticles (NPs) were successfully prepared based on ionic gelation technique and electrostatic attraction for improving its EE and in vitro releasing capacity. The particle size of β-gal loaded low and high molecular weight (LMW and HMW) β-CS NPs reached 584.37 and 652.46 nm, with Zeta-potential (ZP) of 26.37 and 16.46 mV under the optimal conditions, respectively. In vitro release study conducted at pH 4.5 and 7.4 showed that β-gal loaded LMW and HMW β-CS NPs with EE of 68.32 and 58.64% sustained the release of the β-gal over 12 h. The β-gal incorporated into β-CS NPs was confirmed with the results of physicochemical and structural properties of β-gal loaded β-CS NPs, and prepared NPs had hardly any cytotoxicity in the range of 0.1-1.0 mg/mL. The results indicated that β-gal loaded β-CS NPs could serve as non-toxic delivery carriers for the treatment of lactose intolerance.