Preparation and Evaluation of rhINF-α-2b Sodium Hyaluronate Cross-Linked Porous Microspheres: Characterization, Sustained-Release Properties, and Antitumor Activity.

Abstract

Recombinant human interferon α-2b (rhINF-α-2b), like most proteins, has several shortcomings such as relatively short half-life, low therapeutic index, high circulating drug fluctuations, and rapid degradation which could hinder its effective delivery. Novel electrostatic spray and ion exchange drug-loading techniques were combined to formulate rhINF-α-2b sodium hyaluronate cross-linked porous sustained-release microspheres (rhINF-α-2b-SHCPM), a protein delivery system. The different properties of rhINF-α-2b-SHCPM including the physicochemical nature, in vitro release behavior, and antitumor activity were evaluated. The loading rate (10.31 ± 0.94%) and encapsulation efficiency (89.09 ± 2.37%) of rhINF-α-2b-SHCPM produced acceptable values. The in vitro cumulative release rate of rhINF-α-2b-SHCPM within 24 h was also 86.26 ± 2.11% with a much better sustained release effect. Thus, the half-life (10.763 h) and retention time (14.067 h) of rhIFNα-2b-SHCPM were significantly prolonged with enhanced bioavailability (43,198.387 ng/L*h) and decreased peak concentration (15,266.4 ngL-1) compared with the free rhIFNα-2b protein (0.912 h, 0.952 h, 34,749.048 ng/L*h, and 48,870.2 ngL-1, respectively). The in vitro anti-proliferative activity and in vivo tumor inhibitory rate of rhIFNα-2b-SHCPM also increased by 90 and 55.86%, respectively, compared with the free rhIFNα-2b solution. The findings significantly supported a well-developed protein delivery system with improved sustained release, acceptable bioavailability, and increased antitumor activities. Graphical Abstract.