Physical, Chemical, and Biological Properties of Chitosan-Coated Alginate Microparticles Loaded with Porcine Interleukin-1β: A Potential Protein Adjuvant Delivery System

Abstract

We previously developed chicken interleukin-1β (IL-1β) mutants as single-dose adjuvants that induce protective immunity when co-administered with an avian vaccine. However, livestock such as pigs may require a vaccine adjuvant delivery system that provides long-lasting protection to reduce the need for successive booster doses. Therefore, we developed chitosan-coated alginate microparticles as a carrier for bovine serum albumin (BSA) or porcine IL-1β (pIL-1β) and assessed their physical, chemical, and biological properties. Electrospraying of the BSA-loaded alginate microparticles (BSA/ALG MPs) resulted in an encapsulation efficiency of 50%, and those MPs were then coated with chitosan (BSA/ALG/CHI MPs). Optical and scanning electron microscopy, zeta potential analysis, and Fourier transform infrared spectroscopy were used to characterize these MPs. The BSA encapsulation parameters were applied to ALG/CHI MPs loaded with pIL-1β, which were not cytotoxic to porcine fibroblasts but had enhanced bio-activity over unencapsulated pIL-1β. The chitosan layer of the BSA/ALG/CHI MPs prevented burst release and facilitated sustained release of pIL-1β for at least 28 days. In conclusion, BSA/ALG/CHI MPs prepared as a carrier for pIL-1β may be used as an adjuvant for the formulation of pig vaccines.

Chitosan-Coated Alginate Microcapsules of a Full-Spectrum Cannabis Extract: Characterization, Long-Term Stability and In Vitro Bioaccessibility

“…Zeta-potential measurements revealed that the surface charge of capsules was 15 ± 6 mV. This positive value of zeta potential confirmed that a positively charged chitosan layer was formed successfully above the calcium alginate polymeric structure [ 41 , 42 , 43 , 44 ]. Zeta-potential values above 30 mV are usually sought in order to avoid particle aggregation or flocculation in aqueous dispersion [ 41 , 45 , 46 ] and as reported by Khan et al in their study with resveratrol alginate–chitosan zein nanocapsules; this zeta potential could be increased with higher chitosan to alginate ratios [ 43 ].…”

“…Many of the factors that affect particle size (i.e., alginate concentration, voltage, needle size, encapsulation flowrate and hardening solution’s surface tension, viscosity and stirring rate [ 26 , 49 , 50 ]) were previously optimized following the same methodology used in our research group [ 24 ]. Hence, the lack of complete sphericity could be attributed to the freeze-drying step, which affects negatively the sphericity [ 42 , 51 ].…”

Encapsulation of Bioactive Peptides by Spray-Drying and Electrospraying

“…Carriers commonly used were alginate, PEO and NOSC, all of which are particularly used for the formulation of oral delivery drugs since they are all safe and present high biocompatibility. Alginate was used to encapsulate α-calcitonin gene-related peptide (α-CGRP) [97] and BSA/porcine interleukin-1β (pIL-1β) [100], both by blend electrospraying and resulting in particles with widely differing sizes, ranging from 194.23 ± 10.08 to 20 µm, respectively. PEO is a synthetic semicrystalline polymer mostly used for electrospinning due to its rheological characteristics, and thus only one work used it for electrospraying the enzyme alkaline phosphatase [95,104].…”

Microparticles in the Development and Improvement of Pharmaceutical Formulations: An Analysis of In Vitro and In Vivo Studies

“…Attributes such as controlled, sustained and specific release to cells and/or tissues can be conferred to microparticles. It is also possible to administer poorly soluble drugs [ 12 ], to overcome epithelial and endothelial barriers [ 13 ], co-administer two or more bioactive agents for combined therapy [ 14 ], select adjuvants for improving the immune response of vaccines [ 15 ], and increase effectiveness, safety and bioavailability of therapeutic agents [ 16 ].…”