Chitosan/sulfated locust bean gum nanoparticles: In vitro and in vivo evaluation towards an application in oral immunization

Abstract

This work proposes the design of nanoparticles based on locus bean gum (LBG) and chitosan to be used as oral immunoadjuvant for vaccination purposes. LBG-based nanoparticles were prepared by mild polyelectrolyte complexation between chitosan (CS) and a synthesized LBG sulfate derivative (LBGS). Morphological characterization suggested that nanoparticles present a solid and compact structure with spherical-like shape. Sizes around 180-200nm and a positive surface charge between +9mV and +14mV were obtained. CS/LBGS nanoparticles did not affect cell viability of Caco-2 cells after 3h and 24h of exposure when tested at concentrations up to 1.0mg/mL. Two model antigens (a particulate acellular extract HE of Salmonella enterica serovar Enteritidis, and ovalbumin as soluble antigen) were associated to CS/LBGS nanoparticles with efficiencies around 26% for ovalbumin and 32% for HE, which resulted in loading capacities up to 12%. The process did not affect the antigenicity of the associated antigens. BALB/c mice were orally immunized with ovalbumin-loaded nanoparticles (100μg), and results indicate an adjuvant effect of the CS/LBGS nanoparticles, eliciting a balanced Th1/Th2 immune response. Thus, CS/LBGS nanoparticles are promising as antigen mucosal delivery strategy, with particular interest for oral administration.

Dual antibiotherapy of tuberculosis mediated by inhalable locust bean gum microparticles

“…Drug-loaded LBG microparticles had stronger impact in released LDH ( Figure 5) compared with the effect on mitochondrial dehydrogenase activity assessed in MTT assay ( Figure 4B). Other studies report similar observations (Braz et al, 2017;Wang et al, 2009) and several justifications may apply. In fact, the two assays evaluate different aspects of the interaction between cells and particles.…”

β-lactoglobulin micro- and nanostructures as bioactive compounds vehicle: In vitro studies

“…Cytotoxicity test on Caco-2 cells were performed by MTT conversion assay (Braz et al, 2017;Ren et al, 2018), according to Tibolla et al (2019) procedure. Briefly, β-Lg micro-(24 × 10 −3 to 13.5 mg mL −1 ), nanostructures (1 -4.5 mg mL −1 ), β-Lg micro-and nanostructures associated to riboflavin (21 × 10 −3 to 94.5 × 10 −3 mg mL −1 riboflavin), β-Lg micro-and nanostructures associated to quercetin (0.128 × 10 −3 to 40 × 10 −3 mg mL −1 quercetin), free bioactive model compounds and ethanol (in equivalent quercetin concentrations) were diluted in supplemented DMEM medium and homogenized.…”

Recent Advances in Artificially Sulfated Polysaccharides for Applications in Cell Growth and Differentiation, Drug Delivery, and Tissue Engineering

“…In 2017, Sarmento et al. synthesized sulfated LBG with SO 3 ⋅ DMF complex and reported, for the first time, the production of nanoparticles through complexation with chitosan by means of an electrostatic interaction . The studies further indicated that chitosan/LBG sulfate nanoparticles were promising for the development of an antigen delivery strategy.…”

“…In addition to CS and CHS, there are also sulfates of af ew other polysaccharides, such as starch sulfate, dextran sulfate, pullulan sulfate, sulfated LBG, and heparosan sulfate, that can act as GAG analogues in biomedical fields. [96][97][98][99][100][101][102][103][104][105][106][107][108] These diverse GAG analogues can be synthesized through versatile synthetic methods (Scheme 3). [96][97][98][99][100][101][102][103][104][105][106][107][108] The chemical structuresc an be determined through various methods,i ncluding FTIR, FT Raman, NMR spectroscopy,and elemental analysis.…”