Immunoadjuvant potential of cross-linked dextran microspheres mixed with chitosan nanospheres encapsulated with tetanus toxoid

Abstract

Context: Nasal mucosa is a desirable route for mucosal vaccine delivery. Mucosal co-administration of chitosan nanoparticles with absorption enhancers such as cross-linked dextran microspheres (CDM, Sephadex®) is a promising antigen delivery system.Objective: In the current study, the chitosan nanospheres loaded with tetanus toxoid (CHT:TT NPs) was prepared and characterized. The immune responses against tetanus toxoid after nasal administration of CHT:TT NPs alone or mixed with CDM were also determined.Materials and methods: Chitosan nanospheres were prepared by ionic gelation method. Particle size, releasing profile and antigen stability were evaluated by dynamic light scattering, diffusion chamber and SDS-PAGE methods, respectively. Rabbits were nasally immunized with different formulations loaded with 40 Lf TT. After three times immunizations with 2 weeks intervals, sera IgG titres and nasal lavage sIgA titres were determined.Results: Mean size of CHT NPs and CHT:TT NPs were 205 ± 42 nm and 432 ± 85 nm, respectively. The release profile showed that 42.4 ± 10.5% of TT was released after 30 min and reached to a steady state after 1.5 h. Stability of encapsulated TT in nanospheres was confirmed by SDS-PAGE. The antibody titres showed that CHT:TT NPs-induced antibody titres were higher than TT solution. CHT NPs mixed with CDM induced the systemic IgG and nasal lavage sIgA titres higher than intranasal administration of TT solution (p < 0.001).Discussion and conclusion: As the results indicated, these CHT:TT NPs when co-administered with CDM were able to induce more immune responses and have the potential to be used in mucosal immunization.

Biological properties the novel application of N-trimethyl chitosan nanospheres as a stabilizer and preservative in tetanus vaccine

“…So, observing any stabilizing or preservative activity can be specifically referred to chitosan. Pirouzmand et al and Walke et al did not mention the purity of their TT protein or the existence of other components in their study [ 17 18 ].…”

“…The final solution was centrifuged at 14,000 g for about 30 minutes to separate the produced N-TMCNS. In order to estimate the amount of TT loaded in the N-TMCNS, the concentration of remaining TT in the supernatant was determined spectrophotometrically using Bradford protein assay and the encapsulation efficiency (EE%) was calculated as follows [ 17 ]:…”

<p>Novel Drug Delivery Systems for Loading of Natural Plant Extracts and Their Biomedical Applications</p>

“…Immunomagnetic NS can be prepared by combining the above two kinds of NS, which could significantly improve its targeting. 144 Most nanospheres are prepared with biodegradable, biocompatible, and synthetic polymers such as polylactic acid (PLA), polyglycolic acid (PGA), and their co-polymer polylactide-coglycolide (PLGA) using emulsion evaporation technique. 144 Moreover, NS can be also prepared using pre-formed polymers by nanoprecipitation (omitting the oil in the formulation) or interfacial deposition of polymer (containing the oil).…”

Chitin/Chitosan: Versatile Ecological, Industrial, and Biomedical Applications

“…Chitosan-derived adjuvants were also used in combination with antigens derived from bacterial toxins, such as diphtheria toxoids (McNeela et al 2000;Schipper et al 2017), tetanus toxoids (Ahire et al 2007;Pirouzmand et al 2017), and dermonecrotoxin (Jiang et al 2004). In addition, the potential of various vaccine formulations against anthrax were evaluated in female BALB/c mice (Malik et al 2018).…”