A xanthan gum and carbomer-codispersed divalent manganese ion-loaded tannic acid nanoparticle adjuvanted inactivated pseudorabies virus vaccine induces balanced humoral and cellular immune responses.

Adjuvants including aluminum adjuvant (Alum) and oil-water emulsion have been widely used in inactivated pseudorabies virus (PRV) vaccines to improve their performance, however, they are not sufficient to protect from PRV infection because of the weak immune response and poor Th1-type immune response. Divalent manganese ion (Mn2+) has been reported to increase the cellular immune response significantly. In this work, a xanthan gum and carbomer-dispersed Mn2+-loaded tannic acid-polyethylene glycol (TPMnXC) nanoparticle colloid is developed and used as an adjuvant to improve the performance of the inactivated PRV vaccine. The good in vitro and in vivo biocompatibility of the developed TPMnXC colloid has been confirmed by the cell viability assay, erythrocyte hemolysis, blood routine analysis, and histological analysis of mouse organs and injection site. The TPMnXC-adjuvanted inactivated PRV vaccine (TPMnXC@PRV) significantly promotes higher and more balanced immune responses indicating with an increased specific total IgG antibody and IgG2a/IgG1 ratio, efficient splenocytes proliferation, and elevated Th1- and Th2-type cytokine secretion than those of control groups. Wild PRV challenge experiment is performed using mice as a model animal, achieving a protection rate of up to 86.67 %, which is much higher than those observed from the commercial Alum. This work not only demonstrates the high potentiality of TPMnXC in practical applications but also provides a new way to develop the Mn2+-loaded nanoadjuvant for veterinary vaccines.

In vitro biocompatiability and mechanical properties of bone adhesive tape composite based on poly(butyl fumarate)/poly(propylene fumarate)-diacrylate networks.

Polyfumarate has been considered as injectable and biodegradable bone cement. However, its mechanical and degradation properties are particularly important. Therefore, the current study aimed to develop the properties by compositing poly (butyl fumarate)-based networks with hydroxyapatite nano-powders. In this regard, the poly (butyl fumarate) (PBF) matrix composite was compared with different components by evaluating their composition, mechanical properties, hydrophilicity, and biodegradability. Furthermore, their bioactivity in the phosphate-buffered saline (PBS) and, via applying mouse embryo osteoblast precursor cells (MC3T3-E1), their cell interaction, including adhesion, proliferation, and in vitro cytotoxicity assay, were assessed. The addition of hydroxyapatite improved the mechanical strength and modulus of PBF matrix composite. The composite reinforced with 3 wt% hydroxyapatite showed a higher lap-shear strength (1.68 MPa) and bonding strength (4.30 MPa), a maximum compression strength at fracture (95.18 MPa), modulus (925.29 MPa), and compression strength at yield (31.43 MPa), respectively. Also, hydrophilicity and in vitro degradation of the composite were enhanced in the presence of hydroxyapatite. In this condition, after a period of immersion (52 weeks) in PBS, the weight loss rate, and degradation rate of the composite increased. The composite proliferation, adhesion, and toxicity of MC3T3-E1 cells improved in comparison to the PBF matrix composite. Accordingly, controllable strength and degradation of the composite, along with its proven biocompatibility, make the composite a candidate for the treatment of comminuted fractures.