N-2-Hydroxypropyl Trimethyl Ammonium Chloride Chitosan as Adjuvant Enhances the Immunogenicity of a VP2 Subunit Vaccine against Porcine Parvovirus Infection in Sows

Porcine parvovirus (PPV) is the most important infectious agent causing infertility in pigs, which can be prevented by routine vaccination. Successful vaccination depends on the association with potent adjuvants that can enhance the immunogenicity of antigen and activate the immune system. Polysaccharide adjuvant has low toxicity and high safety, and they can enhance the humoral, cellular and mucosal immune responses. In the present study, we prepared the VP2 protein subunit vaccine against PPV (PPV/VP2/N-2-HACC) using water-soluble N-2-Hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC) as the vaccine adjuvant, and the ability of the PPV/VP2/N-2-HACC to induce immune responses and protect sows from PPV infection was evaluated. In vivo immunization showed that the sows immunized with the PPV/VP2/N-2-HACC by intramuscular injection produced higher HI antibody levels and long-term immune protection compared with the other groups, while the subunit vaccine did not stimulate the proliferation of CD4+ and CD8+ T lymphocytes to trigger the secretion of higher levels of IL-2, IL-4, IFN-α, IFN-β, and IFN-γ, indicating that the PPV/VP2/N-2-HACC mainly induced humoral immunity rather than cellular immunity. PPV was not detected in the viscera of the sows immunized with the PPV/VP2/N-2-HACC, and the protective efficacy was 100%. Collectively, our findings suggested that the N-2-HACC was a potential candidate adjuvant, and the PPV/VP2/N-2-HACC had immense application value for the control of PPV.

Intranasal immunization with O-2′-Hydroxypropyl trimethyl ammonium chloride chitosan nanoparticles loaded with Newcastle disease virus DNA vaccine enhances mucosal immune response in chickens

Background There has been a great interest in developing strategies for enhancing antigen delivery to the mucosal immune system as well as identifying mucosal active immunostimulating agents. To elevate the potential of O-2ʹ-Hydroxypropyl trimethyl ammonium chloride chitosan (O-2ʹ-HACC) as an adjuvant and mucosal immune delivery carrier for DNA vaccine, we prepared the O-2ʹ-HACC loaded with Newcastle disease virus (NDV) F gene plasmid DNA and C3d6 molecular adjuvant (O-2ʹ-HACC/pFDNA microparticles). Results The O-2ʹ-HACC/pFDNA exhibited a regular spherical morphology with a particle size of 202.3 ± 0.52 nm, a zeta potential of 50.8 ± 8.21 mV, encapsulation efficiency of 90.74 ± 1.10%, and a loading capacity of 49.84 ± 1.20%. The plasmid DNA could be sustainably released from the O-2ʹ-HACC/pFDNA after an initial burst release. Intranasal vaccination of chickens immunized with O-2ʹ-HACC/pFDNA not only induced higher anti-NDV IgG and sIgA antibody titers but also significantly promoted lymphocyte proliferation and produced higher levels of IL-2, IL-4, IFN-γ, CD4+, and CD8 + T lymphocytes compared with the NDV commercial live attenuated vaccine. Intranasal delivery of the O-2ʹ-HACC/pFDNA enhanced humoral, cellular, and mucosal immune responses and protected chickens from the infection of highly virulent NDV compared with the intramuscular delivery. Conclusions Collectively, our findings indicated that the O-2ʹ-HACC could be used as a vaccine adjuvant and delivery system for mucosal immunity and have an immense application promise. Graphic Abstract

Enhancing the mechanical properties of bismaleimide resin with montmorillonite modified by two intercalators (amino-terminated polyoxypropylene and octadecyl trimethyl ammonium chloride)

Purpose Bismaleimide (BMI) is a kind of thermosetting resin and its application is usually limited by low toughness. In this paper, two kinds of reinforcement intercalator amino-terminated polyoxypropylene (POP) and octadecyl trimethyl ammonium chloride (OTAC) were designed and synthesized to toughen BMI resin and the toughening effect was compared and analyzed. The purpose of this paper is to toughen BMI resin and analyze the toughening effect of two reinforcements intercalator amino-terminated polyoxypropylene (POP) and octadecyl trimethyl ammonium chloride (OTAC). Design/methodology/approach Sodium-based montmorillonite (Na-MMT) was modified by POP and OTAC, and the ion-exchange reaction obtained organic montmorillonite (POP-MMT and OTAC-MMT). The polymer matrix (MBAE) was synthesized, in which 4,4’-diamino diphenyl methane BMI was used as the monomer and 3,3’-diallyl bisphenol A and bisphenol A diallyl ether were used as active diluents. And then, POP-MMT/MBAE and OTAC-MMT/MBAE composites were prepared using MBAE as matrix and POP-MMT or OTAC-MMT as reinforcement. The Fourier-transform infrared, X-ray diffraction and scanning electron microscope (SEM) of the filler and microstructure and mechanical properties of the composite were characterized to the better reinforcement. Findings POP-MMT and OTAC-MMT enhanced BMI-cured products’ toughness by generating microcracks in the polymer to absorb more fracture energy. Meanwhile, POP-MMT and OTAC-MMT were the main stress components and the enhancement of the interface interaction was beneficial to transfer the external force from the matrix to the reinforcement and improved the mechanical properties of the composite. Furthermore, with the intercalation rate increasing, the compatibility of the two phases was increased and the performance of MBAE was also elevated. Research limitations/implications BMI is generally used as aerospace structural materials, functional materials, impregnating paint and other fields. However, high crosslinking density leads to moulding material’s brittleness and limits a wider range of applications. Therefore, it has become an urgent priority to explore and improve the mechanical properties of BMI resin. Originality/value POP and OTAC have successfully intercalated Na-MMT layers to get POP-MMT and OTAC-MMT, and the interplanar crystal spacing and the intercalation rate were calculated, respectively. The results were corresponding with the SEM images of POP-MMT and OTAC-MMT. After that, the morphology of composites illustrated the compatibility was related to the intercalation rate. According to the mechanism of modified MMT toughening epoxy resin, when they were dispersed uniformly in the matrix, the composite’s mechanical properties had been significantly improved. Additionally, OTAC-MMT with a higher intercalation rate had better compatibility and interfacial force with the matrix, so that the mechanical properties of OTAC-MMT/MBAE were the best.

Intranasal Immunization With O-2′-Hydroxypropyl Trimethyl Ammonium Chloride Chitosan Nanoparticles Loaded With Newcastle Disease Virus DNA Vaccine Enhance Mucosal Immune Response in Chickens

Background: There is a great interest to develop strategies for enhancing antigen delivery to mucosal immune system as well as to identify mucosal active immunostimulating agents. To elevate the potential of O -2′-Hydroxypropyl trimethyl ammonium chloride chitosan (O-2′-HACC) nanoparticles as adjuvant and mucosal immune delivery carrier for DNA vaccine, we prepared the O-2′-HACC nanoparticles loaded with Newcastle disease virus F gene plasmid DNA with C3d6 molecular adjuvant (O-2′-HACC/pFDNA). Results: The O-2′-HACC/pFDNA had regular spherical morphology with a particle size of 202.3±0.52 nm, zeta potential of 50.8±8.21 mV, encapsulation efficiency of 90.74±1.10 %, and loading capacity of 49.84±1.20 %. The plasmid DNA could be sustainably released from the O-2′-HACC/pFDNA after an initial burst release. Intranasal vaccination of chickens immunized with O-2′-HACC/pFDNA not only induced higher anti-NDV IgG and sIgA antibody titers, but also significantly promoted lymphocyte proliferation and produced the higher levels of IL-2, IL-4, IFN-γ, CD4+ and CD8+ T lymphocytes than the NDV commercial attenuated live vaccine. Intranasal delivery of the O-2′-HACC/pFDNA enhanced humoral, cellular and mucosal immune responses, and protected chickens from the infection of highly virulent NDV than intramuscular delivery. Conclusions: This study indicated that the O-2′-HACC nanoparticles could be used as vaccine adjuvant and delivery system for mucosal immunity and have an immense application promise.

Synthesis, Surface Tension, Flocculation and Antibacterial Properties of Cationic Copolymer Methacryloxyethyl Trimethyl Ammonium Chloride-Butyl Acrylate-Acrylamide

Three cationic copolymers methacryloxyethyl trimethyl ammonium chloride-butyl acrylate-acrylamide (MTAC-BA-AM terpolymer) were designed and synthesized by emulsion polymerization. Their structures were confirmed by FT-IR and 1H NMR. The effect of content of hydrophobic monomer butyl acrylate (BA) in MTAC-BA-AM terpolymer on surface activities, flocculation and antibacterial properties were investigated. The study of surface tension shows that MTAC-BA-AM terpolymer has good surface activity due to the introduction of hydrophobic monomer BA. The flocculation experiment showed that the light transmittance of the kaolin suspension supernatant was 98.13% when the dose of MTAC-BA-AM terpolymer in the kaolin suspension was 0.03 mg/L, which was obviously better than the P(MTAC-AM) (91.02%) without hydrophobic modification of BA. The bacteriostatic experiment of MTAC-BA-AM terpolymer showed that as the content of hydrophobic monomer BA in MTAC-BA-AM terpolymer increased the inhibitory rate of MTAC-BA-AM terpolymer aginst Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus)

Understanding the Reaction Crystallization Process of Glycidyl Trimethyl Ammonium Chloride

Reaction crystallization to produce glycidyl trimethyl ammonium chloride (GTA) via epichlorohydrin with gas-state trimethylamine was investigated. The crystallization process of the GTA gas-liquid reaction was optimized by a seed method. The optimized technology can prepare GTA products with crystal form and purity greater than 97%. The crystallization process of GTA consists of four steps (i.e., addition of seed, dispersion of seed, growth of crystals on the seed surfaces, agglomeration and growth of crystal). Seed method and flow rate are the key factors affecting purity. The purity and particle size of GTA crystals were satisfactory as long as the operation was kept within the defined envelope. The experiments were conducted on a 1 L reactor and successfully scaled-up to 3000 L in industry.