Antigen-Inorganic Hybrid Flowers-Based Vaccines with Enhanced Room Temperature Stability and Effective Anticancer Immunity.

Particle-based antigen carriers as adjuvants play an important role in vaccine development. Herein, an antigen-inorganic hybrid flower-like particle is developed as a novel vaccine carrier. Model antigen ovalbumin (OVA)-copper (II) sulfate hybrid vaccines (OVA-Cu-HVs) are mildly and facilely constructed through a biomimetic mineralization process. OVA-Cu-HVs facilitate cellular uptake in antigen-presenting cells and the internalization of OVA-Cu-HVs involves macropinocytosis-mediated endocytosis. OVA-Cu-HVs can release OVA in a pH-responsive behavior and promote cytosolic release of antigen to enhance antigen cross-presentation. Immunization with OVA-Cu-HVs promotes the maturation of dendritic cells in draining lymph nodes, induces robust antigen-specific T lymphocyte response, and inhibits tumor growth in vivo. In addition, OVA-Cu-HVs are efficacious after being stored for 4 weeks at room temperature and are expected to simplify vaccine storage and lower the cost of cold storage for transportation. Looking forward, OVA-Cu-HVs may hold strong potential to be as an effective vaccine delivery platform, which will facilitate the application of organic-inorganic hybrid flowers in biomedical areas.

Controlled Fabrication of Silk Protein Sericin Mediated Hierarchical Hybrid Flowers and Their Excellent Adsorption Capability of Heavy Metal Ions of Pb(II), Cd(II) and Hg(II).

Fabrication of protein-inorganic hybrid materials of innumerable hierarchical patterns plays a major role in the development of multifunctional advanced materials with their improved features in synergistic way. However, effective fabrication and applications of the hybrid structures is limited due to the difficulty in control and production cost. Here, we report the controlled fabrication of complex hybrid flowers with hierarchical porosity through a green and facile coprecipitation method by using industrial waste natural silk protein sericin. The large surface areas and porosity of the microsize hybrid flowers enable water purification through adsorption of different heavy metal ions. The high adsorption capacity depends on their morphology, which is changed largely by sericin concentration in their fabrication. Superior adsorption and greater selectivity of the Pb(II) ions have been confirmed by the characteristic growth of needle-shaped nanowires on the hierarchical surface of the hybrid flowers. These hybrid flowers show excellent thermal stability even after complete evaporation of the protein molecules, significantly increasing the porosity of the flower petals. A simple, cost-effective and environmental friendly fabrication method of the porous flowers will lead to a new solution to water pollution required in the modern industrial society.