Search

The objective of this study is to develop a new hepatitis B surface antigen (HBsAg) delivery system by coating soluble microneedle arrays with mannose-modified PLGA nanoparticles (MNPs). MNPs of different sizes were synthesized. The effects these nanoparticles on the maturation of dendritic cells were studied by flow cytometry. HBsAg-containing MNPs (HBsAg/MNPs) of the appropriate sizes were coated into water-soluble microneedle arrays. The in vitro characteristics of microneedles arrays and the immune responses after subcutaneous administration in mice were studied. The results showed that PLGA nanoparticles with an average size of about 800 nm showed the most significant effects in stimulating the maturation of dendritic cells. In the water-soluble microneedle array, the targeted PLGA nanoparticles containing HBsAg were distributed discretely with a maximum distribution height of about 280 μm with a drug load of 0.98 ± 0.05 μg/mg. The drug-containing microneedle arrays exhibited excellent mechanical properties and improved biosafety. The results of immune responses in vivo showed that the subcutaneous administration of the microneedle arrays induced the proliferation of splenocyte, secreted specific IL-12 and IFN-γ, and promote the production of IgG in mice. This study verifies the feasibility of soluble composited microneedles administration in hepatitis B immunization, and provides new ideas for the development and application of non-injectable vaccine delivery systems., (© 2023. The Author(s), under exclusive licence to American Association of Pharmaceutical Scientists.)

Antigen-adjuvant combination could induce a protective and long-lasting anti-tumor immune response. However, exploiting system which could co-deliver melanoma antigen peptide Trp2 (Tyrosinase-related protein 2) and Toll-like-receptor-7 (TLR7) agonists imiquimod (R837) both are poor aqueous solubility is still challenging. Our new nanocomplex was explored for specific delivery of Trp2 and R837 into antigen-presenting cells (APCs). R837 was loaded into mannosylated-β-cyclodextrin (Man-CD) to target dendritic cells (DCs) by binding mannose receptors (MR) on DCs. A fusion peptide (WT) was constructed by incorporating the amino acid region of TAT (cell-penetrating peptide) into Trp2 to improve the TAT-mediated intracellular efficiency. Negatively charged sodium alginate (SA), a biocompatible polymer, which can induce adjuvant responses by affecting the functions of DCs, was complexed with Man-CD/R837 and WT via physical adsorption. The optimized nanocomplex promoted the cellular uptake and showed remarkable efficacy to enhance the secreting of Th1-cytokines. This multi-functional nanocomplex system may allow effective targeting-codelivery of multi-hydrophobic drugs and be a promising subunit vaccine candidate as a potential prevention action of tumor., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The launched hepatitis B vaccine could induce powerful antibodies, whereas it failed to improve potent cellular immune responses due to that the Th2-type response-induced aluminum adjuvant was adopted. Here, to target antigen-presenting cells under the epidermis and induce potent cellular and humoral immune responses, mannose-modified poly D,L-lactide-co-glycolic acid (PLGA) was synthesized and nanoparticle (MNP)-loaded hepatitis B surface antigen (HBsAg) protein was prepared. HBsAg could be slowly released and highly presented to lymphocytes which facilitated to produce long-lasting immunity based on characters of PLGA. In vitro uptake test results showed that MNPs could enhance internalization in bone marrow-derived dendritic cells (BMDCs) and RAW 264.7 cells. Subcutaneous delivery of MNPs into mice kept humoral immune and strengthened cellular immune responses. Experimental results indicated that MNPs showed significantly modified properties compared with parental PLGA nanoparticles. Thus, the obtained MNPs could be a promising vehicle for hepatitis B vaccine delivery.