Nasal delivery of H5N1 avian influenza vaccine formulated with GenJet™ or in vivo-jetPEI® induces enhanced serological, cellular and protective immune responses

Progress in Treatment and Diagnostics of Infectious Disease with Polymers

In this era of advanced technology and innovation, infectious diseases still cause significant morbidity and mortality, which need to be addressed. Despite overwhelming success in the development of vaccines, transmittable diseases such as tuberculosis and AIDS remain unprotected, and the treatment is challenging due to frequent mutations of the pathogens. Formulations of new or existing drugs with polymeric materials have been explored as a promising new approach. Variations in shape, size, surface charge, internal morphology, and functionalization position polymer particles as a revolutionary material in healthcare. Here, an overview is provided of major diseases along with statistics on infection and death rates, focusing on polymer-based treatments and modes of action. Key issues are discussed in this review pertaining to current challenges and future perspectives.

Exosome-mediated delivery of RNA and DNA for gene therapy

Gene therapy promises to revolutionize biomedicine and personalized medicine by modulating or compensating the expression of abnormal genes. The biggest obstacle for clinical application is the lack of an effective, non-immunogenic delivery system. We show that bovine colostrum exosomes and polyethyleneimine matrix (EPM) delivers short interfering RNA (siRNA) or plasmid DNA (pDNA) for effective gene therapy. KRAS, a therapeutic focus for many cancers, was targeted by EPM-delivered KRAS siRNA (siKRAS) and inhibited lung tumor growth (>70%) and reduced KRAS expression (50%-80%). Aberrant p53 is another therapeutic focus for many cancers. EPM-mediated introduction of wild-type (WT) p53 pDNA (pcDNA-p53) resulted in p53 expression in p53-null H1299 cells in culture, subcutaneous lung tumor, and tissues of p53-knockout mice. Additionally, chemo-sensitizing effects of paclitaxel were restored by exogenous WT p53 in lung cancer cells. Together, this novel EPM technology represents an effective 'platform' for delivery of therapeutic nucleic acids to treat human disease.

Enhanced gene transfection efficiency by low-dose 25 kDa polyethylenimine by the assistance of 1.8 kDa polyethylenimine

Gene therapy is a promising strategy for treatments of various diseases. Efficient and safe introduction of therapeutic genes into targeted cells is essential to realize functions of the genes. High-molecular-weight polyethylenimines (HMW PEIs) including 25 kDa branched PEI and 22 kDa linear PEI are widely used for in vitro gene transfection. However, high-gene transfection efficiency is usually accompanied with high cytotoxicity, which hampers their further clinical study. On the contrary, low-molecular-weight polyethylenimines (LMW PEIs) such as 1.8 kDa PEI and 800 Da PEI show good biocompatibility but their applications are limited by the poor DNA condensation capability. In this study, we find that 1.8 kDa PEI, but not 800 Da PEI combined with low-dose 25 kDa PEI could significantly promote gene transfection with low cytotoxicity. Plasmids encoding enhanced green fluorescence protein (EGFP) were delivered by the combined PEI and gene transfection efficiency was evaluated by microscopic observation and flow cytometry. Parameters including concentrations of 25 kDa PEI and 1.8 kDa PEI and preparation ways were further optimized. This study presents an efficient and safe combined PEI-based non-viral gene delivery strategy with potential for in vivo applications.

Vaccination With a Single Consensus Envelope Protein Ectodomain Sequence Administered in a Heterologous Regimen Induces Tetravalent Immune Responses and Protection Against Dengue Viruses in Mice

The development of a safe and effective tetravalent dengue vaccine that elicits protection against all dengue virus (DENV) serotypes is urgently needed. The consensus sequence of the ectodomain of envelope (E) protein of DENV (cE80) has been examined as an immunogen previously. In the current study, a cE80 DNA (D) vaccine was constructed and evaluated in conjunction with the cE80 protein (P) vaccine to examine whether both vaccines used together can further improve the immune responses. The cE80 DNA vaccine was administrated using either a homologous (DNA alone, DDD) or heterologous (DNA prime-protein boost: DDP or DPP) regimen, and evaluated for immunogenicity and protective efficacy in mice. Among the three DNA-based immunization regimens tested, DDP immunization is the optimal immunization regimen that elicited the greatest systemic immune response and conferred protection against all four DENV serotypes. This work provides innovative ideas for the development of consensus E-based dengue vaccines and the testing of optimal immunization regimens.