GENERAL OVERVIEW:
Vaxiion's proprietary minicell-based targeted delivery technologies are capable of the simultaneous delivery of a host of different molecules with therapeutic value including DNA, RNA, proteins, and small-molecule drugs to targeted cells of choice. Minicells are small, semi-spherical, bacterial nano-particles (shown at the left are minicells budding off of the polar region of a parental E. coli cell expressing green flourescent protein) that contain all of the components of the parental bacteria, except chromosomes. Without chromosomes, they cannot divide and are non-infectious, making them highly suitable for development as  in vivo delivery products. Vaxiion's minicell-producing bacteria have been engineered to mass produce minicells that preferentially target and deliver molecules to specific cancer cell types.  The development of the minicell production platform serves as the cornerstone of Vaxiion’s technology, enabling the company to engineer a long list of novel targeted delivery products.  

OUR MINICELL-VEHICLE PLATFORM:
Vaxiion's proprietary targeted-delivery platform has been engineered to address several regulatory and manufacturing requirements while simultaneously reducing the eventual cost of the product. The bacterial strains used in the platform are genetically engineered such that they do not contain any antibiotic-resistance gene markers, generate significantly higher amounts of minicells (25X over other previous reported strains), and are amenable to ultra-purification by activation of Vaxiion’s proprietary MSX-3 System™, a multifunctional suicide mechanism. This unique and inducible system causes the minicell-producing parental cells to (i) enhance minicell production, (ii) "commit suicide" by a novel mechanism that does not depend on cell lysis, and (iii) enter into an irreversible and uniform filamentous phenotype, making them perfectly suited for conventional size-based filtration methodologies. Using these novel technologies, Vaxiion has produced as many as 10¹⁷ minicells in a single production run with zero parental cell contamination.


HOW WE TARGET SPECIFIC CANCER CELLS:
Targeting is achieved through the expression and minicell-surface display of fusion protein-based antibody fragments specific for tumor selective antigens such as EGFR, Her-2/neu, and CD-166 amongst others.  Vaxiion's proprietary approach to coupling antibodies to the surfaces of minicells also includes the use of conventional chemical coupling methodologies and the use of bi-specific antibodies or antibody complexes.


LOADING MINICELLS:
Vaxiion has developed two methods of loading minicells with the payload(s) of choice. In one approach, proteins and nucleic acids are produced by the minicell-producing parental strain prior to the induction of the minicell phenotype such that the protein(s) and/or nucleic acids (plasmid DNA or RNA) are encapsulated by the  minicells as they bud off. Alternatively, following the ultra-purification of empty minicells (or protein/DNA encapsulating minicells), small molecules, including cytotoxic drugs and imaging agents, are loaded into  minicells by simple co-incubation in a high concentration of the small molecule. 

Vaxiion's propriatary minicell producing strain coexpressing green flourescent protein (above).



Ultrapure minicells encapsulating soluble green flourescent protein (above).




Scanning Electron Micrograph of minicells and filamentous parental cells produced using the MSX-3 System^TM (above).