Functionalized Nanomaterials for Vaccine Development:

Targeted Delivery Vesicles (TDVs™)—Stable and Versatile Alternatives to Liposomes

Presentation of surface antigens to the immune system is the critical step in the development of vaccines against viral and bacterial pathogens.  Although many strategies have been developed in recent years, a number of serious challenges remain in vaccine development, including

  • identification and purification of surface antigens
  • synthesis of the polyvalent vaccine candidates
  • control of the surface density of antigen presentation in the vaccine
  • formulation of polyvalent vaccine candidates
  • long term storage of vaccines
  • administration of vaccine by non-traditional methods (intranasal, transdermal, etc.)

New technologies are required to overcome these shortcomings of current vaccine technologies. Liposomal preparations are widely used for drug delivery due to their ability of either solubilize highly lipophilic drugs (solubility in serum) or to protect the drug from biological process that result in removal of the drug from serum, and extension of liposomal technologies to vaccine production has been investigated.  However, liposome technology has several weaknesses that limit its utility in vaccine production: short shelf life (especially in liquid form), short in vivo circulation time resulting from thermodynamic instability of liposomes in biological media, rapid release of solutes, and the high cost of liposome components.

SD Nanosciences’s novel functionalized vesicle technology overcomes the limitations of liposomal methods and has been shown to be capable of producing polyvalent vaccine rapidly, in high yield, and with outstanding reproducibility. The superior stability and versatile physiochemical properties of our patent-pending technology, Targeted Delivery Vesicles—TDV™—offers a robust, flexible and affordable technology for the production of vaccines.   The major advances include

  •  ability to extract surface antigens from pathogens without extensive purification
  •  ability to control antigen presentation and density in the vesicle leaflet
  • efficient and inexpensive manufacturing of vaccine by chemical methods
  • efficient and inexpensive sterilization methods
  • long term storage at room temperature

The new vesicle technology for vaccine production.

Unlike liposomes were vesicle preparations require physical manipulation such as sonication or extrusion to prevent the formation of large, multilamellar structures, SD Nanosciences has developed methods to use spontaneously formed, thermodynamically stable surfactant vesicles (TDVs) as a tool for vaccine production. TDVs are formed from a mixture of cationic and anionic surfactants that spontaneously form unilamellar, thermodynamically stable vesicles with a diameter of 150-200 nm.  The vesicles can be "loaded" with cargo and stored for months as either a sterile liquid at room temperature or a lyophilized powder.  Surface functionalization of the vesicle leaflet with a variety of bioconjugates including complex carbohydrates, peptides, nucleic acids, and antibodies has been achieved and control of the bioconjugate (or antigen) presentation in the leaflet can be controlled by the patented technology.

TDV vesicle production benefits

  • Spontaneously form unilamellar vesicles with a diameter of 150-200 nm
  • TDVs can be formulated as either cationic or anionic vesicles
  • TDV form spontaneously when surfactant concentrations are optimal
  • TDV components are available as commodities and are inexpensive
  • TDV components are approved by the FDA for use in humans

TDV novel features/benefits including

  •  Thermodynamically stable at room temperature for months and can be heated to 65 °C without decomposition
  • TDVs will preferentially and efficiently encapsulate charged molecules
  • Can be formulated with biomolecules in the leaflet for targeting applications
  • TDV components are already approved for use in humans
  • Electrostatic sequestration of solutes in vesicles and vesicle-based separations
  • Surface functionalization of catanionic vesicles with carbohydrate moieties to interact with proteins in solution and at cell surfaces
  • Extraction of surface antigens can be used to produce "artificial pathogens"
  • Conclusions
  • TDVs are a novel platform for vaccine production
  • TDVs are a novel platform for targeted drug delivery

 

For more information, please contact

Philip DeShong  

President & Chief Technology Officer                              
SD Nanosciences, Inc.
4467 Technology Dr.
College Park, MD 20742
and
Professor                                                                               
Department of Chemistry & Biochemistry                                  
University of Maryland
College Park, MD 20742

deshong@umd.edu

(301) 405-1892