Modular Nanodevices for Creation of Smart Adaptable Vaccine Delivery Vehicles
Tarek M. Fahmy Dept. of Biomedical Engineering, Yale University
Several key variables are needed in the design of effective vaccines (Figure 1). The first variable is the form of the antigen itself. A second necessary component of a vaccine involves potentiating or stimulating the innate and adaptive arms of the immune system to the antigen subunit. Finally, to affect optimal stimulation to a given antigen a formulation is needed that delivers the correct amount of antigen in a repetitive or sustained fashion, to the appropriate immune cells and to the appropriate compartments within those cells.
SUMMARY
We describe a generalizable “smart nanoparticle” vaccine delivery system using a simple, modular approach that can be easily adapted to the requirements of a particular vaccine. Our approach tethers individual DC recognition, Transepithelial and protective elements into the surface of the nanodevice constructed from biocompatible polyester poly (lactic-co-glycolic acid) (PLGA). The core of the device is loaded with antigen or elements facilitating targeted release of antigen into the correct intracellular compartments. In this work the use of biodegradable polymer nanoparticles as a platform for designing vaccines is being systematically and quantitatively explored.
OBJECTIVES
1) Engineering individual nanoparticulate recognition units that effectively target DCs.2) Examination of the uptake of the nanodevice by cultured dendritic cells and determiningthe efficacy of antigen presentation.3) Engineering nanoparticulates to transit through epithelial cell layers.4) Engineering‘smart’ protective coatings facilitating transport through low pH and corrosive environments.
Blank Particles
Dendritic cells were isolated and primed with blank nanospheres (No OVA ), unmodified OVA particles (Untargeted), LPS-modified OVA nanospheres (LPS-OVA), blank nanospheres with soluble OVA (Soluble OVA), or blank nanospheres with soluble OVA and soluble LPS (Soluble OVA +Soluble LPS) and co-cultured with splenocytes from an OT-1 transgenic mouse. IL-2 release was measured by ELISA.
Vaccination against the West Nile Virus E-Protein
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0 5 10 15 20
Days Post Challenge
% S
urvi
ving
Ani
mal
s
SubQ
Oral
No Vaccine
N=10 per groupAnimals injected with live virulent virus on day 0.
In Vivo Vaccination
Enhanced Antigen-Specific Cellular Proliferation with DC targeted nanoparticle vaccines
Proliferation of spleen cells from mice subcutaneously or orally vaccinated with ovalbumin-encapsulating nanospheres.. Isolated spleen cells were challenged with different doses of ovalbumin antigen in a plate. Nanospheres modified with LPS encapsulating OVA , nanospheres encapsulating OVA with no external modification (Untargeted ), blank particles with no OVA and no surface modification (No OVA). Mice (N=3)
SUBCUTANEOUSVACCINATION
ORALVACCINATION
LPS-OVA
Untargeted
No OVA
0.2
2.5
3.0
3.5
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5.0
0 50 100 150
Pro
life
rati
on
x10
5
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0 30 60 90 120
OVA (ug/ml)
Pro
life
rati
on
x10
5
LPS-OVA
Untargeted
No OVA
OVA Release
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0.05
0.1
0.15
0.2
0.25
0 50 100 150 200 250 300 350
Time, hr
% T
ota
l O
VA
Rel
ease
d
LPS/OVA
MINUS/OVA
Particle size was analyzed using SEM images and were found to be an average of 100-200 nm. Ovalbumin (OVA) was encapsulated as the model antigen and a release profile (insert) was deduced using a protein assay.
Targeting Dendritic Cells
LPS/Particles
Lipopolysaccharide modified nanoarpticles encapsulating a dye are preferentially internalized by dendritic cells
-50
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0 0.01 0.02 0.03 0.04 0.05 0.06
OVA Concentration (mg/ml)
IL-2
Re
lea
se
(p
g/m
l) P < 0.0035
In Vitro Vaccination
Effective Antigen-Specific T cell Proliferation in vitro with DC targeted nanoparticles
LPS-OVA
Untargeted
No OVASoluble OVA+Soluble LPS
Work supported by NSF-NIRT Award: 0609326
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