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Volume 4

Nano Research & Applications

ISSN: 2471-9838

Page 72

JOINT EVENT

August 16-18, 2018 | Dublin, Ireland

Edition of International Conference on

Nanopharmaceutics and Advanced Drug Delivery

Nano Congress for

Future Advancements

Nano Congress 2018

Nano Drug Delivery 2018

August 16-18, 2018

Developing targeted liposomal vaccines

Yvonne Perrie

University of Strathclyde, UK

attern recognition receptors, including the Toll-like receptors (TLRs), are important in the induction and activation of two

critical arms of the host defense to pathogens and microorganisms; the rapid innate immune response (as characterized by

the production of Th1 cytokines and type 1 interferons) and the adaptive immune response. Through this activation, ligands

and agonists of TLRs may offer advantages as vaccine adjuvants offering enhanced immunotherapeutic efficacy. However,

incorporation or encapsulation of these TLR agonists within delivery systems, such as liposomes, would be beneficial due the

importance of local maintenance of the agonist at the site of antigen administration for optimal adjuvant activity to be achieved,

without systemic distribution throughout the host. Resiquimod is a small (water-soluble) agonist of the endosome-located

Toll-like receptor 7 (TLR7), therefore upon injection it will rapidly distribute throughout the body rather than staying at the

injection site. In this present study, resiquimod has been chemically synthesized with DSPE lipid to form a lipid=TLR agonist

conjugate before further being incorporated within the cationic liposomes composed of dimethyl dioctadecyl ammonium

bromide (DDA) and the immune-stimulatory glycolipid trehalose 6,6′-dibehenate (TDB). The liposomes formulated with and

without the conjugated TLR7 ligand displayed similar vesicle characteristics and conjugation of resiquimod resulted in strong

retention of both resiquimod, as well as adsorbing the TB subunit vaccine Ag85B-ESAT6-Rv2660c (H56). Following vaccine

delivery through the intramuscular route a depot at the site of injection was formed promoting controlled release and drainage

of delivery system and TLR agonist to the popliteal lymph node. Immunization studies have shown that this bio-distribution

profile translates into increased Th1 responses, as well as down-regulation of Th2 responses both at the spleen, injection site

and draining popliteal lymph node.

Nano Res Appl 2018, Volume 4

DOI: 10.21767/2471-9838-C3-015