Thesis

Synthesis and evaluation of targeted dendrisomes as novel gene and drug delivery systems for cancer therapy

Creator
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Awarding institution
  • University of Strathclyde
Date of award
  • 2018
Thesis identifier
  • T14920
Person Identifier (Local)
  • 201377408
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • Introduction: The co-delivery of cancer therapeutics in hybrid nanocarriers is currently being investigated in order to achieve an additive or synergistic effect in cancer therapy. The aim of this study was to synthesize and evaluate novel transferrin-bearing dendrisomes to co-deliver therapeutic DNA encoding TNF-α and doxorubicin. Dendrisomes were thus investigated in this project in vitro and in vivo for their DNA carrying abilities as well as their ability to co-deliver therapeutic DNA and an anticancer drug. The targeted dendrisomes in this project are thus aimed at ensuring a higher selective uptake intracellularly using targeting ligand transferrin. Transferrin receptors have been found to be overexpressed on most cancer cells and are thus attractive as target sites for selective receptor-mediated tumour targeting. Methods: The dendrisomes were formulated with a combination of a lipid blend incorporating non-ionic surfactants and a dendrimer via heating and probe sonication. Doxorubicin was encapsulated in the dendrisomes through probe sonication. Conjugation of transferrin to the dendrisomes was done using bifunctional cross- linking. Characterization of the dendrisomes was then carried out through techniques including, size and zeta potential measurements, TEM, DNA condensation assays, AFM. In vitro studies were also carried out using fluorescence microscopy, confocal laser scanning microscopy, gene transfection assays and anti-proliferative assay. Biodistribution and antitumour efficacy studies were also carried out using xenograft models. Results: Dendrisomes were successfully formulated that were in the nanometer range (less than 500 nm). Some were neutral, and some were positively charged as obtained from zeta potential readings. TEM pictures showed that these novel dendrisomes were spherical. DNA condensation and doxorubicin encapsulation efficiency were respectively above 75% and 95% and demonstrated the ability of the dendrisomes to carry both DNA and drug. DNA encoding β-galactosidase was successfully expressed in A431, B16F10-Luc-G5 and T98G cancer cells. Cellular uptake experiments demonstrated that the novel dendrisomes caused increase in doxorubicin and DNA intracellular uptake. Anti-proliferative efficacy was improved following treatment with dendrisomes co-delivering DNA encoding TNF-α and doxorubicin, compared to that observed with doxorubicin alone or DNA encoding TNF-α alone with synergism observed in B16F10-Luc-G5 cells that were treated with transferrin bearing, doxorubicin encapsulated DSOLm dendrisomplexes. Conclusion: In conclusion, this project is the first demonstration of transferrin-targeted novel dendrisomes being complexed to therapeutic plasmid DNA encoding TNF-α for gene delivery while concurrently entrapping anticancer drug doxorubicin for cancer therapy. The novel targeted dendrisomes were shown to have the capacity to co-deliver therapeutic plasmid DNA encoding TNF- α and anticancer drug doxorubicin to cancer cells in vitro and in vivo, thus leading to increased anti-proliferative effect in vitro and slightly increased therapeutic efficacy at the doses used in vivo in selected cancer cell lines and solid tumours overexpressing transferrin respectively.
Advisor / supervisor
  • Dufes, Christine
  • Halbert, Gavin
Resource Type
Note
  • This thesis was previously held under moratorium from 13/08/2018 to 15/08/2023
DOI
Date Created
  • 2018
Former identifier
  • 9912620291202996
Funder

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