Killing cancer cells by targeted drug-carrying phage nanomedicines

Department of Molecular Microbiology and Biotechnology, The George S, Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv 69978, Israel.
BMC Biotechnology (Impact Factor: 2.03). 02/2008; 8(1):37. DOI: 10.1186/1472-6750-8-37
Source: PubMed


Systemic administration of chemotherapeutic agents, in addition to its anti-tumor benefits, results in indiscriminate drug distribution and severe toxicity. This shortcoming may be overcome by targeted drug-carrying platforms that ferry the drug to the tumor site while limiting exposure to non-target tissues and organs.
We present a new form of targeted anti-cancer therapy in the form of targeted drug-carrying phage nanoparticles. Our approach is based on genetically-modified and chemically manipulated filamentous bacteriophages. The genetic manipulation endows the phages with the ability to display a host-specificity-conferring ligand. The phages are loaded with a large payload of a cytotoxic drug by chemical conjugation. In the presented examples we used anti ErbB2 and anti ERGR antibodies as targeting moieties, the drug hygromycin conjugated to the phages by a covalent amide bond, or the drug doxorubicin conjugated to genetically-engineered cathepsin-B sites on the phage coat. We show that targeting of phage nanomedicines via specific antibodies to receptors on cancer cell membranes results in endocytosis, intracellular degradation, and drug release, resulting in growth inhibition of the target cells in vitro with a potentiation factor of >1000 over the corresponding free drugs.
The results of the proof-of concept study presented here reveal important features regarding the potential of filamentous phages to serve as drug-delivery platform, on the affect of drug solubility or hydrophobicity on the target specificity of the platform and on the effect of drug release mechanism on the potency of the platform. These results define targeted drug-carrying filamentous phage nanoparticles as a unique type of antibody-drug conjugates.

Download full-text


Available from: Iftach Yacoby
  • Source
    • "ystem that functionalizes short Ff phage - derived nanorods . It further demonstrates one application for use in dipstick assays . Given a large range of publications describing applications where Ff virions are used , including the templates for assembly of inor - ganic structures , diagnostics , tissue templating , imaging , and drug targeting ( Bar et al . , 2008 ; Petrenko , 2008 ; Lee et al . , 2009 ; Souza et al . , 2010 ; Chung et al . , 2011 ; Dang et al . , 2013 ; Bernard and Francis , 2014 ; Oh et al . , 2014 ) , Ff - nano as short non - viral functionalized particles will likely find many diverse applications ."
    [Show abstract] [Hide abstract]
    ABSTRACT: F-specific filamentous phage of Escherichia coli (Ff: f1, M13 or fd) are long thin filaments (860 nm x 6 nm). They have been a major workhorse in display technologies and bionanotechnology; however, some applications are limited by the high length-to-diameter ratio of Ff. Furthermore, use of functionalized Ff outside of laboratory containment is in part hampered by the fact that they are genetically modified viruses. We have now developed a system for production and purification of very short functionalized Ff-phage-derived nanorods, named Ff-nano, that are only 50 nm in length. In contrast to standard Ff-derived vectors that replicate in E. coli and contain antibiotic-resistance genes, Ff-nano are protein DNA complexes that cannot replicate on their own and do not contain any coding sequences. These nanorods show an increased resistance to heating at 70 °C in 1 % SDS in comparison to the full-length Ff phage of the same coat composition. We demonstrate that functionalized Ff-nano particles are suitable for application as detection particles in sensitive and quantitative “dipstick” lateral flow diagnostic assay for human plasma fibronectin.
    Full-text · Article · Apr 2015 · Frontiers in Microbiology
  • Source
    • "By the streptavidin crosslinking methods described above small therapeutic drug molecules may be incorporated into the matrix. Furthermore the link to the phage can be engineered to be dependent on enzymatic cleavage [68, 81] so that the delivered molecules are released only when they are sequestered by the cell activity. Therapeutic genetic material can be incorporated into the phage DNA and carried within the phage capsule for specific delivery to the cells via receptor uptake [37]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Controlling structural organization and signaling motif display is of great importance to design the functional tissue regenerating materials. Synthetic phage, genetically engineered M13 bacteriophage has been recently introduced as novel tissue regeneration materials to display a high density of cell-signaling peptides on their major coat proteins for tissue regeneration purposes. Structural advantages of their long-rod shape and monodispersity can be taken together to construct nanofibrous scaffolds which support cell proliferation and differentiation as well as direct orientation of their growth in two or three dimensions. This review demonstrated how functional synthetic phage is designed and subsequently utilized for tissue regeneration that offers potential cell therapy.
    Full-text · Article · May 2014 · Mediators of Inflammation
  • Source
    • "Unlike drug conjugated to an antibody, a large amount of anticancer drug can be easily conjugated by chemical linking to pVIII which exists 2,700 copies as major-phage-coated proteins per a phage particle [21]. Anticancer-drug-conjugated bacteriophages have been used successfully with a potentiator factor of over 1,000 compared to free drug [22]. The studies of phages as targeted drug carriers were mostly in vitro. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Major histocompatibility complex class I chain-related gene A (MICA) is an NKG2D ligand that is over-expressed under cellular stress including cancer transformation and viral infection. High expression of MICA in cancer tissues or patients' sera is useful for prognostic or follow-up markers in cancer patients. In this study, phage display technology was employed to improve antigen-binding activities of anti-MICA monoclonal antibodies (WW2G8, WW6B7, and WW9B8). The 12 amino acid residues in the complementarity determining regions (CDRs) on the V domain of the heavy chain CDR3 (HCDR3) of these anti-MICA antibodies were modified by PCR-random mutagenesis, and phages displaying mutated anti-MICA Fab were constructed. After seven rounds of panning, five clones of phages displaying mutant anti-MICA Fab which exhibited 3-7-folds higher antigen-binding activities were isolated. Two clones of the mutants (phage-displayed mutant Fab WW9B8.1 and phage-displayed mutant Fab WW9B8.21) were confirmed to have antigen-binding specificity for cell surface MICA proteins by flow cytometry. These phage clones are able to recognize MICA in a native form according to positive results obtained by indirect ELISA and flow cytometry. Thus, these phage particles could be potentially used for further development of nanomedicine specifically targeting cancer cells expressing MICA proteins.
    Full-text · Article · Nov 2012 · BioMed Research International
Show more