title: Bacterial ghosts (BGs)--advanced antigen and drug delivery system.
abstract: Bacterial ghosts (BGs) are empty bacterial envelopes of Gram-negative bacteria produced by controlled expression of cloned gene E, forming a lysis tunnel structure within the envelope of the living bacteria. BGs are devoid of cytoplasmic content and possess all bacterial bio-adhesive surface properties in their original state while not posing any infectious threat. BGs are ideally suited as an advanced drug delivery system (ADDS) for toxic substances in tumor therapy. The inner space of BGs can be loaded with either single components or combinations of peptides, drugs or DNA which provides an opportunity to design new types of (polyvalent) drug delivery vehicles. Uptake of BGs loaded with Doxorubicin (Dox) by CaCo2 cells led to effective Dox release from endo-lysosomal compartments and accumulation in the nucleus. Viability and proliferative capacity of the cells were significantly decreased (2-3 orders of magnitude) after internalization of Dox loaded BGs as compared to cells incubated with free Dox. The same effect was observed with leukemia cells. Melanoma cells also revealed a high capability to internalize BGs. These results indicate that BGs are able to target a range of types of cancer. BGs have also been investigated as DNA delivery vectors. Studies show DNA loaded BGs are efficiently phagocytosed and internalized by both professional APCs and tumor cells with up to 82% of cells expressing the plasmid-encoded reporter gene. Our studies with BGs as an ADDS system contribute (i) to optimize drug delivery for the treatment of cancer; (ii) define specific conditions for selection and preparation of BG formulations; (iii) and provide a background for the clinical application of BGs in cancer therapy.
authors.affiliation: BIRD-C GmbH&CoKEG, Kritzendorf, Austria. pavol.kudela@bird-c.at
authors.forename: Pavol
authors.initials: P
authors.lastname: Kudela
authors.forename: Verena Juliana
authors.initials: VJ
authors.lastname: Koller
authors.forename: Werner
authors.initials: W
authors.lastname: Lubitz
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D018938:Caco-2 Cells; D019496:Cancer Vaccines; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000008:administration & dosage; D004317:Doxorubicin / Q000494:pharmacology; D016503:Drug Delivery Systems; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006090:Gram-Negative Bacteria / Q000276:immunology*; D006801:Humans; D007938:Leukemia / Q000188:drug therapy; D008545:Melanoma / Q000188:drug therapy; D010587:Phagocytosis
chemical_list: D000970:Antineoplastic Agents; D019496:Cancer Vaccines; D004317:Doxorubicin; D004247:DNA