title: Comparative label-free monitoring of immunotoxin efficacy in 2D and 3D mamma carcinoma in vitro models by impedance spectroscopy.
abstract: For selective killing of tumor cells, there are many novel and promising therapeutic approaches like immunotoxins. However, on the long way to clinical application, especially in vitro approved biologicals often fail due to loss of target sensitivity and efficacy in vivo. This is mostly explained with degradation or penetration disability in vivo. Although, these problems are well known, until today, there are no in vitro systems for reliable monitoring and quantification of therapeutic efficacy in 3D tumor models and the direct comparison to results from 2D models. In this context, we developed a combined label-free impedimetric monitoring system using our self-developed planar interdigital electrode arrays and our unique microcavity array technology. Therefore, we could demonstrate the time and concentration dependent monitoring and quantification of therapeutic efficacy in a 2D and 3D mamma carcinoma model. In detail, we synthesized a novel modular immunotoxin B3(dsFv)-PE38 (B3-PE38) in which the antibody fragment and the protein toxin are polyionic linked together. We compared the efficacy of the immunotoxin B3-PE38, the toxin E8C-PE38 (PE38) and the small molecule chemotherapeutic paclitaxel. The impedimetric screening revealed the highest cytotoxicity for the immunotoxin B3-PE38 in the 2D model. More strikingly, the immunotoxin efficacy was substantially higher in the 3D model when compared to PE38 and paclitaxel even though having a considerably lower penetration capability than paclitaxel. So our novel impedimetric monitoring system offers the comparative efficacy quantification of novel therapeutics in 2D and 3D in vitro tumor models.
authors.affiliation: Center for Biotechnology and Biomedicine (BBZ), Universität Leipzig, Division of Molecular Biological-Biochemical Processing Technology, Deutscher Platz 5, 04103 Leipzig, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Poenick
authors.forename: Heinz-Georg
authors.initials: HG
authors.lastname: Jahnke
authors.forename: Marie
authors.initials: M
authors.lastname: Eichler
authors.forename: Stefan
authors.initials: S
authors.lastname: Frost
authors.forename: Hauke
authors.initials: H
authors.lastname: Lilie
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Robitzki
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001943:Breast Neoplasms / Q000628:therapy*; D002277:Carcinoma / Q000628:therapy*; D045744:Cell Line, Tumor; D058266:Dielectric Spectroscopy; D005260:Female; D006801:Humans; D007128:Immunoglobulin Fragments / Q000737:chemistry / Q000627:therapeutic use; D000922:Immunotoxins / Q000737:chemistry* / Q000627:therapeutic use; D011506:Proteins / Q000737:chemistry / Q000627:therapeutic use
chemical_list: D007128:Immunoglobulin Fragments; D000922:Immunotoxins; D011506:Proteins
keywords: 3D tumor model; Immunotoxins; Impedance spectroscopy; Interdigital electrode array; Microcavity array