title: High content analysis of cytotoxic effects of pDMAEMA on human intestinal epithelial and monocyte cultures.
abstract: Poly(2-(dimethylamino ethyl)methacrylate) (pDMAEMA) is a cationic polymer with potential as an antimicrobial agent and as a non-viral gene delivery vector. The aim was to further elucidate the cytotoxicity of a selected pDMAEMA low molecular weight (MW) polymer against human U937 monocytes and Caco-2 intestinal epithelial cells using a novel multi-parameter high content analysis (HCA) assay and to investigate histological effects on isolated rat intestinal mucosae. Seven parameters of cytotoxicity were measured: nuclear intensity (NI), nuclear area (NA), intracellular calcium ([Ca(2+)]i), mitochondrial membrane potential (MMP), plasma membrane permeability (PMP), cell number (CN) and phospholipidosis. Histological effects of pDMAEMA on excised rat ileal and colonic mucosae were investigated in Ussing chambers. Following 24-72 h exposure, 25-50 microg/ml pDMAEMA induced necrosis in U937 cells, while 100-250 microg/ml induced apoptosis in Caco-2. pDMAEMA increased NA and NI and decreased [Ca(2+)]i, PMP, MMP and CN in U937 cells. In Caco-2, it increased NI and [Ca(2+)]i, but decreased NA, PMP, MMP and CN. Phospholipidosis was not observed in either cell line. pDMAEMA (10 mg/ml) did not induce any histological damage on rat colonic tissue and only mild damage to ileal tissue following exposure for 60 min. In conclusion, HCA reveals that pDMAEMA induces cytotoxicity in different ways on different cell types at different concentrations. HCA has potential for high throughput toxicity screening in drug formulation programmes.
authors.affiliation: UCD School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland.
authors.forename: Lee-Anne B
authors.initials: LA
authors.lastname: Rawlinson
authors.forename: Peter J
authors.initials: PJ
authors.lastname: O'Brien
authors.forename: David J
authors.initials: DJ
authors.lastname: Brayden
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001681:Biological Assay; D018938:Caco-2 Cells; D002118:Calcium / Q000378:metabolism; D002452:Cell Count; D002463:Cell Membrane Permeability / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007082:Ileum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008689:Methacrylates / Q000633:toxicity*; D008970:Molecular Weight; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009757:Nylons / Q000633:toxicity*; D051381:Rats
chemical_list: D008689:Methacrylates; D009757:Nylons; C407037:poly(2-(dimethylamino)ethyl methacrylate); D002118:Calcium