title: The structure-dependent toxicity, pharmacokinetics and anti-tumour activity of HPMA copolymer conjugates in the treatment of solid tumours and leukaemia.
abstract: Polymer drug carriers that are based on N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers have been widely used in the development and synthesis of high-molecular-weight (HMW) drug delivery systems for cancer therapy. In this study, we compared linear (Mw ~27kDa, Rh ~4nm) and non-degradable star (Mw ~250kDa, Rh ~13nm) HPMA copolymer conjugates bearing anthracycline antibiotic doxorubicin (DOX) bound via pH-sensitive hydrazone bond. We determined the in vitro and in vivo toxicity of both conjugates and their maximum tolerated dose (MTD). We also compared their anti-tumour activity in mouse B-cell leukaemia (BCL1) and a mouse T-cell lymphoma (EL4) model. We found that MTD was higher for the linear conjugate (85mgDOX/kg) and lower for the star conjugate (22.5mgDOX/kg). An evaluation of the intestinal barrier integrity using FITC-dextran as a gut permeability tracer proved that no pathology was caused by the MTD of either conjugate. However, free DOX showed some damage to the gut barrier. The therapy of BCL1 leukaemia by both of the polymeric conjugates using the MTD or its fraction (i.e., equitoxic dosage) showed better results in the case of the star conjugate. On the other hand, treatment of EL4 lymphoma seemed to be more efficient when the linear conjugate was used. We suppose that the anti-cancer treatment of solid tumours and leukaemias requires different types of drug conjugates. We hypothesise that the most suitable HPMA copolymer-DOX conjugate for the treatment of solid tumours should have an HMW structure with increased Rh that would be stable for three to four days after the conjugate administration and then rapidly disintegrate in the short polymer chains, which are excretable from the body by glomerular filtration. On the other hand, the treatment of leukaemia requires a drug conjugate with a long circulation half-life. This would provide an active drug, whilst slowly degrading to excretable fragments.
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic. Electronic address: barbora.tomalova@biomed.cas.cz.
authors.forename: Barbora
authors.initials: B
authors.lastname: Tomalova
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic. Electronic address: sirova@biomed.cas.cz.
authors.forename: Milada
authors.initials: M
authors.lastname: Sirova
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic. Electronic address: rossmannp@seznam.cz.
authors.forename: Pavel
authors.initials: P
authors.lastname: Rossmann
authors.affiliation: Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 16206 Prague, Czech Republic. Electronic address: pola@imc.cas.cz.
authors.forename: Robert
authors.initials: R
authors.lastname: Pola
authors.affiliation: Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 16206 Prague, Czech Republic. Electronic address: strohalm@imc.cas.cz.
authors.forename: Jiri
authors.initials: J
authors.lastname: Strohalm
authors.affiliation: Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 16206 Prague, Czech Republic. Electronic address: chytil@imc.cas.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Chytil
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic. Electronic address: viktor.cerny@biomed.cas.cz.
authors.forename: Viktor
authors.initials: V
authors.lastname: Cerny
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic. Electronic address: tomala@biomed.cas.cz.
authors.forename: Jakub
authors.initials: J
authors.lastname: Tomala
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic. Electronic address: kabesova@biomed.cas.cz.
authors.forename: Martina
authors.initials: M
authors.lastname: Kabesova
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic. Electronic address: rihova@biomed.cas.cz.
authors.forename: Blanka
authors.initials: B
authors.lastname: Rihova
authors.affiliation: Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 16206 Prague, Czech Republic. Electronic address: ulbrich@imc.cas.cz.
authors.forename: Karel
authors.initials: K
authors.lastname: Ulbrich
authors.affiliation: Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 16206 Prague, Czech Republic. Electronic address: etrych@imc.cas.cz.
authors.forename: Tomas
authors.initials: T
authors.lastname: Etrych
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic. Electronic address: makovar@biomed.cas.cz.
authors.forename: Marek
authors.initials: M
authors.lastname: Kovar
mesh_terms: D000178:Acrylamides / Q000737:chemistry* / Q000493:pharmacokinetics / Q000627:therapeutic use / Q000633:toxicity; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use / Q000633:toxicity; D001853:Bone Marrow / Q000187:drug effects / Q000473:pathology; D045744:Cell Line, Tumor; D050091:Dendrimers / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use / Q000633:toxicity; D004317:Doxorubicin / Q000737:chemistry* / Q000493:pharmacokinetics / Q000627:therapeutic use / Q000633:toxicity; D004337:Drug Carriers / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use / Q000633:toxicity; D005260:Female; D007413:Intestinal Mucosa / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000473:pathology; D020714:Maximum Tolerated Dose; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D009369:Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D013154:Spleen / Q000187:drug effects / Q000473:pathology; D013329:Structure-Activity Relationship
chemical_list: D000178:Acrylamides; D000903:Antibiotics, Antineoplastic; D050091:Dendrimers; D004337:Drug Carriers; C104700:PAMAM Starburst; C482378:N-(2-hydroxypropyl)methacrylamide co-polymer-doxorubicin conjugate; D004317:Doxorubicin
keywords: Anti-tumour activity; Doxorubicin; HPMA; Structure; Toxicity