Sugar-modified PPI dendrimers as carriers of anti-leukemia drugs

Barbara Klajnert-Maculewicz

Department of General Biophysics

University of Lodz

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Linear polymer1930s

Branched polymer1960s

Dendrimer1980s

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dendrimer - gr. dendronarborol - lat. arborcascade molecule

D. Tomalia

F. Vögtle

G. Newcome

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dendrimer - gr. dendronarborol - lat. arborcascade molecule

dendrimer

cascade molecule

arborol

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• globular shape

• monodispersity

• big dimensions

• high reactivity

• good solubility

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DRUG DELIVERY

GENE CARRIERS ANTI-PRION ACTIVITY

ANTI-MICROBIAL ACTIVITY

ANTI-HIV ACTIVITY

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Dendrimers as drug carriers

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• prolonging the circulation time in blood

• protecting unstable drugs from the environment

• enhancing solubility of poorly soluble drugs

• achieving a controlled release and tissue targeting

• one molecule of dendrimer is capable to carry drugs at high density

• slower release than for a free drug

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Physiological nucleoside analogues (NAs)

Cytarabine is used to treat different forms of leukemia, including acute and chronic myelogenous (AML and CML) and acute lymphocytic leukemia (ALL).

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arabinose - cytosine

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Drug resistance mechanisms

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Conventional therapy with ara-C

Drug resistance

Dendrimers as carriers of ara-CTP

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Maltose-modified PPI dendrimer

PPI-OS-Mal G5 (approx. 30% maltose)

Dr. Dietmar AppelhansSynthesis: Fischer et al. Biomacromolec. 10 (2009) 1314-1325

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Advantages of sugar modification

non-hemolytical 1, 2

do not cause platelets aggregation 2

low toxicity in vitro 3

low toxicity in vivo 4

retained activity 1, 5, 6

1. B. Klajnert et al. Chem. Eur. J. 14 (2008) 7030-70412. B. Ziemba et al. J. Biomed. Mater. Res. A. 100 (2012) 28703. A. Janaszewska et al. New J. Chem. 36 (2012) 428-4374. B. Ziemba et al. J. Biomed. Mater. Res. A 99 (2011) 261-2685. M. Fischer et al. Biomacromolecules 11 (2010) 1314-13256. M. Ciołkowski et al. Colloid Surface B 95 (2012) 103-108

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+

• dendrimer and ara-CTP form complexes (ara-CTP/dendrimer=10)• complexes are stable• ara-CTP is protected against enzymatic degradation

ara-CTP

complexes:

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dephosphorylation

alkaline phosphatase

ATP adenosine

A. Szulc et al. New J. Chem. 36 (2012) 1610-1615

Protection agaist enzymatic degradation – FPLC method

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free ATPbound ATP

A. Szulc et al. New J. Chem. 36 (2012) 1610-1615

Protection agaist enzymatic degradation – FPLC method

A254 nm

retention time = 13 min

retention time = 19 min

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free ATPbound ATP

adenosine

retention time = 29 min

A. Szulc et al. New J. Chem. 36 (2012) 1610-1615

Protection agaist enzymatic degradation – FPLC method

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adenosine

retention time = 29 min

system PPI-m G5 + adenosine no complex!

A. Szulc et al. New J. Chem. 36 (2012) 1610-1615

Protection agaist enzymatic degradation – FPLC method

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no free ATPbound ATP

adenosineretention time = 29 minred line:

system PPI-m G5 + ATP +alkaline phosphatase

A. Szulc et al. New J. Chem. 36 (2012) 1610-1615

Protection agaist enzymatic degradation – FPLC method

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bound ATP

red line:system PPI-m G5 + ATP +alkaline phosphatase

26% of complexed ATPwas degraded.

A. Szulc et al. New J. Chem. 36 (2012) 1610-1615

Protection agaist enzymatic degradation – FPLC method

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1301

human acute lymphoblastic T cells

leukemia cell line: control cells:

PBMC

peripheral blood mononuclear cells

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Internalization of dendrimers into cells

fluorescein (FITC)

Flow cytometry

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Internalization of dendrimers into 1301 cells

fluorescein (FITC)

Confocal microscopy

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Cytotoxicity Alamar Blue assay

Cytotoxicity test with resazurin - in live cells it is reduced to resorufin:

exc=530 nmem=590 nm

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Dendrimer cytotoxicity

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Cytotoxicity - 1301 48h

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Cytotoxicity - 1301 48h

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Cytotoxicity - 1301 48h

*

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Cytotoxicity - 1301 72h

** * *

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Cytotoxicity - PBMC 48h

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Cytotoxicity - PBMC 72h

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Inhibitor of nucleoside transporters

NBMPR - nitrobenzylmercaptopurine

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1301

48 h 72 h

Inhibitors of NT in

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1301

Anti-leukemia activity:

> >

>> !

1.

2.

3.

CONCLUSIONS:

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Acknowledgements

Dr. Dietmar AppelhansLeibniz-Institutefür PolymerforschungDresden e.V. Germany

Aleksandra Szulc, M.Sc.PhD studentUniversity of LodzPoland

TEAM project „Biological properties and biomedical applications of dendrimers”

BIODENDRIMER 2014

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Thank you.

BIODENDRIMER 2014

Faculty of Biology and Environmental Protection,Lodz, Poland