Department of Biomedicinal Polymers

Head: Prof. Karel Ulbrich, DSc
(phone +420-296 809 231, e-mail ulbrich@imc.cas.cz)

Research

Research activity of the Department is focused on the synthesis of hydrophilic polymers, the study of interactions between synthetic and biologically active natural macromolecules and the use of conjugates of synthetic and natural macromolecules in designing new drug-release and drug-delivery systems. The main research topics are as follows.

Polymers and polymer systems for site-specific drug delivery

An exciting new class of antitumour agents based on conjugates of water-soluble polymers with cancerostatics and antibodies designed for tumour-specific drug delivery is being developed. The following drug carrier systems are studied:

• soluble polymer carriers containing both drug and targeting moieties (antibody) bound to the polymer by means of biodegradable oligopeptide side chains;
• targetable star polymers containing a targeting moiety in the center and poly[N-(2-hydroxypropyl)methacrylamide] arms bearing drug;
• biodegradable polymer carriers based on block copolymers of poly(ethylene glycol)s facilitating site-specific delivery of anti-cancer drugs.

Potential uses of hydrophilic polymers for delivery of proteins and enzymes are also studied.

Polymer systems for gene therapy

Synthesis of polycations and their block copolymers with hydrophilic or hydrophobic polymers as well as formation of their micellar complexes with DNA are extensively studied. Such biocompatible polymer constructs are designed to facilitate cytoplasmic DNA delivery and to provide a real opportunity of developing polymer therapeutics for gene therapy.

Hydrogels for controlled drug release

New hydrophilic, hydrolytically biodegradable gels based on crosslinked polymers and copolymers are being studied as suitable materials for development of new drug release systems. Problems related to combination of water-soluble targetable polymer drugs with hydrophilic biodegradable gels are also dealt with.

Major topics studied in the Department in 2000 concerned development of water-soluble drug carrier systems designed for site-specific therapy and the study of polycation/DNA complexes suitable as vectors for specific gene delivery. New biodegradable water-soluble polymer drug carriers were developed and used for the synthesis of the antibody-targeted anti-cancer drugs based on biodegradable poly(ethylene glycol) block copolymers. These polymer drugs exhibited a significant anti-cancer activity in model tumours in vivo in mice (inhibition of tumour growth, prolongation of the mean survival time) and, at the same time, reduced side toxicity. Two methods of modification of therapeutically active enzymes with synthetic hydrophilic polymers were developed and used for preparation of polymer conjugates of bovine seminal ribonuclease. The results of biological evaluation of the conjugates demonstrated significant protection by the polymer of the enzyme against biodegradation and proved a high potential of the conjugates in the treatment of human melanoma in mice.

Send your comments to:
ulbrich@imc.cas.cz
Last modified: 29.04.2003