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Published on: October 10, 2013
Drug-loaded, bivalent-bottle-brush polymers by graft-through ROMP
Jeremiah A Johnson1, Ying Y Lu, Alan O Burts
1Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125.
Macromolecules
|May 3, 2011
Summary
Researchers created novel drug-delivering polymers using graft-through ring-opening metathesis polymerization. These stimuli-responsive polymers release anticancer drugs upon light exposure, significantly enhancing cancer cell toxicity.
Area of Science:
- Polymer Chemistry
- Materials Science
- Nanotechnology
Background:
- Ring-opening metathesis polymerization (ROMP) is a powerful technique for synthesizing complex polymer architectures.
- Bottle-brush polymers offer unique properties due to their highly branched structures.
- Stimuli-responsive polymers can release therapeutic agents in a controlled manner.
Purpose of the Study:
- To synthesize the first bivalent-brush polymers using graft-through ROMP.
- To incorporate anticancer drugs doxorubicin (DOX) and camptothecin (CT) into polymer structures.
- To investigate light-triggered drug release and its effect on cancer cell toxicity.
Main Methods:
- Graft-through ROMP utilizing ruthenium N-heterocyclic carbene catalysts.
- Synthesis of polyethylene-glycol (PEG) based macromonomers (MMs) functionalized with photocleavable linkers.
- Attachment of DOX and CT to norbornene-alkyne-PEG MMs.
- Preparation of polymer homo- and copolymers via ROMP.
- Photochemical drug release using 365 nm light.
Main Results:
- Successfully synthesized bivalent-brush polymers with low polydispersities and defined molecular weights.
- Achieved controlled release of DOX and CT upon light irradiation.
- Demonstrated a significant increase (at least 10-fold) in toxicity against human cancer cells after photoinitiated drug release.
- Showcased a 30-fold increased toxicity for a copolymer containing both drugs upon irradiation.
Conclusions:
- Graft-through ROMP provides a versatile platform for creating stimuli-responsive bivalent-brush polymers.
- Photoinitiated drug release from these polymers enhances their therapeutic efficacy.
- This methodology enables systematic structure-function relationship studies for advanced polymer applications in biology.
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