The effects of PVP(FE(III)) catalyst and polymer molecular weight on gene delivery via biodegradable crosslinked polyethylenimine

Shum, Wing T.

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https://hdl.handle.net/2142/18635 Copy

Description

Title

The effects of PVP(FE(III)) catalyst and polymer molecular weight on gene delivery via biodegradable crosslinked polyethylenimine

Author(s)

Shum, Wing T.

Issue Date

2011-01-21T22:52:37Z

Director of Research (if dissertation) or Advisor (if thesis)

Pack, Daniel W.

Department of Study

Chemical & Biomolecular Engr

Discipline

Chemical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Non-viral gene delivery
• polyethylenimine
• polyethylenimines (PEI)
• biodegradable
• cross-link
• diacrylate
• transfection
• polyplex
• cellular uptake

Abstract

Human gene therapy has faced many setbacks due to the immunogenicity and oncogenity of viruses. Safe and efficient alternative gene delivery vehicles are needed to implement gene therapy in clinical practice. Polymeric vectors are an attractive option due to their availability, simple chemistry, and low toxicity and immunogenicity. Our group has previously reported biodegradable polyethylenimines (PEI) that show high transfection efficiency and low toxicity by cross-linking 800 Da PEI with diacrylate cross-linkers using Michael addition. However, the synthesis was difficult to control, inconsistent, and resulted in polymers with a narrow range of molecular weights. In the present work, we utilized a heterogenous PVP(Fe(III)) catalyst to provide a more controllable PEI crosslinking reaction and wider range of biodegradable PEIs. The biodegradable PEIs reported here have molecular weights ranging from 1.2 kDa to 48 kDa, are nontoxic in MDA-MB-231 cells, and show low toxicity in HeLa cells. At their respective optimal polymer:DNA ratios, these biodegradable PEIs demonstrated about 2-5-fold higher transfection efficiency and 2-7-fold higher cellular uptake, compared unmodified 25 kDa PEI. The biodegradable PEIs show similar DNA condensation properties as unmodified PEI but more readily unpackage DNA, based on ethidium bromide exclusion and heparan sulfate competitive displacement assays, which could contribute to their improved transfection efficiency. Overall, the synthesis reported here provides a more robust, controlled reaction to produce cross-linked biodegradable PEIs that show enhanced gene delivery, low toxicity, and high cellular uptake and can potentially be used for future in vivo studies.

Graduation Semester

2010-12

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http://hdl.handle.net/2142/18635

Copyright and License Information

Copyright 2010 Wing Tat Victor Shum

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