Acute and chronic wounds cause pain and suffering, in addition to significant morbidity and risk of infection, to a large number of people each year. As a result, there is considerable need for new therapeutics that induces and accelerate wound repair. Basic fibroblast growth factor (bFGF) stimulates the proliferation and migration of several cell types that have crucial roles in wound healing. However, the protein is rapidly degraded when delivered or upon storage, thus far preventing its therapeutic use. One objective of this research is to stabilize bFGF by covalently conjugating a synthetic polymer that mimics a natural protector of the protein, heparin. bFGF induces dimerization of its receptors and heparin aids in receptor activation. Thus, a second objective on this research is to produce dimeric polymer conjugates of bFGF in order to increase the mitogenic and migratory cellular activity of the protein relative to unmodified bFGF. The third objective is to test preclinical efficacy of the bFGF conjugates to heal wounds.
Three specific aims are proposed to reach these objectives.
The first aim i s to evaluate the stability of bFGF-p (SS)-co-PEGMA polymer conjugates compared to controls and cytotoxicity of the polymers. It is hypothesized that bFGF- p (SS)-co-PEGMA will be more stable than bFGF-pPEGMA, bFGF-PEG and the unmodified protein, and the polymers will be nontoxic at therapeutically useful concentrations. To accomplish this, stability of the bFGF conjugate against trypsin, acidic pH, heat, stirring, and storage will be quantified by standard biochemical and cellular assays.
The second aim i s to determine in vitro bioactivity of bFGF-p (SS)-co-PEGMA-bFGF conjugates. It is hypothesized that dimeric bFGF p (SS)-co-PEGMA conjugates will be more active in human dermal fibroblast (HDF) and human dermal keratinocyte (HDK) cell proliferation and migration assays than the monomeric conjugates and bFGF alone. To investigate this, conjugate-induced stimulation of cell proliferation and migration of cells in vitro will be ascertained. Receptor activation will be verified.
The third aim i s to determine the ability of dimeric and monomeric bFGF sulfonated polymer conjugates to enhance wound healing. It is hypothesized that dimeric bFGF p(SS)-co-PEGMA conjugates will be more effective at healing normal and diabetic wounds in vitro and in vivo than the monomeric conjugate or bFGF alone. To test this, organotypic cultures and superficial wounding models in mice will be employed. One potential outcome of this research is to develop an active agent that promotes skin repair. The long-term goal of this research is to produce efficacious and stable therapeutics to treat acute and chronic wounds.

Public Health Relevance

Establishing preclinical efficacy of a novel wound healing agent is proposed. If successful, the protein-polymer conjugate will induce and accelerate wound healing and repair. Treatment of acute and chronic wounds is of major importance to human health.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB013674-02
Application #
8398914
Study Section
Biomaterials and Biointerfaces Study Section (BMBI)
Program Officer
Hunziker, Rosemarie
Project Start
2011-12-15
Project End
2015-11-30
Budget Start
2012-12-01
Budget End
2013-11-30
Support Year
2
Fiscal Year
2013
Total Cost
$321,148
Indirect Cost
$108,973
Name
University of California Los Angeles
Department
Type
Organized Research Units
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Paluck, Samantha J; Maynard, Heather D (2017) Structure Activity Relationship of Heparin Mimicking Polymer p(SS-co-PEGMA): Effect of Sulfonation and Polymer Size on FGF2-Receptor Binding. Polym Chem 8:4548-4556
Shen, Lu; Decker, Caitlin G; Maynard, Heather D et al. (2016) Calculating the mean time to capture for tethered ligands and its effect on the chemical equilibrium of bound ligand pairs. Data Brief 8:506-15
Vanparijs, Nane; Nuhn, Lutz; Paluck, Samantha J et al. (2016) Core/shell protein-reactive nanogels via a combination of RAFT polymerization and vinyl sulfone postmodification. Nanomedicine (Lond) 11:2631-2645
Decker, Caitlin G; Wang, Yu; Paluck, Samantha J et al. (2016) Fibroblast growth factor 2 dimer with superagonist in vitro activity improves granulation tissue formation during wound healing. Biomaterials 81:157-168
Paluck, Samantha J; Nguyen, Thi H; Lee, Jonghan P et al. (2016) A Heparin-Mimicking Block Copolymer Both Stabilizes and Increases the Activity of Fibroblast Growth Factor 2 (FGF2). Biomacromolecules 17:3386-3395
Paluck, Samantha J; Nguyen, Thi H; Maynard, Heather D (2016) Heparin-Mimicking Polymers: Synthesis and Biological Applications. Biomacromolecules 17:3417-3440
Nguyen, Thi H; Paluck, Samantha J; McGahran, Andrew J et al. (2015) Poly(vinyl sulfonate) Facilitates bFGF-Induced Cell Proliferation. Biomacromolecules 16:2684-92
Decker, Caitlin G; Maynard, Heather D (2015) Degradable PEGylated Protein Conjugates Utilizing RAFT Polymerization. Eur Polym J 65:305-312
Boehnke, Natalie; Cam, Cynthia; Bat, Erhan et al. (2015) Imine Hydrogels with Tunable Degradability for Tissue Engineering. Biomacromolecules 16:2101-8
Griffin, Donald R; Schlosser, Jessica L; Lam, Sandra F et al. (2013) Synthesis of photodegradable macromers for conjugation and release of bioactive molecules. Biomacromolecules 14:1199-207

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