Tuning the Properties of Elastin Mimetic Hybrid Copolymers via a Modular Polymerization Method

Department of Materials Science and Engineering, Delaware Biotechnology Institute, University of Delaware, Newark, Delaware 19716, United States.
Biomacromolecules (Impact Factor: 5.79). 04/2012; 13(6):1774-86. DOI: 10.1021/bm3002705
Source: PubMed

ABSTRACT We have synthesized elastin mimetic hybrid polymers (EMHPs) via the step-growth polymerization of azide-functionalized poly(ethylene glycol) (PEG) and alkyne-terminated peptide (AKAAAKA)(2) (AK2) that is abundant in the cross-linking domains of the natural elastin. The modular nature of our synthesis allows facile adjustment of the peptide sequence to modulate the structural and biological properties of EMHPs. Therefore, EMHPs containing cell-binding domains (CBDs) were constructed from α,ω-azido-PEG and two types of alkyne-terminated AK2 peptides with sequences of DGRGX(AKAAAKA)(2)X (AK2-CBD1) and X(AKAAAKA)(2)XGGRGDSPG (AK2-CBD2, X = propargylglycine) via a step-growth, click coupling reaction. The resultant hybrid copolymers contain an estimated five to seven repeats of PEG and AK2 peptides. The secondary structure of EMHPs is sensitive to the specific sequence of the peptidic building blocks, with CBD-containing EMHPs exhibiting a significant enhancement in the α-helical content as compared with the peptide alone. Elastomeric hydrogels formed by covalent cross-linking of the EMHPs had a compressive modulus of 1.06 ± 0.1 MPa. Neonatal human dermal fibroblasts (NHDFs) were able to adhere to the hydrogels within 1 h and to spread and develop F-actin filaments 24 h postseeding. NHDF proliferation was only observed on hydrogels containing RGDSP domains, demonstrating the importance of integrin engagement for cell growth and the potential use of these EMHPs as tissue engineering scaffolds. These cell-instructive, hybrid polymers are promising candidates as elastomeric scaffolds for tissue engineering.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Hybrid block copolymers based on peptides and synthetic polymers, displaying different types of topologies, offer new possibilities to integrate the properties and functions of biomacromolecules and synthetic polymers in a single hybrid material. This review provides a current status report of the field concerning peptide-synthetic polymer hybrids. The first section is focused on the different synthetic approaches that have been used within the last three years for the preparation of peptide-polymer hybrids having different topologies. In the last two sections, the attractive properties, displayed in solution or in the solid state, together with the potential applications of this type of macromolecules or supramolecular systems are highlighted.
    Polymers 03/2013; 5(1):188-224. DOI:10.3390/polym5010188 · 2.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Wound healing results from complex signaling between cells and their environment in response to injury. Fibroblasts residing within the extracellular matrix (ECM) of various connective tissues are critical for matrix synthesis and repair. Upon injury or chronic insult, these cells activate into wound-healing cells, called myofibroblasts, and repair the damaged tissue through enzyme and protein secretion. However, misregulation and persistence of myofibroblasts can lead to uncontrolled accumulation of matrix proteins, tissue stiffening, and ultimately disease. Extracellular cues are important regulators of fibroblast activation and have been implicated in their persistence. Hydrogel-based culture models have emerged as useful tools to examine fibroblast response to ECM cues presented during these complex processes. In this Mini-Review, we will provide an overview of these model systems, which are built upon naturally-derived or synthetic materials, and mimic relevant biophysical and biochemical properties of the native ECM with different levels of control. Additionally, we will discuss the application of these hydrogel-based systems for the examination of fibroblast function and fate, including adhesion, migration, and activation, as well as approaches for mimicking both static and temporal aspects of extracellular environments. Specifically, we will highlight hydrogels that have been used to investigate the effects of matrix rigidity, protein binding, and cytokine signaling on fibroblast activation. Last, we will describe future directions for the design of hydrogels to develop improved synthetic models that mimic the complex extracellular environment.
    05/2014; 2(5):634-650. DOI:10.1039/C3BM60319A
  • [Show abstract] [Hide abstract]
    ABSTRACT: Temperature-triggered formation of nanostructures with distinct biological activity offers opportunities in selective modification of matrices and in drug delivery. Toward these ends, diblock polymers comprising poly(diethylene glycol methyl ether methacrylate) (PDEGMEMA) conjugated to a triple helix-forming collagen-like peptide were produced. Triggered by the collapse of the thermoresponsive domain above its LCST, the conjugate undergoes a reversible transition in aqueous solution to form well-defined nanovesicles with diameters of approximately 100 nm, with a transition temperature of 37 °C. The incorporation of CLP domains in these nanostructures may offer opportunities for the selective targeting of collagen-containing matrices.
    Macromolecular Bioscience 11/2014; 15(1). DOI:10.1002/mabi.201400358 · 3.65 Impact Factor

Full-text (2 Sources)

Available from
May 19, 2014