A modular, injectable, non-covalently assembled hydrogel system features widescale tunable degradability for...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Biomaterials are crucial for tissue engineering, requiring biocompatibility and mimicry of native extracellular matrices (ECM).
• Tailorable properties like degradability, injectability, and controlled release of bioactive molecules are essential for advanced biomedical applications.
• Developing materials that minimize adverse host reactions while promoting tissue integration and regeneration remains a key challenge.

Purpose of the Study:

• To develop and characterize a novel, injectable hydrogel system based on non-covalent interactions between oligopeptides and sulphated polysaccharides.
• To evaluate the biocompatibility, in vivo degradation, and bioactive molecule release capabilities of the developed hydrogel system.
• To investigate the potential of these ECM-mimetic hydrogels as tunable scaffolds for tissue engineering and controlled delivery of signaling molecules.

Main Methods:

• Fabrication of injectable hydrogels via self-assembly of oligopeptides and sulphated polysaccharides.
• In vivo assessment of hydrogel tolerability, biocompatibility, and degradation kinetics in immunocompetent hairless mice.
• In vivo and in vitro evaluation of degradation-mediated release of heparin-binding molecules and growth factor expression (e.g., vascular endothelial growth factor).
• Utilized small animal magnetic resonance imaging and fluorescence imaging for tracking molecule release and assessing biological effects.

Main Results:

• The peptide-polysaccharide hydrogels demonstrated high tolerability and biocompatibility in vivo.
• In vivo degradation rates were tunable, ranging from a half-life of three weeks to undetectable degradation over three months by altering components.
• Sustained, degradation-mediated release of heparin-binding molecules was observed in vivo, accompanied by enhanced vascular endothelial growth factor expression.
• In vitro studies suggested M2-macrophages play a role in the observed pro-angiogenic effects.

Conclusions:

• The developed ECM-mimetic, injectable hydrogels are highly biocompatible and offer tunable degradation profiles.
• These hydrogels facilitate controlled release of heparin-binding signaling molecules, including growth factors, in a degradation-dependent manner.
• The tunable bioactive scaffolds show significant promise for tissue engineering applications, promoting regeneration and vascularization.