Engineering multiscale, biomimetic scaffolds based on protein-based materials as advanced cardiovascular implants

RWTH Publications (RWTH Aachen)

Abstract

The development of functional cardiovascular implants requires scaffolds that replicate native tissue mechanics, cellular cues, and structural organization, a challenge due to the trade-off between bioactivity and mechanical robustness in available materials. Bioactive materials often lack physiological strength, while mechanically stable materials may not support complex tissue regeneration or reproduce the hierarchical architecture essential for biomimicry. This thesis addresses these challenges in two parts: first, reinforcing biologically active matrices to meet mechanical demands, and second, achieving both material functionality and architectural fidelity. Fibrin, valued for its bioactivity and autologous sourcing, is limited in cardiovascular applications by poor mechanical properties and rapid degradation. We developed a composite scaffold combining fibrin with silk fibroin using a dual-injection process and ethanol annealing. Rheological analysis showed that adding 1% (w/v) silk fibroin increased the shear elastic modulus nearly 20-fold. These composites resisted contraction by human arterial smooth muscle cells and supported endothelialisation, demonstrating both mechanical resilience and biological compatibility. The second part focuses on replicating the hierarchical structure and elasticity of native tissues. We developed elastin-like hydrogel fibres using catalyst-free click chemistry and microscale injection moulding. These fibres exhibited high extensibility (up to 500% strain) with complete elastic recovery. A salt-leaching/gas-foaming step imparted tuneable porosity, and the fibres supported endothelial cell adhesion and alignment under physiological strain. Importantly, these fibres could be assembled using textile techniques to engineer scalable scaffolds with precise architectural control. Together, these complementary platforms bridge biological functionality, mechanical resilience, and architectural fidelity, advancing next-generation cardiovascular implants capable of dynamic integration and long-term performance.

Authors 1

1. Ikram El Maachi corresponding Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen