3D tubular constructs based on natural polysaccharides and recombinant polypeptide synergistic blends as potential candidates for blood vessel solutions.

The development of versatile tubular structures is critical for tissue engineering (TE) applications where vascularization is necessary. This study investigates the fabrication of tubular shaped biomaterials focused on chitosan (CHT) combined with alginate (ALG) and acemannan (ACE), known for their synergistic properties, including physical stability, antibacterial activity, and healing promotion. Translating this CHT/ACE/ALG blend into 3D tubular architectures via the freeze-drying technology resulted in flexible tubes with dimensional stability, and well-defined hollow interiors. Testing these tubes for their water uptake capacity and stability indicated a substantial water absorption (about 20-fold of their dry mass), and they maintained structural integrity under physiological conditions over seven days. Structural analyses using SEM and Micro-CT revealed uniform morphology and porosity, crucial for nutrient and oxygen diffusion. Elastin-like recombinamers (ELRs) containing the QK peptide - a peptide sequence that mimics the vascular endothelial growth factor (VEGF) - were incorporated into the tubular structures, to enhance the bioactivity and the mechanical behavior of the constructs. This modification led to a reduction in porosity but without affecting endothelial cells viability, with pore size ≥100 μm was maintained. The sustained release of bioactive compounds, including ACE and ELRs, was shown to improve endothelial cells viability. Our approach thus opens new possibilities for the design of tubular structures with customizable length, diameter, stability, and bioactivity, particularly in cardiovascular applications.