Extracellular matrix-derived and low-cost proteins to improve polyurethane-based scaffolds for vascular grafts.

Vascular graft surgeries are often conducted in trauma cases, which has increased the demand for scaffolds with good biocompatibility profiles. Biodegradable scaffolds resembling the extracellular matrix (ECM) of blood vessels are promising vascular graft materials. In the present study, polyurethane (PU) was blended with ECM proteins collagen and elastin (Col-El) and gelatin (Gel) to produce fibrous scaffolds by using the rotary jet spinning (RJS) technique, and their effects on in vitro properties were evaluated. Morphological and structural characterization of the scaffolds was performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Micrometric fibers with nanometric rugosity were obtained. Col-El and Gel reduced the mechanical strength and increased the hydrophilicity and degradation rates of PU. No platelet adhesion or activation was observed. The addition of proteins to the PU blend increased the viability, adhesion, and proliferation of human umbilical vein endothelial cells (HUVECs). Therefore, PU-Col-El and PU-Gel scaffolds are promising biomaterials for vascular graft applications.

A novel technique to produce tubular scaffolds based on collagen and elastin.

Tubular polymer scaffolds based on tissue engineering techniques have been studied as potential alternatives for vascular regeneration implants. The blood vessels of the cardiovascular system are mainly fibrous, composed of collagen (Col) and elastin (El), and its inner layer consists of endothelial cells. In this work, Col and El were combined with polyurethane (PU), a biocompatible synthetic polymer, and rotary jet spinning, a new and highly productive technique, to produce fibrous scaffolds. The scaffolds produced at 18 000 rpm presented homogeneous, bead-free, and solvent-free fibers. The blend formation between PU-Col-El was identified by chemical composition analysis and enhanced the thermal stability up to 324°C. The hydrophilic nature of the scaffold was revealed by its low contact angle. Cell viability of human umbilical vein endothelial cells with the scaffold was proven for 72 hours. The combined strategy of rotary jet spinning with a polymer blend containing Col and El was verified as an effective and promising alternative to obtain tubular scaffolds for tissue engineering on a large-scale production.