Tough fibrous mats prepared by electrospinning mixtures of methacrylated poly(trimethylene carbonate) and methacrylated gelatin

Electrospun scaffolds prepared from combinations of synthetic and natural macromers (macromolecular monomers) are interesting materials for tissue engineering applications. In this study, hybrid fibrous mats composed of 10/0, 8/2, 6/4, 3/7, 1/9 and 0/10 (wt/wt) three-armed methacrylated poly(trimethylene carbonate) (PTMC-tMA) and methacrylated gelatin (GelMA) were prepared by electrospinning and photo-crosslinking. The elastomeric PTMC fibers only maintained a stable structure when electrospun in combination with GelMA. The hybrid materials showed two glass transition temperatures, which indicated the occurrence of phase separation. By varying the ratios of PTMC-tMA/GelMA from 8/2^_1/9 (wt/wt), electrospun mats with a fiber diameter ranging from 1037 to 419 nm, water uptake from 106 to 315%, porosity from 88.3 to 94.3%, tensile modulus from 0.643 to 0.216 MPa, elongation at break from 445 to 96%, maximum strength from 4.127 to 0.381 MPa and toughness from 1023 to 15 N/mm² were prepared. Culturing of human smooth muscle cells on hybrid fibrous mats made from 6/4, 3/7 and 1/9 PTMC-tMA/GelMA showed similar cell attachment and proliferation as compared to 100% GelMA fibrous mats. The toughness of the latter hybrid fibrous mats (539, 33 and 15 N/mm², respectively) was significantly higher than that of the 100% GelMA fibrous mats (3 N/mm²). In conclusion, tough hybrid fibrous mats with good cell adhesive properties were prepared by electrospinning and photo-crosslinking of mixtures of PTMC-tMA and GelMA.