Characterization of maghemite (γ-Fe2O3)-loaded poly-l-lactic acid/thermoplastic polyurethane electrospun mats for soft tissue engineering

Abstract

This study proposed a new mixture of three different biocompatible and biodegradable materials for soft tissue which needs elasticity and stretchability as well as stiffness. Five different ratios of poly-L-lactic acid (PLLA)/thermoplastic polyurethane (TPU) blend containing 1 % (w/v) maghemite (c-Fe 2 O 3 ) nanoparticles were electrospun and characterized in terms of morphology, degradation rate, biological compatibility, and mechanical properties for tunable properties. Neat PLLA/TPU samples were used for maghemite effect verification. The existence of three components in the electrospun mats was confirmed by Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy. Scanning electron microscopy images illustrated well-fabricated nanofibers with smaller diameter distribution for PLLA. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using human skin fibroblast cell indicates desired proliferation and migrant over the samples. Blood biocompatibility results in terms of clotting time, fibrin formation, and hemolysis were almost in the normal range. Samples' degradation rate was investigated over 24 weeks where the PLLA shows 47.15 % mass change, while 6.7 % of TPU mass changed. High tensile strength and an extremely low elongation at break were determined from the stress-strain curve for PLLA, while TPU exhibits high elasticity. The 50:50 % ratio of 1 % (w/v) maghemite-loaded PLLA/TPU scaffold presents an overall satisfaction.

3D Biofabrication of Thermoplastic Polyurethane (TPU)/Poly-l-lactic Acid (PLLA) Electrospun Nanofibers Containing Maghemite (γ-Fe2O3) for Tissue Engineering Aortic Heart Valve

“…Furthermore, it is expected that, when the polymers fully degrade, the maghemite nanoparticles are dispersed in the blood circulation and removed by the spleen or kidney, depending on their size. However, the biocompatibility of maghemite has been verified previously [ 5 , 34 , 52 , 53 ].…”

“…The degradability of PLLA and TPU is already verified in terms of changes in the morphology, mass and porosity [ 5 , 35 ] where a 50:50% (TPU/PLLA) scaffold during 24 weeks of incubation in simulated body fluid (SBF), had lose 47.15% of its mass while the morphology showed breakage on the fibers and porosity was increased roughly 15%. The 15 mL of 50:50% TPU/PLLA ( v/v ) (with 6.54 wt % of concentration) solution was prepared by mixing PLLA and TPU solutions using a magnetic stirrer for 5 h, at room temperature (25 °C) to get a homogeneous solution.…”

“…Based on tissue engineering (TE) principle, a three-dimensional (3D) scaffold is fabricated using the biomaterials as the initial template for the cells. The shape, structure and mechanical properties of fabricated scaffold should resemble the original aortic heart valve [ 2 , 5 ]. Thus the utilized materials as well as fabrication technique can significantly influence the scaffold properties.…”

“…In our previous study [ 5 ], maghemite (γ-Fe 2 O 3 ) loaded thermoplastic polyurethane (TPU)/poly- l -lactic acid (PLLA) was used as a novel mixture for fabricating aortic heart valve’s engineered tissue. The presence of maghemite nanoparticles in the nanofibers latter’s surface improved both cell proliferation rate and also the mechanical properties [ 10 , 34 ].…”

Curcumin‐loaded biodegradable polyurethane scaffolds modified with gelatin using 3D printing technology for cartilage tissue engineering

“…Biodegradable polymers such as polylactic acid, polyglycolic acid, polylactic‐co‐glycolic acid, and poly(ε‐caprolactone) (PCL) can undergo hydrolysis and have all been used to fabricate tissue engineering scaffolds. However, these materials lack a proper elasticity matching that of living tissue . Polyurethane (PU) is one of the most widely used polymers in biomedical applications because of its good biocompatibility and mechanical properties.…”