3D biofabrication of thermoplastic polyurethane (TPU)/poly-L-lactic acid (PLLA) electrospun nanofibers containing maghemite (γ-Fe2O3) for tissue engineering aortic heart valve

Valvular dysfunction as the prominent reason of heart failure may causes morbidity and mortality around the world. The inability of human body to regenerate the defected heart valves necessitates the development of the artificial prosthesis to be replaced. Besides, the lack of capacity to grow, repair or remodel of an artificial valves and biological difficulty such as infection or inflammation make the development of tissue engineering heart valve (TEHV) concept. This research presented the use of compound of poly-L-lactic acid (PLLA), thermoplastic polyurethane (TPU) and maghemite nanoparticle ( -Fe2O3) as the potential biomaterials to develop three-dimensional (3D) aortic heart valve scaffold. Electrospinning was used for fabricating the 3D scaffold. The steepest ascent followed by the response surface methodology was used to optimize the electrospinning parameters involved in terms of elastic modulus. The structural and porosity properties of fabricated scaffold were characterized using FE-SEM and liquid displacement technique, respectively. The 3D scaffold was then seeded with aortic smooth muscle cells (AOSMCs) and biological behavior in terms of cell attachment and proliferation during 34 days of incubation was characterized using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and confocal laser microscopy. Furthermore, the mechanical properties in terms of elastic modulus and stiffness were investigated after cell seeding through macro-indentation test. The analysis indicated the formation of ultrafine quality of nanofibers with diameter distribution of 178 ± 45 nm and 90.72% porosity. In terms of cell proliferation, the results exhibited desirable proliferation (109.32 ± 3.22% compared to the control) of cells over the 3D scaffold in 34 days of incubation. The elastic modulus and stiffness index after cell seeding were founded to be 22.78 ± 2.12 MPa and 1490.9 ± 12 Nmm2, respectively. Overall, the fabricated 3D scaffold exhibits desirable structural, biological and mechanical properties and has the potential to be used in vivo

Optimization and development of Maghemite (γ-Fe2O3) filled poly-L-lactic acid (PLLA)/thermoplastic polyurethane (TPU) electrospun nanofibers using Taguchi orthogonal array for tissue engineering heart valve

Tissue engineering (TE) is an advanced principle to develop a neotissue that can resemble the original tissue characteristics with the capacity to grow, to repair and to remodel in vivo. This research proposed the optimization and development of nanofiber based scaffold using the new mixture of maghemite (γ-Fe2O3) filled poly-L-lactic acid (PLLA)/thermoplastic polyurethane (TPU) for tissue engineering heart valve (TEHV). The chemical, structural, biological and mechanical properties of nanofiber based scaffold were characterized in terms of morphology, porosity, biocompatibility and mechanical behaviour. Two-level Taguchi experimental design (L8) was performed to optimize the electrospun mats in terms of elastic modulus using uniaxial tensile test where the studied parameters were flow rate, voltage, percentage of maghemite nanoparticles in the content, solution concentration and collector rotating speed. Each run was extended with an outer array to consider the noise factors. The signal-to-noise ratio analysis indicated the contribution percent as follow; Solution concentration > voltage > maghemite % > rotating speed > flow rate. The optimum elastic modulus founded to be 28.13 ± 0.37 MPa in such a way that the tensile strain was 31.72% which provided desirability for TEHV. An empirical model was extracted and verified using confirmation test. Furthermore, an ultrafine quality of electrospun nanofibers with 80.32% porosity was fabricated. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and cell attachment using human aortic smooth muscle cells exhibited desirable migration and proliferation over the electrospun mats. The interaction between blood content and the electrospun mats indicated a mutual adaption in terms of clotting time and hemolysis percent. Overall, the fabricated scaffold has the potential to provide the required properties of aortic heart valve

Developments in tissue engineering scaffolding using an electrospinning process

© 2017 Nova Science Publishers, Inc. Electrospinning is a simple and efficient process in producing nanofibers. The use of an electrospinning process in fabricating tissue engineering scaffolds has received great attention in recent years due to its simplicity and ability to fabricate ultrafine nanofibers. Most of the recent progress in tissue engineering has embarked on the use of nanofibers as tissue engineering scaffolds. This is because nanofibers can replicate the structural design of natural human tissue at the nano-scale thus shortening the healing time. Although electrospinning is a simple process, there are still several parameters which need to be controlled or optimised in order to produce nanofibers with different characteristics. Different applications might require nanofibers with specific criteria to be produced. Hence, this review will reveal the fundamental working principles of electrospinning process and the effect of electrospinning process parameters towards the nanofibers morphology. Various polymeric materials and their composites/blends have been successfully electrospun for tissue engineering (TE) scaffolds and they have been tabulated. In many cases, secondary processes are also integrated with the electrospinning process so as to develop 3D TE scaffolds and overcome limitations in term of the nanofiber thickness

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

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 (γ-Fe2O3) 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