**Small Diameter Cell-Free Tissue-Engineered Vascular Grafts: Biomaterials and Manufacture Techniques to Reach Suitable Mechanical Properties**

**María A. Rodríguez-Soto 1,\* , Camilo A. Polanía-Sandoval 2,3, Andrés M. Aragón-Rivera <sup>1</sup> , Daniel Buitrago <sup>1</sup> , María Ayala-Velásquez <sup>1</sup> , Alejandro Velandia-Sánchez 2,3 , Gabriela Peralta Peluffo <sup>1</sup> , Juan C. Cruz <sup>1</sup> , Carolina Muñoz Camargo <sup>1</sup> , Jaime Camacho-Mackenzie <sup>2</sup> , Juan Guillermo Barrera-Carvajal <sup>2</sup> and Juan Carlos Briceño 1,4,\***

	- <sup>3</sup> School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 111711, Colombia
	- <sup>4</sup> Department of Research, Fundación Cardio Infantil Instituto de Cardiología, Bogotá 111711, Colombia
	- **\*** Correspondence: ma.rodriguezs1@uniandes.edu.co (M.A.R.-S.); jbriceno@uniandes.edu.co (J.C.B.); Tel.: +57-(1)-3394949 (ext. 1789) (M.A.R.-S.)

**Citation:** Rodríguez-Soto, M.A.; Polanía-Sandoval, C.A.; Aragón-Rivera, A.M.; Buitrago, D.; Ayala-Velásquez, M.; Velandia-Sánchez, A.; Peralta Peluffo, G.; Cruz, J.C.; Muñoz Camargo, C.; Camacho-Mackenzie, J.; et al. Small Diameter Cell-Free Tissue-Engineered Vascular Grafts: Biomaterials and Manufacture Techniques to Reach Suitable Mechanical Properties. *Polymers* **2022**, *14*, 3440. https:// doi.org/10.3390/polym14173440

Academic Editors: Domenico Acierno and Antonella Patti

Received: 1 June 2022 Accepted: 6 July 2022 Published: 23 August 2022

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**Abstract:** Vascular grafts (VGs) are medical devices intended to replace the function of a blood vessel. Available VGs in the market present low patency rates for small diameter applications setting the VG failure. This event arises from the inadequate response of the cells interacting with the biomaterial in the context of operative conditions generating chronic inflammation and a lack of regenerative signals where stenosis or aneurysms can occur. Tissue Engineered Vascular grafts (TEVGs) aim to induce the regeneration of the native vessel to overcome these limitations. Besides the biochemical stimuli, the biomaterial and the particular micro and macrostructure of the graft will determine the specific behavior under pulsatile pressure. The TEVG must support blood flow withstanding the exerted pressure, allowing the proper compliance required for the biomechanical stimulation needed for regeneration. Although the international standards outline the specific requirements to evaluate vascular grafts, the challenge remains in choosing the proper biomaterial and manufacturing TEVGs with good quality features to perform satisfactorily. In this review, we aim to recognize the best strategies to reach suitable mechanical properties in cell-free TEVGs according to the reported success of different approaches in clinical trials and pre-clinical trials.

**Keywords:** tissue engineered vascular grafts; biomaterials; biodegradable; biomechanical stimulation; mechanical properties
