title: Small diameter electrospun silk fibroin vascular grafts: Mechanical properties, in vitro biodegradability, and in vivo biocompatibility.
abstract: To overcome the drawbacks of autologous grafts currently used in clinical practice, vascular tissue engineering represents an alternative approach for the replacement of small diameter blood vessels. In the present work, the production and characterization of small diameter tubular matrices (inner diameter (ID)=4.5 and 1.5 mm), obtained by electrospinning (ES) of Bombyx mori silk fibroin (SF), have been considered. ES-SF tubular scaffolds with ID=1.5 mm are original, and can be used as vascular grafts in pediatrics or in hand microsurgery. Axial and circumferential tensile tests on ES-SF tubes showed appropriate properties for the specific application. The burst pressure and the compliance of ES-SF tubes were estimated using the Laplace's law. Specifically, the estimated burst pressure was higher than the physiological pressures and the estimated compliance was similar or higher than that of native rat aorta and Goretex® prosthesis. Enzymatic in vitro degradation tests demonstrated a decrease of order and crystallinity of the SF outer surface as a consequence of the enzyme activity. The in vitro cytocompatibility of the ES-SF tubes was confirmed by the adhesion and growth of primary porcine smooth muscle cells. The in vivo subcutaneous implant into the rat dorsal tissue indicated that ES-SF matrices caused a mild host reaction. Thus, the results of this investigation, in which comprehensive morphological and mechanical aspects, in vitro degradation and in vitro and in vivo biocompatibility were considered, indicate the potential suitability of these ES-SF tubular matrices as scaffolds for the regeneration of small diameter blood vessels.
authors.affiliation: Biomaterials Laboratory, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. Da Vinci 32, Milano, Italy; Local Unit Politecnico di Milano, INSTM, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Catto
authors.affiliation: Biomaterials Laboratory, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. Da Vinci 32, Milano, Italy; Local Unit Politecnico di Milano, INSTM, Italy. Electronic address: silvia.fare@polimi.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Farè
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Bioengineering Department, via Stezzano 87, Bergamo, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Cattaneo
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Bioengineering Department, via Stezzano 87, Bergamo, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Figliuzzi
authors.affiliation: INNOVHUB - SSI, Div. Stazione Sperimentale per la Seta, via G. Colombo 83, Milan, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Alessandrino
authors.affiliation: INNOVHUB - SSI, Div. Stazione Sperimentale per la Seta, via G. Colombo 83, Milan, Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Freddi
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Bioengineering Department, via Stezzano 87, Bergamo, Italy; Università di Bergamo, Industrial Engineering Department, Via Marconi 5, Dalmine, Bergamo, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Remuzzi
authors.affiliation: Biomaterials Laboratory, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. Da Vinci 32, Milano, Italy; Local Unit Politecnico di Milano, INSTM, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Tanzi
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001807:Blood Vessel Prosthesis; D012831:Bombyx; D002448:Cell Adhesion; D005109:Extracellular Matrix / Q000737:chemistry; D005349:Fibroins / Q000737:chemistry*; D008297:Male; D008954:Models, Biological; D032389:Myocytes, Smooth Muscle; D049329:Nanostructures / Q000737:chemistry; D051381:Rats; D011917:Rats, Inbred Lew; D017207:Rats, Sprague-Dawley; D013552:Swine; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D005349:Fibroins
keywords: Electrospinning; In vitro and in vivo biocompatibility; In vitro degradation; Mechanical properties; Silk fibroin; Small diameter vascular grafts