Strong and tough mineralized PLGA nanofibers for tendon-to-bone scaffolds.
Engineering complex tissues such as the tendon-to-bone insertion sites require a strong and tough biomimetic material system that incorporates both mineralized and unmineralized tissues with different strengths and stiffnesses. However, increasing strength without degrading toughness is a fundamental challenge in materials science. Here, we demonstrate a promising nanofibrous polymer-hydroxyapatite system, in which, a continuous fibrous network must function as a scaffold for both mineralized and unmineralized tissues. It is shown that the high toughness of this material system could be maintained without compromising on the strength with the addition of hydroxyapatite mineral. Individual electrospun poly (lactide-co-glycolide) (PLGA) nanofibers demonstrated outstanding strain-hardening behavior and ductility when stretched uniaxially, even in the presence of surface mineralization. This highly desirable hardening behavior which results in simultaneous nanofiber strengthening and toughening was shown to depend on the initial cross-sectional morphology of the PLGA nanofibers. For pristine PLGA nanofibers, it was shown that ellipsoidal cross-sections provide the largest increase in fiber strength by almost 200% compared to bulk PLGA. This exceptional strength accompanied by 100% elongation was shown to be retained for thin and strongly bonded conformal mineral coatings, which were preserved on the nanofiber surface even for such very large extensions.
Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Pavan V
PV
Kolluru
Justin
J
Lipner
Wenying
W
Liu
Younan
Y
Xia
Stavros
S
Thomopoulos
Guy M
GM
Genin
Ioannis
I
Chasiotis
D001842:Bone and Bones / Q000502:physiology*; D055119:Elastic Modulus; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D008903:Minerals / Q000737:chemistry*; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D013710:Tendons / Q000502:physiology*; D013718:Tensile Strength; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
D008903:Minerals; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid
Bone; Electrospinning, mechanical properties; Tendon-to-bone insertion; Tissue engineering