Piezoelectric Poly(3-hydroxybutyrate)-Poly(lactic acid) Three Dimensional Scaffolds for Bone Tissue Engineering

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1025-B12-03

Piezoelectric Poly(3-hydroxybutyrate)-Poly(lactic acid) Three Dimensional Scaffolds for Bone Tissue Engineering Juana Mendenhall1, Dapeng Li2,3, Margaret Frey2, Juan Hinestroza2, Omotunde Babalola4, Lawrence Bonnasar4, and Carl A Batt1 1 Food Science, Cornell University, Ithaca, NY, 14853 2 Fiber Science and Apparel Design, Cornell University, Ithaca, NY, 14853 3 Material Science and Textile Department, U Mass Dartmouth, North Dartmouth, NY, 02747 4 Biomedical Engineering, Cornell University, Ithaca, NY, 14853 ABSTRACT Three dimensional scaffolds (3D) are promising for future nanoscale materials and tissue engineering applications being that they have architecture and mechanical properties similar to natural tissue. In this work, poly(lactic acid) fibers were prepared via electrospinnig with average diameters of 2580 nm. Using Enzymatic Surface-Initiated polymerization (ESIP), poly(3hydroxybutyrate) were coated on poly(lactic acid) fibers. This provides an alternative method to enzymatic surface modification of fibers. ESIP of PHB produces a granular film providing surface topography and increases mechanical properties of PLA fibers alone. When using covalent approaches, PHB granules provide surface topography of 200-500 nm with a polydisperse coverage area. Compressive modulus measurements of PLA and PHB/PLA scaffolds were 25 kPa and 73 kPa, respectively. The percent crystallinity of PLA and PHB/PLA scaffolds was 17% and 30%, respectively. This rough topography, in addition to the crystallinity of the scaffold, facilitates Soas-2 osteoblast cell attachment. We have observed attachment of the osteoblast cells along the length of the oriented PLA and PHB/PLA composite scaffolds with different morphologies, rounded and stretched, throughout a depth of 90 µm. INTRODUCTION In tissue engineering, three dimensional scaffolds hold a promise as a mimic of native tissue with the ability to tailor these specific scaffolds to desired properties. Electrospinning of polymeric materials creates three dimensional nano and micro- fibers, which are attractive biomaterial scaffolds for tissue engineering applications [1]. The scaffold materials, surface topography, mechanical properties, in addition to surface chemistry, all affect cell response and ultimately tissue development. Polyhydroxyalkanoates (PHA) are a family of bacteria produced polymers that have shown potential in the area of tissue engineering applications [2]. One member of the PHA family, poly(3-hydroxybutyrate)(PHB) and its copolymers, has been reported to be useful in biomedical applications due to its biodegradability, biocompatibility, and thermoprocessability [3,4]. Many groups have reported using commercially available PHB and it’s copolymers for biomedical applications, e.g. bone tissue scaffolds and cartilage engineering [5]. Here, for the first time we report the in situ Enzymatic Surface-Initiated (ESIP) of PHB on electrospun PLA three dimensional scaffolds. Surface-initiated polymerization has been demonstrated on solid surfaces and offers ver