Artem Boris Kutikov successfully defended his PhD Thesis on Monday, November 24, 2014. Artem's thesis was titled "Amphiphilic Degradable Polymer/Hydroxyapatite Composites As Smart Bone Tissue Engineering Scaffolds." Dr. Kutikov's Mentor is Jie Song, PhD from the Orthopedics Department. The Dissertation Exam Committee was Chaired by Paul Odgren, PhD and included David Ayers, MD, Gang Han, PhD, Jaime Rivera, PhD and George D. Pins, PhD.
Over 600,000 bone-grafting operations are performed each year in the United States. The majority of the bone used for these surgeries comes from autografts that are limited in quantity or allografts with high failure rates. Current synthetic bone grafting materials have poor mechanical properties, handling characteristics, and bioactivity. My thesis work describes the development of a smart bone tissue engineering scaffold based on a composite of the biodegradable amphiphilic polymer poly(D,L-lactic acid-co-ethylene glycol-co-D,L-lactic acid) (PELA) and hydroxyapatite (HA), the principle mineral component in bone. I showed that electrospun nanofibrous HA-PELA scaffolds are hydrophilic, elastic, stiffen upon hydration, and support the attachment and osteogenic differentiation of rat bone marrow stromal cells (MSCs). These in vitro properties translated into robust bone formation in vivo using a critical-size femoral defect model in rats. Spiral-wrapped HA-PELA scaffolds, loaded with MSCs or a low-dose of recombinant human bone morphogenetic protein-2, template bone formation along the defect. As an alternate approach, I showed that PELA and HA-PELA can be rapid prototyped into three-dimensional (3-D) macroporous scaffolds. These 3-D scaffolds have differential cell adhesion characteristics, swell and stiffen upon hydration, and exhibit self-fixation in a simulated confined defect. HA-PELA also exhibits thermal shape memory behavior, enabling the minimally invasive delivery and rapid (>3 sec) shape recovery of 3-D scaffolds at physiologically safe temperatures (~ 50ºC). Overall, I demonstrate how the rational selection of FDA-approved materials with synergistic interactions results in smart biomaterials with high potential for clinical translation.
|Mentor Jie Song, PhD with Artem Kutikov, PhD|
|Artem Kutikov presents his thesis defense|