CAREER: Printed Magnetoelectric Composites as a Bioscaffold for Bone Tissue Engineering

Non-technical abstract Osteoporosis, trauma, severe inflammation, and the removal of bone cancer tumors can lead to large bone defects that exceed the self-healing capacity of human bones. Bone graft surgery, which involves transplanting healthy bone tissues from the patient or a donor to the damaged area, is the gold standard for treating these defects. In the U.S., approximately 600,000 bone grafts are performed annually, making bone the second most transplanted tissue after blood. However, bone grafts come with risks, including infection at the donor site, restrictions on graft size, limited tissue availability, and the potential for immune rejection and pathogen transmission. An alternative approach, bone tissue engineering, can create transplantable bone substitutes by growing healthy tissues from the patient’s own mesenchymal stem cells (MSCs) on implantable biomaterials. However, MSCs can differentiate into various cell types beyond bone, including cartilage, muscle, tendon, and vascular cells. Thus, advanced biomaterials are needed to promote MSC growth while guiding their differentiation specifically into bone-forming cells. This NSF CAREER project aims to develop a novel magnetically responsive biomaterial that can replicate the microstructures and physical stimuli of natural human bones. To achieve this, the biomaterial will be printed into three-dimensional porous biological scaffolds, offering a large surface area for cell attachment and micro-channels for nutrient delivery. Additionally, this biomaterial will exhibit changes in stiffness, mechanically deform, and generate electricity in response to magnetic field excitations. These dynamic properties closely mimic the critical stimuli offered by natural bones. Leveraging these unique properties, this study will investigate the use of magnetic fields to control the growth and differentiation of MSCs. To foster the growth of Idaho's scientific workforce, an integrated education plan will provide professional development opportunities for local high school teachers, establish project-based science curricula for high school students, and create hands-on, service-learning courses for college students. Technical Abstract This CAREER project aims to revolutionize bone defect treatment by developing a transformative magnetoelectric biomaterial replicating the complex mechanobiological environments in human bones. This functional biomaterial, made of magnetostrictive terbium-iron-dysprosium nanoparticles dispersed in a piezoelectric polyvinylidene fluoride polymer matrix, can generate precise, nonintrusive mechanical cues through two unique mechanisms: the Delta-E effect, mimicking elasticity variations during bone growth, and the magnetoelectric effect, mimicking mechanical vibrations and piezoelectric stimuli found in bones. However, magnetoelectric biomaterials are still nascent in bone tissue engineering, as early studies have been limited to two-dimensional bioscaffolds with inconsistent material properties and unproven efficacy. By integrating additive manufacturing, multiphysics material characterization, and in vitro testing, three key research objectives will be pursued in this project: (1) Print three-dimensional magnetoelectric bioscaffolds that mimic the porous morphology and mechanical strength of human bones, (2) characterize the Delta-E effect in these bioscaffolds and assess its efficacy in controlling stem cell behavior, and (3) explore the magnetoelectric effect from these bioscaffolds and elucidate its efficacy in regulating stem cell behavior. An integrated education plan will train high school teachers in smart material nanosynthesis, additive manufacturing, and multiphysics material characterization, helping them enrich their classrooms with cutting-edge science topics. Furthermore, by creating project-based curricula at local high schools and introducing hands-on, service-learning courses at Boise State, the team will establish a collaborative platform, enabling local high school students, their teachers, and college students to work together on bioscaffold design, fabrication, and validation, thereby enhancing student engagement in science and technology. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.