Student Presenter(s): Shebin Tharakan
Faculty Mentor: Catherine Tolvo
Department: Clinical Sciences
School/College: College of Osteopathic Medicine, Long Island

Bone fractures in the elderly are expected to increase 87% by 2025. While bone autografts and allografts are used for critical size defect treatment, alternative approaches are critical due to donor site infection, limited supply, and patient compliance. Three-dimensional (3D) bioprinting is capable of creating biological or synthetic constructs that provide a novel route for applications in bone-implant systems. These 3D printed scaffolds can contain growth factors and stem cells to enhance bone regeneration. Adipose-derived stem cells (ADSCs) can differentiate into the osteoblast lineage and are easily harvested from adipose tissue making them desirable over bone-marrow stem cells which require an intensive harvesting process. Alginate and collagen composites have shown promising results for fracture healing; making them potential candidates for cell-laden scaffolds. Furthermore, studies have shown strontium, a calcium analog, to enhance osteogenesis while inhibiting bone resorption by osteoclasts. Our study aims to determine osteoblast behavior when coupling strontium with human ADSCs in alginatecollagen composite scaffolds. The viability of the stem cells before differentiation is measured through an MTT assay at 1, 4, and 7 days post-printing to confirm no adverse effects from the biomaterials or the printing process. Following this, differentiated cells are analyzed by Raman Spectroscopy at 7, 14, and 21 days post-printing to study the presence of biomineralization.