Bibbidi Bobbidy Bone: Exploring the Magic Behind Bone Tissue Engineering BY AMRITHA ANUP '23 Cover Image: Flowchart depicting foundational steps making up the tissue engineering model. First, a biopsy is used to collect cells and tissue with regenerative potential. This is then cultivated and grown outside of the body under optimal conditions. A scaffold that is compatible with the body is developed. The collected tissue and cells are then integrated with the scaffold that can be stimulated externally to promote organized growth. This is then implanted into the patient Image Source: Wikimedia Commons
Musculoskeletal disorders are conditions that impair locomotive abilities. Many factors cause these disorders, including repetitive motions and unnatural body positions exacerbated by the modern-day workplace (Malik et al., 2018). They are estimated to affect every 1 in 2 Americans, with osteoporosis and osteoarthritis becoming more widespread (Briggs et al., 2018). Osteoarthritis is the most common form of arthritis in the U.S. (Neogi, 2013). It involves degeneration of the cartilage that lubricates joints in areas such as the hips, knees, and fingers [Figure 1A]. Another condition, rheumatoid arthritis [Figure 1A], results from an autoimmune disease in which the immune system attacks the joints. The outcome of both conditions is joint syndromes. Osteoporosis causes flash, or unannounced, fractures that are especially common in older women [Figure 1B]. Osteoporosis is estimated to cause 2 million bone fractures per year in the U.S. (Morrell et al., 2021). The chronic forms of these conditions do not have cures; treatments only work for some people, and they provide only short-term relief. Surgeries, such as joint replacement and bone grafting procedures, come with concerns of immune
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rejection, are not widely available, and have a high risk of infection due to potential pathogen transfer (Seong et al., 2010; Henkel et al., 2013). Bone tissue engineering introduces a personalized approach to treating these conditions and aims to replicate and stimulate the body’s healing process through the introduction of biocompatible materials. These are materials that mimic or come from living tissues and they do not cause undesirable effects (Kowalczuk, 2020). These cells are collected from the patient and grown in an organized manner outside of the body using a scaffold [Figure 2]. A scaffold is critical in supporting the transformation from a twodimensional layer of cells to a three-dimensional tissue (Swenson, 2013). They are typically made of a biocompatible material, or a material that is safe to put into the body, such as the polyester scaffold poly(ε-caprolactone), or PCL (Dwivedi et al., 2020). This tissue is then implanted into the patient. The final tissue product requires the integration of three components (Quarto & Giannoni, 2016): 1. an osteogenic or osteoinductive environment – this is an environment that supports bone formation and communication between DARTMOUTH UNDERGRADUATE JOURNAL OF SCIENCE
