ABSTRACT
In the United States, there are over 500,000 bone grafts per year to replace or repair diseased or damaged bone. Autologous bone graft has long been considered the clinical “gold standard.” Harvest of autograft, however, can lead to complications including chronic harvest site pain, infection, nerve damage, cosmetic deformity, and hemorrhage. In addition, autograft harvest increases operative time and cost. Allograft (e.g., cadaver bone), has been proposed as an effective alternative; yet, this material is also plagued by problems including immunogenicity, viral transmission, compromised physiologic and biomechanical properties, and potentially limited supply. Metal implants are frequently used for these purposes, but they cannot perform as efficiently as a healthy bone, and metallic structures cannot remodel with time. To help address the need for better bone substitutes, bone tissue engineers seek to create synthetic, three-dimensional bone scaffolds made from polymeric materials incorporating cells or growth factors to induce the growth of normal bone tissue. The following chapter describes the role of polymers in tissue regeneration, with an emphasis on bone, nerve, and skin regeneration. This chapter also describes the fabrication of tissue-engineered scaffolds, and the use of polymer microspheres to deliver growth factors in bone tissue engineering applications.
