Biocomposites: Advances in Research and Applications Chapter 2. Boron-Substituted Biomaterials

Abstract

Biomaterial scientists are interested in boron as a dopant element because of its natural functions in human hard tissues. However, boron does not exist in its elemental form in nature. Instead, it reacts with oxygen to form boric acid (H3BO3). Boron occurs naturally as borates, including orthoborate 𝐵��𝑂��3 3−, metaborate 𝐵��𝑂��2 −, or tetraborate 𝐵��4𝑂��7 2−, or as any salt containing these anions, such as sodium metaborate, 𝑁��𝑎��+[𝐵��𝑂��2]−, and borax (Na+)2[𝐵��4𝑂��7]2-. Boron exerts a range of biological effects, including impacts on reproduction and embryogenesis, promoting wound healing and enhancing responses to injury or infection, influencing calcium and bone metabolism, and benefiting central nervous function. It also affects the presence or function of various hormones, such as thyroid hormone, insulin, estrogen, and progesterone, as well as calcium, magnesium, and vitamin D, which are involved in hard tissue metabolism. Research conducted at the molecular level has demonstrated that boron can increase RNA transcription within placental nuclei and activate mRNA translation, particularly for growth factors involved in wound repair and the formation of new blood vessels (angiogenesis). This chapter will provide a summary of the recent advances in the development of boron biomaterials that respond to specific biomedical applications.