Factors affecting protein structures and properties, formation of monolayers, forces influencing protein interactions and how proteins are adsorbed on different biomaterial surfaces are presented in this chapter. In addition, some of the commonly used methods to understand the behavior of adsorbed proteins are briefly discussed.

The chapter presents the fundamentals and importance of sterilization. Different methods used to sterilize medical implants are discussed, together with the principles behind determining the type of sterilization method suitable for an application.

Memory is vital for a range of brain functions, not just decision-making. Memory is a complex concept, that many researchers have attempted to model and explain over the course of history, all with their own properties. It is commonly accepted however that memory must include both retention and retrieval. Human memory can be considered as a complex storage system, in which information can be stored and accessed according to different criteria. Various models have explained memory organisation in terms of duration of retention (fractation), information type and temporal direction. To gain an insight into how memory informs decision-making, we must consider it as a dynamic cognitive function, with three main stages: encoding, storage and retrieval.

Different types of biocompatibility testing such as cytotoxicity; sensitization; irritation acute, subacute, subchronic, and chronic systemic toxicity; pyrogenicity; genotoxicity; implantation; hemocompatibility; carcinogenicity; reproductive and developmental toxicity are discussed in this chapter.

This introductory chapter provides a brief history of biomaterials, and the emphasis over the years on ensuring the viability of implants for the desired time and their interaction with the biology of the body. It discusses the importance of first understanding the type of chemical bonds that hold atoms together and how these bonds impart physical, chemical, and mechanical properties to the materials. These properties render biomaterials more or less appropriate for different medical applications as well as determine the body’s response to them.

Different surface modification techniques to modify surfaces of medical devices including principles underlying these surface modification techniques and advantages and limitations of each technique are discussed in this chapter.

The human brain follows a clear and reliable timeline of development. Various stages of development are key to specific functions. Decision-making, due to its complexity, cannot be pinpointed to one age in development or a critical period, it undergoes several key stages through the lifespan. In the prenatal stage, myelination is important for cognitively demanding tasks like decision-making. In the newborn stage, the baby is constantly forming new synapses, increasing connectivity. During childhood most children develop the ability to use logic in decisions. Adolescence is a critical period for synaptic pruning, improving efficiency. The prefrontal cortex is considered fully mature in adulthood, around the age of 25.

The bipolar junction transistor is introduced and its operation is explained. DC and switching applications are given. The need for DC biasing for AC amplification is illustrated and then satisfied by the Universal DC bias circuit. The thermal stability of this circuit is discussed and resulting constraints on resistor selection are developed. Amplifier gain, input impedance, and output impedance are defined and their usefulness is explained. The AC equivalents for the bipolar transistor are developed and then used to derive the properties of the common-emitter, common-collector, and common-base amplifiers. The concepts of distortion and feedback are introduced.

Key components of the extracellular space together with the principal proteins and pathways that cells utilize to interact, different adhesion mechanisms, and the role of cell material environment are discussed in this chapter.

This chapter presents the cellular environment and encompasses a diverse population of control systems that range from biomolecular phenomena to a remarkably complex coordination of signaling pathways. Discussions include the principal functions of the plasma membrane, major classes and operation of cell junctions, cell signaling pathways, and secondary messengers. In addition, common biological testing techniques in biology–biomaterial interactions are also discussed.

The operational amplifier is introduced and the basic rules for its operation are given. Nonlinear operation is explained and the golden rules for linear operation are derived. Several examples of linear operation are given, including amplifiers, buffer, adder, differential amplifier, integrator, and differentiator. Practical considerations for using op-amps are discussed, including bias currents, offset voltages, slew rate limits, and frequency response. As a final non-linear example, an oscillator circuit, the astable multivibrator, is presented and analyzed.