Implants future trends

Basic research in ion implantation is slowly moving its empliasis from the semiconductor field to the field of material science, as already mentioned in the introduction. Accordingly, the chemical aspects of ion implantation are gaining more importance and interest. Since the chemical studies represent up to now only a small part of the work done, there is an extraordinarily extensive area of science awaiting future activity. In this short final chapter I shall try to point out the domains of special interest for basic science as well as for applications. The description of future trends is naturally not objective but reflects the personal view of the author. 

As a result of the shortcomings of current insulin therapy, much work has been directed toward developing polymeric controlled release systems that can be implanted or injected into the body to achieve glucose control in patients with diabetes. This chapter will review the history of such systems and will discuss ciurent technology and future trends for the sustained delivery of insulin for the treatment of diabetes mellitus. Several media serving as carriers include synthetic absorbable polymers, biomolecules, and ceramics. 

In this chapter, we focus on recent efforts to design and fabricate soft shape-memory materials, including both polymeric and supramolecular systems. We first classify these materials based on their micro- and nanostructure (Section 5.2.2). We then highlight how soft shape-memory materials have been applied to biomedical applications as implantables (Section 5.2.3.1), drug delivery devices (Section 5.2.3.2), and tissue engineering scaffolds (Section 5.2.3.3). In addition, we briefly discuss future trends for utilizing soft shape-memory materials for biomedical applications (Section 5.2.4). 

Wear is defined as the loss of material from a surface as the result of relative motion. In this chapter, the wear processes in polymer implants are discussed. Polymers are used in a wide variety of implants in the human body such as joint replacement implants, pacemakers, catheters and heart valves. Wear of polymer implants is almost exclusive to joint replacement implants, such as those used to replace the hip or knee. These implants involve the articulation of a metal or ceramic against a polymer. Typically these implants operate with a mixed or boundary lubrication regime and, therefore, there is contact between the bearing surfaces that can lead to the generation of wear debris. The chapter is divided into sections that cover implants, wear processes, polymers used in implants, the effect of wear debris on the body and, finally, likely future trends. 

In this chapter, various materials that can be used as coatings for biomedical implants are discussed. Key techniques to produce these coatings are briehy explained, followed by discussions about the mechanisms of cell—material interactions. Then, typical examples are provided to illustrate how the surface properties of coatings affect cell—material interactions. Finally, challenges and future trends in developing new coatings for long-term clinical success are discussed. 

The recent developments of the wireless implantable and wearable biosensors for POC applications enable dedicated patient health management. The future trends for POC biosensors outline the need for smaller and flexible integrated systems, new biocompatible materials applicable for different applications, new packaging techniques, energy-efficient wireless systems, improved antenna designs, and efficient wireless power transfer and energy-harvesting techniques. 

Another important trend in the future will be the improvement in the biological properties of bone substitutes, the aim being to transform a bone defect into new mature bone as fast as possible. This implies that the focus will be set on resorbable materials that possess an open-porous structure allowing cells to invade the structure. Another potential focus could be set on osteoinductive ceramics. A number of authors have indeed observed that ceramic bone graft substitutes implanted under the skin or in muscles are filled or coated with bone over time. However, despite very intensive research, there is only a poor understanding of the mechanisms leading to osteoinduction, and as a result, it is not possible at the moment to design an osteoinductive ceramic. 

Krewson, C., and Saltzman, W. M., 1994, Targetting of peptides and proteins in the brain following release from implantable polymers, in Trends and Future Perspectives in Peptide and Protein Drug Delivery (V. H. D. Dee, M. Hashida, and Y. Mizushima, eds.), Harlans Academic Publishers, Dondon, pp. 273-294. 

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