Implants, surface modification

Vasanthan, A., Kim, H., Drukteinis, S., and Lacefield, W. (2008) Implant surface modification using laser guided coatings in vitro comparison of mechanical properties. J. Prosthodont., 17 (5), 357 -364. 

Lamolle, S F Monjo, M Lyngstadaas, SP Ellingson, JE Haugan, HJ. Titanium implant surface modification by cathodic reduction in hydrofluoric acid surface... 

This chapter begins with a review of other UHMWPE orthopedic implant surface modifications, the properties of HA, and the medical applications of HA. The synthesis and processing of UHMWPE/H A biomateiials is then described, followed by the chemical, physical, mechanical, and tribological characterization of the UHMWPE/HA biomaterials. Finally, the sterilization, biocompatibihty, and commerciah-zation of the UHMWPE/HA biomaterials are covered. 

Surface modification of a contact lens can be grouped into physical and chemical types of treatment. Physical treatments include plasma treatments with water vapor (siUcone lens) and oxygen (176) and plasma polymerization for which the material surface is exposed to the plasma in the presence of a reactive monomer (177). Surfaces are also altered with exposure to uv radiation (178) or bombardment with oxides of nitrogen (179). Ion implantation (qv) of RGP plastics (180) can greatiy increase the surface hardness and hence the scratch resistance without seriously affecting the transmission of light. 

Wear and corrosion protection can be provided by the well-established techniques of hard-facing and plating or by surface-modification processes such as bonding, nitriding, carburizing, and ion implantation. The protection these processes afford is adequate in most environments but may fail over a period of time if the conditions are too severe. 

Ikada Y. Surface modification of polymers for medical application. Biomaterials, 1994, 15, 725-736. James SJ, Pogribna M, Miller BJ, Bolon B, and Muskhelishvili L. Characterization of cellular response to silicone implants in rats Implications for foreign-body carcinogenesis. Biomaterials, 1997, 18, 667-675. 

Bioadhesion is an area of research important in the selection of biomaterials (e.g., for implants). It is also critical in the development of the new biofouling coatings. A system for bioadhesion studies was developed, in which silicones with chemically and topologically (microengineered) modified surfaces were evaluated in the studies of the response to such surfaces of a diverse set of organisms.559-561 A new study of micropatterning and surface modification of PDMS to control bioadhesion has been reported.562... 

Polyelectrolytes have been widely investigated as components of biocompatible materials. Biomaterials come into contact with blood when used as components in invasive instruments, implant devices, extracorporeal devices in contact with blood flow, implanted parts of hard structural elements, implanted parts of organs, implanted soft tissue substitutes and drug delivery devices. Approaches to the development of blood compatible materials include surface modification to give blood compatibility, polyelectrolyte-based systems which adsorb and/or release heparin as well as polyelectrolytes which mimic the biological activity of heparin. 

In this chapter we discuss how solid surfaces can be modified. Surface modification is essential for many applications, for example, to reduce friction and wear, to make implants biocompatible, or to coat sensors [405,406], Solid surfaces can be changed by various means such as adsorption, thin film deposition, chemical reactions, or removal of material. Some of these topics have already been discussed, for example in the chapter on adsorption. Therefore, we focus on the remaining methods. Even then we can only give examples because there are so many different techniques reflecting diverse applications in different communities. 

A. Novel Surface Modifications of Conventional Orthopedic and Dental Implants... 

All electrodes react with their environment via the surfaces in ways which will determine their electrochemical performance. Properly selected surface modification can effectively enhance the electrode heterogeneous catalysis property, especially selectivity and activity. The bulk materials can be chosen to provide mechanical, chemical, electrical, and structural integrity. In this part, several surface modification methods will be introduced in terms of metal film deposition, metal ion implantation, electrochemical activation, organic surface coating, nanoparticle deposition, glucose oxidase (GOx) enzyme-modified electrode, and DNA-modified electrode. 

Since there exist quite a number of other methods for surface modification and for introducing foreign atoms into host lattices, one should discuss briefly the advantages of ion implantation ... 

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