Drug-Eluting Medical Implants

Abstract

Drug-eluting medical implants are actually active implants that induce healing effects, in addition to their regular task of support. This effect is achieved by controlled release of active pharmaceutical ingredients (API) into the surrounding tissue. In this chapter we focus on three types of drug-eluting devices: drug-eluting vascular stents, drug-eluting wound dressings and protein-eluting scaffolds for tissue regeneration, thus describing both internal and external implants. Each of these drug-eluting devices also presents an approach for solving the drug release issue. Most drug-eluting vascular stents are loaded with water-insoluble antiproliferative agents, and their diffusion from the device to the surrounding tissue is relatively slow. In contrast, most drug-eluting wound dressings are loaded with highly water-soluble antibacterial agents and the issue of fast release must therefore be addressed. Growth factor release from scaffolds for tissue regeneration offers a new approach of incorporating high-molecular-weight bioactive agents which are very sensitive to process conditions and preserve their activity during the preparation stage. The drug-eluting medical implants are described here in terms of matrix formats and polymers, incorporated drugs and their release profiles from the implants, and implant functioning. Basic elements, such as new composite core/shell fibers and structured films, can be used to build new antibiotic-eluting devices. As presented in this chapter, the effect of the processing parameters on the microstructure and the resulting drug release profiles, mechanical and physical properties, and other relevant properties, must be elucidated in order to achieve the desired properties. Newly developed implants and novel modifications of previously developed approaches have enhanced the tools available for creating clinically important biomedical applications.

The effect of metronidazole releasing polymer coatings on in vitro biofilm formation

“…The study showed that the coating was depleted for chlorhexidine after two and tetracycline after seven days , respectively. Xing et al [27] analyzed the antibacterial effect of doxycycline-coated dental abutments and observed reduced biofilm formation on the functionalized surfaces. Similar to the the results of our study, a high drug-load was essential for keeping up antibacterial activity over a prolonged period of time.…”

Designing the Biocompatibility of Biohybrids

“…These functionalized surfaces may contain elements of the extracellular matrix, ceramics, ions or 292 F. Witte et al synthetic polymers responsible for an enhanced osseointegration, especially for improving the adhesion of osteoblasts [47][48][49], bioactive proteins which serve as growth factors [50,51], antiinflammatory proteins [52] or antimicrobial substances to prevent biofilm production [53,54].…”

Identifying Intracellular pDNA Losses From a Model of Nonviral Gene Delivery

“…The desired outcome when cells are exposed to the pDNA packets is for each cell to direct the pDNAs to the cell nucleus and produce the protein in relevant levels for applications in gene therapeutics [61], [62], diagnostics and functional genomics [63], [64], medical devices [65], and tissue engineering [66], [67]. However, the primary transmission as described (Fig.…”