Biomedical, Therapeutic and Clinical Applications of Bioactive Glasses

Gurbinder Kaur

• Publisher: Woodhead Publishing
• Year: 2018
• Print ISBN: 9780081021965
• eBook ISBN: 9780081021972
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Biomedical, Therapeutic and Clinical Applications of Bioactive Glasses is an essential guide to bioactive glasses, offering an overview of all aspects of the development and utilization of this cutting-edge material. The book covers vital issues, including mesoporosity, encapsulation technologies, scaffold formation and coatings for a number of applications, including drug delivery, encapsulation, scaffolds and coatings. Readers will gain a strong understanding and practical knowledge of the therapeutic aspects of bioceramics, with a focus on glasses from a clinical point-of- view. Researchers, students and scientists involved in bioceramics, bone tissue engineering, regeneration and biomedical engineering will find this to be a comprehensive resource.- Presents detailed coverage of bioactive glasses, including technologies and applications- Includes all the major development areas related to bioactive glasses, enabling readers to understand the latest research- Considers the potential future developments of bioactive glasses as a drug carrier

Part I

Fundamentals of Bioactive Glasses

Chapter 1

Bioactive Glass Containing Coatings by Electrophoretic Deposition: Development and Applications

Svenja Heise; Laura Ramos Rivera; Aldo R. Boccaccini Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Erlangen, Germany

Abstract

This chapter describes the development of bioactive glass (BG)-based coatings by electrophoretic deposition (EPD). The fundamentals of EPD, relevant deposition theories, and the influencing processing parameters are discussed. Subsequently, different coating techniques related to EPD are presented. The chapter includes first a description of pure BG coatings achieved via EPD. Since such pure BG coatings are brittle, a subsequent thermal treatment is necessary to densify the material and to achieve improved adhesion to the substrate. An alternative approach involves adding biopolymers to BG particles forming organic-inorganic composite coatings, which avoids high-temperature treatment. Depending on the polymer used, a sintering step can thus be avoided and the complete coating process takes place at room temperature. Some of the polymers used for the EPD of BG-polymer coatings are discussed. It is highlighted that this type of organic-inorganic coatings can be functionalized with the incorporation of therapeutic drugs, for example, antibiotics to defeat infections or growth factors to promote tissue formation, which represents one of the key advantages of the use of EPD, a room temperature process, to produce bioactive and antibacterial BG-based coatings. Finally, the chapter concludes with a summary of well-established characterization methods applied on electrophoretically deposited BG-based coatings.

Keywords

Electrophoretic deposition; Bioactive glasses; Composite coatings; Thermal treatment; Bioactivity; Drug release; Hydroxyapatite formation.

1.1 Introduction

Bioactive glasses (BGs) exhibit the capability of forming strong physical and chemical bonds with living tissue (Hench, 2015). These surface-active materials bond with soft and hard tissue through the formation of hydroxycarbonate apatite. The numerous biomedical applications realized and proposed for BGs have been discussed in the literature (Fagerlund, 2017; Miguez-Pacheco et al., 2015; Hench and Paschall, 1973; Montazerian and Zanotto, 2017; Hupa, 2011; Brauer and Möncke, 2017); most applications being related to the skeletal system, for example, as small implants in nonload-bearing applications, bone filler and scaffolds to promote new bone tissue formation, and in dentistry, although applications in soft-tissue repair are emerging (Miguez-Pacheco et al., 2015).

The first BG was invented by Hench et al. in the late 1960s (Hench and Paschall, 1973). This BG, well-known as 45S5 Bioglass, is a melt-derived glass in the Na₂O-CaO-P₂O₅-SiO₂ system, which contains thus elements which are present in the human body, specially Ca and P are abundant in bone tissue, making BG 45S5 ideal for bone regeneration. In general, BGs show a rapid initial dissolution of the alkaline elements from the surface which is followed by a precipitation of a Ca- and P-rich layer on top of the alkali-depleted SiO₂ layer, forming hydroxycarbonate apatite, the mineral phase of bone (Fagerlund, 2017).

In the last 45 years, different BGs have been developed and the production method has been extended to sol-gel glasses, requiring lower temperature during synthesis, while resulting in particles with smaller size distribution and higher surface area leading to higher bioactivity (Montazerian and Zanotto, 2017; Hupa, 2011). While melt-derived BGs are limited to a SiO₂ content ≤ 60 mol%, sol-gel glasses can have up to 90 mol% SiO₂ due to an excess of

OH groups incorporated during fabrication (Montazerian and Zanotto, 2017).

Besides different production techniques, also numerous compositions of BGs are being continuously investigated, for example, silicate, phosphate, and borate glasses, and also glass-ceramics. However, BGs are in general not suitable for load-bearing applications, such as large bone replacement implants. Therefore, for orthopedic applications, one common approach is to develop metal implants coated with BGs and glass-ceramics (Krause et al., 2006; Baino and Verne, 2017). In this w...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• Contributors
• Editor’s Biography
• Foreword
• Acknowledgments
• Part I: Fundamentals of Bioactive Glasses
• Part II: Therapeutic Applications of Bioactive Glasses
• Part III: Bioactive Glasses for Tissue Engineering and Regenerative Medicine
• Index