Nanobioceramics for Healthcare Applications

Eng San Thian, Jie Huang, Mamoru Aizawa

• Publisher: WSPC (EUROPE)
• Year: 2016
• ISBN:
  9781786341358
• Topic: Technology & Engineering
• Subtopic: Biomedical Science
• Index: Technology & Engineering

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This book provides a comprehensive coverage on nanobioceramics and their potential applications in healthcare. Ground-breaking new discoveries in bioceramics and their properties have meant an increasing interest in the development of how this can be related to nanobiomaterials, and in treating various conditions from osteoporosis to surgical dentistry. Research has also been driven by ageing global populations, where better restorative and reparative treatments are needed. As a consequence of this change in demographics, the research of nanobioceramics for application in healthcare is a field that is advancing at a considerable pace.

Individual chapters give the reader an in-depth coverage on the synthesis and characterization of various nanobioceramics including silica, calcium phosphates, bioglass, and glass-ceramics. Through reviewing and analysing current literature, this book provides a rich source of valuable information on nanobioceramics for any professionals and students in materials science and engineering. It is also aimed at medical professionals searching for state-of-the-art techniques and treatments available and made possible through this particular field of innovation.

--> Contents:

• Overview of Nanobioceramics (Poon Nian Lim, Jie Huang, Mamoru Aizawa and Eng San Thian)
• Silica-Based Nanoceramics (Akiko Obata and Toshihiro Kasuga)
• Bioceramics for Orthopedic Device Applications: Hydroxyapatite (Qiaomu Tian, Laura Rivera-Castaneda, Zachary S Dunn and Huinan Liu)
• Tricalcium Phosphate-Based Nanoceramics (Kazuaki Hashimoto)
• Calcium Phosphate Nanocoatings: Production, Physical and Biological Properties, and Biomedical Applications (Besim Ben-Nissan and Andy H Choi)
• Bone Cements Utilized for the Reconstruction of Hard Tissue: Basic Understanding and Recent Topics (Kanji Tsuru, Yuki Sugiura and Kunio Ishikawa)
• Strontium-Containing Mesoporous Bioactive Glass for Regeneration of Osteoporotic Bone and Periodontal Tissue (Chengtie Wu and Jiang Chang)
• Bioactive Glass-Ceramics (Taishi Yokoi, Toshiki Miyazaki, Masakazu Kawashita and Chikara Ohtsuki)
• Nanocomposites for Bone Repair (Kyung-Ah Kwon, Jennifer H Shepherd, David V Shepherd, Ismael Moreno-Gomez and Serena M Best)

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Readership: Professionals and students in materials science and engineering; medical professionals searching for state-of-the-art techniques and treatments available in nanobioceramics.
--> Key Features:

• First book to focus on nanobioceramics
• Covers all types of nanobioceramics, their processing and properties and applications

Chapter 1

Overview of Nanobioceramics

Poon Nian Lim^*,^¶, Jie Huang^†,||
Mamoru Aizawa^‡,** and Eng San Thian^*,††

^*Department of Mechanical Engineering,
National University of Singapore, 9 Engineering Drive 1,
Singapore 117576, Singapore
^†Department of Mechanical Engineering,
University of London, London WC1E 7JE, UK
^‡Department of Applied Chemistry,
School of Science and Technology,
Meiji University, 1-1-1 Higashimita, Tama-ku,
Kawasaki, Kanagawa 214-8571, Japan
^¶[email protected], ^||[email protected],
^**[email protected], ^††[email protected]

Abstract

Bone is the second most commonly transplanted organ in the human body. The concept of repairing bone injuries has evolved greatly over the last five decades to the third generation of biomaterials. One of the emerging areas of research in the third generation of biomaterials is the integration of nanotechnology into bioceramics. Due to its close chemical similarity to the human bone mineral, nanobioceramic has emerged as a new generation of biomaterials, which aims to create a micro-environment that induces enhanced cell responses leading to osteogenesis. This chapter will thus present an overview of the general characteristics of nanobioceramics. The future prospects and challenges of nanobioceramics will also be covered.

1.1Biomaterials for Bone Repair

Bone is a dynamic and complex tissue that provides structural support and withstands load-bearing for the body. Moreover, it also serves as a reservoir for minerals, supports muscular contraction for mechanical movement, and protects the internal organs.¹ Through undergoing remodelling, bone has the innate capacity to regenerate and repair itself upon damage. However, when huge amount of bone is lost in circumstances such as trauma, diseases, or old age, the function of bone is adversely affected. Under such circumstances, bone function can only be restored by surgical reconstruction. Bone repair is a procedure of replacing the defect part with material from either the patient’s own body (autografting) or that of a donor (allografting).^2,3 Autografts contain living bone cells and growth factors that offer osteogenesis and stimulate induction, hence providing bone ingrowth. Even though autograft is considered the “gold standard”, only a limited amount of bone can be harvested for use in bone repair. In relation to skeletal reconstructive surgery, an alternative has been the use of donated allogenic bone. However, processing (freezing or demineralisation) of the allografts adversely affects the structural integrity of the material and its osteoinductive and osteogenic activity. Hence, its implementation for orthopaedic applications has been hindered by the incomplete remodelling and limited availability. Furthermore, both autografting and allografting involve multiple surgeries and are often associated with the risk of a series of complications such as infection, hematoma, cosmetic disadvantages, post-operative pain, and chronic pain at the donor site.^4,5 Thus, autografts and allografts do not always provide the best solution for bone repair. Therefore, all these factors greatly drive the market for synthetic bone alternatives.

The concept of placing implants into the human body has evolved greatly over the last five decades. It began in the 1960s with the first generation of biomaterials designed to achieve matching mechanical properties of the replaced tissues, with a minimal toxic response in the host. At that time, bioinert materials are deemed biocompatible and have been used in the following two areas: (1) permanent prostheses such as hip prosthesis and dental implants and (2) fixation tools for bone fractures such as plates, pins, screws, and rods. Bioinert implants such as stainless steels, cobalt–chromium alloys, titanium alloys, alumina, and zirconia are able to provide mechanical support in load-bearing applications.

However, the body regards these bioinert materials as foreign, triggering fibroblasts to form a fibrous capsule around the implant. The formation of a protective fibrous layer isolated the implant from the host tissue, which created a separation between the implant and the host.⁶ Thus, bioinert implants could not be integrated into the bone tissue. Furthermore, there were also concerns regarding undesirable tissue responses caused by the released ions and small debris particles from the metallic and ceramics implants, respectively.⁷ In addition to the issue of undesirable responses, the high mechanical stiffness of metallic implants often resulted in stress shielding and thus bone resorption due to the mismatch of elastic modulus between the implant and bone.⁸ As a consequence, a second operation is often required to remove the failed bioinert implant. Hence, it soon becomes apparent that bioinert materials are not adequate in eliciting full tissue growth and regeneration.

With this in mind, material scientists begin to partner with physicians to develop the second generation of biomaterials. In the 1980s, this has progressed towards biomaterials that can elicit a controlled action and reaction in the physiological environment, conferring a bioactive or biodegradable behaviour. The interface problem can be resolved with bioactive or biodegradable materials. Bone can directly form an interfacial “bond” with the surface of bioactive materials with no mediation of a fibrous connective tissue interface and further undergo mineralisation. Biodegradable materials exhibit clinically relevant, controlled chemical breakdown and resorption, which can be ultimately replaced by regenerating tissues. During the last 40 years, bioceramics have received significant attention for biomedical applications due to their ability to interact with human biological system. With these favourable biological responses, a wide array of ceramic materials have been used. This ranges from chemically pure oxides to various calcium phosphate-based ceramics,⁹ bioactive glasses,¹⁰ glassceramics,¹¹ and the chemically and microstructurally complex ceramic-matrix composites.¹² These bioceramics can be fabricated in a variety of forms to serve various functions in the body repair.¹³

Calcium phosphate-based ceramics can be fabricated into porous implants, granules, powders, and coatings on metallic implants. For instance, hydroxyapatite (HA) coatings provided osteoconduction in which bones grew onto the coatings and formed mechanically strong interface.¹³ Bioactive glasses and glass-ceramics were used as middle-ear prostheses, oral implants, and vertebrae replacement for spinal tumours.¹⁴ Bioactive composite consisting of HA particles in a polyethylene matrix has become important in the repair and replacement of bones in the middle ear.¹⁵

Despite the clinical success of bioinert, bioactive, and biodegradable implants in meeting the medical needs of the rapidly aging population, 30–50% of the prostheses failed within 10–25 years, leading to revision surgeries.¹⁶ Unlike living tissues, synthetic materials cannot respond to the changing physiological loads or biochemical stimuli. Hence, this limits the lifetime of the synthetic implants. Fifty years of research in the advancement of first- and second-generation biomaterials are limited in the repair and restoration of the body and this signals the need for a shift of the current medical paradigm towards a more biological-based approach for the regeneration of tissues.

This shift occurs at the beginning of 2000s, which brings us to the third generation of biomaterials, the cell- and gene-activating biomaterials that are designed to stimulate specific cellular responses at the molecular level. Third-generation materials are not meant to substitute plainly the materials from previous generations. Instead, they improve the initial physiological cues and bio-activity existing in the second-generation biomaterials, to allow the biomaterials and surrounding environment to adapt, signal, and stimulate specific cellular activity and behaviour in order to regenerate new tissues. The aim to regenerate rather than repair leads to the exploration of tissue engineering and regenerative medicine by using natural signalling pathways and components such as stem cells, growth factors, and peptide sequences, in combination with the synthetic scaffold. Artificial tissues are being fabricated by placing cells within scaffold materials so as to guide cell proliferation and differentiation. Hence, this opens up new possibilities of treatments and applications.

Along this new wave of thinking, one of the emerging areas of research is the integration of nanotechnology into the field of bio-material science. Nanotechnology has opened up a new era of technology, particularly the development of nanostructuring and nanoscale engineering of the biomaterials. The intriguing properties of nanobiomaterials are explored in several ways. Metallic nanoparticles have found significant applications in a wide spectrum of biomedical utilities such as imaging, sensing, drug delivery, and gene targeting.^17–20 Carbon-based nanomaterials including fullerenes, nanotubes, nanodiamonds, and graphene show great promise as a carrier for pharmaceutical agents, components in nanoformulations for the delivery of therapeutic molecules, biosensor, imaging, drug delivery, bacterial inhibition, and photothermal therapy.^21–23 Polymeric nanoparticles have been used as drug carriers,^24,25 and nanobioceramics have been used extensively in orthopaedic and cranio-maxillofacial applications.²⁶ Indeed, nanotechnology has evolved rapidly from the discovery phase to the application phase; its potential impact on the healthcare is immense and has pervaded many aspects of the medical field (Table 1.1).²⁷

Driven by the increasing number of patients afflicted with traumatic and non-traumatic conditions, the demand for the reconstruc...

Table of contents

• Cover Page
• Title
• Copyright
• Preface
• About the Editors
• Contents
• Chapter 1 Overview of Nanobioceramics
• Chapter 2 Silica-based Nanoceramics
• Chapter 3 Bioceramics for Orthopaedic Device Applications: Hydroxyapatite
• Chapter 4 Tricalcium Phosphate-based Nanoceramics
• Chapter 5 Calcium Phosphate Nanocoatings: Production, Physical and Biological Properties, and Biomedical Applications
• Chapter 6 Bone Cements Utilised for the Reconstruction of Hard Tissue: Basic Understanding and Recent Topics
• Chapter 7 Strontium-Containing Mesoporous Bioactive Glass for Regeneration of Osteoporotic Bone and Periodontal Tissue
• Chapter 8 Bioactive Glass-Ceramics
• Chapter 9 Nanocomposites for Bone Repair
• Index