Fundamental Biomaterials: Ceramics

Sabu Thomas, Preetha Balakrishnan, M.S. Sreekala, Sreekala Meyyarappallil Sadasivan

• Publisher: Woodhead Publishing
• Year: 2018
• Print ISBN: 9780081022030
• eBook ISBN: 9780081022047
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Fundamental Biomaterials: Ceramics provides current information on ceramics and their conversion from base materials to medical devices. Initial chapters review biomedical applications and types of ceramics, with subsequent sections focusing on the properties of ceramics, and on corrosion, degradation and wear of ceramic biomaterials. The book is ideal for researchers and professionals in the development stages of design, but is also helpful to medical researchers who need to understand and communicate the requirements of a biomaterial for a specific application. This title is the second in a three volume set, with each reviewing the most important and commonly used classes of biomaterials and providing comprehensive information on material properties, behavior, biocompatibility and applications. In addition, with the recent introduction of a number of interdisciplinary bio-related undergraduate and graduate programs, this book will be an appropriate reference volume for large number of students at undergraduate and post graduate levels - Provides current information on findings and developments of ceramics and their conversion from base materials to medical devices - Includes analyses of the types of ceramics and a discussion of a range of biomedical applications and essential properties, including information on corrosion, degradation and wear, and lifetime prediction of ceramic biomaterials - Explores both theoretical and practical aspects of ceramics in biomaterials

1

Bioceramics—An introductory overview

K. Shanmugam; R. Sahadevan Anna University, Chennai, India

Abstract

Past two decades, the significant development of biomaterials for engineering calcified tissues and regeneration of soft and hard tissues has been observed. An increase in elder population with age-related ailments and disease motivates the need for novel biomaterials that could replace damaged tissues, promote the body’s regeneration potential, and lead to an effective calcification in the hard tissue. Bioceramics (e.g., calcium phosphates, bioactive glasses, and glass-ceramics) are used to design and fabricate a scaffold of desired structures for the repair/restore/reconstruction/regeneration of diseased parts of the body, have a high potential for mimicking like a structure of the native calcified tissue. More recently, these biomaterials have also revealed promising applications in the field of engineering of calcified tissues. This chapter explores an overview of bioceramics and its fundamental requirements for biomedical applications, a detailed picture of recent developments of bioceramics and composites, including tissue engineering and drug delivery. Future research is also highlighted at the end of this chapter, with the development of tissue engineering scaffolds exploiting nanotechnology.

Keywords

Biomaterial; Bioceramics; Bioinert ceramics; Bioactive ceramics; Tissue engineering

1.1 Introduction

The treatment of damaged organs or tissue by either disease or physical/ chemical/ biological destruction leads to the development of novel materials, which acts as an implant or scaffold for an injured organ and promotes the regeneration of numerous tissues to decrease dependence on transplantation of tissue and organs. Developing new biomaterials to improve the human life standards by replacing dysfunctional organs or restoring the tissue by regenerating it with scaffolds is a global problem. As the population increased exponentially, there is a huge requirement of biomaterials, which are capable of regenerating and restoring or replace soft and hard tissues such as skin, bones, cartilage, blood vessels, including an organ. Currently, many materials are being used in the regenerative medicine notably drug delivery vehicles, porous scaffolds for tissue engineering constructs, device-based therapies and materials for bioimaging to investigate the disease progress. Many materials made of organic and inorganic have been particularly fabricated and implemented in the drug delivery and scaffolds for tissue regeneration [1].

Many definitions for biomaterial have been proposed and endorsed. The term biomaterial could be defined as “is a systemically, pharmacologically inert substance designed for implantation within or incorporation with a living system” [1a] or “a nonviable material used in a medical device, intended to interact with biological system” [1b]. In this definition, if the word “medical” would be removed, the term becomes more applicable and broader than suggested above. According to the National Institute of Health, USA., The biomaterial is defined as “any substance or combination of substances, other than drugs, synthetic or natural in origin, which can be used for any period of time, which augments or replaces partially or totally any tissue, organ or function of the body, in order to maintain or improve the quality of life of the individual” [2]. A complementary definition is necessary while dealing with the understanding of biomaterials is “biocompatibility.” It is defined as “the ability of a material to perform with an appropriate host response in a specific application” [1b]. Additionally, Biomaterials should have appropriate host response, which means that a good resistance to blood clotting and bacterial colonization or biofilm formation and leading to the normal healing process in tissue engineering applications. Biomaterials unquestionably promote the quality of human life and extend numerous people lives each year. The range of biomaterials applications in the treatment of disorders of humans is uncountable and incomparable with other treatments and therapy. It includes joint and limb replacements, artificial arteries and skin substitutes, contact lenses & corneal tissue engineering scaffolds, and bone substitutes. Therefore, an increasing demand for biomaterials arises due to the rapid development of world population. The global biomaterials market from 2016 to 2021 has a worth of USD 149.17 million by 2021 and grows from USD 70.90 Billion in 2016 to USD 149.17 million in 2021 with a compound annual growth rate (CAGR) of 16.0%. The growth depends on the exponential rise of geriatric patients, technological advancements in the implant design and fabrication, practice of hip and knee replacement and the cost of implants. Moreover, the growth of market depends based on the types of biomaterial such as polymers, metals or ceramics, its application in treatment, and region [3]. The potential value of ceramics biomaterials such as orthopedic implants currently in the market has huge demand approximately 1.5 million per annum worldwide at a cost $10 billion.

1.2 Overall classification of biomaterials

The biomaterials initially are classified based on the biocompatibility of the materials. The biocompatibility is the recognition or acceptance of the materials to be implanted/contacted with the surrounding tissues and the organs in the human body. In other words, the implants developed from natural or synthetic materials should not produce any adverse reactions to the tissue and immunological reactions to the human body. Based on biocompatibility, the biomaterials are classified into:

1. (1) Bioinert materials:
   The bioinert biomaterials refer to any materials that do produce very minimal adverse reactions to the host tissue or organs in the human body once it is contacted with physiological systems. The example of this category is stainless steel, titanium, alumina, partially stabilized zirconia, and polyethene, bioinert alumina as a dental implant. The biomaterial covered with a fibrous capsule for its functionality leads to tissue integration through the implant.
2. (2) Bioactive materials:
   The bioactive biomaterials mean that the implant materials would interact with human body through the triggering mechanism with soft tissue and leading to regeneration and repair process. For an example, the biologically active carbonate apatite (CHAp) layer formed via anion exchange reaction with body fluids is deposited on the implant. The chemical and crystallographic analysis of this layer is similar to the mineral component of the bone. Synthetic hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂], glass-ceramic A-W and Bioglass, and bioactive hydroxyapatite coating on a metallic dental, implant, surface-active bioglass bioresorbable tricalcium phosphate implant are the best examples in this category.
3. (3) Bioresorbable biomaterials:
   Bioresorbable material commonly is implantable in the human body and interacts with biological fluids, dissolving in the physiological medium and then reabsorbing into the human body via numerous metabolic processes and slowly replacing by newly forming tissue such as skin and bone. Tricalcium phosphate [Ca₃ (PO₄)₂] and polylactic-polyglycolic acid copolymers are bioresorbable biomaterials. Calcium oxide, calcium carbonate, and gypsum are considered to be as bioresorbable bioceramics.
   Secondly, the biomaterials are classified based on its source into natural and synthetic biomaterials. Furthermore, the natural biomaterials are divided into a protein- based and carbohydrate-based biomaterials. The synthetic materials are split into polymers, metals, ceramics, and composites.

1.2.1 Natural biomaterials

Prostheses are also made from natural biomaterials which are processed from an animal or...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of contributors
• 1: Bioceramics—An introductory overview
• 2: Development of ceramic-controlled piezoelectric devices for biomedical applications
• 3: Maxillofacial bioceramics in tissue engineering: Production techniques, properties, and applications
• 4: Ceramic biomaterials for tissue engineering
• 5: Inert ceramics
• 6: Bioactive glass-ceramics
• 7: Bioceramics as drug delivery systems
• 8: Bioceramics in orthopaedics: A review
• 9: Corrosion of ceramic materials
• 10: Nanostructured bioceramics and applications
• 11: Synthesis, microstructure, and properties of high-strength porous ceramics
• 12: Bioactive ceramic composite material stability, characterization, and bonding to bone
• 13: Calcium-orthophosphate-based bioactive ceramics
• 14: Effects of the biological environment on ceramics: Degradation, cell response, and in vivo behavior
• 15: Toxicity of nanomaterials to biomedical applications— A review
• Index