Silk Biomaterials for Tissue Engineering and Regenerative Medicine

Subhas C. Kundu

• Publisher: Woodhead Publishing
• Year: 2014
• ISBN:
  9780857097064
• Topic: Biological Sciences
• Subtopic: Biotechnology
• Index: Biological Sciences

Silk is increasingly being used as a biomaterial for tissue engineering applications, as well as sutures, due to its unique mechanical and chemical properties. Silk Biomaterials for Tissue Engineering and Regenerative Medicine discusses the properties of silk that make it useful for medical purposes and its applications in this area.

Part one introduces silk biomaterials, discussing their fundamentals and how they are processed, and considering different types of silk biomaterials. Part two focuses on the properties and behavior of silk biomaterials and the implications of this for their applications in biomedicine. These chapters focus on topics including biodegradation, bio-response to silk sericin, and capillary growth behavior in porous silk films. Finally, part three discusses the applications of silk biomaterials for tissue engineering, regenerative medicine, and biomedicine, with chapters on the use of silk biomaterials for vertebral, dental, dermal, and cardiac tissue engineering.

Silk Biomaterials for Tissue Engineering and Regenerative Medicine is an important resource for materials and tissue engineering scientists, R&D departments in industry and academia, and academics with an interest in the fields of biomaterials and tissue engineering.

• Discusses the properties and applications of silk for medical purposes
• Considers pharmaceutical and cosmeceutical applications

Part I

Fundamentals, processing and types of silk biomaterials

Outline

Chapter 1: Introduction to silk biomaterials

Chapter 2: Applications of silk biomaterials in tissue engineering and regenerative medicine

Chapter 3: Processing of Bombyx mori silk for biomedical applications

Chapter 4: Silk nanostructures based on natural and engineered self-assembly

Chapter 5: Electrospun silk sericin nanofibers for biomedical applications

Chapter 6: Silk fibroin microfiber and nanofiber scaffolds for tissue engineering and regeneration

Chapter 7: Silk powder for regenerative medicine

1

Introduction to silk biomaterials

D. Naskar, R.R. Barua, A.K. Ghosh and S.C. Kundu, Indian Institute of Technology Kharagpur, India

Abstract:

The term ‘silk’ makes almost all of us think first of lustrous and shimmery fabrics. This chapter discusses in brief the history of the evolution of silk from China and how silks spread to the rest of the world. It describes the different types of mulberry and non-mulberry silkworm species, their habits and habitats. This chapter briefly describes silk protein sericins (glue proteins) and fibroins produced by different silkworms as well as silk protein encoding genes. It also outlines the different diseases of silkworms and, finally, different applications of silk proteins in the core fields of biomedical engineering.

Key words

silk history

mulberry

non-mulberry

sericin

fibroin

silkworm diseases

1.1 Introduction

It is a well-known fact that silk, commonly known as the ‘queen of all fabrics’, was first discovered in China (Columbia Encyclopedia, 2000). Silk production, or ‘sericulture’, has a long and colorful history. According to the Confucian testimonial, the use of Bombyx mori silkworm cocoons and their silk production can first be dated to around 2700 bce in China, although archeologists have speculated that the history of silk cultivation can be traced back to the Yangshao period (5000–3000 bce) (Barber, 1992). Chinese history popularly described Lady Hsi-Lin-Shih (wife of the Yellow Emperor, Shi Huang di) as having tea one day under a mulberry tree when a cocoon fell into her cup. She observed that the cocoon spun a strong continuous thread which could be reeled and used as weaving thread (The Silk Association of Great Britain, 2007). From this point onwards silk has been woven specifically for royal families and became a symbol of royalty and wealth, and for more than 2000 years China kept the secret of silk. During the Shang dynasty, the production and use of silk reached its peak in craftsmanship, displaying the brightness of dyes and the perfectly honed skill of embroidery (People’s Daily Online, 2007).

Silk culture later spread to Korea, first at around 200 bce, with the movement of migrants, and from there gradually extended to other parts of Asia and Europe, such as Japan, India and Persia at around 300 bce (Qin, 2006). Another story relates the first time silk crossed the border from China, as early as 552 bce (Maltretus, 1729). When Zhang Qian served as the Chinese ambassador, two Persian monks visited China as missionaries, and silkworm eggs were secretly transported by them to Constantinople inside their walking canes. Another similar story relates the first time silk had been smuggled through the border of Japan to reach Europe. In this case, a student brought the eggs to Europe. In this way Europe could be seen to profit from the silk industry through a case of fraud in ancient times (Wardle, 1881). During the seventh century, silk was spread to Arabia, Africa, Sicily and Spain and by the thirteenth century it finally reached Italy. Silk materials and other valuable fabrics were transported to the west along the famously prosperous ‘Silk Road’ (the term coined in 1877 by Ferdinand von Richthofen, a well-known German geographer); this was a 4000 mile-long road which linked China with the Roman Empire (Eliseeff, 1998). In this way the silk trade was promoted for the cultural as well as economic exchange between the East and West. Besides its use in cloths at that time, silk was also used in the production of various other luxury objects such as handkerchiefs, wallets and wall hangings, and also for other less decorative purposes such as papers, fishing cords, bowstrings and strings for musical instruments (Meyer, 2000).

Silkworms, their eggs and the technology of sericulture were first introduced to India by Buddhist monks, and by the princess who married the king of Khotan, in Tibet (Hill, 2009). About two and half centuries ago silk was introduced in Karnataka by the ruler Tipu Sultan, and then spread to Tamil Nadu in the early 1960s. This area is now considered one of the most important regions for silk production in India (R. T. I. act, Chapter 18, 2012). The archeological evidence found in Harappa and Mohenjo-Daro gave rise to some interesting discoveries. The evidence found in these regions suggests that sericulture was also being practiced in South Asia in the Indus Valley Civilization, which was almost contemporary with production in China (Good et al., 2009).

Analysis of silk production distribution worldwide has shown that China is the largest producer of silk, producing 79.1% of the total worldwide raw silk production. India is the second largest producer after China, and produces 17.5% of the total worldwide raw silk production. Japan, Brazil, Korean Republic, Uzbekistan, Thailand and Vietnam follow as other significant producers of raw silk materials (Antha, 2011). Major silk producing states in India are Karnataka, Tamil Nadu, Andhra Pradesh, West Bengal, Madhya Pradesh, Jammu and Kashmir, Maharashtra, Manipur, Mizoram and Assam, while other states in India also produce a little silk (TNAU Agritech Portal, 2012). This chapter deals with the various species of silkworms, their products and different uses.

1.2 General information about silkworms

A wide variety of natural silks from hundreds of different silkworm species are available throughout the world. Among these, the family Bombycoidea consists of eight families of which Bombycidae and Saturniidae are commercially important, as shown in Table 1.1. The family Bombycoidea silkworm silk is categorized as ‘mulberry’, while the Saturniidae fall under the category of ‘non-mulberry’.

Table 1.1

Main mulberry and non-mulberry silkworms found particularly in India

Silks	Main silk species	Biological name	Main food plants	Distribution, shown mainly in Indian states	Voltinism (number of crops in a year)	Cocoon color(s)
Mulberry		Bombyx mori	Morus alba, M. australis, M. nigra, M. atropurpurea, M. cathayana, M. liboensis, M. macroura, M. notabilis, M. serrata, M. tillaefolia and other Morus spp.	Mainly in Karnataka, Andhra Pradesh, West Bengal, Tamil Nadu and Jammu and Kashmir	Uni- (1 crop), bi- (2 crops) and multivoltines (4–5 crops)	Mostly dark, pale yellow and white
Nonmulberry	Tropical tasar Oak tasar (temperate tasar) Chinese Oak tasar	Antheraea mylitta (largest cocoon) A. proylei A. roylei A. frithi A. pernyi	Terminalia arjuna, T. tomentosa, Shorea robusta, Quercus incana, Q. serrata, Q. semicarpifolia, Q. himalayana and other Quercus spp.	Tropical parts of India mainly Andhra Pradesh, Bihar, Jharkhand, Madhya Pradesh, Orissa, Uttar Pradesh, West Bengal. Manipur, Nagaland, Assam, Sub-Himalayan belt, Jammu and Kashmir, Himachal Pradesh China	Bivoltine, trivoltine (3 crops)	Yellow/grey/ dark brown; golden light brown; double layers white; pale spotted dark brown; light brown; all single layer
	Fagaria tasar	Attacus atlas (largest moth)	Maesa indica Evodia fraxinifolia	Assam, Nagaland, Mizoram	Bivoltine	Uneven shaped, spotted dark brown
	Muga	Antheraea assamensis (assama)	Litsea polyantha, L. citrate, L salicifolia, Persea bombycina	Assam (more than 95%), Meghalaya, Nagaland, Manipur, West Bengal	Multivoltine	Single layer, vibrant light brown; golden
	Eri (semidomesticated)	Samia (Philosamia) ricini	Ricinus communis Heteropanax fragrans Evodia fraxinifolia Manihot esculenta	North-east ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributor contact details
• Woodhead Publishing Series in Biomaterials
• Foreword
• Part I: Fundamentals, processing and types of silk biomaterials
• Part II: Properties and behaviour of silk biomaterials
• Part III: Tissue engineering, regenerative medicine and biomedical applications of silk biomaterials
• Index