Advances of Textiles in Tissue Engineering Scaffolds
175
6 Conventional Textiles Used for Preparation of Scaffolds
6.1 Silk Based Scaffolds
Silk fibres are known to the textile industry as the naturally elegant, lustrous and
also strong fibres which have everlasting demand in the textile industry. Hence silk
is also known to the industry as “Queen of fibres”. The silk consist of two proteins
sericin which is the waxy outer covering the inner fibroin protein. Since the last
two decades the silk protein has attracted many bio-material scientists. The fibroin
protein is explored to a larger extent than the sericin though the use of sericin as
biomaterial for tissue engineering is also an area of interest among the researchers
[30].
6.1.1 Characteristics of Silk
As a fibre, silk has many distinct and useful properties which sustained the use of
silk in textile industry. The use of silk as a bio-material attracted the researchers due
to some of these various properties. The important characteristics of silk fibroin that
has made it popular among the biomaterial scientists can be summarised as follows:
• The most favourable property of the silk protein is its ability to get in aqueous
mediums for the film formation or other forms of material and further processing it
into insoluble form without much difficulty. Processing in water base is favourable
for loading of sensitive drugs and biosensors. Thus, material based on silk can be
prepared using water as solvent under the normal atmospheric condition using
neutral pH and without applying any shear force.
• Conformational transition of α-helix and random coil to highly stable β-sheets
can be done through water vapour annealing, mechanical stretching and ultrasonic
treatments can be done in silk. This enables the prepared silk forms with good
resistance to dissolution, thermal and enzymatic degradation. Genetically alterable
composition and sequence to moderate specific features, such as molecular weight,
crystallinity and solubility can also be performed on silk to increase the resistance.
• Combination of physical properties of silk that rival many high performance fibers.
This is mainly due to the balance between the modulus, breaking strength and
elongation.
• Considerably slower rates of degradation in vitro and in vivo as compared to
the synthetic biomaterials eminent today are useful in biodegradable scaffolds in
which slow tissue in-growth is desirable. The bioresorption ability of the silk is
also very high without any harmful acidic bi-products as produced by polylactides
or polyglycolides [31].
• Enhanced environmental stability of silk fibers in comparison to globular proteins
due to the extensive hydrogen bonding and crystallinity are also favourable factors
for the use of silk as tissue scaffold.
175
6 Conventional Textiles Used for Preparation of Scaffolds
6.1 Silk Based Scaffolds
Silk fibres are known to the textile industry as the naturally elegant, lustrous and
also strong fibres which have everlasting demand in the textile industry. Hence silk
is also known to the industry as “Queen of fibres”. The silk consist of two proteins
sericin which is the waxy outer covering the inner fibroin protein. Since the last
two decades the silk protein has attracted many bio-material scientists. The fibroin
protein is explored to a larger extent than the sericin though the use of sericin as
biomaterial for tissue engineering is also an area of interest among the researchers
[30].
6.1.1 Characteristics of Silk
As a fibre, silk has many distinct and useful properties which sustained the use of
silk in textile industry. The use of silk as a bio-material attracted the researchers due
to some of these various properties. The important characteristics of silk fibroin that
has made it popular among the biomaterial scientists can be summarised as follows:
• The most favourable property of the silk protein is its ability to get in aqueous
mediums for the film formation or other forms of material and further processing it
into insoluble form without much difficulty. Processing in water base is favourable
for loading of sensitive drugs and biosensors. Thus, material based on silk can be
prepared using water as solvent under the normal atmospheric condition using
neutral pH and without applying any shear force.
• Conformational transition of α-helix and random coil to highly stable β-sheets
can be done through water vapour annealing, mechanical stretching and ultrasonic
treatments can be done in silk. This enables the prepared silk forms with good
resistance to dissolution, thermal and enzymatic degradation. Genetically alterable
composition and sequence to moderate specific features, such as molecular weight,
crystallinity and solubility can also be performed on silk to increase the resistance.
• Combination of physical properties of silk that rival many high performance fibers.
This is mainly due to the balance between the modulus, breaking strength and
elongation.
• Considerably slower rates of degradation in vitro and in vivo as compared to
the synthetic biomaterials eminent today are useful in biodegradable scaffolds in
which slow tissue in-growth is desirable. The bioresorption ability of the silk is
also very high without any harmful acidic bi-products as produced by polylactides
or polyglycolides [31].
• Enhanced environmental stability of silk fibers in comparison to globular proteins
due to the extensive hydrogen bonding and crystallinity are also favourable factors
for the use of silk as tissue scaffold.