328
hydroxyproline content. Studies on the mechanism of action of isinglass have shown
that higher molecular weight aggregates that increase the length of the collagen
molecules (trimers, tetramers, etc.) increase effi ciency and that their surface charges
are important in the clarifi cation process,” (Hickman et al. 2000 ).
8.2 Fish Collagen as a Biomaterial
Collagen is not only easily available and highly versatile, but also possesses a major
advantage in being biocompatible and biodegradable. The use of collagens as biomaterials in biomedicine is determined by their possible degradation by human collagenases. (see for review Parenteau-Bareil et al. 2010 ; Hayashi et al. 2012 ).
Additionally, “type I collagen is a suitable material for implantation since only a
small amount of people possess humoral immunity against it, and a simple serologic
test can verify if a patient is susceptible to an allergic reaction in response to this
collagen-based biomaterial,” (Parenteau-Bareil et al. 2010 ; see also Eaglstein et al.
1999 ).
Two basic techniques are used for preparation of collagen-based biomaterials.
“The fi rst one is a decellularized collagen matrix preserving the original tissue
shape and ECM structure, while the other relies on extraction, purifi cation and
polymerization of collagen and its diverse components to form a functional scaffold,” (Parenteau-Bareil et al. 2010 ). According to Gilbert et al. ( 2006 ) three main
methods are used for tissue decellularization:
“ Physical methods include snap freezing that disrupt cells by forming ice crystals,
high pressure that burst cells and agitation, that induce cell lysis and are used
most often in combination with chemical methods to facilitate penetration of
active molecules in the tissue.
Chemical methods of decellularization include a variety of reagents that can be
used to remove the cellular content of ECM. These substances range from acid
to alkaline treatments, as well as chelating agents such as EDTA, ionic or nonionic detergents and solutions of extreme osmolarity.
Enzymatic treatments such as trypsin, which specifi cally cleaves proteins and
nucleases that remove DNA and RNA are also commonly used to produce acellular scaffold. However, none of these methods can produce an ECM completely
free of cellular debris and a combination of techniques is often required to obtain
a material free of any cell remnant,” (Parenteau-Bareil et al. 2010 ).
There are several types of collagen-based biomaterials of fi sh origin: gels,
scaffolds, sponges, fi lms, membranes etc.
Collagen Gels In contrast to marine chitosan gels, which are well investigated with
respect to tissue engineering, fi sh collagen gels possess some limiting factors. For
example, the low denaturation temperature (Td) of most fi sh collagens with the
exception of shark collagen (Nomura et al. 2000a , b ), renders these structural
8 Marine Collagens
hydroxyproline content. Studies on the mechanism of action of isinglass have shown
that higher molecular weight aggregates that increase the length of the collagen
molecules (trimers, tetramers, etc.) increase effi ciency and that their surface charges
are important in the clarifi cation process,” (Hickman et al. 2000 ).
8.2 Fish Collagen as a Biomaterial
Collagen is not only easily available and highly versatile, but also possesses a major
advantage in being biocompatible and biodegradable. The use of collagens as biomaterials in biomedicine is determined by their possible degradation by human collagenases. (see for review Parenteau-Bareil et al. 2010 ; Hayashi et al. 2012 ).
Additionally, “type I collagen is a suitable material for implantation since only a
small amount of people possess humoral immunity against it, and a simple serologic
test can verify if a patient is susceptible to an allergic reaction in response to this
collagen-based biomaterial,” (Parenteau-Bareil et al. 2010 ; see also Eaglstein et al.
1999 ).
Two basic techniques are used for preparation of collagen-based biomaterials.
“The fi rst one is a decellularized collagen matrix preserving the original tissue
shape and ECM structure, while the other relies on extraction, purifi cation and
polymerization of collagen and its diverse components to form a functional scaffold,” (Parenteau-Bareil et al. 2010 ). According to Gilbert et al. ( 2006 ) three main
methods are used for tissue decellularization:
“ Physical methods include snap freezing that disrupt cells by forming ice crystals,
high pressure that burst cells and agitation, that induce cell lysis and are used
most often in combination with chemical methods to facilitate penetration of
active molecules in the tissue.
Chemical methods of decellularization include a variety of reagents that can be
used to remove the cellular content of ECM. These substances range from acid
to alkaline treatments, as well as chelating agents such as EDTA, ionic or nonionic detergents and solutions of extreme osmolarity.
Enzymatic treatments such as trypsin, which specifi cally cleaves proteins and
nucleases that remove DNA and RNA are also commonly used to produce acellular scaffold. However, none of these methods can produce an ECM completely
free of cellular debris and a combination of techniques is often required to obtain
a material free of any cell remnant,” (Parenteau-Bareil et al. 2010 ).
There are several types of collagen-based biomaterials of fi sh origin: gels,
scaffolds, sponges, fi lms, membranes etc.
Collagen Gels In contrast to marine chitosan gels, which are well investigated with
respect to tissue engineering, fi sh collagen gels possess some limiting factors. For
example, the low denaturation temperature (Td) of most fi sh collagens with the
exception of shark collagen (Nomura et al. 2000a , b ), renders these structural
8 Marine Collagens