333
covered with an SC fi lm with a nanofi brous structure (fi bril diameter, about 70 nm).
On immersion in water, the fi lm is converted to a gel with slight swelling. There was
no rupture of the SC cover after mounting on a balloon catheter or after expansion.
Preliminary implantation was conducted by placing the balloon- expandable covered
stents in the common carotid arteries of beagles. One month after implantation, angiography showed that all stented arteries were patent with no signifi cant neointimal
thickening. The authors suggested that SC is potentially useful as a cover material of
endovascular stents to enhance patency,” (Nagai et al. 2009 ).
Collagen Membranes Fish collagen membranes have also been designed as well
as patented (see for review Andre et al. 2000 ). A bioresorbable collagen barrier
membrane (Periocol
®
) of fi sh origin has been developed for guided tissue regeneration applications in human periodontal intrabony and furcation defects (Singh et al.
2011 ). Periocol
® collagen membrane have been used as a sustained release chlorhexidine chip in chronic periodontitis patients and reported to resorb after 30 days
(Divya and Nandakumar 2006 ). Recently, high mechanical stable collagen fi bril
membranes (CFMs) of type I atelocollagen extracted from tilapia scales were
designed using a lateral face evaporation method, (see for details Xu et al. 2011 ).
These membranes showed following features:
“The density and thickness of the CFM obtained were 0.51 ± 0.04 mg/cm
3 and
50 ± 5 μm. The collagen fi brils in the CFM had a similar periodic stripped pattern of
67 nm with native collagen fi brils. The CFM was crosslinked in gaseous glutaraldehyde for different duration in order to increase the mechanical property. The crosslinking degrees of the CFMs analyzed by free amino groups gradually increased to
70.3 % against the exposure duration until 6 hours, and reached a plateau. The
denaturation temperatures of the CFMs with the crosslinking degrees at 20.4 % to
43 % were linearly increased from 49 °C to 75 °C. The tensile strength of the CFMs
was slightly improved until the crosslinking degree at 33.3 %, at which point the
tensile strength rapidly increased to be 68 MPa. It was suggested that a percolation
phenomenon took place in the CFMs by crosslinking of collagen fi brils with polymerized GA molecules,” ( Xu et al. 2011 ).
Collagen Composites Fish collagen composites with chitosan are discussed
above. However, Shen et al. ( 2008 ) reported about manufacture of DNA and salmon
collagen (SC) composite materials for wound dressing. More detailed information
is as follow:
“the sDNA/SC composites were prepared by incubating a mixture of an acidic
SC solution, an sDNA solution, and a collagen fi brillogenesis inducing buffer (pH
6.8) containing a crosslinking agent (water-soluble carbodiimide) for gelation. A
subsequent ventilation-drying process gave sDNA/SC fi lms. The sDNA/SC fi lms
with various doses of sDNA (sDNA/SC weight ratios of 1:5, 1:10, and 1:20) were
used for in vitro cell cultures to evaluate their growth potentials of normal human
dermal fi broblasts (NHDF) and normal human epidermal keratinocytes (NHEK). It
was found that NHDF proliferation was increased by sDNA conjugation, whereas
NHEK proliferation was dose-dependently inhibited. In light of the in vitro results,
8.2 Fish Collagen as a Biomaterial
covered with an SC fi lm with a nanofi brous structure (fi bril diameter, about 70 nm).
On immersion in water, the fi lm is converted to a gel with slight swelling. There was
no rupture of the SC cover after mounting on a balloon catheter or after expansion.
Preliminary implantation was conducted by placing the balloon- expandable covered
stents in the common carotid arteries of beagles. One month after implantation, angiography showed that all stented arteries were patent with no signifi cant neointimal
thickening. The authors suggested that SC is potentially useful as a cover material of
endovascular stents to enhance patency,” (Nagai et al. 2009 ).
Collagen Membranes Fish collagen membranes have also been designed as well
as patented (see for review Andre et al. 2000 ). A bioresorbable collagen barrier
membrane (Periocol
®
) of fi sh origin has been developed for guided tissue regeneration applications in human periodontal intrabony and furcation defects (Singh et al.
2011 ). Periocol
® collagen membrane have been used as a sustained release chlorhexidine chip in chronic periodontitis patients and reported to resorb after 30 days
(Divya and Nandakumar 2006 ). Recently, high mechanical stable collagen fi bril
membranes (CFMs) of type I atelocollagen extracted from tilapia scales were
designed using a lateral face evaporation method, (see for details Xu et al. 2011 ).
These membranes showed following features:
“The density and thickness of the CFM obtained were 0.51 ± 0.04 mg/cm
3 and
50 ± 5 μm. The collagen fi brils in the CFM had a similar periodic stripped pattern of
67 nm with native collagen fi brils. The CFM was crosslinked in gaseous glutaraldehyde for different duration in order to increase the mechanical property. The crosslinking degrees of the CFMs analyzed by free amino groups gradually increased to
70.3 % against the exposure duration until 6 hours, and reached a plateau. The
denaturation temperatures of the CFMs with the crosslinking degrees at 20.4 % to
43 % were linearly increased from 49 °C to 75 °C. The tensile strength of the CFMs
was slightly improved until the crosslinking degree at 33.3 %, at which point the
tensile strength rapidly increased to be 68 MPa. It was suggested that a percolation
phenomenon took place in the CFMs by crosslinking of collagen fi brils with polymerized GA molecules,” ( Xu et al. 2011 ).
Collagen Composites Fish collagen composites with chitosan are discussed
above. However, Shen et al. ( 2008 ) reported about manufacture of DNA and salmon
collagen (SC) composite materials for wound dressing. More detailed information
is as follow:
“the sDNA/SC composites were prepared by incubating a mixture of an acidic
SC solution, an sDNA solution, and a collagen fi brillogenesis inducing buffer (pH
6.8) containing a crosslinking agent (water-soluble carbodiimide) for gelation. A
subsequent ventilation-drying process gave sDNA/SC fi lms. The sDNA/SC fi lms
with various doses of sDNA (sDNA/SC weight ratios of 1:5, 1:10, and 1:20) were
used for in vitro cell cultures to evaluate their growth potentials of normal human
dermal fi broblasts (NHDF) and normal human epidermal keratinocytes (NHEK). It
was found that NHDF proliferation was increased by sDNA conjugation, whereas
NHEK proliferation was dose-dependently inhibited. In light of the in vitro results,
8.2 Fish Collagen as a Biomaterial