82
– “histochemical analysis revealed a temperature-dependent increase over time
in calcium phosphate incorporation into the extracellular matrix (ECM) of
adult cartilage;
– Ultrastructural analysis revealed the presence of ECM dense crystalline bodies
(40 nm average);
– electron-dense particles (15–20 nm) found in close association with the ECM
fi brils in some regions of mineralized cartilage;
– larval cartilage incorporated much less calcium, less uniformly over time than
did adult cartilage,” (Langille and Hall 1993 ).
Thus, experimental data confi rmed that adult lamprey cartilage mineralize under
appropriate conditions in vitro . Correspondingly, Langille and Hall ( 1993 ) hypothesized that “petromyzonids, or their direct agnathan ancestors, may have possessed
mineralized skeletons and that this ability is ‘repressed’ in extant lampreys owing
primarily to the environment they inhabit”.
One of the aims of the fi sh cartilage related tissue engineering is determined by
the screening of novel sources of bioactive substances (e.g. chondroitin sulphate) as
well as anticancer factors by in vitro culture of cartilage cells from cartilaginous
fi shes. Some experiments were very successful. For example, Shakibaei and De
Souza ( 1997 ) reported that cultivation of chondrocytes in mass culture yielded a
pure chondrocyte population. Also, new fi sh species like skate ( Raja porasa ) were
used to initiate primary cultures of cartilage cells (Fan et al. 2003 ). Interestingly,
this was the fi rst attempt to establish an in vitro culture system for cartilage cells of
skates. It was reported that the “induced cartilage cells cultured formed a confl uent
monolayer at day 7” (Fan et al. 2003 ).
2.1.3 Shark Cartilage: Medical Aspect
The discussion of the use of shark cartilage as a source of anticancer agents started
more than 30 years ago (Langer et al. 1976 ; Lee and Langer 1983 ). Interest in the
cartilage application grew because of “its avascular state coupled with the misconception that sharks do not get cancer” (Patra and Sandell 2012 ; see for review Lane
and Comac 1996 ). Although crude extracts of shark cartilage are ineffective, some
purifi ed components may work as cancer retardants (Ostrander et al. 2004 ). From
biochemical point of view, cartilage-derived inhibitor of neovascularization was
accepted to be related to enzymes of the metalloproteinases family (Moses et al.
1990 , 1992 ).
In the current literature, we can fi nd very polar opinions concerning anticancer
activity of numerous shark-cartilage-derived products. “The discovery of cancer in
sharks and the lack of promising results from the most recent clinical trial with
2 Cartilage of Marine Vertebrates
– “histochemical analysis revealed a temperature-dependent increase over time
in calcium phosphate incorporation into the extracellular matrix (ECM) of
adult cartilage;
– Ultrastructural analysis revealed the presence of ECM dense crystalline bodies
(40 nm average);
– electron-dense particles (15–20 nm) found in close association with the ECM
fi brils in some regions of mineralized cartilage;
– larval cartilage incorporated much less calcium, less uniformly over time than
did adult cartilage,” (Langille and Hall 1993 ).
Thus, experimental data confi rmed that adult lamprey cartilage mineralize under
appropriate conditions in vitro . Correspondingly, Langille and Hall ( 1993 ) hypothesized that “petromyzonids, or their direct agnathan ancestors, may have possessed
mineralized skeletons and that this ability is ‘repressed’ in extant lampreys owing
primarily to the environment they inhabit”.
One of the aims of the fi sh cartilage related tissue engineering is determined by
the screening of novel sources of bioactive substances (e.g. chondroitin sulphate) as
well as anticancer factors by in vitro culture of cartilage cells from cartilaginous
fi shes. Some experiments were very successful. For example, Shakibaei and De
Souza ( 1997 ) reported that cultivation of chondrocytes in mass culture yielded a
pure chondrocyte population. Also, new fi sh species like skate ( Raja porasa ) were
used to initiate primary cultures of cartilage cells (Fan et al. 2003 ). Interestingly,
this was the fi rst attempt to establish an in vitro culture system for cartilage cells of
skates. It was reported that the “induced cartilage cells cultured formed a confl uent
monolayer at day 7” (Fan et al. 2003 ).
2.1.3 Shark Cartilage: Medical Aspect
The discussion of the use of shark cartilage as a source of anticancer agents started
more than 30 years ago (Langer et al. 1976 ; Lee and Langer 1983 ). Interest in the
cartilage application grew because of “its avascular state coupled with the misconception that sharks do not get cancer” (Patra and Sandell 2012 ; see for review Lane
and Comac 1996 ). Although crude extracts of shark cartilage are ineffective, some
purifi ed components may work as cancer retardants (Ostrander et al. 2004 ). From
biochemical point of view, cartilage-derived inhibitor of neovascularization was
accepted to be related to enzymes of the metalloproteinases family (Moses et al.
1990 , 1992 ).
In the current literature, we can fi nd very polar opinions concerning anticancer
activity of numerous shark-cartilage-derived products. “The discovery of cancer in
sharks and the lack of promising results from the most recent clinical trial with
2 Cartilage of Marine Vertebrates