Biomaterial structure in deep‐sea bamboo coral (Anthozoa: Gorgonacea: Isididae): perspectives for the development of bone implants and templates for tissue engineering

Abstract

Natural structural biomaterials of marine origin including mollusc shells, sponges and corals not only provide an abundant source of novel bone and cartilage replacements but also inspire investigations to develop nano-sized biomimetic composites. This study presents a characterisation of the ultrastructure of the deep-sea Bamboo coral (Anthozoa: Gorgonacea: Isididae) and the nanostructure of some interstitial surfaces with respect to biomineralization phenomena. The skeletons of the corals examined exhibit jointed axes of large bony calcareous structures alternated with smaller proteinaceous nodes of gorgonin, giving the skeletal remains of the organism a digitated appearance, like terrestrial bamboo. To test the hypothesis that bamboo coral internodes exhibit bone-like mechanical and biochemical properties, structural and biochemical analyses of these natural biomineral composites and separation of proteinaceous components was performed. Due to its high potential for colonization with both human osteoblasts and osteoclasts, the organic matrix, composed of an acidic fibrillar protein framework, proved to be a very successful model for possible applications in tissue engineering. The material properties of the calcareous internodes correlate well with the material property charts for materials used in orthopedic surgery, though denser and stronger than bone. Results of the present study also clearly indicate the quinonproteinaceous nature of the gorgonin. On the basis of the high biomimetic potential of the results obtained, the use of Isididae corals as "living bone implants" as well as their biotechnological aquacultural cultivation seems to be promising for the near future.

Carbonate “clumped” isotope signatures in aragonitic scleractinian and calcitic gorgonian deep-sea corals

“…The presence of an insoluble organic matrix in both isidid bamboo and Corallium sp. (Allemand et al, 1994;Ehrlich et al, 2006;Noé and Dullo, 2006) supports the possibility that an organic template may be directing mineral precipitation. The presence of an organic matrix is unique to gorgonian corals (has not been observed in scleractinians) and only preliminary studies have been undertaken to characterize the amino acid composition of the organic matrixes (Allemand et al, 1994;Ehrlich et al, 2006).…”

Reproducibility of trace element profiles in a specimen of the deep-water bamboo coral Keratoisis sp.

“…Calcitic internodes of bamboo corals contain a fibrillar organic matrix (Ehrlich et al, 2006) and other gorgonians are rich in organic material (e.g. Sherwood, 2002).…”

Biomimetics and Marine Materials in Drug Delivery and Tissue Engineering

“…Ehrlich et al [52] emphasized that, as a result of the unique nanoscale organization of organic tissue and mineral, biomineralization and structural studies of coral can be used to enlighten the development of new advanced functional materials. The deep-sea bamboo coral exhibits at a macrostructural level bone-like biochemical and mechanical properties.…”

“…Collagenous gorgonin proteins can be hardened and cross-linked using quinones, and the final product closely resembles human keratin. The mechanism by which gorgonin is synthesized and interacts with the process of mineralization may provide lessons for the production of a synthetic collagen-like material [52].…”