Echinoderm skeletal elements

Echinoderm skeletons are constructed from a unique, intricately shaped, 3D, single crystalline meshwork with a topological structure in which every internal pore and channel is in direct contact with all others (periodic minimal surface). This property is likely to facilitate mass transfer and tissue developmeut (Aizenberg and Hendler, 2004). 

Hydrothermal or similar conversion of calcium carbonate to calcium phosphate processing of echinoderm structures as with other mineralized skeletons such as corals, transforms the chemical and mechanical properties with equivalence to human bone (Hu et al., 2001 Vago, 2008). 

Functional natural structures optimized to their environment are produced by self-assembly. This gives us the opportunity to produce highly efficient structures that can minimize energy use, with intricate shapes and architectures that are tailored to their functions and do not break down. 

The beginning of the coral life cycle starts with the polyps, which absorb the calcium ions and carbonic acid present in the seawater to produce the calcium carbonate in the form of aragonite crystals. The remaining composition consists of trace 

The organic composition has an important part to play in coral biocompatibility. The abundance, conformation, and composition of the organic manices are responsible for successful biological integration of natural coral with human host (Green et al., 2013). 

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In search of scaffolding materials, we have so far identified candidate biomatrices in nature, with varied chemical homologies and structural analogies to human extracellular matrices and whole tissues. They include nacre marine shell, marine sponge skeletons, echinoderm skeletal elements, and coral skeletons. The utility of selected species of these marine animals has been applied to the regeneration of human bone and cartilage. However, the full utility in these tissues and other tissues has yet to be harnessed and exploited. 

Sea urchin larvae are about a hundred micrometers in diameter. They have an internal skeleton that supports the soft tissues. The skeleton is composed of one or several pairs of intricately shaped spicules, the morphologies of which vary among different species. The spicule is composed of two different minerals, amorphous calcium carbonate and calcite [66]. The mineral phases in the adult skeleton are thought to be similar to those in the larval skeleton [67]. In fact almost the whole echinoderm phylum appears to use this type of material for constructing a large variety of skeletal elements. 

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