Bioceramic Production from Sea Urchins

Abstract

Bioceramic nanopowders, currently one of the most demanding challenges for producing new biomaterials, have been tackled only when starting from chemical reagents. There are few studies aiming at producing hydroxyapatite nanopowders from naturally derived raw materials, such as nacre shells. Natural species of sea origin, such as corals and nacres, always attract special interest in biomaterials science and technology. Nacre shells are made up of pure aragonite crystallized in an organic matrix. The most common way to transform aragonite structures to hydroxyapatite is via hydrothermal transformation under very high pressure. However, such ways can be very dangerous if the equipment is worn. Ultrasonic and hotplate methods are apparently very safe. This work proposes a new approach for developing highly bioactive fine powders of Ca-phosphates (which can be used afterwards to build up hydroxyapatite-based bioceramic bone-scaffolds) from sea urchins via the above mentioned methods. The suspended raw powders were put on a hotplate (i.e. ultrasound). The temperature was set to 80• C for 15 min and then, equivalent (to the amount of CaCO 3 in the sea urchins) amount of H 3 PO 4 was added drop by drop into the solution. The reaction continued for 2 h. Then, to evaporate the liquid part, the mixture was put into an incubator at 100• C for 24 h and the resultant dried sediment was collected. X-ray diffraction analysis identified various calcium phosphate phases, predominantly monetite, and tricalcium phosphate as a secondary phase. The worldwide availability and the low cost of all kinds of nacre and sea urchin shells, along with their biological-natural origin are attractive features conferring to them a high potential for preparing calcium phosphate materials for uses in biomedicine. Heart urchin, used in this study, can be an ideal candidate for producing bioceramic particles.

Effect of CO2 driven ocean acidification on calcification, physiology and ovarian cells of tropical sea urchin Salmacis virgulata – A microcosm approach

“…Interplay of one form of CaCO 3 to other form reported in many animals. For instance, nacre shells purely made up of aragonite crystal and they can transform to hydroxyapatite by hydrothermal transformation in high pressure ( Agaogullari, 2012 ). Sea urchins have complex skeletal structure; though inter-relation among amorphous calcium carbonate, calcite and intra-crystalline organics is not clear; the biomineralization process in sea urchin is well documented where the transient form of hydrated ACC dehydrates to form ACC and subsequently transformed to calcite ( Wolpert and Gustafson 1961 ; Brecevic and Nielsen 1989 ; Clarkson et al., 1992 ; Beniash et al., 1997 ; Decker et al., 1987 ; Yutao Gong et al., 2012 ).…”

Novel Trends into the Development of Natural Hydroxyapatite-Based Polymeric Composites for Bone Tissue Engineering

“…Vecchio et al performed a classic hydrothermal conversion process from sea urchin spines into TCP. The obtained products exhibited good bioactivity and osteoconductivity [ 145 ]. Researchers demonstrated that rod-shaped HA crystals are favored in the attachment of proteins, especially in the binding of vitamin D, applied in BTE, due to its strong adhesion to osteoclasts and similarity with the native HA structure.…”

Response of Sea Urchin Fitness Traits to Environmental Gradients Across the Southern California Oxygen Minimum Zone

“…In addition to Mg, numerous other co-precipitated elements are differentially incorporated into biotic calcitic structures such as phosphorus (P; e.g., calcium phosphate) and strontium (Sr; e.g., strontium calcite) (Mackenzie et al, 1983). Some trace metals, such as iron (Fe) and zinc (Zn), have been found to enhance mechanical properties of biomineralized structures (e.g., iron oxides, zinc oxides), and inspire the development of anthropogenic biomaterials (Meyers et al, 2008;Agaogullari et al, 2012;Naleway et al, 2016).…”