Biocompatibility of echinoderm skeleton with mammalian cells in vitro: preliminary evidence

Biomaterials and Bioactive Natural Products from Marine Invertebrates: From Basic Research to Innovative Applications

Aquatic invertebrates are a major source of biomaterials and bioactive natural products that can find applications as pharmaceutics, nutraceutics, cosmetics, antibiotics, antifouling products and biomaterials. Symbiotic microorganisms are often the real producers of many secondary metabolites initially isolated from marine invertebrates; however, a certain number of them are actually synthesized by the macro-organisms. In this review, we analysed the literature of the years 2010–2019 on natural products (bioactive molecules and biomaterials) from the main phyla of marine invertebrates explored so far, including sponges, cnidarians, molluscs, echinoderms and ascidians, and present relevant examples of natural products of interest to public and private stakeholders. We also describe omics tools that have been more relevant in identifying and understanding mechanisms and processes underlying the biosynthesis of secondary metabolites in marine invertebrates. Since there is increasing attention on finding new solutions for a sustainable large-scale supply of bioactive compounds, we propose that a possible improvement in the biodiscovery pipeline might also come from the study and utilization of aquatic invertebrate stem cells.

Biomaterials in Periodontal Regenerative Surgery: Effects of Cryopreserved Bone, Commercially Available Coral, Demineralized Freeze-dried Dentin, and Cementum on Periodontal Ligament Fibroblasts and Osteoblasts

The ultimate goal of periodontal therapy is to achieve successful periodontal regeneration. The effects of different biomaterials, allogenic and alloplastic, used in periodontal surgeries to achieve regeneration have been studied in vitro on periodontal ligament (PDL) cells and MC3T3-E1 cells. The materials tested included cryopreserved bone allograft (CBA), coralline hydroxyapatite (CH), demineralized freeze-dried dentin (DFDD), and cementum. CBA and CH revealed an increase in initial PDL cell attachment, whereas CH resulted in an increase in long-term PDL cell attachment. Mineral-like nodule formation was observed significantly higher in DFDD compared to other materials tested for osteoblasts. Based on the results of this in vitro study, we conclude that the materials used are all biocompatible with human PDL cells and osteoblasts, which have pivotal importance in periodontal regeneration.

Simple method for preparation of nanostructurally organized spines of sand dollar Scaphechinus mirabilis (Agassiz, 1863)

Unique skeletal formations of marine invertebrates, including representatives of Echinodermata, have the unique potential to serve as templates for bio-inspired materials chemistry, biomimetics, and materials science. The sand dollar Scaphechinus mirabilis (Agassiz, 1983) is widely distributed in the northwest of the Pacific Ocean from southern Japan to the Aleutian Islands. This animal is the main source of naphtochinone-based substances. These compounds have recently drawn medical attention for their use as cardiological and ophthalmological drugs. Unfortunately, after extraction of the naphtochinones, the residual skeletons and spines of the sand dollars were usually discarded. Here, we report the first method for the preparation of nanostructurally organized spines of S. mirabilis, using a simple enzymatic and hydrogen peroxide-based treatment. Application of this method opens the way for development of non-wasteful environmentally clean technology of sand dollars as well-known industrial marine invertebrates.

Comparison of coral resorption and bone apposition with two natural corals of different porosities

Previous studies showed that natural coral implanted into bone tissue was gradually resorbed and progressively replaced by newly formed bone. The objectives of this study were to compare the fate of two Madreporian corals, Porites and Acropora, after implantation during 1 and 2 months into sheep and pig long bones. These materials are identical in composition (CaCo3) but differ in volume (49 +/- 2%, 12 +/- 4%, respectively) and mean size (250 vs. 500 microns) of porosities. The non-decalcified histological slices were observed under light microscopy. Implant resorption and new bone formation were quantified through an automatic image analysis system. Quantitative results showed that the larger the porosity volume, the greater was the coral resorption as well as the new bone apposition. Large differences were found between the two animal species. Histological findings were identical to those previously reported: implants were resorbed and progressively replaced by newly formed bone. Coral was found to be an osteoconductive biomaterial which acted as a scaffold for a direct osteoblastic apposition and consequently could be an interesting alternative to bone auto-, allo-, or xenografts.