Marine Skeletons: Towards Hard Tissue Repair and Regeneration

Abstract

Musculoskeletal disorders in the elderly have significantly increased due to the increase in an ageing population. The treatment of these diseases necessitates surgical procedures, including total joint replacements such as hip and knee joints. Over the years a number of treatment options have been specifically established which are either permanent or use temporary natural materials such as marine skeletons that possess unique architectural structure and chemical composition for the repair and regeneration of bone tissue. This review paper will give an overview of presently used materials and marine structures for hard tissue repair and regeneration, drugs of marine origin and other marine products which show potential for musculoskeletal treatment.

Current Stage of Marine Ceramic Grafts for 3D Bone Tissue Regeneration

“…The ocean provides bioceramics with interconnected porosity in a hierarchical structure similar to those of trabecular human bone, making them suitable materials as bone grafts with osteoconductive properties [61]. One example is the exoskeleton of several coral species, mainly composed of the crystalline ceramic structure aragonite (calcium carbonate).…”

“…These bioceramics are subjected to thermal treatments to avoid immunogenic responses with only tiny quantities of intra-crystalline proteins remaining. However, they possess inherent weakness in compression and the absorption of calcium carbonate is too quick, limiting the use of these grafts [61,62].…”

“…Apart from corals, other traditionally investigated marine bioceramic sources are nacre, seashells (foraminifera, bivalve mollusks as oyster and mussels), sponge skeletons, diatom frustules, sea urchin spines, cuttlefish bone [61], other fish bones such as tuna [75], and shark teeth [76,77]. When obtained as powders, these ceramics showed rod-like shape particles with submicron average size as shown in Figure 1A and excellent “in vitro” biocompatibility independently of the fish source (Figure 1B) [75].…”

“…Their re-use as bone grafts contributes to sustainability, by taking advantage of this waste and re-valorizing it into products with a higher added value. Again, calcium carbonate is the composition that mainly predominates in their structure, as is the case for nacre, oyster and mussel shells, calcareous sponges’ skeleton, sea urchin spines, and cuttlefish bone [61,78]. Others are based on silicon compounds as certain sponge skeletons and diatom frustules [79].…”

“…This material would, therefore, solve the still existing demands for bone fillers suitable in applications that require load support, being also osteoinductive. According to Zhang et al [84], nacre presents a great potential in the field of bone substitutes given its remarkable mechanical properties, with a Young’s modulus of 70 GPa (dry) or 60 GPa (wet) equivalent to steel [61]. The absence of nacre commercial products available for clinical use could be explained by the existence of regulatory aspects or purely commercial barriers (such as profitability) that hinder its entrance in the bone grafts market.…”