Evolving marine biomimetics for regenerative dentistry

Hydrothermally treated coral scaffold promotes proliferation of mesenchymal stem cells and enhances segmental bone defect healing

Introduction: Synthetic hydroxyapatite (HAp) scaffolds have shown promising therapeutic outcomes in both animals and patients. In this study, we aim to evaluate the chemical and physical phenotype, biocompatibility, and bone repair effects of hydrothermally treated coral with natural coral and synthetic HAp. Methods: The phase composition, surface pattern, 3D structures, and porosity of the scaffolds were characterized, and cell viability, proliferation, and osteogenic differentiation of mesenchymal stem cells (MSCs) after seeding onto the scaffold were determined. The scaffolds were implanted into rats to assess their bone repair effects using micro-CT analysis, mechanical testing, and histological staining. Results: The results showed that the phase composition, porous structure, and porosity of hydrothermally treated coral were comparable to pure HAp scaffold. While only the natural coral happens to be dominantly calcium carbonate. Higher cell proliferation and osteogenic differentiation potential were observed in the hydrothermally treated coral scaffold compared to natural coral and pure HAp. Histological results also showed increased new bone formation in the hydrothermally treated coral group. Discussion: Overall, our study suggests that hydrothermal modification enhances the cytocompatibility and therapeutic capacity of coral without altering its physical properties, showing superior effectiveness in bone repair to synthetic HAp.

A forgotten element of the blue economy: marine biomimetics and inspiration from the deep sea

The morphology, physiology, and behavior of marine organisms have been a valuable source of inspiration for solving conceptual and design problems. Here, we introduce this rich and rapidly expanding field of marine biomimetics, and identify it as a poorly articulated and often overlooked element of the ocean economy associated with substantial monetary benefits. We showcase innovations across seven broad categories of marine biomimetic design (adhesion, antifouling, armor, buoyancy, movement, sensory, stealth), and use this framing as context for a closer consideration of the increasingly frequent focus on deep-sea life as an inspiration for biomimetic design. We contend that marine biomimetics is not only a "forgotten" sector of the ocean economy, but has the potential to drive appreciation of nonmonetary values, conservation, and stewardship, making it well-aligned with notions of a sustainable blue economy. We note, however, that the highest ambitions for a blue economy are that it not only drives sustainability, but also greater equity and inclusivity, and conclude by articulating challenges and considerations for bringing marine biomimetics onto this trajectory.

Pinctada Maxima Pearl Shells as a Promising Bone Graft Material in the World of Dentistry

BACKGROUND: Pinctada maxima pearl shell contains inorganic and organic materials that have a bone-like basic structure that facilitates bone remodeling. AIM: This study aimed to describe the effectiveness of Pinctada maxima pearl shells as bone graft material in the world of dentistry using an animal model. METHODS: Research uses Pinctada maxima pearl shell that was processed into hydroxyapatite Pinctada maxima (HPM) powder. Chemical and surface characteristics of HPM were performed with X-ray fluorescence (XRF), Fourier transform infra-red (FTIR), and X-ray diffraction (XRD), respectively. Thirty male guinea pigs were randomly assigned into three groups: Negative control (NC), positive control, and HPM. After 14–21 days of observation, guinea pigs were sacrificed. Bone formation was seen through immunohistochemical examination of osteoprotegerin (OPG) and bone morphogenetic protein (BMP2) expression. Data were analyzed through Shapiro wills and analysis of variance with a significance level of 5%. RESULTS: There was a high expression of OPG and BMP2 on days 14–21 in the HPM group when compared to the NC group with a significance level of 5%. CONCLUSION: HPM powder can be used as a promising bone graft material in the world of dentistry.

Biomimetic Aspects of Oral and Dentofacial Regeneration

Biomimetic materials for hard and soft tissues have advanced in the fields of tissue engineering and regenerative medicine in dentistry. To examine these recent advances, we searched Medline (OVID) with the key terms “biomimetics”, “biomaterials”, and “biomimicry” combined with MeSH terms for “dentistry” and limited the date of publication between 2010–2020. Over 500 articles were obtained under clinical trials, randomized clinical trials, metanalysis, and systematic reviews developed in the past 10 years in three major areas of dentistry: restorative, orofacial surgery, and periodontics. Clinical studies and systematic reviews along with hand-searched preclinical studies as potential therapies have been included. They support the proof-of-concept that novel treatments are in the pipeline towards ground-breaking clinical therapies for orofacial bone regeneration, tooth regeneration, repair of the oral mucosa, periodontal tissue engineering, and dental implants. Biomimicry enhances the clinical outcomes and calls for an interdisciplinary approach integrating medicine, bioengineering, biotechnology, and computational sciences to advance the current research to clinics. We conclude that dentistry has come a long way apropos of regenerative medicine; still, there are vast avenues to endeavour, seeking inspiration from other facets in biomedical research.

3D Chitin Scaffolds of Marine Demosponge Origin for Biomimetic Mollusk Hemolymph-Associated Biomineralization Ex-Vivo

Structure-based tissue engineering requires large-scale 3D cell/tissue manufacture technologies, to produce biologically active scaffolds. Special attention is currently paid to naturally pre-designed scaffolds found in skeletons of marine sponges, which represent a renewable resource of biomaterials. Here, an innovative approach to the production of mineralized scaffolds of natural origin is proposed. For the first time, a method to obtain calcium carbonate deposition ex vivo, using living mollusks hemolymph and a marine-sponge-derived template, is specifically described. For this purpose, the marine sponge Aplysin aarcheri and the terrestrial snail Cornu aspersum were selected as appropriate 3D chitinous scaffold and as hemolymph donor, respectively. The formation of calcium-based phase on the surface of chitinous matrix after its immersion into hemolymph was confirmed by Alizarin Red staining. A direct role of mollusks hemocytes is proposed in the creation of fine-tuned microenvironment necessary for calcification ex vivo. The X-ray diffraction pattern of the sample showed a high CaCO3 amorphous content. Raman spectroscopy evidenced also a crystalline component, with spectra corresponding to biogenic calcite. This study resulted in the development of a new biomimetic product based on ex vivo synthetized ACC and calcite tightly bound to the surface of 3D sponge chitin structure.

Key Insights, Tools, and Future Prospects on Oyster Shell End-of-Life: A Critical Analysis of Sustainable Solutions

Oyster farming represents one of the most developed aquaculture activities, producing delicacies unfortunately related to a direct accumulation of waste shells. Facing what is becoming an environmental issue, chemists are currently developing solutions to add value to this wild source of raw material in line with the principles of sustainable chemistry. An argumentative overview of this question is proposed here with a focus on recent data. Starting with a presentation of the environmental impact of oyster farming, existing and promising applications are then classified according to the type of raw materials derived from the oyster shell, namely the natural oyster shell (NOS), the calcined natural oyster shell (CNOS), and biomolecules of the organic matrix extracted from the oyster shell. Their relevance is discussed in regard to their scalability, originality, and sustainability. This review constitutes the first critical compilation on oyster shell applications, with the aim to provide essential elements to better comprehend the recycling of waste oyster shells.

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

Bioceramic scaffolds are crucial in tissue engineering for bone regeneration. They usually provide hierarchical porosity, bioactivity, and mechanical support supplying osteoconductive properties and allowing for 3D cell culture. In the case of age-related diseases such as osteoarthritis and osteoporosis, or other bone alterations as alveolar bone resorption or spinal fractures, functional tissue recovery usually requires the use of grafts. These bone grafts or bone void fillers are usually based on porous calcium phosphate grains which, once disposed into the bone defect, act as scaffolds by incorporating, to their own porosity, the intergranular one. Despite their routine use in traumatology and dental applications, specific graft requirements such as osteoinductivity or balanced dissolution rate are still not completely fulfilled. Marine origin bioceramics research opens the possibility to find new sources of bone grafts given the wide diversity of marine materials still largely unexplored. The interest in this field has also been urged by the limitations of synthetic or mammalian-derived grafts already in use and broadly investigated. The present review covers the current stage of major marine origin bioceramic grafts for bone tissue regeneration and their promising properties. Both products already available on the market and those in preclinical phases are included. To understand their clear contribution to the field, the main clinical requirements and the current available biological-derived ceramic grafts with their advantages and limitations have been collected.

Synthetic and Marine-Derived Porous Scaffolds for Bone Tissue Engineering

Bone is a vascularized and connective tissue. The cortical bone is the main part responsible for the support and protection of the remaining systems and organs of the body. The trabecular spongy bone serves as the storage of ions and bone marrow. As a dynamic tissue, bone is in a constant remodelling process to adapt to the mechanical demands and to repair small lesions that may occur. Nevertheless, due to the increased incidence of bone disorders, the need for bone grafts has been growing over the past decades and the development of an ideal bone graft with optimal properties remains a clinical challenge. This review addresses the bone properties (morphology, composition, and their repair and regeneration capacity) and puts the focus on the potential strategies for developing bone repair and regeneration materials. It describes the requirements for designing a suitable scaffold material, types of materials (polymers, ceramics, and composites), and techniques to obtain the porous structures (additive manufacturing techniques like robocasting or derived from marine skeletons) for bone tissue engineering applications. Overall, the main objective of this review is to gather the knowledge on the materials and methods used for the production of scaffolds for bone tissue engineering and to highlight the potential of natural porous structures such as marine skeletons as promising alternative bone graft substitute materials without any further mineralogical changes, or after partial or total transformation into calcium phosphate.

Marine Skeletons: Towards Hard Tissue Repair and Regeneration

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.

Interfacial Mineral Fusion and Tubule Entanglement as a Means to Harden a Bone Augmentation Material

A new bone augmenting material is reported, which is formed from calcium-loaded hydrogel-based spheres. On immersion of these spheres in a physiological medium, they become surrounded with a sheath of precipitate, which ruptures due to a build-up in osmotic pressure. This results in the formation of mineral tubes that protrude from the sphere surface. When brought into close contact with one another, these spheres become fused through the entanglement and subsequent interstitial mineralization of the mineral tubules. The tubular calcium phosphate induces the expression of osteogenic genes (runt-related transcription factor 2 (RUNX2), transcription factor SP7 (SP7), collagen type 1 alpha 1 (COL1A1), and bone gamma-carboxyglutamic acid-containing protein (BGLAP)) and promotes the formation of mineral nodules in preosteoblast cultures comparable to an apatitic calcium phosphate phase. Furthermore, alkaline phosphatase (ALP) is significantly upregulated in the presence of tubular materials after 10 d in culture compared with control groups (p < 0.001) and sintered apatite (p < 0.05). This is the first report of a bioceramic material that is formed in its entirety in situ and is therefore likely to provide a better proxy for biological mineral than other existing synthetic alternatives to bone grafts.

The importance of applying Standardised Integrative Taxonomy when describing marine benthic organisms and collecting ecological data

The decline of morphologically based taxonomy is mainly linked to increasing species redundancy, which probably contributed to a worldwide disinterest in taxonomy, and to a reduction of funding for systematic biology and for expertise training. The present trend in the study of biodiversity is integrated taxonomy, which merges morphological and molecular approaches. At the same time, in many cases new molecular techniques have eclipsed the morphological approach. The application of Standardised Integrative Taxonomy, i.e. a rigorous, common method of description based on the integration between ecological and morphological characteristics, may increase the precision, accessibility, exploitability and longevity of the collected data, and favour the renaissance of taxonomy by new investments in biodiversity exploration.

Scientific basis of dentistry

Technological and scientific innovations have increased exponentially over the past years in the dentistry profession. In this article, these developments are evaluated both in terms of clinical practice and their place in the educational program. The effect of the biologic and digital revolutions on dental education and daily clinical practice are also reviewed. Biomimetics, personalized dental medicine regenerative dentistry, nanotechnology, high-end simulations providing virtual reality, genomic information, and stem cell studies will gain more importance in the coming years, moving dentistry to a different dimension.

Immobilization of Titanium(IV) Oxide onto 3D Spongin Scaffolds of Marine Sponge Origin According to Extreme Biomimetics Principles for Removal of C.I. Basic Blue 9

The aim of extreme biomimetics is to design a bridge between extreme biomineralization and bioinspired materials chemistry, where the basic principle is to exploit chemically and thermally stable, renewable biopolymers for the development of the next generation of biologically inspired advanced and functional composite materials. This study reports for the first time the use of proteinaceous spongin-based scaffolds isolated from marine demosponge Hippospongia communis as a three-dimensional (3D) template for the hydrothermal deposition of crystalline titanium dioxide. Scanning electron microscopy (SEM) assisted with energy dispersive X-ray spectroscopy (EDS) mapping, low temperature nitrogen sorption, thermogravimetric (TG) analysis, X-ray diffraction spectroscopy (XRD), and attenuated total reflectance⁻Fourier transform infrared (ATR⁻FTIR) spectroscopy are used as characterization techniques. It was found that, after hydrothermal treatment crystalline titania in anatase form is obtained, which forms a coating around spongin microfibers through interaction with negatively charged functional groups of the structural protein as well as via hydrogen bonding. The material was tested as a potential heterogeneous photocatalyst for removal of C.I. Basic Blue 9 dye under UV irradiation. The obtained 3D composite material shows a high efficiency of dye removal through both adsorption and photocatalysis.

Recent advancements in regenerative dentistry: A review

Although human mouth benefits from remarkable mechanical properties, it is very susceptible to traumatic damages, exposure to microbial attacks, and congenital maladies. Since the human dentition plays a crucial role in mastication, phonation and esthetics, finding promising and more efficient strategies to reestablish its functionality in the event of disruption has been important. Dating back to antiquity, conventional dentistry has been offering evacuation, restoration, and replacement of the diseased dental tissue. However, due to the limited ability and short lifespan of traditional restorative solutions, scientists have taken advantage of current advancements in medicine to create better solutions for the oral health field and have coined it "regenerative dentistry." This new field takes advantage of the recent innovations in stem cell research, cellular and molecular biology, tissue engineering, and materials science etc. In this review, the recently known resources and approaches used for regeneration of dental and oral tissues were evaluated using the databases of Scopus and Web of Science. Scientists have used a wide range of biomaterials and scaffolds (artificial and natural), genes (with viral and non-viral vectors), stem cells (isolated from deciduous teeth, dental pulp, periodontal ligament, adipose tissue, salivary glands, and dental follicle) and growth factors (used for stimulating cell differentiation) in order to apply tissue engineering approaches to dentistry. Although they have been successful in preclinical and clinical partial regeneration of dental tissues, whole-tooth engineering still seems to be far-fetched, unless certain shortcomings are addressed.

Marine Structural Biomaterials in Medical Biomimicry

Marine biomaterials display properties, behaviors, and functions that have not been artificially matched in relation to their hierarchical construction, crack-stopping properties, growth adaptation, and energy efficiency. The discovery and understanding of such features that are characteristic of natural biomaterials can be used to manufacture more energy-efficient and lightweight materials. However, a more detailed understanding of the design of natural biomaterials with good performance and the mechanism of their design is required. Far-reaching biomolecular characterization of biomaterials and biostructures from the ocean world is possible with sophisticated analytical methods, such as whole-genome RNA-seq, and de novo transcriptome sequencing and mass spectrophotometry-based sequencing. In combination with detailed material characterization, the elements in newly discovered biomaterials and their properties can be reconstituted into biomimetic or bio-inspired materials. A major aim of harnessing marine biomaterials is their translation into biomimetic counterparts. To achieve full translation, the genome, proteome, and hierarchical material characteristics, and their profiles in space and time, have to be associated to allow for smooth biomimetic translation. In this article, we highlight the novel science of marine biomimicry from a materials perspective. We focus on areas of material design and fabrication that have excelled in marine biological models, such as embedded interfaces, chiral organization, and the use of specialized composite material-on-material designs. Our emphasis is primarily on key materials with high value in healthcare in which we evaluate their future prospects. Marine biomaterials are among the most exquisite and powerful aspects in materials science today.

Adsorption of C.I. Natural Red 4 onto Spongin Skeleton of Marine Demosponge

C.I. Natural Red 4 dye, also known as carmine or cochineal, was adsorbed onto the surface of spongin-based fibrous skeleton of Hippospongia communis marine demosponge for the first time. The influence of the initial concentration of dye, the contact time, and the pH of the solution on the adsorption process was investigated. The results presented here confirm the effectiveness of the proposed method for developing a novel dye/biopolymer hybrid material. The kinetics of the adsorption of carmine onto a marine sponge were also determined. The experimental data correspond directly to a pseudo-second-order model for adsorption kinetics (r² = 0.979–0.999). The hybrid product was subjected to various types of analysis (FT-IR, Raman, ¹³C CP/MAS NMR, XPS) to investigate the nature of the interactions between the spongin (adsorbent) and the dye (the adsorbate). The dominant interactions between the dye and spongin were found to be hydrogen bonds and electrostatic effects. Combining the dye with a spongin support resulted with a novel hybrid material that is potentially attractive for bioactive applications and drug delivery systems.

Diatoms: a biotemplating approach to fabricating drug delivery reservoirs

Biotemplating is a rapidly expanding subfield that utilizes nature-inspired systems and structures to create novel functional materials, and it is through these methods that the limitations of current engineering practices may be advanced. The diatom is an exceptional template for drug delivery applications, owing largely to its highly-ordered pores, large surface area, species-specific architecture, and flexibility for surface modifications. Diatoms have been studied in a wide range of biomedical applications and their potential as the next frontier of drug delivery has yet to be fully exploited. In this editorial, the authors aim to review the use of diatoms in the delivery of poorly water-soluble drugs as reported in the literature, discuss the progress and advancements that have been made thus far, identify the shortcomings and limitations in the field, and, lastly, present their expert opinion and convey the future outlook on biotemplating approaches for drug delivery.