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The production of porous ceramics for biomedical applications is widely available in the Ceramics industry. In bioceramic applications, interconnected pores are pertinent to increase osteoconductivity and cell proliferation. However, an increase in pore size and the pore amount decrease the mechanical properties. For this reason, pore properties must be precisely controlled. In this study, the effect of a natural pore-forming agent, corn starch addition, and sintering conditions on mechanical properties and biocompatibility was investigated. During mixing, four different starch amounts (1, 3, 5, and 10 wt%) were added to pure beta-tricalcium phosphate (β-TCP) ceramic powders and pressed. Pressed pellets were sintered at 1000, 1100, 1200, and 1300 °C. A scanning electron microscope (SEM) is used to investigate microstructure, texture, pore size, and cell adhesion. The mechanical properties of the β-TCP ceramic parts were further characterized by measuring the density and compressive strength. Cytotoxicity tests were carried out with MTT assays. The optimum mechanical properties were obtained at 1100 °C sintered biocomposites. Although starch starts to burn around 410 °C and analytical results show no presence of starch after the sintering process, biocomposites initially containing 10% starch showed improved cell proliferation. However, a reduction of 59% in compressive strength and a 16% reduction in the density were also recorded. It was observed that 10 wt% starch addition increases cell proliferation by 10% in sintered β-TCP samples. Starch powder additions can be used to increase the cell viability of the material by facilitating the creation of pores, as a low-cost pore-forming agent for porous bone graft and non-load-bearing material in both orthopaedics and maxillofacial applications. Graphical abstract: [Figure not available: see fulltext.]

Bioceramics are a fast-growing materials group, which are widely used in orthopedics, maxillofacial, dental, and reconstructive surgeries. They are produced using raw materials either from synthetic or natural sources. As naturally originated resources, the bones of sheep and cows are used after converting to calcium phosphates. Human-originated sources in the past were obtained from human cadaver bones, however now-a-days this has been discontinued. On the other hand, the “golden standard” in the reconstruction surgery has been using patients own bones, -i.e., autogenous bones, which heal better than other alternatives. Besides natural products, synthetic materials are produced from a range of inorganic raw and natural materials based on marine sources, such as corals, and other marine-derived materials (i.e., seashells, nacre). These are used to produce bioceramics and hence implants, devices, and bone grafts. Although during the last four decades a number of excellent books and book chapters have been published, no comprehensive review has been yet reported to cover the available marine materials and to indicate the related work and corresponding references to allow for both medical and ceramic scientists to access directly and open new avenues for further research on marine structures and their applications in orthopedic, maxillofacial, and reconstructive surgery areas. Hence, this review covers the general marine structures, their locations and availability in different countries and, current research on production methods of these unique structures that are difficult to fabricate synthetically. The authors are confident that this comprehensive review will be an excellent source not only for the ceramists, but also for the medical scientists.

Biphasic macroporous Hydroxyapatite/β-Tricalcium Phosphate (HA/β-TCP) scaffolds (BCPs) are widely used for bone repair. However, the high-temperature HA and β-TCP phases exhibit limited bioactivity (low solubility of HA, restricted surface area, low ion release). Strategies were developed to coat such BCPs with biomimetic apatite to enhance bioactivity. However, this can be associated with poor adhesion, and metastable solutions may prove difficult to handle at the industrial scale. Alternative strategies are thus desirable to generate a highly bioactive surface on commercial BCPs. In this work, we developed an innovative “coating from” approach for BCP surface remodeling via hydrothermal treatment under supercritical CO2, used as a reversible pH modifier and with industrial scalability. Based on a set of complementary tools including FEG-SEM, solid state NMR and ion exchange tests, we demonstrate the remodeling of macroporous BCP surface with the occurrence of dissolution–reprecipitation phenomena involving biomimetic CaP phases. The newly precipitated compounds are identified as bone-like nanocrystalline apatite and octacalcium phosphate (OCP), both known for their high bioactivity character, favoring bone healing. We also explored the effects of key process parameters, and showed the possibility to dope the remodeled BCPs with antibacterial Cu2+ ions to convey additional functionality to the scaffolds, which was confirmed by in vitro tests. This new process could enhance the bioactivity of commercial BCP scaffolds via a simple and biocompatible approach.

The hydrozoan Millepora dichotoma (MD) is a typical Red Sea species containing a porous skeleton in the form of aragonite crystalline calcium carbonate. Due to environmental considerations, the artificial production of coralline species under controlled conditions is pertinent and underway. Artificially grown MD was used as a raw material for the production of calcium phosphate, mainly hydroxyapatite bioceramics, to be used in the drug delivery systems as a drug carrier or in the tissue engineering such as bone graft. DTA-TGA, XRD, FT-IR, Raman, and SEM analysis were carried out to analyze both unconverted and converted artificial corals. Hydrothermally converted coral fine powders were loaded with gentamicin (Gm) antibiotic, and the drug-loaded particles were analyzed by SEM. Unconverted coral was mainly aragonite, while hydrothermally treated coral was completely converted to hydroxyapatite. Hydrothermally treated coral was showing agglomerated nodules up to 1-μm size consisting of nanocrystalline hydroxyapatite platelets in the size range of less than 100 nm. The general macropore size of the coral was found to be appropriate for osteoid growth, which is 100 to 600 μm range. These artificially grown corals can be easily produced and used for bone growth and repair and other biomedical applications.

Most marine materials, by nature, contain crystals of inorganic matter with specific structures that allow the loading, release, and delivery of biomolecules that can be utilized in clinical applications. These structures can be biomimetically synthesized. Aggregates of inorganic particles generated by biomimetic microsponges may provide surfaces and structures for cell attachment, organization, and promotion of matrix synthesis. Biomimetic microsponges have been developed with tunable release profiles differing by the rate (speed over distance), velocity (rate of change in direction), and the quantity discharged over time, according to biomolecular species. Specifically, the types of proteins involved guide and regulate cells in physical contact with the microsponges, for instance, reprogramming somatic cells, the switching phenotypes, or specifying stem cell differentiation. Applications for these microsponges include gene transfection of localized cells and promotion of bone matrix synthesis by the externalized display of RGD cell adhesive peptides and the release of crystal entrapped, occluded, adsorbed and infused rhBMP-2 and plasmid. A requirement for de novo bone formation is a solid structure to enable osteocytes to lay new bone tissue. In this study, biomimetic microsponges highlight tremendous potential as osteoconductive packing material in bone repair with parallel influence on regeneration. Majorly, microsponges offer pronounced osteoinductivity, unlike many other bone particulates, by solid-state integration of active regenerative biological molecules through the prism of the biomineral crystalline structure.

© 2019, Australian Ceramic Society. Most methods for producing calcium phosphates involve synthetic calcium and phosphates sources. However, it has recently been proposed that calcium phosphate can be produced with bio-based calcium sources such as nacre, coral, and cuttlefish bones. One specific source of bio-based calcium is found in the Achatina snail shell, which becomes a waste product after flesh consumption. The present work aimed to assess the effectiveness of Achatina snail shells and to study the conversion kinetics in both acid and alkaline environment rich in phosphate ions. It was observed that in acidic conditions, the calcium released by the dissolution of the aragonite precipitates with the phosphate ions of reaction medium induces brushite formation which is rapidly converted into monetite. In alkaline conditions, calcium released from aragonite reacts with surrounding phosphates and carbonate ions and induces carbonated apatite precipitation. Regardless of the source of calcium used in the presence of phosphate, the conversion is carried out according to complex phenomena that involve topotactic transformation or dissolution-precipitation mechanisms.

Dental implants have been used as far back as 2000BC, and since then have developed into highly sophisticated solutions for tooth replacement. It is becoming increasingly important for the materials used in dental implants to exhibit and maintain favorable long-term mechanical, biological and more recently, aesthetic properties. This review aims to assess the biomaterials used in modern dental implants, introducing their properties, and concentrating on modifications to improve these biomaterials. Focus is drawn to the prominent biomaterials, titanium (Ti) and zirconia due to their prevalence in implant dentistry. Additionally, novel coatings and materials with potential use as viable improvements or alternatives are reviewed. An effective dental biomaterial should osseointegrate, maintain structural integrity, resist corrosion and infection, and not cause systemic toxicity or cytotoxicity. Current materials such as bioactive glass offer protection against biofilm formation, and when combined with a titanium–zirconium (TiZr) alloy, provide a reliable combination of properties to represent a competitive alternative. Further long-term clinical studies are needed to inform the development of next-generation materials. Significance Statement Biomaterials have become essential for modern implants. A suitable implant biomaterial integrates into the body to perform a key function, whilst minimizing negative immune response. Focusing on dentistry, the use of dental implants for tooth replacement requires a balance between bodily response, mechanical structure and performance, and aesthetics. This mini-review addresses the use of biomaterials in dental implants with significant comparisons drawn between Ti and zirconia. Attention is drawn to optimizing surface modification processes and the additional use of coatings. Alternatives and novel developments are addressed, providing potential implications of combining biomaterials to form novel composites that combine and synergize the benefits of each material.

Calcium phosphate materials can be produced using a number of wet methods that are based on hydrothermal or co-precipitation methods that might use acidic or basic chemical environments. In our previously published works, we have investigated calcium phosphates such as monetite, hydroxyapatite, and whitlockite which were successfully produced by mechano-chemical methods and/or hydrothermal treatments from a range of marine shells and corals which were obtained from the Great Barrier Reef. The aim of the current work was to analyze and compare the mechanisms of conversion of one hard coral species and one calcified algae species from the Great Barrier Reef.

© 2019 Elsevier B.V. Post-operative infection often occurs following orthopedic and dental implant placement requiring systemically administered antibiotics. However, this does not provide long-term protection. Over the last few decades, alternative methods involving slow drug delivery systems based on biodegradable poly-lactic acid and antibiotic loaded hydroxyapatite microspheres were developed to prevent post-operative infection. In this study, thermally anodised and untreated Ti6Al4V discs were coated with Poly-Lactic Acid (PLA) containing Gentamicin (Gm) antibiotic-loaded coralline Hydroxyapatite (HAp) are investigated. Following chemical characterization, mechanical properties of the coated samples were measured using nanoindentation and scratch tests to determine the elastic modulus, hardness and bonding adhesion between film and substrate. It was found that PLA biocomposite multilayered films were around 400 nm thick and the influence and effect of the substrate were clearly observed during the nanoindentation studies with heavier loads. Scratch tests of PLA coated samples conducted at ~160 nm depth showed the minimal difference in the measured friction between Gm and non Gm containing films. It is also observed that the hardness values of PLA film coated anodised samples ranged from 0.45 to 1.9 GPa (dependent on the applied loads) against untreated coated samples which ranged from 0.28 to 0.8 GPa.

Marine structure, coralline materials were converted to calcium phosphate using two different phosphate solutions. The aim was to study the conversion mechanisms under acidic and basic environment at moderate conditions of temperature. Crystal growth and morphology of converted corals were characterized by XRD and SEM respectively. The results suggested that under acidic conditions (H3PO4), dissolution and precipitation control and direct the crystal formation and morphology in which transition from plate like to rod like hydroxyapatite structure was favoured. Metastable phase such as monetite formed and transformed to HAp during reaction. During the first hour of the dissolution a monetite and hydroxyapatite mixture precipitates and then the full conversion to hydroxyapatite is observed. On the other hand, under basic conditions (NH4)2HPO4, just diffusional surface conversion of the calcium carbonate structure of coralline materials to hydroxyapatite and a very small amount of tri-calcium phosphate is observed. The mechanism can be classified as the solid-state topotactic ion-exchange reaction mechanism.

27th Symposium and Annual Meeting of the International Society for Ceramics in Medicine, 2015 -- 27 October 2015 through 29 October 2015, Bioceramics is very important application for dental and orthopedic procedures. Beside all these normal procedures traffic accidents are requiring increasing number of graft, prostheses and orthosis applications. Bioceramics can be produced from local and natural sources with various methods. Those can be produced from various bone structures through calcination (at high temperatures) or with diluted hydrochloric acid (HCl) application & freeze drying. Beside these methods calcite and aragonite structures like from sea shells and egg shells bioceramic production can be realized through mechanochemical processing via a simple hot-plate or ultrasonic equipment. A fresh water snail shell (Zebra Nerite Snail-Neritina natalensis) was prepared as bioceramic production source. The resulting hydroxyapatite (HA) powders were obtained without any impurities. At two varying temperature of 865 and 885 0C the snail shells was transformed to HA bioceramics. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential thermal analysis (TG/DTA) were evaluated. © 2016 Trans Tech Publications, Switzerland.

© 2016 Future Medicine Ltd. During the last two decades although many calcium phosphate based nanomaterials have been proposed for both drug delivery, and bone regeneration, their coating applications have been somehow slow due to the problems related to their complicated synthesis methods. In order to control the efficiency of local drug delivery of a biomaterial the critical pore sizes as well as good control of the chemical composition is pertinent. A variety of calcium phosphate based nanocoated composite drug delivery systems are currently being investigated. This review aims to give an update into the advancements of calcium phosphate nanocoatings and thin film nanolaminates. In particular recent research on PLA/hydroxyapatite composite thin films and coatings into the slow drug delivery for the possible treatment of osteomyelitis is covered.

© 2017, Australian Ceramic Society. Nanofibrous composites of the poly(ε-caprolactone) (PCL), tricalcium phosphate (TCP), and hexagonal boron nitride (h-BN) with different compositions were manufactured by using an economical and non-complicated method called electrospinning. Produced fibrous structures showed no bead formation and had a clean surface. Characterization of the composites showed that particles were successfully mixed with polymer phase. High cell activity of SaOS-2 cells on the composites was observed with SEM images. In addition, fibrous scaffolds are biocompatible with human bone tissue and are highly degradable.

© 2018 Elsevier Ltd. All rights reserved. Ceramic matrix composites (CMCs) are replacing other materials in applications where the higher costs are offset by improvements in performance. Due to their lack of toughness they are prone to catastrophic failure. To take advantage of the potential of CMCs and to minimize risks such as component failure, modeling and analysis tools such as finite element analysis (FEA) are essential for evaluating material performance nondestructively at the operating temperatures and conditions. FEA can determine mechanical properties such as interlaminar shear properties, cumulative damage failure, and crack deviation. This chapter introduces FEA and reviews the examination and validation of the design, mechanical properties, and failure modes of CMCs using FEA.

A number of materials have been applied as implant coatings and as tissue regeneration materials. Calcium phosphate holds a special consideration, due to its chemical similarity to human bone and, most importantly, its dissolution characteristics, which allow for bone growth and regeneration. The applications of molecular and nanoscale-based biological materials have been and will continue to play an ever increasing role in enhancing and improving the osseointegration of dental and orthopedic implants. More recently, extensive research efforts have been focused on the development and applications of fluorescent nanoparticles and nanocoatings for in vivo imaging and diagnostics as well as devising methods of adding luminescent or fluorescent capabilities to enhance the in vivo functionality of calcium phosphate-based biomedical materials.

4th International Congress in Advances in Applied Physics and Materials Science (APMAS) --APR 24-27, 2014 -- Fethiye, TURKEY, WOS: 000357937100054, In this study several bioceramic materials (i.e. hydroxyapatite, whitlockite) were prepared by using chemical synthesis method from sea snail shells (Tiger Cowrie - Cypraea Tigris), originated from Pacific Ocean. Maxine shells usually present aragonite-calcite structures and generally, complicated and pressurized equipment is necessary to convert these structures into bioceramics. Instead of using complicated systems, a basic ultrasonic equipment and simple chemical synthesis method was used in the process. DTA analysis was performed to calculate the required amount of H3PO4 solution in order to set the appropriate stoichiometric ratio of Ca/P equal to 1.667 for HA bioceramic or to 1.5 for beta-TCP bioceramic in the titration. The prepared batches were sintered at 800 degrees C and 400 degrees C for hydroxyapatite (HA) and beta-tri calcium phosphate (beta-TCP) forms respectively. X-ray diffraction analysis, scanning electron microscopy (SEM) and infrared observations (FTIR) were implemented for both TCP and HA bioceramics. By applying the chemical synthesis with basic ultrasonic equipment, this study proposes a simple way of production for nano-HA /TCP powders from a natural marine sources.

International audience; Hydrothermally converted coralline hydroxyapatite (HAp) particles loaded with medically active substances were used to develop polylactic acid (PLA) thin film composites for slow drug delivery systems. The effects of HAp particles within PLA matrix on the gentamicin (GM) release and release kinetics were studied. The gentamicin release kinetics seemed to follow Power law Korsmeyer Peppas model with mainly diffusional process with a number of different drug transport mechanisms. Statistical analysis shows very significant difference on the release of gentamicin between GM containing PLA (PLAGM) and GM containing HAp microspheres within PLA matrix (PLAHApGM) devices, which PLAHApGM displays lower release rates. The use of HAp particles improved drug stabilization and higher drug encapsulation efficiency of the carrier. HAp is also the source of Ca2+ for the regeneration and repair of diseased bone tissue. The release profiles, exhibited a steady state release rate with significant antimicrobial activity against Staphylococcus aureus (S. aureus) (SH1000) even at high concentration of bacteria. The devices also indicated significant ability to control the growth of bacterial even after four weeks of drug release. Clinical release profiles can be easily tuned from drug-HAp physicochemical interactions and degradation kinetics of polymer matrix. The developed systems could be applied to prevent microbial adhesion to medical implant surfaces and to treat infections mainly caused by S. aureus in surgery.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. The theory of dissolution kinetics of gentamicin from polylactic acid-hydroxyapatite thin film composites is spotlighted with the combination of diffusion and polymer degradation modeling. The use of various mathematical models, characterizing diffusion, dissolution or/and erosion prevalence as well as a mix of dissolution-diffusion rate processes were employed in order to compare theory with experimental data. A number of factors influence the release kinetics of gentamicin from medical drug release systems and devices. It is difficult to have a single mathematical model that takes all these factors into account. It is shown that the degradation of the polymer matrix plays the biggest role in the release kinetics of polymer-ceramics thin film composites. It was also observed that multistage drug release form these devices depends also on the degradation kinetics of the polymer matrix. The effect of pH and device sizes were not studied but could also be of interest in future studies.

© Springer International Publishing AG 2017. During the past two decades, a number of materials and devices have been utilised in drug delivery applications. A range of biomaterials with different morphologies and pore sizes are currently utilised. For any given biomaterial or bioceramic, having an adequate control of the chemical composition as well as the critical pore sizes is important in terms of controlling the effectiveness when used to deliver drugs locally. In comparison to all currently known and used biomaterials, given the fact that it possesses chemical similarity to human bone, and most importantly its dissolution characteristics which allow for bone regeneration and growth, calcium phosphate holds a special consideration. Moreover, due to their interconnected pore structure, marine materials such as shells and coral exoskeletons show potential for applications in drug delivery due to their easy conversion to calcium phosphates with controllable dissolution rates. This chapter covers a range of current methods used specifically for natural materials that can be converted to calcium phosphates and mixed with polymeric materials as thin film or nanostructured drug, genes, protein and range of delivery and as anticancer chemotherapeutic devices.

International audience; The rise in the number of musculoskeletal disorders (MSDs) due to an increasingly aging population has led to a growing demand for medication to prevent and treat these diseases. An increased interest in the development of new drugs to allow treatment of these diseases in their very early stages is currently observed. The current approach on local direct delivery of medication and key minerals to support bone repair and regeneration at the defect site, from flexible degradable devices, seems to be an effective strategy. Polylactic acid (PLA) and microspheres of hydrothermally converted coralline hydroxyapatite (cHAp) were used to develop PLA thin film composites as drug delivery systems. The PLA provided flexibility and biodegradability of the systems, while coralline hydroxyapatite provided the required calcium and phosphate ions for bone regeneration. These coralline hydroxyapatite microspheres have a unique architecture of interconnected porosity, are bioactive in nature and suitable for drug loading and controlled slow drug release. The cell attachment and morphology of the PLA thin film composites were evaluated in vitro using cell cultures of human adipose derived stem cells (hADSC). It was shown that hADSC cells exhibited a strong attachment and proliferation on PLA thin film-cHAp composites, signifying high biocompatibility and a potential for osteointegration due to the presence of HAp.

© 2016 Australian Ceramic Society. The additive manufacturing of bioceramic parts has been investigated since the 1980s. This paper offers an overview of the present achievements in the production of alumina, zirconia and hydroxyapatite parts by means of selective laser sintering/melting of a powder bed or stereolithography. A focus is placed on these specific materials because of their widespread use in the biomedical field. It demonstrates that even though the manufacturing of parts with these processes is possible from pure bioceramics, the use of a binder (or another chemical adjuvant) is required in order to achieve good mechanical properties. Still, improvements in the raw material preparation and in the comprehension of the physical phenomena occurring during the processing remain necessary to be able to prevent the formation of cracks or to be able to control the porosity of the parts.

Surface modifications are usually performed on titanium alloys to improve osteo-integration and surface bioactivity. Modifications such as alkaline and acid etching, or coating with bioactive materials such as hydroxyapatite, have previously been demonstrated. The aim of this work is to develop a peptide with combined titanium oxide and hydroxyapatite binders in order to achieve a biomimetic hydroxyapatite coating on titanium surfaces. The technology would also be applicable for the functionalisation of titanium and hydroxyapatite surfaces for selective protein adsorption, conjugation of antimicrobial peptides, and adsorption of specialised drugs for drug delivery. In this work, functionalisation of Ti6Al4V and hydroxyapatite surfaces was achieved using combined titanium-hydroxyapatite (Ti-Hap) peptides based on titanium binder (RKLPDA) and hydroxyapatite binder (EEEEEEEE) peptides. Homogeneous peptide coatings on Ti6Al4V surfaces were obtained after surface chemical treatments with a 30 wt % aqueous solution of H2O2 for 24 and 48 hours. The treated titanium surfaces presented an average roughness of Sa=197 nm (24 h) and Sa=128 nm (48 h); an untreated mirror polished sample exhibited an Sa of 13 nm. The advancing water contact angle of the titanium oxide layer after 1 hour of exposure to 30 wt % aqueous solution of H2O2 was around 65°, decreasing gradually with time until it reached 35° after a 48 hour exposure, suggesting that the surface hydrophilicity increased over etching time. The presence of a lysine (L) amino acid in the sequence of the titanium binder resulted in fluorescence intensity roughly 16 % higher compared with the arginine (R) amino acid analogue and therefore the lysine containing titanium binder was used in this work. The Ti-Hap peptide KKLPDAEEEEEEEE (Ti-Hap1) was not adsorbed by the treated Ti6Al4V surfaces and therefore was modified. The modifications involved the inclusion of a glycine spacer between the binding terminals (Ti-Hap2) and the addition of a second titanium binder (KKLPDA) (Ti-Hap3 and Ti-Hap4). The Ti-Hap peptide aptamer which exhibited the strongest intensity after the titanium dip coating was KKLPDAKKLPDAEEEEEEEE (Ti-Hap4). On the other hand, hydroxyapatite surfaces, exhibiting an average roughness of Sa=1.42 µm, showed a higher fluorescence for all peptides compared with titanium surfaces.

International audience; The biodegradable and biocompatible antibiotic containing thin film composites are very appropriate biomaterials as coating materials for dental implants because of their adjustable drug loading and release rates for the prevention of implant related infections. Coralline hydroxyapatite (HAp) was loaded with gentamicin antibiotics and combined with a biodegradable polylactic acid (PLA) to form thin film composites. PLA-HAp, PLA-Gentamicin (GM) and PLA-HAp-GM composites were produced, and their dissolution studies were carried out in phosphate buffered saline under SINK conditions. It was observed that the coatings could be efficiently applied to titanium dental implants and the drug release rates can be efficiently controlled.

© 2016 John Wiley & Sons Ltd. Objectives: The aim of this study was to investigate the bone regenerative properties of a heat treated cross-linked GBR membrane with zinc hydroxyapatite powders in the rat calvarial defect model over a 6-week period. Material and Methods: In vitro physio-chemical characterization involved X-ray diffraction analysis, surface topology by scanning electron microscopy, and zinc release studies in physiological buffers. Bilateral rat calvarial defects were used to compare the Zn-HAp membranes against the commercially available collagen membranes and the unfilled defect group through radiological and histological evaluation. Results: The synthesized Zn-MEM (100 μm thick) showed no zinc ions released in the phosphate buffer solution (PBS) buffer, but zinc was observed under acidic conditions. At 6 weeks, both the micro-CT and histological analyses revealed that the Zn-MEM group yielded significantly greater bone formation with 80 ± 2% of bone filled, as compared with 60 ± 5% in the collagen membrane and 40 ± 2% in the unfilled control group. Conclusion: This study demonstrated the use of heat treatment as an alternative method to cross-linking the Zn-MEM to be applied as a GBR membrane. Its synthesis and production are relatively simple to fabricate, and the membrane had rough surface features on one side, which might be beneficial for cellular activities. In a rat calvarial defect model, it was shown that new bone formation was accelerated in comparison with the collagen membrane and the unfilled defect groups. These results would suggest that Zn-MEM has the potential for further development in dental applications.

One of the major challenges in the development of biomaterials is the adaptation of the complex elastic nature and elongation of human tissues during biomechanical functional loading. Composite materials present the most appropriate means of attempting to match the mechanical and biocompatibility requirements. Composite films from polylactic acid (PLA) and sol-gel derived bioglass (BG) powders with particle size ranging from 50-100 nm were produced by solution casting method. Three different bioglass mixtures of 0.1, 0.5 and 1% bioglass were prepared. Physico-chemical and morphological properties of bioglass, pure PLA and PLA composites were investigated using XRD, SEM and FTIR. Bioglass particles were further treated by nanolayer coating of 3-aminopropyltriethoxysilane (APTES) to improve its mechanical properties. The effects of surface treated bioglass on the fracture of the PLA/bioglass composites were investigated under tensile loading conditions. The results suggest by nano-surface treating the bioglass with 1% APTES significantly influences the percentage elongation of the PLA/bioglass composite at fracture. SEM shows more agglomeration of untreated bioglass within the composite. In the treated samples, a better distribution of nanosized bioglass within PLA matrix was observed. Nanolayer modified bioglass /PLA thin film composites may have a wide range of biomedical applications in tissue engineering with improved elastic properties. © 2014 Bentham Science Publishers.

Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP) as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair. © 2013 by the authors; licensee MDPI.

Coatings on implants are aimed to achieve some or all of the improvements in abrasion, corrosion resistance, metal ion release protection, increased bioactivity, biocompatibility, and ultimately an improved environment and structure for new bone attachment. Adhesion, mechanical properties and testing methods are used to determine the viability of coated implants or devices and their performance under simulated physiological environments. Perforation or delamination of the coatings can expose the substrate to accelerated wear or corrosion, and the released coating particles may act to accelerate third party wear resulting in a negative host response. An in-depth understanding of the adhesion of the implants and the susceptibility of the coating to cracking and delamination are critical important reliability issues. The aim of this review is to give a brief description on the various techniques used to produce micro and nanocoatings currently used or being investigated within the biomedical field. This is followed by an overview of some of the most widely used test methods for measuring mechanical properties and adhesion performance of coatings used in medical applications. © 2012 Elsevier B.V.

A vital ingredient for engineering bone tissue, in the culture dish, is the use of recombinant matrix and growth proteins to help accelerate the growth of cultivated tissues into clinically acceptable quantities. The skeletal organic matrices of calcifying marine invertebrates are an untouched potential source of such growth inducing proteins. They have the advantage of being ready-made and retain the native state of the original protein. Striking evidence shows that skeleton building bone morphogenic protein-2/4 (BMP) and transforming growth factor beta (TGF-β) exist within various marine invertebrates such as, corals. Best practice mariculture and the latest innovations in long-term marine invertebrate cell cultivation can be implemented to ensure that these proteins are produced sustainably and supplied continuously. This also guarantees that coral reef habitats are not damaged during the collection of specimens. Potential proteins for bone repair, either extracted from the skeleton or derived from cultivated tissues, can be identified, evaluated and retrieved using chromatography, cell assays and proteomic methods. Due to the current evidence for bone matrix protein analogues in marine invertebrates, together with the methods established for their production and retrieval there is a genuine prospect that they can be used to regenerate living bone for potential clinical use. © 2013 by the authors; licensee MDPI.

Biomimetic materials such as coral exoskeletons possess unique architectural structures with a uniform and interconnected porous network that can be beneficial as a scaffold material. In addition, these marine structures can be hydrothermally converted to calcium phosphates, while retaining the original structural properties. The ability of biomaterials to stimulate the local microenvironment is one of the main focuses in tissue engineering, and directly coating the scaffold with stem cells facilitates future potential applications in therapeutics and regenerative medicine. In this article we describe a new and simple method that uses a laboratory centrifuge to coat hydrothermally derived beta-tricalcium phosphate macrospheres from coral exoskeleton with stem cells. In this research the optimal seeding duration and speed were determined to be 1 min and 700 g. Scanning electron micrographs showed complete surface coverage by stem cells within 7 days of seeding. This study constitutes an important step toward achieving functional tissue-engineered implants by increasing our understanding of the influence of dynamic parameters on the efficiency and distribution of stem cell attachment to biomimetic materials and how stem cells interact with biomimetic materials., published_or_final_version

With the global rise in aging of populations, the occurrence of osteoporosis will continue to increase. Biomaterial and pharmaceutical scientists continue to develop innovative strategies and materials to address this disease. In this article, we describe a new perspective and approach into the use of coral exoskeletons as a precursor material to synthesize a calcium phosphate-based drug delivery system. Studies detailing the methodology of the conversion methods and the strategies and approach for the development of these novel drug delivery systems are described. Furthermore, in vivo studies in osteoporotic mice using a drug loaded and chemically modified version of the biomimetic delivery system showed significant cortical and cancellous bone increases. These studies support the notion and the rationale for future research and development of the use of coral exoskeletons as materials for drug delivery applications.

© Springer-Verlag GmbH Germany 2017. Tissue engineering and advanced biomedical technologies have proved to be potential to improve the quality of human life. During the last four decades, the capability to engineer or repair new functional tissues has been a very effective approach to improve the quality of life of patients. Since its discovery by Hench and co-workers in the 1960s, bioglasses and glass ceramics have attracted considerable attention of many researchers because of their unique properties which can easily be tailored by manipulating its compositions and morphology. Over the years, many questions concerning its interactions with both hard and soft tissues have been answered with a multidisciplinary team of surgeons, scientists and engineers. Many clinical Bioglass® and other similar structures and compositions are being used for bone augmentation and restoration, in orthopaedic, dental and maxillofacial surgery and in general in the field of tissue engineering. They have proved to be efficient and effective, some with outperformance over other bioceramic and metal prostheses. It is our aim in this chapter to present the development of these important biomaterials focusing on the history, synthesis, properties, modern characterisation methods and the current development of nano- and biocomposite materials for clinical applications.

International audience; Three-dimensionally ordered macroporous bioactive SiO2-CaO-Na2O-P2O5 glass (3DOM-BG) is synthesized by using the sol-gel method. After an in vitro test in simulated body fluid (SBF), the hydroxyapatite (HAp) crystalline phase is clearly formed on its surface as confirmed by X-ray diffractometry (XRD) and Raman spectroscopy. Magnetic 3DOM-BG/Fe samples are synthesized by partial substitution of SiO2 with iron oxide. Whilst the HAp layer is not confirmed, energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and XRD analysis reveal calcium phosphate layer on the surface of 3DOM-BG/Fe samples after the SBF soaking. The growth of HAp-like layer is slower with increasing iron oxides. The initial mechanism that thought to induce bone formation is reduced due to the replacement of Ca2+ with Fe ions in the glass network. The formation of HAp-like layer is modified by the sedimentation of Ca and P while the nonmagnetic 3DOM-BG forms the calcium phosphate by the ionic exchange following the Hench mechanism. The adult human adipose tissue-derived stem cells (hADSCs) can be closely attached and well spread on the flat-plate of all 3DOM-BG/Fe and 3DOM-BG. Without detectable cytotoxicity possibly induced by iron oxides, the osteoblast can be grown and proliferated. In addition to these bioactivity and biocompatibility, porous structures can allow their possible use in targeted drug delivery and magnetic properties of 3DOM-BG/Fe can essentially be implemented in hyperthermia therapy.

© Springer International Publishing Switzerland 2016. During the last two decades, biomimetics has provided mankind new directions for the utilization of natural organic and inorganic skeletons for novel drug delivery systems and new medical treatment approaches with unique designs ranging from the macro- to the nanoscale. The use of ready-made organic and inorganic marine skeletons has potentially created an opportunity of presenting one of the simplest cures to fundamental issues hampering the future development of regenerative medicine, dentistry, and orthopedics such as providing a richness of framework designs and devices and abundant and available sources of osteopromotive analogues and biomineralization proteins. Organic matrix and inorganic marine skeletons possess a habitat ideal for the proliferation of added mesenchymal stem cell populations and promoting clinically acceptable bone formation. It has been proven that self-sustaining musculoskeletal tissues can be supported by coral and marine sponge skeletons, and bone mineralization can be promoted by the extracts of spongin collagen and nacre seashell organic matrices. This idea is reinforced by the fact that bone morphogenetic protein molecules are produced by endodermal cells into the developing skeleton. Furthermore, the regenerative signaling proteins in bone therapeutics such as TGF and Wnt are also present in early marine sponge development and instrumental to the activation of stem cells in cnidarians. This chapter aims to give a brief background into the nature, morphology, and application of some of these structures in bone grafts, drug delivery, tissue engineering, and specific extracts such as proteins for regenerative medicine.

© 2016 Trans Tech Publications, Switzerland. Drug delivery systems were developed from coralline hydroxyapatite (HAp) and biodegradable polylactic acid (PLA). Gentamicin (GM) was loaded in either directly to PLA (PLAGM) or in HAp microspheres. Drug loaded HAp was used to make thin film composites (PLAHApGM). Dissolution studies were carried out in phosphate buffered saline (PBS). The release profiles suggested that HAp particles improved drug stabilization and availability as well controlled the release rate. The release also displays a steady state release. In vitro studies in human Adipose Derived Stem Cells (hADSCs) showed substantial quantities of cells adhering to hydroxyapatite containing composites. The results suggested that the systems could be tailored to release different clinical active substances for a wide range of biomedical applications.