Biomineralization Ability Research Articles

Polydopamine modified TiO2 nanotube arrays as a local drug delivery system for ibuprofen

Dopamine with multifunctional groups exhibits excellent biological activity and self-polymerization ability, which provides active groups for secondary reaction on the different kinds of modified surface. In this study, using the ultrasonic method, dopamine polymer coatings functionalized on TiO2 nanotube arrays (TNTs) were successfully prepared. The obtained samples were characterized and evaluated using field-emission scanning electron microscopy (FESEM), transmission electron microscope (TEM) and atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). Upon dopamine self-polymerization, due to the presence of multifunctional groups, it could interact with drug molecules to efficiently enhance drug loading, prevent drug sudden release and improve sustained-release performance of the carrier. TNTs were loaded with ibuprofen (IBU) via soaking method before and after modification and its release properties were investigated. The results showed that dopamine-modified TNTs remarkably improved the loading of IBU and prolonged drug release. Notably, the biomineralization ability of the sample was also tremendously enhanced through modification of the nanotubes with polydopamine. In conclusion, dopamine-modified TNTs may be a promising approach in promoting the loading of IBU and sustained the drug release that is noticeably essential for bone implant therapies.

Beneficial factors for biomineralization by ureolytic bacterium Sporosarcina pasteurii

BackgroundThe ureolytic bacterium Sporosarcina pasteurii is well-known for its capability of microbially induced calcite precipitation (MICP), representing a great potential in constructional engineering and material applications. However, the molecular mechanism for its biomineralization remains unresolved, as few studies were carried out.ResultsThe addition of urea into the culture medium provided an alkaline environment that is suitable for S. pasteurii. As compared to S. pasteurii cultivated without urea, S. pasteurii grown with urea showed faster growth and urease production, better shape, more negative surface charge and higher biomineralization ability. To survive the unfavorable growth environment due to the absence of urea, S. pasteurii up-regulated the expression of genes involved in urease production, ATPase synthesis and flagella, possibly occupying resources that can be deployed for MICP. As compared to non-mineralizing bacteria, S. pasteurii exhibited more negative cell surface charge for binding calcium ions and more robust cell structure as nucleation sites. During MICP process, the genes for ATPase synthesis in S. pasteurii was up-regulated while genes for urease production were unchanged. Interestingly, genes involved in flagella were down-regulated during MICP, which might lead to poor mobility of S. pasteurii. Meanwhile, genes in fatty acid degradation pathway were inhibited to maintain the intact cell structure found in calcite precipitation. Both weak mobility and intact cell structure are advantageous for S. pasteurii to serve as nucleation sites during MICP.ConclusionsFour factors are demonstrated to benefit the super performance of S. pasteurii in MICP. First, the good correlation of biomass growth and urease production of S. pasteurii provides sufficient biomass and urease simultaneously for improved biomineralization. Second, the highly negative cell surface charge of S. pasteurii is good for binding calcium ions. Third, the robust cell structure and fourth, the weak mobility, are key for S. pasteurii to be nucleation sites during MICP.

Effects of statherin on the biological properties of titanium metals subjected to different surface modification

The failure of dental implants is usually caused by bacteria infection, poor bioactivity and biocompatibility. It is a common phenomenon clinically. Statherin, a salivary protein, plays a crucial role of mediator between materials and cells/bacteria. However, the conformation of statherin might be changed by the implants in vivo. In this study, we investigated the effects of statherin on the bioactivities, antibacterial abilities and biocompatibilities of the titanium metals and the reaction mechanism. We found that the conformation of statherin was mainly influenced by surface composition, surface structure, surface roughness, surface hydrophilia and Ti−OH groups of materials. Statherin could decrease the cell biocompatibility of the titanium metals including pure titanium (PT), anodic oxidation (AO), sandblasting and etching (SLA) and plasma spraying hydroxyapatite (HA) coating in HGF cell experiments, regulate the bio-mineralization ability of HA coating in SBF, and enhance the antibacterial properties of PT and HA coating. This study revealed that surface properties of materials could change the conformation of statherin, which influenced the bioactivities, antibacterial properties and biocompatibilities of the materials in return.

Substantial effect of silk fibroin reinforcement on properties of hydroxyapatite/silk fibroin nanocomposite for bone tissue engineering application

Nano-biocomposites that mimics bone’s extracellular matrix with hydroxyapatite as an inorganic and silk fibroin as organic phase for three different ratios via a simple in-situ co-precipitation method have been synthesized. The silk fibroin, a biodegradable polymer from cocoons of Bombyx mori silkworm were extracted by employing a chemical-free High-Temperature High-Pressure method as a degumming route. Then followed by the regeneration process which was done by using calcium chloride-formic acid solvent system to replace time-consuming, cost-effective traditional methods. The prepared composites were structurally analyzed using Fourier Transform Infra-Red spectroscopy (FTIR) and X-ray Diffraction (XRD) techniques. The morphology and the elemental composition of the nano-biocomposites were examined using Field Emission Scanning Electron Microscopy (FESEM) and Energy-dispersive X-ray Spectroscopy (EDX). The in-vitro bioactivity of the bio-composites namely, swelling ratio, biodegradation and biomineralization ability is monitored in the presence of Simulated Body Fluid (SBF). Our observation demonstrate that silk fibroin concentration influences the formation of hydroxyapatite.

Enhanced corrosion resistance and biocompatibility of polydopamine/dicalcium phosphate dihydrate/collagen composite coating on magnesium alloy for orthopedic applications

Magnesium (Mg) and its alloys have been suggested as a promising next-generation orthopedic implant material. However, fast degradation in the physiological environment and potential cytotoxicity hinder their further clinic application. To enhance the biocorrosion resistance and cytocompatibility of Mg alloys, a multifunctional composite coating composed of polydopamine (PDA), dicalcium phosphate dihydrate (DCPD), collagen (Col) was prepared by a two-step chemical method. The surface morphology, chemical composition, thickness, corrosion performance, and cytotoxicity of the coating were investigated. The results showed that the PDA/DCPD/Col coating significantly improved the biocorrosion resistance and biomineralization ability of Mg alloys. Moreover, the PDA/DCPD/Col coating has a similar composition to natural bone, providing a more favorable interface for cell viability and adhesion. The PDA/DCPD/Col coating greatly enhanced the cytocompatibility and osteogenic differentiation ability compared with Mg alloy and PDA/DCPD coating. With enhanced cytocompatibility, osteogenic differentiation ability and corrosion resistance, the PDA/DCPD/Col composite coating exhibits great potential in bone tissue engineering.

3D Porous poly(lactic acid)/regenerated cellulose composite scaffolds based on electrospun nanofibers for biomineralization

One of the serious challenges in bone tissue engineering is the construction of biomimetic scaffolds, which can bridge the gap between mechanical strength and porous structure requirements. Although electrospinning technology can be used to create nanofibrous networks with a structure of artificial extracellular matrix (ECM), the restricted shapes and pore sizes block its application. Herein, we combine technologies of freeze-drying and crosslinking to fabricate a novel three-dimensional (3D) poly(lactic acid)/regenerated cellulose (PLA/RC) scaffold. Owing to the introduction of RC nanofibers, the hydrophilicity and biological activity has been improved. Moreover, citric acid works as a non-toxic crosslinker to participate in the esterification-crosslinking reaction with RC nanofibers, and its unreacted −COOH groups can also endow the 3D scaffolds with apatite-nucleating capacity to further boost osteogenic potential. The resulting PLA/RC nanofiber-reconfigured scaffolds present the characteristics of high water absorption, hierarchical cellular structure and fast recovery from 80% strain. Notably, the well-designed PLA/RC scaffolds with abundant hydroxyl groups and carboxyl groups exhibit the excellent biomineralization ability in the SBF solution. And the formation of bonelike apatite not only can buffer the acid degradation products from PLA, but also will be beneficial to scaffold-to-bone bonding in the process of implantation. It is significant that the whole preparation process is safe, green and economical, which can well satisfy the demands of biomedical materials. Thus, the developed 3D PLA/RC scaffold is promising in the field of bone tissue engineering application.

Bacillus cereus s-EPS as a dual bio-functional corrosion and scale inhibitor in artificial seawater

In this study, soluble extracellular polymeric substances (s-EPS) secreted by Bacillus cereus (B. cereus) were studied as a novel, dual bio-functional corrosion and scale inhibiting material, in artificial seawater. Static tests showed that the scale inhibition efficiency (SI%) was close to 87.60% for CaCO3 at the concentration of 80 mg/L s-EPS. Electrochemical technique results showed that s-EPS inhibition efficiencies, in relation to 316L stainless steel (SS), and at the concentration of 40 mg/L, reached 91.05% at 10 d and 91.16% at 30 d, respectively. The high anti-scale and anti-corrosion performance of s-EPS was related to their chelating, adsorption, and biomineralization abilities. s-EPS integrated with metal ions on the SS surface, resulting in formation of a thin but dense biomineralized film, which exhibited lasting corrosion resistance. Meanwhile, s-EPS controlled the kinetic pathway of CaCO3 biomineralized nucleation and crystal growth, which inhibited CaCO3 crystal precipitation. This finding suggests that B. cereus s-EPS may offer a green, sustainable, and economic strategy for anti-corrosion and anti-scale application in industry.

3D-printed photoluminescent bioactive scaffolds with biomimetic elastomeric surface for enhanced bone tissue engineering.

Three dimensional (3D) printed porous bioactive glass nanoparticles scaffolds (BGNS) exhibit excellent bone integration and bone regeneration capacities, but the early rapid ion release, brittle mechanical properties and lack of functions limit their application. In this work, photoluminescent biomimetic elastomeric BGNS were fabricated by directly assembling poly(citrate-siloxane) (PCS) on the surface of BGNS (BGNS@PCS). The morphologies, mechanical behavior, photoluminescent ability, ions release, biomineralization activity, biocompatibility and osteogenic properties of BGNS@PCS were evaluated in detail. The results indicated that BGNS@PCS presented superior elasticity and outstanding compressive strength compared with BGNS. The controlled release of the Si and Ca ions in BGNS@PCS was achieved and enhanced biomineralization ability was also observed. In addition, the modified scaffolds have the photoluminescent ability which has the potential application for bioimaging. BGNS@PCS could significantly promote cells attachment, proliferation and enhance osteogenic differentiation of mouse bone marrow stromal cells (BMSCs). Therefore, the BGNS@PCS with the multifunctional properties including elastomeric surface, enhanced photoluminescent, controlled ions release and biomineralization, reinforced osteogenic activity, would be a promising candidate for bone tissue regeneration. This study probably provides a novel strategy to design biomimetic elastomeric bioceramic scaffolds for hard tissue regeneration.

Novel Insights into Regulation of Human Teeth Biomineralization: Deciphering the Role of Post-Translational Modifications in a Tooth Protein Extract.

The importance of whole protein extracts from different types of human teeth in modulating the process of teeth biomineralization is reported. There are two crucial features in protein molecules that result in efficient teeth biomineralization. Firstly, the unique secondary structure characteristics within these proteins i.e. the exclusive presence of a large amount of intrinsic disorder and secondly, the presence of post-translational modifications (PTM) like phosphorylation and glycosylation within these protein molecules. The present study accesses the structural implications of PTMs in the tooth proteins through scanning electron microscopy and transmission electron microscopy. The deglycosylated/dephosphorylated protein extracts failed to form higher-order mineralization assemblies. Furthermore, through nanoparticle tracking analysis (NTA) we have shown that dephosphorylation and deglycosylation significantly impact the biomineralization abilities of the protein extract and resulted in smaller sized clusters. Hence, we propose these post-translational modifications are indispensable for the process of teeth biomineralization. In addition to basic science, this study would be worth consideration while designing of biomimetics architecture for an efficient peptide-based teeth remineralization strategy.

Sulfated Polysaccharides from Macroalgae for Bone Tissue Regeneration.

Utilization of macroalgae has gained much attention in the field of pharmaceuticals, nutraceuticals, food and bioenergy. Macroalgae has been widely consumed in Asian countries as food from ancient days and proved that it has potential bioactive compounds which are responsible for its nutritional properties. Macroalgae consists of a diverse range of bioactive compounds including proteins, lipids, pigments, polysaccharides, etc. Polysaccharides from macroalgae have been utilized in food industries as gelling agents and drug excipients in the pharmaceutical industries owing to their biocompatibility and gel forming properties. Exploration of macroalgae derived sulfated polysaccharides in biomedical applications is increasing recently. In the current review, we have provided information of three different sulfated polysaccharides such as carrageenan, fucoidan and ulvan and their isolation procedure (enzymatic precipitation, microwave assisted method, and enzymatic hydrolysis method), structural details, and their biomedical applications exclusively for bone tissue repair and regeneration. From the scientific results on sulfated polysaccharides from macroalgae, we conclude that sulfated polysaccharides have exceptional properties in terms of hydrogel-forming ability, scaffold formation, and mimicking the extracellular matrix, increasing alkaline phosphatase activity, enhancement of biomineralization ability and stem cell differentiation for bone tissue regeneration. Overall, sulfated polysaccharides from macroalgae may be promising biomaterials in bone tissue repair and regeneration.

Carbon Dioxide Sequestering Ability of Bacterial Carbonic Anhydrase in a Mangrove Soil Microcosm and Its Bio-mineralization Properties

In this study, we attempt to prospect potential bacterial isolates from mangrove sediments of Mangalavanam, Kerala, India, with positive carbonic anhydrase (CA) activity to sequester carbon dioxide by calcium precipitation process. Fifteen bacterial colonies (M1–M15) isolated were screened for their carbonic anhydrase enzyme production potential based on p-nitro phenol acetate assay. Based on the secondary screening, M3 and M8 were identified as the most potential for carbonic anhydrase production. The specific activity of the partially purified CA enzyme from M3 and M8 were 44 U mg−1 and 76 U mg−1 respectively. The enzyme activity increased by 1.6-fold upon precipitation by acetone (80%). The potential isolate which higher CA production, M8 was identified as Bacillus altitudinis based on 16S rDNA sequencing. Soil microcosm was established to study carbonic anhydrase production and CO2 sequestration ability of B. altitudinis M8 strain. B. altitudinis M8 strain could reduce CO2 by 75 ± 0.12% in microcosm composed of sterilized soil with bacteria (SSB) and by 97 ± 0.34% in microcosm with sterile soil with enzyme (SSE). Hence, the application of enzyme was found to be more effective in removing CO2 when compared to bacterial inoculum. To further understand the bio-mineralization ability of this microbial isolate, calcium precipitation assay was conducted. There was a reduction of 42.22 ± 0.23% of free calcium in the medium through calcite precipitation. The carbonic anhydrase-mediated calcium precipitation by B. altitudinis M8 strain could be effectively employed in the process of carbon dioxide sequestration.

Monodisperse Branched Molybdenum‐Based Bioactive Nanoparticles Significantly Promote Osteogenic Differentiation of Adipose‐Derived Stem Cells

AbstractAdipose‐derived stem cells (ADSCs) are considered to be ideal stem cell sources for bone‐tissue regeneration owing to their ease of collection and high activity. However, the regulation of osteogenic differentiation of ADSCs using biomaterials without adding growth factors is still not satisfactory. For the first time, molybdenum‐doped bioactive glass nanoparticles with a radial porous morphology (Mo‐rBGNs) are reported and their role in the osteogenic differentiation of ADSCs is investigated. The results show that Mo‐rBGNs exhibit radially porous and spherical morphology, relatively homogeneous particle size (200–400 nm), and excellent apatite‐forming bioactivity. They do not affect the proliferation of ADSCs, but significantly regulate their osteogenic differentiation and biomineralization. 5% Mo‐rBGNs significantly enhance the alkaline phosphatase activity and biomineralization ability and promote the osteogenic gene expressions of collagen I secretion and bone sialo protein in ADSCs. A reasonable and promising strategy for designing nanoscale bioactive materials with the excellent osteogenic ability for stem cell–based bone tissue regeneration is provided.

Graphene oxide and montmorillonite enriched natural polymeric scaffold for bone tissue engineering

Abstract In this study, the synergistic effect of graphene oxide (GO) and Montmorillonite (MMT) additives on the chemical, physical, mechanical, and biological properties of chitosan-gelatin (CS-Gel) scaffolds samples were investigated. FT-IR, XRD, Raman spectroscopy, and zeta potential analysis were used to investigate the accuracy of GO synthesis. Morphological studies of scaffold samples showed highly porous structure of all scaffold samples. The water absorption values of CS-Gel/GO and CS-Gel/GO/MMT samples were almost the same, but the highest value of water retention was observed for CS-Gel/GO scaffold. All scaffold samples showed the ability to form biomineral on the surface when exposed to SBF, although CS-Gel/GO/MMT scaffold had the best biomineralization ability. Considerable improvement in mechanical properties of scaffold samples were observed for CS-Gel/GO/MMT in comparison to CS-Gel scaffold, from 17.56 to 22.73 MPa for Young's modulus and from 0.14 to 0.2265 MPa for compressive strength. Protein adsorption of the scaffold was almost doubled in CS-Gel/GO/MMT samples compared to CS-Gel scaffold. Cell viability results indicated that none of the samples were cytotoxic and 30% of improvement in cell viability was observed for CS-Gel/GO/MMT scaffold in comparison to CS-Gel samples after 72 h of incubation.

Robust hierarchical porous MBG scaffolds with promoted biomineralization ability.

Although bioactive glasses have been traditionally used in the clinical practice for a long period, their uncontrollable architecture and poor mechanical robustness remains a neck bottle for further biomedical applications. In this study, we firstly developed a series of mesoporous bioactive glass (MBG) nanorods with different aspect ratios and adjustable pore sizes via a thermal-mediation approach. The nanorods were then dispersed in MBG sol, followed by impregnation with sponge and in situ gelation. After sinter treatment, the sponge template was removed to offer interconnected macroporous structure, while the intercross-linked MBG nanorods afford meso- and micro- pores. The resulting scaffolds presented a 2-fold reinforcement in compressive strength (1.03 MPa) which is matchable to that of cancellous bone. When their mesopore size was tuned to 7.38 nm, the scaffolds enabled an optimal protein adsorption capacity and sustainable release property. Upon 3-day incubation in simulated body fluid, the scaffolds with macro/meso/micro porous structure present more needle-like hydroxyapatites, indicating their promoted biomineralization capacity. After culture with rat bone marrow stromal cells for 1 day, the hierarchical porous scaffolds displayed good cell attachment and proliferation ability, suggesting their potential as a kind of scaffolds for tissue engineering.

Biocompatibility and biomineralization ability of Bio-C Pulpecto. A histological and immunohistochemical study.

To evaluate the inflammatory response, biomineralization and production of osteocalcin (OCN), osteopontin (OPN), and bone sialoprotein (BSP) of a new root filling material for primary teeth (Bio-C Pulpecto) compared to MTA. Polyethylene tubes containing Bio-C Pulpecto, MTA, and empty tubes were implanted into the dorsal connective tissue. After 7, 15, 30, 60, and 90days, the tubes with surrounding tissue were removed and histologically processed to be analysed using haematoxylin and eosin, von Kossa staining, or no staining for observation under polarized light and immunohistochemistry for the detection of OCN, OPN, and BSP. The Kruskal-Wallis test was used followed by Dunn's test. The significance level was set at 5%. The inflammatory response observed with MTA and Bio-C Pulpecto was more exacerbated until the 15th day and decreased from 30days on. No significant difference was found between control, MTA, and Bio-C Pulpecto (P>0.05). Bio-C Pulpecto and MTA showed positivity for von Kossa and birefringent to polarized light. The immunolabelling for OCN, OPN, and BSP was more intense for MTA and Bio-C Pulpecto on days 60 and 90 (P>0.05). Bio-C Pulpecto was biocompatible, induced biomineralization and was immunopositive for osteogenic markers such as OCN, OPN, and BSP, similarly to MTA.

Graphene oxide and amin-modified graphene oxide incorporated chitosan-gelatin scaffolds as promising materials for tissue engineering

In this work, the effect of graphene-based materials on the physicochemical, mechanical, and biological properties of chitosan-gelatin scaffolds was investigated. Graphene oxide (GO) and amine-modified graphene oxide (GNH2) were synthesized and covalently linked to the polymeric chains of chitosan and gelatin, using glutaraldehyde as a crosslinking agent. The accuracy of synthesis of graphene-based materials was verified using FT-IR, XRD, Raman, and Zeta potential techniques. The negatively and positively charged surfaces of respectively GO and GNH2 nanosheets were of great importance affecting the physicochemical properties of scaffolds; higher pore size, interconnectivity, better water absorption and retention capability, shape retention, porosity, and density compared to those of chitosan-gelatin scaffold as a control sample.All scaffolds showed biomineralization ability in vitro. Also, less biodegradation was observed for modified scaffolds. Improved mechanical properties of GO and GNH2 incorporated scaffolds were observed. Cell viability of modified scaffolds was improved by 10 and 4% respectively for GO and GNH2, compared to chitosan-gelatin scaffold.

Rapid formation of brushite flakes on pyrolytic carbon modified carbon fibers by pulsed electrodeposition

Brushite flakes are rapidly synthesized on pyrolytic carbon modified carbon fibers (PCF) by pulsed electrodeposition (PED) method. The maximum length of the brushite flakes could reach 63.5 μm in 10 s and 423.7 μm in 20 min. The formation mechanism of the brushite flakes is proposed, identifying the influence of fiber-shaped substrate, surface oxygen-containing functional group and PED preparation method. Moreover, good biomineralization ability of the brushite flakes is confirmed by in-vitro test in simulated body fluid. The brushite flakes prepared by this method has the potential applications as bioactive coatings, biological reinforcements, biological fillers and scaffolds for tissue engineering.

Bioactive Carbon-Based Hybrid 3D Scaffolds for Osteoblast Growth.

Bone, nerve, and heart tissue engineering place high demands on the conductivity of three-dimensional (3D) scaffolds. Fibrous carbon-based scaffolds are excellent material candidates to fulfill these requirements. Here, we show that highly porous (up to 94%) hybrid 3D framework structures with hierarchical architecture, consisting of microfiber composites of self-entangled carbon nanotubes (CNTs) and bioactive nanoparticles are highly suitable for growing cells. The hybrid 3D structures are fabricated by infiltrating a combination of CNTs and bioactive materials into a porous (∼94%) zinc oxide (ZnO) sacrificial template, followed by the removal of the ZnO backbone via a H2 thermal reduction process. Simultaneously, the bioactive nanoparticles are sintered. In this way, conductive and mechanically stable 3D composites of free-standing CNT-based microfibers and bioactive nanoparticles are formed. The adopted strategy demonstrates great potential for implementing low-dimensional bioactive materials, such as hydroxyapatite (HA) and bioactive glass nanoparticles (BGN), into 3D carbon-based microfibrous networks. It is demonstrated that the incorporation of HA nanoparticles and BGN promotes the biomineralization ability and the protein adsorption capacity of the scaffolds significantly, as well as fibroblast and osteoblast adhesion. These results demonstrate that the developed carbon-based bioactive scaffolds are promising materials for bone tissue engineering and related applications.

High-Throughput Microfluidic Sorting of Live Magnetotactic Bacteria.

Magnetic nanoparticles (MNPs) are useful for many biomedical applications, but it is challenging to synthetically produce them in large numbers with uniform properties and surface functionalization. Magnetotactic bacteria (MTB) produce magnetosomes with homogenous sizes, shapes, and magnetic properties. Consequently, there is interest in using MTB as biological factories for MNP production. Nonetheless, MTB can only be grown to low yields, and wild-type strains produce low numbers of MNPs/bacterium. There are also limited technologies to facilitate the selection of MTB with different magnetic contents, such as MTB with compromised and enhanced biomineralization ability. Here, we describe a magnetic microfluidic platform combined with transient cold/alkaline treatment to temporarily reduce the rapid flagellar motion of MTB without compromising their long-term proliferation and biomineralization ability for separating MTB on the basis of their magnetic contents. This strategy enables live MTB to be enriched, which, to the best of our knowledge, has not been achieved with another previously described magnetic microfluidic device that makes use of ferrofluid and heat. Our device also facilitates the high-throughput (25,000 cells/min) separation of wild-type Magnetospirillum gryphiswaldense (MSR-1) from nonmagnetic ΔmamAB MSR-1 mutants with a sensitivity of up to 80% and isolation purity of up to 95%, as confirmed with a gold-standard fluorescent-activated cell sorter (FACS) technique. This offers a 25-fold higher throughput than other previously described magnetic microfluidic platforms (1,000 cells/min). The device can also be used to isolate Magnetospirillum magneticum (AMB-1) mutants with different ranges of magnetosome numbers with efficiencies close to theoretical estimates. We believe this technology will facilitate the magnetic characterization of genetically engineered MTB for a variety of applications, including using MTB for large-scale, controlled MNP production.IMPORTANCE Our magnetic microfluidic technology can greatly facilitate biological applications with magnetotactic bacteria, from selection and screening to analysis. This technology will be of interest to microbiologists, chemists, and bioengineers who are interested in the biomineralization and selection of magnetotactic bacteria (MTB) for applications such as directed evolution and magnetogenetics.

Hydroxyapatite from Cuttlefish Bone: Isolation, Characterizations, and Applications

Hydroxyapatite (HA), a bioceramic, is a widely utilized material for bone tissue repair and regeneration because of its excellent properties such as biocompatibility, exceptional mechanical strength, and osteoconductivity. HA can be obtained by both synthetic and natural means. Animal bones are often considered a promising natural resource for the preparation of pure HA for biological and biomedical applications. Cuttlefish bone, also called as cuttlebone, mainly consists of calcium carbonate, and pure HA can be produced by adding phosphoric acid or ammonium hydrogen phosphate to it. Recently, cuttlefish bone-derived HA has shown promising results in terms of bone tissue repair and regeneration. The synthesized cuttlefish bone-derived has shown excellent biocompatibility, cell proliferation, increased alkaline phosphate activity, and efficient biomineralization ability with mesenchymal stem cells and osteoblastic cells. To further improve the biological properties of cuttlefish bone-derived HA, bioglass, polycaprolactone, and polyvinyl alcohol were added to it, which gave better results in terms of cell proliferation and osteogenic differentiation. Cuttlefish bone-derived HA with polymeric substances provides excellent bone formation under in vivo conditions. The studies indicate that cuttlefish bone-derived HA, along with polymeric and, protein materials, will be promising biomaterials in the field of bone tissue regeneration.