Phosphate Deposits Research Articles

Targeting TREM2 signaling shows limited impact on cerebrovascular calcification.

Brain calcification, the ectopic mineral deposits of calcium phosphate, is a frequent radiological finding and a diagnostic criterion for primary familial brain calcification. We previously showed that microglia curtail the growth of small vessel calcification via the triggering receptor expressed in myeloid 2 (TREM2) in the Pdgfb ret/ret mouse model of primary familial brain calcification. Because boosting TREM2 function using activating antibodies has been shown to be beneficial in other disease conditions by aiding in microglial clearance of diverse pathologies, we investigated whether administration of a TREM2-activating antibody could mitigate vascular calcification in Pdgfb ret/ret mice. Single-nucleus RNA-sequencing analysis showed that calcification-associated microglia share transcriptional similarities to disease-associated microglia and exhibited activated TREM2 and TGFβ signaling. Administration of a TREM2-activating antibody increased TREM2-dependent microglial deposition of cathepsin K, a collagen-degrading protease, onto calcifications. However, this did not ameliorate the calcification load or alter the mineral composition and the microglial phenotype around calcification. We therefore conclude that targeting microglia with TREM2 agonistic antibodies is insufficient to demineralize and clear vascular calcifications.

The Remineralization of Enamel from Saliva: A Chemical Perspective

The natural remineralization of enamel is of major importance for oral health. In principle, early erosions (demineralization) induced by acidic beverages and foods as well as initial caries lesions can be covered and remineralized by the deposition of calcium phosphate, i.e., tooth mineral. This remineralization effect is characterized by the presence of calcium and phosphate ions in saliva that form hydroxyapatite on the enamel surface. Although it is apparently a simple crystallization, it turns out that remineralization under in vivo conditions is actually a very complex process. Calcium phosphate can form a number of solid phases of which hydroxyapatite is only one. Precipitation involves the formation of metastable phases like amorphous calcium phosphate that convert into biological apatite in a number of steps. Nanoscopic clusters of calcium phosphate that can attach on the enamel surface are also present in saliva. Thus, remineralization under strictly controlled in vitro conditions (e.g., pH, ion concentrations, no additives) is already complex, but it becomes even more complicated under the actual conditions in the oral cavity. Here, biomolecules are present in saliva, which interact with the forming calcium phosphate mineral. For instance, there are salivary proteins which have the function of inhibiting crystallization to avoid overshooting remineralization. Finally, the presence of bacteria and an extracellular matrix in plaque and the presence of proteins in the pellicle have strong influences on the precipitation on the enamel surface. The current knowledge on the remineralization of the enamel is reviewed from a chemical perspective with a special focus on the underlying crystallization phenomena and the effects of biological compounds that are present in saliva, pellicle, and plaque. Basically, the remineralization of enamel follows the same principles as calculus formation. Notably, both processes are far too complex to be understood on a microscopic basis under in vivo conditions, given the complicated process of mineral formation in the presence of a plethora of foreign ions and biomolecules.

Extracorporeal Magnetotransduction Therapy as a New Form of Electromagnetic Wave Therapy: From Gene Upregulation to Accelerated Matrix Mineralization in Bone Healing.

Electromagnetic field therapy is gaining attention for its potential in treating bone disorders, with Extracorporeal Magnetotransduction Therapy (EMTT) emerging as an innovative approach. EMTT offers a higher oscillation frequency and magnetic field strength compared to traditional Pulsed Electromagnetic Field (PEMF) therapy, showing promise in enhancing fracture healing and non-union recovery. However, the mechanisms underlying these effects remain unclear. This study demonstrates that EMTT significantly enhances osteoblast bone formation at multiple levels, from gene expression to extracellular matrix mineralization. Key osteoblastogenesis regulators, including SP7 and RUNX2, and bone-related genes such as COL1A1, ALPL, and BGLAP, were upregulated, with expression levels surpassing those of the control group by over sevenfold (p < 0.001). Enhanced collagen synthesis and mineralization were confirmed by von Kossa and Alizarin Red staining, indicating increased calcium and phosphate deposition. Additionally, calcium imaging revealed heightened calcium influx, suggesting a cellular mechanism for EMTT's osteogenic effects. Importantly, EMTT did not compromise cell viability, as confirmed by live/dead staining and WST-1 assays. This study is the first to show that EMTT can enhance all phases of osteoblastogenesis and improve the production of critical mineralization components, offering potential clinical applications in accelerating fracture healing, treating osteonecrosis, and enhancing implant osseointegration.

7984 A Challenging Case Of Hyperphosphatemic Familial Tumoral Calcinosis

Abstract Disclosure: T.G. de Souza: None. T.J. Weber: None. Introduction: Hyperphosphatemic Familial Tumoral Calcinosis (hFTC) is a rare, autosomal recessive metabolic disorder characterized by elevated serum phosphate levels and the accumulation of calcium phosphate deposits in soft tissues. There are fewer that 150 genetically confirmed cases in the literature. There are no consensus guidelines; therapeutic approaches are guided by case reports or series. This case serves to heighten awareness of therapeutic strategies including global health considerations for the disabled adult with a rare bone disorder. Case: A 32-year-old African-American woman presented to establish care for hFTC, for which she takes ibuprofen for disabling bilateral hip pain. hFTC was diagnosed in early childhood and managed at a large children’s hospital. Therapeutic modalities relied on operative resection of skin lesions on eruption. She describes cosanguinous parentage, consignment to foster care as a child and homelessness as an adult. She has not had adult endocrine care for her hFTC. Her medical comorbidities include major depressive disorder, PTSD and suicide attempt. She reports one uncle with hFTC noting that his phenotype was not significantly disabling and apparent recession of his lesions with age. Her parents did not have symptoms of hFTC. Radiographically, she had amorphous calcium deposits over both hips (her primary sites of severe pain), upper back (site of painless spontaneous eruptions), and left elbow without pain or skin penetration, as well as hyperostosis of the ilium bilaterally. She noticed waxing and waning of her eruptions with her menstrual cycle, such that lesions worsen in the luteal phase. Megestrol acetate also induced new eruptions. Examination shows brown staining to all teeth with several missing teeth. She had a marked lower extremity limb length discrepancy with severe restriction of hip abduction. Blood chemistries were grossly normal, including renal function, calcium, uric acid and PTH. Serum phosphorous was elevated at 5.2 (2.3 - 4.5 mg/dL). CT showed bilateral nephrocalcinosis. We instituted treatment with a low phosphorous diet, sevelamer to reduce intestinal phosphate absorption and acetazolamide to increase urinary phosphate excretion. For her pain and functional disability, we recommended continued NSAIDs, physical therapy and social work consultation to facilitate continued access to care. Conclusions: This case uniquely describes hFTC symptom fluctuation with the menstrual cycle, worsening with increased progesterone, suggesting a possible role of gonadal hormones on FGF-23 biology. It also highlights the socioeconomic burdens that can accompany rare bone disease, which become more pronounced as the patient achieves adulthood. Successful transition of care from pediatric to adult endocrinologist, in addition to engaging multi-disciplinary support, is essential in optimizing life-long care in hFTC. Presentation: 6/1/2024

Geochemistry and low-temperature thermochronology of Kunyang phosphate deposit in the Yangtze block and its regional uplift history

The Kunyang phosphate deposit, located on the southwestern margin of the Yangtze Block in southern China, is hosted by the Lower Cambrian Meishucun Formation. The distribution of the deposit is restricted, and the outcrops of its phosphate layer are intermittent, probably owing to subsequent regional uplift and erosion. Therefore, investigating the denudation and uplift history of the deposit can clarify the preservation and distribution of the ore body after its formation, providing insights into the geological evolution of the mining area. Petrographic analysis indicates that collophane is the main ore mineral in the phosphorite, accompanied by dolomite, quartz, and limonite. The bulk-rock geochemical analyses suggest that the formation of phosphorite took place in a marine environment characterized by relative oxidation and high salinity, possibly involving hydrothermal activity during a drier mineralization stage. Apatite fission-track thermochronology, zircon-apatite (U-Th)/He dating, and thermal history modeling demonstrate that the Kunyang phosphate deposit underwent rapid uplift process during the Late Triassic (c. 225–211 Ma) and Eocene (c. 55–30 Ma), respectively. The average cooling rates were 1.05 °C/Myr and 0.93 °C/Myr, respectively, corresponding to average denudation rates of 42 m/Ma and 37 m/Ma. These two episodes of rapid uplift are corresponding to tectonic events on the southwestern margin of the Yangtze Plate during the Indosinian Orogeny, and the collision between the Eurasian and Indian Plates during the Himalayan Orogeny.

Investigation of the microstructural characteristics of laser-cladded Ti6Al4V titanium alloy and its corrosion behavior in simulated body fluid

Laser cladding technology has a wide range of potential industrial applications in the surface strengthening, repair and reuse of orthopedic implants. By employing this technique to conduct same-material surface restoration and enhancement on titanium alloys, it demonstrates significant developmental potential. However, the microstructure of laser additively manufactured titanium alloy differs significantly from that of traditional titanium alloys, which affects its corrosion resistance in human body fluids. To compare the corrosion resistance differences between the cladding layer and the substrate, this study investigates the microstructure of multi-pass laser cladding Ti6Al4V (TC4) titanium alloy and analyzes the corrosion morphology and corrosion products of the cladding layer in simulated body fluids (SBF). By comparing the electrochemical corrosion behavior of laser cladding with that of traditionally manufactured TC4, this research reveals the differences in corrosion resistance between the two titanium alloys. The research demonstrates that the microstructure of cladding primarily consists of prior-β grains and continuous grain boundary α phase, along with a complex basketweave structure composed of fine acicular α phase and lamellar α phase. Additionally, due to the complex thermal cycling process, the acicular α' colonies within the prior-β grains. These features enhance the cladding layer’s resistance to plastic deformation and increase microhardness, though with some uneven distribution. Interestingly, the TC4 cladding layer forms a porous passivation layer after corrosion, primarily composed of a TiO2 passivation film and deposits of hydroxyapatite and other phosphates. Due to the lower β-phase content, finer grains with higher energy states, and a greater proportion of high-angle grain boundaries (HAGBs) in the cladding layer, it exhibits higher electrochemical activity. As a result of these microstructural differences, the corrosion resistance of the TC4 cladding layer in SBF is inferior to that of TC4 manufactured using traditional techniques.

The Effect of SiO&lt;sub&gt;2&lt;/sub&gt; Addition to the Hydroxyapatite/Curcumin Composite Properties

Hydroxyapatite/curcumin composites have been studied as a calcium phosphate cement candidate. In this research, the effects of adding SiO2 to the hydroxyapatite/curcumin composite on the characteristics of the cement, such as the crystal and surface properties, as well as the release behavior of curcumin in Ringer's solution media, were studied. The composite preparation with and without SiO2 was carried out using a Na2HPO4 2.5% solution. The results showed that the addition of 25% SiO2 to the hydroxyapatite/curcumin composite did not change the crystal properties of hydroxyapatite but produced a more homogenous distribution of the ingredients. The behavior of the composite in Ringer's solution also changes, which is proven by the change in the crystal growth direction and Ca/P ratio. Adding SiO2 produced a composite with a platter and larger particles, as well as a higher Ca/P ratio on the surface. The presence of SiO2 inhibited the release of curcumin in which the ratio of HA: curcumin changed from 77.7%:22.3% to 69.6%:30.4% after 5 d of immersion in Ringer's solution. Thus, besides increasing calcium phosphate deposition on the cement surface, SiO2 also prevents curcumin from being released from the composite.

A calcium delivery system fabricated by poly-γ-glutamic acid: Preparation, characterization, and delivery mechanism studies

Calcium has limited bioavailability owing to the formation of calcium phosphate deposits in the gastrointestinal tract. In this study, a polyglutamic acid (PGA)-Ca complex of calcium chelate was prepared using γ-PGA. The binding constant between γ-PGA and calcium was determined to be 6.50 ± 2.47 × 104 mol/L, where 3.6 units of glutamate was capable of binding one Ca2+. The structure of PGA-Ca was characterized, revealing that Ca2+ chelation promoted the aggregation of γ-PGA molecules, disrupting the network structure and forming a mineralized β-sheet-rich structure. In vitro digestion experiments demonstrated that PGA-Ca better maintained the soluble state of Ca2+ in the intestine compared with CaCl2. Cell absorption experiments showed that PGA-Ca exhibited 20% higher permeability through Caco-2 cell monolayers than CaCl2, indicating its higher bioavailability. Notably, PGA-Ca demonstrated improved absorption in the presence of dietary inhibitors, such as oxalate, tannin, and phytate, which compete with Ca2+. Finally, the molecular mechanism underlying the promotion of calcium absorption by PGA-Ca was investigated using RNA sequencing. The results reveal that PGA-Ca enhanced Ca2+ active transport by upregulating CACNA2D3 and downregulating CBARP, while enhancing paracellular Ca2+ transport by downregulating JAM2. This comprehensive study highlights the potential of PGA-Ca as a highly beneficial calcium-delivery system.

Development of hydroxyapatite/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/gelatin composite nanofibers to improve bone‐forming cell proliferation and mineral deposition

AbstractCalcium phosphate hydroxyapatite (HA) was successfully incorporated into poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/gelatin (PHBV/GEL) nanofibers through an electrospinning process in a hexafluoroisopropanol solvent (HFIP). The PHBV/GEL was electrospun and collected using a rotating metallic network to develop highly ordered nonwoven mats. The effects of HA addition on the morphologies of the obtained fibers were investigated using SEM. The average diameter of the fibers ranged around 700–900 nm, depending on the HA content. From a mechanical perspective, the addition of HA nanoparticles showed variations in tensile strength and elastic modulus values. The lowest tensile strength measured for neat PHBV/GEL was 0.37 ± 0.08 MPa with an elastic modulus of 9.45 ± 0.65 MPa, whereas the highest tensile strength reported for 5% HA‐loaded PHBV/GEL mats was 1.1 ± 0.4 MPa with an elastic modulus of 16.9 ± 0.39 MPa. In addition, cell viability, and mineral deposition were also studied using MC3T3‐E1 pre‐osteoblasts. The in vitro experiment results showed that the HA loaded‐PHBV/GEL mats provide optimal conditions for cell growth and osteogenic differentiation of MC3T3‐E1 cells. This study reveals the potential of PHBV/GEL/HA matrices in the development of novel guided bone‐regeneration (GBR) membranes for orthopedic and craniomaxillofacial surgery, by providing favorable structural features for attachment, growth, and differentiation of osteoblast cells.Highlights Simple and cheap electrospinning strategy toward network‐like fibrous mats. Microstructure, mechanical, and biological features were evaluated. Electrospun PHBV/GEL/HA promoted calcium phosphate deposition by MC3T3‐E1 cells.

Land Suitability Analysis for Green Ammonia Unit Implementation in Morocco Using the Geographical Information System–Analytic Hierarchy Process Approach

Morocco contains one of the greatest phosphate deposits and is the second-largest international phosphate fertilizer producer. However, it heavily relies on imported grey ammonia. To reduce this dependency, a paradigm shift is required toward local green ammonia production to strengthen the fertilizer industry. The purpose of the study is to identify the most promising locations in Morocco for hosting a green ammonia unit through a land suitability analysis. This was carried out using multi-criteria decision-making (MCDM) and geographical information systems (GIS). Eight relevant criteria were considered, based on carefully studying the relevant literature and consultation with renewable energy experts and professionals. The land suitability analysis revealed high suitability locations and five sites were selected from the regions of Dakhla, Laayoune, Boujdour, and Tarfaya. These locations were introduced to Hybrid Optimization of Multiple Electric Renewables (HOMER) software 3.16.2 for simulation. The simulation findings showed that the levelized cost of hydrogen (LCOH) ranges from 1.67 USD/kg to 1.82 USD/kg, with the lowest LCOH at Dakhla. The corresponding levelized cost of ammonia (LCOA) ranges from 646 USD/t to 687 USD/t. Dakhla was identified as the location with the lowest LCOA, accounting for 646 USD/t. The outcomes showed a similar trend compared to other studies (Saudi Arabia, Jordan, Iran). Considering improvements in the electrolyzer’s efficiency and cost, a technical and financial sensitivity analysis was conducted, identifying highly promising LCOA in Morocco, reaching 548 USD/t.

Investigating the relationships between radon and the geology of the Sterkfontein cave

Radon, a naturally occurring radioactive gas, has become a subject of increasing interest and concern, particularly in the context of subterranean environments such as caves. This research investigates these dynamics in the Sterkfontein Cave in South Africa, which has formed in the karst geology of the Cradle of Humankind, Gauteng. Additionally, it set out to compile a radon map for the cave, identifying potential radon hotspots. Twenty-four electret ion chambers were placed in the tourist section of the cave and left for a period of 24 h. The radon concentrations were found to be between 53 Bq/m3 and 2770 Bq/m3. Three regions within the cave exhibited elevated radon concentrations, with these occurrences being linked to phosphatic deposits. A subterranean lake also concentrates radon gas in the lower areas of the cave. While the cave's average radon concentration of 427 Bq/m3 exceeds the World Health Organization's (WHO) hazardous level of 300 Bq/m3, occupational exposure remains minimal during a typical cave tour. Consequently, there is no discernible risk during an average tour through the cave.

The Application Progress of Nonthermal Plasma Technology in the Modification of Bone Implant Materials.

With the accelerating trend of global aging, bone damage caused by orthopedic diseases, such as osteoporosis and fractures, has become a shared international event. Traffic accidents, high-altitude falls, and other incidents are increasing daily, and the demand for bone implant treatment is also growing. Although extensive research has been conducted in the past decade to develop medical implants for bone regeneration and healing of body tissues, due to their low biocompatibility, weak bone integration ability, and high postoperative infection rates, pure titanium alloys, such as Ti-6A1-4V and Ti-6A1-7Nb, although widely used in clinical practice, have poor induction of phosphate deposition and wear resistance, and Ti-Zr alloy exhibits a lack of mechanical stability and processing complexity. In contrast, the Ti-Ni alloy exhibits toxicity and low thermal conductivity. Nonthermal plasma (NTP) has aroused widespread interest in synthesizing and modifying implanted materials. More and more researchers are using plasma to modify target catalysts such as changing the dispersion of active sites, adjusting electronic properties, enhancing metal carrier interactions, and changing their morphology. NTP provides an alternative option for catalysts in the modification processes of oxidation, reduction, etching, coating, and doping, especially for materials that cannot tolerate thermodynamic or thermosensitive reactions. This review will focus on applying NTP technology in bone implant material modification and analyze the overall performance of three common types of bone implant materials, including metals, ceramics, and polymers. The challenges faced by NTP material modification are also discussed.

Systematic literature review to inform the EULAR recommendations for the use of imaging in crystal-induced arthropathies in clinical practice

ObjectiveTo summarise current data regarding the use of imaging in crystal-induced arthropathies (CiAs) informing a European Alliance of Associations for Rheumatology task force.MethodsWe performed four systematic searches in Embase, Medline...

Zinc-doped phosphate coatings for enhanced corrosion resistance, antibacterial properties, and biocompatibility of AZ91D Mg alloy

Magnesium and its alloys have been foreseen as promising bone-implant owing to good biocompatibility, high strength, mechanical properties, and biodegradability to replace the conventional bio-metals (Titanium, stainless-steel, Co-Cr alloys) in orthopedic applications. However, high corrosion rate and high degradation rates adversely effects like abrupt evolution of H2 gas and localized alkalization in a physiological environment limit its medical applications. To overcome these issues, phosphate-based surface coating is developed on Mg-alloy to resist the high biodegradation and corrosion rate utilizing magnesium substrate as source of magnesium ion through a single-step hydrothermal process. Controlling the fast corrosion rate and localized alkalization would reduce the antibacterial character of magnesium-based implants therefore, the simple phosphate-based coatings has been induced by doping it with zinc ions due to its physiological tolerance and excellent antibacterial efficacy. The doping of zinc ions may provide a sustained drug-free antibacterial characteristic for potential application in orthopedics. The synthesized phosphate-based coating was characterized using advanced techniques like Scanning Electron Microscopy, X-ray Diffraction, and wettability test, followed by comprehensive electrochemical testing to assess its corrosion behavior. The in vitro immersion test in simulated body fluid (SBF) indicates that deposition of phosphate and zinc doped phosphate coatings reduces the degradation rate consequently minimized the fast dissolution of Mg2+ ions and OH- in physiological environment. Additionally, cytotoxicity and biocompatibility were evaluated using Alamar Blue and live/dead assays on the MC3T3-E1 mouse osteoblast cell line. These assays demonstrated good cell viability, indicating the coatings possess favorable cytocompatibility and support cellular metabolic activity.

Design and Preparation of One-Dimensional Cathode By Electrophoretic Deposition Method for Flexible Knitted Batteries

Rechargeable batteries are highly promising energy storage systems that can convert and store electrical energy. Effective energy storage systems should have high energy density, high power, safety, environmentally friendliness, and long cycle life. To meet the aforementioned objectives, researchers have attempted to use different morphologies of nanomaterials as electrodes to improve the electrochemical performance of batteries. Among the materials available, one-dimensional structures have unique properties over traditional ones and extensive applications in wearable devices due to their flexibility [1]. Flexible batteries have several advantages such as mechanical flexibility, good energy storage capabilities, affordability, and environmental safety [2]. They knitted or sewed into textiles, folded into random forms, and wrapped around body parts like the neck or wrist [3]. However, there is little research that covers Li-ion batteries that have a one-dimensional flexible structure.Achieving simultaneous high electronic/ionic conductivity and electrochemical stability is difficult in a homogeneous single-component electrode material. Consequently, the development of precisely defined functional one-dimensional (1D) hetero-nanostructures that effectively integrate the advantages and address the limitations of various electrochemically active materials becomes critical [1].The proposed methodology involves the electrophoretic deposition of lithium iron phosphate on conductive nickel wire, providing a one-dimensional cathode structure. As an anode, nickel-tin is deposited on nickel wire by electrochemical deposition. The deposition method allows greater precision and control over the deposition of active material on the current collector and also has possible applications on different structures such as 1D and 3D. Also, the electrolyte was obtained by layer-by-layer method, by dipping the cathode and anode, separately, in polymers to coat the cathode material as an electrolyte-separator film. The full cell was assembled and the better results will be presented in the meeting. Acknowledgments This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. АР19679855).

Laser-induced three-dimensional deposition of calcium phosphate on porous Ti6Al4V

This study developed a 3D deposition technology to form calcium phosphate compounds on the top, interior, and bottom surfaces of a porous Ti6Al4V. The deposition was achieved by laser irradiation of a porous Ti6Al4V in a solution containing Ca and P. The effects of the laser power and specimen thickness on the distribution of deposits were investigated. Under laser irradiation, many petal-like deposits formed directly on the top, interior, and bottom surfaces of the porous Ti6Al4V. Increasing the laser power increased the uniformity of the deposits. The deposits fully covered the porous Ti6Al4V when the laser power was 70 %.

Enhanced bioactivity and mechanical properties of silicon-infused titanium oxide coatings formed by micro-arc oxidation on selective laser melted Ti13Nb13Zr alloy

The titanium scaffolds and surface-porous implants are manufactured by fast and cheap additive methods such as selective laser melting (SLM). The obtained irregularity and relative biological inertness of the titanium need proper surface modification. This research is aimed at forming bioactive multicomponent oxide coatings by micro-arc oxidation (MAO) at different process parameters on the selective laser-melted Ti13Zr13Nb alloy. The MAO process was carried out in a base solution containing 0.15 mol/L Ca and 0.1 mol/L GP, with different amounts of metasilicate added under two different applied voltages. Scanning electron microscopy, atomic force microscopy, X-ray electron diffraction spectroscopy, nanomechanical and nano scratch tests, water contact angle measurements, phosphate deposition observed in long-term immersion tests, and biological LDH and MTT assays were performed. The results showed that the coating microstructure, morphology, and properties were significantly dependent on process parameters. In particular, the metasilicate addition and its rising content in the electrolyte resulted in the higher development of the surface followed by better viability of osteoblasts at no necrosis, with no negative change in the other parameters, usually close to those obtained on silicon-free coatings. The obtained results prove that the addition of silicon to the electrolyte at the partial expense of calcium can be favorable for long-term titanium implants made by selective laser melting.

Preparing novel polylactic acid based bone scaffold composites with enhanced calcium phosphate deposition behavior and bioactivity via simple one‐step melt extrusion

AbstractPolylactic acid (PLA) is regarded as the most representative biomedical polymer materials. However, some problems, that is, its big brittleness, high hydrophobicity, and poor bioactivity, limit its application. Here, using poly(butylene adipate‐co‐terephthalate) (PBAT) as toughening agent, and incorporating ethylene diamine tetra(methylene phosphonic acid) (EDTMPA) for the first time with nano‐hydroxyapatite (nHA) as reinforcement filler, series of PLA/PBAT/nHA/EDTMPA as novel bone scaffold composites are successfully prepared via simple one‐step melt extrusion. The chemical composition, microstructures, thermodynamic properties, mechanical properties, hydrophilicity, and bioactivities of PLA/PBAT/nHA/EDTMPA were characterized. The test results show that these developed PLA‐based composites from safe biosources are greatly potential raw materials for bone scaffold because the existence of EDTMPA can chelate with calcium ions to promote calcium phosphate (CaP) deposition on the surface of bone scaffold composites. Especially, when the content of EDTMPA is 6 wt%, the comprehensive performance of the bone scaffold composite is the best. The research results indicate that these developed PLA‐based materials are greatly potential raw materials for bone scaffold composites.

Structure and Properties of Bioactive Titanium Dioxide Surface Layers Produced on NiTi Shape Memory Alloy in Low-Temperature Plasma.

The NiTi alloy, known for its shape memory and superelasticity, is increasingly used in medicine. However, its high nickel content requires enhanced biocompatibility for long-term implants. Low-temperature plasma treatments under glow-discharge conditions can improve surface properties without compromising mechanical integrity. This study explores the surface modification of a NiTi alloy by oxidizing it in low-temperature plasma. We examine the impact of process temperatures and sample preparation (mechanical grinding and polishing) on the structure of the produced titanium oxide layers. Surface properties, including topography, morphology, chemical composition, and bioactivity, were analyzed using TEM, SEM, EDS, and an optical profilometer. Bioactivity was assessed through the deposition of calcium phosphate in simulated body fluid (SBF). The low-temperature plasma oxidization produced titanium dioxide layers (29-55 nm thick) with a predominantly nanocrystalline rutile structure. Layer thickness increased with extended processing time and higher temperatures (up to 390 °C), though the relationship was not linear. Higher temperatures led to thicker layers with more precipitates and inhomogeneities. The oxidized layers showed increased bioactivity after 14 and 30 days in SBF. Low-temperature plasma oxidation produces bioactive titanium oxide layers on NiTi alloys, with a structure and properties that can be tuned through process parameters. This method could enhance the biocompatibility of NiTi alloys for medical implants.

Preparing corrosion-resistant layered double hydroxide coating on magnesium alloy under mild condition

Hydrothermally prepared layered double hydroxide (LDH) coating is unfavorable to large-size magnesium alloy parts. Herein, PO43−- and OH−-intercalated MgAl-LDH coatings with good corrosion resistance and strong adhesion were first prepared under relatively mild conditions. The optimal coating displays an exceptionally low corrosion current density (5.68 nA cm−2), a high charge transfer resistance (831.3 kΩ cm2), and negligible morphological variation without visual corrosion after 15 days of neutral salt spray exposure. The superior long-term protection is attributed to the intelligent release of PO43− and formed phosphate depositions with extremely low solubility product constant to effectively self-repair the micro-defects.