Tricalcium Phosphate Particles Research Articles

Preparation of Biodegradable Mg/β-TCP Biofunctional Gradient Materials by Friction Stir Processing and Pulse Reverse Current Electrodeposition

Mg alloys, as a new generation of biodegradable bone implant materials, are facing two tremendous challenges of enhancing strength and reducing degradation rate in physiological environment to meet clinical needs. In this study, tricalcium phosphate (β-TCP) particles were dispersed in Mg–2Zn–0.46Y–0.5Nd alloy by friction stir processing (FSP) to produce Mg-based functional gradient materials (Mg/β-TCP FGM). On the surface of Mg/β-TCP FGM, the hydroxyapatite (HA) coating was prepared by electrodeposition. The effects of FSP and electrochemical parameter on the microstructure, microhardness, bonding strength and corrosion performance of the Mg/β-TCP FGM were investigated. After four passes of FSP, a uniform and fine-grained structure was formed in Mg/β-TCP and the microhardness increased from 47.9 to 76.3 HV. Compared to the samples without β-TCP, the bonding strength of the Mg/β-TCP FGM increased from 23.1 ± 0.462 to 26.3 ± 0.526 MPa and the addition of degradable β-TCP contributed to the in situ growth of HA coating. The thickness of HA coating could be dominated by controlling the parameters of electrodeposition. According to the results of immersion tests and electrochemical tests in simulated body fluid, it indicated that the degradation rate of the Mg/β-TCP FGM could be adjusted.

Development of chitosan encapsulated tricalcium phosphate biocomposite for fluoride retention.

The powder form of tricalcium phosphate (TCP) causes the significant pressure drop which limit its application under field conditions. To trounce such technological troubles and to enhance the defluoridation capacity (DC) of TCP, chitosan (CS) encapsulated TCP polymeric composite was prepared by dispersing TCP particles into chitosan polymeric matrix to produce tricalcium phosphate/chitosan (TCPCS) composite which could be made into any desirable form. The synthesized TCPCS composite possesses an enhanced DC of 1034 mgF-/kg than the individual components viz., TCP and chitosan which has got DC of 490 and 52 mgF-/kg respectively. The prepared adsorbents were characterized by FTIR, SEM and EDAX analysis. The various physico-chemical properties such as contact time, solution pH, co-anions and temperature were optimized to get maximum defluoridation. The equilibrium and kinetic experiments were conducted for TCPCS composite toward fluoride removal. The practical applicability of TCPCS composite was examined at field conditions.

Characterization and Photophysical Properties of Tricalcium Phosphates Prepared by Using the Solid-State Reaction Process

Rare-earth-doped phosphors for near ultraviolet excitation are under an extensive research for applications to white-light-emitting diodes. In this study, we prepare red-orange emitting samarium-doped rhombohedral tricalcium phosphate particles by using the solid-state reaction method. The synthesis procedures are reported, the formation of prepared particles is confirmed using X-ray diffraction patterns, and the morphology and the elemental composition are measured using a scanning electron microscope. We also investigate the photophysical properties of trivalent samarium-doped tricalcium phosphate phosphors by taking absorption, excitation, and emission spectra at room temperature. We show that the trivalent samarium-doped tricalcium phosphate phosphors are red-emitting phosphors and have higher efficiency with near ultraviolet excitation. The emission intensity increases very sharply up to a samarium concentration of 2.5 mol% and then decreases as the concentration increases. Therefore, the samarium doping concentration in the tricalcium phosphate phosphor needs to be optimized.

Magnesium-β-Tricalcium Phosphate Composites as a Potential Orthopedic Implant: A Mechanical/Damping/Immersion Perspective

The design and development of novel magnesium-based materials with suitable alloying elements and bio-ceramic reinforcements can act as a possible solution to the ever-increasing demand of high performance bioresorbable orthopedic implant. In the current study, Mg-β-tricalcium phosphate composites are synthesized using the hybrid powder metallurgy technique, followed by hot extrusion. The influence of addition of (0.5, 1, and 1.5) vol % β-tricalcium phosphate on the mechanical, damping, and immersion characteristics of pure magnesium are studied. The addition of β-tricalcium phosphate enhanced the yield strength, ultimate compressive strength, and compressive fracture strain of pure magnesium by about ~34%, ~53%, and ~22%, respectively. Also, Mg 1.5 vol % β-tricalcium phosphate composite exhibited a ~113% enhancement in the damping characteristics when compared to pure magnesium. A superior ~70% reduction in the grain size was observed by the addition of 1.5 vol % β-tricalcium phosphate particles to pure Mg. The response of Mg-β-tricalcium phosphate composites is studied under the influence of chloride environment using Hanks’ balanced salt solution. The dynamic passivation was realized faster for the composite samples as compared to pure Mg, which resulted in decreased corrosion rates with the addition of β-tricalcium phosphate particles to pure Mg.

Adsorption kinetics of ion of Pb2+ using Tricalcium Phosphate particles

One of the heavy metals that can pollute water is Pb2+. The concentration of ion Pb2+ can be removed using the adsorption method. The purpose of this research is to determine the adsorption kinetics model of ions Pb2+ using tricalcium phosphate (TCP) particles with variation of the temperature and adsorbent dosage. Five hundred mililiter Pb2+ solution with of 3 mg/L were added 0,5 gr, 1 gr and 1,5 gr of TCP in a glass beaker and stirred with rate of 300 rpm at a temperature of 30 °C, 40 °C and 50 °C. Pb2+ concentration in solution was analyzed by AAS (Atomic Adsorption Spectroscopy). The results showed that the rate of adsorption increased with the increasing of the temperature and adsorbent dosage. Minimum constant value of adsorption kinetic was 1,720 g/mg.min obtained at temperature of 30 °C and adsorbent dosageof 0,5 gr. The maximum value of adsorption kinetic constant was 9,755 g/mg.min obtained at temperature of 50 °C and adsorbent dosage of 1,5 gr. The appropriate model for adsorption kinetics followed the pseudo second order.

Mesenchymal stem cell seeded, biomimetic 3D printed scaffolds induce complete bridging of femoral critical sized defects.

No current clinical treatments provide an ideal long-term solution for repair of long bone segment defects. Incomplete healing prevents patients from returning to preinjury activity and ultimately requires additional surgery to induce healing. Obtaining autologous graft material is costly, incurs morbidity, requires surgical time, and quality material is finite. In this pilot study, 3D printed biomimetic scaffolds were used to facilitate rapid bone bridging in critical sized defects in a sheep model. An inverse trabecular pattern based on micro-CT scans of sheep trabecular bone was printed in polybutylene terephthalate. Scaffolds were coated with micron-sized tricalcium phosphate particles to induce osteoconductivity. Mesenchymal stem cells (MSCs) were isolated from sheep inguinal and tail fat, in one group of sheep and scaffolds were infiltrated with MSCs in a bioreactor. Controls did not undergo surgery for cell extraction. Scaffolds were implanted into two experimental and two control adult sheep, and followed for either 3 or 6 months. Monthly radiographs and post explant micro-CT scanning demonstrated bone formation on the lateral, anterior, medial, and posterior-medial aspects along the entire length of the defect. Bone formation was absent on the posterior-lateral aspect where a muscle is generally attached to the bone. The 3-month time point showed 15.5% more cortical bone deposition around the scaffold circumference while the 6-month time point showed 40.9% more bone deposition within scaffold pores. Control sheep failed to unite. Serum collagen type-1C-terminus telopeptides (CTX-1) showed time-dependent levels of bone resorption, and calcein labeling demonstrated an increase in bone formation rate in treated animals compared with controls. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 242-252, 2019.

Dicalcium Silicate Induced Proinflammatory Responses through TLR2-Mediated NF-κB and JNK Pathways in the Murine RAW 264.7 Macrophage Cell Line.

Proinflammatory responses are important aspects of the immune response to biomaterials, which may cause peri-implantitis and implant shedding. The purpose of this study was to test the cytotoxicity and proinflammatory effects of dicalcium silicate particles on RAW 264.7 macrophages and to investigate the proinflammatory response mechanism induced by C2S and tricalcium phosphate (TCP). C2S and TCP particles were characterized using scanning electron microscopy (SEM), energy spectrum analysis (EDS) and X-ray diffraction (XRD). Cytotoxicity and apoptosis assays with C2S and TCP in the murine RAW 264.7 cell line were tested using the cell counting kit-8 (CCK-8) assay and flow cytometry (FCM). The detection results showed that C2S and TCP particles had no obvious toxicity in RAW 264.7 cells and did not cause obvious apoptosis, although they both caused an oxidative stress response by producing ROS when the concentrations were at 100 μg/mL. C2S particles are likely to induce a proinflammatory response by inducing high TLR2, TNF-α mRNA, TNF-α proinflammatory cytokine, p-IκB, and p-JNK1 + JNK2 + JNK3 expression levels. When we added siRNA-TLR2-1, a significant reduction was observed. These findings support the theory that C2S particles induce proinflammatory responses through the TLR2-mediated NF-κB and JNK pathways in the murine RAW 264.7 macrophage cell line.

Development of macroporous tricalcium phosphate with hyaluronic acid as the cell carrier as the subcutaneous filler

Abstract The purpose of this study is to develop macroporous TCP (tricalcium phosphate) with irregular shape and the use of HA (hyaluronic acid) gel as the lubricating agent of a composite hydrogel for cell carrier. The porous TCP particle with meteorite shape was made by the solid-state reaction by adding different ratios of the PMMA (Poly(methyl methacrylate)). The subcutaneous filler was made by mixing hyaluronic acid gel with TCP particles and live cells. For the in vitro testing, the mouse fibroblasts cell line L929 was employed for analysis of the toxicity and biocompatibility of the material. The cells were cultured on the material for one to three days followed by the WST-1 (Water soluble tetrazolium) and LDH (Lactate dehydrogenase) analysis. The results of LDH and WST-1 showed that the composite HA/β-TCP was not cytotoxicity. The advantage of this product is the meteorite shaped macroporous TCP particle in the hyaluronic acid gel that could form a linkage channel in the gel. When the fat cell mixed with the composite HA/TCP gel, the fat cells will not be covered with the hyaluronic acid for a long time, and hence the cell will not die of hypoxia or the lack of growth factors provided by the subject’s body fluid. As the proliferation of fat cells progressed, it became a good filler of the injected area.

Sorption thermodynamic and kinetic studies of Lead removal from aqueous solutions by nano Tricalcium phosphate

Nano tricalcium phosphate particles were prepared by a wet method from aqueous solutions and characterized using TEM, XRD, and BET-N2 adsorption measurements. The potential of the synthesized nano tricalcium phosphate particles to remove Pb2+ cations from aqueous solutions was investigated in batch reactor under different experimental condition. The effects of initial concentration, adsorbent dosage, contact time and temperature were studied in batch experiments. The sorption of Pb2+ by nano-TCP increased as the initial concentration of lead ion increased in the medium. Various thermodynamic parameters, such as G°, H° and S° were calculated. Thermodynamics of Pb2+ cation sorption onto nano-TCP system pointed at spontaneous and endothermic nature of the process. The pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models were applied to study the kinetics of the sorption processes. The pseudo-second order kinetic model provided the best correlation (R2 > 0.999) of the used experimental data compared to the pseudo-first order and intraparticle diffusion kinetic models. The maximum Pb2+ adsorbed was found to be 4761.90 mg/g. It was found that the sorption of Pb2+ on nano-TCP was correlated well (R2 = 0.982) with the Langmuir equation as compared to Freundlich and Dubinin–Kaganer–Radushkevich (D-K-R) isotherm equation under the concentration range studied. This study indicated that nano-TCP could be used as an efficient adsorbent for removal of Pb2+ from aqueous solution.

Sorption thermodynamic and kinetic studies of Lead removal from aqueous solutions by nano Tricalcium phosphate

Nano tricalcium phosphate particles were prepared by a wet method from aqueous solutions and characterized using TEM, XRD, and BET-N2 adsorption measurements. The potential of the synthesized nano tricalcium phosphate particles to remove Pb2+ cations from aqueous solutions was investigated in batch reactor under different experimental condition. The effects of initial concentration, adsorbent dosage, contact time and temperature were studied in batch experiments. The sorption of Pb2+ by nano-TCP increased as the initial concentration of lead ion increased in the medium. Various thermodynamic parameters, such as G°, H° and S° were calculated. Thermodynamics of Pb2+ cation sorption onto nano-TCP system pointed at spontaneous and endothermic nature of the process. The pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models were applied to study the kinetics of the sorption processes. The pseudo-second order kinetic model provided the best correlation (R2 > 0.999) of the used experimental data compared to the pseudo-first order and intraparticle diffusion kinetic models. The maximum Pb2+ adsorbed was found to be 4761.90 mg/g. It was found that the sorption of Pb2+ on nano-TCP was correlated well (R2 = 0.982) with the Langmuir equation as compared to Freundlich and Dubinin–Kaganer–Radushkevich (D-K-R) isotherm equation under the concentration range studied. This study indicated that nano-TCP could be used as an efficient adsorbent for removal of Pb2+ from aqueous solution.

Epidermal Growth Factor Tethered to β-Tricalcium Phosphate Bone Scaffolds via a High-Affinity Binding Peptide Enhances Survival of Human Mesenchymal Stem Cells/Multipotent Stromal Cells in an Immune-Competent Parafascial Implantation Assay in Mice.

Stem cells are limited as tissue replacements owing to rapid death induced in the hostile wound environment. It has been found that restricting epidermal growth factor (EGF) receptor signaling to the membrane provides a survival advantage. This report elucidates a method to tether EGF to bone induction material to improve the survival of mesenchymal stem cells/multipotent stromal cells in vivo.

Fabrication of silver/beta‐tricalcium phosphate particle by a simple liquid chemical reduction method

Using beta-tricalcium phosphate (beta-TCP), silver nitrate and glucose as the carrier, silver resource and reducing agent, silver/beta-TCP particle was successfully fabricated by a novel liquid chemical reduction method to overcome the infection problem of beta-TCP. The X-ray diffraction pattern of the as-obtained sample confirmed the existence of metallic silver in the particle. The addition of silver nanoparticle affected the thermal stability of beta-TCP and prevented the transformation from beta-TCP to alpha-TCP. Transmission electron microscopy images and the corresponding calculation result proved the mean size and size distribution of silver nanoparticles in the silver/beta-TCP particle could be controlled by varying the molar ratio between beta-TCP and silver nitrate. Moreover, the mean size and size distribution of silver nanoparticles also could be changed by using different stabilisers. The prepared silver/beta-TCP particle is a potential biomaterial to replace pure beta-TCP particle and utilise for coating material and other applications.

Controlled release of NELL-1 protein from chitosan/hydroxyapatite-modified TCP particles

NEL-like molecule-1 (NELL-1) is a novel osteogenic protein that showing high specificity to osteochondral cells. It was widely used in bone regeneration research by loading onto carriers such as tricalcium phosphate (TCP) particles. However, there has been little research on protein controlled release from this material and its potential application. In this study, TCP was first modified with a hydroxyapatite coating followed by a chitosan coating to prepare chitosan/hydroxyapatite-coated TCP particles (Chi/HA-TCP). The preparation was characterized by SEM, EDX, FTIR, XRD, FM and Zeta potential measurements. The NELL-1 loaded Chi/HA-TCP particles and the release kinetics were investigated in vitro. It was observed that the Chi/HA-TCP particles prepared with the 0.3% (wt/wt) chitosan solution were able to successfully control the release of NELL-1 and maintain a slow, steady release for up to 28 days. Furthermore, more than 78% of the loaded protein⿿s bioactivity was preserved in Chi/HA-TCP particles over the period of the investigation, which was significantly higher than that of the protein released from hydroxyapatite coated TCP (HA-TCP) particles. Collectively, this study suggests that the osteogenic protein NELL-1 showed a sustained release pattern after being encapsulated into the modified Chi/HA-TCP particles, and the NELL-1 integrated composite of Chi/HA-TCP showed a potential to function as a protein delivery carrier and as an improved bone matrix for use in bone regeneration research.

The effect of magnesium alloy wires and tricalcium phosphate particles on apatite mineralization on polylactide-based composites

Biodegradable magnesium alloy wires and tricalcium phosphate nanoparticles were used as a modifying phase of novel polylactide based composite system. The aim of this study was to determine the effect of those two components on apatite mineralization and thus potential bioactivity of the composite material. Studied samples were incubated in Simulated Body Fluid and Phosphate Buffer Saline to simulate biological environment. It was revealed that coexisting modification of polymer matrix with Mg and TCP resulted in formation of apatites with magnesium substitutions that have superior biological properties. Results of the study confirmed that chemical composition of the incubation medium affects composition of the precipitates. Designed multiphase composite can be potentially used for bioactive bone implants.

Effects of Particle Sizes and Natural Polymers on Mechanical Properties of Alpha Tricalcium Phosphate Cements

ABSTRACTCalcium phosphate cements show self-hardening reaction upon mixing with liquids to form calcium-deficient hydroxyapatite (CDHA) or dicalcium phosphate dihydrate. The effects of particle sizes, crystallinities, and natural polymers such as tilapia scale collagen (Col) and hyaluronic acid as a dispersant on the mechanical properties of alpha tricalcium phosphate (TCP) cements mixed with citric acid (CA) as an additive were investigated. Three types of alpha TCP particles were fabricated with spray-dry (SD; 14 μm), freeze-dry (FD; 45 μm), and cold isostatic press (CIP; 134 μm) methods, followed by sintering at 1300°C and ground/crushed. The amounts of Ca dissolution from these particles were in the order of SD > FD > CIP. The CA liquid was added to the powders of SD-FD or SD-CIP, and kneaded under different liquid/powder ratios. The cements containing CIP particles showed lower compressive strength at 22.9 ± 1.5 MPa than those containing FD particles at 28.3 ± 2.5 MPa, even though the apparent densities of the cements containing CIP material was higher. Although the packing density of powders is an important factor on the mechanical properties of cements, the dissolution of Ca ion has a greater impact on the mechanical properties. The addition of Col into the cements increased the mechanical properties at 33.6 ± 2.5 MPa at 1 day to enhance the re-precipitation of CDHA.

Stem cell infiltrated biomimetic inverse trabecular-pattered scaffolds accelerate bone growth during long segment repair in a sheep critical sized defect

Stem cell infiltrated biomimetic inverse trabecular-pattered scaffolds accelerate bone growth during long segment repair in a sheep critical sized defect

Real-time-guided bone regeneration around standardized critical size calvarial defects using bone marrow-derived mesenchymal stem cells and collagen membrane with and without using tricalcium phosphate: an in vivo micro-computed tomographic and histologic experiment in rats.

The aim of the present real time in vivo micro-computed tomography (µCT) and histologic experiment was to assess the efficacy of guided bone regeneration (GBR) around standardized calvarial critical size defects (CSD) using bone marrow-derived mesenchymal stem cells (BMSCs), and collagen membrane (CM) with and without tricalcium phosphate (TCP) graft material. In the calvaria of nine female Sprague-Dawley rats, full-thickness CSD (diameter 4.6 mm) were created under general anesthesia. Treatment-wise, rats were divided into three groups. In group 1, CSD was covered with a resorbable CM; in group 2, BMSCs were filled in CSD and covered with CM; and in group 3, TCP soaked in BMSCs was placed in CSD and covered with CM. All defects were closed using resorbable sutures. Bone volume and bone mineral density of newly formed bone (NFB) and remaining TCP particles and rate of new bone formation was determined at baseline, 2, 4, 6, and 10 weeks using in vivo µCT. At the 10th week, the rats were killed and calvarial segments were assessed histologically. The results showed that the hardness of NFB was similar to that of the native bone in groups 1 and 2 as compared to the NFB in group 3. Likewise, values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2. This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical “lock” between the natural bone and NFB. The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adjunct BMSC therapy.

Inhibition of osteolysis after local administration of osthole in a TCP particles-induced osteolysis model.

Wear debris-induced osteolysis and aseptic loosening are the most frequent late complications of total joint arthroplasty leading to revision of the prosthesis. However, no effective measures for the prevention and treatment of particles-induced osteolysis currently exist. Here, we investigated the efficacy of local administration of osthole on tricalcium phosphate (TCP) particles-induced osteolysis in a murine calvarial model. TCP particles were implanted over the calvaria of ICR mice, and established TCP particles-induced osteolysis model. On days one, four, seven, ten and thirteen post-surgery, osthole (10mg/kg) or phosphate buffer saline (PBS) were subcutaneously injected into the calvaria of TCP particles-implanted or sham-operated mice. Two weeks later, blood, the periosteum and the calvaria were collected and processed for bone turnover markers, pro-inflammatory cytokine, histomorphometric and molecular analysis. Osthole (10mg/kg) markedly prevented TCP particles-induced osteoclastogenesis and bone resorption in a mouse calvarial model. Osthole also inhibited the decrease of serum osteocalcin level and calvarial alkaline phosphatase (ALP) activity, and prevented the increase in the activity of tartrate resistant acid phosphatase (TRAP) and cathepsin K in the mouse calvaria. Furthermore, osthole obviously reduced the release of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) into the periosteum. Western blotting demonstrated TCP particles caused a remarkable endoplasmic reticulum (ER) stress response in the mouse calvaria, which was obviously blocked by osthole treatment. These results suggest that local administration of osthole inhibits TCP particles-induced osteolysis in the mouse calvarial in vivo, which may be mediated by inhibition of the ER stress signaling pathway, and it will be developed as a new drug in the prevention and treatment of destructive diseases caused by prosthetic wear particles.

Prediction of stress-strain curves for TCP/PLLA composites: effect of hydrolysis and strain rate

In this study, effect of hydrolysis in simulated body environment on mechanical behavior of tricalcium phosphate (TCP)/poly(L-lactic acid) (PLLA) composites was analytically characterized. In order to predict stress–strain behavior after hydrolysis, damage of micromechanical analysis proposed by the authors was utilized. In this model, nonlinear behavior in stress–strain relationship was simulated considering interfacial debonding between TCP particle and PLLA matrix. For the purpose of deciding the interfacial strength, such as critical energy release rate, curve fitting was conducted on the result of the composites with 15wt% TCP content at three types of strain rates. Theoretical results on 5 and 10wt% composites using the interfacial strength obtained were in good agreement with experimental results. These results indicated that interfacial strength was dependent only on strain rate and was independent from TCP fraction.

Effect of calcium phosphate-based fillers on the structure and bonding strength of novel gelatin–alginate bioadhesives

Interest in soft and hard tissue adhesives as alternatives for conventional wound closing and bone fixation applications has increased in recent decades as a result of numerous possible advantages such as better comfort and lower cost. A novel bioadhesive based on the natural polymers GA has recently been developed and studied in our laboratory. Hydroxyapatite and tricalcium phosphate are two bioactive ceramics known for their ability to enhance bone regeneration. In the current study, these two bioactive fillers were incorporated into the bioadhesive at concentrations of 0.125, 0.25 and 0.5% w/v, and their effects on the resulting adherence properties to soft and hard tissues were studied. Porcine skin and cortical portions of bovine femurs were used as soft and hard tissue specimens, respectively. The bonding strength was evaluated using an Instron universal testing machine in tensile mode, and the microstructure analysis was based on environmental scanning electron microscope observations. Both bioactive fillers were found to have a reinforcing effect on the adhesives, significantly improving their adhesion to soft tissues in certain concentrations. The best bonding strength results were obtained for 0.25% hydroxyapatite and 0.5% w/v tricalcium phosphate-18.1 ± 4.0 and 15.2 ± 2.6 kPa, respectively, compared with 8.4 ± 2.3 kPa for adhesive with no fillers. The improved adherence is probably related to the stiffness of the insoluble hydroxyapatite and tricalcium phosphate particles which reinforce the adhesive. These particles can clearly be observed in the environmental scanning electron microscope analysis. The potential of these fillers to increase the bonding strength of the adhesive to hard tissues was also demonstrated. Hydroxyapatite and tricalcium phosphate thus improve our new gelatin-alginate bioadhesives, which can be used for both soft and hard tissue adhesive applications.