Addition Of β-TCP Research Articles

Experimental toothpastes containing β-TCP nanoparticles functionalized with fluoride and tin to prevent Erosive Tooth Wear

ObjectivesThe present study aimed to synthesize toothpastes containing Beta- TriCalcium Phosphate (β-TCP) nanoparticles, functionalized with fluoride and tin, and test their ability to reduce erosive tooth wear (ETW). MethodsToothpastes were synthesized with the following active ingredients: 1100 ppm of fluoride (as sodium fluoride, F−), 3500 ppm of tin (as stannous chloride, Sn2+), and 800 ppm of β-TCP (Sizes a – 20 nm; and b – 100 nm). Enamel specimens were randomly assigned into the following groups (n = 10): 1. Commercial toothpaste; 2. Placebo; 3 F−; 4. F− + β-TCPa; 5. F− + β-TCPb; 6. F− + Sn2+; 7. F− + Sn2+ + β-TCPa and 8. F− + Sn2+ + β-TCPb. Specimens were subjected to erosion-abrasion cycling. Surface loss (in µm) was measured by optical profilometry. Toothpastes pH and available F− were also assessed. ResultsBrushing with placebo toothpaste resulted in higher surface loss than brushing with F− (p = 0.005) and F− + β-TCPb (p = 0.007); however, there was no difference between F− and F− + β-TCPb (p = 1.00). Commercial toothpaste showed no difference from Placebo (p = 0.279). The groups F−, F− + β-TCPa, F− + β-TCPb, F− + Sn2+, F− + Sn2+ + β-TCPa and F− + Sn2+ + β-TCPb were not different from the commercial toothpaste (p > 0.05). Overall, the addition of β-TCP reduced the amount of available fluoride in the experimental toothpastes. The pH of toothpastes ranged from 4.97 to 6.49. ConclusionsAlthough toothpaste containing β-TCP nanoparticles protected enamel against dental erosion-abrasion, this effect was not superior to the standard fluoride toothpaste (commercial). In addition, the functionalization of β-TCP nanoparticles with fluoride and tin did not enhance their protective effect. Clinical SignificanceAlthough β-TCP nanoparticles have some potential to control Erosive Tooth Wear, their incorporation into an experimental toothpaste appears to have a protective effect that is similar to a commercial fluoride toothpaste.

Effect of various admixtures on selected mechanical properties of medium viscosity bone cements: Part 1 – α/β tricalcium phosphate (TCP)

Every year millions of people around the world suffer from joint and bone diseases and require orthopaedic surgery. Owing to its unique properties such as biocompatibility and ability to bond bones with orthopaedic implants, poly methyl-methacrylate (PMMA) is among the most widely used polymer composites for bone cements in orthopaedic and trauma surgery. On the other hand, this material is characterized by low mechanical properties, which can lead to accelerated implant loosening in aggressive environments, such as the human body. Over the years, researchers have studied PMMA, especially its failure mechanism. Various additives to PMMA have been proposed to enhance the mechanical properties of this material. This study investigated the effect of mixing PMMA with α-TCP (PMMA/α-TCP bone cement composite) and β-TCP (PMMA/β-TCP bone cement composite) on its mechanical properties. The study was conducted on commercially available PMMA (Haraeus Palamed) mixed with α-TCP and β-TCP in different concentrations. TCP has bacteriostatic properties and, as a bone compatible material, it stimulates bone regeneration and bone ingrowth, which highly increases the survival rate of PMMA bonding. However, the addition of particles to PMMA can affect mechanical properties of bone cements. In this study, the effects of 0, 1, 2, 3, 5, 8 and 10% dry mass concentration of TCP in bone cement on the mechanical properties of PMMA were investigated. Samples were subjected to compressive loading. This loading mode is typical of the human body after joint prosthesis implantation. The analysis involved comparing selected mechanical parameters of samples prepared according to manufacturer’s instructions and of samples prepared with the addition of α-TCP and β-TCP. Results demonstrated that the addition of β-TCP, whose crystals are triangular, did not affect the mechanical properties of PMMA. On the other hand, the addition of more than 3% dry mass α-TCP, the inner structure of which is hexagonal, led to a slight yet significant decrease in the compressive strength of PMMA.

467 Enhancing Cell Infiltration and Controlled Growth Factor Release for a Customized 3D-Printed Bone Graft Composite

OBJECTIVES/GOALS: Annually, 1.5 million global patients receive maxillofacial reconstruction. The gold standard, involving bone particulate, lacks reproducibility. To improve this, we have developed a custom 3D-printable, porous cover-core design. This study optimizes the hydrogel core properties and growth factor (GF) release for enhanced bone regeneration. METHODS/STUDY POPULATION: Different ratios of Methacrylated Gelatin (GelMa), Methacrylated Alginate (AlgMa) and tricalcium phosphate (α²-TCP) were combined to optimize cell viability, GF sequestration and mechanical stability. Material characterization was performed using a rheometer to determine the viscoelastic properties of the blends. Release from disks loaded with FGF-containing PLGA microparticles was quantified with an ELISA kit. Furthermore, scanning electron microscopy (SEM) was conducted to quantify hydrogel porosity. In vitro studies were performed using NIH 3T3 murine fibroblasts in Corning Transwells while immunofluorescent, metabolic and osteogenic studies were performed in 96 well plates to investigate cell infiltration, cell adhesion, viability and differentiation, respectively. RESULTS/ANTICIPATED RESULTS: By adjusting the AlgGelMa ratio, we manipulated matrix properties. GelMa possesses excellent durability and cell adhesion due to intrinsic RGD-binding motifs. AlgMa enhanced swelling by 30%, growth factor sequestration by 50% in 24hrs, and matrix storage modulus without increasing the loss modulus which could cause cell migration away from the hydrogel. Varying the AlgGelMa ratio lowered pH, promoted cell infiltration, and reduced fibronectin accumulation. The addition of β-TCP is anticipated to improve cell differentiation towards an osteogenic lineage due to improved elastic modulus, calcium and phosphate ion concentration improving mineral deposition. DISCUSSION/SIGNIFICANCE: These findings suggest through the use of this composite, early cell infiltration can be increased and promoted due to FGF release, leading to increased osteointegration. Our porous cover-core design ensures efficient clot integration and early cell infiltration, enhancing osteointegration through FGF release.

Absorbable calcium and phosphorus bioactive membranes promote bone marrow mesenchymal stem cells osteogenic differentiation for bone regeneration.

Large segmental bone defects are commonly operated with autologous bone grafting, which has limited bone sources and poses additional surgical risks. In this study, we fabricated poly(lactide-co-glycolic acid) (PLGA)/β-tricalcium phosphate (β-TCP) composite membranes by electrostatic spinning and further promoted osteogenesis by regulating the release of β-TCP in the hope of replacing autologous bone grafts in the clinical practice. The addition of β-TCP improved the mechanical strength of PLGA by 2.55 times. Moreover, β-TCP could accelerate the degradation of PLGA and neutralize the negative effects of acidification of the microenvironment caused by PLGA degradation. In vitro experiments revealed that PLGA/TCP10 membranes are biocompatible and the released β-TCP can modulate the activity of osteoblasts by enhancing the calcium ions concentration in the damaged area and regulating the pH of the local microenvironment. Simultaneously, an increase in β-TCP can moderate the lactate content of the local microenvironment, synergistically enhancing osteogenesis by promoting the tube-forming effect of human umbilical vein endothelial cells. Therefore, it is potential to utilize PLGA/TCP bioactive membranes to modulate the microenvironment at the site of bone defects to promote bone regeneration.

Novel 3D-printing bilayer GelMA-based hydrogel containing BP, β-TCP and exosomes for cartilage–bone integrated repair

The integrated repair of cartilage and bone involves the migration and differentiation of cells, which has always been a difficult problem to be solved. We utilize the natural biomaterial gelatin to construct gelatin methacryloyl (GelMA), a hydrogel scaffold with high cell affinity. GelMA is mixed with different components to print a bi-layer porous hydrogel scaffold with different modulus and composition in upper and lower layers through three-dimensional (3D) printing technology. The upper scaffold adds black phosphorus (BP) and human umbilical cord mesenchymal stem cells (hUMSCs) exosomes (exos) in GelMA, which has a relatively lower elastic modulus and is conducive to the differentiation of BMSCs into cartilage. In the lower scaffold, in addition to BP and hUMSCs exos, β-tricalcium phosphate (β-TCP), which has osteoconductive and osteoinductive effects, is added to GelMA. The addition of β-TCP significantly enhances the elastic modulus of the hydrogel scaffold, which is conducive to the osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs). In vitro experiments have confirmed that the bi-layer scaffolds can promote osteogenesis and chondrogenic differentiation respectively. And in the rabbit cartilage–bone injury model, MRI and micro-CT results show that the 3D printed bi-layer GelMA composite scaffold has a repair effect close to normal tissue.

Double network composite scaffolds based on oxidized dextran/gelatin hydrogel and magnesium calcium phosphate cement

Magnesium is the fourth most abundant mineral in the human body and plays a significant role in bone growth and development. However, the precise role of magnesium ions is still considerably debated for bone tissue engineering. Here, the biomimetic composite (GelMCPC-x) scaffolds are produced by adding oxidized dextran/gelatin (OD/Gel) hydrogels and magnesium calcium phosphate cement (MCPC) that consisting of magnesium oxide (MgO), calcium dihydrogen phosphate, and β-tricalcium phosphate. The OD/Gel hydrogel provides the 3D network structure for the biomimetic scaffold. The addition of β-TCP affects the existence type of magnesium ions and MgO content in the biomimetic scaffolds. The MgO hydrated acts as an interacting site between inorganic and organic phases, while the sub-micron MgO particles function as a physical filling, both synergistic improving the compression strength of scaffolds through the chemisorption and physisorption. Our study suggests that the synergy between Gel and MgO actively controls for the nucleation site, and the calcium and magnesium ions provide the growth environment for apatite in vitro. When incorporated with 11 wt% of MgO, the GelMCPC-x composites have high compressive strength (5.3 MPa) and excellent osteogenic differentiation ability. This study provides guidelines for developing magnesium-based biomimetic scaffolds used in non-load-bearing bone.

Mechanical, corrosion and biological behavior of centrifugal casting processed Mg–2Zn–1Mn alloy reinforced with β Tricalciumphosphate (βTCP) for orthopaedic applications

Zinc and manganese were selected to develop magnesium alloys along with the bioactive ceramic β Tricalciumphosphate (βTCP) for biomedical applications fabricated by centrifugal casting. Microstructure, mechanical properties, corrosion properties, and biocompatibility of the Mg–2Zn–1Mn-xβTCP (x = 0, 2.5, 5 wt%) alloys have been investigated by use of an optical microscope, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) analysis, XRD analysis, mechanical testing, cell toxicity and blood hemolysis. A microstructure study has shown that the addition of βTCP significantly reduces the size of the grain. The experimental results of mechanical testing and corrosion studies show that the Mg–2Zn–1Mn-2.5βTCP alloy performs better among the three alloys developed, and the values in Vicker's microhardness, compressive strength, density, and porosity with 47.32HV, 238.22 MPa,1.75 g/cm3 and 2.28% respectively and the values of corrosion potential (Ecorr), corrosion current density (Icorr), linear polarization resistance (Rp) and corrosion rate (mm/year) of the Mg–2Zn–1Mn-2.5 βTCP alloy in the outer and inner layers were found to be −1.46V, 2.71 ×10-5 A/cm2, 1677Ω, 0.62 mm/year and −1.41V, 3.92 ×10-6A/cm2, 4286Ω, 0.20 mm/year respectively. MTT Test and hemolysis experiments revealed that the magnesium alloy had no cell toxicity and good cytocompatibility, however, it produced hemolysis to the blood system. It was proposed that surface modification be used to improve the blood compatibility of the magnesium alloy for use in blood environments.

Fabrication, in vitro and in vivo properties of β-TCP/Zn composites

In recent years, biodegradable Zn-based materials became a hopeful approach for new generation biomedical implants due to their acceptable mechanical performance, moderate biodegradation rate, and good biocompatibility. In this study, the combination of high-energy planetary milling and spark plasma sintering process were employed to fabricate n vol% β-TCP (n = 0, 0.5, 1, 3, 5, 10)/Zn composites with uniform microstructure and high relative density. The microstructure investigation, mechanical performance, degradation behavior, in vitro and in vivo properties of the composites were systematically investigated. As a result, β-TCP nanoparticles were homogeneously dispersed in the whole composites and possessed a good bonding interface with the Zn matrix. The degradation of pure Zn and β-TCP/Zn composites in vitro and vivo is a uniform corrosion process. Enhanced corrosion resistance attributed to the addition of β-TCP with a optimized content. The evaluation of osteogenic differentiation process showed that the addition of β-TCP induced the up-regulated expression of osteogesis-related genes (ALP) in mouse preosteoblasts, thus improving the osteogenic ability. As revealed by animal experiments, six months after implantation of pure Zn and 3TCP/Zn components, the blood biochemical parameters of rats showed no obvious tissue inflammation, indicating excellent in vivo biocompatibility of experimental materials. Histological investigation showed that with prolonged implantation time, the 3TCP/Zn components were more effective than pure Zn in promoting new bone formation. In summary, 3TCP/Zn matrix components developed in the present study should be useful for orthopedic implants.

Beta-tricalcium phosphate enhanced mechanical and biological properties of 3D-printed polyhydroxyalkanoates scaffold for bone tissue engineering

Polyhydroxyalkanoates (PHA) is a naturally degradable polyester with good biocompatibility. However, several disadvantages including poor bioactivity and mechanical properties limit the biomedical application of PHA. To circumvent these drawbacks, PHA needs to be blended with other materials to improve performance. Beta-tricalcium phosphate (β-TCP) has emerged as one of the most promising bone repair materials due to its good biocompatibility, satisfactory mechanical properties, and excellent bone osteoconductivity. In this study, PHA filled with β-TCP in 0 wt%, 5 wt%, 10 wt%, 20 wt%, and 30 wt% of concentrations were produced using a twin-screw extruder. The extruded 3D filaments made with 20% β-TCP exhibited the maximum mechanical properties to manufacture 3D scaffolds for bone tissue engineering. We then prepared the 3D-printed PHA/β-TCP scaffolds by using the fused deposition modeling (FDM) technique. The compressive strength and the shore hardness of the PHA/20%β-TCP scaffold were 36.7 MPa and 81.1 HD. The produced scaffolds presented compressive strength compatible with natural bone. In addition, the scaffolds with a well-controlled design of pore shape and size provided sufficient space for cellular activity. In vitro studies demonstrated that the addition of β-TCP could significantly improve the proliferation, adhesion, and migration of MC3T3-E1 cells in the PHA/β-TCP scaffold. Moreover, the osteogenesis-related genes expression of the PHA/β-TCP scaffold was enhanced compared to the PHA scaffolds. Therefore, the 3D-printed PHA/β-TCP scaffold represents an effective strategy to promote mechanical and biological properties, showing huge potential for bone tissue engineering applications.

Microstructure Evolution and Properties of β-TCP/Mg-Zn-Ca Biocomposite Processed by Hot Extrusion Combined with Multi-Pass ECAP

To further improve the comprehensive performance of Mg-based alloy, hot extrusion combined with multi-pass equal channel angular pressing (ECAP) was applied to process Mg-3 wt%Zn-0.2 wt%Ca alloy and 1 wt%β-TCP/Mg-3 wt%Zn-0.2 wt%Ca biocomposites. The microstructure evolution, mechanical properties, corrosion behavior, and cell biocompatibility of the experimental specimens were systematically investigated. The average grain size of 13.4 ± 0.6 μm in MgZnCa alloy and 9.6 ± 0.3 μm in composites materials can be achieved by six ECAP passes. The uniaxial compressive strength (UCS) of 388.4 ± 7.3 MPa and the strain at failure of 14.3 ± 1.5% were confirmed in MgZnCa alloy, while the UCS of 405.3 ± 7.4 MPa and the strain at failure of 9.8 ± 1.9% were achieved by the addition of β-TCP after six ECAP passes. In spite of different compositions, the minimum corrosion rate of 0.895 mm·Y−1 and 1.117 mm·Y−1 can be achieved by two ECAP passes at 593 K. The cytocompatibility evaluation revealed that the experimental materials processed by six ECAP passes had no significant cytotoxicity to L929 cells, and the addition of β-TCP improved the cytocompatibility.

Microstructure and properties of β-TCP / Zn - 1Mg composites processed by hot extrusion combination of multi-pass ECAP

To further improve the comprehensive service performance of Zn, hot extrusion combined multi-pass equal channel angular pressing route were applied to process Zn-1(wt%)Mg alloy and 1(vol%)β-TCP/Zn-1Mg composites. As-cast cylinders specimens with a diameter of 60 mm were finally processed to the ECAP-processed specimens with the dimensions of 15 mm × 15 mm × 120 mm. The evolution and corresponding mechanism of the microstructure, mechanical properties, corrosion behavior, and biocompatibility of 1β-TCP/Zn-1Mg composites and Zn-1Mg components were systematically investigated. As a result, compared with Zn-1Mg alloy, the grain refinement effect of ECAP was enhanced in the 1β-TCP/Zn-1Mg composites with exact the same ECAP conditions. Among all the experimental specimens, the minimum average grain size of 3.0 ± 0.3 µm was achieved in 1β-TCP/Zn-1Mg composites processed by 8 ECAP passes. With the increase of ECAP processing times, the texture strength increased, and the texture direction changed to be (0 0 0 1) base plane parallel to TD-axis. Consequently, the 1β-TCP/Zn-1Mg composites after 8 passes of the ECAP process exhibited the highest compressive yield strength (CYS) of 288.05 ± 6.87 MPa and an elongation greater than 50%. Moreover, these composites also showed a moderate degradation rate of 0.04496 mm·y−1 in the simulated body fluid solution. The in vitro cytotoxicity and cytocompatibility evaluation revealed that both ECAP-processed Zn-1Mg alloy and 1β-TCP/Zn-1Mg composites showed non-cytotoxicity to MC3T3-E1 cells, and the addition of β-TCP could improve the biocompatibility of the experimental materials. Above all, the combination of hot extrusion and ECAP should be a useful route to obtain biodegradable Zn-based materials with excellent comprehensive service performance as orthopedic implants. The 1β-TCP/Zn-1Mg composites, which were processed by hot extrusion and subsequent 8 passes ECAP, exhibited the highest CYS, moderate degradation rate, and good biocompatibility, should be a promising candidate for the application of bone repair and bone replacement.

Intracanal bonding with therapeutic adhesives and new dentin conditioners

The EDTMP (ethylenediamine-tetra-methylene phosphonate) is a molecule similar to EDTA (ethylenediamine-tetra-acetic acid), but with phosphonates, thereby presenting efficient chelating action and binding adequately to proteins, such as collagen. The objective of this study was to evaluate EDTMP as new etching solution to aid ion-releasing adhesive containing beta-tri-calcium phosphate (β-TCP) fillers used for intrarradicular dentin bonding. Thirty extracted single-rooted human teeth were prepared, and glass-fiber posts were adhesively luted with Scotchbond Multipurpose (SBMP, 3 M) adhesive after etching with 37% phosphoric acid for 15s, 15% EDTA or 15% EDTMP for 120s, and SBMP adhesive incorporated or not with β-TCP. RelyX ARC (3 M) was used as resin cement. The restored roots were cut horizontally in 1 mm-thick slabs and submitted to push-out bond strength test after 24h and 6 months of water storage. Interfacial silver nanoleakage was investigated in scanning electron microscopy. Micro-Raman spectroscopy was employed to track mineralization at the hybrid layer. Data were submitted to two-way ANOVA and Tukey’s test (p<0.05). EDTMP without β-TCP achieved the overall highest bond strength in both storage times. The addition of β-TCP impaired the improvements of EDTMP. The presence of carbonated apatite (peak at 1090 cm -1 ) was found in EDTMP without β-TCP, thereby suggesting remineralization. Little silver impregnation was observed in general across groups. Conclusion : EDTMP could be an optimal alternative as root dentin etchant for luting glass-fiber posts with improvements in dentin bond stability.

Properties improvement of acrylic resin for denture application: effect of single and hybrid types of fillers with different weight loadings

ABSTRACT This research aims to identify the suitable and optimum filler loading to improve the polymethyl methacrylate (PMMA) properties for denture application. Mechanical properties were determined based on the flexural, fracture toughness, hardness and impact strength. The first stage investigated the effect of different weight loadings of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP). The addition of 2 wt-% HA in PMMA composites increased the flexural and fracture toughness when compared with β-TCP composites. The addition of β-TCP in PMMA composites increased the mechanical properties at higher filler loading; 4 and 6 wt-%. The second stage investigated the effect of hybrid fillers; HA/polylactic acid (PLA) microsphere and HA/alumina (Al2O3). HA/PLA microsphere in PMMA showed 5% and 23% improvement on the fracture toughness and impact strength if compared to PMMA/2 wt-% HA. HA/Al2O3 in PMMA showed higher flexural strength. The mechanical properties of a single filler can be further improved by hybrid fillers.

A Biphasic Calcium Phosphate Cement Enhances Dentin Regeneration by Dental Pulp Stem Cells and Promotes Macrophages M2 Phenotype In Vitro.

Calcium phosphate cement (CPC) is promising for bone and dentin repair and regeneration. However, there has been no report of biphasic CPC for inducing dentin regeneration. The aim of this study was to develop a novel biphasic CPC containing β-tricalcium phosphate (β-TCP), and investigate its effects on odontogenic differentiation of human dental pulp stem cells (hDPSCs) and macrophage polarization. New biphasic CPC was formulated with different ratios of β-TCP to an equimolar mixture of tetracalcium phosphate and dicalcium phosphate anhydrous. Mechanical properties, biocompatibility, and odontogenic differentiation induction ability of the cements and the inflammatory reaction to the cements were examined. A series of CPC containing β-TCP were developed. CPC with 20% β-TCP exhibited homogeneity and injectability, an acceptable setting time, and a twofold increase in compressive strength. Significant increases in hDPSCs' alkaline phosphatase activity, mineral deposit, DMP1 and DSPP gene, and protein expressions were obtained for 20% TCP-CPC, compared with traditional CPC (p < 0.01). The addition of β-TCP did not promote macrophage polarization to the proinflammation phenotype. The addition of 10% and 20% β-TCP promoted macrophage polarization to the anti-inflammatory phenotype. In conclusion, a biphasic β-TCP-modified CPC was developed for the first time, demonstrating substantially increased dentin regeneration capability, while promoting macrophages to an anti-inflammation phenotype. The novel biphasic CPC is promising for tooth tissue engineering and dentin regeneration applications. Impact statement Dental pulp exposure from dental caries, wounds, or deep cavity preparation can cause pain and infection, which may lead to root canal treatment or tooth extraction. Maintaining pulp vitality is a major challenge in stomatology. We developed a new injectable β-tricalcium phosphate (β-TCP)-calcium phosphate cement (CPC) for the regeneration of dentin. Compared with traditional CPC, the new CPC +20%TCP possessed good cytocompatibility, acceptable injection force, higher compressive strength (increased by 63%), and greater odontogenic expression and mineral deposits (increased by more than twofolds), while avoiding any proinflammatory drawback. This new biphasic CPC is promising for dental pulp-capping, base, and liner applications to promote dentin regeneration, as well as potentially for bone tissue engineering applications, which warrant further studies.

Effect of Addition of β-TCP on Bioactivity and Mechanical Properties of Biodegradable PLA/β-TCP Composites

Effect of Addition of β-TCP on Bioactivity and Mechanical Properties of Biodegradable PLA/β-TCP Composites

Osteogenic stimulation of human dental pulp stem cells with self-setting biphasic calcium phosphate cement.

Calcium phosphate cement (CPC) is widely used as a repair material for bone defects. However, there is no report on the use of biphasic CPC combined with dental pulp stem cells (DPSCs) for bone tissue engineering. The aim of this study was to construct biphasic CPC and to investigate its effect in the osteogenic stimulation of human DPSCs (hDPSCs) and macrophage polarization. Biphasic CPC was developed by adding different ratios of β-TCP to an equimolar mixture of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA). The biocompatibility, osteogenic capacity, and inflammatory reactions of the cements were examined. Our results show that biphasic CPC containing both HA and β-TCP was successfully fabricated. The addition of β-TCP did not increase necrosis or apoptosis of DPSCs. Significant increases in hDPSC mineral deposition and osteogenic marker (ColI and ALP) expression were observed in 20% TCP-CPC. The addition of β-TCP did not promote macrophage polarization to a proinflammatory phenotype. In conclusion, biphasic CPC with hDPSCs for bone regeneration was developed for the first time; the biphasic CPC combined with hDPSCs is expected to be used for the repair and regeneration of bone.

The effects of β-TCP on mechanical properties, corrosion behavior and biocompatibility of β-TCP/Zn-Mg composites.

Zinc has attracted increasing attention in the field of degradable implant materials due to its suitable degradation rate. To further improve the mechanical properties and biocompatibility of zinc, Zn-1Mg-nvol%β-TCP (n = 0, 1, 3, 5) composites were fabricated for biomedical application by the mechanical stirring combined with ultrasonic assisted casting and hot extrusion technology. The microstructure, mechanical properties and corrosion behavior of these composites were systemically investigated and the composite with the best comprehensive performance were selected for biocompatibility evaluation including L-929 cells cytotoxicity test and SD rat model experiment. Tensile test revealed that Zn-1Mg-1vol%β-TCP composite possessed optimal mechanical properties. The yield strength (YS), ultimate tensile strength (UTS), elongation (σ) and elastic modulus (E) of the as-extruded Zn-1Mg-1vol%β-TCP composite are 250.8 MPa, 330.5 MPa, 11.7% and 125.4 GPa respectively. The immersion tests showed that the corrosion resistance of the composite is slightly decreased with the increase of β-TCP content. In addition, the addition of β-TCP makes the cytocompatibility of the composites better than that of the Zn-1Mg alloy matrix. Various blood biochemical parameters in rat serum samples after implantation showed Zn-1Mg alloy and Zn-1Mg-β-TCP composites has not significant tissue inflammation and showed good biocompatibility.

Load-bearing PTMC-beta tri-calcium phosphate and dexamethasone biphasic composite microsphere scaffolds for bone tissue engineering

In bone tissue engineering, beta-tricalcium phosphate acts as a building block for biomaterials to increases the mechanical properties of biomaterials. Building on our previous scaffold based on PTMC microspheres, we investigated the characteristics of microsphere scaffolds loaded with inorganic particles and the release profile of biphasic drug-loaded microsphere scaffolds. In this investigation, a three-dimensional PTMC/TCP-DEX microsphere scaffold with total porosity of about 50% and pore sizes ranging from 120 to 180 μm was prepared through employing solvent combined with a thermal technique. The addition of β-TCP reduces PTMC microsphere creep and also dramatically improves the mechanical properties of the scaffold (compressive modulus of 18 MPa). Moreover, the PTMC/TCP-DEX scaffold exhibited average porosity (approximately 100 μm) and high water absorption (60%), which are advantageous for release of drug and bioactive substance.

Development of β-TCP-Ti6Al4V structures: Driving cellular response by modulating physical and chemical properties

Load-bearing implants success is strongly dependent on several physical and chemical properties that are known to drive cellular response. In this work, multi-material β-TCP-Ti6Al4V cellular structures were designed to combine Ti6Al4V mechanical properties and β-Tricalcium Phosphate bioactivity, in order to promote bone ingrowth as the bioactive material is being absorbed and replaced by newly formed bone.In this sense, the produced structures were characterized regarding roughness, wettability, β-TCP quantity and quality inside the structures after fabrication and the pH measured during cell culture (as consequence of β-TCP dissolution) and those aspects were correlated with cellular viability, distribution, morphology and proliferation.These structures displayed a hydrophilic behavior and results showed that the addition of β-TCP to these cellular structures led to an alkalization of the medium, aspect that significantly influences the cellular response. Higher impregnation ratios were found more adequate for lowering the media pH and toxicity, and thus enhance cell adhesion and proliferation.

Growth Factors Release From Concentrated Growth Factors: Effect of β-Tricalcium Phosphate Addition.

Platelet concentrates represent a new approach to improve tissue regeneration and can be used alone or together with autogenous bone, recombinant human growth factors, and/or other biomaterials, to enhance tissue regeneration. Among platelet concentrates, concentrated growth factors (CGFs) exhibit an interesting clinical and biotechnological application potential. The aim of this study was to evaluate the in vitro release of 4 growth factors (bone morphogenetic proteins [BMP] -2, BMP-7, transforming growth factor [TGF] -β1, and insulin-like growth factor [IGF] -1) by the enzyme-linked immunosorbent assay (ELISA) technique, in CGFs mixed or not with β-tricalcium phosphate (β-TCP), using or not the Round-up device, at different times. CGFs were obtained from healthy volunteers, mixed or not with β-TCP, using or not the Round-up device. The release of 4 growth factors from these CGFs was then measured at 5 hours, 1, 3, 6, and 8 days, using the ELISA assay. Comparison of the results obtained with those achieved for CGFs alone showed that BMP2 and BMP-7 release, significantly increased in CGFs mixed with Round-up and β-TCP, TGF-β1 release was similar to CGFs alone, whereas IG-1 release was lower compared with CGFs alone. The present data suggest that β-TCP addition to CGF could enhance and improve tissue regeneration, especially bone regeneration, increasing the release of some growth factors that play an important role in osteogenesis.