Bioglass Research Articles

A novel rapidly mineralized biphasic calcium phosphate with high acid-resistance stability for long-term treatment of dentin hypersensitivity.

Treating dental hypersensitivity (DH) rapidly and maintaining long-term effectiveness remains challenging. We aimed to address this problem by fabricating a novel rapidly mineralized biphasic calcium phosphate (RMBCP), which could rapidly elicit mineralization to form hydroxyapatite (HA) and perform excellent acid-resistant stability, thus effectively blocking the exposed dental tubules and protecting them from acid attack. RMBCP was firstly synthesized by precisely adjusting the molar ratio of acetic acid and calcium hydroxide and characterized by X-ray diffraction (XRD), X-ray fluorescence microprobe (XRF), Fourier-transform infrared (FTIR) spectrometer, scanning electron microscope (SEM), and transmission electron microscope (TEM). Subsequently, using a commercialized desensitizing agent, 45S5 bioglass (BG), as the control group, the mineralization performance of RMBCP was investigated in simulated body fluid (SBF), Dulbecco's modified eagle medium (DMEM), and even slightly acidic artificial saliva (pH=6.6). Moreover, the biocompatibility of RMBCP was studied. Finally, the tubule occlusion effect and acid-resistant stability of RMBCP were evaluated in vitro and in vivo. The rapid mineralization behavior of RMBCP could easily adhere to the dentin surface and block the dentinal tubules completely in vitro and in vivo within 7days. RMBCP performed high acid-resistant stability to maintain the long-term therapeutic effect of DH treatment. Developing novel bioactive calcium phosphate materials with the ability to trigger mineralization for HA formation rapidly will be an effective strategy for the long-term treatment of dentin hypersensitivity.

Nanostructured 3D bioprinting of PLA with bioglass-CNT scaffolds for osseus tissue graft manufacturing

Bone involvement promoted by aging and accidents has raised interest in biomaterials and biofabrication technologies for bone regeneration purposes. Thus, 3D printing technology has gained prominence in the production of scaffolds due to its versatility in producing complex geometries with interconnected pores. In this work, composite scaffolds of poly (lactic acid) (PLA), bioglass (BG) and carbon nanotubes (CNT) were produced by 3D printing, using hexagonal, honeycomb-like geometry interspersed. The samples were analyzed in terms of chemical structure, crystallinity and morphology using Fourier transform infrared spectroscopy and Raman spectroscopy, X-ray diffraction and scanning electron microscopy, respectively. The thermal stability of the composite was evaluated by thermogravimetry and the mechanical properties by compression tests. The cell viability was determined by Alamar Blue. The results that raman spectroscopy confirmed the interaction of BG in the polymer matrix by new peaks in the spectrum between 1400 and 2600 cm−1 and the presence of the D, G and 2D bands of the CNTs. In terms of compressive strength, PLA scaffolds with 2 mm inner spacing demonstrated higher compressive strength of 14.88 ± 2.35 MPa, while PLA/CNT higher apparent compressive modulus of 0.58 ± 0.36 GPa. In cell viability, statistical tests showed that there was no significant difference between scaffolds with 2 and 4 mm inner spacing.

Cold sintering of bioglass and bioglass/polymer composites

Cold sintering of bioglass and bioglass/polymer composites

The Design and Characterization of New Chitosan, Bioglass and ZnO-Based Coatings on Ti-Zr-Ta-Ag

The starting point of this study is a new alloy with rare metals such as Ta and Zr that has Ag in the composition, proven antibacterial properties. New coatings on Ti-Zr-Ta-Ag capable of improving the alloys’ properties and to be suitable for more applications have yet to be fabricated. New formulations based on chitosan (Ch) and bioglass (BG) were designed as multifunctional coatings to be deposited from suspensions on the mentioned alloy. To make the suspensions used for deposition, several samples were made containing Ch, BG and ZnO in various mass ratios. A number of solutions with different component ratios were produced and analyzed by ζ potential and Dynamic Light Scattering (DLS) to determine the most stable mixture, which was subsequently deposited on the Ti-Zr-Ta-Ag samples. The mixtures and the samples obtained after applying the coating were characterized from a morphological and compositional standpoint using Scanning Electron Microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) and Fourier-transform infrared spectroscopy (FT-IR). Further analyses on the properties of the coating were performed using contact angle and roughness analysis. Zeta potential measurements demonstrated evidence of a good stability of the coatings. The size of the ceramic particles is between 1 and 10 μm. From the SEM, the morphology of all the components from the mixture containing chitosan, bioglass and ZnO are shown to be present on the surface. From the FTIR determination, all the functional groups that appear demonstrated evidence of the presence of BG, ZnO and chitosan. The contact angle values of the coated samples are in the hydrophilic domain but are higher compared to the uncoated alloy values. Such behavior is promising in a potential bioapplication.

Effect of Bioactive Filler Addition on the Mechanical and Biological Properties of Resin-Modified Glass Ionomer.

The maintenance of affected dentin can promote the greater conservation of tooth structure. The development of materials that have properties capable of reducing the demineralizing potential and/or even helping in dental remineralization is important for conservative dentistry. This study aimed to evaluate, in vitro, the alkalizing potential, fluoride as well as calcium ion release ability, antimicrobial activity, and dentin remineralization properties of resin-modified glass ionomer cement (RMGIC) incorporated with a bioactive filler (niobium phosphate (NbG) and bioglass (45S5)). The study samples were grouped into RMGIC, NbG, and 45S5. The materials' alkalizing potential, ability to release calcium as well as fluoride ions, and antimicrobial properties concerning Streptococcus mutans UA159 biofilms were analyzed. The remineralization potential was evaluated using the Knoop microhardness test, which was performed at different depths. The alkalizing and fluoride release potential was higher for the 45S5 group (p < 0.001) over time. An increase in the microhardness of demineralized dentin was observed in the 45S5 and NbG groups (p < 0.001). No differences in biofilm formation were observed between the bioactive materials, although 45S5 exhibited lower biofilm acidogenicity at different time points (p < 0.001) and greater calcium ion release in the microbial environment. A resin-modified glass ionomer cement enriched with bioactive glasses, particularly 45S5, is a promising alternative for the treatment of demineralized dentin.

Fabrication and characterization of additively manufactured CNT-bioglass composite scaffolds coated with cellulose nanowhiskers for bone tissue engineering

During the fabrication of scaffolds for bone regeneration, it is difficult to concurrently achieve bioactivity, mechanical performance, and ease of fabrication. Additionally, implant surface functionalization is a topic of intense research to improve bone-to-implant interaction and augment bone repair. Accordingly, this study reports additively manufactured (AM) 45S5 Bioglass scaffolds reinforced with functionalized multi-walled carbon nanotubes (CNTs) that were dip-coated with cellulose nanowhiskers (CNWs). Carboxymethyl cellulose (CMC) was used as an ink carrier that showed suitable shear thinning behavior. The fabricated scaffolds were characterized using x-ray diffraction (XRD), Fourier transforms infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and energy dispersive x-ray spectroscopy (EDS). 45S5 Bioglass reinforcement with CNTs and coating with CNWs led to an increase in the compressive strength from 20.5 to 27 MPa (∼32% enhancement), while the toughness increased from 2.08 to 3.92 MJ/m3 (∼88% enhancement). Additionally, structural analysis based on microcomputed tomography images showed that the AM-fabricated scaffolds exhibited suitable porosity, pore size, pore throat size, and interconnectivity. Moreover, the coating of the scaffold with CNWs increased the surface roughness, which may aid in bone cell attachment on the scaffold surface. Finally, these scaffolds were found to be bioactive, as revealed by in vitro studies in simulated body fluid (SBF). These results show the potential for efficient fabrication of hybrid scaffolds with controlled structure, bioactivity, and required toughness as well as strength for bone tissue engineering.

Effectiveness of Reinforced 45S5 Bioglass with Yttria-Stabilized Tetragonal Zirconia and Iron in the Regeneration of Rabbit Calvarial Defects

Effectiveness of Reinforced 45S5 Bioglass with Yttria-Stabilized Tetragonal Zirconia and Iron in the Regeneration of Rabbit Calvarial Defects

The Local Release of Teriparatide Incorporated in 45S5 Bioglass Promotes a Beneficial Effect on Osteogenic Cells and Bone Repair in Calvarial Defects in Ovariectomized Rats

With the increase in the population's life expectancy, there has also been an increase in the rate of osteoporosis, which has expanded the search for strategies to regenerate bone tissue. The ultrasonic sonochemical technique was chosen for the functionalization of the 45S5 bioglass. The samples after the sonochemical process were divided into (a) functionalized bioglass (BG) and (b) functionalized bioglass with 10% teriparatide (BGT). Isolated mesenchymal cells (hMSC) from femurs of ovariectomized rats were differentiated into osteoblasts and submitted to in vitro tests. Bilateral ovariectomy (OVX) and sham ovariectomy (Sham) surgeries were performed in fifty-five female Wistar rats. After a period of 60 days, critical bone defects of 5.0 mm were created in the calvaria of these animals. For biomechanical evaluation, critical bone defects of 3.0 mm were performed in the tibias of some of these rats. The groups were divided into the clot (control) group, the BG group, and the BGT group. After the sonochemical process, the samples showed modified chemical topographic and morphological characteristics, indicating that the surface was chemically altered by the functionalization of the particles. The cell environment was conducive to cell adhesion and differentiation, and the BG and BGT groups did not show cytotoxicity. In addition, the experimental groups exhibited characteristics of new bone formation with the presence of bone tissue in both periods, with the BGT group and the OVX group statistically differing from the other groups (p < 0.05) in both periods. Local treatment with the drug teriparatide in ovariectomized animals promoted positive effects on bone tissue, and longitudinal studies should be carried out to provide additional information on the biological performance of the mutual action between the bioglass and the release of the drug teriparatide.

Prediction of Composite Mechanical Properties: Integration of Deep Neural Network Methods and Finite Element Analysis

Extracting the mechanical properties of a composite hydrogel; e.g., bioglass (BG)–collagen (COL), is often difficult due to the complexity of the experimental procedure. BGs could be embedded in the COL and thereby improve the mechanical properties of COL for bone tissue engineering applications. This paper proposed a deep-learning-based approach to extract the mechanical properties of a composite hydrogel directly from the microstructural images. Four datasets of various shapes of BGs (9000 2D images) generated by a finite element analysis showed that the deep neural network (DNN) model could efficiently predict the mechanical properties of the composite hydrogel, including the Young’s modulus and Poisson’s ratio. ResNet and AlexNet architecture were tuned to ensure the excellent performance and high accuracy of the proposed methods with R-values greater than 0.99 and a mean absolute error of the prediction of less than 7%. The results for the full dataset revealed that AlexNet had a better performance than ResNet in predicting the elastic material properties of BGs-COL with R-values of 0.99 and 0.97 compared to 0.97 and 0.96 for the Young’s modulus and Poisson’s ratio, respectively. This work provided bridging methods to combine a finite element analysis and a DNN for applications in diverse fields such as tissue engineering, materials science, and medical engineering.

Physico-biological and in vivo evaluation of irisin loaded 45S5 porous bioglass granules for bone regeneration

In this study, we investigated the physico-biological and in-vivo evaluation of irisin loaded 45S5 bioglass bone graft for enhancing osteoblastic differentiation and bone regeneration in rat femur head defect model. Highly porous structure was obtained in the bioglass by burn-out process with varying the concentration of poly (methyl methacrylate) (PMMA) spheres. 10 % polyvinyl alcohol (PVA) was used as a binder for the sustain releasing of irisin on porous bioglass. Different concentrations of irisin were loaded on the selected bioglass samples and these were further evaluated for the biocompatibility and osteoblastic differentiation properties. The in vitro results demonstrated not only its biocompatibility but also that it stimulated pre-osteoblast differentiation. The in vivo data showed new bone formation as well as expression of osteogenic proteins like alkaline phosphatase (ALP), Runt-related transcription factor 2 (Runx-2), osteopontin (OPN), and collagen-1 (Col-1). Our results support the use of irisin loaded bioglass for the use of early bone regeneration.

Impact of silanization of different bioactive glasses in simplified adhesives on degree of conversion, dentin bonding and collagen remineralization.

To analyze simplified adhesive containing pure or silanized bioglass 45S5 (with calcium) or Sr-45S5 (strontium-substituted) fillers applied on dentin and to evaluate the microtensile bond strength (µTBS), interface nanoleakage, degree of conversion of adhesive, collagen degradation and remineralization. Ambar Universal adhesive (FGM) was doped with 10wt% bioactive glasses to form following groups: Control (no bioglass), 45S5 (conventional bioglass 45S5), Sr-45S5 (Sr-substituted bioglass 45S5), Sil-45S5 (silanized bioglass 45S5) and Sil-Sr-45S5 (silanized bioglass Sr-45S5). Adhesives were applied after dentin acid-etching using phosphoric acid at extracted human molars. Resin-dentin sticks were obtained and tested for µTBS, nanoleakage at 24h or 6 months. Degree of conversion was measured using micro-Raman spectroscopy. Dentin remineralization was assessed by FTIR after 6-month storage in PBS. Hydroxyproline (HYP) release was surveyed by UV-Vis spectroscopy. Statistical analysis was performed using ANOVA and Tukey's test (p<0.05). Regarding µTBS, Sr-45S5 and 45S5 presented higher and stable results (p>0.05). Control (p=0.018) and Sil-Sr-45S5 (p<0.001) showed µTBS reduction after 6-month aging. Sil-Sr-45S5 showed higher HYP release than that obtained in the 45S5 group. Sil-45S5 showed mineral deposition and increase in µTBS (p=0.028) after 6-months. All experimental adhesives exhibited higher degree of conversion compared to Control group, except for 45S5. All adhesives created gap-free interfaces, with very low silver impregnation, except for Sil-Sr-45S5. The incorporation of silanized 45S5 bioglass into the universal adhesive was advantageous in terms of dentin remineralization, bonding performance and adhesive polymerization. Conversely, Sil-Sr-45S5 compromised the µTBS, interface nanoleakage and had a negative impact on HYP outcomes.

A biomaterial-based therapy using a sodium hyaluronate/bioglass composite hydrogel for the treatment of oral submucous fibrosis.

Oral submucous fibrosis (OSF) is a chronic, inflammatory and potentially malignant oral disorder. Its pathophysiology is extremely complex, including excessive collagen deposition, massive inflammatory infiltration, and capillary atrophy. However, the existing clinical treatment methods do not fully take into account all the pathophysiological processes of OSF, so they are generally low effective and have many side effects. In the present study, we developed an injectable sodium hyaluronate/45S5 bioglass composite hydrogel (BG/HA), which significantly relieved mucosal pallor and restricted mouth opening in OSF rats without any obvious side effects. The core mechanism of BG/HA in the treatment of OSF is the release of biologically active silicate ions, which inhibit collagen deposition and inflammation, and promote angiogenesis and epithelial regeneration. Most interestingly, silicate ions can overall regulate the physiological environment of OSF by down-regulating α-smooth muscle actin (α-SMA) and CD68 and up-regulating CD31 expression, as well as regulating the expression of pro-fibrotic factors [transforming growth factor-β1 (TGF-β1), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α) and tissue inhibitors of metalloproteinase-1 (TIMP-1)] and anti-fibrotic factors [interleukin-1β (IL-1β)] in macrophage. In conclusion, our study shows that BG/HA has great potential in the clinical treatment of OSF, which provides an important theoretical basis for the subsequent development of new anti-fibrotic clinical preparations. STATEMENT OF SIGNIFICANCE: Oral submucous fibrosis (OSF) is a chronic, inflammatory and potentially malignant mucosal disease with significant impact on the quality of patients' life. However, the existing clinical treatments have limited efficacy and many side effects. There is an urgent need for development of specific drugs for OSF treatment. In the present study, bioglass (BG) composited with sodium hyaluronate solution (HA) was used to treat OSF in an arecoline-induced rat model. BG/HA can significantly inhibit collagen deposition, regulate inflammatory response, promote angiogenesis and repair damaged mucosal epithelial cells, and thereby mitigate the development of fibrosis in vivo.

3D printed mesoporous bioactive glass, bioglass 45S5, and β-TCP scaffolds for regenerative medicine: A comparative invitro study.

While autografts to date remain the "gold standard" for bone void fillers, synthetic bone grafts have garnered attention due to their favorable advantages such as ability to be tailored in terms of their physical and chemical properties. Bioactive glass (BG), an inorganic material, has the capacity to form a strong bond with bone by forming a bone-like apatite surface, enhancing osteogenesis. Coupled with additive manufacturing (3D printing) it is possible to maximize bone regenerative properties of the BG. The objective of this study was to synthesize and characterize 3D printed mesoporous bioactive glass (MBG), BG 45S5, and compare to β-Tricalcium phosphate (β-TCP) based scaffolds; test cell viability and osteogenic differentiation on human osteoprogenitor cells invitro. MBG, BG 45S5, and β-TCP were fabricated into colloidal gel suspensions, tested with a rheometer, and manufactured into scaffolds using a 3D direct-write micro-printer. The materials were characterized in terms of microstructure and composition with Thermogravimetric Analyzer/Differential Scanning Calorimeter (TGA/DSC), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Micro-Computed Tomography (μ-CT), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Mattauch-Herzog-Inductively Coupled Plasma-Mass Spectrometry (MH-ICP-MS). Scaffolds were tested for cell proliferation and osteogenic differentiation using human osteoprogenitor cells. Osteogenic media was used for differentiation, and immunocytochemistry for osteogenic markers Runx-2, Collagen-I, and Osteocalcin. The cell viability results after 7 days of culture yielded significantly higher (p < 0.05) results in β-TCP scaffolds compared to BG 45S5 and MBG groups. All materials expressed osteogenic markers after 21 days of culture in expansion and osteogenic media.

3D-Printed Polycaprolactone Implants Modified with Bioglass and Zn-Doped Bioglass.

In this work, composite filaments in the form of sticks and 3D-printed scaffolds were investigated as a future component of an osteochondral implant. The first part of the work focused on the development of a filament modified with bioglass (BG) and Zn-doped BG obtained by injection molding. The main outcome was the manufacture of bioactive, strong, and flexible filament sticks of the required length, diameter, and properties. Then, sticks were used for scaffold production. We investigated the effect of bioglass addition on the samples mechanical and biological properties. The samples were analyzed by scanning electron microscopy, optical microscopy, infrared spectroscopy, and microtomography. The effect of bioglass addition on changes in the SBF mineralization process and cell morphology was evaluated. The presence of a spatial microstructure within the scaffolds affects their mechanical properties by reducing them. The tensile strength of the scaffolds compared to filaments was lower by 58-61%. In vitro mineralization experiments showed that apatite formed on scaffolds modified with BG after 7 days of immersion in SBF. Scaffold with Zn-doped BG showed a retarded apatite formation. Innovative 3D-printing filaments containing bioglasses have been successfully applied to print bioactive scaffolds with the surface suitable for cell attachment and proliferation.

Imparting bioactivity to CP−Titanium with sputtered TiBN interlayer and electrophoretically grown bioglass overlay

Surface-modified implant materials with improved physicochemical properties and biocompatibility are vital for determining osseointegration and to enhance bone anchorage. Herein, titanium boron nitride (TiBN) thin films of thickness 3.4 μm were coated as an interlayer on sandblasted Ti plates by confocal D.C. magnetron sputtering using Ti and TiB2 targets. Nanoindentation tests showed a hardness of 27 GPa for the thin film. The bioactivity of the as-prepared coatings was enriched by introducing bioglass (BG), 45S5, overlay via electrophoretic deposition. The nanocrystalline microstructure with lattice parameter 4.2 Å, surface topology and vibration modes/surface chemistry of the coatings were comprehensively studied using microscopic and spectroscopic techniques. Swab inoculation assay, cellular viability assay and hemocompatibility studies revealed that bioglass overlaid thin films exhibited antibacterial property and cytocompatibility with no clot formation. Contact angle measurements showed that 45S5 bioglass-coated substrates were hydrophilic. Biocorrosion studies of the prepared implant materials in simulated body fluid (SBF) revealed the corrosion resistance of bioglass overlaid specimens with the corrosion potential (Ecorr) shifting towards a relatively positive value and the corrosion current density (Icorr) decreasing in the order bare Ti > TiBN >45S5/TiBN coated Ti substrates. Obtained experimental results suggests that the as-prepared 45S5 glass-coated TiBN/Ti plates could be a potential implantable candidate with synergistic cytocompatibility and corrosion resistance.

Preparation and characterization of mesoporous Lanthanum-doped bioactive glass nanoparticles

In this study, novel compositions of mesoporous Bioglass (BG) and Lanthanum-doped BG (La-BG) were prepared using the sol-gel method. Microstructure analysis of the produced composites was performed using XRD, FESEM, FTIR, TGA, and BET techniques. The XRD patterns of BG and La-BG show a good match with the combeite phase. The silicate and phosphate groups in the BG and La-BG lattice were detected in FTIR spectra. The BG particles were spherical, with a surface area of 11.54 m2 /g, a pore volume of 0.02491cc/g, and a pore size of 31.35Å. With the addition of La, the BG structure revealed (i) increased crystallinity of diffraction peaks, (ii) the particles changed from a spherical to a petal-like shape with an expansion in surface area and pore volume, and (iii) increased thermal stability of the BG structure. In conclusion, BG's physiochemical characteristics were greatly enhanced by adding La.

Review on vat photopolymerization additive manufacturing of bioactive ceramic bone scaffolds.

Bone defects frequently occur in clinical settings due to trauma, disease, tumors, and other causes. The clinical use of autologous bones and allograft bone, however, has several limitations, such as limited sources, donor site morbidity, and immunological rejection. Nevertheless, there is newfound hope for regenerating and repairing bone defects through the development and integration of bone tissue engineering scaffold and additive manufacturing (AM) technology, also known as 3D printing. In particular, vat photopolymerization (VPP)-AM of bioactive ceramic bone scaffolds has garnered significant interest from interdisciplinary researchers in recent years. On the one hand, VPP-AM demonstrates clear advantages in printing accuracy and speed compared to other AM and non-AM technologies. On the other hand, bioactive ceramic materials exhibit superior bioactivity, biodegradability, and mechanical properties compared to metals, polymers, and bioinert ceramics, making them one of the most promising biomaterials for developing bone scaffolds. This paper reviews the research progress of VPP-AM of bioactive ceramic bone scaffolds, covering the process principles of various VPP-AM technologies, the performance requirements and preparation process of VPP ceramic slurry, the VPP process of bioactive ceramic bone scaffolds, and the research progress on different material types of VPP bioactive ceramic scaffolds. Firstly, we provide a brief introduction to the process principles and medical applications of various VPP technologies. Secondly, we explore the composition of the VPP ceramic slurry system, discussing the function of various components and their effects on printing quality. Thirdly, we delve into the performance requirements of bone scaffolds and summarize the research progress of VPP bioactive ceramic bone scaffolds of various material types including hydroxyapatite (HA), tricalcium phosphate (TCP), bioglass (BG), etc.; Finally, we discuss the challenges currently faced by VPP-AM bioactive ceramic bone scaffolds and propose possible development directions for the future.

Dilatometric and microstructural study of particle and functionally graded composites based on hydroxyapatite and crystalline bioglass

Hydroxyapatite (HA) and bioglass (BG) ceramics have become of prime importance in bone tissue engineering. Besides the appropriate composition, the microstructure of bone replacement plays a crucial role. In the present work, particle composites and functionally graded material (FGM) based on HA and BG prepared by electrophoretic deposition were thoroughly characterised in terms of the preparation method, sintering process, phase composition and microstructure. The sintering was monitored by high-temperature dilatometry in two directions, the sintering rates were calculated, and the overall sintering process was discussed. The SEM showed the continuous change in the microstructure of FGM with gradual interconnected porosity favourable for bio-applications. The fundamental fractographic analysis proved the crack development in FGM related to the sintering process, and the recommendations for the reduction of the crack development were given. The phase transformations during thermal treatment were analysed using X-ray diffraction analysis and deeply discussed.

Functionally Graded Multilayer Composites Based on Poly(D,L lactide)/Bioactive Fillers Fabricated by a 3D Direct Pellet Printing Multi-Extrusion Process

The aim of the present work was to investigate a 3D manufacturing process dealing with 3D Direct Pellet multi-Extrusion (DPPmE). Throughout this paper, various functionally graded materials (FGM) were obtained with tailored properties for bone regeneration. Therefore, an experimental investigation was performed to gain a better understanding of the structure-processing-properties relationships. A poly(D,l-lactic acid) (PDLLA) matrix and bioglass (BG) or hydroxyapatite (HA) bioactive fillers were chosen to obtain hybrid FGM in comparison to composite references. Different compositions and shape factors (from microspheres to fibers) of these bioactive fillers were used to control the PDLLA matrix degradation. Then, different strategies of DPPmE were used to tailor and tune the desired gradient of properties. Interestingly, good interfaces and adhesion properties were obtained. Subsequently, rheological, size-exclusion chromatography, and porosity measurements corroborated the present findings. Besides, tensile as well as thermomechanical properties showed the advantages of the DPPmE process to fabricate FGM composites with tailored architectures.

In Vitro Evaluation of Pore Size Graded Bone Scaffolds with Different Material Composition.

The demand for biomimetic and biocompatible scaffolds in equivalence of structure and material composition for the regeneration of bone tissue is relevantly high. This article is investigating a novel three-dimensional (3D) printed porous structure called bone bricks with a gradient pore size mimicking the structure of the bone tissue. Poly-ɛ-caprolactone (PCL) combined with ceramics such as hydroxyapatite (HA), β-tricalcium phosphate (TCP), and bioglass 45S5 were successfully mixed using a melt blending method and fabricated with the use of screw-assisted extrusion-based additive manufacturing system. Bone bricks containing the same material concentration (20 wt%) were biologically characterized through proliferation and differentiation tests. Scanning electron microscopy (SEM) was used to investigate the morphology of cells on the surface of bone bricks, whereas energy dispersive X-ray (EDX) spectroscopy was used to investigate the element composition on the surface of the bone bricks. Confocal imaging was used to investigate the number of differentiated cells on the surface of bone bricks. Proliferation results showed that bone bricks containing PCL/HA content are presenting higher proliferation properties, whereas differentiation results showed that bone bricks containing PCL/Bioglass 45S5 are presenting higher differentiation properties. Confocal imaging results showed that bone bricks containing PCL/Bioglass 45S5 are presenting a higher number of differentiated cells on their surface compared with the other material contents.