Papers by Keyword: Bone Tissue Engineering

Abstract: Advanced biocompatible piezoelectric composites have gained significant attention for the development of flexible medical devices and especially related to materials structures that mimic the natural tissue structures. Natural piezoelectricity within the human tissues is reviewed, together with nature-based piezoelectric materials, their advantages and potential for designing the structures for biomedical applications. Electrospun Polyvinylidene fluoride (PVDF) nanofiber matrix, reinforced with silver nanoparticles (AgNPs) is discussed, including specific applications in bone grafts, biosensors and energy harvesting. Processing parameters of the electrospinning fabrication technology have a strong influence on the composite piezoelectricity. Computational models of piezoelectric composites have become a major support in material design for the real case applications. Existing approaches to the numerical modeling of piezoelectric composites have been shortly reviewed toward a recent trend of AI supported modeling for providing effective composite properties, prediction and optimization of material properties and behavior, such as the output voltage and power. Polymer-based biomedical piezoelectric composites have shown excellent results in laboratory research from aspects of their flexibility and possibility to tailor their electro-mechanical properties. However, output piezoelectric signals are still much lower than in the case of traditional ceramic-based materials, including challenges related to the stability of the electric signal, signal noise, piezoelectric impedance and durability of composites with nature-based reinforcements. Future directions in custom composite design, including currently available computational models to enable more rapid development of biomedical piezoelectrics are elaborated at the end.

Abstract: Carbonated hydroxyapatite (CHA), with a chemical composition close to the mineral found in human bone, represented higher solubility than stoichiometric hydroxyapatite (HA). Therefore, the B-type CHA is commonly used for bone tissue engineering. This study fabricated B-type CHA using Indonesian eggshells from chicken, organic chicken, and duck because of the high calcium carbonate (CaCO₃) content (94%). A co-precipitation method was used for synthesizing CHA. The physicochemical properties of the CHA were characterized using Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), X-Ray Diffractometer (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). Based on FTIR results for CHA, the stretching functional groups of B-type CO₃ were detected at 1452-1453 cm^-1, 1417-1418 cm^-1, and 873-874 cm^-1, which indicated the formation of B-type CHA. Meanwhile, CHA from organic chicken eggshells had low crystalline properties and the best morphology due to a more homogeneous and uniform agglomeration. More specifically, CHA based on organic chicken eggshells has a Ca/P molar ratio following natural human bone, which is 1.71. Therefore, all B-type CHA samples are candidates in bioceramic materials for bone tissue engineering applications.

Abstract: This study constructed poly (vinyl alcohol)/ biphasic-calcium phosphate (PVA/ BCP) composite scaffolds. The biphasic-calcium phosphate (BCP) was incorporated in 0, 5, 10, and 25 wt%; BP0, BP1, BP2, and BP3, respectively. The surface morphology was done with a scanning electron microscope (SEM) to observe the porosity and the pore size and distribution of fabricated samples. The Fourier Transform Infrared spectroscopy (FTIR), and some physical properties such as porosity, density, swelling ratio, flexural strength, impact strength, and compression strength were also investigated. The biodegradation and bioactivity were also tested. The SEM results showed that the pores increased and became more regular and interconnected to each other with the increasing addition of BCP. The density decreased with the addition of BCP, while the porosity and mechanical properties increased with additives. The sample of BP3 has a high porosity (67%) and high impact strength (11.9 MPa). The high porosity is favorable for bone implants, and the mechanical strength must also be considered. The bio tests show that the biodegradation became regular by adding the BCP powder, which leads to ease of controlling the gradual degradation and the samples are bioactive for bone tissue. Keywords: Bone Tissue Engineering, PVA, Biphasic-Calcium Phosphate, Porosity, Mechanical properties

Abstract: There are many requirements for biomaterials used in the applications of bone tissue engineering, besides their biocompatibility, they should exhibit acceptable mechanical properties to mimic bone properties. Many research areas in bioactive materials for bone tissue engineering focused on producing new bioactive glass and ceramic compositions containing a trace of inorganic elements (such as Mg, Sr, Cu, Zn) to combine the mechanical properties and bioactivity. In the present study bioglass-MgO composite material has been used to produce Diopside (CaMgSi₂O₆) by the sintering process. The compact samples were made from a mixture powder of (7, 15)wt% MgO and binary bioglass 70Si-30Ca sintered at 1100 ᵒC for 2 hr. The XRD results confirmed the presence of diopside and wollastonite CaSiO₃ in the case of using 7wt.% MgO while the structure was completely diopside at 15 Wt.% MgO. Physical properties, compressive strength, and hardness were investigated, as well as biodegradation behavior and bioactivity in human saliva were inspected. The results confirmed improving the mechanical properties along with increasing MgO as well as proved the ability to form hydroxyapatite on the surface when exposed to human saliva. These findings demonstrated the positive role of MgO in the mechanical properties of 70Si-30Ca bioactive glass besides producing diopside as a good candidate for hard tissue engineering.

Abstract: Recently investigated photocurable, biocompatible plant resin on tissue engineering to provide the scaffold with structural support and mechanical properties. A novel method had been used here to build our scaffold by combined the traditional three-dimensional fused deposition modeling (FDM) printing and injected the structural scaffold after fabrication with plant-based resin. The materials used are polymers a synthesized one polylactic acid and soybean oil epoxidized acrylate. The addition of soybean plant-based resin improves the adhesion and proliferation of the PLA scaffold while also providing structural support to the fabricated scaffold. The purpose of the study made optimization of printing parameters and compared different printing scaffolds to select the perfect one with preferred mechanical properties. Two designs are built (cubic design and cylinder design) to make a comparison of mechanical properties between the two designs. The novel method was used through injected soybean oil resin into the PLA scaffold by avoiding any heat and temperature rise of the resin. In the traditional method, the resin is printed using an SLA printer which exposed the resin to heating before printing, this will affect the properties of the final model in our technique temperature will eliminate by direct inject the plant-based resin into the PLA scaffold and then photocuring with ultraviolet curing device for 30 min at 405nm. Finally, the results demonstrate that after injecting PLA scaffold with soybean oil resin, the mechanical properties of the scaffold improve; additionally, the results show that the cylindrical design has more promising mechanical properties than the cubic design.

Abstract: Human bone has a complex geometry, varying its structure and composition. Additive manufacturing processes, such as selective laser sintering (SLS), can produce bone scaffolds with a wide range of biomaterials. Through SLS a complex structure with highly interconnected porous can be fabricated from a combination of materials. Composites made from biopolymers and bioceramics have shown promising results for bone regeneration, although some properties still must be enhanced. Finding suitable processing parameters is mandatory to achieve required final properties. This review paper is focused on polymer/ceramics using SLS machines in the last 10 years.

Abstract: The ceramics in the system CaO–MgO–SiO₂ has recently attracted a great deal of attention because they display a good in vitro bioactivity and have potential use as bone implants. Biphasic calcium-magnesium-silicate ceramics were prepared by a sol-gel method. The dried gel with chemical composition 3CaO.MgO.2SiO₂ was thermally treated at 1200 °C for 2 hrs. The structural behavior of the synthesized ceramics was examined by means of X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Merwinite crystalline phase and akermanite phase were recognized. Then, porous akermanite/merwinite scaffolds were prepared to utilize polymer sponge method and evaluated by employing SEM. Furthermore, bone marrow stromal cells (BMSC) adhesion and proliferation on the scaffolds were evaluated by MTT assay test. Differentiation of the cells was assessed by measuring alkaline phosphatase (ALP) activity. The results demonstrated that BMSC adhered and spread well on akermanite scaffolds and proliferated with the increase in the culture time, and the differentiation rate of osteoblasts on scaffolds was comparable to that on blank culture plate control. Thus, the obtained results presented that the akermanite/merwinite scaffolds deserve attention for bone tissue engineering applications.

Abstract: Three-dimensional (3D) porous carbonated hydroxyapatite (CHA) scaffolds were successfully prepared using polyurethane (PU) replication technique. Two sets of porous scaffolds were prepared using as-synthesized and as-calcined CHA powder as the main component of the slurry. The effect of the condition of starting material was investigated in terms of structure, phase purity, crystallinity and morphology of the fabricated porous scaffolds. Regardless of the condition of starting material used, the porous scaffolds fabricated was single phase B-type CHA and free of secondary phases. Interestingly, scaffolds made of as-calcined CHA powder (SC scaffolds) showed a smoother surface and more solidified struts when compared to as-synthesized CHA powder (SA scaffolds). This is attributed to the state of semi-crystalline phase of the as-calcined powder being amorphous phase. SC scaffold was found to be better scaffold with respect to handling, compaction strength and microstructure with better strut properties.

Abstract: Three-dimensional (3D) carbonated hydroxyapatite (CHA) porous scaffolds were successfully fabricated via polyurethane (PU) replication technique. Two sets of porous CHA scaffolds were prepared using: 1) as-synthesized CHA slurry (SCHA) and (2) as-synthesized CHA slurry with the addition of sintering aid, magnesium hydroxide (SCHA+Mg (OH)₂). The aim of this study was to investigate the influences of the addition of sintering aid in the fabrication of porous CHA scaffolds in terms of phase purity, crystallinity, architecture, and mechanical properties. Result suggested that both of the fabricated porous scaffolds remained as single phase B-type CHA and free of secondary phases. Interestingly, the use of Mg (OH)₂ as sintering aid led to better internal architecture resulted in smoother surface and less micro-cracks/pores formation on the struts since the struts was found to be more densified as compared to SCHA scaffolds. In terms of mechanical properties, SCHA+ Mg (OH)₂ scaffolds showed higher compressive strength, indicating that the use of Mg (OH)₂ had successfully reduced the sintering temperature and improve the densification of porous scaffolds. Thus, SCHA+ Mg (OH)₂ scaffolds was found to be a better choice of scaffold with respect to its handling, compaction strength and architecture with improve strut properties.

Abstract: Bone tissue engineering is an alternative approach to generate bone using biomaterials and cells. Hydroxyapatite (HA) has good biocompatibility, osteoinductivity, and osteoconductivity. However, it has limited utility due to poor mechanical properties and slow degradation rate. To improve mechanical properties and to modify degradation profile, hydroxyapatite was tethered in chitosan (CS) and carboxymethyl cellulose (CMC) complex. Gelatin was incorporated to promote cell attachment and polyvinyl alcohol (PVA) was used to improve mechanical strength of this scaffold. The physico-mechanical and biological properties of these scaffolds were investigated. Fourier transform infrared (FTIR) analysis and X-ray diffraction (XRD) showed the incorporation of hydroxyapatite in polymer matrix. The scaffolds had density, compressive strength, and Young’s modulus in the range of 0.24-0.30 g/cm³, 0.028-0.035 MPa, 0.178-0.560 MPa, respectively. The scaffolds had porosity of 69-91 percent. Higher content of PVA decreased porosity of scaffolds. Scanning electron microscope showed porous microstructure with pore size in the range of 60-183 μm. In vitro test on MC3T3-E1 preosteoblast cells showed negligible cytotoxicity of scaffolds. The data suggested that HA/CS/CMC/gelatin/PVA scaffold has potential applications in bone tissue engineering.