Fabrication Of Bone Scaffolds Research Articles

Silicon dioxide nanoparticles decorated on graphene oxide nanosheets and their application in poly(l-lactic acid) scaffold

IntroductionThe aggregation of graphene oxide (GO) is considered as main challenge, although GO possesses excellent mechanical properties which arouses widespread attention as reinforcement for polymers. ObjectivesIn this study, silicon dioxide (SiO2) nanoparticles were decorated onto surface of GO nanosheets through in situ growth method for promoting dispersion of GO in poly(l-lactic acid) (PLLA) bone scaffold. MethodsHydroxyl and carboxyl functional groups of GO provided sites for SiO2 nucleation, and SiO2 grew with hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) and finally formed nanoparticles onto surface of GO with covalent bonds. Then, the GO@ SiO2 nanocomposite was blended with PLLA for the fabrication of bone scaffold by selective laser sintering (SLS). ResultThe results indicated that the obtained SiO2 were distributed relatively uniformly on surface of GO under TEOS concentration of 0.10 mol/L (GO@SiO2-10), and the covering of SiO2 on GO could increase interlayer distance of GO nanosheets from 0.799 nm to 0.894 nm, thus reducing van der Waals forces between GO nanosheets and facilitating the dispersion. Tensile and compressive strength of scaffold containing GO@SiO2 hybrids were significantly enhanced, especially for the scaffold containing GO@SiO2-10 hybrids with enhancement of 30.95 % in tensile strength and 66.33 % in compressive strength compared with the scaffold containing GO. Additionally, cell adhesion and fluorescence experiments demonstrated excellent cytocompatibility of the scaffold. ConclusionsThe good dispersion of GO@SiO2 enhances the mechanical properties and cytocompatibility of scaffold, making it a potential candidate for bone tissue engineering applications.

An accurate standardization protocol for heating efficiency determination of 3D printed magnetic bone scaffolds

Last decade, three-dimensional (3D) printing technology has emerged as a useful tool for meticulously fabricated scaffolds with high precision and accuracy, resulting in intricately detailed biomimetic 3D structures. To this end, nowadays, magnetic scaffolds are becoming increasingly attractive in tissue engineering, due to their ability not only to promote bone tissue formation, bone repair, and regeneration, but at the same time allow for nanoscale drug delivery. Although there has been a lot of research effort on the fabrication of bone scaffolds in the last few years, their perspectives as multifunctional magnetic hyperthermia agents remain an open issue. This emerging, uninvestigated research field requires a carefully designed framework to produce reliable results. This work focuses on establishing such a framework by proposing a standardization protocol with certain experimental steps for an accurate evaluation of the heating efficiency of the 3D printed magnetic scaffolds bone phantoms. The specific indexes of specific absorption rate and specific loss power are carefully determined and calculated here to enhance the differences in the heating experimental approaches that have been followed until now between magnetic nanoparticles and magnetic bone scaffolds. Meanwhile, the heating evaluation cases that one can find in magnetic hyperthermia are separately defined and analyzed with their suited experimental protocols. Firstly, 3D printed magnetic scaffolds are designed and fabricated. Secondly, they are evaluated as heating carriers. Agarose is exploited here not only as a tissue mimicking phantom, but also as a heat diffusion medium through the scaffold’s pores. A reliable estimation sequence of the heating efficiency, i.e. the specific absorption rate of the magnetic scaffolds, is introduced, analyzed and discussed in conjunction with the specific loss power, which is the respective quantitative index for evaluating the magnetic nanoparticles’ heating efficacy. Finally, this work proposes how the fabrication procedure of the 3D printed scaffolds can be guided by the magnetic particle hyperthermia literature results, as to increase the scaffolds heating efficiency through printing parameters. Consequently, this work deals with the methodology to create a reproducible and accurate protocol for assessing the heating efficiency of magnetic scaffolds serving as bone implants for deep-seated hyperthermia tumor treatment.

Nano-Hydroxyapatite Bone Scaffolds with Different Porous Structures Processed by Digital Light Processing 3D Printing.

The morphologies and structures of the scaffold have a significant influence on their mechanical and biological properties. In this work, different types of porous structures: Triply periodic minimal surface-Schwarz primitive (P), body-centered cubic, and cubic pore-shaped (CPS) hydroxyapatite scaffolds with ~70% porosity were fabricated through digital light processing (DLP) 3D printing technology. The compressive properties and in vitro cell evaluations such as cell proliferation and attachment morphology of these scaffolds were systematically compared. The results showed that the CPS scaffolds exhibited the highest compressive strength (~22.5 MPa) and modulus (~400 MPa). In addition, the CPS scaffolds also performed the most active cell metabolisms as compared to other two structures, which may account for the larger pore size and smaller curvature of the substrate. This study provides a general guidance for the fabrication and selection of porous bone scaffolds processed by DLP 3D printing.

Revealing the compressive and flow properties of novel bone scaffold structure manufactured by selective laser sintering technique.

Additive manufacturing is revolutionizing the field of medical sciences through its key application in the development of bone scaffolds. During scaffold fabrication, achieving a good level of porosity for enhanced mechanical strength is very challenging. The bone scaffolds should hold both the porosity and load withstanding capacity. In this research, a novel structure was designed with the aim of the evaluation of flexible porosity. A CAD model was generated for the novel structure using specific input parameters, whereas the porosity was controlled by varying the input parameters. Poly Amide (PA 2200) material was used for the fabrication of bone scaffolds, which is a biocompatible material. To fabricate a novel structure for bone scaffolds, a Selective Laser Sintering machine (SLS) was used. The displacement under compression loads was observed using a Universal Testing Machine (UTM). In addition to this, numerical analysis of the components was also carried out. The compressive stiffness found through the analysis enables the verification of the load withstanding capacity of the specific bone scaffold model. The experimental porosity was compared with the theoretical porosity and showed almost 29% to 30% reductions when compared to the theoretical porosity. Structural analysis was carried out using ANSYS by changing the geometry. Computational Fluid Dynamics (CFD) analysis was carried out using ANSYS FLUENT to estimate the blood pressure and Wall Shear Stress (WSS). From the CFD analysis, maximum pressure of 1.799 Pa was observed. Though the porosity was less than 50%, there was not much variation of WSS. The achievement from this study endorses the great potential of the proposed models which can successfully be adapted for the required bone implant applications.

3D-printed hydroxyapatite/gelatin bone scaffolds reinforced with graphene oxide: Optimized fabrication and mechanical characterization

Recently, 3D-printing technology has been widely applied to precisely fabricate tissue-engineered scaffolds with designed shapes and porosity. Especially in bone tissue fabrication, bioceramic-based composites have been commonly proposed because of their favorable osteogenic ability. Among various materials, hydroxyapatite (HA) is frequently adopted to produce bioceramic-based composite scaffolds due to its major features such as osteoconductivity, bioactivity, and low toxicity. However, the intrinsically poor mechanical properties of pristine HA, including low fracture toughness and tensile strength, limit its application in clinical practice, thereby various improvement approaches have been introduced. In the present work, we fabricated graphene oxide (GO)-reinforced HA/gelatin composite scaffolds by extrusion-based 3D-printing under precisely optimized printing parameters. The various printing parameters such as printing temperature, extrusion pressure, and printing velocity were thoroughly investigated and optimized to evaluate the printability of GO-reinforced HA/gelatin composites. Moreover, the overall features of those composites, including physicochemical, rheological, morphological, mechanical, and biological properties were quantitatively analyzed and compared with controls. The overall results indicate that the proper addition of GO can efficiently reinforce the mechanical properties of HA/gelatin composite scaffolds. Specifically, the compressive and flexural strength value of the HA/gelatin composite scaffold was enhanced by 15% and 22% with the 0.5% GO incorporation, respectively. Based on the experimental results, this study suggests the great potential of using GO in the fabrication of composite bone scaffolds with improved mechanical properties for application in bone tissue engineering.

Hydrothermal synthesis of zirconia-based nanocomposite powder reinforced by graphene and its application for bone scaffold with 3D printing

Hydrothermal method is a cheap and green approach for the synthesis of composite powders. In this study, the zirconia (ZrO2)-based nanocomposite powder was reinforced with reduced graphene oxide (ZrO2/RGO) and was synthesized in a one-pot as a precursor for bone scaffold applications. Moreover, for the stimulation of osseointegration in bone scaffolds, Hydroxyapatite (HA) was used in 10 wt%. In this regard, the two types of ZrO2/RGO and ZrO2/RGO/HA precursors were applied for the fabrication of bone scaffolds via 3D printing and finally, the mechanical and biological properties of scaffolds were evaluated. For characterization, the X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), compress strength, and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide as MTT assay protocol were performed. The results demonstrated that the ZrO2/RGO scaffolds with a tolerance of compressive stress of 240.11 MPa depicted better mechanical properties compared with ZrO2/RGO/HA with the compress strength of 141.66 MPa. Moreover, after 7 days of bone scaffolds immersion in simulated body fluid (SBF) the growth of compressive strength began while after 28 days reached 260.15 MPa for ZrO2/RGO and 192.31 for ZrO2/RGO/HA. Finally, the cellular response of the scaffolds indicated the lack of cellular toxicity of the scaffolds during MTT assay.

Three-dimensional (3D), macroporous, elastic, and biodegradable nanocomposite scaffold for in situ bone regeneration: Toward structural, biophysical, and biochemical cues integration

Although bone tissue with remarkable healing capabilities, the rapid and successful bone regeneration continues to present a challenge because that the influence factors for bone healing are multifaceted, especially for massive bone defects. From a cell/material interactions point of view, integrating multiple cues into one biomaterial is considered as a promising approach in the clinical treatment of bone defects thanks to the provided multiple stimuli. Herein, 3D macroporously elastic biodegradable nanocomposite bone scaffolds (PCSG) were successfully developed based on poly(citrate-siloxane) (PCS) hybrid elastomer and reduced graphene oxide (rGO). The PCSG scaffolds combine with structure (3D, largely open and interconnected pore architecture, high porosity), biophysics (high mechanical properties, roughness surface, piezoelectricity property), and biochemistry cues (silica cross-linked network, Si ions release). Experiments demonstrate that the structurally, biophysically, and biochemically biomimetic properties of PCSG scaffolds are beneficial for triggering cell adhesion, proliferation, matrix mineralization , osteogenic differentiation of osteoblasts (MC3T3-E1) in vitro and significantly promoting in situ bone regeneration in a calvarial bone defect model. The effective and simple strategy of multiple cues integration could pave a universally applicable way in development of bone tissue engineering biomaterials with good osteoinductivity and osteoconductivity for large defects repair, and the reported PCSG scaffolds demonstrate the potential clinic application in fields of bone regeneration and 3D culture of cells. • Integrating structure, biophysics, and biochemistry cues into one bone scaffold for in situ bone regeneration. • The fabrication of 3D bone scaffold with largely open and porosity via the facile sol-gel method. • The proposed bone scaffolds with super Young's modulus not only in dry state but in hydrated condition.

Polydopamine modified polycaprolactone powder for fabrication bone scaffold owing intrinsic bioactivity

Polycaprolactone (PCL) has been extensively investigated in the field of bone tissue engineering due to its good biocompatibility, biodegradability and processability. Nevertheless, the lack of bioactivity results in poor osseointegration between artificial implant and host bone tissue, which severely restricts its application for bone regeneration. In this study, PCL powder was first surface functionalized with polydopamine (PDA) coating through oxidative self-polymerization of monomer dopamine, and the PDA modified PCL powder was used for the fabrication of bone scaffold with intrinsic bioactivity via selective laser sintering (SLS). The results suggested that PDA was modified on the PCL powder surface successfully and still remained after laser sintering. The 3D printed scaffold achieved a transition from bioinert to bioactive as evaluated by the formation of apatite on its surface, which was the result of the interaction between the abundant active catechol groups in the introduced PDA and calcium ion from simulated body fluid. Besides, the scaffold provided more hydrophilic surfaces for cell adhesion and growth than the pure PCL scaffold due to the presence of amino and hydroxyl functional group.

Porous tantalum scaffolds: Fabrication, structure, properties, and orthopedic applications

Porous tantalum scaffolds have been developed and clinically utilized as superior implantable biomaterials for orthopedic applications owing to their exceptional corrosion resistance, biocompatibility, osteointegration, and osteoconductivity. Moreover, the biomimetic porous structure and mechanical properties of these scaffolds match those of human bone tissues. Over the past twenty years, the fabrication, structure and properties optimization, and application expansion of porous tantalum scaffolds have been advanced by emerging manufacturing technologies, characterization methodologies, and clinical utilization strategies. Combining our innovative work and over two hundred extant publications, we overview the fabrication, structure, properties, and orthopedic applications of porous tantalum bone scaffolds. Additive manufacturing has become a powerful and versatile technique for fabricating patient-specific and anatomy-matching porous tantalum bone implants with well-designed architectures. Additively manufactured tantalum scaffolds are deemed as new biomaterials for bone repair, as their microstructures and mechanical properties differ from those of bioimplants fabricated by traditional technologies. To understand the safety and effectiveness of these scaffolds for orthopedic applications, we must undertake basic scientific investigations, in vitro studies, pre-clinical studies, and clinical research. Biomechanical studies and porous structure design based on finite element analysis are additional hot topics in tantalum scaffold research.

Bioactivity and Antibacterial Behaviors of Nanostructured Lithium-Doped Hydroxyapatite for Bone Scaffold Application.

The material for bone scaffold replacement should be biocompatible and antibacterial to prevent scaffold-associated infection. We biofunctionalized the hydroxyapatite (HA) properties by doping it with lithium (Li). The HA and 4 Li-doped HA (0.5, 1.0, 2.0, 4.0 wt.%) samples were investigated to find the most suitable Li content for both aspects. The synthesized nanoparticles, by the mechanical alloying method, were cold-pressed uniaxially and then sintered for 2 h at 1250 °C. Characterization using field-emission scanning electron microscopy (FE-SEM) revealed particle sizes in the range of 60 to 120 nm. The XRD analysis proved the formation of HA and Li-doped HA nanoparticles with crystal sizes ranging from 59 to 89 nm. The bioactivity of samples was investigated in simulated body fluid (SBF), and the growth of apatite formed on surfaces was evaluated using SEM and EDS. Cellular behavior was estimated by MG63 osteoblast-like cells. The results of apatite growth and cell analysis showed that 1.0 wt.% Li doping was optimal to maximize the bioactivity of HA. Antibacterial characteristics against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were performed by colony-forming unit (CFU) tests. The results showed that Li in the structure of HA increases its antibacterial properties. HA biofunctionalized by Li doping can be considered a suitable option for the fabrication of bone scaffolds due to its antibacterial and unique bioactivity properties.

Additive Manufacturing of Bone Scaffolds Using PolyJet and Stereolithography Techniques

In this study, the printing capability of two different additive manufacturing (3D printing) techniques, namely PolyJet and micro-stereolithography (µSLA), are investigated regarding the fabrication of bone scaffolds. The 3D-printed scaffold structures are used as supports in replacing and repairing fractured bone tissue. Printed bone scaffolds with complex structures produced using additive manufacturing technology can mimic the mechanical properties of natural human bone, providing lightweight structures with modifiable porosity levels. In this study, 3D scaffold structures are designed with different combinations of architectural parameters. The dimensional accuracy, permeability, and mechanical properties of complex 3D-printed scaffold structures are analyzed to compare the advantages and drawbacks associated with the two techniques. The fluid flow rates through the 3D-printed scaffold structures are measured and Darcy’s law is applied to calculate the experimentally measured permeability. The Kozeny–Carman equation is applied for theoretical calculation of permeability. Compression tests were performed on the printed samples to observe the effects of the printing techniques on the mechanical properties of the 3D-printed scaffold structures. The effect of the printing direction on the mechanical properties of the 3D-printed scaffold structures is also analyzed. The scaffold structures printed with the µSLA printer demonstrate higher permeability and mechanical properties as compared to those printed using the PolyJet technique. It is demonstrated that both the µSLA and PolyJet printing techniques can be used to print 3D scaffold structures with controlled porosity levels, providing permeability in a similar range to human bone.

Additive Fabrication and Characterization of Biomimetic Composite Bone Scaffolds with High Hydroxyapatite Content.

With the increased incidence of bone defects following trauma or diseases in recent years, three-dimensional porous scaffolds fabricated using bioprinting technologies have been widely explored as effective alternatives to conventional bone grafts, which provide cell-friendly microenvironments promoting bone repair and regeneration. However, the limited use of biomaterials poses a significant challenge to the robust and accurate fabrication of bioprinted bone scaffolds that enable effective regeneration of the target tissues. Although bioceramic/polymer composites can provide tunable biomimetic conditions, their effects on the bioprinting process are unclear. Thus, in this study, we fabricated hydroxyapatite (HA)/gelatin composite scaffolds containing large weight fractions of HA using extrusion-based bioprinting, with the aim to provide an adequate biomimetic environment for bone tissue regeneration with compositional and mechanical similarity to the natural bone matrix. The overall features of the bioprinted HA/gelatin composite scaffolds, including rheological, morphological, physicochemical, mechanical, and biological properties, were quantitatively assessed to determine the optimal conditions for both fabrication and therapeutic efficiency. The present results show that the bioprinted bioceramic/hydrogel scaffolds possess excellent shape fidelity; mechanical strength comparable to that of native bone; and enhanced bioactivity in terms of cell proliferation, attachment, and osteogenic differentiation. This study provides a suitable alternative direction for the fabrication of bioceramic/hydrogel-based scaffolds for bone repair based on bioprinting.

Three dimensional printed nanostructure biomaterials for bone tissue engineering.

The suffering from organ dysfunction due to damaged or diseased tissue/bone has been globally on the rise. Current treatment strategies for non-union bone defects include: the use of autografts, allografts, synthetic grafts and free vascularized fibular grafts. Bone tissue engineering has emerged as an alternative for fracture repair to satisfy the current unmet need of bone grafts and to alleviate the problems associated with autografts and allografts. The technology offers the possibility to induce new functional bone regeneration using synergistic combination of functional biomaterials (scaffolds), cells, and growth factors. Bone scaffolds are typically made of porous biodegradable materials that provide the mechanical support during repair and regeneration of damaged or diseased bone. Significant progress has been made towards scaffold materials for structural support, desired osteogenesis and angiogenesis abilities. Thanks for innovative scaffolds fabrication technologies, bioresorbable scaffolds with controlled porosity and tailored properties are possible today. Despite the presence of different bone scaffold fabrication methods, pore size, shape and interconnectivity have not yet been fully controlled in most of the methods. Moreover, scaffolds with tailored porosity for specific defects are still difficult to manufacture. Nevertheless, such scaffolds can be designed and fabricated using three dimensional (3D) printing approaches. 3D printing technology, as an advanced tissue scaffold fabrication method, offers the opportunity to produce complex geometries with distinct advantages. The technology has been used for the production of various types of bodily constructs such as blood vessels, vascular networks, bones, cartilages, exoskeletons, eyeglasses, cell cultures, tissues, organs and novel drug delivery devices. This review focuses on 3D printed scaffolds and their application in bone repair and regeneration. In addition, different classes of biomaterials commonly employed for the fabrication of 3D nano scaffolds for bone tissue engineering application so far are briefly discussed.

Three-Dimensional (3D) printing and bioprinting for orthopaedic biomaterials - A short review

Tissue engineering is a non-conventional approach in creating artificial organs and tissues to heal from bone fracture or organs malfunction by regenerating the damaged tissues. This review paper focuses on bone scaffold fabrication methods using three-dimensional (3D) printing and bioprinting for tissue engineering applications. Various types of biomaterials and fabrication techniques of bone scaffolds aimed for tissue engineering were thoroughly discussed. Suitability of biomaterial and polymer for bone scaffolds is deliberated as part of the review paper. Several biomaterials, mechanical properties and porosity of scaffolds were reviewed to give an in depth understanding on 3D printing and tissue engineering field.

Computer-aided design and additive manufacturing of bone scaffolds for tissue engineering: state of the art

Tissue Engineering (TE) applications are focused on the design and fabrication of computer-aided artificial bone scaffolds with developing Additive Manufacturing (AM) technologies. Three-dimensional (3D) bone scaffold is designed with Computer-Aided Design (CAD) software, it is controlled pore size, and porosity ratio and a systematic production process are followed. In this study, artificial bone scaffold design and manufacturing technologies developed with AM technology have been discussed. The first part of the study is the applications materialized through different design methods such as CAD-based design, image-based design, implicit surface design, Topology Optimization (TO), and space-filling curves, which are used in computer-aided artificial bone scaffold design. Secondly, working principles of various AM technologies such as material extrusion and vat photopolymerization, powder bed fusion, material jetting, and direct writing and advantages and limitations of implementing these technologies in TE are also evaluated. Finally, possible future areas of use of the AM technologies in TE are discussed.

The effect of pore geometry on the mechanical properties of 3D-printed bone scaffold due to compressive loading

Bone substitutes are derived from biological products or synthetic bone substitutes such as ceramics, polymers, metals, and organic or non-organic bone substitutes. Emerging three-dimensional (3D)-printing technologies are enabling the fabrication of bone scaffold with the precise specifications. 3D-printing allows controlled material placement for configuring porous tissue scaffolds with tailored properties such as mechanical stiffness, nutrient transport, and biological growth. Therefore, bone scaffolds with good biological and mechanical properties are needed to be used as a bone substitute in bone tissue engineering. However, inadequate mechanical strength is the major problem in current bone scaffolds fabrication. Therefore, the aim of this study is to design and to simulate the mechanical properties of 3D printed polylactic acid (PLA) bone scaffold with different pore geometries, which are circular, square, hexagonal and triangular. The scaffolds were designed and were simulated by using SolidWorks in determining the mechanical properties. Finite Element Analysis (FEA) of the PLA bone scaffold indicates that scaffolds with hexagonal pore shape has compressive strength of 241.0 MPa, which is matches with the human bone properties.

The Potential of Polyethylene Terephthalate Glycol as Biomaterial for Bone Tissue Engineering.

The search for materials with improved mechanical and biological properties is a major challenge in tissue engineering. This paper investigates, for the first time, the use of Polyethylene Terephthalate Glycol (PETG), a glycol-modified class of Polyethylene Terephthalate (PET), as a potential material for the fabrication of bone scaffolds. PETG scaffolds with a 0/90 lay-dawn pattern and different pore sizes (300, 350 and 450 µm) were produced using a filament-based extrusion additive manufacturing system and mechanically and biologically characterized. The performance of PETG scaffolds with 300 µm of pore size was compared with polycaprolactone (PCL). Results show that PETG scaffolds present significantly higher mechanical properties than PCL scaffolds, providing a biomechanical environment that promotes high cell attachment and proliferation.

Process capability analysis of binder jetting 3D printing process for fabrication of calcium sulphate based porous bone scaffolds

ABSTRACT This study aims at investigating the process capability of a 3D printer for the fabrication of porous bone scaffolds. Initially, a suitable material is identified by optimising process parameters of a 3D printer using a full factorial design approach. Then, dimensional deviation and tolerance grades of the scaffold samples are calculated. Finally, process capability indices are evaluated and the process is recentred. Out of two materials under study, VisiJet PXL Core powder is found to provide better dimensional accuracy. Tolerance grades of the samples are found to be ranged from IT3 to IT10. Maximum dimensional deviation before and after centring the process is found to be 0.47% and 0.44%, respectively. Process capability indices Cp and Cpk are greater than 1 and close to industry benchmark (Cpk ≥1.33). This indicates the process is under statistical control and capable of fabricating porous bone scaffolds suitable for in vitro or in vivo bone tissue engineering applications.

Low-temperature fabrication of calcium deficient hydroxyapatite bone scaffold by optimization of 3D printing conditions

We herein propose a novel low-temperature fabrication process of calcium deficient hydroxyapatite (CDHA) 3D scaffolds for bone tissue regeneration through a combination of material extrusion type 3D printing process and bone cement chemistry. The CDHA scaffolds with high porosity of 70% showed excellent mechanical property of 25 MPa (compressive strength), without any sintering process after 3D printing. By using this method, the final structures do not show size shrinkage, which must be considered in conventional ceramic sintering processes. We could therefore achieve both size- and 3D architecture-controlled porous CDHA scaffolds with high accuracy. In addition, the resulting ceramic cement scaffolds were not brittle and could be machined without chipping or fracturing the scaffold. The complete process takes place at physiological conditions (37 °C, pH=7), and heat sensitive drugs and biomolecules could be directly loaded onto the raw powder and achieve homogeneous distribution throughout the CDHA scaffold. In this study, we discuss various key factors to complete this low-temperature 3D printing fabrication of calcium phosphate, such as the pre-treatment conditions of particles, liquid-to-powder ratio, relationships between strut sizes, infill of structures, setting temperatures and the properties of 3D printed scaffolds. The low-temperature fabrication process of calcium phosphate scaffolds developed in this study has excellent potential for use in bone tissue engineering.

Assessment of the Release Profile of Fibroblast Growth Factor-2-Load Mesoporous Calcium Silicate/Poly-ε-caprolactone 3D Scaffold for Regulate Bone Regeneration

Recent advances in three-dimensional printing technology enable facile and on-demand fabrication of patient-specific bone scaffolds. However, there is still an urgent need for printable biomaterials with osteoinductivity. In the present study, we propose an approach to synthesize fibroblast growth factor-2 loaded-mesoporous calcium silicate nanoparticles. The growth factor loaded-nanoparticles served as fillers of polycaprolactone and then the composite scaffolds with a controlled pore structure were obtained through a fused deposition modeling technique. To evaluate the feasibility of the composite scaffolds in bone tissue engineering, drug release kinetic, bioactivity, cell proliferation, differentiation, and animal study were conducted. Our findings illustrate that utilization of mesoporous calcium silicate allowed the introduction of fibroblast growth factor-2 into the composite scaffolds through a simple soaking process and then gradually released from the scaffold to facilitate proliferation and osteogenesis differentiation of human Wharton’s jelly mesenchymal stem cells. Additionally, the in vivo femur defect experiments also indicate that the co-existence of calcium silicate and fibrous growth factor-2 synergistically accelerated new bone formation. These results demonstrate that the fibroblast growth factor-2-loaded mesoporous calcium silicate nanoparticles/polycaprolactone composite scaffolds may serve as potential bone grafts for facilitating repair of defected bone tissues.