The Mineralization of Various 3D-Printed PCL Composites (original) (raw)
A biomimetic approach to evaluate mineralization of bioactive glass-loaded resin composites
Journal of Prosthodontic Research, 2022
Bioactive glasses (BAG), first melt-derived in the late 1960s by Larry Hench, obtained good clinical results in dentistry, due to their properties of good bioactivity, when used to treat bone defects[1]. The composition of this bioactive glass was 45 wt% SiO 2 , 24.5 wt% Na 2 O, 24.5 wt% CaO, and 6 wt% P 2 O 5 , which was later termed as 45S5 or Bioglass®. Recently, various researchers have incorporated BAG into experimental[2-5] and commercial dental resin composite materials[6]. The release of calcium and phosphate ions was used as a means to assist with prevention of demineralization of dentine from an initial caries attack. Furthermore, BAG-containing resin composites can reduce bacterial penetration into marginal gaps due to their ability to increase local pH, precipitate apatite on the surface, or in this case within the gap[7]. In addition, a novel design of resin composite-based implant containing bioactive glass has successfully been used for many years[8,9]. The fiber-reinforced composite implants loaded with bioactive glass were supported to enhance biological bone repair and the formation of vascularized structures, in addition to providing improved antimicrobial properties for implants. Chemically speaking, this type of "bioactive" action is a mineralization reaction. At the beginning, a silica-rich layer with Si-OH groups forms on the surface by the exchange of Na + and Ca 2+ ions from the glass with surrounding H + ions, which increases surrounding pH. Then, Ca 2+ and PO 4 3− from surrounding solution forms amorphous calcium phosphate (ACP, Ca x (PO 4) y •nH 2 O)[10] on the surface, which is transformed into octacalcium phosphate (OCP, Ca 8 (HPO 4) 2 (PO 4) 4 •5H 2 O) [10] and finally evolves into nanocrystalline carbonated hydroxyapatite (CHA, Ca 10−x (PO 4) 6−x (CO 3) x (OH) 2−x−2y (CO 3) y) not hydroxyapatite (HA, Ca 10 (PO 4) 6 (OH) 2) in human body as bone or tooth enamel[11,12].
Structural Evolution of PCL during Melt Extrusion 3D Printing
Macromolecular Materials and Engineering
Screw-assisted material extrusion technique has been developed for tissue engineering applications to produce scaffolds with well-defined multi-scale microstructural features and tailorable mechanical properties. In this study, in situ timeresolved synchrotron diffraction was employed to probe extrusion-based 3D printing of polycaprolactone (PCL) filaments. Time-resolved X-ray diffraction measurements revealed the progress of overall crystalline structural evolution of PCL during 3D printing. Particularly, in situ experimental observations provide strong evidence for the development of strong directionality of PCL crystals during the extrusion driven process. Results also show the evidence for the realization of anisotropic structural features through the melt extrusion-based 3D printing which is a key development towards mimicking the anisotropic properties and hierarchical structures of biological materials in nature, such as human tissues.
Polymers, 2022
The most common three-dimensional (3D) printing method is material extrusion, where a pre-made filament is deposited layer-by-layer. In recent years, low-cost polycaprolactone (PCL) material has increasingly been used in 3D printing, exhibiting a sufficiently high quality for consideration in cranio-maxillofacial reconstructions. To increase osteoconductivity, prefabricated filaments for bone repair based on PCL can be supplemented with hydroxyapatite (HA). However, few reports on PCL/HA composite filaments for material extrusion applications have been documented. In this study, solvent-free fabrication for PCL/HA composite filaments (HA 0%, 5%, 10%, 15%, 20%, and 25% weight/weight PCL) was addressed, and parameters for scaffold fabrication in a desktop 3D printer were confirmed. Filaments and scaffold fabrication temperatures rose with increased HA content. The pore size and porosity of the six groups’ scaffolds were similar to each other, and all had highly interconnected structur...
Development and performance analysis of PCL/silica nanocomposites for bone regeneration
Journal of Materials Science: Materials in Medicine, 2010
In the present article, several developments of biocomposites containing silica nanoparticles intended for bone regeneration are reported. Nanocomposites of poly(ecaprolactone) (PCL) and silica, in which either the silica nanoparticles or the PCL have been modified in order to improve interfacial adhesion through chemical graft between the phases are hereafter described. The composites are characterized with respect to their chemical-physical and mechanical properties. Their biocompatibility and capacity to induce the osteoblastic phenotype in human bone marrow mesenchymal stem cells have been assessed.
Natural and Synthetic Polymer Fillers for Applications in 3D Printing—FDM Technology Area
Solids
This publication summarises the current state of knowledge and technology on the possibilities and limitations of using mineral and synthetic fillers in the field of 3D printing of thermoplastics. FDM technology can be perceived as a miniaturised variation of conventional extrusion processing (a microextrusion process). However, scaling the process down has an undoubtful drawback of significantly reducing the extrudate diameter (often by a factor of ≈20–30). Therefore, the results produced under conventional extrusion processing cannot be simply translated to processes run with the application of FDM technology. With that in mind, discussing the latest findings in composite materials preparation and application in FDM 3D printing was necessary.
Applied Sciences
Bone substitute materials are placed in bone defects and play an important role in bone regeneration and fracture healing. The main objective of the present research is fabrication through the technique of 3D printing and the characterization of innovative composite bone scaffolds composed of polylactic acid (PLA), poly (ε-caprolactone) (PCL) while hydroxyapatite (HAp), and/or barium titanate (BaTiO3—BT) used as fillers. Composite filaments were prepared using a single screw melt extruder, and finally, 3D composite scaffolds were fabricated using the fused deposition modeling (FDM) technique. Scanning electron microscopy (SEM) images showed a satisfactory distribution of the fillers into the filaments and the printed objects. Furthermore, differential scanning calorimetry (DSC) measurements revealed that PLA/PCL filaments exhibit lower glass transition and melting point temperatures than the pure PLA filaments. Finally, piezoelectric and dielectric measurements of the 3D objects sho...
Journal of Materials Research, 2018
This work aims at providing guidance through systematic experimental characterization, for the design of 3D printed scaffolds for potential orthopaedic applications, focusing on fused deposition modeling (FDM) with a composite of clinically available polycaprolactone (PCL) and β-tricalcium phosphate (β-TCP). First, we studied the effect of the chemical composition (0% to 60% β-TCP/ PCL) on the scaffold's properties. We showed that surface roughness and contact angle were respectively proportional and inversely proportional to the amount of β-TCP, and that degradation rate increased with the amount of ceramic. Biologically, the addition of β-TCP enhanced proliferation and osteogenic differentiation of C3H10. Secondly, we systematically investigated the effect of the composition and the porosity on the 3D printed scaffold mechanical properties. Both an increasing amount of β-TCP and a decreasing porosity augmented the apparent Young's modulus of the 3D printed scaffolds. Third, as a proof-of-concept, a novel multi-material biomimetic implant was designed and fabricated for potential disk replacement.
Polymers
The still-growing field of additive manufacturing (AM), which includes 3D printing, has enabled manufacturing of patient-specific medical devices with high geometrical accuracy in a relatively quick manner. However, the development of materials with specific properties is still ongoing, including those for enhanced bone-repair applications. Such applications seek materials with tailored mechanical properties close to bone tissue and, importantly, that can serve as temporary supports, allowing for new bone ingrowth while the material is resorbed. Thus, controlling the resorption rate of materials for bone applications can support bone healing by balancing new tissue formation and implant resorption. In this regard, this work aimed to study the combination of polylactic acid (PLA), polycaprolactone (PCL) and hydroxyapatite (HA) to develop customized biocompatible and bioresorbable polymer-based composite filaments, through extrusion, for fused filament fabrication (FFF) printing. PLA ...
Polymers
Manufacturing three-dimensional (3D) objects with polymers/bioceramic composite materials has been investigated in recent years. In this study, we manufactured and evaluated solvent-free polycaprolactone (PCL) and beta-tricalcium phosphate (β-TCP) composite fiber as a scaffold material for 3D printing. To investigate the optimal ratio of feedstock material for 3D printing, the physical and biological characteristics of four different ratios of β-TCP compounds mixed with PCL were investigated. PCL/β-TCP ratios of 0 wt.%, 10 wt.%, 20 wt.%, and 30 wt.% were fabricated, with PCL melted at 65 °C and blended with β-TCP with no solvent added during the fabrication process. Electron microscopy revealed an even distribution of β-TCP in the PCL fibers, while Fourier transform infrared spectroscopy demonstrated that the biomaterial compounds remained intact after the heating and manufacturing process. In addition, adding 20% β-TCP into the PCL/β-TCP mixture significantly increased hardness and...
Production and Characterisation of PCL/ES Scaffolds for Bone Tissue Engineering
Materials Today: Proceedings, 2015
The combination of bio-fillers with synthetic polymers has been an exciting route for developing tissue engineering scaffolds, in particular for bone tissue regeneration. In this study, poly(ε-caprolactone) (PCL) scaffolds were produced using an additive manufacturing technique and eggshell (ES) powder was used as a filler. The morphology of PCL and PCL/ES scaffolds were analysed and the effect of ES in the polymer matrix was characterized using techniques of Differential Scanning Calorimetry and Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Diffraction (XRD). Morphological observation revealed that the incorporation of ES in the polymer matrix modifies the flow behaviour of the material in spite of the same processing parameters, resulting in a decrease of scaffold pore size. Thermal analysis showed that the addition of the bio-filler improves the crystallization properties and thermal stability of the PCL. FT-IR spectra of ES powder showed characteristic bands of calcium carbonate and processed materials spectra indicated no changes on the functional groups compared to non-processed materials. Crystalline nature of ES was demonstrated through a characteristic broad peak in XRD pattern around 30 o , which was also observed in the composites XRD spectra. The results indicate the potential of ES powder to be used as a filler for bio-based polymer scaffold composites.