Quanle Cao

Bio: Quanle Cao is an academic researcher from Sichuan University. The author has contributed to research in topics: Materials science & Ceramic. The author has an hindex of 1, co-authored 3 publications receiving 13 citations.

Stereolithography-Based Additive Manufacturing of High-Performance Osteoinductive Calcium Phosphate Ceramics by a Digital Light-Processing System

Abstract: Digital light processing (DLP) is one of the additive manufacturing (AM) technologies suitable for preparation of high-performance ceramics. The present study provided an optimized formula to fabricate osteoinductive calcium phosphate (CaP) ceramics with high precision and controllable three-dimensional (3D) structure. Among the four surfactants, monoalcohol ethoxylate phosphate was the best one to modify the CaP powders for preparing the photocurable slurry with high solid loading and good spreading ability. By testing the photopolymerization property of the 60 wt % solid loading slurry, the appropriate processing parameters including the slice thickness (50 μm), exposure intensity (10.14 mW/cm2), and exposure time (8 s) were set to perform the 3D printing of the ceramic green body in the DLP system. After the debinding and sintering, the final CaP ceramics were acquired. The stereomicroscope and SEM observation confirmed the high precision of the ceramics. The average compressive strength of the ceramics with 64.5% porosity reached 9.03 MPa. On only soaking in simulated body fluid for 1 day, an even layer of apatite formed on the ceramic surface. The cell culture confirmed that the ceramics could allow the good attachment, growth, and proliferation of murine bone marrow mesenchymal stem cells. After implantation into the dorsal muscles of beagle dogs for 3 months, abundant blood vessels and obvious ectopic bone formation were observed clearly by the histological evaluation. Therefore, with good bioactivity and osteoinductivity as well as high precision and adjustable mechanical strength, the 3D printed CaP ceramics in the DLP system could have good potential in customized bone-repairing applications.

Fabrication and biological evaluation of 3D-printed calcium phosphate ceramic scaffolds with distinct macroporous geometries through digital light processing technology

Abstract: Abstract Digital light processing (DLP)-based 3D printing technique holds promise in fabricating scaffolds with high precision. Here raw calcium phosphate (CaP) powders were modified by 5.5% monoalcohol ethoxylate phosphate (MAEP) to ensure high solid loading and low viscosity. The rheological tests found that photocurable slurries composed of 50 wt% modified CaP powders and 2 wt% toners were suitable for DLP printing. Based on geometric models designed by computer-aided design (CAD) system, three printed CaP ceramics with distinct macroporous structures were prepared, including simple cube, octet-truss and inverse face-centered cube (fcc), which presented the similar phase composition and microstructure, but the different macropore geometries. Inverse fcc group showed the highest porosity and compressive strength. The in vitro and in vivo biological evaluations were performed to compare the bioactivity of three printed CaP ceramics, and the traditional foamed ceramic was used as control. It suggested that all CaP ceramics exhibited good biocompatibility, as evidence by an even bone-like apatite layer formation on the surface, and the good cell proliferation and spreading. A mouse intramuscular implantation model found that all of CaP ceramics could induce ectopic bone formation, and foam group had the strongest osteoinduction, followed by inverse fcc, while cube and octet-truss had the weakest one. It indicated that macropore geometry was of great importance to affect the osteoinductivity of scaffolds, and spherical, concave macropores facilitated osteogenesis. These findings provide a strategy to design and fabricate high-performance orthopedic grafts with proper pore geometry and desired biological performance via DLP-based 3D printing technique.

Effect of Hydrothermal Media on the in-situ Whisker Growth on Biphasic Calcium Phosphate Ceramics

Abstract: Background There is still a big challenge to achieve a balance between mechanical characteristics and biological properties in biphasic calcium phosphate (BCP) ceramics. Purpose The present study focused on the in-situ whisker growth on BCP ceramics via different hydrothermal treatments and investigated the influences of these whiskers on the mechanical property and biological performance of the ceramics. Methods Five kinds of BCP ceramics with in-situ whisker growth, ie, BCP-C, BCP-HNO3, BCP-Citric, BCP-NaOH, BCP-CaCl2 and BCP-Na3PO4 were fabricated by different hydrothermal treatments. The phase compositions, morphologies, crystal structures and mechanical strengths of the obtained BCP ceramics were firstly characterized. Then, the in vitro cell adhesion, proliferation and alkaline phosphatase (ALP) activity of bone marrow stromal cells (BMSCs) on the BCP ceramics were evaluated. Lastly, the effects of in-situ whisker growth on the bone-like apatite formation abilities of BCP ceramics were also investigated by immersing them in simulated body fluid (SBF). Results The results demonstrated that the hydrothermal conditions, especially the hydrothermal media, were crucial to determine the phase composition and morphology of the in-situ whisker. Especially among the five media used (HNO3, Citric, NaOH, CaCl2 and Na3PO4), the Na3PO4 treatment resulted in the shortest whisker with a unique hollow structure, and kept the original biphasic composition. All five kinds of whiskers increased the mechanical strength of BCP ceramics to some extent, and showed the good ability of bone-like apatite formation. The in vitro cell study demonstrated that the in-situ whisker growth had no adverse but even positive effect on the adhesion, proliferation and ALP activity of BMSCs. Conclusion Due to the growth of in-situ whiskers, the mechanical property and biological performance of the obtained BCP ceramics could increase simultaneously. Therefore, in-situ whiskers growth offers a promising strategy for the expanded application of BCP ceramics to meet the requirements of regenerative medicine.

A Novel Hollow‐Tube‐Biphasic‐Whisker‐Modified Calcium Phosphate Ceramics with Simultaneously Enhanced Mechanical Strength and Osteogenic Activity

Abstract: Due to the inherent brittleness and low mechanical strength, it is still a challenge for calcium phosphate (Ca‐P) ceramics to be used in load‐bearing bone defect repair. To achieve a good balance between mechanical strength and osteogenic activity, hollow‐tube‐whisker‐modified biphasic calcium phosphate (BCP) ceramics (BCP‐HW) are successfully fabricated by an in situ growth process in the present study. Compared to the initial BCP ceramics (BCP‐C) and those with solid whiskers, BCP‐HW exhibits larger specific surface area (3.9 times vs BCP‐C) and higher mechanical strength (3.4 times vs BCP‐C), endowing it with stronger stimulation on adhesion, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells. In an intramuscular implantation model of canine, BCP‐HW shows excellent osteoinductivity and promotes the maturation of new bone, and the resultant compressive strength of the implant increases to ≈12 MPa at 3 months postoperatively. In another critical‐sized segmental bone defect model of rabbit femur, BCP‐HW has the best repairing effect. After implantation for 6 months, much more new bone ingrowth and higher bending load are observed in BCP‐HW than BCP‐C. Collectively, these findings suggest that the in situ hollow‐tube whisker construction possesses immense potential in expanding the applications of Ca‐P ceramics to load‐bearing bone defect repair.

3D printing for polymer/particle-based processing: A review

Abstract: The 3D printing method, alternatively known as additive manufacturing (AM), is promising for rapid tooling and layered micromanufacturing. However, significant fundamental research and applied study in the 3D printing area are still necessary to develop new manufacturing mechanisms for combining multi-materials for multiscale and multi-functionality behaviors. Among those materials, particles with unique mechanical, thermal, electrical, optical, and other functional properties can find broad applications in structural composites, thermal packaging, electrical devices, optoelectronics, biomedical implants, energy storage, filtration, and purification. This review will first briefly cover the 3D printing basics before presenting the critical factors in polymer/particle-based printing. We will then introduce a spectrum of different printing mechanisms, i.e., vat polymerization-based, jetting-based, material extrusion-based, powder bed fusion-based, and a few other less utilized 3D printing methods, with a summary of the processing parameters, advantages, disadvantages, and future challenges of each printing technique. During this discussion of 3D printing, we will also present generally used polymers and particles, namely, liquid monomers, viscous inks, compliant gels, stiff filaments, and loosely packed pellets containing micro and nanoscale particles. The emphasis of this review is on the general printing mechanisms applicable in particle- and polymer-relevant processing. To end, this review identifies provides future perspectives regarding some new application examples. Identifying challenges in materials science and manufacturing processes will give direction to the fabrication of multifunctional systems for diverse applications, especially when using multi-materials (e.g., polymers and particles) at multiple scales (e.g., nanoscale morphologies and macroscale structures) for multifunctional systems.

Progress and challenges towards additive manufacturing of SiC ceramic

Abstract: Silicon carbide (SiC) ceramic and related materials are widely used in various military and engineering fields. The emergence of additive manufacturing (AM) technologies provides a new approach for the fabrication of SiC ceramic products. This article systematically reviews the additive manufacturing technologies of SiC ceramic developed in recent years, including Indirect Additive Manufacturing (Indirect AM) and Direct Additive Manufacturing (Direct AM) technologies. This review also summarizes the key scientific and technological challenges for the additive manufacturing of SiC ceramic, and also forecasts its possible future opportunities. This paper aims to provide a helpful guidance for the additive manufacturing of SiC ceramic and other structural ceramics.

Additive manufacturing of cellular ceramic structures: from structure to structure-function integration

Abstract: Cellular ceramic structures (CCSs) have promising application perspectives in various fields. Recently, additive manufacturing (AM), usually known as three-dimensional printing (3D printing), has been increasingly adopted to produce CCSs. Usually, the structural properties of additively manufactured cellular ceramic structures (AM-CCSs), i.e., lightweight characteristics, load-bearing capacity, toughness, unconventional properties, are traditionally investigated. Interestingly, AM technologies have a significant advantage in achieving the structure–function integration for CCSs. Functional properties, e.g., electromagnetic property, acoustic property, thermal property, of CCSs can be achieved during the structural design synchronously. In this review, firstly, the AM technologies for CCSs are comparatively introduced. Then, structural AM-CCSs are summarized. After that, structure–function integrated AM-CCSs are further introduced in detail. Finally, challenges and opportunities towards structure–function integrated AM-CCSs are forecasted. This review is believed to give some guidance for the research and development of CCSs.