Powder 3D Printing of Bone Scaffolds with Uniform and Gradient Pore Sizes Using Cuttlebone-Derived Calcium Phosphate and Glass-Ceramic

Abstract

The pore geometry of bone scaffolds has a major impact on their cellular response; for this reason, 3D printing is an attractive technology for bone tissue engineering, as it allows for the full control and design of the porosity. Calcium phosphate materials synthesized from natural sources have recently attracted a certain interest because of their similarity to natural bone, and they were found to show better bioactivity than synthetic compounds. Nevertheless, these materials are very challenging to be processed by 3D printing due to technological issues related to their nanometric size. In this work, bone scaffolds with different pore geometries, with a uniform size or with a size gradient, were fabricated by binder jetting 3D printing using a biphasic calcium phosphate (BCP) nanopowder derived from cuttlebones. To do so, the nanopowder was mixed with a glass-ceramic powder with a larger particle size (45–100 µm) in 1:10 weight proportions. Pure AP40mod scaffolds were also printed. The sintered scaffolds were shown to be composed mainly by hydroxyapatite (HA) and wollastonite, with the amount of HA being larger when the nanopowder was added because BCP transforms into HA during sintering at 1150 °C. The addition of bio-derived powder increases the porosity from 60% to 70%, with this indicating that the nanoparticles slow down the glass-ceramic densification. Human mesenchymal stem cells were seeded on the scaffolds to test the bioactivity in vitro. The cells’ number and metabolic activity were analyzed after 3, 5 and 10 days of culturing. The cellular behavior was found to be very similar for samples with different pore geometries and compositions. However, while the cell number was constantly increasing, the metabolic activity on the scaffolds with gradient pores and cuttlebone-derived powder decreased over time, which might be a sign of cell differentiation. Generally, all scaffolds promoted fast cell adhesion and proliferation, which were found to penetrate and colonize the 3D porous structure.

Additive Manufacturing of Bioceramic Implants for Restoration Bone Engineering: Technologies, Advances, and Future Perspectives

“…Xu et al 46 used the SLS technique to prepare polymer/hydroxyapatite composite scaffolds with micro-and nanobioactive surfaces, which have a high mineralization capacity, excellent wettability, and better cytocompatibility. Cestari et al 47 printed biphasic calcium phosphate (BCP) through BJ as bone scaffolds with different pore geometries, uniform size or size gradients, and the scaffolds all exhibited good printability and underwent cellular differentiation. However, among these AM technologies, digital light processing (DLP, which belongs to VP), stereolithography apparatus (SLA, which belongs to VP), DIW (which belongs to ME), and FDM (which belongs to ME) are commonly used to prepare bioceramics and are the frequently reported AM technologies.…”

Property and biological effects of the cuttlebone derived calcium phosphate particles, a potential bioactive bone substitute material

“…MSCs could be influenced by physical and chemical properties of bone graft materials 29 and hDPSCs can be triggered toward osteogenic and odontoblastic differentiations by BCPs, 28,30 hDPSCs are applied in cell culture models to test biocompatibility and bioactivity of the bone substitute particles for promoting bone regeneration 30,31 and dentine formation for dental pulp capping material. 28 The current study aimed to explore an applicability of the 60:40 HA/bTCP, CB-BCP particles for bio derived bone substitute materials.…”

3D Printing in Regenerative Medicine: Technologies and Resources Utilized

“…Its semi-crystalline shape permits optimal oxygen and nutrient delivery to the cell, and its hydrophilicity and chemical stability allow for exposure to high pH and temperature conditions. PVA is widely employed in a variety of load-bearing implant applications, including bone-tissue-regeneration procedures and cranio-facial deformities [ 45 , 46 ].…”