Biocompatibility and biodegradation studies of PCL/β-TCP bone tissue scaffold fabricated by structural porogen method

Abstract

Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite porogens fabricated by 3DP. The resolution of printed plaster porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP porogen method provide essential capability for bone tissue engineering.

Effects of hydroxyapatite filler on long-term hydrolytic degradation of PLLA/PCL porous scaffolds

“…Ang et al [64] found increased degradation of PCL-HAp composites with increasing mass loss at higher HAp contents in an accelerated degradation using NaOH 5M, although the mechanism of this degradation assay may hardly be relevant to explain our results. In most studies very short times are used (from 7 days to 6 weeks) and the weight losses observed are mainly due to inorganic phase dissolution (when using TCP, see for example Lu et al [65] or HAp in thin PCL layer Kim el al. [66]) as physical degradation of PCL is known to occur on a much larger timescale.…”

Polycaprolactone blends for fracture fixation in low load‐bearing applications

“…Ternary blends tested; PCL/PGA/TCP blends (80/10/10 and 70/10/20) retained the adhesive strength of the parent PCL adhesive while having an improvement in hydrophilicity. Porous PCL scaffolds containing 20% TCP have been described as degrading faster than PCL alone, while supporting osteoblast growth …”

Rapid prototyping technology and its application in bone tissue engineering

“…Furthermore, because the processes are performed at room temperature, heat-sensitive biologically active factors can be added during printing (Chia and Wu, 2015). However, the final products usually have weak biomechanical strength, which require high-temperature sintering to obtain structures suitable for bone tissue engineering (Seitz et al, 2005;Lu et al, 2012;Tarafder et al, 2013;Tarafder and Bose, 2014;Qian et al, 2015). Exploration of better binders is currently underway (Inzana et al, 2014).…”