3D-Printed PLA-Bioglass Scaffolds with Controllable Calcium Release and MSC Adhesion for Bone Tissue Engineering

Abstract

Large bone defects are commonly treated by replacement with auto- and allografts, which have substantial drawbacks including limited supply, donor site morbidity, and possible tissue rejection. This study aimed to improve bone defect treatment using a custom-made filament for tissue engineering scaffolds. The filament consists of biodegradable polylactide acid (PLA) and a varying amount (up to 20%) of osteoconductive S53P4 bioglass. By employing an innovative, additive manufacturing technique, scaffolds with optimized physico-mechanical and biological properties were produced. The scaffolds feature adjustable macro- and microporosity (200–2000 µm) with adaptable mechanical properties (83–135 MPa). Additionally, controllable calcium release kinetics (0–0.25 nMol/µL after 24 h), tunable mesenchymal stem cell (MSC) adhesion potential (after 24 h by a factor of 14), and proliferation (after 168 h by a factor of 18) were attained. Microgrooves resulting from the 3D-printing process on the surface act as a nucleus for cell aggregation, thus being a potential cell niche for spheroid formation or possible cell guidance. The scaffold design with its adjustable biomechanics and the bioglass with its antimicrobial properties are of particular importance for the preclinical translation of the results. This study comprehensibly demonstrates the potential of a 3D-printed bioglass composite scaffold for the treatment of critical-sized bone defects.

In vitro Evaluation of a 20% Bioglass-Containing 3D printable PLA Composite for Bone Tissue Engineering

“…This allows the continuous release of bioactive ions during the degradation process. The dose-dependent accumulation of calcium ions from the test particles in initially calcium-free PBS could be demonstrated by us[ 37 ]. The calcium concentration was about 0.35 nmol/µL after 7 days of incubation of a BG20 sample.…”

“…To investigate a possible influence of calcium ions released from BG20 on MSC, we performed an analogous experiment with BG20. Calcium ions were selectively bound by EGTA, and the amount of EGTA added was based on the expected calcium ion release, which was previously determined by colorimetric detection[ 37 ]. IL-6 gene expression was chosen as the readout parameter because it is rapidly and significantly downregulated by BG20.…”

“…The expression of the IL-6 gene marker was selected for this purpose, since its expression was strongly attenuated by incubation with BG20. From preliminary experiments, it is known that within 72 h, an average of 0.35 nmol/µL calcium is released from a test sample BG20[ 37 ]. Here, 200 mL of normal medium was conditioned over 72 h with one BG20 or PLA specimen as control.…”

Design, fabrication, mechanical, and in vitro evaluation of 3D printed ZrO2 reinforced polylactide scaffolds through fused deposition modeling

“…30,31 Moreover, the fabrication of ZrO 2 scaffolds through modern 3D printing techniques is laborious, and the attainment of desired scaffold design becomes a challenging task. 32 Other than the research investigations reported on bioactive calcium phosphate and bioglass reinforced 3D printed PLA scaffolds, [33][34][35] the studies on the development of 3D printed ZrO 2 based scaffolds have been rather scarcely documented. In this context, the present study aims to develop ZrO 2 based PLA scaffold through the FDM technique for its suitability in BTE.…”

Sterilization of PLA after Fused Filament Fabrication 3D Printing: Evaluation on Inherent Sterility and the Impossibility of Autoclavation

“…Especially the use of multiple bioresorbable printing materials, such as polylactic acid (PLA) or polycaprolactone (PCL), adds further advantages. Trauma surgery and orthopedics, in particular, benefit from the possible applications ranging from use as bone substitute material [ 2 , 3 ], patient-specific implants [ 4 , 5 ], preoperative planning [ 6 ], use in teaching [ 7 ], or as protective equipment [ 8 ]. The requirements are as varied as the possible demands [ 1 ].…”