A new 3D-printed polylactic acid-bioglass composite for bone tissue engineering induces angiogenesis in vitro and in ovo.

Large bone defects such as those that occur after trauma or resections due to cancer still are a challenge for surgeons. Main challenge in this area is to find a suitable alternative to the gold-standard therapy, which is highly risky, and a promising option is to use biomaterials manufactured by 3D printing. In former studies, we demonstrated that the combination of polylactic acid (PLA) and bioglass (BG) resulted in a stable 3D-printable material, and porous and finely structured scaffolds were printed. These scaffolds exhibited osteogenic and anti-inflammatory properties. This 3D-printed material fulfills most of the requirements described in the diamond concept of bone healing. However, the question remains as to whether it also meets the requirements concerning angiogenesis. Therefore, the aim of this study was to analyze the effects of the 3D-printed PLA-BG composite material on angiogenesis. In vitro analyses with human umbilical vein endothelial cells (HUVECs) showed a positive effect of increasing BG content on viability and gene expression of endothelial markers. This positive effect was confirmed by an enhanced vascular formation analyzed by Matrigel assay and chicken chorioallantoic membrane (CAM) assay. In this work, we demonstrated the angiogenic efficiency of a 3D-printed PLA-BG composite material. Recalling the osteogenic potential of this material demonstrated in former work, we manufactured a mechanically stable, 3D-printable, osteogenic and angiogenic material, which could be used for bone tissue engineering.

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

Three-dimensional (3D) printing is considered a key technology in the production of customized scaffolds for bone tissue engineering. In a previous work, we developed a 3D printable, osteoconductive, hierarchical organized scaffold system. The scaffold material should be osteoinductive. Polylactic acid (PLA) (polymer)/Bioglass (BG) (mineral/ion source) composite materials are promising. Previous studies of PLA/BG composites never exceed BG fractions of 10%, as increase of bioactive BG component negatively affects the printability of the composite material. Here, we test a novel, 3D printable PLA/BG composite with BG fractions up to 20% for its biological activity in vitro. PLA/BG filaments suitable for microstructure 3D printing were spun and the effect of different BG contents (5%, 10%, and 20%) in this material on mesenchymal stem cell (MSC) activity was tested in vitro. Our results showed that all tested composites are biocompatible. MSC cell adherence and metabolic activity increase with increasing BG content. The presence of BG component in scaffold has only slight effect on osteogenic gene expression, but it has significant suppressive effect on the expression of inflammatory genes in MSC. In addition, the material did not provoke any significant inflammatory response in whole-blood stimulation assay. The results show that by increasing the BG content, the bioactivity can be further enhanced.

Recent trends in bioartificial muscle engineering and their applications in cultured meat, biorobotic systems and biohybrid implants.

Recent advances in tissue engineering and biofabrication technology have yielded a plethora of biological tissues. Among these, engineering of bioartificial muscle stands out for its exceptional versatility and its wide range of applications. From the food industry to the technology sector and medicine, the development of this tissue has the potential to affect many different industries at once. However, to date, the biofabrication of cultured meat, biorobotic systems, and bioartificial muscle implants are still considered in isolation by individual peer groups. To establish common ground and share advances, this review outlines application-specific requirements for muscle tissue generation and provides a comprehensive overview of commonly used biofabrication strategies and current application trends. By solving the individual challenges and merging various expertise, synergetic leaps of innovation that inspire each other can be expected in all three industries in the future.

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

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.

Freeform direct laser writing of versatile topological 3D scaffolds enabled by intrinsic support hydrogel.

In this study, a novel approach to create arbitrarily shaped 3D hydrogel objects is presented, wherein freeform two-photon polymerization (2PP) is enabled by the combination of a photosensitive hydrogel and an intrinsic support matrix. This way, topologies without physical contact such as a highly porous 3D network of concatenated rings were realized, which are impossible to manufacture with most current 3D printing technologies. Micro-Raman and nanoindentation measurements show the possibility to control water uptake and hence tailor the Young's modulus of the structures via the light dosage, proving the versatility of the concept regarding many scaffold characteristics that makes it well suited for cell specific cell culture as demonstrated by cultivation of human induced pluripotent stem cell derived cardiomyocytes.