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Developing green and nontoxic biomaterials, derived from renewable sources and processable through 3D bioprinting technologies, is an emerging challenge of sustainable tissue engineering. Here, pectin from citrus peels was cross-linked for the first time with (3-glycidyloxypropyl)trimethoxysilane (GPTMS) through a one-pot procedure. Freeze-dried porous pectin sponges, with tunable properties in terms of porosity, water uptake, and compressive modulus, were obtained by controlling GPTMS content. Cell experiments showed that GPTMS did not affect the cytocompatibility of pectin. The addition of GPTMS improved the printability of pectin due to an increase of viscosity and yield stress. Three-dimensional woodpile and complex anatomical-shaped scaffolds with interconnected micro- and macropores were, therefore, bioprinted without the use of any additional support material. These results show the great potential of using pectin cross-linked with GPTMS as biomaterial ink to fabricate patient-specific scaffolds, which could be used to promote tissue regeneration in vivo.

The majority of strategies used in tissue engineering (TE) employ a scaffold, which is used to guide .the proliferation, the migration and the adhesione of cell in 3D to pruduce an engineered tissue. A new trend in scaffolds’s fabrication is represented by the hybrid Rapid Prototyping technologies. This is a new multimaterial and multiscale fabrication approach which combine the common RP technologies with other micro/nanofabrication techiques to fabricate scaffold that mimick the hetereogenty and hierarchical structure typical of the native extracellular matrix. In this new contest our work present: 1) an innovative device for the fabrication of multi material scaffolds based on an open source FDM 3D printer suitably modified to integrate a multi nozzle deposition tool 2) a design proposal for a multi material and multi scale machine to allow a full control over the modulation of the building materials and of the topography in a scaffold 3) and lastly a CAD workflow to guide the fabrication of RP patient specific scaffolds. Multifunctional hydrogel-based scaffold are fabricated as a demonstration of the validity of the proposed devices. Starting from a clinical case we print a patient-specific scaffold with the aim to recover bone defects at mandibular level as a validation of the proposed CAD process.

The majority of strategies used in tissue engineering (TE) employ a scaffold, which is used to guide .the proliferation, the migration and the adhesione of cell in 3D to pruduce an engineered tissue. A new trend in scaffolds’s fabrication is represented by the hybrid Rapid Prototyping technologies. This is a new multimaterial and multiscale fabrication approach which combine the common RP technologies with other micro/nanofabrication techiques to fabricate scaffold that mimick the hetereogenty and hierarchical structure typical of the native extracellular matrix. In this new contest our work present: 1) an innovative device for the fabrication of multi material scaffolds based on an open source FDM 3D printer suitably modified to integrate a multi nozzle deposition tool 2) a design proposal for a multi material and multi scale machine to allow a full control over the modulation of the building materials and of the topography in a scaffold 3) and lastly a CAD workflow to guide the fabrication of RP patient specific scaffolds. Multifunctional hydrogel-based scaffold are fabricated as a demonstration of the validity of the proposed devices. Starting from a clinical case we print a patient-specific scaffold with the aim to recover bone defects at mandibular level as a validation of the proposed CAD process.

The aim of this work is to design a robotic bioprinting platform able to fabricate a three-dimensional structure onto irregular surfaces. With respect to the limitations of current in vitrobioprinting approach, widely used in scaffold-based tissue engineering – handling difficulty, risk of contamination, shape not matching with the defect site – this robotic bioprinter can offer an innovative solution allowing in situbioprinting, a direct dispensing of biological materials onto and into the damaged site. The robotic platform was developed starting from the 5 degrees-of-freedom open source MOVEO robot from BCN3D. The hardware and the software of the original project were re-engineered to control the robot using LinuxCNC, a path planning algorithm was developed in Matlab®, and the end-effector was equipped with a pneumatic extruder. The algorithm automatically projects any generic printing pattern on the surface on which the scaffold will be 3D bioprinted. For each point, the algorithm calculates the joint angles to keep the end effector always perpendicular to the surface. A g-code file is then exported to Linux CNC adding parameters to control the air pressure and the printing speed. The robotic platform was tested to evaluate its performances. Resolution (∼200 μm) and repeatability were estimated and preliminary in situbioprinting tests were performed onto different irregular surfaces, including a physiologically relevant bone model.