3D bioprinting of tissues and organs for regenerative medicine

Improved accuracy and precision of bioprinting through progressive cavity pump-controlled extrusion

“…3D bioprinting with its potential to position materials and cells in a precise 3-dimensional arrangement has gained growing interest for use in tissue and organ models, drug testing and regenerative medicine, leading to a tremendous growth in the bioprinting industry. [1] Starting from the first inkjet bioprinter, a modified HP 660C printer, the technology has evolved continuously and users can nowadays choose from a variety of commercially available bioprinting technologies. [2][3][4] These processes can be categorized based on the 4 main governing strategies: (i) laser induced forward transfer (ii) droplet-based bioprinting, (iii) extrusion-based bioprinting and (iv) stereolithography-based bioprinting, each of which can be further sub-categorized based on the exact mechanisms with which material and cells are positioned.…”

“…[2][3][4] These processes can be categorized based on the 4 main governing strategies: (i) laser induced forward transfer (ii) droplet-based bioprinting, (iii) extrusion-based bioprinting and (iv) stereolithography-based bioprinting, each of which can be further sub-categorized based on the exact mechanisms with which material and cells are positioned. [1] Among these, extrusion-based bioprinting is the most commonly used process to fabricate tissues and organs, mainly attributed to its ease of use, scalability and wide range of printable materials. The process functions by positive displacement of the material via a plunger either driven by pneumatic pressure (pneumatic extrusion) or a piston which displaces the plunger (piston driven extrusion).…”

“…[8] Furthermore, additional factors such as the mixing of the bioink or the removal of air bubbles are critical, as uneven flow and nozzle clogging due to inhomogeneities in the bioink are a commonly observed phenomenon, and pneumatic extrusion systems are particularly susceptible. [1,9] Especially highly viscous biomaterial inks and bioinks containing viscosifiers as well as micro-and nano-composite bioinks are difficult to print. Without online adjustment of the pressure to compensate for variations in the volume flow due to these inhomogeneities, the structural integrity as well as the shape fidelity of the bioprinted construct cannot be guaranteed.…”

Emerging Interventions for Elderly Patients—The Promise of Regenerative Medicine

“…The revolution in manufacturing that has resulted from three‐dimensional (3D) printing technology has created great interest in the application of 3D printing for regenerative medicine . 3D printed organ constructs have been used in drug toxicology studies, with some suggesting their potential for the eventual replacement of experimental animals in some studies, and 3D printed anatomical models of organs are being used for the training of surgeons .…”

“…The revolution in manufacturing that has resulted from threedimensional (3D) printing technology has created great interest in the application of 3D printing for regenerative medicine. 85 3D printed organ constructs have been used in drug toxicology studies, with some suggesting their potential for the eventual replacement of experimental animals in some studies, 86 and 3D printed anatomical models of organs are being used for the training of surgeons. 87 Although the goal of 3D printing of replacement organs for transplantation has yet to be realized, significant progress has been made in animal models with the bioprinting of skin constructs for burns, as well as that of skeletal muscle constructs for the restoration of muscle function after volumetric muscle loss.…”