Bionic Organs: Shear Forces Reduce Pancreatic Islet and Mammalian Cell Viability during the Process of 3D Bioprinting

Abstract

Background: 3D bioprinting is the future of constructing functional organs. Creating a bioactive scaffold with pancreatic islets presents many challenges. The aim of this paper is to assess how the 3D bioprinting process affects islet viability. Methods: The BioX 3D printer (Cellink), 600 μm inner diameter nozzles, and 3% (w/v) alginate cell carrier solution were used with rat, porcine, and human pancreatic islets. Islets were divided into a control group (culture medium) and 6 experimental groups (each subjected to specific pressure between 15 and 100 kPa). FDA/PI staining was performed to assess the viability of islets. Analogous studies were carried out on α-cells, β-cells, fibroblasts, and endothelial cells. Results: Viability of human pancreatic islets was as follows: 92% for alginate-based control and 94%, 90%, 74%, 48%, 61%, and 59% for 15, 25, 30, 50, 75, and 100 kPa, respectively. Statistically significant differences were observed between control and 50, 75, and 100 kPa, respectively. Similar observations were made for porcine and rat islets. Conclusions: Optimal pressure during 3D bioprinting with pancreatic islets by the extrusion method should be lower than 30 kPa while using 3% (w/v) alginate as a carrier.

Microfluidic device integrating a network of hyper-elastic valves for automated glucose stimulation and insulin secretion collection from a single pancreatic islet

“…To determine the sear stress imposed to the islet during the GSIS-assay protocol, the flow in the main serpentine channel was modeled using COMSOL Multiphysics. While it has already been shown that microfluidic continuous perifusion positively affects islets function and survival (Sankar et al, 2011) , too high shear stress can cause cell deformation and lead to permanent damage (Klak et al, 2021) . To model our experimental conditions, atmospheric pressure was assigned at the inlet wall and a flow rate of 100 μL/min or 2.5 μL/min was assigned at the outlet (Fig.…”

Making human pancreatic islet organoids: Progresses on the cell origins, biomaterials and three-dimensional technologies

“…In islet 3D bioprinting, it is essential to optimize the shear stress (pressure, nozzle diameter, printing speed), which can reduce cell viability by up to 40-85%. Klak and colleagues found that comparing with the large size islets, smaller size human islets (50-100 μm) have survival advantage under the same mechanical pressures, and the optimal pressure by the extrusion method should be lower than 30 kPa while using 3% (w/v) alginate as a carrier 150 . In a microfluidic platform, the shear stress is determined by flow rate and affects the morphology and function of islet organoids 56 .…”

Three-Dimensional Bioprinting of Decellularized Extracellular Matrix-Based Bioinks for Tissue Engineering

“…In addition, extrusion-based bioprinting can be adapted to create vascular structures with coaxial nozzles. Despite the advantages and successes, the drawbacks are relatively obvious, such as a low print resolution [ 122 ] and shear force affecting cell viability [ 123 ]. To solve the poor extrusion printability of dECM bioinks, the use of multiple material composite, especially nanoparticles, has become a widespread approach.…”