Effect of porosity on mechanical and biological properties of bioprinted scaffolds

Abstract

Treatment of tissue defects commonly represents a major problem in clinics due to difficulties involving a shortage of donors, inappropriate sizes, abnormal shapes, and immunological rejection. While many scaffold parameters such as pore shape, porosity percentage, and pore connectivity could be adjusted to achieve desired mechanical and biological properties. These parameters are crucial scaffold parameters that can be accurately produced by 3D bioprinting technology based on the damaged tissue. In the present research, the effect of porosity percentage (40%, 50%, and 60%) and different pore shapes (square, star, and gyroid) on the mechanical (e.g., stiffness, compressive and tensile behavior) and biological (e.g., biodegradation, and cell viability) properties of porous polycaprolactone (PCL) scaffolds coated with gelatin have been investigated. Moreover, human foreskin fibroblast cells were cultured on the scaffolds in the in-vitro procedures. MTT assay (4, 7, and 14 days) was utilized to determine the cytotoxicity of the porous scaffolds. It is revealed that the porous scaffolds produced by the bioprinter did not produce a cytotoxic effect. Among all the porous scaffolds, scaffolds with a pore size of about 500 μm and porosity of 50% showed the best cell proliferation compared to the controls after 14 days. The results demonstrated that the pore shape, porosity percentage, and pore connectivity have an important role in improving the mechanical and biological properties of porous scaffolds. These 3D bioprinted biodegradable scaffolds exhibit potential for future application as polymeric scaffolds in hard tissue engineering applications.

Fast‐Gelling Polyethylene Glycol/Polyethyleneimine Hydrogels Degradable by Visible‐Light

“…Structures with high porosity and interconnected pore structures can mimic naturally occurring structures, lead to improved gas and nutrient exchange, therefore improving the cell viability of the systems. [ 42,43 ] Consequently, as the porosity of the materials increased with the decrease of the weight percentage of the hydrogels, the hydrogels with 30 wt.% showed better results in the cell viability results, and the same is valid for the hydrogels after irradiation. [ 44,45 ]…”

Progress of Microfluidic Hydrogel‐Based Scaffolds and Organ‐on‐Chips for the Cartilage Tissue Engineering

“…[ 268 ] Scaffold pore size is a determining parameter affecting the efficiency of cartilage regeneration. [ 269–271 ] According to the previous studies, scaffolds with 150–500 µm pore size can considerably enhance chondrocytes’ adhesion, proliferation, and ECM production, [ 125 ] with 150–250 µm being the optimum value. [ 272 ] For instance, the pure bacterial cellulose's (pure BC) pore size is 0.05–10 µm, relatively smaller than the mammalian cells’ dimensions.…”

Photo-cross-linkable hyaluronic acid bioinks for bone and cartilage tissue engineering applications

“…Bioprinting allows the layer-by-layer deposition of cell-laden hydrogels to produce constructs/scaffolds with predefined architecture, allowing the controlled construction of personalized and large-scale living tissue-like structures in a rapid and high-throughput manner [14,15]. Bioprinting methods such as lithography and extrusion-based bioprinting have been adapted for the biofabrication of functional, reproducible, and precision cell-laden scaffolds in order to construct bone and cartilage-like tissues [16,17].…”