Pore architecture effects on chondrogenic potential of patient-specific 3-dimensionally printed porous tissue bioscaffolds for auricular tissue engineering

Abstract

Image-based computer-aided design and 3D printing offers an exciting new avenue for the tissue-engineered auricle. In early pilot work, creation of spherical micropores within the scaffold architecture appears to impart greater chondrogenicity of the bioscaffold. This advantage could be related to differences in permeability allowing greater cell migration and nutrient flow, differences in surface area allowing different cell aggregation, or a combination of both factors. The ability to design an anatomically correct scaffold that maintains its structural integrity while also promoting auricular cartilage growth represents an important step towards clinical applicability of this new technology.

A Numerical Study of Fluid Flow in the Porous Structure of Biological Scaffolds

“…In previous studies, we have shown that HAP has a positive effect on migration, proliferation, and differentiation of cells and their bonding to scaffold, which was prepared in the form of a matrix based on polymer nanosized fibers with the addition of HAP particles [29][30][31][32][33][34]. Based on the obtained in our studies results, as well as on the studies carried out in experimental works devoted to the study of biological scaffolds [35][36][37], fabricated by 3D printing technology, we modeled composite scaffolds with different types of structures, and the significant difference between the indicated above studies and our model was the content of HAP, which in our scaffolds did not exceed 10%. According to [38] the presence of HAP in the scaffold structure over 10% adversely affects its mechanical properties.…”

Co‐culture of adipose‐derived stem cells and chondrocytes on three‐dimensionally printed bioscaffolds for craniofacial cartilage engineering

“…Our group has previously performed studies, demonstrating that a spherical pore microarchitecture results in improved cell survival and cartilage deposition for CTE. 38 This process affords the ability to rapidly chondrogenically while also allowing meticulous control of the pore microarchitecture. However, our prior investigations have been limited by many of the previously described constraints, including the limited number of chondrocytes available for harvest, the need to passage chondrocytes in cell culture, and the need for prolonged exogenous GF exposure.…”

Reviewing recently developed technologies to direct cell activity through the control of pore size: From the macro‐ to the nanoscale

“…In the last years, the rising of AM techniques has opened the ways to the development of macropore size‐controlled scaffolds using a wide variety of materials and permitting a greater control of pore geometry (Tran & Wen, ; Zopf et al, ). However, macropore can strongly affect the mechanical performance of the scaffold and the optimal pore size for cell response should be defined avoiding any structural damaging.…”

“…For instance, several studies investigated human bone topological features to resemble its unique hierarchical structure at different scales (Yuan et al, ; Zhang, Fang, Xing, Liu, & Zhou, ). Pore size affects the response of the hosting cells in a different way (Loh & Choong, ): nanopores (<300 nm in size; Cox & Dunand, ; Merhie, Salerno, Toccafondi, & Dante, ) promotes cell adhesion increasing the surface area, micropores (0.3–100 μm in size; Cox & Dunand, ; Sherborne, Owen, Reilly, & Claeyssens, ) enhance the permeability of the scaffold and facilitate cell migration while macropores (>100 μm in size; Bruzauskait, Bironaite, Bagdonas, Bernotiene, ; Salerno, Guarnieri, Iannone, Zeppetelli, & Netti, ; Zopf, Flanagan, Mitsak, Brennan, & Hollister, ) provide space for vascularization and tissue ingrowth, favor gas diffusion, nutrients supply, and waste removal (Figure ). The effect of pore size on cell activity has been extensively investigated (Table ), as it represents an efficient mean to modify the tissue response in vivo by acting on geometrical features instead of compositional cues (Bruzauskait et al, ; Jeon, Simon, & Kim, ).…”

“…So far, stereolithography, selective laser sintering, selective laser melting, electron beam melting, 3D‐bioprinting, direct laser writing, fused deposition modeling are the more common AM technologies applied in tissue engineering (Stachewicz, Szewczyk, Kruk, Barber, & Czyrska‐Filemonowicz, ; Zaharin et al, ). Furthermore, the use of AM technologies allows to control not only the pore size, but even the pore geometry which has been recently reported to be an effect on cell response (Wang et al, ; Zopf et al, ).…”