Bio-inspired zonal-structured matrices for bone-cartilage interface engineering

Abstract

Design and development of scaffold structures for osteochondral (OC) interface regeneration is a significant engineering challenge. Recent efforts are aimed at recapitulating the unique compositional and hierarchical structure of an OC interface. Conventional scaffold fabrication techniques often have limited design control and reproducibility, and the development of OC scaffolds with zonal hierarchy and structural integrity between zones is especially challenging. In this study, a series of multi-zonal and gradient structures were designed and fabricated using three-dimensional (3D) bioprinting. We developed OC scaffolds with bi-phasic and tri-phasic configurations to support the zonal structure of OC tissue, and gradient scaffold configurations to enable smooth transitions between the zones to more closely mimic a bone-cartilage interface. A biodegradable polymer, polylactic acid (PLA), was used for the fabrication of zonal/gradient scaffolds to provide mechanical strength and support OC function. The formation of the multi-zonal and gradient scaffolds was confirmed through SEM imaging and micro-CT scanning. Precisely controlled hierarchy with tunable porosity along the scaffold length established the formation of the bio-inspired scaffolds with different zones/gradient structure. In addition, we also developed a novel bioprinting method to selectively introduce cells into desired scaffold zones of the zonal/gradient scaffolds via concurrent printing of a cell-laden hydrogel within the porous template. Live/dead staining of the cell-laden hydrogel introduced in the cartilage zone showed uniform cell distribution with high cell viability. Overall, our study developed bio-inspired scaffold structures with structural hierarchy and mechanical integrity for bone-cartilage interface engineering.

Articular Cartilage Regeneration through Bioassembling Spherical Micro-Cartilage Building Blocks

“…This approach can preserve the good mechanical strength of a polymer scaffold and maintain a high cellular density. However, because polymer needs to be printed at high temperatures (from 100 °C to 230 °C), one drawback of this method is thermal stresses from polymer structs resulting cell death [ 94 ]. In another example, polymer material was initially used to 3D print a slab consisting of fibrous microchambers ( Figure 3 (D1–D4)).…”

3D printing of bone and cartilage with polymer materials

“…Polylactic acid (PLA) was used for the fabrication of zonal/gradient scaffolds to provide mechanical strength. It revealed structural hierarchy and mechanical integrity for bone-cartilage interface engineering ( Golebiowska and Nukavarapu, 2022 ).…”

“…In bone and cartilage tissue engineering, the main advantage of 3D bio printing is that it can print scaffolds with controlled distribution of cells, promoting cartilage tissue regeneration. In addition to the limitations of its technology in the application process, the choice of printing materials also plays a crucial role ( De Angelis et al, 2021 ; Jang et al, 2020 ; Fan et al, 2020 ; Cao et al, 2021 ; Golebiowska and Nukavarapu, 2022 ). Materials currently used in 3D printing natural bones and bone scaffolds include metal materials, inorganic non-metallic materials, and polymer materials.…”

A triphasic biomimetic BMSC-loaded scaffold for osteochondral integrated regeneration in rabbits and pigs

“…Inhomogeneous scaffolds with different mechanical strengths, structures and cell/growth factorloading are needed to meet the demand. [8][9][10][11] The structure and mechanical properties can be altered through material selection. For instance, the hybrid gel whose stiffness gradient increases longitudinally with the low-molecular-weight gel mimicking cartilage and poly(ethylene glycol) diacrylate gel mimicking the bone.…”