Directed cell growth in multi-zonal scaffolds for cartilage tissue engineering

Abstract

Articular cartilage serves as a low-friction cushion in synovial joints and is vital for mammalian skeletal movements. Due to its avascular nature and the low cell density, the tissue has a limited ability to regenerate, and damage due to injury, wear and tear, or disease usually requires surgical intervention. While articular cartilage had been predicted to be one of the first tissues to be successfully engineered, it proved to be challenging to reproduce the complex architecture and biomechanical properties of the native tissue. Here we report the fabrication of multi-layer polymer nanocomposite scaffolds that mimic the structural design, chemical cues, and mechanical characteristics of mature articular cartilage. These scaffolds guide the morphology, orientation, and phenotypic state of cultured chondrocytes in a spatially controlled manner, support the growth of tissue with features that are reminiscent of the natural analogue, and promote localized hydroxyapatite formation to permit integration with the subchondral bone.

Biomimetic multidirectional scaffolds for zonal osteochondral tissue engineering via a lyophilization bonding approach

“…This pore size is suitable to support the chondrogenesis of MSCs; similar lyophilized isotropic collagen‐hyaluronic acid scaffolds with a mean pore size of 94 µm were found to promote early stage chondrogenesis of MSCs in vitro . Furthermore, the combination of this isotropic morphology with negatively charged carboxyl groups of hyaluronic acid may promote a desired spherical morphology of seeded cells, akin to that of transition zone chondrocytes . The cytoskeletal arrangement in round MSCs upregulates chondrogenic gene expression by altering the interaction of cells with TGF‐B3, decreasing N‐cadherin and Rac1 activity …”

Composite Hydrogels with Tunable Anisotropic Morphologies and Mechanical Properties

“…Since many tissues, e.g., striated muscle, 6 cartilage, 7 or cornea 8 , to name just a few examples, have anisotropic hierarchical morphologies, there is a growing interest in developing approaches for the fabrication of anisotropic hydrogels that exhibit direction-dependent pore shape, microstructure, stiffness, and conductivity. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] In tissue engineering, aside from biomimicry, anisotropic pore shape and hydrogel structure, in general, are important for cell guidance 22 and differentiation, 23 as well as mass transport of biofactors and nutrients throughout the scaffold. 19,24,25 In bioseparation, control over the shape anisotropy of hydrogel pores may enhance the selectivity of the filtration of biological species and/or minimize the pressure drop across the matrix.…”

Cooperative Ordering and Kinetics of Cellulose Nanocrystal Alignment in a Magnetic Field

“…9 Furthermore, chiral nematic thin films are iridescent and selectively reflect light, which may be useful for optical possibilities and guidance for directional cell growth and orientation-induced differentiation; 17,18 however, applications such as these require near-perfect orientation. As such, having a straightforward and reproducible way to manipulate CNC alignment is crucial for further development of functional materials.…”