Design and Fabrication of a Hierarchically Structured Scaffold for Tendon‐to‐Bone Repair

Abstract

A hierarchically structured scaffold is designed and fabricated for facilitating tendon-to-bone repair. The scaffold is composed of three regions with distinct functions: (i) an array of channels to guide the in-growth of cells and aligned deposition of collagen fibers, as well as integration of the scaffold with the tendon side, (ii) a region with a gradient in mineral composition to facilitate stress transfer between tendon and bone, and (iii) a mineralized inverse opal region to promote the integration of the scaffold with the underlying bone. Cell culture experiments confirm that adipose-derived stromal cells are able to infiltrate and proliferate through the entire thickness of the scaffold without compromised cell viability. The seeded stem cells exhibit directed differentiation into tenocytes and osteoblasts along the mineral gradient as a response to the gradient in Young's modulus. This novel scaffold holds great promise to promote the formation of a functional tendon-to-bone attachment by offering a structurally and compositionally appropriate microenvironment for healing.

Bioinspired Wear‐Resistant and Ultradurable Functional Gradient Coatings

“…Temporally, the duration to reach equilibrium gradient is also controlled by the processing conditions mentioned above and can be accelerated by additionally applying mechanical stimuli to the sample during the magnetic exposure . These excellent controllability, together with the breakthrough in the magnitude and smoothness of the mechanical gradient by using hybrid nanoparticles presented here, clearly outperforms the alternative manufacturing techniques for gradient materials reported in the literature …”

“…The LC also presented considerable stress concentrations within the interfacial region but the stress level was much lower than that of the HC, in accordance with the better interfacial durability of the former. The FGC, due to the gradiently distributed mechanical and thermal properties crossing the coating thickness, well eliminated the stress singularities at the interfacial region and thus maintained the interfacial integrity even after the extensive cyclic loadings . Only a small fraction of high stresses was concentrated at the top surface of the FGC where the material stiffness and strength were also very high due to the closely packed hybrid nanoreinforcements.…”

“…Traditional methods for fabrication of FGCs include layer‐by‐layer deposition, slip casting, centrifugal sedimentation, chemical/physical vapor deposition, and so on . These methods, however, apply only to coatings with thickness of at least sub‐millimeters and they usually produce stepped (i.e., not smooth) gradient structures crossing the coating section . The presence of stepped transitions within coatings would impair the long‐term durability and damage‐tolerance when subjected to complicated and cyclic loadings .…”

Comparative Evaluation of the Book‐Type Acellular Bone Scaffold and Fibrocartilage Scaffold for Bone‐Tendon Healing

“…Among the above three factors, the scaffolds play the most critical role, which can give structural support, mimic the in vivo microenvironment and biologically influence the local cells, so as to regenerate the injured tissue with high‐efficiency . Currently, to precisely control the stiffness, alignment and surface topology of the scaffold, lots of artificial polymer materials have been designed to fabricate the scaffold for B‐T healing, such as poly lactic‐co‐glycolic acid, poly‐ N ‐acetyl glucosamine and electrospun scaffolds . However, these scaffolds composed of polymer materials remain uncertain in biosafety and insufficient in bioactivity, thus partly limiting their application .…”

The effect of different surface treatment methods on the physical, chemical and biological performances of a PGA scaffold

“…7,8 Due to its superior biodegradability [9][10][11] and biocompatibility [12][13][14] and other excellent properties, PGA can be a potential and promising candidate for biological cell scaffolds. [15][16][17][18] Scaffolds with a specic shape and a linked porous structure can be benecial for the cell adherence and growth, [19][20][21] and they have been widely applied in bone repair and bone tissue engineering. [22][23][24] In recent years, some researchers have made great efforts to improve the adhesion properties of the PGA scaffold.…”