Novel advances in strategies and applications of artificial articular cartilage

Abstract

Artificial articular cartilage (AC) is extensively applied in the repair and regeneration of cartilage which lacks self-regeneration capacity because of its avascular and low-cellularity nature. With advances in tissue engineering, bioengineering techniques for artificial AC construction have been increasing and maturing gradually. In this review, we elaborated on the advances of biological scaffold technologies in artificial AC including freeze-drying, electrospinning, 3D bioprinting and decellularized, and scaffold-free methods such as self-assembly and cell sheet. In the following, several successful applications of artificial AC built by scaffold and scaffold-free techniques are introduced to demonstrate the clinical application value of artificial AC.

Tough Bonding of PVA Hydrogel-on-Textured Titanium Alloy with Varying Texture Densities in Swollen State

“…The time required to reach swelling equilibrium in physiological saline exceeds that in deionized water. This discrepancy arises from the presence of low concentrations of Na + and Cl – , inducing a salt-out effect that disrupts some hydrogen bonds between polymer chains, thus diminishing the stability of the hydrogel network …”

“…The maximum tensile strength of PVA hydrogel swollen in physiological saline represents a 50% reduction compared to deionized water. This decline can be primarily attributed to the presence of Na + and Cl – , which facilitate the partial dissociation of hydrogen bonds between PVA hydrogel molecular chains . Typical tensile stress–strain curves of PVA hydrogel after swelling for different periods of time are shown in Figure S1 (see Supporting Information).…”

“…This discrepancy arises from the presence of low concentrations of Na + and Cl − , inducing a salt-out effect that disrupts some hydrogen bonds between polymer chains, thus diminishing the stability of the hydrogel network. 4 However, swelling has a detrimental effect on the mechanical properties of the PVA hydrogel, resulting in reduced tensile strength and elastic modulus after immersion in deionized water and physiological saline (Figure 3(c,d)). For example, the tensile strength decreases by half for 48 h of swelling in deionized water, while further increases in swelling time do not significantly impact tensile properties.…”

“…Compared to swelling in deionized water, the interfacial toughness of the PVA hydrogelon-titanium alloy with the same texture density decreases when immersed in physiological saline solution, mainly due to the adverse effects of salt ions. 4 Effect of Dimple Shape. In order to explore the impact of texture on the bond between the hydrogel and the titanium alloy further, a triangular dimple texture with a texture density of 30% was investigated and compared to that of the circular dimple texture.…”

“…Articular cartilage lesions are a common symptom of osteoarthritis (OA), a prevalent disease that causes disability, even among young patients. , Unfortunately, the intrinsic inability of articular cartilage to self-heal due to its avascular and aneural nature has led to the extensive use of artificial cartilage materials to replicate its biofunction. − To date, no candidate materials have been able to fully replicate the natural cartilage’s function. Hydrogels are considered promising substitutes for damaged cartilage due to their similar porous biphasic structure with high water content. , However, their lack of adequate load-bearing capacities limits their broader application .…”