Design and Dynamic Culture of 3D-Scaffolds for Cartilage Tissue Engineering

Abstract

Engineered scaffolds for tissue-engineering should be designed to match the stiffness and strength of healthy tissues while maintaining an interconnected pore network and a reasonable porosity. In this work, we have used 3D-plotting technique to produce poly-L-Lactide macroporous scaffolds with two different pore sizes. The ability of these macroporous scaffolds to support chondrocyte attachment and viability were compared under static and dynamic loading in vitro. Moreover, the 3D-plotting technique was combined with porogen-leaching, leading to macro/microporous scaffolds, so as to examine the effect of microporosity on the level of cell attachment and viability under similar loading condition. Canine chondrocytes’ cells were seeded onto the scaffolds with different topologies, and the constructs were cultured for up to 2 weeks under static conditions or in a bioreactor under dynamic compressive strain of 10% strain, at a frequency of 1 Hz. The attachment and cell growth of chondrocytes were examined by scanning electron microscopy and by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. A significant difference in cell attachment was observed in macroporous scaffolds with different pore sizes after 1, 7, and 14 days. Cell viability in the scaffolds was enhanced with decreasing pore size and increasing microporosity level throughout the culture period. Chondrocyte viability in the scaffolds cultured under dynamic loading was significantly higher (p<0.05) than the scaffolds cultured statically. Dynamic cell culture of the scaffolds improved cell viability and decreased the time of in vitro culture when compared to statically cultured constructs. Optimizing the culture conditions and scaffold properties could generate optimal tissue/constructs combination for cartilage repair.

Physical and biological characteristics of nanohydroxyapatite and bioactive glasses used for bone tissue engineering

“…Additive manufacturing (AM) technologies have shown promise in developing scaffolds with rigorously controlled internal architectures and mechanical properties for tissue and organ regeneration [172][173][174]. However, viscosity constraint is a stumbling block for the majority of extrusion-based AM techniques [175,176].…”

Strategic Design and Fabrication of Engineered Scaffolds for Articular Cartilage Repair

“…The presence of both macro and micropores are important in 3D scaffolds, as macropores (>50 µm) promote cell migration [68] and micropores promote cell–cell interaction and mass transport, which improve tissue formation especially in vivo [69]. Titanium alloy constructs with a small average pore size (13 μm) form thicker cartilage tissue with significantly greater proteoglycan and cell density than those with larger pore sizes (43 and 68 μm) [67].…”

The Effect of Scaffold Pore Size in Cartilage Tissue Engineering

“…An appropriate physicochemical environment that accounts for a physiological intracellular stress state deriving from the cell-biomaterial interaction may favor the recovery of a phenotypic cell expression (1,2). The maintenance of such a physiological adhesive configuration, which is primarily related to the microarchitecture of the scaffold, (8,12,13,(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). However, some results have indicated that chondrocyte phenotype and biosynthetic activity improved in collagen matrices containing smaller pores (28,29).…”