Collagen in tissue-engineered cartilage: Types, structure, and crosslinks

Abstract

The function of articular cartilage as a weight-bearing tissue depends on the specific arrangement of collagen types II and IX into a three-dimensional organized collagen network that can balance the swelling pressure of the proteoglycan/water gel. To determine whether cartilage engineered in vitro contains a functional collagen network, chondrocyte-polymer constructs were cultured for up to 6 weeks and analyzed with respect to the composition and ultrastructure of collagen by using biochemical and immunochemical methods and scanning electron microscopy. Total collagen content and the concentration of pyridinium crosslinks were significantly (57% and 70%, respectively) lower in tissue-engineered cartilage that in bovine calf articular cartilage. However, the fractions of collagen types II, IX, and X and the collagen network organization, density, and fibril diameter in engineered cartilage were not significantly different from those in natural articular cartilage. The implications of these findings for the field of tissue engineering are that differentiated chondrocytes are capable of forming a complex structure of collagen matrix in vitro, producing a tissue similar to natural articular cartilage on an ultrastructural scale.

The use of specific chondrocyte populations to modulate the properties of tissue‐engineered cartilage

“…In all of the chondrocyte cultures, pyridinoline cross-link density was lower than that of native articular cartilage [4,16] but did, however, appear to be correlated with the collagen content of the in vitro-formed tissue. This could explain why previous studies have also observed a reduced collagen content as well as lower collagen cross-link density in tissue-engineered cartilage relative to native cartilage [40,42].…”

Engineering on the Straight and Narrow: The Mechanics of Nanofibrous Assemblies for Fiber-Reinforced Tissue Regeneration

“…Nanofibers can be tuned to range from as small as 50 nm up to several microns in diameter, and as such are many times smaller than most mammalian cells; in fact, they are similar in scale to collagen fibers normally present in the ECM. 38 This nano-and micronscale topography has been shown to modulate cell signaling pathways 39 and to elicit superior metabolic and matrix forming activities by seeded cells. 40 Nanofibrous meshes are porous structures with a continuous distribution of pore sizes in the range of 2-465 mm and void volumes of 80-90%.…”

Exploiting the Natural Diversity in Adenovirus Tropism for Therapy and Prevention of Disease

“…There is a substantial medical need for tissues such as skin, cartilage, and bone due to the increasingly aging population and the resulting wear of body parts (6,21,22,25,27,31). For bone replacement surgery, such as revision hip arthroplasty, spine fusions, and jaw augmentation, the currently used bone grafts are mainly from allogeneic or autologous origin.…”