Articular Cartilage Tissue Engineering

Strategies for Improving the Repair of Focal Cartilage Defects

“…In order to overcome the challenges associated with scaffold use, scaffold-free techniques promoting the formation of biomechanically functional neocartilage without using scaffolds have been proposed [5,[93][94]. Initially scaffold-free techniques were used to form small spherical aggregates of cells, for instance, by centrifugation, to study chondrogenesis.…”

“…Despite diverse approaches, nowadays there is no treatment able to restore hyalinelike cartilage with native tissue characteristics (Figure 2), which consists of an extracellular matrix (ECM) composed of water (70 to 80%), collagen (50 to 75% of dry weight) and glycosaminoglycans (GAGs) (15 to 30% of dry weight) [5]. This ECM composition confers cartilage functional viscoelastic properties able to sustain the specific compressive, tensile and frictional properties of the joint biomechanics [6].…”

Hydrogels and bioreactors for cartilage research and functional tissue engineering

“…Typically, the tissue is divided into four zones (superficial/tangential, middle/transitional, deep/radial and calcified zone) which can be identified by their unique biochemical composition and structure of the ECM, as well as the characteristic arrangement and morphology of the cells within the tissue [37,38] ( Figure 1.2). Similarly, due to the avascularity of the tissue, oxygen content decreases with increasing distance from the articulating surface.…”

“…The surface of articular cartilage is covered by an accellular, non-fibrous layer with a thickness from hundreds of nanometers to a few micrometers, termed lamina splendens [37,39]. Although the precise role of the lamina splendens is not known, it is hypothesized that this very thin layer provides low friction properties and protects the cartilage surface from wear and tear [40].…”

“…Although the precise role of the lamina splendens is not known, it is hypothesized that this very thin layer provides low friction properties and protects the cartilage surface from wear and tear [40]. Other hypotheses suggest the formation of the lamina splendens due to advancing accumulation of molecules and proteins from the synovial fluid, or that it is simply a visual artefact of cartilage microscopy [37]. However, different imaging techniques like confocal microscopy, scanning electron microscopy or atomic force microscopy have confirmed the presence of the lamina splendens in recent studies [41,42], suggesting that this may not be the case.…”