Proteoglycan degradation mimics static compression by altering the natural gradients in fibrillar organisation in cartilage

Abstract

Graphical abstract

An in silico Framework of Cartilage Degeneration That Integrates Fibril Reorientation and Degradation Along With Altered Hydration and Fixed Charge Density Loss

“…Experimental observations suggest the presence of interaction between PG and collagen degradations in cartilage ( Inamdar et al, 2019 ). The CARED model explicitly integrates the degenerative changes in the contents of collagen and PG constituents and therefore allows the elucidation of the interaction between the degenerative changes in the contents of individual constituents.…”

Biomaterials for protein delivery for complex tissue healing responses

“…Many native tissues contain gradients, such as cartilage and the osteochondral gradient between cartilage and bone. 134,135 As a result, biomaterial strategies have been developed to create gradients similar to tissues, including layer-bylayer [136][137][138][139] and 3D printing 140 strategies. Although there are three distinct layers in cartilage (superficial, middle, and deep zones), the challenge is to build many layers on top of one another to seamlessly transition from one zone to the next.…”

Spatiotemporal Measurement of Osmotic Pressures by FRET Imaging

“…[7] Another example is cartilage,w hich is stabilized by the swelling pressure of proteoglycans counter-balanced by the tension of (type II) collagen. [3,8] Fore xample,i ni ntact joints,t here is agentle grading of fixed charge density of cartilage and hence of osmotic pressure from the articular surface to the deep zone. [3,9] In addition, static and dynamic osmotic pressure gradients also occur in many other contexts from soil sciences, [10] to colloidal sciences, [11] water treatment, [12] energy generation, [13] material engineering, [14] and membrane filtration.…”

“…[3,8] Fore xample,i ni ntact joints,t here is agentle grading of fixed charge density of cartilage and hence of osmotic pressure from the articular surface to the deep zone. [3,9] In addition, static and dynamic osmotic pressure gradients also occur in many other contexts from soil sciences, [10] to colloidal sciences, [11] water treatment, [12] energy generation, [13] material engineering, [14] and membrane filtration. [15] In contrast to molecular motors,t he functions of which have been studied in great detail, [16] much less is known about the potential roles of osmotic pressures,e specially in animal tissues.O ne of the reasons is the lack of in situ probes for osmotic strength sensing.S uch sensors would not only be important in biological contexts but also in all situations where osmotic processes need to be monitored in-operando from biology to physical chemistry and to engineering.T he goal of the present work is to develop al ocal probe for spatiotemporal monitoring of osmotic stresses through light microscopy.…”

“…Within our muscles,m olecular motors are responsible for animal locomotion, but they also mediate cell motility and adhesion and many other cellular processes.I n plants,f orce generation and organ movement is often linked to turgor pressure,w hich is generated by another type of chemo-mechanical conversion based on osmotic gradients. These are known for more than hundred years [1] to be critical for av ariety of cell functions, [2] living tissue organizations [3] and vital activities. [4] Osmotic pressure is recognized as an important biophysical cue as it can induce cell volume changes,w hich in turn activate osmoregulatory responses [4] and can determine,f or example,s tem cell fate.…”