A great new article from a collaboration between Dr. Jeff Weiss's lab and our founder, Dr. Michael Yu's lab at the University of Utah. The new Acta Biomaterialia paper explores at what point collagen denaturation occurs in tendons under mechanical strain and how tendon type influences the mechanism of failure. Researchers evaluated functionally distinct tendons using positional tendons (rat tail tendons) and energy-storing tendons (rat flexor digitorum ...
Fig. 1. Study overview. (A) Rat tail tendon fascicles were loaded in creep-fatigue to 40% of the ultimate tensile strength (UTS) until tissue failure. Incremental levels of fatigue were defined as the peak cyclic (creep) strain at 20, 50, and 80% of cycles to failure. (B) To label and quantify denatured collagen, we stained mechanically loaded fascicles with fluorescent CHP, which hybridizes to unfolded collagen ? chains. The amount of denatured collag...
Interesting work done in Jess Snedeker's lab was recently published in Matrix Biology. This work evaluated how microdamage to rat tail tendon fascicles influenced the ability of tenocytes (tendon fibroblasts) to aid in repair. This was probed by stretching fascicles up to 8% strain, using CHPs to stain for collagen damage, and then looking at the functional recovery of the fascicles up to 7 days after initial strain. They also looked at cell viability u...
New work being done by Dr. Robert Mauck's Lab at UPenn utilized CHPs to examine the effect that fatigue loading has on localized tissue mechanics. Their team discovered that although fatigue loading resulted in collagen kinking and denaturation, there was no difference in the local tissue modulus when compared to fresh controls. The image below shows how CHPs were used to visualize the collagen denaturation from fatigue loading and compare with the fres...
More exciting work using CHPs was just published in the Journal of Orthopaedic Surgery and Research! The authors examined the impact that high cholesterol had on the fibrillar architecture of the Achilles tendon in rabbits. By using B-CHPs they were able to see that rabbits with high cholesterol (hCH) had more damage to the fibrillar collagen than tissues taken from rabbits with normal cholesterol (nCH). The high-intensity regions running horizontally ...
A recently published paper in the Journal for Orthopaedic Research utilized F-CHP to develop a microplate assay for quantifying the amount of denatured collagen in samples. The authors compare their newly developed microplate assay with the hydroxyproline assay which is commonly used to determine the collagen content in a digest. They show that with the F-CHP, their new assay was just as accurate as the hydroxyproline assay but required much less time ...
Samuel Veres Lab published new work using CHP technology to evaluate the molecular damage caused to tendons that serve a positional function and tendons with energy-storing functions. Together with SHG and AFM they were able to rupture these tendons and saw that there is a difference in the molecular damage caused to the collagen triple helix depending on the type of tendon. This image shows a positional tendon that has been ruptured and shows short "n...
