Damaged extracellular matrix collagen fibrils

Damaged extracellular matrix (ECM) collagen fibrils represent a pathological state of the most abundant structural protein in the human body, characterized by the unwinding of the native triple-helical structure into disordered single-stranded alpha chains (Li & Yu, 2013). This denaturation occurs as a result of mechanical stress, thermal damage, or excessive proteolytic activity by matrix metalloproteinases (MMPs) during active tissue remodeling (Hwang et al., 2017). While intact collagen is largely inert to many binding partners, damaged fibrils expose "cryptic" epitopes and allow for the hybridization of specific molecules, making them a unique target for diagnostic and therapeutic intervention (Bennink et al., 2018). This target is particularly relevant in oncology, where tumor invasion requires extensive ECM degradation, and in fibrotic diseases where collagen turnover is dysregulated (Xu et al., 2001). Current drug development focuses on Collagen Hybridizing Peptides (CHPs) and monoclonal antibodies that selectively bind these denatured regions to deliver imaging contrast agents or localized therapy, thereby minimizing off-target effects on healthy, intact connective tissues. By specifically recognizing the unfolded state of collagen, these agents can provide high-contrast imaging of disease activity and potentially deliver potent payloads directly to the site of injury or malignancy.

Other names

Denatured collagenDegraded collagenUnwound collagen triple helixCryptic collagen epitopesGelatinized collagen

Triple helix hybridization with denatured collagen strands and binding to cryptic epitopes exposed by proteolysis (Li & Yu, 2013; Xu et al., 2001).