Beyond temperature: controlling collagen fibrillogenesis under physiological conditions via interaction with cucurbit[7]uril

An enzyme-proof glycan glue for extracellular matrix to ameliorate intervertebral disc degeneration

Intervertebral disc degeneration (IDD) remains a global healthcare challenge. Here, by analyzing clinical samples, we discover the loss of milk fat globule-EGF factor 8 (MFG-E8) from the nucleus pulposus (NP) tissue-along with increased enzymatic breakdown of glycosaminoglycans (GAGs)-as an overlooked factor for IDD development. Repairing the degraded NP extracellular matrix (ECM) with a structurally-mimicking glycan glue to enrich MFG-E8 may counter the degeneration. Accordingly, we synthesize a glucomannan octanoate (GMOC) with robust resistance to ECM-cleaving enzymes, which forms assemblies with MFG-E8 to maintain a healthy NP cell phenotype. GMOC injected into the degenerated intervertebral disc enriches MFG-E8 in situ, leading to NP tissue regeneration in a rat and a rabbit model, which represent two clinical scenarios of pre-surgical intervention and post-surgical regeneration of IDD, respectively. In summary, we report enriching MFG-E8 in ECM with a glycan glue as a mechanism to promote NP regeneration for IDD treatment.

Macrocyclic Cavitand β-Cyclodextrin Inhibits the Alcohol-induced Trypsin Aggregation

Trypsin, the most abundant pancreatic protein, aids in protein digestion by hydrolysis and exhibits aggregation propensity in presence of alcohol which can further lead to pancreatitis and eventually pancreatic cancer. Herein, by several experimental and theoretical approaches, we unearth the inhibition of alcohol-induced aggregation of Trypsin by macrocyclic cavitand, β-cyclodextrin (β-CD). β-CD interacts with the native protein and shows inhibitory effect in a dose dependent manner. Moreover, the secondary structures and morphologies of Trypsin in presence of β-CD also clearly emphasize the inhibition of fibril formation. From Fluorescence Correlation Spectroscopy, we observed an enhancement in diffusion time of Nile Red with ~ 2.5 times increase in hydrodynamic radius, substantiating the presence of fibrillar structure. Trypsin also shows reduction in its functional activity due to alcohol-induced aggregation. Our simulation data reports the probable residues responsible for fibril formation which was validated by molecular docking studies.