The water soluble zinc based metal-organic frameworks (Zn-MOFs) as potential inhibitors for collagen fibrillogenesis.

Small molecules ranging from organic to inorganic systems have been reported as stabilizing agents for collagen. Various transition metal complexes have been utilized as tanning agent. However, as per the environmental norms issued by various regulatory agencies, the presence of certain metals such as Cr, Fe, Al, Zr and Ti in leather has been restricted to minimal amount (50 ppm), an unsurmountable task. To overcome the above issue and find an alternative tanning system, here in this study, we have reported the interaction of two water-soluble zinc-based metal-organic frameworks (MOFs), i.e., ZnPV (1) and ZnPA (2), with collagen using various spectroscopic techniques. Fibrillation kinetics studies showed that a significant delay in fibril formation with Zn-MOFs treated collagen was observed compared to the collagen untreated/ treated with individual ligands and metal salt. Circular dichroism studies show that at a low weight ratio (1:0.2 and 1:1::Collagen: MOF), no perturbation in the triple helical structure was observed, while at higher weight ratio (1:4), denaturation of collagen occurs. FT-IR studies showed that no perturbation was observed in the amide backbone in MOF-treated collagen. Differential scanning calorimetric data revealed that both Zn-MOFs increased the thermal denaturation temperature by 22 ± 2 °C compared to the collagen treated with individual entities. The viscosity of collagen rises with the increase in the concentration of Zn-MOFs. To the best of our knowledge, this is the first report on the use of the metal-organic framework as a stabilizing agent for collagen structure and might help in exploring the MOFs as potential tanning agents.

Gene expression analysis in patients with traumatic anterior shoulder instability suggests deregulation of collagen genes.

Shoulder dislocation occurs in 1-2% of the population. Capsular deformation is a key factor in shoulder dislocation; however, little is known about capsule biology. We evaluated, for the first time in literature, the expression of COL1A1, COL1A2, COL3A1 and COL5A1 in the antero-inferior, antero-superior and posterior regions of the glenohumeral capsule of 31 patients with anterior shoulder instability and eight controls. The expression of collagen genes was evaluated by quantitative reverse transcription-PCR. The expression of COL1A1, COL3A1 and the ratio of COL1A1/COL1A2 were increased in all three portions of the capsule in patients compared to controls (p < 0.05). COL1A2 expression was upregulated in the antero-superior and posterior sites of the capsule of patients (p < 0.05). The ratio of COL1A2/COL3A1 expression was reduced in capsule antero-inferior and posterior sites of patients compared to controls (p < 0.05). In the capsule antero-inferior site of patients, the ratios of COL1A1/COL5A1, CO1A2/COL5A1 and COL3A1/COL5A1 expression were increased (p < 0.05). In patients, COL1A1/COL5A1 was also increased in the posterior site (p < 0.05). We found deregulated expression of collagen genes across the capsule of shoulder instability patients. These molecular alterations may lead to modifications of collagen fibril structure and impairment of the healing process, possibly with a role in capsular deformation.