Hyaluronic acid slows down collagen membrane degradation in uncontrolled diabetic rats

Abstract

Aim To examine the in vitro biokinetics of hyaluronic acid (HA) from a collagen membrane (CM) and to evaluate the in vivo effect of immersion of the CM in HA solution on its degradation in streptozotocin (STZ)‐induced diabetes conditions in a rat calvaria subcutaneous model. Background CM degradation is accelerated in uncontrolled diabetic rats. Immersion of CM in HA has been suggested to decrease their resorption rate without interfering with their tissue integration and structural degradation. However, it is unknown to what extent CM degradation may be influenced by its immersion in HA solution under a condition mimicking a medically compromised situation with an increased inflammatory level such as diabetes. Materials and Methods CMs were soaked in cross‐linked HA. Protein adsorption and the HA release were quantified by ELISA. Diabetes was induced in sixteen rats, while 16 healthy rats served as control. CM was prepared and labeled prior to implantation with Biotin. Seventeen CM were immersed in HA and 17 CM in PBS. In each animal, one test or one control disk was implanted. In order to compare the collagen content, two similar non‐implanted CM were used as baseline. Fourteen days after surgery, thirty‐two animals were sacrificed. The entire calvaria including the skin above, was chemically fixed, decalcified, and embedded in paraffin. Five‐μm‐thick sections were analyzed histologically and histomorphometrically using H&E and avidin‐peroxidase staining. Results The in vitro results demonstrated that the CM adsorbed roughly 80% of the total HA content. After 10 days, 36.3% of the initial HA remained on the CM. The in vivo results demonstrated that diabetes significantly reduced the thickness of the CM, while HA had a significant effect on keeping the membrane thickness. HA increased the residual collagen content in the diabetic group (P < 0.0001) but no such effect was observed in the healthy group. Conclusion Immersion of CM in HA prior to the implantation delays membrane degradation in uncontrolled diabetic compared with normoglycemic rats.

Accelerated degradation of collagen membranes in type 1 diabetic rats is associated with increased expression and production of several inflammatory molecules

“…[26][27][28][29] In support of our contention that DM results in enhancement of inflammation/collagenolysis around the membranes, we found that immersion of the membranes in tetracycline (TC) or hyaluronic acid (HA) prior to implantation mitigated their resorption in diabetic rats, probably because of the anticollagenolytic/anti-inflammatory properties, respectively, of these additives. [26][27][28][29] Therefore, the present study was performed to compare the local expression and production of several pro-inflammatory molecules at the membrane implantation site between diabetic and normoglycemic rats and provide a better understanding of the molecules that drive the exaggerated inflammation shown histologically in and around the membranes. We analyzed the presence of IL-6, TNF , MMP-9, MIP-1 , MIP-2 , and MIF, representing different aspects of the inflammatory process, namely cytokines, chemokines, and MMPs.…”

“…These time points were selected based on our previous studies showing accelerated membrane resorption in this model. [26][27][28][29] Dermal tissues were dissected away leaving the periosteum undisturbed and the membrane including overlying and underlying tissues was retrieved. Six samples from each group were immediately frozen in liquid nitrogen and then transferred to −80 • C for RNA/protein isolation.…”

“…This analysis was done only to confirm the reduced thickness and increased presence of inflammatory cells in and around the membranes of the diabetic rats, as described in our previous studies. [26][27][28][29] The thickness of the residual biotin-avidin stained membrane was determined with a ×10 objective in an Olympus microscope as an average of six measurements in each section.…”

“…We have recently shown that DM similar to type 1, induced in rats via injection of streptozotocin, results in an accelerated degradation of collagen membranes implanted subcutaneously. [26][27][28][29] This rapid degradation was associated with an increased inflammatory infiltrate in and around the membranes and specifically with a greater number of putative M1 macrophages (CD-68 positive cells). [26][27][28][29] In support of our contention that DM results in enhancement of inflammation/collagenolysis around the membranes, we found that immersion of the membranes in tetracycline (TC) or hyaluronic acid (HA) prior to implantation mitigated their resorption in diabetic rats, probably because of the anticollagenolytic/anti-inflammatory properties, respectively, of these additives.…”

“…[26][27][28][29] This rapid degradation was associated with an increased inflammatory infiltrate in and around the membranes and specifically with a greater number of putative M1 macrophages (CD-68 positive cells). [26][27][28][29] In support of our contention that DM results in enhancement of inflammation/collagenolysis around the membranes, we found that immersion of the membranes in tetracycline (TC) or hyaluronic acid (HA) prior to implantation mitigated their resorption in diabetic rats, probably because of the anticollagenolytic/anti-inflammatory properties, respectively, of these additives. [26][27][28][29] Therefore, the present study was performed to compare the local expression and production of several pro-inflammatory molecules at the membrane implantation site between diabetic and normoglycemic rats and provide a better understanding of the molecules that drive the exaggerated inflammation shown histologically in and around the membranes.…”