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.
