Use of crosslinkers to inactivate dentin MMPs

Area of Science:

• Biomaterials Science
• Dental Research
• Biochemistry

Background:

• Demineralized dentin matrix harbors endogenous matrix metalloproteinases (MMPs) that can degrade collagen.
• Uncontrolled MMP activity compromises the integrity and longevity of dental biomaterials and restorations.
• Effective inhibition of MMPs is essential for improving the durability of dentin-based treatments.

Purpose of the Study:

• To evaluate the efficacy of various collagen crosslinkers in reducing endogenous MMP activity in demineralized dentin.
• To determine the optimal pretreatment time (1 or 5 minutes) for crosslinker application.
• To assess the impact of crosslinkers on MMP levels and activity using multiple analytical techniques.

Main Methods:

• Six collagen crosslinkers (glutaraldehyde, riboflavin/UVA, riboflavin-5-monophospate/UVA, sumac berry extract, grape seed extract, curcumin) were tested.
• Demineralized dentin beams were pretreated for 1 or 5 minutes, with untreated beams serving as controls.
• Matrix-bound MMP activity was assessed using generic MMP assays, in situ zymography, gelatin zymography, and multiplex bead technology for MMP-8, MMP-2, and MMP-9.

Main Results:

• Crosslinker pretreatment significantly reduced MMP activity by 21-70%, while untreated samples showed increased activity (up to 84%).
• Zymography confirmed reduced gelatinolytic activity and lower extractable total protein content in treated samples.
• Multiplex analysis revealed decreased release of MMP-8, MMP-2, and MMP-9 following crosslinker application.

Conclusions:

• Collagen crosslinkers, even with short pretreatment times (1 minute), effectively inactivate endogenous protease activity in demineralized dentin.
• The efficacy of crosslinkers is source-dependent, highlighting the need for tailored approaches.
• These findings support the use of crosslinkers to enhance the stability of demineralized dentin in dental applications.