Development of antimicrobial peptide-loaded hydrogels as potential scaffolds for pulp-dentine complex regeneration: A comparative study.

Abstract

Introduction: As a recently developed treatment modality, regeneration of the pulp-dentin-like complex via tissue engineering (TE) approaches is the focus of considerable attention. The persistence of bacteria within the root canal spaces is well known as the major challenge of dental pulp regeneration. Antimicrobial peptides (AMPs) are short peptides with inhibitory activities against a broad spectrum of microorganisms.

Methods: In the present study, antimicrobial hydrogels based on two photo-reactive biopolymers, i.e. collagen methacrylate (ColMA) and chitosan methacrylate (ChitMA), and containing two different AMPs, i.e. LLKKK18 and Tet213, were used to develop a potential scaffold with antimicrobial and regenerative features.

Results: The incorporation of AMPs had no significant effect on the physical, mechanical, rheological, and morphological properties of the new systems. The optimized concentration of LLKKK18 and Tet213 had appropriate antimicrobial activity against Gram-positive Enterococcus fæcalis (E. fæcalis) and did not exhibit any cytotoxicity to stem cells from the apical papilla (SCAP) encapsulated within the hydrogels compared to the control group without AMPs. The presence of AMPs also significantly promoted migration and differentiation of SCAP. In the AMP-loaded groups, greater levels of calcified nodules deposition, ALP, COL I, DSPP, DMP1, and VEGF mRNA gene expression, and COL I and DSPP protein expression were observed.

Conclusions: The results indicated the potential of engineered antimicrobial ColMA/ChitMA hydrogels for application in TE-based strategies to regenerate the pulp-dentin complex.