RESUMO
AIM: To assess the effects of 2-hydroxyethyl methacrylate (HEMA) on proliferation and migration of human pulp cells, as well as on matrix metalloproteinase (MMP-2 and MMP-9) expression in human odontoblast-like cells, contributing to the goal of determining the relationship between resin materials and MMP activity in pulp-dentine complexes. METHODOLOGY: Dental pulp cell cultures were established from pulp tissue of human teeth extracted for orthodontic purposes. Pulp cell differentiation was characterized in the presence of dentine sialophosphoprotein, bone sialoprotein and alkaline phosphatase by reverse transcription polymerase chain reaction. MMP activity was assessed by gelatine zymography with media containing HEMA. Cell viability was evaluated using methyl thiazolyl tetrazolium assay for 24-72 h. Cell migration was tested using Transwell migration assay. Western blotting was used to visualize MMP expression with the nontoxic HEMA concentrations (0-400 µg mL-1 ) for 48 h. RESULTS: Pulp cell proliferation decreased with HEMA exposure in a time- and concentration-dependent manner. HEMA concentrations ≤400 µg mL-1 did not induce changes in cell viability at 48 h (P < 0.05). Pulp cells were induced to differentiate into odontoblast-like cells in media containing 5 mg mL-1 ascorbic acid and 10 mmol L-1 ß-sodium glycerophosphate for 3-4 weeks. After incubation with HEMA, dose-dependent inhibition was observed; HEMA had a strong inhibitory effect on MMP activity. Compared with the control group, cell migration and MMP expression were inhibited significantly with increasing HEMA concentration at noncytotoxic doses (P < 0.05). CONCLUSIONS: Cell viability was not affected at HEMA concentrations ≤400 µg mL-1 . Within this range, HEMA inhibited MMP-2 and MMP-9 expression and activity, which may protect against type I collagen degradation effectively during dentine adhesive procedures.