Evaluation of amoxicillin loaded montmorillonite nanocomposite as drug delivery system in dental calcium phosphate bone cement; in vitro study

Abstract

Objective: This study aims to modify tri-calcium phosphate cement (CPC) with an experimentally prepared amoxicillin loaded Montmorillonite nanoclay (AMX-MMT), and evaluate it regarding drug release, cytotoxicity and antibacterial activity. Methods. MMT was prepared via sol-gel methodology, then loaded with AMX, and added to CPC in three concentrations (2.5, 5 and 7.5 wt%). Characterization was performed using FTIR, XRD, DLS, and TEM. Drug encapsulation efficiency (EE%) and invitro drug release was also evaluated. Cytotoxicity was performed using MTT Assay, while antibacterial test was evaluated using agar well diffusion method against Streptococcus mutans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. One-way ANOVA followed by Tukey's post hoc test (p ≤ 0.05) were utilized to analyze data. Results: Characterization results revealed successful preparation of AMX-MMT. EE% was calculated to be 70 %. In vitro drug release showed a controlled release of AMX-MMT, and group 7.5 % showed the fastest drug release among the modified CPC groups, while group 2.5 % showed the slowest release. All tested groups showed cell viability higher than 95 %, however, group 7.5 wt% had statistically significant lower cell viability at 24 h with signs of apoptosis. AMX-MMT-CPC demonstrated antibacterial activity on both Escherichia coli and Streptococcus mutants on all the tested concentrations (5–40 mg/ml). However, both Pseudomonas aeruginosa and Staphylococcus aureus didn't show inhibition zone at concentration of 5 mg/ml. Conclusion: The formulated AMX-MMT drug delivery nanocomposite can be successfully added to calcium phosphate bone cement up to 7.5 wt% exhibiting controlled release of AMX, high antibacterial activity without causing cytotoxic effects.