Synthesis and Characterization of Methacrylate-Functionalized Betulin Derivatives as Antibacterial Comonomer for Dental Restorative Resins

Abstract

Secondary caries is the primary cause of composite restoration failures, resulting from marginal leakage and bacterial accumulation in the oral environment. Antibacterial dental composites, especially antibacterial monomers, have emerged as a promising strategy to inhibit secondary caries, which is pivotal to prolonging the lifespan of dental restorations. In this work, monomethacrylate- and dimethacrylate-functionalized betulin derivatives (M1Bet and M2Bet) were synthesized via an esterification reaction and served as antibacterial comonomers to develop novel dental resin formulations, in which M1Bet and M2Bet were incorporated to partially or completely replace bisphenol A glycerolate dimethacrylate (Bis-GMA). The control resin was a mixture based on Bis-GMA and tri­(ethyleneglycol) dimethacrylate (TEGDMA) with a weight ratio of 50:50 (5B5T). The effect of the resin compositions and the chemical structures of M1Bet and M2Bet on the rheology behavior, optical property, polymerization kinetics, mechanical performance, cell viability, and antibacterial activity of dental resins were systematically investigated. Among all materials, the 1M2Bet4B5T resin with 10 wt % substitution of Bis-GMA by M2Bet exhibited comparable viscosity, higher light transmittance, improved degree of conversion, and mechanical properties compared with 5B5T. After incubation for 24 h, this optimal resin also possessed the best antibacterial activity against Streptococcus mutans, which had a significantly lower bacterial concentration (1.53 × 109 CFU/mL) than 5B5T (9.03 × 109 CFU/mL). Introducing betulin-based comonomers into dental resins is a potential strategy to develop antibacterial dental materials without sacrificing physical–mechanical properties.

Synthesis and Fabrication of a Betulin-Containing Polyolefin Electrospun Fibrous Mat for Antibacterial Applications

“…Interestingly, the viabilities of either cell type for two electrospun fibrous mats were greater than ∼92% on average, indicating their excellent biocompatibility for potential biomedical applications. These results are in consistent with previous reports. , …”

“…It is found that both mono- and dual-functionalized betulin monomers exhibit less dense colonies than betulin, suggesting they are capable of inhibiting the growth of bacteria. Betulin moieties in polymeric materials can maintain their biological activity and contribute to the antimicrobial properties of the polymers. , Herein, the antimicrobial properties of the fibrous mats were characterized using colony formation counting with E. coli (Gram-negative bacteria), S. aureus (Gram-positive bacteria), and C. albicans (fungi), and the results are shown in Figure . It was found that the count for viable colonies of E. coli decreased for both mats after 24 h. Interestingly, the colony numbers dramatically decreased for S. aureus and C. albicans , indicating a better antibacterial activity against Gram-positive bacteria and fungus.…”

“…These results are in consistent with previous reports. 43,44 Antimicrobial Activity. As reported in our previous work, methacrylated betulin derivatives were prepared and used as antibacterial monomers for dental resins.…”

“…As reported in our previous work, methacrylated betulin derivatives were prepared and used as antibacterial monomers for dental resins. 44 It is found that both mono-and dual-functionalized betulin monomers exhibit less dense colonies than betulin, suggesting they are capable of inhibiting the growth of bacteria. Betulin moieties in polymeric materials can maintain their biological activity and contribute to the antimicrobial properties of the polymers.…”

Inserting Menthoxytriazine into Poly(ethylene terephthalate) for Inhibiting Microbial Adhesion

“…In recent years, stereochemical strategies have received special attention because of their safe, nontoxic, nonrelease, and long-term advantages. − The theoretical basis of this antibacterial strategy is the selective recognition by microorganisms of chiral terpenoid molecules (borneol or menthol). − The chiral terpenoid molecule-grafted surfaces and polymers exhibited excellent antimicrobial (bacterial and fungal) properties. − The related studies have shown that the antimicrobial adhesion performance based on stereochemistry is closely related to the number of grafted chiral molecules, , indicating that the increase of the modification density of stereochemical terpene molecules will help to improve the antimicrobial adhesion properties of modified PET. Menthol is a typical terpenoid molecule whose modified materials have emerged as candidates for antimicrobial adhesion. , Compared with borneol, menthol is more likely to produce various derivatives due to its low spatial resistance and high reactivity. , Therefore, skeleton modification of PET with the menthol moiety should be an appropriate method to impart antimicrobial adhesion properties to PET.…”