pH-dependent delivery of chlorhexidine from PGA grafted mesoporous silica nanoparticles at resin-dentin interface

Abstract

Background A low pH environment is created due to the production of acids by oral biofilms that further leads to the dissolution of hydroxyapatite crystal in the tooth structure significantly altering the equilibrium. Although the overall bacterial counts may not be eradicated from the oral cavity, however, synthesis of engineered anti-bacterial materials are warranted to reduce the pathogenic impact of the oral biofilms. The purpose of this study was to synthesize and characterize chlorhexidine (CHX)-loaded mesoporous silica nanoparticles (MSN) grafted with poly-L-glycolic acid (PGA) and to test the in vitro drug release in various pH environments, cytotoxicity, and antimicrobial capacity. In addition, this study aimed to investigate the delivery of CHX-loaded/MSN-PGA nanoparticles through demineralized dentin tubules and how these nanoparticles interact with tooth dentin after mixing with commercial dentin adhesive for potential clinical application. Results Characterization using SEM/TEM and EDX confirmed the synthesis of CHX-loaded/MSN-PGA. An increase in the percentage of drug encapsulation efficiency from 81 to 85% in CHX loaded/MSN and 92–95% in CHX loaded/MSN-PGA proportionately increased with increasing the amount of CHX during the fabrication of nanoparticles. For both time-periods (24 h or 30 days), the relative microbial viability significantly decreased by increasing the CHX content (P < 0.001). Generally, the cell viability percentage of DPSCs exposed to MSN-PGA/Blank, CHX-loaded/MSN, and CHX-loaded/MSN-PGA, respectively was > 80% indicating low cytotoxicity profiles of experimental nanoparticles. After 9 months in artificial saliva (pH 7.4), the significantly highest micro-tensile bond strength value was recorded for 25:50 CHX/MSN and 25:50:50 CHX/MSN-PGA. A homogenous and widely distributed 50:50:50 CHX-loaded/MSN-PGA nanoparticles exhibited excellent bonding with the application of commercially available dentin adhesive. Conclusions A pH-sensitive CHX release response was noted when loaded in MSN grafted PGA nanoparticles. The formulated drug-loaded nanocarrier demonstrated excellent physicochemical, spectral, and biological characteristics. Showing considerable capacity to penetrate effectively inside dentinal tubules and having high antibacterial efficacy, this system could be potentially used in adhesive and restorative dentistry.

Combined Release of Antiseptic and Antibiotic Drugs from Visible Light Polymerized Biodegradable Nanocomposite Hydrogels for Periodontitis Treatment

“…Until today, several studies have shown a change in the release of CHX as a result of pH change, and more articles can be found as examples for the pH-dependent properties of the PGA, but the combination of these systems can provide the base of novel treatment concepts for patients with moderate or severe periodontitis [ 6 , 42 , 45 , 46 ]. The combination of drugs to increase the effectiveness and decrease the necessary amount of the applied medicines is a long-standing endeavor.…”

pH‐receptive chlorhexidine‐loaded poly‐L‐glycolic acid platform delivery approach to stabilize adhesive‐orthodontic interface

“…CHXloaded PLGA nanoparticles demonstrated a typical peak of Raman scattering at 638, 802, 1040, 1127, and 1446 cm À1. [25] The Raman spectrum at 1446 cm À1 for CHX-loaded/MSN-PGA is suggestive of anti-symmetric vibration from the lactic unit corresponded to CH 2 deformation which is confined to a lower intensity in CHXloaded/MSN groups. The assignments at 1040 and 1127 cm À1 correspond to CH 3 Rocking and CH 2 wagging.…”

Graphene functionalized with nanosilver particle‐modified methacrylate‐based bonding agent improves antimicrobial capacity and mechanical strength at tooth orthodontic bracket interface

“…After seeding of cells, 100 μl of culture medium was removed and thereafter, 20 μl of MTT reagent solution (2 mg/ml) was added to each experimental adhesive disc and incubated for 4 h at 37°C in 5% CO 2 atmosphere, followed by adding 200 μl/well of dimethyl sulfoxide (DMSO, Sigma‐Aldrich, St. Louis, MO, USA) under gentle shaking for 15 min. The absorbance was measured at 570 nm using a microplate spectrophotometer reader (Bio‐Rad, Model 680 XR, CA), and the cell viability was evaluated after 0, 24, 48, and 72 h. [ 28 ]…”