Title: 0261 - Protein-repellent Nanocomposite With Remineralization Capabilities and Rechargeable Calcium Phosphate Ions


Yousif Al Dulaijan (Presenter)
University of Maryland, Baltimore, MD 21201, USA

Mary Anne Melo, University of Maryland Dental School, Baltimore, MD 21201, USA
Michael Weir, University of Maryland, Baltimore, MD 21201, USA
Thomas Oates, University of Maryland, Baltimore, MD 21201, USA
Hockin Xu, University of Maryland Dental School, Baltimore, MD 21201, USA


Objectives: The incorporation of nanoparticles of amorphous calcium phosphate (NACP) and 2-methacryloyloxyethyl phosphorylcholine (MPC) into composite showed improved caries-inhibition, remineralization, and protein-repellent effects. There has been no report on the rechargeability of nanocomposite containing NACP-MPC. Our objectives were to develop rechargeable NACP-MPC composite, and investigate the effects of MPC and NACP on mechanical properties, protein-repellency, antibacterial effects, calcium (Ca) and phosphate (P) ion release and rechargeability.

Methods: Nanocomposites were synthesized with 0 (control), 1.5%, and 3% of MPC by mass. MPC, NACP (20%) and glass particles (50%) were mixed into pyromellitic glycerol dimethacrylate and ethoxylated bisphenol A dimethacrylate. Mechanical properties were measured in three-point flexure. Protein adsorption onto the composites was measured by a micro bicinchoninic acid method. A human saliva microcosm model was used to grow biofilms. Colony-forming units (CFU), live/dead, metabolic activity, and lactic acid were determined. Ca and P release, recharge and re-release were measured.

Results: Nanocomposites with 1.5% MPC (70.67±4.5) and 3% MPC (71.2±7.8) had flexural strength in MPa similar to those without MPC (72.3±10.2) and the commercial control (70.2±9.3). The incorporation of MPC reduced protein adsorption (p<0.05). MPC groups inhibited biofilm metabolic activity, lactic acid and CFU, compared to controls (p<0.05). Experimental control, 1.5% MPC and 3% MPC showed high Ca ion release in mmol/L of (3.85±0.04), (4.06±0.02), and (4.30±0.03), and P ions (1.15±0.01), (1.26±0.01), and (1.34±0.01), respectively, at 70 days (p>0.1). After the 3rd recharge cycle, Ca release was (0.82±0.01) for control, (0.78±0.01) for 1.5% MPC and (0.78±0.01) for 3% MPC, and P ions were (0.25±0.001), (0.24±0.001), and (0.26±0.001), respectively (p>0.1).

Conclusions: Addition of MPC into nanocomposite achieved protein-repellent and antibacterial capabilities without compromising the mechanical properties, ion release, and rechargeability. All nanocomposites had high and durable Ca and P re-release which did not decrease with increasing the number of recharge cycles.

Student Presenter

This abstract is based on research that was funded entirely or partially by an outside source:
NIH R01 DE17974 (HX) and a Seed Grant (HX) from the University of Maryland School of Dentistry

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: N/A

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