Antibacterial nanocomposites containing amorphous calcium phosphate and silver nanoparticles with different filler levels

Published

May 7, 2012

Author(s)

Lei Cheng, Michael D. Weir, Hockin H. Xu, Joseph M. Antonucci, Nancy Lin, Sheng Lin-Gibson, Sarah M. Xu, Xuedong Zhou

Abstract

A dental composite containing amorphous calcium phosphate nanoparticles (NACP) was developed that released high levels of calcium (Ca) and phosphate (PO4) ions and possessed acid neutralization capability. There has been little study on incorporation of antibacterial agents into calcium phosphate composites. The objective of this study was to investigate the effect of silver nanoparticle (NAg) mass fraction in NACP nanocomposite on mechanical properties and microcosm biofilm response for the first time. NACP nanoparticles of 116 nm were synthesized via a spray-drying technique. NAg was synthesized using Ag 2-ethylhexanoate salt and 2-(tert-butylamino)ethyl methacrylate, yielding NAg particles of 2.7 nm that were dispersed in the resin. Five NACP nanocomposites were fabricated with NAg mass fractions of 0 %, 0.028 %, 0.042 %, 0.088 %, 0.175 %, respectively. Mechanical properties of NACP nanocomposite containing 0 % to 0.042 % of NAg matched those of a commercial composite without antibacterial activity. Live/dead staining of biofilms showed complete coverage with primarily live bacteria on commercial composite, while there were increasingly more dead bacteria with more NAg in the NACP nanocomposite. Colony-forming unit (CFU) counts for total microorganisms, total Streptococci, and mutans Streptococci for NACP nanocomposite with 0.042 % NAg were about 1/4 those of a commercial composite. Lactic acid production on NACP nanocomposite with 0.042 % NAg was about 1/3 that on commercial composite. In conclusion, novel NACP-NAg nanocomposites were developed with good mechanical properties and strong antibacterial activity which increased with NAg content. NACP nanocomposite with 0.042 % NAg greatly reduced biofilm metabolic activity, CFU counts and lactic acid production, without compromising load-bearing properties. The NACP-NAg nanocomposite is promising for restorations with remineralizing and antibacterial capabilities.

Citation

Journal of Biomedical Materials Research Part B-Applied Biomaterials

Volume

100

Issue

5

Pub Type

Journals

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DOI Link

Keywords

Antibacterial nanocomposite, amorphous calcium phosphate nanoparticles, silver nanoparticles, microcosm oral plaque biofilm, stress-bearing, tooth caries inhibition, Dentistry

Citation

Cheng, L. , Weir, M. , Xu, H. , Antonucci, J. , Lin, N. , Lin-Gibson, S. , Xu, S. and Zhou, X. (2012), Antibacterial nanocomposites containing amorphous calcium phosphate and silver nanoparticles with different filler levels, Journal of Biomedical Materials Research Part B-Applied Biomaterials, [online], https://doi.org/10.1002/jbm.b.32709 (Accessed October 11, 2025)