Safety and efficacy of PLGA(Ag-Fe3O4)-coated dental implants in inhibiting bacteria adherence and osteogenic inducement under a magnetic field.
Introduction
The placement of dental implants is performed in a contaminated surgical field in the oral cavity, which may lead to implant failure. Bacterial adhesion and proliferation (Streptococcus mutans, Porphyromonas gingivalis) often lead to implant infections. Although Ag nanoparticles hold great promise for a broad spectrum of antibacterial activities, their runoff from dental implants compromises their antibacterial efficacy and potentially impairs osteoblast proliferation. Thus, this aspect remains a primary challenge and should be controlled.


Materials and methods
In this study, PLGA(Ag-Fe3O4) was modified on the implanted tooth surface and was characterized by transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The magnetic and antibacterial properties were also determined.


Results
Results showed that Ag successfully bonded with Fe3O4, and Ag-Fe3O4 not only exerted superparamagnetism but also exhibited antibacterial activity almost identical to silver nanoparticles (nano-Ag). The PLGA(Ag-Fe3O4) coating could significantly maintain the antibacterial activity and avoid bacterial adhesion to the implant. Compared with the blank control group, PLGA(Ag-Fe3O4) under magnetic field-coated samples had a significantly lower amount of colonized S. mutans (P<0.01). Osteoblast proliferation results showed that the coated samples did not exhibit cytotoxicity and could promote osteoblast proliferation as shown by MTT, alkaline phosphatase, and the nucleolar organizer region count.


Conclusion
We developed a novel Ag biologically compatible nanoparticle in this study without compromising the nano-Ag antibacterial activity, which provided continuous antibacterial action.
['Yang|Yaping|Y|', 'Ren|Shuangshuang|S|', 'Zhang|Xuan|X|', 'Yu|Yijun|Y|', 'Liu|Chao|C|', 'Yang|Jie|J|', 'Miao|Leiying|L|']
D000818:Animals D000900:Anti-Bacterial Agents D001422:Bacterial Adhesion D049109:Cell Proliferation D020099:Coated Materials, Biocompatible D015921:Dental Implants D005260:Female D005290:Ferric Compounds D019344:Lactic Acid D060526:Magnetic Fields D008297:Male D053768:Metal Nanoparticles D051379:Mice D008826:Microbial Sensitivity Tests D053761:Nanocomposites D010012:Osteogenesis D011100:Polyglycolic Acid D000077182:Polylactic Acid-Polyglycolic Acid Copolymer D016966:Porphyromonas gingivalis D017207:Rats, Sprague-Dawley D012834:Silver D013295:Streptococcus mutans
dental implants antibacterial property Ag-Fe3O4 PLGA