Conclusion & Future Perspective
In summary, this in vitro study demonstrates, for the first time, that AuNPs coupled with a RF generator can be used for noninvasive and on-demand external triggering of drug carrier release from drug-eluting implants. TNT–Ti was used as the model substrate, but the approach is generic and can be applied for any other drug-eluting implants. Our results show that by using a short RF trigger to expose drug carriers loaded in TNT for 5 min, it is possible to achieve the release of indomethacin-loaded TPGS micelles from TNT in PBS with a high local drug dose (100–250 µg) and a total release of 80–100% over a short timeframe, ranging from 25 min to 2 h. The method is safe, noninvasive, convenient and instantly effective.
Although the method is demonstrated using two examples, water-insoluble drugs (indomethacin) and drug carriers (TPGS micelles), it is a generic approach and there is no limitation for other therapeutics (e.g., antibiotics, anti-inflammatories and anticancer drugs) to be applied, in which these bioactive compounds can be locally released to address emergency conditions where immediate release of high concentrations of a therapeutic agent is required at unsolicited or unpredicted times. In the future, by selecting a series of controllable parameters, such as the conditions for RF signaling, location or distance of RF source from the implant, the time of RF exposure and the amount of loaded drug or AuNPs in the implant, one can adjust the DDS for specific therapeutic applications in orthopedics, stents, wound healing or cancer therapies. This technology has the upperhand over the current persisting methods, as by using RF combined with TNT implants, the trigger can be applied remotely and painlessly leading to increased patient compliance.
Financial & competing interests disclosure
The authors received financial support from the Australian Research Council (FT 110100711 and DP 120101680) and the University of Adelaide, School of Chemical Engineering for this work. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.
Ethical conduct of research
The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.
Nanomedicine. 2014;9(8):1263-1275. © 2014 Future Medicine Ltd.