Carbon nanodots as molecular scaffolds for development of antimicrobial agents

• Main Authors: Maria, Ngu-Schwemlein, Suk, Fun Chin, Ryan, Hileman, Chris, Drozdowski, Clint, Upchurch, April, Hargrove
• Format: E-Article
• Language: English
• Published: Elsevier Ltd. 2016
• Subjects: TP Chemical technology
• Online Access: http://ir.unimas.my/id/eprint/12986/1/Carbon%20nanodots%20as%20molecular%20scaffolds%20for%20development%20%28abstract%29.pdf; http://ir.unimas.my/id/eprint/12986/; https://www.scopus.com/record/display.uri?eid=2-s2.0-84979054298&origin=resultslist&sort=plf-f&src=s&st1=Carbon+nanodots+as+molecular+scaffolds+for+development+of+antimicrobial+agents&st2=&sid=B1B05F08DE62EFCA7D3CF5AD04BE357C.wsnAw8kcdt7IPYLO0V48gA%3a80&s; http://dx.doi.org/10.1016/j.bmcl.2016.02.047

We report the potential of carbon nanodots (CNDs) as a molecular scaffold for enhancing the antimicrobial activities of small dendritic poly(amidoamines) (PAMAM). Carbon nanodots prepared from sago starch are readily functionalized with PAMAM by using N-ethyl-N0-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Electron microscopy images of these polyaminated CNDs show that they are approximately 30–60 nm in diameter. Infrared and fluorescence spectroscopy analyses of the water-soluble material established the presence of the polyamidoaminated moiety and the intrinsic fluorescence of the nanodots. The polyaminated nanodots (CND-PAM1 and CND-PAM2) exhibit in vitro antimicrobial properties, not only to non-multidrug resistant bacteria but also to the corresponding Gram-negative multidrug bacteria. Their minimum inhibitory concentration (MIC) ranges from 8 to 64 lg/mL, which is much lower than that of PAMAM G1 or the non-active PAMAM G0 and CNDs. Additionally, they show synergistic effect in combination with tetracycline or colistin. These preliminary results imply that CNDs can serve as a promising scaffold for facilitating the rational design of antimicrobial materials for combating the ever-increasing threat of antibiotic resistance. Moreover, their fluorescence could be pertinent to unraveling their mode of action for imaging or diagnostic applications.