title: Carbon nanodots as molecular scaffolds for development of antimicrobial agents.
abstract: 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-N'-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Electron microscopy images of these polyaminated CNDs show that they are approximately 30-60nm 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 64μg/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.
authors.affiliation: Department of Chemistry, Winston-Salem State University, Winston-Salem, NC 27110, USA. Electronic address: Schwemleinmn@wssu.edu.
authors.forename: Maria
authors.initials: M
authors.lastname: Ngu-Schwemlein
authors.affiliation: Department of Chemistry, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia.
authors.forename: Suk Fun
authors.initials: SF
authors.lastname: Chin
authors.affiliation: Department of Chemistry, Winston-Salem State University, Winston-Salem, NC 27110, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Hileman
authors.affiliation: Department of Chemistry, Winston-Salem State University, Winston-Salem, NC 27110, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Drozdowski
authors.affiliation: Department of Chemistry, Winston-Salem State University, Winston-Salem, NC 27110, USA.
authors.forename: Clint
authors.initials: C
authors.lastname: Upchurch
authors.affiliation: Department of Chemistry, Winston-Salem State University, Winston-Salem, NC 27110, USA.
authors.forename: April
authors.initials: A
authors.lastname: Hargrove
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D002244:Carbon / Q000737:chemistry* / Q000494:pharmacology*; D050091:Dendrimers / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D013388:Succinimides / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D050091:Dendrimers; C104700:PAMAM Starburst; D013388:Succinimides; D002244:Carbon; C001426:N-hydroxysuccinimide
keywords: Antimicrobial activities; Carbon nanodots; Molecular scaffold; PAMAM; Synergism