Graduate Category: Health Degree Seeking: PhD Abstract ID# 1794 ...
Graduate Category: Health Degree Seeking: PhD Abstract ID# 1794 One-pot Growth of Silver Nanoparticles on Self-Assembled PEGylated Rosette Nanotubes: Design, Preparation, and Antimicrobial Properties Yiwen Fan and Hicham Fenniri* Department of Chemical Engineering, Northeastern University, Boston, MA,02115 [email protected], [email protected]
Synthesis of G^C
Abstract
AgNPs on PEGylated RNTs
[4] Base Aldehyde
A
With the emerging antibiotics resistance problems for the treatment of bacterial infectious diseases, researchers are constantly seeking alternative treatment modalities. For instance, silver nanoparticles (AgNPs) have been widely utilized as effective antimicrobials due to their long-term antibacterial activity, low cytotoxicity and lower bacterial resistance. Recent studies have demonstrated that the bactericidal effects are strongly dependent on the size and dispersion of AgNPs. Therefore, preparing AgNPs with defined dimensions is an important aim to enhance the reactivity of nanoparticles with bacteria. We report here that self-assembled supramolecular rosette nanotubes (RNTs) consisting polyethylene glycol spontaneously reduce the silver ions and subsequently generate stable monodisperse AgNPs in aqueous solution. We have also found that the RNTs/AgNPs system has antimicrobial activity and significantly low cytotoxicity toward human dermal fibroblast cells.
B
60 50
Numbers
40 30 20 10 0 0.6-0.9
RNTs exhibit high stability as a result of the extensive H-bond network and the inter-rosette π-π stacking interactions. The functional side-groups covalently attached to the GC motif offer important physical and chemical properties as well as diverse applications of the RNTs.[1]
1.8-2.1
2.1-2.4
2.4-2.7
Cytotoxicity Study of AgNPs on PEGylated RNTs Synthesis scheme of GC aldehyde (a). POCl3, DMF, reflux, 18h, 70%; (b). Allyamine, CH2Cl2, 78℃, 4h, 80%; (c). Methylamine, THF, 0℃, 5h, 74%; (d). Benzyl alcohol, NaH, THF, reflux, 22h, 74%; (e). DMAP, TEA, Boc2O, THF, rt, 18h, 88%; (f). HONH2, pyridine, 60℃, 1h, 92%; (g). TFAA, TEA, THF, reflux, 2h, 85%; (h). Cl3CCONCO, CH2Cl2, rt, 6h; (i). NH3, MeOH, rt, 18h, 81%; (j). DMAP, TEA, Boc2O, THF, rt, 18h, 100%; (k). NMO, OsO4, H2O, Acetone, rt, 18h, 100%; (l). CH2Cl2, NaIO4, H2O, rt, 18h, 65%.
***
***
**
140% 120%
* 100%
Viability
synthetic DNA hybrid molecule GC motif in which Watson-Crick pairing takes place between the guanine side of the GC motif and its cytosine side.
1.5-1.8
(A) TEM image of AgNPs on PEGylated RNTs in water (1 mg/mL); and (B) AgNPs size distribution, diameter of AgNPs: 1.28 ± 0.46 nm, measured by Image-J.
motif[4]:
Rosette nanotubes (RNTs) are hierarchically self-assembled from
1.2-1.5
Diameter /nm
160%
Background
0.9-1.2
80%
PEG-RNT/AgNPs AgNO3
60% 40%
* 20%
Synthesis of PEG with amine termini
***
***
***
0% 9.3µM
18.6µM
93µM
186µM
Silver Amount
Human dermal fibroblast (HDF) 24 hours cytotoxicity. Cells were seeded at 20,000 cells/cm2. Values are mean ± SD, N=3. *p
Synthesis of G^C
Abstract
AgNPs on PEGylated RNTs
[4] Base Aldehyde
A
With the emerging antibiotics resistance problems for the treatment of bacterial infectious diseases, researchers are constantly seeking alternative treatment modalities. For instance, silver nanoparticles (AgNPs) have been widely utilized as effective antimicrobials due to their long-term antibacterial activity, low cytotoxicity and lower bacterial resistance. Recent studies have demonstrated that the bactericidal effects are strongly dependent on the size and dispersion of AgNPs. Therefore, preparing AgNPs with defined dimensions is an important aim to enhance the reactivity of nanoparticles with bacteria. We report here that self-assembled supramolecular rosette nanotubes (RNTs) consisting polyethylene glycol spontaneously reduce the silver ions and subsequently generate stable monodisperse AgNPs in aqueous solution. We have also found that the RNTs/AgNPs system has antimicrobial activity and significantly low cytotoxicity toward human dermal fibroblast cells.
B
60 50
Numbers
40 30 20 10 0 0.6-0.9
RNTs exhibit high stability as a result of the extensive H-bond network and the inter-rosette π-π stacking interactions. The functional side-groups covalently attached to the GC motif offer important physical and chemical properties as well as diverse applications of the RNTs.[1]
1.8-2.1
2.1-2.4
2.4-2.7
Cytotoxicity Study of AgNPs on PEGylated RNTs Synthesis scheme of GC aldehyde (a). POCl3, DMF, reflux, 18h, 70%; (b). Allyamine, CH2Cl2, 78℃, 4h, 80%; (c). Methylamine, THF, 0℃, 5h, 74%; (d). Benzyl alcohol, NaH, THF, reflux, 22h, 74%; (e). DMAP, TEA, Boc2O, THF, rt, 18h, 88%; (f). HONH2, pyridine, 60℃, 1h, 92%; (g). TFAA, TEA, THF, reflux, 2h, 85%; (h). Cl3CCONCO, CH2Cl2, rt, 6h; (i). NH3, MeOH, rt, 18h, 81%; (j). DMAP, TEA, Boc2O, THF, rt, 18h, 100%; (k). NMO, OsO4, H2O, Acetone, rt, 18h, 100%; (l). CH2Cl2, NaIO4, H2O, rt, 18h, 65%.
***
***
**
140% 120%
* 100%
Viability
synthetic DNA hybrid molecule GC motif in which Watson-Crick pairing takes place between the guanine side of the GC motif and its cytosine side.
1.5-1.8
(A) TEM image of AgNPs on PEGylated RNTs in water (1 mg/mL); and (B) AgNPs size distribution, diameter of AgNPs: 1.28 ± 0.46 nm, measured by Image-J.
motif[4]:
Rosette nanotubes (RNTs) are hierarchically self-assembled from
1.2-1.5
Diameter /nm
160%
Background
0.9-1.2
80%
PEG-RNT/AgNPs AgNO3
60% 40%
* 20%
Synthesis of PEG with amine termini
***
***
***
0% 9.3µM
18.6µM
93µM
186µM
Silver Amount
Human dermal fibroblast (HDF) 24 hours cytotoxicity. Cells were seeded at 20,000 cells/cm2. Values are mean ± SD, N=3. *p
