Synthesis & Antimicrobial Efficacy of Magnetic Silica - - PowerPoint PPT Presentation

Kyoungja Woo

Synthesis & Antimicrobial Efficacy of Magnetic Silica Microspheres Decorated with AgNPs

10th U.S.-Korea Nano Forum, Boston, MA, Oct 15-16, 2013

Need eds s for V Virus s Rem emoval Sy Syst stem (Air, r, W Water) er)

OUTBREAKS OF VIRAL INFECTION !

SOCIAL D DEMAND

Nano C Convergent Materi erials T s Tech.

Motiv ivatio ion o n of the P e Project

AgNP NP int nterac actio ion w n with b bac acterial ial c cel ells

1) Release Ag+ and generate ROS 2) Interact with membrane protein 3) Accumulate in the cell membrane 4) Enter into the cell

• J. Nanopart. Res. (2010) 12:1531

AgNPs The smaller, the better

AgNP NP inter eraction w with m h microb

• bial

al m membranes anes

The AgNPs bind to the gp120 knobs (cysteine location) of HIV virus

Journal of Nanobiotechnology 2005, 3:6

AgNP(<10 nm) & HIV-I Degradation of the membrane Structure

Journal of Colloid and Interface Science 2004, 275, 177

AgNP(~12 nm) & E. Coli b d

Major challenges in practical utilization of AgNPs

• 1. Aggregation of AgNPs
• 2. Environmental release of AgNPs

* The smaller, the better?

Organi anic P Polymer er-AgN gNP Composit ite

Polysulfone ultrafiltration membrane impregnated with AgNP (Membrane fabrication: 1 15% PS PSf, 10% 10% P PVP, 75% 75% N NMP, , 0. 0.9% AgNP) without AgNP with AgNP After filtration of 0.4 L/cm2, 10% AgNP loss !

Water Research 2009, 43, 715

▪ Magne gnetic h hybr brid c d colloid d d decor

• rated

d with AgN gNP (AgN gNP@MHC HC)

Inorgani anic Super erparam amag agnet etic AgNP NP Composit ite

Inorgani anic Super erparam amag agnet etic AgNP@ P@MH MHC

• S. Coverage:

8.8% 25% 18%

Inorgani anic Super erparam amag agnet etic Ag/Au@M @MHC

XPS a PS analysi sis o s of A Ag/Ag@MH MHC

Fe

3

O

4

Silica AP

+ + + + + + + + + + +

nAg30@MHC

Ag 3d5/2, 3d3/2 N 1s

AP@MHC + Ag+ AP@MHC

▪ Repe peatedl dly u y usable noble m e met etal nanoc nocatalyst yst com

• mpo

posi site

Cat atal alytic P Property o

• f A

Ag/Au@M @MHC

ka = 0.095/min TOF(nAg/Au@MHC) = 3.8×10-3/s TOF(chitosan-AgNP5nm) = 0.97×10-3/s

• Sci. Rep. 2013, 3, 1497, Woo

Ag/Au@MHC

Ant ntim imicr icrobia ial ef effec ects o

• f AgNP@MHC
• E. Coli

li CN13 Bacteriophage MS2

E.coli CN13+Ag30@MHC as-prepared E.coli CN13 E.coli CN13+Ag30@MHC @30 min E.coli CN13+Ag30@MHC @60 min

AgNP@MHC bites away bacteria

AgNP@MHC chemisorbs viruses (Bacteriophage MS2)

Tyr230 Asn228 His181 Arg226 Glu213 Asp94 Arg226 Glu213 His181 Asn228 Asp94 Tyr230

Influenza viral HA structure (interactions at the dimer interface)

from Prof. Kyunghyun Kim in Korea University

Mechani nist stic study f udy for antimicrobi bial e effects o s of AgN gNP (30 n nm) m)

(A) (B) (C)

1 h 1 h 1 d 1 d

Scale-up synthesis for practical application

TEOS

Acknowledgment

Fund: Ministry of Science, ICT & Future Planning through NRF of Korea (GNT program), KIST People: Dr. Hye Hun Park (KIST),

• Ms. Mihwa Seo (KIST),
• Dr. Jae-Pyoung Ahn (KIST),
• Mr. SungJun Park (SNU),
• Prof. GwangPyo Ko (SNU)
• Mr. Yoonhaeng Cho (Yonsei U.)
• Prof. Jeongho Hwang (Yonsei U.)

Thank you !