Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 13, 235-249
eCollection

Antimicrobial Activity of Silver Nanoparticles Encapsulated in Poly- N-isopropylacrylamide-based Polymeric Nanoparticles

Affiliations

Antimicrobial Activity of Silver Nanoparticles Encapsulated in Poly- N-isopropylacrylamide-based Polymeric Nanoparticles

Muhammad Qasim et al. Int J Nanomedicine.

Abstract

In this study, we analyzed the antimicrobial activities of poly-N-isopropylacrylamide (pNIPAM)-based polymeric nanoparticles encapsulating silver nanoparticles (AgNPs). Three sizes of AgNP-encapsulating pNIPAM- and pNIPAM-NH2-based polymeric nanoparticles were fabricated. Highly stable and uniformly distributed AgNPs were encapsulated within polymeric nanoparticles via in situ reduction of AgNO3 using NaBH4 as the reducing agent. The formation and distribution of AgNPs was confirmed by UV-visible spectroscopy, transmission electron microscopy, and inductively coupled plasma optical emission spectrometry, respectively. Both polymeric nanoparticles showed significant bacteriostatic activities against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria depending on the nanoparticle size and amount of AgNO3 used during fabrication.

Keywords: antimicrobial activities; pNIPAM; silver nanoparticles; surface charge.

Conflict of interest statement

Disclosure The authors report no conflicts of interest in this work.

Figures

Figure 1
Figure 1
Average sizes of poly-N-isopropylacrylamide (pNIPAM) nanoparticle groups G1–G3 (A), and average sizes of pNIPAM-NH2 nanoparticle groups G1–G3 (B).
Figure 2
Figure 2
Schematic diagram of the synthesis of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM)-based nanoparticle platforms. Abbreviations: APS, ammonium persulfate; RT, room temperature; SDS, sodium dodecyl sulfate.
Figure 3
Figure 3
(A) Cytotoxicity of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM) nanoparticle groups and (B) AgNP encapsulated pNIPAM-NH2 nanoparticle groups against human adipose stem cells after 48 h. Note: *p-value (p<0.05) indicates a significant difference as compared with the control (ie, absorbance from the cell treated with no nanoparticles). Abbreviation: NS, non significant.
Figure 4
Figure 4
(A) UV-visible spectra of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM) nanoparticle groups G1–G3, and (B) Ag peak absorbance at 435 nm in gels containing 5 and 10 mM concentrations of AgNO3.
Figure 5
Figure 5
(A) UV-visible spectra of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM)-NH2 nanoparticle groups G1–G3, and (B) Ag peak absorbance at 435 nm in gels containing 5 and 10 mM concentrations of AgNO3.
Figure 6
Figure 6
Representative transmission electron microscopy micrographs of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM) nanoparticles fabricated with two different concentrations of silver salt, (A) 5 mM AgNO3 and (B) 10 mM AgNO3. Note: The difference in retention of silver in nanocomposite after washing was confirmed by inductively-coupled plasma optical emission spectrometry analysis.
Figure 7
Figure 7
Representative transmission electron microscopy micrographs of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM)-NH2 nanoparticles fabricated with two different concentrations of silver salt, (A) 5 mM AgNO3 and (B) 10 mM AgNO3. Note: The difference in retention of silver in nanocomposite after washing was confirmed by inductively-coupled plasma optical emission spectrometry analysis.
Figure 8
Figure 8
X-ray photoelectron spectroscopy spectra of poly-N-isopropylacrylamide (pNIPAM) (top) and pNIPAM-NH2 (bottom), condition G1. Notes: The curved-fitted spectra (black) are superimposed on the experimental data. The peaks of each coordination species are labeled and shown within the curve-fitted spectra.
Figure 9
Figure 9
Antimicrobial activities of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM) nanogel size groups G1–G3 against Escherichia coli (E.coli). Notes: (A) Liquid culture of E. coli with pNIPAM G1. (B) Liquid culture of E. coli with pNIPAM G2. (C) Liquid culture of E. coli with pNIPAM G3. (D) Solid culture of E. coli with control (pure growth), pNIPAM G1–G3 and average diameter of zone of inhibition (mm) graph.
Figure 10
Figure 10
Antimicrobial activities of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM)-NH2 nanogel size groups G1–G3 against Escherichia coli (E. coli). Notes: (A) Liquid culture of E. coli with pNIPAM-NH2 G1. (B) Liquid culture of E. coli with pNIPAM-NH2 G2. (C) Liquid culture of E. coli with pNIPAM-NH2 G3. (D) Solid culture of E. coli with control (pure growth), pNIPAM-NH2 G1–G3 and average diameter of zone of inhibition (mm) graph.
Figure 11
Figure 11
Antimicrobial activities of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM) nanogel size groups G1–G3 against Staphylococcus aureus (S. aureus). Notes: (A) Liquid culture of S. aureus with pNIPAM G1. (B) Liquid culture of S. aureus with pNIPAM G2. (C) Liquid culture of S. aureus with pNIPAM G3. (D) Solid culture of S. aureus with control (pure growth), pNIPAM G1–G3 and average diameter of zone of inhibition (mm) graph.
Figure 12
Figure 12
Antimicrobial activities of silver nanoparticle (AgNP)-encapsulated poly-N-isopropylacrylamide (pNIPAM)-NH2 nanogel size groups G1–G3 against Staphylococcus aureus (S. aurerus). Notes: (A) Liquid culture of S. aureus with pNIPAM-NH2 G1. (B) Liquid culture of S. aureus with pNIPAM-NH2 G2. (C) Liquid culture of S. aureus with pNIPAM-NH2 G3. (D) Solid culture of S. aureus with control (pure growth), pNIPAM-NH2 G1–G3 and average diameter of zone of inhibition (mm) graph.

Similar articles

See all similar articles

Cited by 2 PubMed Central articles

References

    1. Engemann JJ, Carmeli Y, Cosgrove SE, et al. Adverse clinical and economic outcomes attributable to methicillin resistance among patients with Staphylococcus aureus surgical site infection. Clin Infect Dis. 2003;36(5):592–598. - PubMed
    1. Zimmerli W, Ochsner PE. Management of infection associated with prosthetic joints. Infection. 2003;31(2):99–108. - PubMed
    1. Deyo RA, Nachemson A, Mirza SK. Spinal-fusion surgery – the case for restraint. N Engl J Med. 2004;350(7):722–726. - PubMed
    1. Lee JS, Murphy WL. Functionalizing calcium phosphate biomaterials with antibacterial silver particles. Adv Mater. 2013;25(8):1173–1179. - PMC - PubMed
    1. Pitout JD. The latest threat in the war on antimicrobial resistance. Lancet Infect Dis. 2010;10(9):578–579. - PubMed

MeSH terms

Feedback