Green Synthesis of Nanosilver-Loaded Hydrogel Nanocomposites for Antibacterial Application

Authors: D. Berdous, H. Ferfera-Harrar

Abstract:

Superabsorbent polymers (SAPs) or hydrogels with three-dimensional hydrophilic network structure are high-performance water absorbent and retention materials. The in situ synthesis of metal nanoparticles within polymeric network as antibacterial agents for bio-applications is an approach that takes advantage of the existing free-space into networks, which not only acts as a template for nucleation of nanoparticles, but also provides long term stability and reduces their toxicity by delaying their oxidation and release. In this work, SAP/nanosilver nanocomposites were successfully developed by a unique green process at room temperature, which involves in situ formation of silver nanoparticles (AgNPs) within hydrogels as a template. The aim of this study is to investigate whether these AgNPs-loaded hydrogels are potential candidates for antimicrobial applications. Firstly, the superabsorbents were prepared through radical copolymerization via grafting and crosslinking of acrylamide (AAm) onto chitosan backbone (Cs) using potassium persulfate as initiator and N,N’-methylenebisacrylamide as the crosslinker. Then, they were hydrolyzed to achieve superabsorbents with ampholytic properties and uppermost swelling capacity. Lastly, the AgNPs were biosynthesized and entrapped into hydrogels through a simple, eco-friendly and cost-effective method using aqueous silver nitrate as a silver precursor and curcuma longa tuber-powder extracts as both reducing and stabilizing agent. The formed superabsorbents nanocomposites (Cs-g-PAAm)/AgNPs were characterized by X-ray Diffraction (XRD), UV-visible Spectroscopy, Attenuated Total reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Inductively Coupled Plasma (ICP), and Thermogravimetric Analysis (TGA). Microscopic surface structure analyzed by Transmission Electron Microscopy (TEM) has showed spherical shapes of AgNPs with size in the range of 3-15 nm. The extent of nanosilver loading was decreased by increasing Cs content into network. The silver-loaded hydrogel was thermally more stable than the unloaded dry hydrogel counterpart. The swelling equilibrium degree (Q) and centrifuge retention capacity (CRC) in deionized water were affected by both contents of Cs and the entrapped AgNPs. The nanosilver-embedded hydrogels exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria. These comprehensive results suggest that the elaborated AgNPs-loaded nanomaterials could be used to produce valuable wound dressing.

Keywords: Antibacterial activity, nanocomposites, silver nanoparticles, superabsorbent hydrogel.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1127182

References:

[1] M.J. Zohuriaan-Mehr, K. Kabiri, “Superabsorbent polymer materials”, Iran. Polym. J., vol. 17, pp. 451-477, 2008.
[2] H. Ferfera-Harrar, N. Aiouaz, N. Dairi, “Synthesis and Properties of Chitosan-Graft-Polyacrylamide/Gelatin Superabsorbent Composites for Wastewater Purification”, World Academy of Science, Engineering and Technology Inter. J. Chem., Molecular Nuclear Mater. Metallurgical Eng., vol.9, pp.757–764, 2015.
[3] C.Y. Chang, B. Duan, J. Cai, L.N. Zhang, “Superabsorbent hydrogels based on cellulose for smart swelling and controllable delivery”, Eur. Polym. J., vol. 46, pp. 92-100, 2010.
[4] M. Rai, A. Yadav, A. Gade, “Silver nanoparticles as a new generation of antimicrobials”, Biotech. Advances, vol 27, pp.76–83, 2009.
[5] Y. Murali Mohan, K. Vimala, V. Thomas, K. Varaprasad, B. Sreedhar, S.K. Bajpai, K. Mohana Raju, “Controlling of silver nanoparticles structure by hydrogel networks”, J. Colloid Interf. Sci., vol. 342, pp. 73–82, 2010.
[6] B. Boonkaew, P. Suwanpreuksa, L. Cuttle, P. M. Barber, P. Supaphol, “Hydrogels Containing Silver Nanoparticles for Burn Wounds Show
[7] Antimicrobial Activity without Cytotoxicity”, J. Appl. Polym. Sci., vol.131, pp.40215-40225, 2014.
[8] H. Bożena Tyliszczak, K. Pielichowski, “Novel hydrogels containing nanosilver for biomedical applications - synthesis and characterization”, J. Polym. Res., vol. 20, pp. 191-196, 2013.
[9] K. Varaprasad, Y. Murali Mohan, K. Vimala, K. Mohana Raju, “Synthesis and characterization of hydrogel–silver nanoparticle–curcumin composites for wound dressing and antibacterial application”, J. Applied Polym. Sci., vol. 121, pp.784–796, 2011.
[10] H. Mellegard, S.P. Strand, B.E. Christensen, P.E. Granum, S.P. Hardy, “Antibacterial activity of chemically defined chitosans: Influence of molecular weight, degree of acetylation and test organism”, Int. J. Food Microbiol., vol. 148, pp.48-54, 2011.
[11] H. Ferfera-Harrar, N. Aiouaz, N. Dairi, A. S. Hadj-Hamou, “Preparation of chitosan-g-poly(acrylamide)/montmorillonite superabsorbent polymer composites: Studies on swelling, thermal, and antibacterial properties”, J. Appl. Polym. Sci., vol.131, pp. 39747-39750, 2014.
[12] K. Vimala, Y.M. Mohan, K. Varaprasad, N. Reddy, S. Narayana Ravindra, N. S. Naidu, “Fabrication of curcumin encapsulated chitosan–PVA silver nanocomposite films for improved antimicrobial activity”, J. Biomaterials and Nanobiotechnology, vol. 2, pp.55–64, 2011.
[13] K. Shameli Mansor Bin Ahmad, A. Zamanian, P. Sangpour, P. Shabanzadeh, Y. Abdollahi, M. Zargar, “Green biosynthesis of silver nanoparticles using Curcuma longa tuber powder”, Int. J. Nanomedicine, vol. 7, pp. 5603–5610, 2012.
[14] H. Ferfera-Harrar, N. Aiouaz, N. Dairi, “Environmental-sensitive chitosan-g-polyacrylamide/carboxymethylcellulose superabsorbent composites for wastewater purification I: synthesis and properties”, Polym. Bull., vol.73, pp.815-840, 2016.
[15] J. Krstic, J. Spasojevic, A. Radosavljevic, A. Peric-Grujic, M. Duric, Z. K. arevic-Popovic, S. Popovic, “In vitro Silver Ion Release Kinetics from Nanosilver/Poly(vinyl alcohol) Hydrogels Synthesized by Gamma Irradiation”, J. Appl. Polym. Sci., vol.131, pp.40321-40335, 2014.
[16] T. Jayaramudu, G. M. Raghavendra, K. Varaprasad, R. Sadiku, K. Ramam, K. Mohana Raju, “Iota-Carrageenan-based biodegradable Ag 0 nanocomposite hydrogels for the inactivation of bacteria”, Carbohyd. Polym., vol. 95, pp.188–194, 2013.
[17] Y. Zhou, Y. Zhao, L. Wang, L. Xu, M. Zhai, S. Wei, “Radiation synthesis and characterization of nanosilver/gelatin/carboxymethyl chitosan hydrogel”, Radiation Phy. Chem., vol. 81, pp.553–560, 2012.
[18] S.K. Murthy, Y. Murali Mohan, K. Varaprasad, B. Sreedhar, K. Mohana Raju, “First successful design of semi-IPN hydrogel–silver nanocomposites: A facile approach for antibacterial application”, Colloid. Interf. Sci., vol. 318, pp.217-224, 2008.
[19] M. Pereda, A.G. Ponce, N.E. Marcovich, R.A. Ruseckaite, J.F. Martucci, “Chitosan-gelatin composites and bi-layer films with potential antimicrobial activity”, Food Hydrocolloid, vol. 25, pp.1372-1381, 2011.
[20] C. L. Gallant-Behm, H. Q. Yin, S. Liu, J. P. Heggers, R. E. Langford, M. E. Olson, et al., “Comparison of in vitro disc diffusion and time kill-kinetic assays for the evaluation of antimicrobial wound dressing efficacy”, Wound Repair and Regeneration, vol.13, pp. 412–421, 2005.
[21] N. Liu, X.G. Chen, H.J. Park, C.G. Liu, C.S. Liu, X.H. Meng, L.J. Yu, “Effect of MW and concentration of chitosan on antibacterial activity of Escherichia coli”, Carbohydr. Polym., vol. 64, pp.60-65, 2006.
[22] W. K., Jung, H. C. Koo, K. W. Kim, S. Shin, S. H. Kim, Y. H. Park, “Antibacterial activity and mechanism of action of the silver ion in Staphylococcus aureus and Escherichia coli”. Appl. Environ. Microbiol., vol. 74, pp. 2171-8, 2008.