Composite PLGA/AgNpPGA/AscH Nanospheres with Combined Osteoinductive, Antioxidative, and Antimicrobial Activities

Abstract

The global rise in the resistance of pathogens to conventional antibiotics has created an intensive search for alternative materials with antimicrobial properties. This study is performed with an intention to investigate the combined effects of poly(L-glutamic acid)-capped silver nanoparticles (AgNpPGA) and ascorbic acid (AscH) encapsulated within freeze-dried poly(lactide-co-glycolide) (PLGA) nanospheres to obtain a nanomaterial with simultaneous osteoinductive, antioxidative, and prolonged antimicrobial properties. The influence of PLGA/AgNpPGA/AscH particles on (i) viability and super-oxide production of human umbilical vein endothelial cells in vitro, (ii) morphology and expression of osteogenic markers in osteoblastic MC3T3-E1 cells in vitro, and (iii) antimicrobial activity against a Gram-positive bacterium, methicillin-resistant Staphylococcus aureus, and a Gram-negative bacterium, Escherichia coli, was investigated. PLGA/AgNpPGA/AscH nanoparticles showed a superior and extended antibacterial activity against both types of bacteria. The nanoparticles appeared to be capable of delivering ascorbate to the cells, which was evidenced by the significant decrease in the level of superoxides in human umbilical vein endothelial cells and which could have a therapeutic potential in preventing oxidative stress. PLGA/AgNpPGA/AscH nanoparticles had a positive effect on MC3T3-E1 osteoblastic cells in vitro, promoting: (i) an intimate contact with the cells and preservation of their healthy morphologies; (ii) unreduced cell viability; and (iii) multiple-fold upregulation of two osteogenic markers: osteocalcin and type I procollagen. It is concluded that PLGA/AgNpPGA/AscH nanospheres present a promising new material for the treatment of infections and use in wound dressings and other prophylactic applications.

45S5Bioglass®-based scaffolds coated with selenium nanoparticles or with poly(lactide-co-glycolide)/selenium particles: Processing, evaluation and antibacterial activity

“…Metal and metalloid nanoparticles are used in various biomedical applications. For example, silver, gold and platinum are some of the alternative inorganic materials with antimicrobial properties [25]. Selenium nanoparticles have also been reported to possess antibacterial as well as antiviral activities [26].…”

Polymeric micro- and nanoparticles for controlled and targeted drug delivery

“…Spherical nanoparticles of the poly (D,L-lactide-co-glycolide) (PLGA) were produced using physicochemical method with solvent/non-solvent systems (Stevanović et al 2007a;Stevanović et al 2007b;Stevanović et al 2007c). The encapsulation of the ascorbic acid, folic acid, silver nanoparticles (AgNp) or AgNp together with ascorbic acid in the PLGA polymer matrix have bee successfully performed by homogenization of water and organic phases (Stevanović et al2007a,b;Stevanović et al 2008a, b;Stevanović et al 2009c;Stevanović et al 2012b;Stevanović et al 2013;Stevanović et al 2014)).…”

The Application of Nanotechnology for Implant Drug Release

“…Core-shell encapsulation may be used if the polymer processing solvent is incompatible with the drug to be encapsulated while promoting bone healing [ 123 ]. Similarly, Stevanovic et al showed that silver nanoparticles and the anti-oxidant/osteogenic factor ascorbic acid could be coincorporated into PLGA nanoparticles which could then kill E. coli and MRSA as well as promote bone formation [ 124 ], although in this case incorporation into medical devices was only suggested not tried. He et al showed that polyethylenimine nanopolyplexes containing plasmids encoding vascular endothelial growth factor (VEGF) and fi broblast growth factor (FGF) could be incorporated into fi bers scaffolds made of PEG-PLA [ 125 ].…”