Plasma-initiated graft polymerization as an immobilization platform for metal free Russian propolis ethanol extracts designed specifically for biomaterials

Abstract

The antibacterial and anti-biofilm activities of propolis have been intensively reported. However, the application of this folk remedy as a means to prevent biomedical implant contamination has yet to be completely evaluated. In response to the significant resistant and infectious attributes of biofilms, biomaterials engineered to possess specific chemical and physical properties were immobilized with metal free Russian propolis ethanol extracts (MFRPEE), a known antibacterial agent. The results obtained from this study begin to examine the application of MFRPEE as a novel alternative method for the prevention of medical and biomedical implant infections. When constructed under specific experimental conditions, immobilized biomaterials showed excellent stability when subjected to simulated body fluid and fetal bovine serum. The ability of immobilized biomaterials to specifically target pathogens (both Gram-positive and Gram-negative biofilm forming bacteria), while promoting tissue cell growth, renders these biomaterials as potential candidates for clinical applications.

Plasma-Initiated Graft Polymerization of Acrylic Acid onto Fluorine-Doped Tin Oxide as a Platform for Immobilization of Water-Oxidation Catalysts

“…The plasma-initiated graft polymerization technique has a chemically different mechanism in comparison to conventional polymerization techniques. This uniqueness stems from a free-radical polymerization reaction, which is initiated at the surface of the material without the need of chemical initiators. − By utilizing the “Grafting-From” approach, ion bombardment caused by a negative self-bias of the substrate creates reactive radical centers on the surface prior to polymerization. We have specifically chosen the “Grafting-From” method in this study as this approach is known to produce high-density grafting layers and high dispersity of the covalently attached surface polymers. − In the first step of surface modification, exposure of FTOs to argon plasma was evaluated under two experimental parameters: (1) argon plasma power and (2) argon plasma exposure time (Figure ).…”

“…The system was evacuated to 360 mTorr as argon gas was introduced to the chamber at a flow rate of 0.068 m 3 h –1 . The chamber pressure was subsequently maintained at 360 mTorr. − A radio frequency generator was supplied with a frequency of 13.56 MHz and had an output of up to 100 W for ca. 5 min.…”

“…Plasma technology has been utilized as an effective tool for the functionalization of polymeric material or synthesis of nanomaterials on transparent metal oxide films such as TiO 2 and to introduce desirable functional properties. − Plasma-modified FTO (fluorine doped tin-oxide) electrodes with cobalt selenide nanomaterials have been shown to improve the performance in dye-sensitized solar cells . This has been attributed to the increase in surface hydrophilicity, nanoparticle packing density, higher dye loading, and improved electron transport and reduced recombination.…”

“…Moreover, a polymer can be grafted onto a plasma-activated surface from a desired monomer resulting in self-assembled polymer brushes, which is known as the “Grafting-From” technique (Scheme ). − , Under the appropriate experimental conditions, reactive sites produced from the argon plasma treatment can initiate a free-radical polymerization reaction forming covalently bound polymer brushes onto the substrate upon addition of an unsaturated monomer. − , With the “Grafting-From” approach, polymer brush layers can be tailored to possess specific physical and chemical properties of nanostructures. − In addition, the grafting process can be easily controlled, cost effective, and eco-friendly as chemical initiators are not required. Some of us have previously reported the use of the argon plasma-initiated grafting technology for the construction of polymer brushes on biomaterial surfaces. − In the present work, we describe for the first time, the use of the “Grafting-From” approach for plasma-initiated graft polymerization of acrylic acid, which contains terminal carbon–carbon double bonds, onto FTO surfaces (Scheme ).…”

“… − , Under the appropriate experimental conditions, reactive sites produced from the argon plasma treatment can initiate a free-radical polymerization reaction forming covalently bound polymer brushes onto the substrate upon addition of an unsaturated monomer. − , With the “Grafting-From” approach, polymer brush layers can be tailored to possess specific physical and chemical properties of nanostructures. − In addition, the grafting process can be easily controlled, cost effective, and eco-friendly as chemical initiators are not required. Some of us have previously reported the use of the argon plasma-initiated grafting technology for the construction of polymer brushes on biomaterial surfaces. − In the present work, we describe for the first time, the use of the “Grafting-From” approach for plasma-initiated graft polymerization of acrylic acid, which contains terminal carbon–carbon double bonds, onto FTO surfaces (Scheme ). The design and construction of plasma-grafted poly­(acrylic acid) (PAA) assemblies in neutral aqueous solutions were further studied as a platform for the immobilization of underivatized benchmark Ru­(II) WOCs [Ru­(tpy) (bpy) (H 2 O)] 2+ ( Ru–Cat1 ; tpy = 2,2′:6′2″–terpyridine; bpy = 2,2′-bipyridine) , and [Ru­(Mebimpy) (bpy) (H 2 O)] 2+ ( Ru–Cat2 ; (Mebimpy = 2,6-bis­(1-methylbenzimidazol-2-yl)­pyridine) ,, in addition to the Ru­(II) polypyridine chromophore [Ru­(bpy) 3 ] 2+ ( Ru – C3 ) (Figure ).…”