Antibacterial Performance of a PCL–PDMAEMA Blend Nanofiber-Based Scaffold Enhanced with Immobilized Silver Nanoparticles

Abstract

In the present study, nanofiber meshes (NFs), composed of polycaprolactone and poly[(2-dimethylamino)ethyl methacrylate] at 80/20 and 50/50 PCL/PDMAEMA blend ratios, were obtained through electrospinning. Silver nanoparticles (AgNPs) formed in situ were then immobilized on NF surfaces through adsorption processes at different pHs. It was possible to observe that the amount of NF-AgNPs can be tuned by changing the pH of AgNPs immobilization and the PCL/PDMAEMA ratio in the blend. The neat NF and NF-AgNPs were characterized with respect to their morphology and mechanical properties. The effects of AgNPs on the antibacterial activities and cytotoxicity of meshes were also evaluated. The antibacterial performance of such NF was improved by the presence of AgNPs. The NF-AgNPs presented good antibacterial effect against S. aureus and partial toxicity against E. coli and P. aeruginosa. Also, compared with neat PCL/PDMAEMA the NF-AgNPs presented lower cytotoxicity against VERO cells, showing their potential for applications in tissue engineering for different types of cell growth.

A Readily Accessible Functional Nanofibrous Membrane for High‐Capacity Immobilization of Ag Nanoparticles and Ultrafast Catalysis Application

“…Moreover, AgNPs‐PEI/PDA/NFM exhibits completely different surface feature: lower hydrophilicity derived from the citrate stabilization. The citrate contains abundant carbonyl groups as shown in Figure S4a in the Supporting Information, which is prone to induce the protonation of amino and imino group and further attract each other via coulomb interaction …”

“…In detail, the above mentioned interaction can be assigned to Lewis acid–base interaction mainly involving electrostatic interaction between PEI and citrate‐capped Ag NPs, which is illustrated from the relation between the adsorption capability and pH as shown in Figure d. The zeta potential of citrate capped Ag NPs changed from about 24 to −60 mV (Figure S9a, Supporting Information), which is consistent with the reported result that the deprotonation level of citrate varies from 25% to about 75% with pH increase from 3 to 11 . Besides, in the same pH range, the protonation level of PEI on NFM reduces from about 75% to 5% .…”

“…Besides, in the same pH range, the protonation level of PEI on NFM reduces from about 75% to 5% . Since the electrical potential matching between citrate decorated on Ag NPs and PEI attached on the membrane is the key factor governing their adsorption behavior, intermediate pH conditions (pH = 7) was selected for the preparation of AgNPs‐PEI/PDA/NFM. The case of pH 3 and 5 caused a higher proportion of unprotonated citrate covering on Ag NPs that further leads to the size increase of Ag NPs aggregated in colloids as shown in Figure S9a in the Supporting Information.…”

Aluminum plasmonic nanoshielding in ultraviolet inactivation of bacteria

“…This will allow for controlling the UV shielding efficiency using various techniques which were developed for designing the plasmonic substrates based on Ag and Au. For example, the arrays of plasmonic nanostructures with desired properties can be fabricated 56 – 60 . Hot electron generation in Al nanocrystals may provide an alternative mechanism of the bacterial inactivation and will be investigated in the future 61 .…”

Renewable Fabric Surface-Initiated ATRP Polymerizations: Towards Mixed Polymer Brushes

“…Consequently, the yielded fibers turned purplish in color which is consistent with the typical Au NPs plasmonic color, demonstrating the successful in situ synthesis of Au NPs (Figure 4). Since the Au NPs could be used as bioactive materials, the antibacterial activity of Au NPs@PA-g-[(PMMA 164 -H)-mixed brushes-PDMAEMA 63 -Br] was analyzed by estimation the resistance of growth for E. coli reflected by the formation of inhibition halo around the sample [46]. In comparison to unmodified PA, PA-g-[(PMMA 164 -H)-mixed brushes-PDMAEMA 63 -Br], and a blank sample of PA loaded with Au NP (Figure 4b-d), which showed no antibacterial activity, the growth of E. coli in the case of Au NPs@PA-g-[(PMMA 164 -H)-mixed brushes-PDMAEMA 63 -Br] was significantly inhibited in the zone with a diameter of 2 mm (Figure 4a).…”