The Composites of Polyamide 12 and Metal Oxides with High Antimicrobial Activity

Abstract

The lack of resistance of plastic objects to various pathogens and their increasing activity in our daily life have made researchers develop polymeric materials with biocidal properties. Hence, this paper describes the thermoplastic composites of Polyamide 12 mixed with 1–5 wt % of the nanoparticles of zinc, copper, and titanium oxides prepared by a twin-screw extrusion process and injection moulding. A satisfactory biocidal activity of polyamide 12 nanocomposites was obtained thanks to homogenously dispersed metal oxides in the polymer matrix and the wettability of the metal oxides by PA12. At 4 wt % of the metal oxides, the contact angles were the lowest and it resulted in obtaining the highest reduction rate of the Escherichia coli (87%), Candida albicans (53%), and Herpes simplex 1 (90%). The interactions of the nanocomposites with the fibroblasts show early apoptosis (11.85–27.79%), late apoptosis (0.81–5.04%), and necrosis (0.18–0.31%), which confirms the lack of toxicity of used metal oxides. Moreover, the used oxides affect slightly the thermal and rheological properties of PA12, which was determined by oscillatory rheology, thermogravimetric analysis, and differential scanning calorimetry.

Nano-enabled antimicrobial thin films: design and mechanism of action

“… 54 They are processed into nanocomposite films in various designs and architectures; distributed in a polymer matrix, layered film structures and hybrids. 55 The frequently reported approach to fabricate antimicrobial MO x nanocomposite films is using a MO x /polymer layered structure, 56 including layer-by-layer (LBL) alternate deposition of MO x and polymer structures. 57 Due to the versatility of MO x nanomaterials, MO x -based antimicrobial thin films and membranes are extensively applicable in areas such as medical disinfection coatings, water treatment membranes and self-cleaning surfaces.…”

The Antifungal Fibers of Polyamide 12 Containing Silver and Metal Oxides

“…Briefly, C. albicans ref. strain 90028 ATCC (LGC Standard, Warsaw, Poland) at 1 × 10 5 CFU/mL of YEPD was incubated with the fibers (0.75 g) at 37 • C for 24 h [22]. Then, tenfold dilutions were plated on YEPD agar and the number of CFUs was counted for the tested and control (without any fillers) fibers.…”

“…Hence, the produced fibers were tested against example fungi-as they are the most difficult microorganisms to be destroyed. The results collected in Figure 10 show the standard quantitative procedure (AATCC TM100-2019, [22]) of the antifungal activity of the PA12 fibers containing metal oxides or silver nanoparticles vs. the PA12 control (without any fillers). Comparing the fibers with nAg (Figure 10a), it is seen that higher biological activity was obtained for the particles with a smaller size (20-30 nm) for which the reduction rate (% R) of C. albicans CFU was 45 (p = 0.137), while for the fibers with nAg 100 nm, % R = 7 (p = 0.664).…”

“…In this paper, the composites fibers were produced by the melt-spinning process from Polyamide 12 and four types of the antimicrobial inorganic fillers based on the metal oxides (ZnO, CuO, TiO 2 ) and on nanosilver. In our previous work [22], we examined the effect of the various concentrations of metal oxides (ACRAZ-172) on the PA12, and we found that the highest antimicrobial activity was at 3 wt%. Based on the results, that work aimed to compare the properties of PA12 fibers containing 3 wt% of metal oxides that differed in their composition.…”

Stability Qualification of Resins/Metallic Oxide Composites for Surface Oxidative Protection

“…The addition of metallic oxides in the structure of polymer composites determines the increased material stability in most of the cases [1][2][3][4]. The general overview on the issued papers presenting the improved properties of polymer composite is rather focused on the functional properties, because the majority of assessments principally depict the contributions of fillers to efficient applications [5][6][7][8].…”