Data for: Fabrication and characterization of antibacterial coatings using an amphoteric condensed tannin,Tanfloc

This dataset presents comprehensive information on the development and characterization of antibacterial polyelectrolyte multilayer (PEM) coatings incorporating tanfloc, a plant-derived condensed tannin polymer with inherent antimicrobial properties. The dataset encompasses experimental data related to the fabrication of PEMs using tanfloc as either a polyanion or a polycation, expanding the versatility of this amphoteric polymer in PEM coatings. Typically, PEMs are formed by combining a polycation and a polyanion with complementary ionic groups. However, the unique amphoteric nature of tanfloc allows for the creation of PEMs utilizing only one of its functional groups, leaving the other functional group available for imparting antibacterial activity.

The dataset includes details on the assembly of tanfloc-containing PEMs employing various counter-polyelectrolytes, including three poly-anionic glycosaminoglycans with varying charge densities, as well as the polycations N,N,N-trimethyl chitosan and polyethylenimine. The layer-by-layer assembly of PEMs is monitored using in situ Fourier-transform surface plasmon resonance (FT-SPR), confirming stable layer-by-layer construction. Surface chemistry is assessed through X-ray photoelectron spectroscopy (XPS).

Furthermore, this dataset provides insights into the biocompatibility of tanfloc-containing PEMs, demonstrating their support for mammalian cells. Most notably, the dataset includes extensive data on the antiadhesive and antibacterial properties of these coatings against common implant-associated pathogens, such as Staphylococcus aureus and Pseudomonas aeruginosa. The antibacterial effects observed are attributed to electrostatic interactions and the polyphenolic nature of tanfloc.

Methods
1H Nuclear Magnetic Resonance (1H NMR): Tanfloc (TAN) was characterized using 1H NMR spectroscopy, recording spectra on a Bruker Neo US 400 NMR spectrometer operating at 400 MHz.

Dynamic Light Scattering (DLS): Solutions of TAN (tanfloc) with varying pH values (5, 6, 7.4, 8.4, and 9.3) were prepared and subjected to dynamic light scattering (DLS) to determine the hydrodynamic diameter and polydispersity index (PDI). This characterization was performed using a Zetasizer Nano ZS instrument from Malvern.

Fourier-Transform Surface Plasmon Resonance (FT-SPR): The layer-by-layer (LBL) assembly of PEMs on gold-coated glass chips was monitored in real-time using Fourier-Transform Surface Plasmon Resonance (FT-SPR). This involved modifying the gold-coated chips, flowing polycation, polyanion, and rinse solutions, and collecting data using an SPR-100 module coupled to a Nicolet 8700 FT-IR spectrometer.

X-ray Photoelectron Spectroscopy (XPS): Composition analysis of the PEMs was performed using X-ray Photoelectron Spectroscopy (XPS). A survey scan was conducted over the energy range of 10 to 1100 eV, with high-resolution spectra obtained for the carbon (C1s), nitrogen (N1s), oxygen (O1s), and sulfur (S2p) envelopes.

LDH Cytotoxicity Assay (ADSC cells): Human adipose-derived stem cells (ADSCs) at passage 6 were cultured in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum and 1.0% penicillin/streptomycin. Sterilized samples were prepared and cells were seeded onto them. After 24 hours, culture media from each well were collected and subjected to the lactate dehydrogenase (LDH) cytotoxicity assay. This involved measuring absorbance at 490 nm and 680 nm using a plate reader (BMG LABTECH FLUOstar Omega). Control samples on polystyrene (PS) were included for comparison.

Bacterial Growth Inhibition Assay: The antibacterial activity of different PEMs was assessed against both Gram-negative Pseudomonas aeruginosa (P. aeruginosa) and Gram-positive Staphylococcus aureus (S. aureus). Bacteria were cultured in nutrient broth media (NBM) and diluted to a concentration of 106 CFU/mL. Subsequently, 500 μL of the bacterial solution was exposed to the surfaces for 6 and 24 hours. After incubation, a 200 μL aliquot of the solution was extracted, and absorbance at 560 nm was measured using a plate reader. Control samples of glass and polystyrene (PS) were also included under identical conditions.

Live-Dead Bacterial Cell Quantification: After incubation for 6 and 24 hours, bacterial adhesion to surfaces was visualized using fluorescence microscopy. The surfaces were stained and fixed before analysis. Live and dead bacterial percentages were determined using ImageJ software (n = 3).