2.7.2. Ciprofloxacin Release

The samples loaded with ciprofloxacin were deposited in vials containing 3 mL of phosphate buffer solution at pH 7.4 and 37 ◦C with constant stirring (130 rpm). The cumulative release was monitored by taking measurements at 0.25, 0.5, 1, 2, 4, 6, 8, 24, 30, and 48 h at 266 nm using a UV–Vis spectrophotometer. The calibration curve is shown in Supplementary Materials, Figure S2. The release profiles were analyzed by the software DDSolver, and the detailed results are presented in Supplementary Materials.

### *2.8. Protein Adsorption Test*

Approximately 80 mg of a sample were placed in PBS buffer solution at 37 ◦C for 2 h, then the sample was extracted and incubated in bovine serum albumin (BSA) protein solution at a 30 mg/mL concentration in PBS at 37 ◦C for 2 h. After this time, the materials were washed three times with PBS, and the adhered protein was extracted for later quantification.

For the extraction, 600 μL of 1% wt. SDS solution were added to the sample, previously incubated in BSA, and proceeded to be shaken at 130 rpm for 20 min and sonicated for 10 min, and finally vortexed for 30 s; this process was repeated 3 times. Finally, the protein concentration was quantified using the bicinchoninic acid method: 1 mL of the extraction solution was placed in a glass vial, 2 mL of the working solution (Table S1) was added, the mixture was gently shaken and heated at 60 ◦C for 30 min. After this time, the sample was cooled to room temperature, and the absorbance was measured using UV–Vis spectroscopy at 556 nm. Quantification was performed using a calibration curve (Supplementary Materials, Figure S3).

### *2.9. Cell Viability Assay*

Cell viability was studied by observing the growth of BALB/3T3 murine embryonic fibroblasts (ATCC CCL-163, Manassas, VA, USA) in the presence of the modified materials. The assays were performed in 96-well plates seeded with 4 × <sup>10</sup><sup>4</sup> cells/mL, using Dulbecco's modified Eagle's medium (DMEM) with FBS (fetal bovine serum, 10% *v*/*v*), penicillin-streptomycin (1% *w*/*v*) and gentamicin (10 μg/mL), for 24 h, under standard culture conditions (a humidified atmosphere of 5% CO2, at 37 ◦C). Samples of approximately six μg were added to the cell culture and incubated for 24 h. After this, the samples and the medium were removed, and the MIT kit was used to quantify them, measuring the absorbance at 620 nm (Multiskan FC, Thermo Scientific). Cell viability was obtained by comparing cell growth in the presence of samples with that obtained by cultures without them. The assay was performed in triplicate.

### *2.10. Bacterial Inhibition Test*

A solution of *Escherichia coli* (ATCC25922) of 0.5 MF (1.5 × <sup>10</sup><sup>8</sup> cfu/mL) was prepared in peptone water (pH: 7.2) and 2 mL of the solution was placed in a test tube, which had been previously sterilized (121 ◦C, 15 min and pressure of 1.6 kg/cm2). The material to be analyzed was placed in the medium and incubated at 37 ◦C for 24 h. The material was removed from the culture medium, and the optical density was measured at 600 nm by spectroscopy to quantify the inhibition of growth by comparing the difference between it and a solution whose bacterial growth was not affected by any external material [29]; the experiments were carried out in triplicate.
