Innovative Polymeric Sponges Loaded with Andiroba Oil and Cu(II) Complex: Synthesis, Characterization, Controlled Release, and Antimicrobial Activity

Innovative polymeric sponges composed of andiroba oil (Carapa guianensis Aubl.) and 1,10-phenanthroline/Copper(II) crystalline complex, dispersed in sodium alginate and cellulose matrix were developed and their structural, vibrational, thermal, swelling, and antimicrobial properties characterized. The sponges were prepared by mixing the two polysaccharides with a fixed amount of andiroba oil following the addition of Cu(II) complex at different concentrations. The characterization of the samples by scanning electron microscopy and X-ray diffraction showed amorphous structures with several micropores. All sponges displayed water absorption capacity, with swelling increasing progressively over 120 min. Biodegradation assays were performed in phosphate buffer to evaluate sponges’ degradation profile. Fourier transformed infrared spectra (FT-IR) revealed their main functional groups, together with bands assigned to interaction between Cu²⁺ ions and organic compounds. Differential scanning calorimetry analysis indicated compromised thermal stability attributed to sponges’ dehydration. The sponges containing Cu(II) complex demonstrated controlled release of Cu²⁺ ions, with ions being released within the first 30 min. The antimicrobial effects were evaluated against strains of Gram-positive and Gram-negative bacteria, confirming the bactericidal activity of the developed sponges. These findings suggest that sponges composed of Cu²⁺ ions and andiroba oil have potential pharmaceutical applications to be used as a biomaterial with antimicrobial properties.