Anti-Inflammatory Activity of Biomaterials Intended for Periodontal Disease Treatment ^†

Periodontal disease is associated with chronic tissue inflammation, which besides bacterial plaque can lead to enzymatic degradation of the extracellular matrix components from the periodontal ligament, cementum, and alveolar bone [1]. Several studies have reported an increased level of pro-inflammatory cytokines, but also apoptosis events that resulted in cell detachment from the extracellular matrix [2]. The aim of this study was to evaluate the anti-inflammatory activity of natural polymeric biomaterials enriched with silver nanoparticles, in view of their use for periodontitis treatment.

Two types of biomaterials were prepared, one as a polymeric composite based on components of the extracellular matrix, collagen, chondroitin sulfate, and fibronectin [3] and one as a hybrid material by adding silver nanoparticles. Ultrastructural observations were performed by SEM with a Hitachi SU 1510 equipment (Tokyo, Japan), operated at 15 kV, in nitrogen atmosphere. To determine the anti-inflammatory activity, THP-1 cells (ATCC) inflamed with bacterial lipopolysaccharide were cultivated in the presence of biomaterials for 24 h and then the culture medium was analyzed for interleukin-1β (IL-1β) and tumor necrosis factor alfa (TNF-α) pro-inflammatory cytokines level using sandwich ELISA kits (R&D Systems Inc., Minneapolis, MN, USA). Statistical analysis was performed using Student t-test.

SEM images showed the presence of silver nanoparticles mainly on collagen fibrils and their homogeneously distribution within the polymeric matrix. Unlike the polymeric composite, the hybrid material presented a significant inhibition (60–70%; p < 0.05) of pro-inflammatory cytokines secretion (Figure 1). This effect was probably due to silver nanoparticles interference in distinct signaling pathways preventing cell proliferation, as discussed in previous studies [4].

The presence of silver nanoparticles within the hybrid material represented a clear advantage by increasing its anti-inflammatory activity and demonstrating its possible application in periodontitis treatment.