Nanocellulose from green algae modulates the in vitro inflammatory response of monocytes/macrophages

The response of monocytes and macrophages to functionalized Cladophora nanocellulose (CC) films was evaluated. Carboxyl-CC and hydroxypropyltrimethylammonium-CC [referred to as anionic-CC (a-CC) and cationic-CC (c-CC), respectively] were synthesized by TEMPO-mediated oxidation and epoxypropyltrimethylammonium chloride condensation of unmodified CC (u-CC). The cell response to u-CC, a-CC and c-CC of untreated and phorbol 12-myristate-13 acetate treated THP-1 cells, i.e. monocytes and macrophages, in the presence and absence of lipopolysaccharide (LPS) was studied. u-CC impairs the viability of THP-1 monocytes and macrophages most probably due to the presence of impurities. In the absence of LPS, the functionalized materials behave as inert materials in terms of the inflammatory response of both monocytes and differentiated macrophages. Under pro-inflammatory stimuli the functionalized CC films suppressed the inflammatory response induced by LPS. The a-CC material with its aggregated, aligned fibre structure caused a more pronounced reduction of TNF-α levels compared to the c-CC film that exhibited non-aggregated, randomly oriented fibres. These results push forward the option of using functionalized CC materials in the biomedical field.