Multifunctional bioactivity of sulfated spirulina polysaccharides-biofunctionalized silver nanoparticles in tuberculosis: In vitro anti-inflammatory and immunomodulatory effects on lymphocytes from patients with diverse mycobacterial tuberculosis strains

Abstract

Silver nanoparticles (AgNPs) show promise as complementary agents to standard anti-tuberculosis therapies, especially for multidrug-resistant TB (MDR-TB). However, their therapeutic effectiveness and safety must be evaluated to ensure suitability for clinical trials. This study assessed anti-inflammatory and immunomodulatory in vitro effects of the Spirulina-derived polysaccharides (SPSp)-biofunctionalized AgNPs’ compared with SPSp on lymphocytes collected from TB patient infected with diverse mycobacterial strains. For in vitro analysis using cell models peripheral blood lymphocytes were collected from 78 pulmonary TB patients: 45 infected with multidrug-resistant strains (including 22 cases infected before the onset of the treatment and 23 cases which acquired drug-resistance during the anti-TB treatment) and 33 with drug-susceptible strains. Immunomodulatory activity was measured via phytohemagglutinin-induced blast transformation test and immune modulation index. Pro- and anti-inflammatory activity was assessed through IFN-γ, IL-4 and IL-10 concentration in the supernatant. Results: statistical analysis confirmed that Spirulina-derived polysaccharides decreased IFN-γ release, whereas biofunctionalized AgNPs enhanced its production. Both active biological agents increased anti-inflammatory cytokines (IL-4 and IL-10), with a more pronounced effect observed following administration of Spirulina-derived polysaccharides. Among tested groups, lymphocytes from patients with drug-susceptible TB exhibited the strongest response, followed by those with primary drug-resistance, while from patients with acquired MDR-TB showed the weakest reaction. These findings suggested that both Spirulina-derived polysaccharides and AgNPs biofunctionalized with these polysaccharides can be used as immunostimulatory therapies, due to their dual pro- and anti-inflammatory effects and the potential to restore immune balance.