Fuente: PubMed "microbial biotechnology" Microb Biotechnol. 2026 Jul;19(7):e70411. doi: 10.1111/1751-7915.70411.ABSTRACTSubunit vaccines are considered the safest immunization platforms but typically require adjuvants to elicit robust immune responses. Although nanoparticles have emerged as promising adjuvants, biogenic silver nanoparticles (AgNPs) produced by mycosynthesis remain largely unexplored. Herein, nine different AgNPs were mycosynthesized using local strains of Phanerochaete chrysosporium, Penicillium expansum and Punctularia atropurpurascens grown in three different culture media (PDB, MEB, MGYP). Mycosynthesized AgNPs were all shown to be spherical, negatively charged and containing fungal proteins within the biomolecular capping. Additionally, although in vitro biocompatibility assessments showed AgNPs-specific differences in haemolytic and cytotoxic activities, no signs of acute toxicity were observed in mice. The adjuvant potential of AgNPs was further evaluated in ovalbumin-immunized mice, showing that four AgNPs displayed significant immunoenhancement activity with an outstanding IgG2a-polarizaing effect. Adjuvant and IgG subclass polarizing activities were both shown to be dose dependent. Finally, distal effects induced by selected AgNPs were assessed through faecal microbiota analyses. Remarkably, while Firmicutes and Bacteroidota remained the dominant phyla, AgNPs-treated groups showed compositional shifts consistent with mild immunomodulation. Summing up, our results on biocompatibility, adjuvant capacity, strong and dose-dependent IgG2a-polarizing activity, as well as limited impact on gut microbiota, support mycosynthesized AgNPs as versatile next-generation platforms for developing novel vaccine adjuvants.PMID:42432985 | DOI:10.1111/1751-7915.70411