<p>Microbial biofilms present a significant global health challenge, as they are associated with severe chronic infections and the emergence of antibiotic resistance. Currently, only a limited number of clinically available drugs effectively target microbial biofilms. This underscores the urgent need for the development of new sustainable therapeutic strategies to address biofilm-associated infections. Developing a sustainable and biodegradable preparation for eradicating microbial biofilms is critically important. In this study, chitosan was extracted from shrimp shell waste and utilized to prepare salicylic acid-loaded chitosan nanoparticles (NPs) using various synthesis methods. The particle size of the prepared nanoparticles ranged from 287.4 to 226.3&#xa0;nm, with zeta potential values between + 36.6 and + 41.3 mV, indicating good stability. The nanoparticles demonstrated safety, with half maximal inhibitory concentration (IC₅₀) values ranging from 1009 to 1346&#xa0;µg/mL. The combination of chitosan and salicylic acid exhibited significant antibiofilm activity against <i>Escherichia coli</i>, <i>Klebsiella pneumoniae</i>, <i>Staphylococcus aureus</i>, and <i>Candida albicans</i>, with particularly high efficacy against <i>Candida albicans</i>, achieving up to 85% biofilm inhibition. While the particle size and antibiofilm activity of the nanoforms showed minimal differences, formulation M4, using sodium alginate, stands out as the most eco-friendly option. This study highlights the potential of bio-sustainable chitosan-based formulations for combating biofilm formation and addressing antimicrobial resistance.</p>