Nanopartículas de ouro e prata em entrega de fármacos e atividade antimicrobiana: conceitos e aplicações

Abstract

Metallic nanoparticles display physicochemical properties that depend on size, morphology, composition and surface chemistry, enabling their use in different biological contexts. This work presents a bibliographic review on noble metal nanoparticles, with a main focus on gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs). AuNPs are discussed mainly as platforms for surface functionalization and drug delivery, owing to their colloidal stability, optical properties and versatile surface modification. AgNPs are addressed with emphasis on antimicrobial activity, considering mechanisms such as bacterial surface adhesion, membrane permeability disruption, reactive oxygen species generation and Ag+ release. Aspects related to synthesis, characterization, drug loading, functionalization and biological translation are also discussed. The review shows that the performance of these systems is not determined only by the metallic core, but by the set of structural and colloidal parameters that define their interaction with cells, proteins, microorganisms and biological media. Therefore, AuNPs and AgNPs are relevant platforms for health-related chemistry, provided that stability, selectivity, toxicity and experimental reproducibility are critically evaluated.