• Scientific advances in aptamer-based biosensors and targeted therapy are systematically reviewed. • Development of aptamer-based biosensors and targeted therapy have vital role in bioassays and clinical treatment. • Challenges and perspectives in these two fields are presented and discussed.

Acute lung injury (ALI) is a severe respiratory disease accompanied by diffuse inflammatory responses induced by various clinical causes. Many fresh medicinal plants have shown better efficacy than their dried forms in preventing and treating diseases like inflammation. As a classical Chinese herb, platycodon grandiflorum (PG) has been demonstrated effective in treating pneumonia, but most of previous studies focused on the efficacy of processed or dried PG formats, while the specific benefits of its fresh form are still underexplored. Exosome-like nanoparticles derived from medicinal plants are expected to point out an important direction for exploring the material basis and mechanism of this fresh herbal medicine. The fresh form of PG could effectively improve ALI induced by lipopolysaccharide (LPS), relieve lung histopathological injury and weight loss, and reduce levels of inflammatory factors in mice, exhibiting better efficacy than dried PG in the treatment of ALI. Further extraction and purification of PG exosome-like nanoparticles (PGLNs) demonstrated that PGLNs had good biocompatibility, with characteristics consistent with general exosome-like nanoparticles. Besides, proteomic analysis indicated that PGLNs were rich in a variety of proteins. Animal experiments showed that PGLNs improved the pathological changes in LPS-induced lung tissues, inhibited the expression of inflammatory factors and promoted the expression of anti-inflammatory factors, and exerted a regulatory effect on the polarization of lung macrophages. Cell experiments further confirmed that PGLNs could be effectively taken up by RAW264.7 cells and repolarize M1 macrophages into M2 type, therefore reducing the secretion of harmful cytokines. Moreover, non-targeted metabolomics analysis reveals that PGLNs reduce inflammation and control macrophage polarization in a manner closely linked to pathways including glycolysis and lipid metabolism, highlighting a potential mechanism by which PGLNs protect the lungs from inflammatory damage like ALI. Fresh PG has better anti-inflammatory and repair effects than its dried form. As one of the most effective active substances in fresh PG, PGLNs may regulate macrophage inflammation and polarization by regulating metabolic pathways including lipid metabolism and glycolysis, so as to reduce inflammation and repair lung injury.

Biofilms, intricate microbial communities that attach to surfaces, especially medical devices, form an exopolysaccharide matrix, which enables bacteria to resist environmental pressures and conventional antimicrobial agents, leading to the emergence of multi-drug resistance. Biofilm-related infections associated with medical devices are a significant public health threat, compromising device performance. Therefore, developing effective methods for supervising and managing biofilm growth is imperative. This in-depth review presents a systematic overview of strategies for monitoring and controlling bacterial biofilms. We first outline the biofilm creation process and its regulatory mechanisms. The discussion then progresses to advancements in biosensors for biofilm detection and diverse treatment strategies. Lastly, this review examines the obstacles and new perspectives associated with this domain to facilitate the advancement of innovative monitoring and control solutions. These advancements are vital in combating the spread of multi drug-resistant bacteria and mitigating public health risks associated with infections from biofilm formation on medical instruments.

Biofilm formation is known to promote drug resistance in methicillin-resistant Staphylococcus aureus (MRSA), which is closely related to persistent infections in hospital settings. In this study, a DNA aptamer specific to penicillin-binding protein 2a (PBP2a) with a dissociation constant (K_d) of 82.97 ± 8.86 nM was obtained after 14 cycles of systematic evolution of ligands by exponential enrichment (SELEX). Next, a bifunctional complex containing the aptamer intercalated by berberine into the double-strand region was prepared and adsorbed onto the surface of graphene oxide (GO) by π-stacking interactions. The GO-loaded aptamer/berberine bifunctional complex showed significantly higher inhibition of MRSA biofilm formation than the control. Furthermore, this study shows that the complex possesses anti-biofilm activity, which can be attributed to the ability of the aptamer to reduce cell-surface attachment by blocking the function of PBP2a and berberine to attenuate the level of the accessory gene regulator (agr) system, which plays an important role in mediating MRSA biofilm formation. Therefore, the simultaneous delivery of berberine and PBP2a-targted aptamer using GO may have potential for the treatment of chronic infections caused by MRSA biofilms. It also provides a new avenue for multitarget treatment of bacterial biofilms.