The coronavirus disease (COVID-19) pandemic poses serious global health concerns with the continued emergence of new variants. The periodic outbreak of novel emerging and re-emerging infectious pathogens has elevated concerns and challenges for the future. To develop mitigation strategies against infectious diseases, nano-based approaches are being increasingly applied in diagnostic systems, prophylactic vaccines, and therapeutics. This review presents the properties of various nanoplatforms and discusses their role in the development of sensors, vectors, delivery agents, intrinsic immunostimulants, and viral inhibitors. Advanced nanomedical applications for infectious diseases have been highlighted. Moreover, physicochemical properties that confer physiological advantages and contribute to the control and inhibition of infectious diseases have been discussed. Safety concerns limit the commercial production and clinical use of these technologies in humans; however, overcoming these limitations may enable the use of nanomaterials to resolve current infection control issues via application of nanomaterials as a platform for the diagnosis, prevention, and treatment of viral diseases.

Messenger RNA (mRNA) therapies have emerged as potent and personalized alternatives to conventional DNA-based therapies. However, their therapeutic potential is frequently constrained by their molecular instability, susceptibility to degradation, and inefficient cellular delivery. This study presents the nanoparticle “ChargeSome” as a novel solution. ChargeSomes are designed to protect mRNAs from degradation by ribonucleases (RNases) and enable cell uptake, allowing mRNAs to reach the cytoplasm for protein expression via endosome escape. We evaluated the physicochemical properties of ChargeSomes using ¹H nuclear magnetic resonance, Fourier-transform infrared, and dynamic light scattering. ChargeSomes formulated with a 9:1 ratio of mPEG-b-PLL to mPEG-b-PLL-SA demonstrated superior cell uptake and mRNA delivery efficiency. These ChargeSomes demonstrated minimal cytotoxicity in various in vitro structures, suggesting their potential safety for therapeutic applications. Inherent pH sensitivity enables precise mRNA release in acidic environments and structurally protects the encapsulated mRNA from external threats. Their design led to endosome rupture and efficient mRNA release into the cytoplasm by the proton sponge effect in acidic endosome environments. In conclusion, ChargeSomes have the potential to serve as effective secure mRNA delivery systems. Their combination of stability, protection, and delivery efficiency makes them promising tools for the advancement of mRNA-based therapeutics and vaccines.

A fluorescence-based detection platform was developed for brain-derived neurotrophic factor (BDNF), a key biomarker of Alzheimer’s disease (AD). This platform utilizes localized surface plasmon resonance effects resulting from the interactions between silica-coated gold nanoparticles (Au@SiO₂) and enzymatically synthesized quantum dots (QDs). The gold nanoparticles were silica coated via the hydrolysis of tetraethyl orthosilicate, which allowed for precise control over the distance between the nanoparticles and QDs and refined the dynamics of fluorescence quenching and enhancement. Antibody conjugation was performed via sequential amination and carboxylation, followed by EDC/NHS coupling. BDNF was detected across a range of concentrations, from 1 ng/mL to 1 ng/mL, using an alkaline phosphatase (ALP)-conjugated polyclonal antibody targeting a secondary epitope of BDNF. The enzymatic hydrolysis of p-nitrophenyl phosphate by immobilized ALP led to the formation of cadmium sulfide QDs, with the fluorescence intensity correlating directly with the BDNF concentration. This platform offers a refined and precise method for detecting BDNF and is a reliable tool for the early diagnosis of AD.

Oral vaccines must withstand gastric acid and mucus, reach microfold cells, and trigger durable mucosal IgA, but most carriers cannot simultaneously provide enteric protection, on-demand intestinal activation, and predictable biodegradation. We present magnesium-propelled polymersome (PSome) nanomotors (ActiPSomes) that conserve chemical fuel in the stomach via an enteric overcoat and activate in the intestine to enhance transport and antigen encounter. After coating, the hydrodynamic diameter increased from 141.33 ± 3.62 nm to 188.63 ± 2.03 nm, confirming formation of a protective layer. Nanoparticle-tracking analysis showed negligible directional motion under gastric conditions (pH 2.0) but pronounced propulsion at intestinal pH (pH 8.0); the size mobility relationship followed MSD theory with R² ≈ 0.96. In vitro, ActiPSomes increased macrophage uptake of Nile-red-labeled antigen ∼2.8-fold versus particles without magnesium and maintained a ∼2.1-fold advantage after sequential exposure to simulated gastric and intestinal environments. In vivo, oral dosing elicited significantly higher PEDV-specific IgA titers in feces and intestines at days 7 and 14 compared with controls (p < 0.05-0.001), with no adverse clinical signs or weight loss over 14 days. Mechanistically, intestinal pH dissolves the enteric layer to expose intravesicular Mg, generating hydrogen that drives active diffusion while PLA hydrolysis supports intestinal biodegradation. These data establish a generalizable nanoplatform for enteric-protected, fuel-efficient oral vaccination against mucosal pathogens. In this study, we developed magnesium-propelled PSome nanomotors, termed ActiPSomes, that integrate enteric protection, pH-triggered propulsion, and intestinal biodegradation to enhance oral antigen delivery and mucosal immunity.