Measles virus (MeV) is a paramyxovirus that infects humans, principally children. Despite the existence of an effective and safe vaccine, the number of cases of measles has increased due to lack of vaccination coverage. The World Health Organization (WHO) reports that the number of cases worldwide multiplied fourfold between January and March 2019, to 112,000. Today, there is no treatment available for MeV. In recent years, it has been demonstrated that natural extracts (herbal or algal) with antiviral activity can also work as reducing agents that, in combination with nanotechnology, offer an innovative option to counteract viral infections. Here, we synthetized and evaluated the antiviral activity of gold nanoparticles using garlic extract (Allium sativa) as a reducing agent (AuNPs-As). These nanoparticles actively inhibited MeV replication in Vero cells at a 50% effective concentration (EC₅₀) of 8.829 µg/mL, and the selectivity index (SI) obtained was 16.05. AuNPs-As likely inhibit viral infection by blocking viral particles directly, showing a potent virucidal effect. Gold nanoparticles may be useful as a promising strategy for treating and controlling the infection of MeV and other related enveloped viruses.

The deproteinization of chitosan is a necessary purification process for materials with biomedical purposes; however, chitosan sourcing and purification methods can modify its molecular weight, deacetylation degree, and residual proteins. These factors affect the reactive groups that affect the immunomodulatory activities of cells, particularly macrophages and monocytes; considering this activity is key when developing successful and functional biomaterials. Here, two brands of chitosan were purified and used to synthesize nanoparticles to evaluate their immunomodulatory effect on monocyte and macrophage differentiation. Chitosan FT-IR showed bands related to its purification process, with increased OH group intensity. Nanoparticles (CtsNps) synthesized with purified chitosan were of a smaller size compared to those using unpurified chitosan due to the alkaline purification process’s shortening of the polymeric chain. At low concentrations (50 $\mathsf{\mu }$g/mL), CtsNps showed a lower expression of CD80 and CD14, corroborating the differentiation effect of chitosan. Inducible nitric oxide synthase (iNOS) is related to a pro-inflammatory response and M1 macrophage polarization was detected in monocytes treated with purified and unpurified nanoparticles. Sigma-purified chitosan nanoparticles (CtsNps SigmaP), at 300 $\mathsf{\mu }$g/mL, showed arginase production related to an anti-inflammatory response and M2 macrophage polarization. The chitosan purification process induces a shift in the polarization of macrophages to an anti-inflammatory M2 profile. This effect is concentration-dependent and should be further studied in each use case to favor the suitable biological response.

Background: Gold nanoparticles enhance immunity, promotes antigen uptake by antigen-presenting cells (APCs), and boost the response against tumor antigens; therefore, they are a promising delivery vehicle. Tumor lysates have shown favorable responses as inductors of anti-cancer immunity, but the effectiveness of these treatments could be improved. Hybrid nanosystems gold nanoparticles with biomolecules have been show promising alternative on uptake, activation and response on immune system. Objectives: This study’s objective was to develop a method of synthesizing gold nanoparticles employing a triple-negative breast cancer (4T1) cell lysate (AuLtNps) as a reducing agent to increase immunogenicity against breast cancer cells. Methods: Nanoparticle formation, size, and $\zeta$ potential were confirmed by surface plasmon resonance, dynamic light scattering, and transmission electron microscopy. Protein concentration was quantified using a Pierce BCA assay. The cytotoxic effects of treatments on murine macrophages were assessed, along with nanoparticle and tumor lysate uptake via epifluorescence microscopy. Using a murine model, cytokine secretion profiles were determined, and the efficacy in inhibiting the implantation of a 4T1 model was evaluated. Results/Conclusions: AuLtNps exhibited higher protein content than tumor lysate alone, leading to increased uptake and phagocytosis in murine macrophages, as confirmed by epifluorescence microscopy. Cytokine secretion analysis showed a proinflammatory response, with increased CD8+ and CD22+ lymphocytes and upregulation of APC markers (CD14, CD80, CD86, and MHC II+). Splenocytes demonstrated specific lysis of up to 40% against 4T1 tumor cells. In a murine model, AuLtNPs effectively inhibited tumor implantation, achieving an improved 90-days survival rate, highlighting their potential as an immunotherapy for triple-negative breast cancer.

Electrospun fibers can reproduce the architecture of natural tissues while enabling the controlled release of bioactive compounds; therefore, this study evaluated whether the PCL/zein ratio and flavonoid identity govern the properties of fibers loaded with naringin (NI) or naringenin (NE). PCL and PCL/zein (90:10 and 80:20) fibers containing 5 wt.% NI or NE were produced by electrospinning and characterized by computational analysis, morphology, thermal and mechanical testing, water uptake, degradation, flavonoid release, antioxidant and antibacterial assays, and MG-63 viability and ALP activity. All formulations yielded homogeneous fibers. Increasing the zein content reduced fiber diameter to 0.53 ± 0.20 µm and increased water uptake to ~460%, while fibers containing 20% zein and NE exhibited the highest Young’s modulus (15.22 ± 1.42 MPa). Zein modulated NI and NE release in a flavonoid-dependent manner, with increasing zein promoting greater retention of NE over 72 h. PZ20NE showed the highest antioxidant activity (49.6%) and near-complete inhibition of S. aureus (~99.8%), and approximately 85% inhibition of E. coli. All formulations maintained high MG-63 cell viability, while fibers containing 20% zein and NI produced the strongest ALP response. Overall, scaffold performance depended on polymer ratio and flavonoid structure, supporting their potential as multifunctional materials for future bone tissue repair applications.

Reliable assessment of nanoparticle–cell interactions is essential for the development of nanomedicine, drug delivery systems, and nanobiomaterials. Current analytical approaches, including electron microscopy, flow cytometry, fluorescence-based assays, and inductively coupled plasma mass spectrometry (ICP-MS), often require specialized instrumentation, expensive reagents, or destructive sample preparation, limiting their accessibility in many laboratories. Here, we describe a simple, rapid, and reproducible label-free UV–Visible spectroscopy method for estimating nanoparticle–cell association by quantifying the fraction of plasmonic metallic nanoparticles remaining in the extracellular medium after incubation with adherent cells. The method monitors changes in surface plasmon resonance (SPR) intensity before and after cellular exposure and can be implemented using either a NanoDrop spectrophotometer or a conventional UV–Vis microplate reader operating between 300 and 800 nm. The methodology was validated using four chemically distinct gold nanoparticle formulations and four adherent cell lines representing different biological models, demonstrating reproducible discrimination of nanoparticle–cell association across multiple experimental conditions. Although the method provides an indirect measure of nanoparticle association rather than intracellular localization, it offers a rapid, cost-effective, and broadly accessible platform for the preliminary screening of metallic nanoparticle–cell interactions in laboratories without access to advanced imaging or elemental analysis instrumentation.