Molecular hybridization is a well-exploited medicinal chemistry strategy that aims to combine two molecules (or parts of them) in a new, single chemical entity. Recently, it has been recognized as an effective approach to design ligands able to modulate multiple targets of interest. Hybrid compounds can be obtained by linking (presence of a linker) or framework integration (merging or fusing) strategies. Although very promising to combat the multifactorial nature of complex diseases, the development of molecular hybrids faces the critical issues of selecting the right target combination and the achievement of a balanced activity towards them, while maintaining drug-like-properties. In this review, we present recent case histories from our own research group that demonstrate why and how molecular hybridization can be carried out to address the challenges of multitarget drug discovery in two therapeutic areas that are Alzheimer’s and parasitic diseases. Selected examples spanning from linker- to fragment- based hybrids will allow to discuss issues and consequences relevant to drug design.

Cichorium intybus L. or chicory plants are a natural source of health-promoting compounds in the form of supplements such as inulin, as well as other bioactive compounds such as sesquiterpene lactones (SLs). After inulin extraction, chicory roots are considered waste, with most SLs not being harnessed. We developed and optimized a new strategy for SL extraction that can contribute to the conversion of chicory root waste into valuable products to be used in human health-promoting applications. In our work, rich fractions of SLs were recovered from chicory roots using supercritical CO₂. A response surface methodology was used to optimize the process parameters (pressure, temperature, flow rate, and co-solvent percentage) for the extraction performance. The best operating conditions were achieved at 350 bar, 40 °C, and 10% EtOH as a co-solvent in a 15 g/min flow rate for 120 min. The extraction with supercritical CO₂ revealed to be more selective for the SLs than the conventional solid–liquid extraction with ethyl acetate. In our work, 1.68% mass and a 0.09% sesquiterpenes yield extraction were obtained, including the recovery of two sesquiterpene lactones (8-deoxylactucin and 11β,13-dihydro-8-deoxylactucin), which, to the best of our knowledge, are not commercially available. A mixture of the abovementioned compounds were tested at different concentrations for their toxic profile and anti-inflammatory potential towards a human calcineurin/NFAT orthologue pathway in a yeast model, the calcineurin/Crz1 pathway. The SFE extract obtained, rich in SLs, yielded results of inhibition of 61.74 ± 6.87% with 50 µg/mL, and the purified fraction containing 8-deoxylactucin and 11β,13-dihydro-8-deoxylactucin inhibited the activation of the reporter gene up to 53.38 ± 3.9% at 10 µg/mL. The potential activity of the purified fraction was also validated by the ability to inhibit Crz1 nuclear translocation and accumulation. These results reveal a possible exploitable green technology to recover potential anti-inflammatory compounds from chicory roots waste after inulin extraction.

Antimony-doped tin oxide nanoparticles (ATO NPs) have emerged as a promising tool in biomedical applications, namely robust photothermal effects upon near-infrared (NIR) light exposure, enabling controlled thermal dynamics to induce spatial cell death. This study investigated the interplay between ATO NPs and macrophages, understanding cellular uptake and cytokine release. ATO NPs demonstrated biocompatibility with no impact on macrophage viability and cytokine secretion. These findings highlight the potential of ATO NPs for inducing targeted cell death in cancer treatments, leveraging their feasibility, unique NIR properties, and safe interactions with immune cells. ATO NPs offer a transformative platform with significant potential for future biomedical applications by combining photothermal capabilities and biocompatibility.

Purpose: Chemodynamic therapy (CDT) has emerged as a promising cancer treatment strategy leveraging tumor microenvironment conditions to generate reactive oxygen species (ROS) through Fenton-type reactions. This study reports the synthesis, in-depth characterization, and biological evaluation of novel manganese-based zeolitic imidazolate framework (ZIF) nanoparticles, ie, Mn-rods, as a carrier-free potential CDT platform with exceptionally high manganese loading. Methods: Mn-rods were synthesized through coordination of Mn²⁺ ions with 2-methylimidazolate and characterized using transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and inductively coupled plasma optical emission spectroscopy (ICP-OES). Two human non-small cell lung cancer lines (A549 and Calu-3) were used to evaluate nanoparticle internalization and therapeutic response was assessed using cell viability assays, ROS generation measurements, and rescue experiments with pathway-specific inhibitors. Results: The synthesized Mn-rods exhibited a rod-shaped morphology (226 ± 93 nm length x 26.5 ± 9.5 nm width) with an exceptional Mn²⁺ loading of 50 wt.%, surpassing existing manganese-based systems. Both A549 and Calu-3 cells internalized Mn-rods, however, only A549 cells exhibited marked dose-dependent cell viability reduction, highlighting the influence of cellular phenotype on therapeutic response. Mechanistic studies suggest that Mn-rods induce ferroptosis-like cell death in A549 cells through lipid peroxidation and redox imbalance, independent of apoptosis, necroptosis and iron-mediated pathways. Rescue experiments with ferroptosis inhibitors (ferrostatin-1 and liproxstatin-1) confirmed the lipid ROS-driven mechanism, further supported by increased intracellular ROS levels and progressive membrane damage. Conclusion: These findings establish Mn-rods as potent CDT agents whose efficacy is dictated by tumor cell oxidative vulnerability. Understanding such cell-specific responses is critical for optimizing nanoparticle design and tailoring therapeutic strategies in heterogeneous tumor environments. Future studies should extend these investigations across diverse cancer models to refine their translational potential.