Sara T. Roldan Velasquez

Amphiphilic polymer conetworks were mechanically reinforced with a combination of peptide blocks and cellulose nanocrystals, resulting in transparent, water-swellable and hexane-swellable gels with excellent mechanical properties.

Amphiphilic polymer conetworks (APCNs) have been explored for applications, including soft contact lenses, biomaterials, and membranes. They combine several important properties of hydrogels and elastomers, including elasticity, transparency, and capability to swell in water. Moreover, they also swell in organic solvents. However, their mechanical properties could be improved. We developed a two-level, bio-inspired, hierarchical reinforcement of APCNs using peptide-containing triblock copolymers and cellulose nanocrystals (CNCs). Bio-inspired peptide-polymer hybrids combine the structural hierarchy often found in natural materials with synthetic macromolecules, e.g. having soft and hard segments like in multiblock copolymers, to strengthen the mechanical properties. On the other hand, CNCs provide an additional way to dissipate mechanical energy in polymeric materials and, therefore, for reinforcement. The key to achieving homogeneous incorporation of CNCs into the APCNs is the combination of hydrophobic CNCs (HCNCs) with peptide-modified APCNs, exploiting the hydrogen bonding present in the peptides to disperse the HCNCs. The effect of HCNCs on the ability of APCNs to swell in water and organic solvents and on the thermal and mechanical properties was characterized. Additionally, the nanostructure of the materials was analyzed via small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS). The CNC-containing APCNs exhibited similar swellability independent of the CNC concentration, and all the samples were highly transparent. The ideal CNC concentration, in terms of maximal stress, strain, toughness, and reinforcement was found to be between 6 and 15 wt%, and an increase of Young´s modulus by up to 500% and of toughness of up to 200% was achieved. The hierarchical reinforcement also greatly strengthened the APCNs when swollen in water and n-hexane. Thus, CNCs and peptide segments can be used to reinforce APCNs and to tailor their properties.

To increase biodiversity in tomato cultivation, two herbal aromatic plants, thyme (Thymus vulgaris) and basil (Ocimum basilicum L.), were introduced as companion plants. Their role was to improve crop plant growth and stress resistance. Moreover, the effect of the soil application of Trichoderma microbial preparations on tomato growth parameters and yield, in combination with companion plants, was studied. Ligno-cellulose multi-layer microcapsules with Trichoderma atroviride TRS14 spores (MIC14) and the commercial preparation Trianum G (TG) were used as microbial preparations. This experiment was carried out in a certified organic field. Tomato plants were intercropped with thyme or basil in the arrangement of two tomato rows alternating with one herbal row. In all intercropping arrangements and in the control (tomato plants grown without herbs), subplots were sectioned. The soil in the subplots was amended with the MIC14 and TG preparations used at a concentration of 10⁴ spores g⁻¹ of the soil and planted with tomato transplants. No control measures were applied during tomato growing, and the plants were naturally infected with late blight. Tomato plant growth parameters and yield were assessed, and late blight severity was monitored. The degree of soil colonization by Trichoderma fungi and the effect of these applications on soil microbial activity and biodiversity (dehydrogenases activity, EcoPlates AWCD, and Shannon index) were evaluated. The results clearly showed a significant influence of thyme and basil on tomato growth and yield in organic production. The cultivation of thyme adjacent to tomatoes had a beneficial effect on the development of the root system and the number of flowers and fruits on the crop plants. Basil, on the other hand, clearly decreased tomato yield and adversely affected the effect of Trichoderma applications by reducing root system development. Moreover, basil as a companion plant increased late blight symptoms. Both Trichoderma strains colonized soil, but they had no significant effect on the microbial activity or metabolic potential measured on the EcoPlates with the use of the BIOLOG system. However, a decrease in dehydrogenases activity was noted. In organic cultivation, the Trichoderma preparations used had no significant effect on tomato yield, opposite to its increase in integrated tomato production.

Microcapsules with an aqueous core can be conveniently prepared by water‐in‐oil‐in‐water double emulsion microfluidics. However, conventional shell materials are based on hydrophobic polymers or colloidal particles. Thus, these microcapsules feature a hydrophobic shell impermeable to water‐soluble compounds. Capsules with semipermeable hydrogel shells have been demonstrated but may exhibit poor mechanical properties. Here, amphiphilic polymer conetworks (APCNs) based on poly(2‐hydroxyethyl acrylate)‐linked by‐polydimethylsiloxane (PHEA‐l‐PDMS) are introduced as a new class of wall materials in double emulsion microcapsules. These APCNs are mechanically robust silicone hydrogels that are swellable and permeable to water and are soft and elastic when dry or swollen. Therefore, the microcapsules can be dried and rehydrated multiple times or shrunken in sodium chloride salt solutions without getting damaged. Moreover, the APCNs are permeable for hydrophilic organic compounds and impermeable for macromolecules. Thus, they can be loaded with macromolecules or nanoparticles during microfluidic formation and with organic molecules after capsule synthesis. The microcapsules serve as microreactors for catalytically active platinum nanoparticles that decompose hydrogen peroxide. Finally, the surface of the APCN microcapsules can be selectively functionalized with a cholesterol‐based linker. Concluding, APCN microcapsules could find applications for the controlled delivery of drugs, as microreactors for synthesis, or as scaffolds for synthetic cells.

Agricultural fungicide pollution poses a significant environmental challenge and causes adverse effects on human health. Therefore, strategies to limit fungicide usage are of paramount importance. Trichoderma fungi, due to their antagonistic activity against various pathogenic fungi, have shown potential as a sustainable alternative to chemical fungicides. However, bio‐control agents like Trichoderma are vulnerable to physical stimuli and show diminished efficacy during prolonged storage. To address these challenges, a mild and scalable encapsulation method for Trichoderma spores is introduced, employing a layer‐by‐layer (LbL) approach using biobased lignin derivatives. It is demonstrated that the LbL encapsulation technique significantly improved spore stability relative to naked spores, even under adverse conditions including extreme temperatures and prolonged exposure to Ultraviolet (UV) irradiation. Notably, encapsulated Trichoderma spores showed enhanced efficacy in cultivating tomato plants compared to naked spores. Additionally, the findings revealed that the in planta efficacy of encapsulated spores is dependent on the specific Trichoderma strain used. This study suggests that Trichoderma spores encapsulated with lignin through the LbL approach, are a promising and sustainable alternative to chemical fungicides with potential for commercialization.

Agricultural fungicide pollution poses a significant environmental challenge and carries adverse consequences for human health. Therefore, strategies to limit fungicide usage have gained paramount importance. Trichoderma fungi, owing to their antagonistic activity against various pathogenic fungi, have emerged as prospective candidates for enhancing both the effectiveness and sustainability of plant protection. Nevertheless, the utilization of bio-control agents like Trichoderma has unveiled new challenges, notably their vulnerability to physical stimuli and diminished efficacy during prolonged storage. To overcome these drawbacks, we present a mild and scalable encapsulation method for Trichoderma spores, employing a layer-by-layer (LbL) encapsulation approach using biobased lignin derivates. Our investigations demonstrate that the LbL-encapsulation technique imparts remarkable improvements in spore stability, even under adverse conditions such as variable temperature and prolonged exposure to UV irradiation compared to unencapsulated spores. Notably, encapsulated Trichoderma spores exhibit increased efficiency in the cultivation of tomato plants when compared to their unencapsulated counterparts. Additionally, our findings reveal that the in planta efficacy of encapsulated spores is contingent upon the specific Trichoderma strain employed. The results outlined herein suggest that Trichoderma spores, encapsulated within lignin through the LbL approach, exhibit potential as promising and sustainable alternative to chemical fungicides and potential commercialization.

Microcapsules with aqueous core can be conveniently prepared by water-in-oil-in-water double emulsion microfluidics. However, conventional shell materials are either based on polymers or monomers that are soluble in the oil phase, or based on hydrophobic colloidal particles. As a result, microcapsules derived from double emulsions usually feature a hydrophobic shell that is not semipermeable for water-soluble compounds. While capsules with semipermeable hydrogel shells have been demonstrated, these may exhibit poor mechanical properties and lack the robustness required in many applications. In this study, amphiphilic polymer conetworks (APCNs) based on poly(2-hydroxyethyl acrylate)-linked by-polydimethylsiloxane (PHEA-l-PDMS) are introduced as a new class of wall materials in double emulsion microcapsules. These APCNs are mechanically robust silicone hydrogels that are swellable and permeable to water, and are soft and elastic in the dry and swollen states. Thus, the microcapsules can be dried and rehydrated multiple times or shrunken in sodium chloride salt solutions without getting damaged. Moreover, the APCNs are semipermeable for hydrophilic organic compounds, while being impermeable for macromolecules and colloids. Thus, they can be loaded with macromolecules or nanoparticles during microfluidic formation, and with organic molecules after capsule synthesis. Uptake into and release from the capsules were studied with the model compounds fluorescein and fluorescently labelled dextran. Moreover, the microcapsules served as microreactors for catalytically active platinum nanoparticles that decomposed hydrogen peroxide. Finally, the surface of APCN microcapsules can be selectively functionalized with a cholesterol-based linker that non-covalently binds to the hydrophobic domains of the APCN. Thus, APCN microcapsules represent versatile and broadly applicable capsules that could find application for the controlled delivery of drugs, as microreactors for synthesis, or even as scaffolds for synthetic cells.

Amphiphilic polymer conetworks (APCNs) are polymer networks composed of hydrophilic and hydrophobic chain segments. Their applications range from soft contact lenses to membranes and biomaterials. APCNs based on polydimethylsiloxane (PDMS) and poly(2‐hydroxyethyl acrylate) are flexible and elastic in the dry and swollen state. However, they are not good at resisting deformation under load, i.e., their toughness is low. A bio‐inspired approach to reinforce APCNs is presented based on the incorporation of poly(β‐benzyl‐L‐aspartate) (PBLA) blocks between cross‐linking points and PDMS chain segments. The mechanical properties of the resulting peptide‐reinforced APCNs can be tailored by the secondary structure of the peptide chains (β‐sheets or a mixture of α‐helices and β‐sheets). Compared to non‐reinforced APCNs, the peptide‐reinforced networks have higher extensibility (53 vs. up to 341%), strength (0.71 ± 0.16 vs. 22.28 ± 2.81 MPa), and toughness (0.10 ± 0.04 vs. up to 4.85 ± 1.32 MJ m⁻³), as measured in their dry state. The PBLA peptides reversibly toughen and reinforce the APCNs, while other key material properties of APCNs are retained, such as optical transparency and swellability in water and organic solvents. This paves the way for applications of APCNs that benefit from significantly increased mechanical properties.

The Lindau Nobel Laureate Meeting 2025 (LINO25) brought together more than 30 laureates and 600 young scientists in the field of chemistry from over 100 countries. One of the most remarkable contributions came from Latin America, with 24 young researchers from seven countries showcasing the high level, commitment, and diversity of science in the region. This special article documents the experience and contributions of this delegation, highlights their active role in scientific debates, their attainment of Nobel Alumni status, and their key recommendations for future generations. In addition, it provides a practical guide on the nomination process, logistical preparation, and strategies to maximize the experience during the event. Finally, it underlines the importance of increasing Latin America's visibility and strengthening its representation, including countries that have historically been underrepresented, in high-impact international scientific spaces such as Lindau.