Salt-induced diffusiophoresis is the movement of a charged nanoparticle in water, driven by an imposed directional gradient of salt concentration. This transport phenomenon has become an important tool for manipulating the motion of charged nanoparticles within porous materials and microfluidic systems. Micelles are valuable nanoparticles with the ability to host small guest molecules in aqueous media. Therefore, understanding micelle diffusiophoresis is also crucial for transport of small molecules. This poster reports experimental diffusiophoresis coefficients for the cationic micelle of hexadecylpyridinium chloride (CPC) in water the presence of NaCl and KCl. Thermodynamic parameters characterizing micelle-salt interactions were also experimentally determined. We find that micelle-salt interaction is the essentially the same for both salts. In contrast, we find that diffusiophoresis of CPC micelles occurs from high to low salt concentration in the NaCl case, while it occurs in the opposite direction in the KCl case. A model describing micelle-salt interactions and micelle diffusiophoresis based on theory of electric double layer is reported. This work offers new insights into diffusiophoresis of charged nanoparticles with potential applications for enhanced-oil recovery from porous rocks, micellar ultrafiltration for the purification of industrial water, and diffusion-based mixing inside microfluidics.

This research aims to develop and characterize synthetic riboswitches for creatinine and trimethylamine N-oxide (TMAO), metabolic biomarkers for kidney and cardiovascular dysfunctions. Riboswitches are structured RNA elements located in the 5’-untranslated regions (UTRs) of bacterial mRNAs that regulate downstream gene expression through ligand-induced conformational changes with high affinity and selectivity. To select for the synthetic riboswitches specific to creatinine, the glycine riboswitch library was subjected to a dual genetic selection. In the positive selection, the riboswitches that bind to creatinine or any endogenous molecules will produce the CAT-UPP fusion protein, allowing the host cells to survive in the presence of chloramphenicol. The negative selection is carried out in media containing 5-fluorouracil (5-FU) in the absence of creatinine. Any riboswitches activated by endogenous ligands will die in the presence of 5-FU. The surviving cells should contain the riboswitches that are activated only by creatinine. After several repeated selection steps, including increased concentrations of chloramphenicol and 5-FU, no glycine riboswitch variants were identified to show chloramphenicol resistance in the presence of creatinine. We will continue the project with different riboswitch libraries. We identified a synthetic riboswitch to TMAO, a riboswitch that was derived from the genetic selection of the theophylline riboswitch library that clearly shows chloramphenicol resistance only in the presence of TMAO. We will further test this TMAO riboswitch by colorimetric or fluorescence assays using β-galactosidase and green fluorescence protein, respectively, in the presence of varying concentrations of TMAO.

Sustainable synthetic approaches to drug delivery carriers such as porous silicon are becoming increasingly important for biomedical applications such as drug delivery, where extreme electronic-grade purity is not required, even though silicon remains a critical material in electronics and energy technologies. This work develops a green, self-propagating high-temperature synthesis (SHS) approach to produce high-surface-area porous silicon using plant-derived silicon dioxide (SiO₂) as the precursor, magnesium (Mg) as the reductant, and sodium chloride (NaCl) as a thermal moderator. The exothermic magnesiothermic reaction is initiated using a controlled electrical input of less than (or equal to) 9V, enabling silicon formation while significantly reducing external energy requirements compared to conventional high-temperature silicon production methods.

In practice, Mg and SiO₂ reactants are exposed to a finite voltage for approximately 10–15 minutes to allow the SHS reaction to propagate. After synthesis, the crude product is purified by dissolving reaction byproducts in concentrated hydrochloric acid, leaving behind porous silicon. X-ray powder diffraction (XRD) is used to evaluate crystallinity and phase composition. While XRD analysis confirms the formation of silicon, persistent crystalline silica peaks indicate incomplete reduction and phase coexistence that currently limits effective separation. Ongoing work focuses on optimizing reaction conditions and refining reaction kinetics to improve phase selectivity and identify optimal synthesis parameters. Despite these challenges, the low-energy synthesis strategy and use of accessible raw materials highlight the potential of SHS-derived porous silicon as a scalable and sustainable platform for future drug delivery applications, particularly in resource-limited settings.

Oxidative stress plays a significant role in the progression of Alzheimer’s disease, making cellular antioxidant pathways attractive therapeutic targets. The Keap1–Nrf2 signaling pathway regulates the cellular response to oxidative stress, and inhibition of the Keap1 protein can activate Nrf2, promoting neuroprotective antioxidant responses. In this study, a series of quinoline-modified macrocyclic compounds were designed and synthesized to evaluate their potential as Keap1 inhibitors.
Computational and experimental approaches were employed to investigate the interaction of these compounds with the Keap1 protein. In-silico studies were conducted to analyze the binding affinity of the synthesized compounds using molecular docking, molecular dynamics simulations, and machine learning–based prediction of IC₅₀ values. These analyses provided insight into the stability of the ligand–protein complexes and the structural features that influence binding interactions.
The computational results indicate that compounds containing polar substitutions on the upper synthon exhibit stronger binding affinity and form more stable complexes with the Keap1 protein. Additionally, modification of the macrocyclic scaffold with quinoline substitution on the side nitrogen was found to enhance interactions with the protein binding pocket, suggesting a favorable structural motif for Keap1 inhibition.
Together, these findings provide insight into structure–activity relationships for this class of compounds and highlight promising molecular features for the development of Keap1 inhibitors as potential therapeutic leads for Alzheimer’s disease.

Chemotherapy relies on two therapeutic paradigms. The classic approach, most often used, employs small molecules to specifically target enzyme active sites, as represented by the new generation of kinase inhibitors. A secondary approach relies on interfering with protein-protein interactions thus requiring the use of larger compounds. While this latter strategy is garnering the attention of the pharmaceutical community, the rules for the design of these larger molecules, which are often cyclic, are not understood. The compact shape of small molecules leads to predictable behaviors including oral availability and cell uptake. For larger molecules that adopt multiple shapes, understanding the factors that control their shape and dynamic motion provides opportunities to predict similar behaviors that are critical for rational drug design. Here, the synthesis and characterization of a library of large, cyclic molecules (macrocycles) is described. The macrocycles of interest result from the dimerization of monomers. A total of 50 monomers containing different drug-like groups were synthesized. Reaction of a single monomer yields a homodimer, while combination of two different monomers leads to a 1:1:2 mixture of homodimers and a heterodimer. These combinations ultimately lead to a library of 1,275 different compounds. Liquid chromatography-mass spectrometry confirms that >99.9% of the reactions were successful. To investigate the biological activity of these compounds, we have provided this library to high throughput drug-screening facilities at Vanderbilt University and Scripps Florida. Of the several compounds created, macrocycles containing hydroxylamine groups are of special interest for two reasons. First, these molecules are similar to Hydrea, a widely-used, FDA-approved cancer drug. Second, unlike most macrocycles, both the shape and dynamics of these molecules are well understood so critical parameters such as oral availability and membrane transit can be predicted.