A deeper understanding of unassisted passive transport processes can better delineate basic lipid dynamics in biological membranes. A droplet interface bilayer (DIB) is made by contacting two aqueous droplets covered with a lipid monolayer, and has increasingly been employed as a model artificial biological membrane. In this study, we have investigated the effect of acyl chain structure of amphiphilic monoglycerides on the osmotic permeability of water across DIB membranes composed of these monoglycerides, where the acyl chain length (C14-C24), number of double bonds (1-4), and the position of double bond are varied systematically along the acyl chains. Both permeability values and activation energies have been extracted for water transport across a lipid bilayer formed of a homologous series of lipids, allowing us to make ready comparisons between the different lipids and potentially better elucidate the contributions that molecular motifs make to the permeation process.

Cholesterol is an important component of total lipid in mammalian cellular membranes; hence, the knowledge of its association with lipid bilayer membranes will be essential to understanding membrane structure and function. A droplet interface bilayer (DIB) provides a convenient and reliable platform through which values for permeability coefficient and activation energy of water transport across the membrane can be extracted. In this study, we investigated the effect of acyl chain structure in amphiphilic monoglycerides on the permeability of water across DIB membranes composed of cholesterol and these monoglycerides, where the acyl chain length, number of double bonds, and the position of double bond are varied systematically along the acyl chains. To elucidate the role of cholesterol in these membranes, we investigated its influence on water permeability and associated activation energies at two different cholesterol concentrations. Our systematic studies show dramatic sensitivity and selectivity of specific interaction of cholesterol with the monoglyceride bilayer having structural variations in acyl chain compositions. Our findings allow us to delineate the exquisite interplay between membrane properties and structural components and understand the balanced contribution of each.

Increased attention has been conferred upon interdisciplinary science, technology, engineering, and math (STEM) education to prepare students for deeper understanding to address complex challenges (1-3). Particularly at the undergraduate level, there is recognized value in providing opportunities for students to integrate knowledge across disciplinary boundaries (4-7). In addition to core technical knowledge, it is beneficial to confer behavioral skills that allow students to perform well with others through effective communication, time management, and teamwork (8). Undergraduate research experiences have been considered to be a powerful learning tool, engaging students and stimulating their enthusiasm, thereby improving academic performance and persistence in science and preparing students for advanced degrees and careers in STEM fields (9-17). This report, the culmination of more than a decade's work with undergraduate students, presents practices demonstrating that early exposure to the interdisciplinary field of biophysics can be effectively introduced at a primarily undergraduate institution (PUI) level through a well-structured research plan involving undergraduates with different STEM majors. The management of this group, called ''Project Symphony'' (18), overcame the challenges of sustaining research activities at a PUI via the incorporation of 2 essential elements of success: (a) establishment of a cooperative learning variant whereby students work together to maximize individual learning and each other's learning; and (b) promotion of an integrated understanding via interdisciplinary biophysics projects.