Glover Kj

Bio: Glover Kj is an academic researcher from Lehigh University. The author has contributed to research in topics: Micelle & Lipid bilayer. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

A novel lipid-polymer system with unique properties has potential in drug delivery and biotechnology applications

Abstract: The utility of detergent micelle and bicelle systems has been demonstrated to be a valuable tool for the study of membrane protein interactions and in structural studies. Bicelles are distinguished from micelles in that they contain a lipid bilayer that mimics the plasma membrane of cells making it more native-like than its detergent micelle counter-part. Bicelles are typically comprised of a long-chain phospholipid such as 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and either a short-chain phospholipid, typically 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC), or a bile-salt derivative such as CHAPS or CHAPSO. In solution DMPC and DHPC bicelles assume a discoidal structure comprised of a heterogeneous arrangement where the short-chain lipids gather around the rim of the disk and the long-chain lipids form the flat, bilayer region of the bicelle. Aside from DHPC, CHAPS and CHAPSO few other detergents have reportedly been investigated for their ability to form bicelles with DMPC. In this study, the detergent, C8E5, was used to prepare mixtures with DMPC to determine if it adopts properties similar to DMPC-DHPC bicelles. Mixtures were evaluated using sedimentation equilibrium, 31P-phosphorus NMR, and light scattering and compared to DMPC-DHPC bicelles. Interestingly, mixtures of DMPC and C8E5 assumed a spherical-shaped micellar structure, not the predicted discoidal shape. DMPC-C8E5 mixtures retain interesting properties rendering them particularly advantageous in studies of membrane protein interactions and hold promise as vehicles for drug delivery.

Supported Lipid Bilayer Formation from Phospholipid-Fatty Acid Bicellar Mixtures.

Abstract: Supported lipid bilayers (SLBs) are versatile cell membrane-mimicking biointerfaces for various applications such as biosensors and drug delivery systems, and there is broad interest in developing simple, cost-effective methods to achieve SLB fabrication. One promising approach involves the deposition of quasi-two-dimensional bicelle nanostructures that are composed of long-chain phospholipids and either short-chain phospholipids or detergent molecules. While a variety of long-chain phospholipids have been used to prepare bicelles for SLB fabrication applications, only two short-chain phospholipids, 1,2-dihexanoyl-sn-glycero-3-phosphocholine and 1,2-diheptanoyl-sn-glycero-3-phosphocholine (collectively referred to as DHPC), have been investigated. There remains an outstanding need to identify natural alternatives to DHPC, especially ones that are more affordable, to improve fabrication prospects and application opportunities. Herein, we explored the potential to fabricate SLBs from bicellar mixtures composed of long-chain phospholipids and lauric acid (LA), which is a low-cost, naturally abundant fatty acid that is widely used in soapmaking and various industrial applications. Quartz crystal microbalance-dissipation (QCM-D) experiments were conducted to track bicelle adsorption onto silica surfaces as a function of bicelle composition and lipid concentration, along with time-lapse fluorescence microscopy imaging and fluorescence recovery after photobleaching (FRAP) experiments to further characterize lipid adlayer properties. The results identified optimal conditions where it is possible to efficiently form SLBs from LA-containing bicelles at low lipid concentrations while also unraveling mechanistic insights into the bicelle-mediated SLB formation process and verifying that LA-containing bicelles are biocompatible with human cells for surface coating applications.

Versatile formation of supported lipid bilayers from bicellar mixtures of phospholipids and capric acid

Abstract: Originally developed for the structural biology field, lipid bicelle nanostructures composed of long- and short-chain phospholipid molecules have emerged as a useful interfacial science tool to fabricate two-dimensional supported lipid bilayers (SLBs) on hydrophilic surfaces due to ease of sample preparation, scalability, and versatility. To improve SLB fabrication prospects, there has been recent interest in replacing the synthetic, short-chain phospholipid component of bicellar mixtures with naturally abundant fatty acids and monoglycerides, i.e., lauric acid and monocaprin. Such options have proven successful under specific conditions, however, there is room for devising more versatile fabrication options, especially in terms of overcoming lipid concentration-dependent SLB formation limitations. Herein, we investigated SLB fabrication by using bicellar mixtures consisting of long-chain phospholipid and capric acid, the latter of which has similar headgroup and chain length properties to lauric acid and monocaprin, respectively. Quartz crystal microbalance-dissipation, epifluorescence microscopy, and fluorescence recovery after photobleaching experiments were conducted to characterize lipid concentration-dependent bicelle adsorption onto silicon dioxide surfaces. We identified that uniform-phase SLB formation occurred independently of total lipid concentration when the ratio of long-chain phospholipid to capric acid molecules ("q-ratio") was 0.25 or 2.5, which is superior to past results with lauric acid- and monocaprin-containing bicelles in which cases lipid concentration-dependent behavior was observed. Together, these findings demonstrate that capric acid-containing bicelles are versatile tools for SLB fabrication and highlight how the molecular structure of bicelle components can be rationally finetuned to modulate self-assembly processes at solid-liquid interfaces.