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Segars BG, Makhoul-Mansour M, Beyrouthy J, Freeman EC. Measuring the Transmembrane Registration of Lipid Domains in Droplet Interface Bilayers through Tensiometry. Langmuir 2024. [PMID: 38753461 DOI: 10.1021/acs.langmuir.4c00958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
Diverse collections of lipids self-assemble into domains within biological membranes, and these domains are typically organized in both the transverse and lateral directions of the membrane. The ability of the membrane to link these domains across the membrane's interior grants cells control over features on the external cellular surface. Numerous hypothesized factors drive the cross-membrane (or transverse) coupling of lipid domains. In this work we seek to isolate these transverse lipid-lipid influences in a simple model system using droplet interface bilayers (DIBs) to better understand the associated mechanics. DIBs enable symmetric and asymmetric combinations of domain-forming lipid mixtures within a model bilayer, and the evolving energetics of the membrane may be tracked using drop-shape analysis. We find that symmetric distributions of domain-forming lipids produce long-lasting, gradual shifts in the DIB membrane energetics that are not observed in asymmetric distributions of the lipids where the domain-forming lipids are only within one leaflet. The approach selected for this work provides experimental measurement of the mismatch penalty associated with antiregistered lipid domains as well as measurements of the influence of rafts on DIB behaviors with suggestions for their future use as a model platform.
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Affiliation(s)
- Braydon G Segars
- School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, 110 Riverbend Road, Athens, Georgia 30605, United States
| | - Michelle Makhoul-Mansour
- School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, 110 Riverbend Road, Athens, Georgia 30605, United States
- Mechanical, Agricultural, Biomedical, and Environmental Engineering Department, Tickle College of Engineering, University of Tennessee Knoxville, 1512 Middle Dr., Knoxville, Tennessee 37916, United States
| | - Joyce Beyrouthy
- School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, 110 Riverbend Road, Athens, Georgia 30605, United States
| | - Eric C Freeman
- School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, 110 Riverbend Road, Athens, Georgia 30605, United States
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Zhu Y, Xu Y, Yan J, Fang Y, Dong N, Shan A. "AMP plus": Immunostimulant-Inspired Design Based on Chemotactic Motif -( PhHA hPH) n. ACS Appl Mater Interfaces 2023; 15:43563-43579. [PMID: 37691475 DOI: 10.1021/acsami.3c09353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Ability to stimulate antimicrobial immunity has proven to be a useful therapeutic strategy in treating infections, especially in the face of increasing antibiotic resistance. Natural antimicrobial peptides (AMPs) exhibiting immunomodulatory functions normally encompass complex activities, which make it difficult to optimize their therapeutic benefits. Here, a chemotactic motif was harnessed as a template to design a series of AMPs with immunostimulatory activities plus bacteria-killing activities ("AMP plus"). An amphipathic peptide ((PhHAhPH)n) was employed to improve the antimicrobial impact and expand the therapeutic potential of the chemotactic motif that lacked obvious bacteria-killing properties. A total of 18 peptides were designed and evaluated for their structure-activity relationships. Among the designed, KWH2 (1) potently killed bacteria and exhibited a narrow antimicrobial spectrum against Gram-negative bacteria and (2) activated macrophages (i.e., inducing Ca2+ influx, cell migration, and reactive oxygen species production) as a macrophage chemoattractant. Membrane permeabilization is the major antimicrobial mechanism of KWH2. Furthermore, the mouse subcutaneous abscess model supported the dual immunomodulatory and antimicrobial potential of KWH2 in vivo. The above results confirmed the efficiency of KWH2 in treating bacterial infection and provided a viable approach to develop immunomodulatory antimicrobial materials with desired properties.
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Affiliation(s)
- Yunhui Zhu
- Laboratory of Molecular Nutrition and Immunity, Nutrition and Immunity, College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang 150038, China
| | - Yinghan Xu
- Laboratory of Molecular Nutrition and Immunity, Nutrition and Immunity, College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang 150038, China
| | - Jianming Yan
- Laboratory of Molecular Nutrition and Immunity, Nutrition and Immunity, College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang 150038, China
| | - Yuxin Fang
- Laboratory of Molecular Nutrition and Immunity, Nutrition and Immunity, College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang 150038, China
| | - Na Dong
- Laboratory of Molecular Nutrition and Immunity, Nutrition and Immunity, College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang 150038, China
| | - Anshan Shan
- Laboratory of Molecular Nutrition and Immunity, Nutrition and Immunity, College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang 150038, China
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El-Beyrouthy J, Makhoul-Mansour M, Gulle J, Freeman E. Morphogenesis-inspired two-dimensional electrowetting in droplet networks. Bioinspir Biomim 2023; 18. [PMID: 37074106 DOI: 10.1088/1748-3190/acc779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/24/2023] [Indexed: 05/03/2023]
Abstract
Living tissues dynamically reshape their internal cellular structures through carefully regulated cell-to-cell interactions during morphogenesis. These cellular rearrangement events, such as cell sorting and mutual tissue spreading, have been explained using the differential adhesion hypothesis, which describes the sorting of cells through their adhesive interactions with their neighbors. In this manuscript we explore a simplified form of differential adhesion within a bioinspired lipid-stabilized emulsion approximating cellular tissues. The artificial cellular tissues are created as a collection of aqueous droplets adhered together in a network of lipid membranes. Since this abstraction of the tissue does not retain the ability to locally vary the adhesion of the interfaces through biological mechanisms, instead we employ electrowetting with offsets generated by spatial variations in lipid compositions to capture a simple form of bioelectric control over the tissue characteristics. This is accomplished by first conducting experiments on electrowetting in droplet networks, next creating a model for describing electrowetting in collections of adhered droplets, then validating the model against the experimental measurements. This work demonstrates how the distribution of voltage within a droplet network may be tuned through lipid composition then used to shape directional contraction of the adhered structure using two-dimensional electrowetting events. Predictions from this model were used to explore the governing mechanics for complex electrowetting events in networks, including directional contraction and the formation of new interfaces.
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Affiliation(s)
- Joyce El-Beyrouthy
- School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, Athens, GA, United States of America
| | - Michelle Makhoul-Mansour
- School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, Athens, GA, United States of America
- College of Engineering, University of Tennessee Knoxville, Knoxville, TN, United States of America
| | - Jesse Gulle
- School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, Athens, GA, United States of America
| | - Eric Freeman
- School of Environmental, Civil, Agricultural, and Mechanical Engineering, University of Georgia, Athens, GA, United States of America
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