Design and Characterization of Nanostructured Biomaterials via the Self-assembly of Lipids

2013 ◽  
Vol 1498 ◽  
pp. 233-238
Author(s):  
Paul Ludford ◽  
Fikret Aydin ◽  
Meenakshi Dutt

ABSTRACTWe are interested in designing nanostructured biomaterials using nanoscopic building blocks such as functionalized nanotubes and lipid molecules. In our earlier work, we summarized the multiple control parameters which direct the equilibrium morphology of a specific class of nanostructured biomaterials. Individual lipid molecules were composed of a hydrophilic head group and two hydrophobic tails. A bare nanotube encompassed an ABA architecture, with a hydrophobic shaft (B) and two hydrophilic ends (A). We introduced hydrophilic hairs at one end of the tube to enable selective transport through the channel. The dimensions of the nanotube were set to minimize its hydrophobic mismatch with the lipid bilayer. We used a Molecular Dynamics-based mesoscopic simulation technique called Dissipative Particle Dynamics which simultaneously resolves the structure and dynamics of the nanoscopic building blocks and the hybrid aggregate. The amphiphilic lipids and functionalized nanotubes self-assembled into a stable hybrid vesicle or a bicelle in the presence of a hydrophilic solvent. We showed that the morphology of the hybrid structures was directed by factors such as the temperature, the rigidity of the lipid molecules, and the concentration of the nanotubes. Another type of hybrid nanostructured biomaterial could be multi-component lipid bilayers. In this paper, we present approaches to design hybrid nanostructured materials using multiple lipid species with different chemistries and molecular chain stiffness.

2013 ◽  
Vol 1569 ◽  
pp. 51-56 ◽  
Author(s):  
Evan Koufos ◽  
Meenakshi Dutt

ABSTRACTOur objective is to design nanostructured hybrid inorganic-biological materials using the selfassembly of functionalized nanotubes and lipid molecules. In this presentation, we summarize the multiple control parameters which direct the equilibrium morphology of a specific class of nanostructured biomaterials. Individual lipid molecules are composed of a hydrophilic head group and two hydrophobic tails. A bare nanotube encompasses an ABA architecture, with a hydrophobic shaft (B) and two hydrophilic ends (A). We introduce hydrophilic hairs at one end of the tube to enable selective transport through the channel. The dimensions of the nanotube are set to minimize its hydrophobic mismatch with the lipid bilayer. We use a Molecular Dynamicsbased mesoscopic simulation technique called Dissipative Particle Dynamics which simultaneously resolves the structure and dynamics of the nanoscopic building blocks and the hybrid aggregate. The amphiphilic lipids and functionalized nanotubes self-assemble into a stable hybrid vesicle or a bicelle in the presence of a hydrophilic solvent. We demonstrate that the morphology of the hybrid structures is directed by factors such as the temperature, the molecular rigidity of the lipid molecules, and the concentration of the nanotubes. We present material characterization of the equilibrium morphology of the various hybrid nanostructures. A combination of the material characterization and the morphologies of the hybrid aggregates can be used to predict the structure and properties of other hybrid materials.


2012 ◽  
Vol 1464 ◽  
Author(s):  
Meenakshi Dutt ◽  
Olga Kuksenok ◽  
Anna C. Balazs

ABSTRACTVia the Dissipative Particle Dynamics (DPD) approach, we study the self-assembly of hybrid structures comprising lipids and end-functionalized nanotubes. Individual lipids are composed of a hydrophilic head group and two hydrophobic tails. Each bare nanotube encompasses an ABA architecture, with a hydrophobic shaft (B) and two hydrophilic ends (A). To allow for regulated transport through the nanotube, we also introduce hydrophilic hairs at one end of the tube. The amphiphilic lipids are composed of a hydrophilic head group (A) and two hydrophobic tails (B). We select the dimensions of the nanotube architecture to minimize its hydrophobic mismatch with the lipid bilayer. We find the amphiphilic lipids and functionalized nanotubes to self-assemble into a stable hybrid vesicle or a bicelle in the presence of a hydrophilic solvent. We demonstrate that the morphology of the self-assembled functionalized nanotube-lipid hybrid structures is controlled by the rigidity of the lipid molecules and concentration of the nanotubes.


2017 ◽  
Vol 4 (4) ◽  
pp. 161092 ◽  
Author(s):  
G. Indelicato ◽  
P. Burkhard ◽  
R. Twarock

We introduce here a mathematical procedure for the structural classification of a specific class of self-assembling protein nanoparticles (SAPNs) that are used as a platform for repetitive antigen display systems. These SAPNs have distinctive geometries as a consequence of the fact that their peptide building blocks are formed from two linked coiled coils that are designed to assemble into trimeric and pentameric clusters. This allows a mathematical description of particle architectures in terms of bipartite (3,5)-regular graphs. Exploiting the relation with fullerene graphs, we provide a complete atlas of SAPN morphologies. The classification enables a detailed understanding of the spectrum of possible particle geometries that can arise in the self-assembly process. Moreover, it provides a toolkit for a systematic exploitation of SAPNs in bioengineering in the context of vaccine design, predicting the density of B-cell epitopes on the SAPN surface, which is critical for a strong humoral immune response.


Author(s):  
Yizhaq Engelberg ◽  
Meytal Landau

Protein fibrils that perform biological activities present attractive biomaterials. Here we demonstrate, by crystal structures, the self-assembly of the antibacterial human LL-37 active core (residues 17-29) into a stable structure of densely packed helices. The surface of the fibril encompasses alternating hydrophobic and positively charged zigzagged belts, which likely underlie interactions with and subsequent disruption of negatively charged lipid bilayers, such as bacterial membranes. LL-3717-29 correspondingly formed wide, ribbon-like, thermostable fibrils in solution, which co-localized with bacterial cells, and structure-guided mutagenesis analyses supported the role of self-assembly in antibacterial activity. LL-3717-29 resembled, in sequence and in the ability to form amphipathic helical fibrils, the bacterial cytotoxic PSMα3 peptide that assembles into cross-α amyloid fibrils. This suggests helical, self-assembling, basic building blocks across kingdoms of life and point to potential structural mimicry mechanisms. The findings offer a scaffold for functional and durable nanostructures for a wide range of medical and technological applications.


Author(s):  
Raihan Tayeb ◽  
Yuwen Zhang

Abstract A mesoscopic simulation method combining multiphase Volume of Fluid (VOF) method and Dissipative Particle Dynamics (DPD) is employed to investigate and control self-assembly of charged polymeric nanoparticles in microdroplet solution deposited on plane substrate during solvent evaporation. A droplet evaporation model is first developed and validated. A coupling scheme between the CFD and the DPD simulation for particles is then presented. The DPD simulation includes the DLVO forces between the particles, their interaction with the substrate surface, Stokes drag, Brownian, and capillary forces. Numerical results show qualitative agreement with available experimental results. The proposed simulation method is expected to provide valuable tools for controlling and optimizing self-assembly of nanoparticles.


2005 ◽  
Author(s):  
Ki Young Kim ◽  
Ki-Taek Byun ◽  
Ho-Young Kwak

With a simple model of surfactant which consists of hydrophilic head group and hydrophobic tail groups connected by harmonic springs, structural change of the association structures of surfactant in an aqueous solution was studied using the dissipative particle dynamics (DPD) simulation. The effect of the hydrophilic interaction between the head and water molecules and the hydrophobic interaction between the tail and water molecules and the head and tail on the structural change of the association structures was studied. Simulations show that proper value of these interaction parameters could yield desirable change of the association structure depending on the concentration of the surfactant. For example, a hexagonal structure appears when the volume fraction of surfactant of SDS (sodium dodecyl sulfate) becomes 25% in aqueous solution, which is in good agreement with observation.


2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.


2018 ◽  
Author(s):  
Erik Leonhardt ◽  
Jeff M. Van Raden ◽  
David Miller ◽  
Lev N. Zakharov ◽  
Benjamin Aleman ◽  
...  

Extended carbon nanostructures, such as carbon nanotubes (CNTs), exhibit remarkable properties but are difficult to synthesize uniformly. Herein, we present a new class of carbon nanomaterials constructed via the bottom-up self-assembly of cylindrical, atomically-precise small molecules. Guided by supramolecular design principles and circle packing theory, we have designed and synthesized a fluorinated nanohoop that, in the solid-state, self-assembles into nanotube-like arrays with channel diameters of precisely 1.63 nm. A mild solution-casting technique is then used to construct vertical “forests” of these arrays on a highly-ordered pyrolytic graphite (HOPG) surface through epitaxial growth. Furthermore, we show that a basic property of nanohoops, fluorescence, is readily transferred to the bulk phase, implying that the properties of these materials can be directly altered via precise functionalization of their nanohoop building blocks. The strategy presented is expected to have broader applications in the development of new graphitic nanomaterials with π-rich cavities reminiscent of CNTs.


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