Microfluidic Synthesis of Lipid-Polymer Hybrid Nanoparticles for Targeted Drug Delivery

MRS Advances ◽  
2016 ◽  
Vol 1 (29) ◽  
pp. 2155-2160
Author(s):  
Eri A. Takami ◽  
Folarin Erogbogbo

ABSTRACTLipid-polymer hybrid nanoparticles (LPHN) have great potential as drug delivery devices for treatment of serious medical issues such as cardiovascular disease, tuberculosis, and cancer. Nanoprecipitation is a commonly used method to synthesize LPHN in a low cost manner. However, this multi-step process proves to be difficult in consistently producing uniformly sized nanoparticles. Here we developed a microfluidic device that utilizes a three-channel pathway and mixer channel to synthesize uniformly sized LPHN in a controlled manner. Dynamic light scattering results of the microfluidic synthesized nanoparticles show decrease in diameter size from 140 nm to 40 nm as the Reynolds number of the channel inflow increases. Transmission electron microscopy confirms the size and morphology of the nanoparticles. Three dimensional structure of the LPHN were observed using atomic force microscopy. The production of higher quality nanoparticles using our microfluidics device can expedite the research and development process of drug delivering lipid polymer nanoparticles.

2020 ◽  
Author(s):  
Betül Gürünlü ◽  
Çiğdem Taşdelen-Yücedağ ◽  
Mahmut Bayramoğlu

Liquid Phase Exfoliation (LPE) method has been gaining increasing interest by academic and industrial researchers due to its simplicity, low-cost, and scalability. High intensity ultrasound energy was exploited to transform graphite to graphene in the solvents of dimethyl sulfoxide (DMSO), N,N-dimethyl formamide (DMF), and perchloric acid (PA) without any surfactants or ionic liquids. The crystal structure, number of layers, particle size, and morphology of the synthesized graphene samples were characterized by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), Ultraviolet visible (UV–vis) spectroscopy, Dynamic Light Scattering (DLS), and Transmission Electron Microscopy (TEM). XRD and AFM analyses indicated that G-DMSO and G-DMF have few layers and G-PA has multilayers. The layer numbers of G-DMSO, G-DMF, and G-PA were determined as 9, 10, and 21, respectively. By DLS analysis, the particle sizes of graphene samples were estimated in a few micrometers. TEM analyses showed that G-DMSO and G-DMF possess sheet-like fewer layers and also, G-PA has wrinkled and unordered multilayers.


1999 ◽  
Vol 5 (S2) ◽  
pp. 380-381
Author(s):  
S. J. Eppell ◽  
W. Tong ◽  
J. L. Katz ◽  
L. Kuhn-Spearing ◽  
M. J. Glimcher

Study of the microscopic structure of bone dates back to the earliest use of the optical microscope. Understanding the complexities of the structure of this material has roughly paralleled advances in microscopic technique. Relatively recently a new powerful microscopic technique, atomic force microscopy (AFM), has been invented. So it should not be surprising to expect a new step in our understanding of bone. There have been several recent publications applying AFM to bone and its constituents. None of these studies have examined the shape of naturally occurring mineralites in bone. The issue we addsgss in this work is the elucidation of the three dimensional structure of the apatite mineralites in bone. Chiefly, two methods have been used previously to ascertain this structure: transmission electron microscopy (TEM) and X-ray diffraction (XRD,). The major difficulty with TEM is that it is a projection technique. Each image only yields information about geometry in a single plane. Landis et al. showed how to circumvent this problem using tomographic TEM. AFM provides a corroborative and perhaps more gentle method of directly measuring the structure of very small bone mineralites. It is possible that the interaction energy of the electron beam with very small mineralites is sufficient to vaporize them. The problem with XRD is that the line broadening used can have contributions from sources not directly related to mineralite size. In particular, if a single mineralite contains more than one crystalline domain, then the line broadening yields a measure of the domain size, not the overall mineralite size.


Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1037
Author(s):  
Betül Gürünlü ◽  
Çiğdem Taşdelen-Yücedağ ◽  
Mahmut Bayramoğlu

The liquid-phase exfoliation (LPE) method has been gaining increasing interest by academic and industrial researchers due to its simplicity, low cost, and scalability. High-intensity ultrasound energy was exploited to transform graphite to graphene in the solvents of dimethyl sulfoxide (DMSO), N,N-dimethyl formamide (DMF), and perchloric acid (PA) without adding any surfactants or ionic liquids. The crystal structure, number of layers, particle size, and morphology of the synthesized graphene samples were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), ultraviolet visible (UV–vis) spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM). XRD and AFM analyses indicated that G-DMSO and G-DMF have few layers while G-PA has multilayers. The layer numbers of G-DMSO, G-DMF, and G-PA were determined as 9, 10, and 21, respectively. By DLS analysis, the particle sizes, polydispersity index (PDI), and zeta potential of graphene samples were estimated in a few micrometers. TEM analyses showed that G-DMSO and G-DMF possess sheet-like fewer layers and also, G-PA has wrinkled and unordered multilayers.


Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.


2002 ◽  
Vol 718 ◽  
Author(s):  
N.D. Zakharov ◽  
P. Werner

AbstractThe structure and composition of UMo8O26 synthesized by solid state reaction method have been investigated by High Resolution Transmission Electron Microscopy (HRTEM), Selected Area Electron Diffraction, and EDX microanalysis. The ordering of U vacancies results in considerable enlargement of unit cell parameters: an=6.44 nm, bn=1.45 nm, cn=1.6 nm. It is build up of four layers piled up in c direction. Each following layer is shifted relative to previous one by vector bn/4. Eight hexagonal tunnels in each layer are filled by U atoms, while the eight others are vacant (V). Interaction between U cations and vacancies is driving force for ordering. The variation of stoichiometry can be a reason for appearance of incommensurate modulations in these crystals. It seems plausible that this structure might also exhibit superconductivity at low temperatures.


2017 ◽  
Vol 23 (3) ◽  
pp. 661-667 ◽  
Author(s):  
Yue Li ◽  
Di Zhang ◽  
Ilker Capoglu ◽  
Karl A. Hujsak ◽  
Dhwanil Damania ◽  
...  

AbstractEssentially all biological processes are highly dependent on the nanoscale architecture of the cellular components where these processes take place. Statistical measures, such as the autocorrelation function (ACF) of the three-dimensional (3D) mass–density distribution, are widely used to characterize cellular nanostructure. However, conventional methods of reconstruction of the deterministic 3D mass–density distribution, from which these statistical measures can be calculated, have been inadequate for thick biological structures, such as whole cells, due to the conflict between the need for nanoscale resolution and its inverse relationship with thickness after conventional tomographic reconstruction. To tackle the problem, we have developed a robust method to calculate the ACF of the 3D mass–density distribution without tomography. Assuming the biological mass distribution is isotropic, our method allows for accurate statistical characterization of the 3D mass–density distribution by ACF with two data sets: a single projection image by scanning transmission electron microscopy and a thickness map by atomic force microscopy. Here we present validation of the ACF reconstruction algorithm, as well as its application to calculate the statistics of the 3D distribution of mass–density in a region containing the nucleus of an entire mammalian cell. This method may provide important insights into architectural changes that accompany cellular processes.


Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 242 ◽  
Author(s):  
Monica Terracciano ◽  
Luca De Stefano ◽  
Ilaria Rea

Diatom microalgae are the most outstanding natural source of porous silica. The diatom cell is enclosed in a three-dimensional (3-D) ordered nanopatterned silica cell wall, called frustule. The unique properties of the diatom frustule, including high specific surface area, thermal stability, biocompatibility, and tailorable surface chemistry, make diatoms really promising for biomedical applications. Moreover, they are easy to cultivate in an artificial environment and there is a large availability of diatom frustules as fossil material (diatomite) in several areas of the world. For all these reasons, diatoms are an intriguing alternative to synthetic materials for the development of low-cost drug delivery systems. This review article focuses on the possible use of diatom-derived silica as drug carrier systems. The functionalization strategies of diatom micro/nanoparticles for improving their biophysical properties, such as cellular internalization and drug loading/release kinetics, are described. In addition, the realization of hybrid diatom-based devices with advanced properties for theranostics and targeted or augmented drug delivery applications is also discussed.


Agronomy ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 56 ◽  
Author(s):  
Eric Bertoft

Starch is a major food supply for humanity. It is produced in seeds, rhizomes, roots and tubers in the form of semi-crystalline granules with unique properties for each plant. Though the size and morphology of the granules is specific for each plant species, their internal structures have remarkably similar architecture, consisting of growth rings, blocklets, and crystalline and amorphous lamellae. The basic components of starch granules are two polyglucans, namely amylose and amylopectin. The molecular structure of amylose is comparatively simple as it consists of glucose residues connected through α-(1,4)-linkages to long chains with a few α-(1,6)-branches. Amylopectin, which is the major component, has the same basic structure, but it has considerably shorter chains and a lot of α-(1,6)-branches. This results in a very complex, three-dimensional structure, the nature of which remains uncertain. Several models of the amylopectin structure have been suggested through the years, and in this review two models are described, namely the “cluster model” and the “building block backbone model”. The structure of the starch granules is discussed in light of both models.


2017 ◽  
Vol 2 (4) ◽  
pp. 269-280 ◽  
Author(s):  
Vivek Dave ◽  
Renu Bala Yadav ◽  
Kriti Kushwaha ◽  
Sachdev Yadav ◽  
Swapnil Sharma ◽  
...  

2005 ◽  
Vol 38 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Leonore Wiehl ◽  
Jens Oster ◽  
Michael Huth

Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundummsurface was determined.


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