Nanocomposites in Drug Delivery and Imaging Applications

2021 ◽  
pp. 1539-1554
Author(s):  
Dimple Sethi Chopra
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Thermal Analysis ◽  
Cancer Treatment ◽  
Polymer Matrix ◽  
Cell Imaging ◽  
Xrd Pattern ◽  
Chemical Functionalization ◽  
Disease Biomarkers ◽  
The Matrix

Nanocomposites are a class of materials in which one or more phases with nanoscale dimensions are embedded in a metal, ceramic, or polymer matrix. The properties of nanocomposites depend on matrix, loading, degree of dispersion, size, shape, and orientation of the nanoscale phase and interaction between the matrix and the nanoscale phase. Nanocomposites are generally prepared using direct melt intercalation. The formation of nanocomposite is ascertained by XRD pattern, FTIR spectra, electron microscopy, and thermal analysis like DSC and TGA. Nanocomposites have properties of nanoparticles, multifunctional capabilities, chemical functionalization, huge interphase zone. Novel nanomaterials offer a new chemotherapeutic route for cancer treatment by combining cell imaging and hyperthermia in a synergistic way. In spite of toxicity and safety concerns, multifunctional nanocomposite still interest the researchers because of emergence of versatile properties, better understanding of disease biomarkers, and quest for ways to improve biocompatibility.

Nanocomposites in Drug Delivery and Imaging Applications

2018 ◽  
pp. 415-430
Author(s):  
Dimple Sethi Chopra
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Thermal Analysis ◽  
Cancer Treatment ◽  
Polymer Matrix ◽  
Cell Imaging ◽  
Xrd Pattern ◽  
Chemical Functionalization ◽  
Disease Biomarkers ◽  
The Matrix

Nanocomposites are a class of materials in which one or more phases with nanoscale dimensions are embedded in a metal, ceramic, or polymer matrix. The properties of nanocomposites depend on matrix, loading, degree of dispersion, size, shape, and orientation of the nanoscale phase and interaction between the matrix and the nanoscale phase. Nanocomposites are generally prepared using direct melt intercalation. The formation of nanocomposite is ascertained by XRD pattern, FTIR spectra, electron microscopy, and thermal analysis like DSC and TGA. Nanocomposites have properties of nanoparticles, multifunctional capabilities, chemical functionalization, huge interphase zone. Novel nanomaterials offer a new chemotherapeutic route for cancer treatment by combining cell imaging and hyperthermia in a synergistic way. In spite of toxicity and safety concerns, multifunctional nanocomposite still interest the researchers because of emergence of versatile properties, better understanding of disease biomarkers, and quest for ways to improve biocompatibility.

Influence of Microwave on the Structure and Properties of Nanomodified Fluoroplastic

2021 ◽  
Vol 887 ◽  
pp. 10-16
Author(s):  
D.O. Zavrazhin ◽  
A.A. Chuprikova ◽  
Ju.S. Povetkina
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Polymer Matrix ◽  
Carbon Nanomaterials ◽  
Microwave Treatment ◽  
Heating Time ◽  
Structure And Properties ◽  
The Matrix ◽  
Scanning Electron ◽  
Polar Polymer

Polymers modified with carbon nanomaterials exhibit enhanced electrical conductivity. The modifier, which is qualitatively distributed in the polymer matrix, actively absorbs microwave waves even with an extremely small introduced volume (up to 1.5 mass parts). Photographs obtained by scanning electron microscopy indicate a uniform distribution of carbon nanotubes in the matrix of fluoroplastic 4. The microwave treatment of the obtained composites showed a significant increase in the temperature of the samples with a heating time of up to 100 sec. even with minimal amounts of modifier added. Strength characteristics for a uniaxial plant of modified materials after microwave increase by 40-50%. The obtained modified materials based on a non-polar polymer matrix have enhanced characteristics of absorption of microwave radiation.

Routes to Control the Chemical Potential and to Modulate the Reactivity of Nanodiamond Surfaces

2015 ◽  
Vol 1734 ◽  
Author(s):  
Giacomo Reina ◽  
Silvia Orlanducci ◽  
Stefano Gay ◽  
Angelo Gismondi ◽  
Teresa Lavecchia ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Cell Imaging ◽  
Chemical Potential ◽  
Detonation Nanodiamond ◽  
Open Problems ◽  
Chemical Functionalization ◽  
Wet Chemistry ◽  
Antioxidant Molecule ◽  
Modification Of The Surface

ABSTRACTThe use of detonation nanodiamond (DND) for drug delivery and cell-imaging is grounded on its chemical functionalization, and the key task to be addressed is the capability to simplify the process steps, to reduce the process times and to maximize the drug/ligand uptake. The idea underlying the present research is to modulate the loading capability of DND by controlled modification of the surface organic groups. To this aim the DND samples are treated either by wet chemistry, using medium-strong reducing agents, or by tunable H-plasmas produced in a custom-designed MW-RF reactor. The affinity of the treated DND surfaces for drugs has been probed by conjugating the ciproten (5,7- dimethoxycoumarin), a natural antioxidant molecule, and by testing in vitro the feasibility to use coumarin vehicled by nanodiamond (C@DND) as chemioterapeutic drug. The methodologies developed to modify the DND surfaces are offering practical solutions to the still open problems related to DND-based systems for drug delivery applications.

Electron microscopy and diffraction studies of polyimides

1983 ◽  
Vol 41 ◽  
pp. 28-29
Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Structural Features ◽  
Inert Atmosphere ◽  
Polyimide Films ◽  
Resolution Electron ◽  
The Matrix ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

Using crystallographic symmetry in diffraction and contrast analysis

1989 ◽  
Vol 47 ◽  
pp. 504-505
Author(s):  
U. Dahmen ◽  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
High Symmetry ◽  
Two Phase ◽  
Tem Analysis ◽  
Crystallographic Symmetry ◽  
The Matrix ◽  
Contrast Analysis ◽  
Practical Tool ◽  
Convergent Beam ◽  
Beam Diffraction

Despite the increased use of convergent beam diffraction, symmetry concepts in their more general form are not commonly applied as a practical tool in electron microscopy. Crystal symmetry provides an abundance of information that can be used to facilitate and improve the TEM analysis of crystalline solids. This paper draws attention to some aspects of symmetry that can be put to practical use in the analysis of structures and morphologies of two-phase materials.It has been shown that the symmetry of the matrix that relates different variants of a precipitate can be used to determine the axis of needle- or lath-shaped precipitates or the habit plane of plate-shaped precipitates. By tilting to a special high symmetry orientation of the matrix and by measuring angles between symmetry-related variants of the precipitate it is possible to find their habit from a single micrograph.

Optical Properties of Photodynamic Therapy Drugs in Different Environments: The Paradigmatic Case of Temoporfin

2020 ◽  
Author(s):  
busenur Aslanoglu ◽  
Ilya Yakavets ◽  
Vladimir Zorin ◽  
Henri-Pierre Lassalle ◽  
Francesca Ingrosso ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Optical Properties ◽  
Photodynamic Therapy ◽  
Minimally Invasive ◽  
Visible Light ◽  
Cancer Treatment ◽  
Singlet Oxygen ◽  
Tumor Cells ◽  
Molecular Oxygen ◽  
Computational Tools

Computational tools have been used to study the photophysical and photochemical features of photosensitizers in photodynamic therapy (PDT) –a minimally invasive, less aggressive alternative for cancer treatment. PDT is mainly based by the activation of molecular oxygen through the action of a photoexcited sensitizer (photosensitizer). Temoporfin, widely known as mTHPC, is a second-generation photosensitizer, which produces the cytotoxic singlet oxygen when irradiated with visible light and hence destroys tumor cells. However, the bioavailability of the mostly hydrophobic photosensitizer, and hence its incorporation into the cells, is fundamental to achieve the desired effect on malignant tissues by PDT. In this study, we focus on the optical properties of the temoporfin chromophore in different environments –in <i>vacuo</i>, in solution, encapsulated in drug delivery agents, namely cyclodextrin, and interacting with a lipid bilayer.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

Novel Interpenetrating Polymer Matrix Network Microparticles for Intestinal Drug Delivery

2014 ◽  
Vol 11 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Jagadeeswara Reddy ◽  
B. Nagashubha ◽  
Mahesh Reddy ◽  
Afrasim Moin ◽  
H.G. Shivakumar
Keyword(s):  
Drug Delivery ◽  
Polymer Matrix

Matrix Metalloproteinases (MMPs) in Targeted Drug Delivery: Synthesis of a Potent and Highly Selective Inhibitor against Matrix Metalloproteinase- 7

2020 ◽  
Vol 20 (27) ◽  
pp. 2459-2471
Author(s):  
Ling-Li Wang ◽  
Bing Zhang ◽  
Ming-Hua Zheng ◽  
Yu-Zhong Xie ◽  
Chang-Jiang Wang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tumor Microenvironment ◽  
Matrix Metalloproteinases ◽  
Cancer Treatment ◽  
Targeted Drug Delivery ◽  
Selective Inhibitor ◽  
Migration And Invasion ◽  
Side Chains ◽  
Mesenchymal Transition ◽  
Targeted Drug

Background: Matrix metalloproteinases (MMPs) are a family of zinc endopeptidases that play a key role in both physiological and pathological tissue degradation. MMPs have reportedly shown great potentials in the degradation of the Extracellular Matrix (ECM), have shown great potentials in targeting bioactive and imaging agents in cancer treatment. MMPs could provoke Epithelial to Mesenchymal Transition (EMT) of cancer cells and manipulate their signaling, adhesion, migration and invasion to promote cancer cell aggressiveness. Therefore, targeting and particularly inhibiting MMPs within the tumor microenvironment is an effective strategy for cancer treatment. Based on this idea, different MMP inhibitors (MMPIs) have been developed to manipulate the tumor microenvironment towards conditions appropriate for the actions of antitumor agents. Studies are ongoing to improve the selectivity and specificity of MMPIs. Structural optimization has facilitated the discovery of selective inhibitors of the MMPs. However, so far no selective inhibitor for MMP-7 has been proposed. Aims: This study aims to comprehensively review the potentials and advances in applications of MMPs particularly MMP-7 in targeted cancer treatment approaches with the main focus on targeted drug delivery. Different targeting strategies for manipulating and inhibiting MMPs for the treatment of cancer are discussed. MMPs are upregulated at all stages of expression in cancers. Different MMP subtypes have shown significant targeting applicability at the genetic, protein, and activity levels in both physiological and pathophysiological conditions in a variety of cancers. The expression of MMPs significantly increases at advanced cancer stages, which can be used for controlled release in cancers in advance stages. Methods: Moreover, this study presents the synthesis and characteristics of a new and highly selective inhibitor against MMP-7 and discusses its applications in targeted drug delivery systems for therapeutics and diagnostics modalities. Results: Our findings showed that the structure of the inhibitor P3’ side chains play the crucial role in developing an optimized MMP-7 inhibitor with high selectivity and significant degradation activities against ECM. Conclusion: Optimized NDC can serve as a highly potent and selective inhibitor against MMP-7 following screening and optimization of the P3’ side chains, with a Ki of 38.6 nM and an inhibitory selectivity of 575 of MMP-7 over MMP-1.

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