scholarly journals Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

2017 ◽  
Vol 13 ◽  
pp. 2521-2534 ◽  
Author(s):  
Artur Jabłoński ◽  
Yannic Fritz ◽  
Hans-Achim Wagenknecht ◽  
Rafał Czerwieniec ◽  
Tytus Bernaś ◽  
...  
Keyword(s):  
Self Assembly ◽  
Crystal Structure Analysis ◽  
Buffer Solution ◽  
Self Assembling ◽  
Canonical Base ◽  
Thymine Adenine ◽  
Single Crystal Structure Analysis ◽  
Carbonyl Function ◽  
Dual Staining ◽  
Adenine Derivative

Fluorescent pyrene–linker–nucleobase (nucleobase = thymine, adenine) conjugates with carbonyl and hydroxy functionalities in the linker were synthesized and characterized. X-ray single-crystal structure analysis performed for the pyrene–C(O)CH2CH2–thymine (2) conjugate reveals dimers of molecules 2 stabilized by hydrogen bonds between the thymine moieties. The photochemical characterization showed structure-dependent fluorescence properties of the investigated compounds. The conjugates bearing a carbonyl function represent weak emitters as compared to compounds with a hydroxy function in the linker. The self-assembly properties of pyrene nucleobases were investigated in respect to their binding to single and double strand oligonucleotides in water and in buffer solution. In respect to the complementary oligothymidine T10 template in water, compounds 3 and 5 both show a self-assembling behavior according to canonical base–base pairing. However, in buffer solution, derivative 5 was much more effective than 3 in binding to the T10 template. Furthermore the adenine derivative 5 binds to the double-stranded (dA)10–T10 template with a self-assembly ratio of 112%. Such a high value of a self-assembly ratio can be rationalized by a triple-helix-like binding, intercalation, or a mixture of both. Remarkably, compound 5 also shows dual staining pattern in living HeLa cells. Confocal microscopy confirmed that 5 predominantly stains mitochondria but it also accumulates in the nucleoli of the cells.

Factors Affecting Molecular Self-Assembly and Its Mechanism

2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Molecular Engineering ◽  
Molecular Structures ◽  
Polymer Science ◽  
New Approach ◽  
Factors Affecting ◽  
Dna Structures ◽  
Self Assembling ◽  
Wide Range

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.

Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Light Scattering ◽  
Chain Length ◽  
Self Assembly ◽  
The Self ◽  
Ionic Charge ◽  
Self Assembling ◽  
Biophysical Techniques

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.

Self-assembling behaviour of a modified aromatic amino acid in competitive medium

Soft Matter ◽  
2020 ◽  
Vol 16 (28) ◽  
pp. 6599-6607 ◽  
Author(s):  
Pijush Singh ◽  
Souvik Misra ◽  
Nayim Sepay ◽  
Sanjoy Mondal ◽  
Debes Ray ◽  
...  
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acid ◽  
Photophysical Properties ◽  
Solvent Mixture ◽  
The Self ◽  
Solvent Ratio ◽  
Self Assembling

The self-assembly and photophysical properties of 4-nitrophenylalanine (4NP) are changed with the alteration of solvent and final self-assembly state of 4NP in competitive solvent mixture and are dictated by the solvent ratio.

Sticky ends in a self-assembling ABA triblock copolymer: the role of ureas in stimuli-responsive hydrogels

2019 ◽  
Vol 4 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Ryan T. Shafranek ◽  
Joel D. Leger ◽  
Song Zhang ◽  
Munira Khalil ◽  
Xiaodan Gu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Viscoelastic Properties ◽  
Triblock Copolymer ◽  
Thermal Response ◽  
Stimuli Responsive ◽  
Self Assembling ◽  
Polymeric Hydrogels ◽  
Aba Triblock Copolymer ◽  
Responsive Hydrogels

Directed self-assembly in polymeric hydrogels allows tunability of thermal response and viscoelastic properties.

scholarly journals A New Hope: Self-Assembling Peptides with Antimicrobial Activity

Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 166 ◽  
Author(s):  
Lucia Lombardi ◽  
Annarita Falanga ◽  
Valentina Del Genio ◽  
Stefania Galdiero
Keyword(s):  
Self Assembly ◽  
Biomedical Applications ◽  
High Specificity ◽  
Antibacterial Activities ◽  
Mechanisms Of Action ◽  
Great Promise ◽  
Functional Nanomaterials ◽  
Self Assembling ◽  
Low Toxicity ◽  
Bio Compatibility

Peptide drugs hold great promise for the treatment of infectious diseases thanks to their novel mechanisms of action, low toxicity, high specificity, and ease of synthesis and modification. Naturally developing self-assembly in nature has inspired remarkable interest in self-assembly of peptides to functional nanomaterials. As a matter of fact, their structural, mechanical, and functional advantages, plus their high bio-compatibility and bio-degradability make them excellent candidates for facilitating biomedical applications. This review focuses on the self-assembly of peptides for the fabrication of antibacterial nanomaterials holding great interest for substituting antibiotics, with emphasis on strategies to achieve nano-architectures of self-assembly. The antibacterial activities achieved by these nanomaterials are also described.

scholarly journals Multiscale additive manufacturing of polymers using 3D photo-printable self-assembling ionic liquid monomers

2019 ◽  
Vol 4 (3) ◽  
pp. 580-585 ◽  
Author(s):  
Bineh G. Ndefru ◽  
Bryan S. Ringstrand ◽  
Sokhna I.-Y. Diouf ◽  
Sönke Seifert ◽  
Juan H. Leal ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Additive Manufacturing ◽  
Self Assembly ◽  
Low Cost ◽  
Low Resolution ◽  
Top Down ◽  
Bottom Up ◽  
Cost Approach ◽  
Self Assembling ◽  
Nanoscale Features

Combining bottom-up self-assembly with top-down 3D photoprinting affords a low cost approach for the introduction of nanoscale features into a build with low resolution features.

Self Assembling Nanostructured Delivery Vehicles for Biochemically Reactive Pairs

1994 ◽  
Vol 351 ◽  
Author(s):  
Nir Kossovsky ◽  
A. Gelman ◽  
H.J. Hnatyszyn ◽  
E. Sponsler ◽  
G.-M. Chow
Keyword(s):  
Physical Properties ◽  
Self Assembly ◽  
Materials Science ◽  
Technology Development ◽  
Biological Behavior ◽  
X Ray Diffraction ◽  
Self Assembling ◽  
Transmission Electron ◽  
Carbon Ceramic

ABSTRACTIntrigued by the deceptive simplicity and beauty of macromolecular self-assembly, our laboratory began studying models of self-assembly using solids, glasses, and colloidal substrates. These studies have defined a fundamental new colloidal material for supporting members of a biochemically reactive pair.The technology, a molecular transportation assembly, is based on preformed carbon ceramic nanoparticles and self assembled calcium-phosphate dihydrate particles to which glassy carbohydrates are then applied as a nanometer thick surface coating. This carbohydrate coated core functions as a dehydroprotectant and stabilizes surface immobilized members of a biochemically reactive pair. The final product, therefore, consists of three layers. The core is comprised of the ceramic, the second layer is the dehydroprotectant carbohydrate adhesive, and the surface layer is the biochemically reactive molecule for which delivery is desired.We have characterized many of the physical properties of this system and have evaluated the utility of this delivery technology in vitro and in animal models. Physical characterization has included standard and high resolution transmission electron microscopy, electron and x-ray diffraction and ζ potential analysis. Functional assays of the ability of the system to act as a nanoscale dehydroprotecting delivery vehicle have been performed on viral antigens, hemoglobin, and insulin. By all measures at present, the favorable physical properties and biological behavior of the molecular transportation assembly point to an exciting new interdisciplinary area of technology development in materials science, chemistry and biology.

scholarly journals A Self-Assembling Amphiphilic Peptide Dendrimer-Based Drug Delivery System for Cancer Therapy

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1092
Author(s):  
Dandan Zhu ◽  
Huanle Zhang ◽  
Yuanzheng Huang ◽  
Baoping Lian ◽  
Chi Ma ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Delivery ◽  
Drug Resistance ◽  
Cancer Therapy ◽  
Self Assembly ◽  
Cancer Drug ◽  
Acquired Drug Resistance ◽  
Self Assembling ◽  
Amphiphilic Peptide ◽  
Peptide Dendrimer

Despite being a mainstay of clinical cancer treatment, chemotherapy is limited by its severe side effects and inherent or acquired drug resistance. Nanotechnology-based drug-delivery systems are widely expected to bring new hope for cancer therapy. These systems exploit the ability of nanomaterials to accumulate and deliver anticancer drugs at the tumor site via the enhanced permeability and retention effect. Here, we established a novel drug-delivery nanosystem based on amphiphilic peptide dendrimers (AmPDs) composed of a hydrophobic alkyl chain and a hydrophilic polylysine dendron with different generations (AmPD KK2 and AmPD KK2K4). These AmPDs assembled into nanoassemblies for efficient encapsulation of the anti-cancer drug doxorubicin (DOX). The AmPDs/DOX nanoformulations improved the intracellular uptake and accumulation of DOX in drug-resistant breast cancer cells and increased permeation in 3D multicellular tumor spheroids in comparison with free DOX. Thus, they exerted effective anticancer activity while circumventing drug resistance in 2D and 3D breast cancer models. Interestingly, AmPD KK2 bearing a smaller peptide dendron encapsulated DOX to form more stable nanoparticles than AmPD KK2K4 bearing a larger peptide dendron, resulting in better cellular uptake, penetration, and anti-proliferative activity. This may be because AmPD KK2 maintains a better balance between hydrophobicity and hydrophilicity to achieve optimal self-assembly, thereby facilitating more stable drug encapsulation and efficient drug release. Together, our study provides a promising perspective on the design of the safe and efficient cancer drug-delivery nanosystems based on the self-assembling amphiphilic peptide dendrimer.

A Biological System Producing a Self-Assembling Cholesteric Protein Liquid Crystal

1971 ◽  
Vol 8 (1) ◽  
pp. 93-109
Author(s):  
A. C. NEVILLE ◽  
B. M. LUKE
Keyword(s):  
Liquid Crystal ◽  
Electron Density ◽  
Electron Micrographs ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
Density Variation ◽  
Self Assembling ◽  
The Matrix ◽  
Electron Density Variation ◽  
Helicoidal Structure

The protein in the oothecal glands of praying mantids (Sphodromantis tenuidentata, Miomantis monacha) exists in the form of lamellar liquid crystalline spherulites, which coalesce as they flow out of a punctured gland tubule. Electron micrographs of sections of these spherulites after fixation show parabolic patterns of an electron-light component, set in a continuous matrix of protein. Such patterns arise in helicoidal systems (e.g. arthropod cuticle) and microdensitometric scans of the matrix show a rhythmical electron-density variation consistent with helicoidal structure. Double spiral patterns identical to those seen in liquid crystal spherulites are illustrated. These properties resemble those of cholesteric liquid crystals. The constructional units appear to be molecular rather than fibrillar as described by previous authors. The helicoidal architecture arises by self-assembly in the gland lumen. Lamellar surface structures self-assembled spontaneously on glass coverslips when the protein was left to stand for several days. When heated to 55 °C, the birefringent liquid crystalline protein abruptly changes to an isotropic gel, with associated loss of parabolic patterning in electron micrographs and of the rhythmical electron-density variation on microdensitometric scans. This behaviour is compared to the formation of gelatin from collagen, in terms of the randomization of an originally ordered secondary structure.

Tandem Molecular Self-assembly for Selective Lung Cancer Therapy with Two Orders of Magnitude Increase in Efficiency

Nanoscale ◽  
2021 ◽  
Author(s):  
Debin Zheng ◽  
Jingfei Liu ◽  
Yinghao Ding ◽  
Limin Xie ◽  
Yingying Zhang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cancer Therapy ◽  
Anticancer Drugs ◽  
Self Assembly ◽  
Therapeutic Efficacy ◽  
Self Assembling ◽  
Lung Cancer Therapy ◽  
Magnitude Increase

In situ self-assembling of prodrug molecules into nanomedicine can elevate the therapeutic efficacy of anticancer medications by enhancing the targeting and enrichment of anticancer drugs at tumor sites. However, the...

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