scholarly journals SERS Investigation on Oligopeptides Used as Biomimetic Coatings for Medical Devices

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 959
Author(s):  
Michele Di Foggia ◽  
Vitaliano Tugnoli ◽  
Stefano Ottani ◽  
Monica Dettin ◽  
Annj Zamuner ◽  
...  
Keyword(s):  
Medical Devices ◽  
Spatial Arrangement ◽  
Amide Bond ◽  
Substitution Effects ◽  
Aliphatic Chain ◽  
Molecular Systems ◽  
Self Assembling ◽  
Surface Enhanced Raman ◽  
Colloid Nanoparticles ◽  
Gamma Irradiated

The surface-enhanced Raman scattering (SERS) spectra of three amphiphilic oligopeptides derived from EAK16 (AEAEAKAK)2 were examined to study systematic amino acid substitution effects on the corresponding interaction with Ag colloidal nanoparticles. Such self-assembling molecular systems, known as “molecular Lego”, are of particular interest for their uses in tissue engineering and as biomimetic coatings for medical devices because they can form insoluble macroscopic membranes under physiological conditions. Spectra were collected for both native and gamma-irradiated samples. Quantum mechanical data on two of the examined oligopeptides were also obtained to clarify the assignment of the prominent significative bands observed in the spectra. In general, the peptide–nanoparticles interaction occurs through the COO− groups, with the amide bond and the aliphatic chain close to the colloid surface. After gamma irradiation, mimicking a free oxidative radical attack, the SERS spectra of the biomaterials show that COO− groups still provide the main peptide–nanoparticle interactions. However, the spatial arrangement of the peptides is different, exhibiting a systematic decrease in the distance between aliphatic chains and colloid nanoparticles.

Synthesis, Self-Assembling and Redox Properties of 2-[(ω-Sulfanylalkyl)amino]-1,4-naphthoquinones

2006 ◽  
Vol 71 (9) ◽  
pp. 1383-1391 ◽  
Author(s):  
Maryte Kažemekaite ◽  
Vilma Railaite ◽  
Arunas Bulovas ◽  
Zita Talaikyte ◽  
Gediminas Niaura ◽  
...  
Keyword(s):  
Reduction Process ◽  
Spectroscopic Studies ◽  
Self Assembled Monolayers ◽  
Raman Spectroscopic ◽  
Self Assembling ◽  
Electrochemical Parameters ◽  
Surface Enhanced ◽  
Assembled Monolayers ◽  
Surface Enhanced Raman ◽  
Group Form

The newly synthesized 1,4-naphthoquinones linked via nitrogen atom to a short chain with terminal sulfanyl group form self-assembled monolayers on gold. The main electrochemical parameters of the monolayers were determined by cyclic voltammetry. Combined voltammetric and in situ Fourier-transform surface-enhanced Raman spectroscopic studies of the Au electrode modified with the title compounds clearly evidence that naphthoquinone group transforms into naphthalenediol during a reduction process.

scholarly journals Homodyne dynamic light scattering in supramolecular polymer solutions: anomalous oscillations in intensity correlation function

Soft Matter ◽  
2020 ◽  
Vol 16 (12) ◽  
pp. 2971-2993
Author(s):  
Emilie Moulin ◽  
Irina A. Nyrkova ◽  
Nicolas Giuseppone ◽  
Alexander N. Semenov ◽  
Eric Buhler
Keyword(s):  
Correlation Function ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Polymer Solutions ◽  
Supramolecular Polymer ◽  
Intensity Correlation ◽  
Molecular Systems ◽  
Self Assembling ◽  
Intensity Correlation Function

Light-sensitive self-assembling molecular systems display well-defined and persistent oscillations in the homodyne intensity correlation function after irradiation.

scholarly journals SURFACE ENHANCED RAMAN SPECTRUM OF NANOMETRIC MOLECULAR SYSTEMS

2005 ◽  
Vol 50 (4) ◽  
Author(s):  
P. LEYTO ◽  
P.A. LIZAMA-VERGARA ◽  
M.M. CAMPOS-VALLETTE ◽  
M.I. BECKER ◽  
E. CLAVIJO ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Molecular Systems ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

All-or-none switching of photon upconversion in self-assembled organogel systems

2017 ◽  
Vol 196 ◽  
pp. 305-316 ◽  
Author(s):  
Pengfei Duan ◽  
Deepak Asthana ◽  
Takuya Nakashima ◽  
Tsuyoshi Kawai ◽  
Nobuhiro Yanai ◽  
...  
Keyword(s):  
Self Assembly ◽  
Room Temperature ◽  
Stimuli Responsive ◽  
Molecular Systems ◽  
Controlled Assembly ◽  
Outstanding Problem ◽  
Self Assembling ◽  
New Strategy ◽  
Donor Acceptor

Aggregation-induced photon upconversion (iPUC) based on a triplet–triplet annihilation (TTA) process is successfully developed via controlled self-assembly of donor–acceptor pairs in organogel nanoassemblies. Although segregation of donor from acceptor assemblies has been an outstanding problem in TTA-based UC and iPUC, we resolved this issue by modifying both the triplet donor and aggregation induced emission (AIE)-type acceptor with glutamate-based self-assembling moieties. These donors and acceptors co-assemble to form organogels without segregation. Interestingly, these donor–acceptor binary gels show upconversion at room temperature but the upconversion phenomena were lost upon dissolution of the gels on heating. The observed changes in TTA-UC emission were thermally reversible, reflecting the controlled assembly/disassembly of the binary molecular systems. The observed on/off ratio of UC emission was much higher than that of the aggregation-induced fluorescence of the acceptor, which highlights the important role of iPUC, i.e., multi-exciton TTA for photoluminescence switching. This work bridges iPUC and supramolecular chemistry and provides a new strategy for designing stimuli-responsive upconversion systems.

scholarly journals Solubilization of Paclitaxel by Self-Assembled Amphiphilic Phospholipid-Mimetic Polymers with Varied Hydrophobicity

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2805
Author(s):  
Chie Kojima ◽  
Tomoka Hirose ◽  
Risa Katayama ◽  
Akikazu Matsumoto
Keyword(s):  
Medical Devices ◽  
Drug Delivery Systems ◽  
Drug Action ◽  
The Self ◽  
Butyl Methacrylate ◽  
Random Copolymers ◽  
Coating Agent ◽  
Self Assembling ◽  
Dodecyl Methacrylate ◽  
Self Assembled

2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers have been used as a coating agent on medical devices and as a carrier in drug delivery systems (DDSs). Paclitaxel (PTX) is a water-insoluble anticancer drug whose solubilizer is necessary for administration. Block and random copolymers composed of hydrophilic MPC and butyl methacrylate, named PMB, show different properties, depending on the polymer sequence and MPC content. In the present study, we used amphiphilic MPC polymers comprising hydrophobic dodecyl methacrylate (DMA). The self-assembling properties and PTX solubilization of random and block poly(MPC-co-DMA)s (rPMDs and bPMDs) with different compositions were examined and compared. rPMDs with high DMA content formed large and relatively loose self-assembled structures, which solubilized PTX. However, bPMDs formed small and compact self-assembled structures with poor PTX solubilization. PTX solubilized by PMB with small and loose self-assembled structures showed efficient drug action, similar to free PTX; however, rPMDs fell short of demonstrating PTX efficiency. Our results suggest that the self-assembling properties and the hydrophobicity of amphiphilic MPC polymers largely affect PTX solubilization as well as drug action, which is required to be controlled by the polymer sequence, as well as the structure and composition of the hydrophobic monomer for efficient DDS.

scholarly journals Resolving sub-angstrom ambient motion through reconstruction from vibrational spectra

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jack Griffiths ◽  
Tamás Földes ◽  
Bart de Nijs ◽  
Rohit Chikkaraddy ◽  
Demelza Wright ◽  
...  
Keyword(s):  
Single Molecule ◽  
Imaging Techniques ◽  
Surface Enhanced Raman Spectroscopy ◽  
Atomic Scale ◽  
Single Atom ◽  
Ambient Conditions ◽  
Molecular Systems ◽  
Surface Enhanced Raman ◽  
Metal Organic ◽  
Molecule Interactions

AbstractMetal/organic-molecule interactions underpin many key chemistries but occur on sub-nm scales where nanoscale visualisation techniques tend to average over heterogeneous distributions. Single molecule imaging techniques at the atomic scale have found it challenging to track chemical behaviour under ambient conditions. Surface-enhanced Raman spectroscopy can optically monitor the vibrations of single molecules but understanding is limited by the complexity of spectra and mismatch between theory and experiment. We demonstrate that spectra from an optically generated metallic adatom near a molecule of interest can be inverted into dynamic sub-Å metal-molecule interactions using a comprehensive model, revealing anomalous diffusion of a single atom. Transient metal-organic coordination bonds chemically perturb molecular functional groups > 10 bonds away. With continuous improvements in computational methods for modelling large and complex molecular systems, this technique will become increasingly applicable to accurately tracking more complex chemistries.

scholarly journals Controlled release of targeted chemotherapeutic drug dabrafenib for melanoma cancers monitored using surface-enhanced Raman scattering (SERS) spectroscopy

2018 ◽  
Vol 7 (1) ◽  
pp. 18-27 ◽  
Author(s):  
Logan Running ◽  
Ricardo Espinal ◽  
Maria Hepel
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Raman Scattering ◽  
Surface Enhanced Raman Scattering ◽  
Drug Binding ◽  
Amide Bond ◽  
High Signal ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

The advanced skin cancer melanoma, which is primarily caused by the mutation of BRAF gene, has a high mortality rate and requires high doses of chemotherapeutic drugs. To mitigate the drug toxicity to healthy cells and other side effects, the development of alternative modes of treatment has been extensively sought after. Herein, we describe a new targeted drug delivery system with controlled release, based on nanoparticle nanocarriers functionalized with folate and transferrin ligands for recognition of the respective receptors overexpressed in cancer cell membrane. We have investigated the immobilization of a new drug dabrafenib onto the nanocarriers and its controlled release, aided with surface-enhanced Raman scattering (SERS) spectroscopy which affords ultra-sensitive in situ measurement ability owing to the high signal amplification, associated with strong plasmonic fields of the nanocarrier gold nanoparticle (AuNP) cores. The nanocarriers were equipped with Raman reporters: mercaptobenzoic acid (MBA) and para-aminothiophenol (PATP) forming a mixed thiolate monolayer shell on AuNPs. The dabrafenib was covalently attached to MBA via an amide bond which is pH sensitive and enables the drug release at lower pH encountered in cancer cells. This arrangement in the drug binding to the nanocarrier protects the dabrafenib amine group against deactivation until the drug release in the target tumor cells.

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