Molecular nanotechnology

Résumé

Molecular nanotechnology (MNT) is a technology based on the ability to build structures to complex, atomic specifications by means of mechanosynthesis. This is distinct from nanoscale materials. Based on Richard Feynman's vision of miniature factories using nanomachines to build complex products (including additional nanomachines), this advanced form of nanotechnology (or molecular manufacturing) would make use of positionally-controlled mechanosynthesis guided by molecular machine systems. MNT would involve combining physical principles demonstrated by biophysics, chemistry, other nanotechnologies, and the molecular machinery of life with the systems engineering principles found in modern macroscale factories. Introduction While conventional chemistry uses inexact processes obtaining inexact results, and biology exploits inexact processes to obtain definitive results, molecular nanotechnology would employ original definitive processes to obtain definitive results. The de

Source officielle

https://en.wikipedia.org/wiki/Molecular_nanotechnology

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Publications associées (21)

Publications associées

Chargement

Personnes associées (1)

Personnes associées

Chargement

Unités associées (1)

Unités associées

Chargement

Concepts associés (14)

Concepts associés

Chargement

Cours associés (5)

Cours associés

Chargement

Séances de cours associées (5)

Séances de cours associées

Chargement

Comparative Performance of Different Nanostructured Electrochemical Sensors on Insulin Detection

Sandro Carrara, Giovanni De Micheli, Lucia Grassi

New advancements in the management of type I diabetic patients (T1DM) call for a new generation of monitoring systems based upon an array of metabolic biosensors including sensors for insulin detection. Blood insulin values are always less than 270 pM; therefore, specifically designed insulin sensors have to provide a limit of detection in the range of few pico-molar units. At present, electrochemical sensors are one of the best options to provide low-cost technologies for diabetes mellitus monitoring and treatment. Moreover, modern nanotechnology permits to improve further their performances by providing new materials, structured at the nanoscale (i.e., carbon nanotubes), which alter the original sensor properties when used for both in vivo and in vitro biosensing applications. A recent article in literature has proposed a solution based on electrochemical sensors that promise performances in line with above-mentioned insulin detection requirements. However, data presented in this paper show that such a promise is still overestimated, and an electro-chemical sensor capable of insulin detection within the physiological range is still beyond the present state of the art even when adopting nanostructured working electrodes.

2013

Chargement

Preparation and characterization of Poly(Ethylene Glycol)/gamma-CD Polyrotaxanes using beta-CD derivatives as a capping reagent

Blaise Tardy

As living systems understanding got better, as life could be modeled in a batch, using immortalized cells, researches in fundamental sciences found startling applications of advanced techniques on living systems. As the biomaterial field developed various molecules were found to have very interesting applications on living systems. Polyrotaxane is one of these particularly interesting molecules. It is a non covalently bonded molecular necklace produced by the threading of cyclic molecules onto a linear polymer in order to form a pseudopolyrotaxane, the capping of this pseudopolyrotaxane to avoid de-threading of the cyclic compounds forms a polyrotaxane. This compound has already proven its versatility through various application including drug delivery systems, DNA delivery agent, molecular machine, hydrogel building block, resin stabilizer and a lot more. Cyclodextrins (CDs) and Polyester are known to form a pseudopolyrotaxane. CDs are composed of 6 to 8 glucopyranose forming a toroid shaped molecule that can contain different molecules depending on the solvent, experimental conditions and the number of sugar subunits. In this project an attempt has been made to synthesize a special type of polyrotaxane that would allow the whole complex to bare a higher degree of freedom compared to the ones currently documented. In order to do so the widest CD has been used (Gamma-CD, GCD), the chosen host has been poly(ethylene glycol) (PEG) chains of varying molecular weight and the capping reagent used was beta-CD derivatives. Furthermore since current literature hasn't documented it so well and its properties are essential to this study, some more characterization of the PEG/GCD pseudopolyrotaxane has been made. The Macromolecules have been characterized by maldi tof mass spectroscopy(MALDI-T-MS), electro spray ionization (ESI) mass detection, X-ray diffraction(XRD), gel phase chromatography (GPC) and liquid Nuclear magnetic resonance (NMR). The beta CD and poly(ethylene glycol) derivatives have been characterized using Fourier transform infra red spectroscopy (FTIR), NMR, MALDI-Toff MS, ESI and thin layer Chromatography (TLC)

2009

Chargement

Cholera pandemics have been affecting humankind for centuries and are still considered a major public health problem, especially in regions around the world with poor access to clean water and sanitation. Cholera pandemics are caused by a specific lineage of the bacterial pathogen Vibrio cholerae, while the vast majority of the species' diversity is found in innocuous environmental strains. The complete set of factors that allowed the emergence and success of the pandemic lineage are still unknown. Importantly, most V. cholerae strains are adapted to aquatic habitats and trigger their behavior accordingly. The aim of this thesis was therefore to gain a better understanding of what is special about the pandemic lineage when contrasted to its environmental counterparts. Specifically, we investigated environmentally important bacterial behaviors in a comparative framework. Firstly, considering the relevance of eukaryotic predation in shaping bacterioplankton structure, we investigated possible strategies used by V. cholerae to avoid grazing by the predatory amoeba Dictyostelium discoideum. We observed that V. cholerae was able to rapidly intoxicate amoebae and that the intoxication dynamics differed when caused by pandemic or environmental strains. Secondly, we compared a well-conserved set of mobile genetic elements (MGEs) of the pandemic lineage, many of which are involved in key aspects of cholera pathogenesis, with the respective counterparts of environmental strains. To do so, we sequenced and de novo assembled the genomes of fifteen environmental isolates and thoroughly described their mobilome. Moreover, transcription profiling demonstrated that most genes located on these MGEs are expressed. Thirdly, we compared environmental and pandemic strains regarding their potential to kill bacterial competitors and to defend themselves against protozoan predation. Specifically, we assessed the role of two molecular weapons: the pore-forming toxin hemolysin and the type six secretion system (T6SS), a molecular killing device that delivers effector toxins into target cells. While environmental strains keep both of these weapons constitutively active, pandemic strains employ regulatory mechanisms to control their expression. We observed that all environmental V. cholerae isolates used their T6SS to efficiently outcompete prey bacteria, while only two clades of the environmental isolates also intoxicated eukaryotic amoebae. Furthermore, we performed a meticulous in silico characterization of the effector and immunity proteins carried by the environmental strains and showed in pairwise killing experiments that a high degree of immunity protein identity was required to allow the strains' coexistence. Finally, we addressed the phenomenon of T6SS constitutive activity in non-pandemic V. cholerae strains, which has puzzled the field since the T6SS' discovery in 2006. Using a transformation-based strain library, we uncovered a genomic region that controls T6SS activity. In summary, work developed in this thesis contributes to a better understanding of V. cholerae's evolution from an innocuous inhabitant of aquatic environments to a pandemic-causing human pathogen.

EPFL2021

Chargement

EPFL2021

Preparation and characterization of Poly(Ethylene Glycol)/gamma-CD Polyrotaxanes using beta-CD derivatives as a capping reagent

Blaise Tardy

2009