scholarly journals Controlling the Kinetics of an Enzymatic Reaction through Enzyme or Substrate Confinement into Lipid Mesophases with Tunable Structural Parameters

2020 ◽  
Vol 21 (14) ◽  
pp. 5116
Author(s):  
Marco Mendozza ◽  
Arianna Balestri ◽  
Costanza Montis ◽  
Debora Berti
Keyword(s):  
Reaction Kinetics ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
Structural Parameters ◽  
Enzymatic Reaction ◽  
X Ray Scattering ◽  
Nitrophenyl Phosphate ◽  
Vis Spectroscopy ◽  
Kinetics Of ◽  
Enzyme Alkaline Phosphatase

Lipid liquid crystalline mesophases, resulting from the self-assembly of polymorphic lipids in water, have been widely explored as biocompatible drug delivery systems. In this respect, non-lamellar structures are particularly attractive: they are characterized by complex 3D architectures, with the coexistence of hydrophobic and hydrophilic regions that can conveniently host drugs of different polarities. The fine tunability of the structural parameters is nontrivial, but of paramount relevance, in order to control the diffusive properties of encapsulated active principles and, ultimately, their pharmacokinetics and release. In this work, we investigate the reaction kinetics of p-nitrophenyl phosphate conversion into p-nitrophenol, catalysed by the enzyme Alkaline Phosphatase, upon alternative confinement of the substrate and of the enzyme into liquid crystalline mesophases of phytantriol/H2O containing variable amounts of an additive, sucrose stearate, able to swell the mesophase. A structural investigation through Small-Angle X-ray Scattering, revealed the possibility to finely control the structure/size of the mesophases with the amount of the included additive. A UV–vis spectroscopy study highlighted that the enzymatic reaction kinetics could be controlled by tuning the structural parameters of the mesophase, opening new perspectives for the exploitation of non-lamellar mesophases for confinement and controlled release of therapeutics.

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

Enzymatic Reaction Kinetics of Papain-Extracted Collagen from Bighead Carp Scales

2015 ◽  
Vol 727-728 ◽  
pp. 56-60
Author(s):  
Min Li ◽  
Liu Meng Chen ◽  
Bo Quan Jiang
Keyword(s):  
Reaction Kinetics ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Raw Material ◽  
Bighead Carp ◽  
Fish Waste ◽  
Biomedical Material ◽  
Production Output ◽  
And Control ◽  
Kinetics Of

Collagen, as an important biomedical material, has been widely used in medical industry. Fish waste (scales, skins, bones, fins and swim bladders) is a kind of newly developed alternative collagen raw material.This paper uesd papain as enzyme and local bighead fish scales as raw material to extract collagen. More attention was paid to the study on enzymatic reaction kinetics of papain-extracted collagen. The results showed that two kinds of kinetic models(Michaelis-Menten equations and exponential type dynamic equations) at 20, 25 and 28°C were established, respectively and experimentally proved to be basically in agreement with the actual values. These models have a great significance to predict, adjust and control the reaction rate and production output under different conditions.

Programmable Dynamic Steady States in ATP-Driven Non-Equilibrium DNA Systems

2019 ◽  
Author(s):  
Laura Heinen ◽  
Andreas Walther
Keyword(s):  
Self Assembly ◽  
Soft Matter ◽  
Enzymatic Reaction ◽  
Reaction Network ◽  
Steady States ◽  
Supramolecular Systems ◽  
Kinetics Of ◽  
Average Bond ◽  
Full Synchronization ◽  
Non Equilibrium

<div><div><div><p>Inspired by the dynamics of the dissipative self-assembly of microtubules, chemically fueled synthetic systems with transient lifetimes are emerging for non-equilibrium materials design. However, realizing programmable or even adaptive structural dynamics has proven challenging because it requires synchronization of energy uptake and dissipation events within true steady states, which remains difficult to orthogonally control in supramolecular systems. Here, we demonstrate full synchronization of both events by ATP-fueled activation and dynamization of covalent DNA bonds via an enzymatic reaction network of concurrent ligation and cleavage. Critically, the average bond ratio and the frequency of bond exchange are imprinted into the energy dissipation kinetics of the network and tunable through its constituents. We introduce temporally and structurally programmable dynamics by polymerization of transient, dynamic covalent DNA polymers with adaptive steady-state properties in dependence of ATP fuel and enzyme concentrations. This approach enables generic access to non-equilibrium soft matter systems with adaptive and programmable dynamics.</p></div></div></div>

scholarly journals Self-assembly of block copolymers under non-isothermal annealing conditions as revealed by grazing-incidence small-angle X-ray scattering

2020 ◽  
Vol 27 (5) ◽  
pp. 1278-1288 ◽  
Author(s):  
Marta Fernández-Regúlez ◽  
Eduardo Solano ◽  
Laura Evangelio ◽  
Steven Gottlieb ◽  
Christian Pinto-Gómez ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Small Angle ◽  
Self Assembly ◽  
Isothermal Annealing ◽  
Grazing Incidence ◽  
The Self ◽  
X Ray ◽  
Annealing Conditions ◽  
X Ray Scattering ◽  
Kinetics Of

An accurate knowledge of the parameters governing the kinetics of block copolymer self-assembly is crucial to model the time- and temperature-dependent evolution of pattern formation during annealing as well as to predict the most efficient conditions for the formation of defect-free patterns. Here, the self-assembly kinetics of a lamellar PS-b-PMMA block copolymer under both isothermal and non-isothermal annealing conditions are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS) experiments with a novel modelling methodology that accounts for the annealing history of the block copolymer film before it reaches the isothermal regime. Such a model allows conventional studies in isothermal annealing conditions to be extended to the more realistic case of non-isothermal annealing and prediction of the accuracy in the determination of the relevant parameters, namely the correlation length and the growth exponent, which define the kinetics of the self-assembly.

scholarly journals Concentration Effects on the Dynamics of Liquid Crystalline Self-Assembly: Time-Resolved X-ray Scattering Studies

2011 ◽  
Vol 115 (11) ◽  
pp. 2176-2183 ◽  
Author(s):  
Marcel Petri ◽  
Andreas Menzel ◽  
Oliver Bunk ◽  
Gerhard Busse ◽  
Simone Techert
Keyword(s):  
Self Assembly ◽  
Liquid Crystalline ◽  
Concentration Effects ◽  
Time Resolved ◽  
X Ray ◽  
Assembly Time ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Confined self-assembly of cellulose nanocrystals in a shrinking droplet

Soft Matter ◽  
2015 ◽  
Vol 11 (26) ◽  
pp. 5374-5380 ◽  
Author(s):  
Fernando Jativa ◽  
Christina Schütz ◽  
Lennart Bergström ◽  
Xuehua Zhang ◽  
Bernd Wicklein
Keyword(s):  
Cellulose Nanocrystals ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
Dissolution Kinetics ◽  
Crystalline Phases ◽  
Liquid Crystalline Phases ◽  
Kinetics Of

Self-assembly of cellulose nanocrystals in a shrinking droplet was studied. The evolution of liquid crystalline phases and the morphology of the resultant microbeads can be controlled by the dissolution kinetics of the droplet.

scholarly journals Programmable dynamic steady states in ATP-driven nonequilibrium DNA systems

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw0590 ◽  
Author(s):  
Laura Heinen ◽  
Andreas Walther
Keyword(s):  
Self Assembly ◽  
Soft Matter ◽  
Enzymatic Reaction ◽  
Reaction Network ◽  
Steady States ◽  
Supramolecular Systems ◽  
Dissipation Kinetics ◽  
Kinetics Of ◽  
Average Bond ◽  
Full Synchronization

Inspired by the dynamics of the dissipative self-assembly of microtubules, chemically fueled synthetic systems with transient lifetimes are emerging for nonequilibrium materials design. However, realizing programmable or even adaptive structural dynamics has proven challenging because it requires synchronization of energy uptake and dissipation events within true steady states, which remains difficult to orthogonally control in supramolecular systems. Here, we demonstrate full synchronization of both events by ATP-fueled activation and dynamization of covalent DNA bonds via an enzymatic reaction network of concurrent ligation and cleavage. Critically, the average bond ratio and the frequency of bond exchange are imprinted into the energy dissipation kinetics of the network and tunable through its constituents. We introduce temporally and structurally programmable dynamics by polymerization of transient, dynamic covalent DNA polymers with adaptive steady-state properties in dependence of ATP fuel and enzyme concentrations. This approach enables generic access to nonequilibrium soft matter systems with adaptive and programmable dynamics.

scholarly journals Controlled Kinetics of On-Surface Dehydrogenation using a Low-Energy Electron Beam

2021 ◽  
Author(s):  
Anton Makoveev ◽  
Pavel Procházka ◽  
Azin Shahsavar ◽  
Lukáš Kormoš ◽  
Tomáš Krajňák ◽  
...  
Keyword(s):  
Electron Beam ◽  
Reaction Kinetics ◽  
Chemical Reaction ◽  
Self Assembly ◽  
Reaction Rate ◽  
Low Energy ◽  
Energy Electron ◽  
Chemical Reaction Kinetics ◽  
Low Energy Electron ◽  
Kinetics Of

Abstract Self-assembly and on-surface synthesis are vital strategies used for fabricating surface-confined 1D or 2D supramolecular nanoarchitectures with atomic precision. In many systems, the resulting structure is determined by kinetics of processes involved, i.e., reaction rate, on-surface diffusion, nucleation, and growth, all of which are typically governed by temperature. However, other external factors have been only scarcely harnessed to control the on-surface chemical reaction kinetics and self-assembly. Here, we show that a low-energy electron beam can be used to steer chemical reaction kinetics and induce the growth of molecular phases unattainable by thermal annealing. The electron beam provides a well-controlled means of promoting the elementary reaction step, i.e., deprotonation of carboxyl groups. The reaction rate linearly increases with increasing electron beam energy beyond the threshold energy of 6 eV. Our results offer the novel prospect of controlling the self-assembly, enhancing the rate of reaction steps selectively, and thus altering the kinetic rate hierarchy.

Programmable Dynamic Steady States in ATP-Driven Non-Equilibrium DNA Systems

2019 ◽  
Author(s):  
Laura Heinen ◽  
Andreas Walther
Keyword(s):  
Self Assembly ◽  
Soft Matter ◽  
Enzymatic Reaction ◽  
Reaction Network ◽  
Steady States ◽  
Supramolecular Systems ◽  
Kinetics Of ◽  
Average Bond ◽  
Full Synchronization ◽  
Non Equilibrium

<div><div><div><p>Inspired by the dynamics of the dissipative self-assembly of microtubules, chemically fueled synthetic systems with transient lifetimes are emerging for non-equilibrium materials design. However, realizing programmable or even adaptive structural dynamics has proven challenging because it requires synchronization of energy uptake and dissipation events within true steady states, which remains difficult to orthogonally control in supramolecular systems. Here, we demonstrate full synchronization of both events by ATP-fueled activation and dynamization of covalent DNA bonds via an enzymatic reaction network of concurrent ligation and cleavage. Critically, the average bond ratio and the frequency of bond exchange are imprinted into the energy dissipation kinetics of the network and tunable through its constituents. We introduce temporally and structurally programmable dynamics by polymerization of transient, dynamic covalent DNA polymers with adaptive steady-state properties in dependence of ATP fuel and enzyme concentrations. This approach enables generic access to non-equilibrium soft matter systems with adaptive and programmable dynamics.</p></div></div></div>

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