Computer study of the solubilization of polymer chains in polyelectrolyte complex cores of polymeric nanoparticles in aqueous media

2018 ◽  
Vol 20 (47) ◽  
pp. 29876-29888 ◽  
Author(s):  
Karel Šindelka ◽  
Zuzana Limpouchová ◽  
Karel Procházka
Keyword(s):  
Computer Simulations ◽  
Polyelectrolyte Complex ◽  
Polymeric Nanoparticles ◽  
Aqueous Media ◽  
Polymer Chains ◽  
Coarse Grained ◽  
Computer Study ◽  
Interpolyelectrolyte Complex ◽  
Structure Of Nanoparticles ◽  
Polar Polymer

The formation and structure of nanoparticles containing non-polar polymer chains solubilized in interpolyelectrolyte complex (IPC) cores and the partitioning of non-polar chains between bulk solvent and IPC cores were studied by coarse-grained computer simulations.

scholarly journals Solubilization of Charged Porphyrins in Interpolyelectrolyte Complexes: A Computer Study

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 502
Author(s):  
Karel Šindelka ◽  
Zuzana Limpouchová ◽  
Karel Procházka
Keyword(s):  
Dissipative Particle Dynamics ◽  
Water Soluble ◽  
Coarse Grained ◽  
Core Shell ◽  
Computer Study ◽  
Interpolyelectrolyte Complex ◽  
The Core ◽  
Porphyrin Derivatives ◽  
Oppositely Charged ◽  
Positively Charged

Using coarse-grained dissipative particle dynamics (DPD) with explicit electrostatics, we performed (i) an extensive series of simulations of the electrostatic co-assembly of asymmetric oppositely charged copolymers composed of one (either positively or negatively charged) polyelectrolyte (PE) block A and one water-soluble block B and (ii) studied the solubilization of positively charged porphyrin derivatives (P+) in the interpolyelectrolyte complex (IPEC) cores of co-assembled nanoparticles. We studied the stoichiometric mixtures of 137 A10+B25 and 137 A10−B25 chains with moderately hydrophobic A blocks (DPD interaction parameter aAS=35) and hydrophilic B blocks (aBS=25) with 10 to 120 P+ added (aPS=39). The P+ interactions with other components were set to match literature information on their limited solubility and aggregation behavior. The study shows that the moderately soluble P+ molecules easily solubilize in IPEC cores, where they partly replace PE+ and electrostatically crosslink PE− blocks. As the large P+ rings are apt to aggregate, P+ molecules aggregate in IPEC cores. The aggregation, which starts at very low loadings, is promoted by increasing the number of P+ in the mixture. The positively charged copolymers repelled from the central part of IPEC core partially concentrate at the core-shell interface and partially escape into bulk solvent depending on the amount of P+ in the mixture and on their association number, AS. If AS is lower than the ensemble average ⟨AS⟩n, the copolymer chains released from IPEC preferentially concentrate at the core-shell interface, thus increasing AS, which approaches ⟨AS⟩n. If AS>⟨AS⟩n, they escape into the bulk solvent.

scholarly journals Advances in the Multi-Orthogonal Folding of Single Polymer Chains into Single-Chain Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 293
Author(s):  
Agustín Blazquez-Martín ◽  
Ester Verde-Sesto ◽  
Angel J. Moreno ◽  
Arantxa Arbe ◽  
Juan Colmenero ◽  
...  
Keyword(s):  
Computer Simulations ◽  
Chemical Species ◽  
Synthetic Polymers ◽  
Review Article ◽  
Polymer Chains ◽  
Single Chain ◽  
High Dilution ◽  
Covalent Bonds ◽  
Covalent Interactions ◽  
Individual Polymer

The folding of certain proteins (e.g., enzymes) into perfectly defined 3D conformations via multi-orthogonal interactions is critical to their function. Concerning synthetic polymers chains, the “folding” of individual polymer chains at high dilution via intra-chain interactions leads to so-called single-chain nanoparticles (SCNPs). This review article describes the advances carried out in recent years in the folding of single polymer chains into discrete SCNPs via multi-orthogonal interactions using different reactive chemical species where intra-chain bonding only occurs between groups of the same species. First, we summarize results from computer simulations of multi-orthogonally folded SCNPs. Next, we comprehensively review multi-orthogonally folded SCNPs synthesized via either non-covalent bonds or covalent interactions. Finally, we conclude by summarizing recent research about multi-orthogonally folded SCNPs prepared through both reversible (dynamic) and permanent bonds.

Current phthalocyanines delivery systems in photodynamic therapy: an updated review

2021 ◽  
Vol 28 ◽  
Author(s):  
Mariana Miretti ◽  
Cesar German Prucca ◽  
Tomas Cristian Tempesti ◽  
Maria Teresa Baumgartner
Keyword(s):  
Photodynamic Therapy ◽  
Polymeric Micelles ◽  
Polymeric Nanoparticles ◽  
Aqueous Media ◽  
Delivery Systems ◽  
Current Status ◽  
Oxygen Species ◽  
Cancer Treatments ◽  
Therapy Efficacy ◽  
Cellular Components

: Photodynamic therapy has emerged as an effective therapeutic alternative to treat oncological, cardiovascular, dermatological, infectious, and ophthalmic diseases. Photodynamic therapy combines the action of a photosensitizer with light in the presence of oxygen to generate reactive oxygen species capable of reacting with cellular components resulting in injury and, consequently, inducing cellular death. Phthalocyanines are considered good photosensitizers, although most of them are lipophilic, difficulting their administration for clinical use. A strategy to overcome the lack of solubility of phthalocyanines in aqueous media is to incorporate them into different delivery systems. The present review aimed to summarize the current status of the main drug delivery systems used for Zn and Al phthalocyanines and their effect in photodynamic therapy, reported in the last five years. Liposomes, polymeric micelles, polymeric nanoparticles, and gold-nanoparticles constituted some of the most used carriers and were discussed in this review. The latest studies reported strongly suggests that the application of nanotechnologies as delivery systems allow an increase in photodynamic therapy efficacy and reduce side-effects associated with the phthalocyanine administration, which represents a promise for cancer treatments.

scholarly journals Efficient encapsulation of proteins with random copolymers

2018 ◽  
Vol 115 (26) ◽  
pp. 6578-6583 ◽  
Author(s):  
Trung Dac Nguyen ◽  
Baofu Qiao ◽  
Monica Olvera de la Cruz
Keyword(s):  
Enzymatic Activity ◽  
Average Distance ◽  
Aqueous Media ◽  
Adsorbed Layer ◽  
Computational Design ◽  
Polymer Chains ◽  
Disordered Proteins ◽  
Random Copolymers ◽  
Adsorption Sites

Membraneless organelles are aggregates of disordered proteins that form spontaneously to promote specific cellular functions in vivo. The possibility of synthesizing membraneless organelles out of cells will therefore enable fabrication of protein-based materials with functions inherent to biological matter. Since random copolymers contain various compositions and sequences of solvophobic and solvophilic groups, they are expected to function in nonbiological media similarly to a set of disordered proteins in membraneless organelles. Interestingly, the internal environment of these organelles has been noted to behave more like an organic solvent than like water. Therefore, an adsorbed layer of random copolymers that mimics the function of disordered proteins could, in principle, protect and enhance the proteins’ enzymatic activity even in organic solvents, which are ideal when the products and/or the reactants have limited solubility in aqueous media. Here, we demonstrate via multiscale simulations that random copolymers efficiently incorporate proteins into different solvents with the potential to optimize their enzymatic activity. We investigate the key factors that govern the ability of random copolymers to encapsulate proteins, including the adsorption energy, copolymer average composition, and solvent selectivity. The adsorbed polymer chains have remarkably similar sequences, indicating that the proteins are able to select certain sequences that best reduce their exposure to the solvent. We also find that the protein surface coverage decreases when the fluctuation in the average distance between the protein adsorption sites increases. The results herein set the stage for computational design of random copolymers for stabilizing and delivering proteins across multiple media.

scholarly journals Towards the realistic computer model of precipitation polymerization microgels

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vladimir Yu. Rudyak ◽  
Elena Yu. Kozhunova ◽  
Alexander V. Chertovich
Keyword(s):  
Computer Simulations ◽  
Precipitation Polymerization ◽  
Coarse Grained ◽  
Polymerization Process ◽  
New Horizons ◽  
Experimental Systems ◽  
Structure Factors ◽  
The Subject ◽  
First Time

Abstract In this paper we propose a new method of coarse-grained computer simulations of the microgel formation in course of free radical precipitation polymerization. For the first time, we simulate the precipitation polymerization process from a dilute solution of initial components to a final microgel particle with coarse grained molecular dynamics, and compare it to the experimental data. We expect that our simulation studies of PNIPA-like microgels will be able to elucidate the subject of nucleation and growth kinetics and to describe in detail the network topology and structure. Performed computer simulations help to determine the characteristic phases of the growth process and show the necessity of prolongated synthesis for the formation of stable microgel particles. We demonstrate the important role of dangling ends in microgels, which occupy as much as 50% of its molecular mass and have previously unattended influence on the swelling behavior. The verification of the model is made by the comparison of collapse curves and structure factors between simulated and experimental systems, and high quality matching is achieved. This work could help to open new horizons in studies that require the knowledge of detailed and realistic structures of the microgel networks.

A Finite Element-Based Coarse-Grained Model for Cell–Nanomaterial Interactions by Combining Absolute Nodal Coordinate Formula and Brownian Dynamics

2020 ◽  
Vol 88 (4) ◽  
Author(s):  
Teng Ma ◽  
Yuanpeng Liu ◽  
Guochang Lin ◽  
Changguo Wang ◽  
Huifeng Tan
Keyword(s):  
Finite Element ◽  
Brownian Dynamics ◽  
Lipid Membrane ◽  
Contact Region ◽  
Detection Algorithm ◽  
Polymer Chains ◽  
Coarse Grained ◽  
Absolute Nodal Coordinate ◽  
Coarse Grained Model ◽  
Dynamics Simulations

Abstract A fundamental understanding of the interactions between one-dimensional nanomaterials and the cell membrane is of great importance for assessing the hazardous effects of viruses and improving the performance of drug delivery. Here, we propose a finite element-based coarse-grained model to describe the cell entry of nanomaterials based on an absolute nodal coordinate formula and Brownian dynamics. The interactions between nanoparticles and lipid membrane are described by the Lennard–Jones potential, and a contact detection algorithm is used to determine the contact region. Compared with the theoretical and published experimental results, the correctness of the model has been verified. We take two examples to test the robustness of the model: the endocytosis of nanorods grafted with polymer chains and simultaneous entry of multiple nanorods into a lipid membrane. It shows that the model can not only capture the effect of ligand–receptor binding on the penetration but also accurately characterize the cooperative or separate entry of multiple nanorods. This coarse-grained model is computationally highly efficient and will be powerful in combination with molecular dynamics simulations to provide an understanding of cell–nanomaterial interactions.

scholarly journals Onion Micelles with an Interpolyelectrolyte Complex Middle Layer: Experimental Motivation and Computer Study

2020 ◽  
Vol 53 (16) ◽  
pp. 6780-6795
Author(s):  
Rahul Kumar Raya ◽  
Miroslav Štěpánek ◽  
Zuzana Limpouchová ◽  
Karel Procházka ◽  
Martin Svoboda ◽  
...  
Keyword(s):  
Middle Layer ◽  
Computer Study ◽  
Interpolyelectrolyte Complex

scholarly journals The Longitudinal Superdiffusive Motion of Block Copolymer in a Tight Nanopore

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2931
Author(s):  
Waldemar Nowicki
Keyword(s):  
Dynamic Properties ◽  
Polymer Chains ◽  
Coarse Grained ◽  
Free Energy Barrier ◽  
Ballistic Motion ◽  
The Monte Carlo Method ◽  
Long Time ◽  
The Mean ◽  
Confined Environment ◽  
Unidirectional Motion

The structure and dynamic properties of polymer chains in a confined environment were studied by means of the Monte Carlo method. The studied chains were represented by coarse-grained models and embedded into a simple 3D cubic lattice. The chains stood for two-block linear copolymers of different energy of bead–bead interactions. Their behavior was studied in a nanotube formed by four impenetrable surfaces. The long-time unidirectional motion of the chain in the tight nanopore was found to be correlated with the orientation of both parts of the copolymer along the length of the nanopore. A possible mechanism of the anomalous diffusion was proposed on the basis of thermodynamics of the system, more precisely on the free energy barrier of the swapping of positions of both parts of the chain and the impulse of temporary forces induced by variation of the chain conformation. The mean bead and the mass center autocorrelation functions were examined. While the former function behaves classically, the latter indicates the period of time of superdiffusive motion similar to the ballistic motion with the autocorrelation function scaling with the exponent t5/3. A distribution of periods of time of chain diffusion between swapping events was found and discussed. The influence of the nanotube width and the chain length on the polymer diffusivity was studied.

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