A Molecular Modelling Approach for Designing Bioartificial Membranes for Clinical Use With Tailored Transport Properties

Author(s):  
Mariana Ionita ◽  
Alfonso Gautieri ◽  
Emiliano Votta ◽  
Alberto Redaelli

There has been a demand for hemodialysis membranes with better biocompatibility, the use of which would reduce the incidence of complications in patients who have been under long hemodialysis treatment. Recently, highly biocompatible membranes have been obtained by blending synthetic and polymers [1]. Specifically, poly(vinyl-alcohol) (PVA) and poly(acrylic acid) (PAA) have been combined with chitosan (Chi) and dextran (Dex) to create a biomaterials with excellent biocompatibility and mechanical properties. In this work we present a computational method based on molecular mechanics (MM) and dynamics (MD) techniques have been combined with an experimental studies, with the aim of designing and forecasting the permeability and diffusion properties of these membranes to small molecules, as a function of their composition.

1999 ◽  
Vol 600 ◽  
Author(s):  
S. P. Marra ◽  
K. T. Ramesh ◽  
A. S. Douglas

AbstractActive polymer gels can achieve large, reversible deformations in response to environmental stimuli, such as the application of an electric field or a change in pH level. Consequently, great interest exists in using these gels as actuators and artificial muscles. The goal of this work is to characterize the mechanical properties of ionic polymer gels and to describe how these properties evolve as the gel actuates. Experimental results of uniaxial tests on poly(vinyl alcohol)-poly(acrylic acid) gels are presented for both acidic and basic environments. These materials are shown to be to be slightly viscoelastic and compressible and capable of large recoverable deformations. The gels also exhibit similar stress in response to mechanical deformation in both the acid and the base.


2006 ◽  
Vol 110 (46) ◽  
pp. 23031-23040 ◽  
Author(s):  
Annamaria Tedeschi ◽  
Finizia Auriemma ◽  
Rosa Ricciardi ◽  
Gaetano Mangiapia ◽  
Marco Trifuoggi ◽  
...  

2016 ◽  
Vol 36 (3) ◽  
pp. 186-195 ◽  
Author(s):  
P Subba Rao ◽  
K Renji ◽  
MR Bhat

This paper presents molecular dynamics (MD) simulations on the effects of carbon nanotubes (CNTs) without and with chemical functionalization, on the mechanical properties of bisphenol E cyanate ester (BECy) – a potential structural resin. Atomistic models of CNTs, functionalized CNTs (fCNTs), BECy resin, CNT-BECy and fCNT-BECy resins with definite quantity of CNT/fCNT are built. Using these atomistic models, mechanical properties of the above nanosystems are estimated through a computational method involving geometric optimization and equilibration through MD by judiciously establishing various parameters. Adoptability of the approach taken up in this work to model and solve complex nanosystems capturing interactions in the interfacial region between CNT/fCNT and the resin to understand the mechanical behaviour has been highlighted. These investigations have yielded interesting and encouraging results to arrive at optimum quantity of CNTs/fCNTs to be added to achieve enhanced mechanical properties of BECy resin that validate the previous experimental studies carried out by the authors infusing similar quantities of CNTs and fCNTs into BECy.


2017 ◽  
Vol 5 (10) ◽  
pp. 313-321
Author(s):  
Krisztina Roman ◽  
Gabriella Zsoldos

In this paper, the modification of PVC/Corn cob blends was investigated. Rheological and diffusion properties of blends are important to learn the behavior of blend’s in molten state, because it will provide information necessary for the processing. Nowadays, the development of biomaterials has become a primary goal for material engineers. Using materials from natural sources gives an option to modify PVC structures and properties. The following mechanical properties of the prepared composite were determined; tensile-, bending strength and hardness. The PVC/Corn cob blends have increased impact strength and the other mechanical properties can be improved as well. The relationship between the morphology and properties of the foam were also investigated. The result of DSC and dynamic mechanical analysis showed that the blends form a partially compatible system. The rheological analysis showed that the PVC composite with corn cob could be processed and recycled using regular thermoplastic processing systems.


Author(s):  
Mariana Ionita ◽  
Davide Silvestri ◽  
Alfonso Gautieri ◽  
Emiliano Votta ◽  
Gianluca Ciardelli ◽  
...  

In order to improve the biological performance of synthetic polymers and to enhance the mechanical characteristics by tailoring the permeability properties of biopolymers, a new class of specifically designed materials (bioartificial polymeric materials), consisting of blends of synthetic polymers and biopolymers, has been recently introduced. In this work we present a computational method based on molecular mechanics (MM) and dynamics (MD) techniques, to investigate their permeability to small molecules. The permeability properties was assessed of poly(vinyl alcohol)-(PVA)- dextran-(Dex) and poly(acrylic acid)-(PAA)-Dex membranes with different blend composition. Amorphous bulk models of PVA–Dex and PAA–Dex mixtures with 80:20, 60:40, 40:60 (w/w) ratios were generated. Two steps have been performed iteratively, the former using a MM simulation for equilibration and the latter using MD simulations for model refinement. Virtual uniaxial traction tests were performed, adopting the Second Derivative (SD) procedure, in order to assess the mechanical behavior of the bulk models. The diffusion coefficients for H2O were determined via NVT molecular dynamics simulations. Using the data of the motion of water inside the bulk models, the diffusivity constant was calculated applying the Einstein equation. Correlation of diffusion coefficients with free volume, was found. The results of the simulations agree with theoretical considerations: as the content of dextran increases from 80:20 to 40:60 a 86 % decrease of the diffusion constant is obtained and the values (range 0.14–56.5 10−6 cm2s−1) have the order of magnitude expected, and similar on the diffusion of small molecules in amorphous polymeric membranes.


2020 ◽  
Vol 44 (25) ◽  
pp. 10390-10403
Author(s):  
Zhanxin Jing ◽  
Xueying Xian ◽  
Qiuhong Huang ◽  
Qiurong Chen ◽  
Pengzhi Hong ◽  
...  

Biocompatible double network PAmAA–Al3+/PVA/GO nanocomposite hydrogels based on non-covalent interactions were synthesized, and the non-covalent interactions endow the materials with good self-recovery and self-healing performances.


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