scholarly journals Electroactive Smart Polymers for Biomedical Applications

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 277 ◽  
Author(s):  
Humberto Palza ◽  
Paula Zapata ◽  
Carolina Angulo-Pineda
Keyword(s):  
Tissue Engineering ◽  
Biomedical Applications ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Electrical Current ◽  
Electroactive Polymers ◽  
Electrical Stimulus ◽  
Smart Polymers ◽  
Conductive Composites ◽  
Conductive Hydrogels

The flexibility in polymer properties has allowed the development of a broad range of materials with electroactivity, such as intrinsically conductive conjugated polymers, percolated conductive composites, and ionic conductive hydrogels. These smart electroactive polymers can be designed to respond rationally under an electric stimulus, triggering outstanding properties suitable for biomedical applications. This review presents a general overview of the potential applications of these electroactive smart polymers in the field of tissue engineering and biomaterials. In particular, details about the ability of these electroactive polymers to: (1) stimulate cells in the context of tissue engineering by providing electrical current; (2) mimic muscles by converting electric energy into mechanical energy through an electromechanical response; (3) deliver drugs by changing their internal configuration under an electrical stimulus; and (4) have antimicrobial behavior due to the conduction of electricity, are discussed.

Model-Based Optimization and Characterization of DEAP Multilayer Stack-Actuators

2014 ◽  
Author(s):  
Thorben Hoffstadt ◽  
Jürgen Maas
Keyword(s):  
Mechanical Energy ◽  
Electric Energy ◽  
Electrical Energy ◽  
Electroactive Polymers ◽  
Design Parameters ◽  
Optimal Operating ◽  
Electromechanical Instability ◽  
Electrostatic Pressure ◽  
Multilayer Actuators

Actuators based on dielectric electroactive polymers (DEAP) use the electrostatic pressure to convert electrical into mechanical energy. Stack-actuators are a common approach to realize DEAP-based multilayer actuators. To optimize the stationary generated force and stretch the influences of material and free design parameters are investigated based on a model of a loss-free actuator. For this purpose the stretch-force-behavior depending on the applied electric energy is introduced. Based on this approach, besides the general scalability of the force and stretch, an optimal operating point can be determined at which the ratio of generated mechanical work to the applied electrical energy is maximized. To further consider performance limitations of such actuators the known effect of electromechanical instability is finally investigated depending on the generated force yielding to critical stretches, forces and energies.

Graphene and Graphene-Based Materials in Biomedical Applications

2019 ◽  
Vol 26 (38) ◽  
pp. 6834-6850 ◽  
Author(s):  
Mohammad Omaish Ansari ◽  
Kalamegam Gauthaman ◽  
Abdurahman Essa ◽  
Sidi A. Bencherif ◽  
Adnan Memic
Keyword(s):  
Tissue Engineering ◽  
Thermal Properties ◽  
Gene Delivery ◽  
Regenerative Medicine ◽  
Biomedical Research ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Two Dimensional ◽  
Drug And Gene Delivery ◽  
Biomedical Fields

: Nanobiotechnology has huge potential in the field of regenerative medicine. One of the main drivers has been the development of novel nanomaterials. One developing class of materials is graphene and its derivatives recognized for their novel properties present on the nanoscale. In particular, graphene and graphene-based nanomaterials have been shown to have excellent electrical, mechanical, optical and thermal properties. Due to these unique properties coupled with the ability to tune their biocompatibility, these nanomaterials have been propelled for various applications. Most recently, these two-dimensional nanomaterials have been widely recognized for their utility in biomedical research. In this review, a brief overview of the strategies to synthesize graphene and its derivatives are discussed. Next, the biocompatibility profile of these nanomaterials as a precursor to their biomedical application is reviewed. Finally, recent applications of graphene-based nanomaterials in various biomedical fields including tissue engineering, drug and gene delivery, biosensing and bioimaging as well as other biorelated studies are highlighted.

scholarly journals The effects of cononsolvents on the synthesis of responsive particles via polymerisation-induced thermal self-assembly

2021 ◽  
Author(s):  
Marissa Morales-Moctezuma ◽  
Sebastian G Spain
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Self Assembly ◽  
Biomedical Applications

Nanogels have emerged as innovative platforms for numerous biomedical applications including gene and drug delivery, biosensors, imaging, and tissue engineering. Polymerisation-induced thermal self-assembly (PITSA) has been shown to be suitable...

scholarly journals GAKTpore: Stereological Characterisation Methods for Porous Foams in Biomedical Applications

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1269
Author(s):  
Gareth Sheppard ◽  
Karl Tassenberg ◽  
Bogdan Nenchev ◽  
Joel Strickland ◽  
Ramy Mesalam ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Biomedical Applications ◽  
Large Scale ◽  
Collagen Scaffold ◽  
Porous Structures ◽  
Tissue Engineering Scaffolds ◽  
Biological Responses ◽  
Sem Micrograph ◽  
Cell Adhesion And Proliferation ◽  
Characterisation Methods

In tissue engineering, scaffolds are a key component that possess a highly elaborate pore structure. Careful characterisation of such porous structures enables the prediction of a variety of large-scale biological responses. In this work, a rapid, efficient, and accurate methodology for 2D bulk porous structure analysis is proposed. The algorithm, “GAKTpore”, creates a morphology map allowing quantification and visualisation of spatial feature variation. The software achieves 99.6% and 99.1% mean accuracy for pore diameter and shape factor identification, respectively. There are two main algorithm novelties within this work: (1) feature-dependant homogeneity map; (2) a new waviness function providing insights into the convexity/concavity of pores, important for understanding the influence on cell adhesion and proliferation. The algorithm is applied to foam structures, providing a full characterisation of a 10 mm diameter SEM micrograph (14,784 × 14,915 px) with 190,249 pores in ~9 min and has elucidated new insights into collagen scaffold formation by relating microstructural formation to the bulk formation environment. This novel porosity characterisation algorithm demonstrates its versatility, where accuracy, repeatability, and time are paramount. Thus, GAKTpore offers enormous potential to optimise and enhance scaffolds within tissue engineering.

scholarly journals Hydrodynamic constraints on the energy efficiency of droplet electricity generators

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Antoine Riaud ◽  
Cui Wang ◽  
Jia Zhou ◽  
Wanghuai Xu ◽  
Zuankai Wang
Keyword(s):  
Energy Efficiency ◽  
Kinetic Energy ◽  
Total Energy ◽  
Viscous Dissipation ◽  
Shear Force ◽  
Mechanical Energy ◽  
Electric Energy ◽  
The Past ◽  
Viscous Shear ◽  
Impingement Velocity

AbstractElectric energy generation from falling droplets has seen a hundred-fold rise in efficiency over the past few years. However, even these newest devices can only extract a small portion of the droplet energy. In this paper, we theoretically investigate the contributions of hydrodynamic and electric losses in limiting the efficiency of droplet electricity generators (DEG). We restrict our analysis to cases where the droplet contacts the electrode at maximum spread, which was observed to maximize the DEG efficiency. Herein, the electro-mechanical energy conversion occurs during the recoil that immediately follows droplet impact. We then identify three limits on existing droplet electric generators: (i) the impingement velocity is limited in order to maintain the droplet integrity; (ii) much of droplet mechanical energy is squandered in overcoming viscous shear force with the substrate; (iii) insufficient electrical charge of the substrate. Of all these effects, we found that up to 83% of the total energy available was lost by viscous dissipation during spreading. Minimizing this loss by using cascaded DEG devices to reduce the droplet kinetic energy may increase future devices efficiency beyond 10%.

scholarly journals Oxygen Permeability of Silk Fibroin Hydrogels and Their Use as Materials for Contact Lenses: A Purposeful Analysis

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Traian V. Chirila
Keyword(s):  
Tissue Engineering ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Biomedical Applications ◽  
Oxygen Permeability ◽  
Contact Lenses ◽  
The Past ◽  
Fibrous Protein ◽  
Silk Moth ◽  
Bombyx Mori Silk

Fibroin is a fibrous protein that can be conveniently isolated from the silk cocoons produced by the larvae of Bombyx mori silk moth. In its form as a hydrogel, Bombyx mori silk fibroin (BMSF) has been employed in a variety of biomedical applications. When used as substrates for biomaterial-cells constructs in tissue engineering, the oxygen transport characteristics of the BMSF membranes have proved so far to be adequate. However, over the past three decades the BMSF hydrogels have been proposed episodically as materials for the manufacture of contact lenses, an application that depends on substantially elevated oxygen permeability. This review will show that the literature published on the oxygen permeability of BMSF is both limited and controversial. Additionally, there is no evidence that contact lenses made from BMSF have ever reached commercialization. The existing literature is discussed critically, leading to the conclusion that BMSF hydrogels are unsuitable as materials for contact lenses, while also attempting to explain the scarcity of data regarding the oxygen permeability of BMSF. To the author’s knowledge, this review covers all publications related to the topic.

scholarly journals In silico study of PEI-PEG-squalene-dsDNA polyplex formation: The delicate role of PEG length to the binding of PEI to DNA

2021 ◽  
Author(s):  
Tudor Vasiliu ◽  
Bogdan Florin Florin Craciun ◽  
Andrei Neamtu ◽  
Lilia Clima ◽  
Dragos Lucian Isac ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Polyethylene Glycol ◽  
Gene Delivery ◽  
In Silico ◽  
Biomedical Applications ◽  
Experimental Studies ◽  
Biomedical Devices ◽  
In Silico Study ◽  
Or Gene

The biocompatible hydrophilic polyethylene glycol (PEG) is widely used in biomedical applications, such as drug or gene delivery, tissue engineering or as antifouling in biomedical devices. Experimental studies have shown...

scholarly journals Wet-spinning of magneto-responsive helical chitosan microfibers

2020 ◽  
Vol 11 ◽  
pp. 991-999
Author(s):  
Dorothea Brüggemann ◽  
Johanna Michel ◽  
Naiana Suter ◽  
Matheus Grande de Aguiar ◽  
Michael Maas
Keyword(s):  
Tissue Engineering ◽  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Mechanical Energy ◽  
Accessible Surface Area ◽  
Wet Spinning ◽  
Helical Structures ◽  
Structural Reinforcement ◽  
Electron Microscopy Analysis ◽  
Accessible Surface

Helical structures can be found in nature at various length scales ranging from the molecular level to the macroscale. Due to their ability to store mechanical energy and to optimize the accessible surface area, helical shapes contribute particularly to motion-driven processes and structural reinforcement. Due to these special features, helical fibers have become highly attractive for biotechnological and tissue engineering applications. However, there are only a few methods available for the production of biocompatible helical microfibers. Given that, we present here a simple technique for the fabrication of helical chitosan microfibers with embedded magnetic nanoparticles. Composite fibers were prepared by wet-spinning and coagulation in an ethanol bath. Thereby, no toxic components were introduced into the wet-spun chitosan fibers. After drying, the helical fibers had a diameter of approximately 130 µm. Scanning electron microscopy analysis of wet-spun helices revealed that the magnetic nanoparticles agglomerated into clusters inside the fiber matrix. The helical constructs exhibited a diameter of approximately 500 µm with one to two windings per millimeter. Due to their ferromagnetic properties they are easily attracted to a permanent magnet. The results from the tensile testing show that the helical chitosan microfibers exhibited an average Young’s modulus of 14 MPa. By taking advantage of the magnetic properties of the feedstock solution, the production of the helical fibers could be automated. The fabrication of the helical fibers was achieved by utilizing the magnetic properties of the feedstock solution and winding the emerging fiber around a rotating magnetic collector needle upon coagulation. In summary, our helical chitosan microfibers are very attractive for future use in magnetic tissue engineering or for the development of biocompatible actuator systems.

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