Nonthermal plasma processing for nanostructured biomaterials and tissue engineering scaffolds: A mini review

Influence of Alkanolamine Plasmas on Poly(Ethylene Terephthalate) Fibro-Porous Biomaterial Constructs

The development of fibrous polymer scaffolds is highly valuable for applications in tissue engineering. Furthermore, there is an extensive body of literature for chemical methods to produce scaffolds that release nitric oxide. However, these methods often use harsh chemistries and leave behind bulk waste. Alkanolamine low-temperature plasma (LTP) is unexplored and single-step processing to form nitric oxide (NO) releasing constructs is highly desirable. The major question addressed is whether it is possible to achieve single-step processing of spun polyester with alkanolamine plasma to achieve nitric oxide releasing capabilities. Herein we report the experiments, processes, and data that support the claim that it is indeed possible to produce such a bio-functional material for potential biomedical applications, especially in cardiovascular implants. Among the tested alkanolamines, monoethylamine (MEA) plasma treated biomaterial outperformed in comparison with diethanolamine (DEA) and triethanolamine (TEA) in terms of NO release and cellular response.

Cold Plasma Technology Based Eco-Friendly Food Packaging Biomaterials

Biopolymers have intrinsic drawbacks compared to traditional plastics, such as hydrophilicity, poor thermo-mechanical behaviours, and barrier characteristics. Therefore, biopolymers or their film modifications offer a chance to create packaging materials with specified properties. Cold atmospheric plasma (CAP) or Low temperature plasma (LTP) has a wide range of applications and has recently been used in the food industry as a potent tool for non-thermal food processing. Though its original purpose was to boost polymer surface energy for better adherence and printability, it has since become an effective technique for surface decontamination of food items and food packaging materials. These revolutionary innovative food processing methods enable the balance between the economic constraints and higher quality while ensuring food stability and minimal processing. For CAP to be considered as a viable alternative food processing technology, it must positively affect food quality. Food products may have their desired functional qualities by adjusting the conditions for cold plasma formation. Cold plasma is a non-thermal method that has little effects on the treated materials and is safe for the environment. In this review, we focus on recent cold plasma advances on various food matrices derived from plants and animals with the aim of highlighting potential applications, ongoing research, and market trends.

Low-Temperature Plasma Techniques in Biomedical Applications and Therapeutics: An Overview

Plasma, the fourth fundamental state of matter, comprises charged species and electrons, and it is a fascinating medium that is spread over the entire visible universe. In addition to that, plasma can be generated artificially under appropriate laboratory techniques. Artificially generated thermal or hot plasma has applications in heavy and electronic industries; however, the non-thermal (cold atmospheric or low temperature) plasma finds its applications mainly in biomedicals and therapeutics. One of the important characteristics of LTP is that the constituent particles in the plasma stream can often maintain an overall temperature of nearly room temperature, even though the thermal parameters of the free electrons go up to 1 to 10 keV. The presence of reactive chemical species at ambient temperature and atmospheric pressure makes LTP a bio-tolerant tool in biomedical applications with many advantages over conventional techniques. This review presents some of the important biomedical applications of cold-atmospheric plasma (CAP) or low-temperature plasma (LTP) in modern medicine, showcasing its effect in antimicrobial therapy, cancer treatment, drug/gene delivery, tissue engineering, implant modifications, interaction with biomolecules, etc., and overviews some present challenges in the field of plasma medicine.

Plasma Surface Engineering of Natural and Sustainable Polymeric Derivatives and Their Potential Applications

Recently, natural as well as synthetic polymers have been receiving significant attention as candidates to replace non-renewable materials. With the exponential developments in the world each day, the collateral damage to the environment is incessant. Increased demands for reducing pollution and energy consumption are the driving force behind the research related to surface-modified natural fibers (NFs), polymers, and various derivatives of them such as natural-fiber-reinforced polymer composites. Natural fibers have received special attention for industrial applications due to their favorable characteristics, such as low cost, abundance, light weight, and biodegradable nature. Even though NFs offer many potential applications, they still face some challenges in terms of durability, strength, and processing. Many of these have been addressed by various surface modification methodologies and compositing with polymers. Among different surface treatment strategies, low-temperature plasma (LTP) surface treatment has recently received special attention for tailoring surface properties of different materials, including NFs and synthetic polymers, without affecting any of the bulk properties of these materials. Hence, it is very important to get an overview of the latest developments in this field. The present article attempts to give an overview of different materials such as NFs, synthetic polymers, and composites. Special attention was placed on the low-temperature plasma-based surface engineering of these materials for diverse applications, which include but are not limited to environmental remediation, packaging, biomedical devices, and sensor development.

Nanoporous Stainless Steel Materials for Body Implants-Review of Synthesizing Procedures

Despite the inadequate biocompatibility, medical-grade stainless steel materials have been used as body implants for decades. The desired biological response of surfaces to specific applications in the body is a highly challenging task, and usually not all the requirements of a biomaterial can be achieved. In recent years, nanostructured surfaces have shown intriguing results as cell selectivity can be achieved by specific surface nanofeatures. Nanoporous structures can be fabricated by anodic oxidation, which has been widely studied for titanium and its alloys, while no systematic studies are so far available for stainless steel (SS) materials. This paper reviews the current state of the art in the anodisation of SS; correlations between the parameters of anodic oxidation and the surface morphology are drawn. The results reported by various authors are scattered because of a variety of experimental configurations. A linear correlation between the pores' diameter anodisation voltage was deduced, while no correlation with other processing parameters was found obvious. The analyses of available data indicated a lack of systematic experiments, which are recommended to understand the kinetics of pore formation and develop techniques for optimal biocompatibility of stainless steel.

Electrospun Fibers Derived from Peptide Coupled Amphiphilic Copolymers for Dorsal Root Ganglion (DRG) Outgrowth

Developing scaffolds with appropriate mechanical/structural features as well as tunable bioactivities are indispensable in the field of tissue engineering. This study focused on one such attempt to electrospin the copolymer of L-lactic acid (L-LA) and functional monomer (3(S)- [(benzyloxycarbony)methyl]-1,4-dioxane-2,5-dione, BMD) with small peptide modifications for the purpose of neural tissue engineering. Scanning Electron Microscopy (SEM) micrographs showed fabricated electrospun copolymer as porous and uniform nanofibrous materials with diameter in the range of 800-1000 nm. In addition, the modified scaffolds displayed a lower contact angle than poly(L-lactide) (PLLA) indicating higher hydrophilicity. To further incorporate the bioactive functions, the nanofibers were chemically coupled with small peptide (isoleucine-lysine-valine-alanine-valine, IKVAV). The incorporation of IKVAV onto the electrospun fiber was confirmed by X-ray photoelectron spectroscopy (XPS) and such incorporation did not affect the surface morphology or fiber diameters. To demonstrate the potential of applying the designed scaffolds for nerve regeneration, dorsal root ganglion (DRG) neurons were cultured on the nanofibers to examine the impact on neurite outgrowth of DRGs. The results indicated that the fabricated nanofibrous matrix with small peptide might be a potential candidate for neural tissue engineering.