Biocompatibility of Cyclopropylamine-Based Plasma Polymers Deposited at Sub-Atmospheric Pressure on Poly (ε-caprolactone) Nanofiber Meshes

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.

The role of plasma-induced surface chemistry on polycaprolactone nanofibers to direct chondrogenic differentiation of human mesenchymal stem cells

Bone marrow-derived mesenchymal stromal cells (BMSCs) are extensively being utilized for cartilage regeneration owing to their excellent differentiation potential and availability. However, controlled differentiation of BMSCs towards cartilaginous phenotypes to heal full-thickness cartilage defects remains challenging. This study investigates how different surface properties induced by either coating deposition or biomolecules immobilization onto nanofibers (NFs) could affect BMSCs chondro-inductive behavior. Accordingly, electrospun poly(ε-caprolactone) (PCL) NFs were exposed to two surface modification strategies based on medium-pressure plasma technology. The first strategy is plasma polymerization, in which cyclopropylamine (CPA) or acrylic acid (AcAc) monomers were plasma polymerized to obtain amine- or carboxylic acid-rich NFs, respectively. The second strategy uses a combination of CPA plasma polymerization and a post-chemical technique to immobilize chondroitin sulfate (CS) onto the NFs. These modifications could affect surface roughness, hydrophilicity, and chemical composition while preserving the NFs' nano-morphology. The results of long-term BMSCs culture in both basic and chondrogenic media proved that the surface modifications modulated BMSCs chondrogenic differentiation. Indeed, the incorporation of polar groups by different modification strategies had a positive impact on the cell proliferation rate, production of the glycosaminoglycan matrix, and expression of extracellular matrix proteins (collagen I and collagen II). The chondro-inductive behavior of the samples was highly dependent on the nature of the introduced polar functional groups. Among all samples, carboxylic acid-rich NFs promoted chondrogenesis by higher expression of aggrecan, Sox9, and collagen II with downregulation of hypertrophic markers. Hence, this approach showed an intrinsic potential to have a non-hypertrophic chondrogenic cell phenotype.

In vitro assessment of Momordica charantia/Hypericum perforatum oils loaded PCL/Collagen fibers: Novel scaffold for tissue engineering

The research on tissue engineering applications has been progressing to manufacture ideal tissue scaffold biomaterials. In this study, a double-layered electrospun biofiber scaffold biomaterial including Polycaprolactone (PCL)/Collagen (COL) fibrous inner layer and PCL/ Momordica charantia (MC) and Hypericum perforatum (HP) oils fibrous outer layer was developed to manufacture a functional, novel tissue scaffold with the advantageous mechanical and biological properties. The main approach was to combine the natural perspective using medicinal oils with an engineering point of view to fabricate a potential functional scaffold for tissue engineering. Medicinal plants MC and HP are rich in functional oils and incorporation of them in a tissue scaffold will unveil their potential to augment both new tissue formation and wound healing. In this study, a novel double-layered scaffold prototype was fabricated using electrospinning technique with two PCL fiber layers, first is composed of collagen, and second is composed of oils extracted from medicinal plants. Initially, the composition of plant oils was analyzed. Thereafter the biofiber scaffold layers were fabricated and were evaluated in terms of morphology, physicochemistry, thermal and mechanical features, wettability, in vitro bio-degradability. Double-layered scaffold prototype was further analyzed in terms of in vitro biocompatibility and antibacterial effect. The medicinal oils blend provided antioxidant and antibacterial properties to the novel PCL/Oils layer. The results signify that inner PCL/COL layer exhibited advanced biodegradability of 8.5% compared to PCL and enhanced wettability with 11.7° contact angle. Strength of scaffold prototype was 5.98 N/mm2 thanks to the elastic PCL fibrous matrix. The double-layered functional biofiber scaffold enabled 92% viability after 72 h contact with fibroblast cells and furthermore provided feasible attachment sites for the cells. The functional scaffold prototype's noteworthy mechanical, chemical, and biological features enable it to be suggested as a different novel biomaterial with the potential to be utilized in tissue engineering applications.

From Basics to Frontiers: A Comprehensive Review of Plasma-Modified and Plasma-Synthesized Polymer Films

This comprehensive review begins by tracing the historical development and progress of cold plasma technology as an innovative approach to polymer engineering. The study emphasizes the versatility of cold plasma derived from a variety of sources including low-pressure glow discharges (e.g., radiofrequency capacitively coupled plasmas) and atmospheric pressure plasmas (e.g., dielectric barrier devices, piezoelectric plasmas). It critically examines key operational parameters such as reduced electric field, pressure, discharge type, gas type and flow rate, substrate temperature, gap, and how these variables affect the properties of the synthesized or modified polymers. This review also discusses the application of cold plasma in polymer surface modification, underscoring how changes in surface properties (e.g., wettability, adhesion, biocompatibility) can be achieved by controlling various surface processes (etching, roughening, crosslinking, functionalization, crystallinity). A detailed examination of Plasma-Enhanced Chemical Vapor Deposition (PECVD) reveals its efficacy in producing thin polymeric films from an array of precursors. Yasuda's models, Rapid Step-Growth Polymerization (RSGP) and Competitive Ablation Polymerization (CAP), are explained as fundamental mechanisms underpinning plasma-assisted deposition and polymerization processes. Then, the wide array of applications of cold plasma technology is explored, from the biomedical field, where it is used in creating smart drug delivery systems and biodegradable polymer implants, to its role in enhancing the performance of membrane-based filtration systems crucial for water purification, gas separation, and energy production. It investigates the potential for improving the properties of bioplastics and the exciting prospects for developing self-healing materials using this technology.

Plasma and Polymers: Recent Progress and Trends

Plasma-enhanced synthesis and modification of polymers is a field that continues to expand and become increasingly more sophisticated. The highly reactive processing environments afforded by the inherently dynamic nature of plasma media are often superior to ambient or thermal environments, offering substantial advantages over other processing methods. The fluxes of energy and matter toward the surface enable rapid and efficient processing, whereas the charged nature of plasma-generated particles provides a means for their control. The range of materials that can be treated by plasmas is incredibly broad, spanning pure polymers, polymer-metal, polymer-wood, polymer-nanocarbon composites, and others. In this review, we briefly outline some of the recent examples of the state-of-the-art in the plasma-based polymer treatment and functionalization techniques.

State of the art in nonthermal plasma processing for biomedical applications: Can it help fight viral pandemics like COVID-19?

Plasma processing finds widespread biomedical applications, such as the design of biosensors, antibiofouling surfaces, controlled drug delivery systems, and in plasma sterilizers. In the present coronavirus disease (COVID-19) situation, the prospect of applying plasma processes like surface activation, plasma grafting, plasma-enhanced chemical vapor deposition/plasma polymerization, surface etching, plasma immersion ion implantation, crosslinking, and plasma decontamination to provide timely solutions in the form of better antiviral alternatives, practical diagnostic tools, and reusable personal protective equipment is worth exploring. Herein, the role of nonthermal plasmas and their contributions toward healthcare are timely reviewed to engage different communities in assisting healthcare associates and clinicians, not only to combat the current COVID-19 pandemic but also to prevent similar kinds of future outbreaks.

Cold atmospheric plasma as an interface biotechnology for enhancing surgical implants

Cold atmospheric plasma (CAP) has been intensively researched for direct treatment of living cells and tissues. Significant attention is now being given to its indirect applications in plasma medicine. Surgical implant is an exemplary conveyor to deliver the therapeutic effects of plasma to patients. There is a constant drive to enhance the clinical performance of surgical implants, targeting at the implant-tissue interface. As a versatile and potent tool, CAP is capable of ameliorating surgical implants using various strategies of interface biotechnology, such as surface modification, coating deposition, and drug delivery. Understanding the chemical, physical, mechanical, electrical, and pharmacological processes occurring at the implant-tissue interface is crucial to effective application of CAP as an interface biotechnology. This preclinical review focuses on the recent advances in CAP-assisted implant-based therapy for major surgical specialties. The ultimate goal here is to elicit unique opportunities and challenges for translating implant science to plasma medicine.

Behaviour of Vascular Smooth Muscle Cells on Amine Plasma-Coated Materials with Various Chemical Structures and Morphologies

Amine-coated biodegradable materials based on synthetic polymers have a great potential for tissue remodeling and regeneration because of their excellent processability and bioactivity. In the present study, we have investigated the influence of various chemical compositions of amine plasma polymer (PP) coatings and the influence of the substrate morphology, represented by polystyrene culture dishes and polycaprolactone nanofibers (PCL NFs), on the behavior of vascular smooth muscle cells (VSMCs). Although all amine-PP coatings improved the initial adhesion of VSMCs, 7-day long cultivation revealed a clear preference for the coating containing about 15 at.% of nitrogen (CPA-33). The CPA-33 coating demonstrated the ideal combination of good water stability, a sufficient amine group content, and favorable surface wettability and morphology. The nanostructured morphology of amine-PP-coated PCL NFs successfully slowed the proliferation rate of VSMCs, which is essential in preventing restenosis of vascular replacements in vivo. At the same time, CPA-33-coated PCL NFs supported the continuous proliferation of VSMCs during 7-day long cultivation, with no significant increase in cytokine secretion by RAW 264.7 macrophages. The CPA-33 coating deposited on biodegradable PCL NFs therefore seems to be a promising material for manufacturing small-diameter vascular grafts, which are still lacking on the current market.

Efficacy of Plasma-Polymerized Allylamine Coating of Zirconia after Five Years

Plasma-polymerized allylamine (PPAAm) coatings of titanium enhance the cell behavior of osteoblasts. The purpose of the present study was to evaluate a PPAAm nanolayer on zirconia after a storage period of 5 years. Zirconia specimens were directly coated with PPAAm (ZA0) or stored in aseptic packages at room temperature for 5 years (ZA5). Uncoated zirconia specimens (Zmt) and the micro-structured endosseous surface of a zirconia implant (Z14) served as controls. The elemental compositions of the PPAAm coatings were characterized and the viability, spreading and gene expression of human osteoblastic cells (MG-63) were assessed. The presence of amino groups in the PPAAm layer was significantly decreased after 5 years due to oxidation processes. Cell viability after 24 h was significantly higher on uncoated specimens (Zmt) than on all other surfaces. Cell spreading after 20 min was significantly higher for Zmt = ZA0 > ZA5 > Z14, while, after 24 h, spreading also varied significantly between Zmt > ZA0 > ZA5 > Z14. The expression of the mRNA differentiation markers collagen I and osteocalcin was upregulated on untreated surfaces Z14 and Zmt when compared to the PPAAm specimens. Due to the high biocompatibility of zirconia itself, a PPAAm coating may not additionally improve cell behavior.

3D Hierarchical, Nanostructured Chitosan/PLA/HA Scaffolds Doped with TiO2/Au/Pt NPs with Tunable Properties for Guided Bone Tissue Engineering

Bone tissue is the second tissue to be replaced. Annually, over four million surgical treatments are performed. Tissue engineering constitutes an alternative to autologous grafts. Its application requires three-dimensional scaffolds, which mimic human body environment. Bone tissue has a highly organized structure and contains mostly inorganic components. The scaffolds of the latest generation should not only be biocompatible but also promote osteoconduction. Poly (lactic acid) nanofibers are commonly used for this purpose; however, they lack bioactivity and do not provide good cell adhesion. Chitosan is a commonly used biopolymer which positively affects osteoblasts' behavior. The aim of this article was to prepare novel hybrid 3D scaffolds containing nanohydroxyapatite capable of cell-response stimulation. The matrixes were successfully obtained by PLA electrospinning and microwave-assisted chitosan crosslinking, followed by doping with three types of metallic nanoparticles (Au, Pt, and TiO2). The products and semi-components were characterized over their physicochemical properties, such as chemical structure, crystallinity, and swelling degree. Nanoparticles' and ready biomaterials' morphologies were investigated by SEM and TEM methods. Finally, the scaffolds were studied over bioactivity on MG-63 and effect on current-stimulated biomineralization. Obtained results confirmed preparation of tunable biomimicking matrixes which may be used as a promising tool for bone-tissue engineering.

Hybrid Bilayer PLA/Chitosan Nanofibrous Scaffolds Doped with ZnO, Fe3O4, and Au Nanoparticles with Bioactive Properties for Skin Tissue Engineering

Burns affect almost half a million of Americans annually. In the case of full-thickness skin injuries, treatment requires a transplant. The development of bioactive materials that promote damaged tissue regeneration constitutes a great alternative to autografts. For this reason, special attention is focused on three-dimensional scaffolds that are non-toxic to skin cells and can mimic the extracellular matrix, which is mainly composed of nanofibrous proteins. Electrospinning, which enables the preparation of nanofibers, is a powerful tool in the field of biomaterials. In this work, novel hybrid poly (lactic acid)/chitosan biomaterials functionalized with three types of nanoparticles (NPs) were successfully developed. ZnO, Fe3O4, and Au NPs were investigated over their morphology by TEM method. The top layer was obtained from PLA nanofibers, while the bottom layer was prepared from acylated chitosan. The layers were studied over their morphology by the SEM method and their chemical structure by FT-IR. To verify their potential in burn wound treatment, the scaffolds' susceptibility to biodegradation as well as moisture permeability were calculated. Also, biomaterials conductivity was determined in terms of electrostimulation. Finally, cytotoxicity tests were carried out by XTT assay and morphology analysis using both fibroblasts cell line and primary cells. The hybrid nanofibrous scaffolds displayed a great potential in tissue engineering.