Graphene-augmented nanofiber scaffolds demonstrate new features in cells behaviour

Highly fluorescent hybrid nanofibers as potential nanofibrous scaffolds for studying cell-fiber interactions

In this study, we report on the fabrication of hybrid nanofibers for labeling and bioimaging applications. Our approach is involved for developing highly fluorescent nanofibers using a blend of polylactic acid, polyethyleneglycol, and perylenediimide dyes, through the solution blow spinning technique. The nanofibers are exhibited diameters ranging from 330 nm to 420 nm. Nanofibers showed excellent red and near-infrared fluorescence emissive properties in fluorescent spectroscopy. Moreover, the strong two-photon absorption phenomenon was observed for nanofibers under confocal microscopy. To assess the applicability of these fluorescent nanofibers in bioimaging settings, we employ two types of mammalian cells B16F1 melanoma cells and J774.A1 macrophages. Both cell types exhibit negligible cytotoxicity after 24 h incubation with the nanofibers, indicating the suitability of nanofibers for cell-based experiments. We also observe strong interactions between the nanofibers and cells, as evidenced by two major events: a) the acquisition of an elongated cellular morphology with the major cellular axis parallel to the nanofibers and b) the accumulation of actin filaments along the points of contact of the cells with the fibers. Our findings demonstrate the suitability of these newly developed fluorescent nanofibers in cell-based applications for guiding cellular behavior. We expect that these fluorescent nanofibers have the potential to serve as scaffold materials for long-time tracking of cell-fiber interactions in fluorescence microscopy.

A scoping review of graphene-based biomaterials for in vivo bone tissue engineering

The growing demand for more efficient materials for medical applications brought together two previously distinct fields: medicine and engineering. Regenerative medicine has evolved with the engineering contributions to improve materials and devices for medical use. In this regard, graphene is one of the most promising materials for bone tissue engineering and its potential for bone repair has been studied by several research groups. The aim of this study is to conduct a scoping review including articles published in the last 12 years (from 2010 to 2022) that have used graphene and its derivatives (graphene oxide and reduced graphene) in preclinical studies for bone tissue regeneration, searching in PubMed/MEDLINE, Embase, Web of Science, Cochrane Central, and clinicaltrials.gov (to confirm no study has started with clinical trial). Boolean searches were performed using the defined key words "bone" and "graphene", and manuscript abstracts were uploaded to Rayyan, a web-tool for systematic and scoping reviews. This scoping review was conducted based on Joanna Briggs Institute Manual for Scoping Reviews and the report follows the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - Extension for Scoping Reviews (PRISMA-ScR) statement. After the search protocol and application of the inclusion criteria, 77 studies were selected and evaluated by five blinded researchers. Most of the selected studies used composite materials associated with graphene and its derivatives to natural and synthetic polymers, bioglass, and others. Although a variety of graphene materials were analyzed in these studies, they all concluded that graphene, its derivatives, and its composites improve bone repair processes by increasing osteoconductivity, osteoinductivity, new bone formation, and angiogenesis. Thus, this systematic review opens up new opportunities for the development of novel strategies for bone tissue engineering with graphene.

A systematic study of nano-based fibrous systems: Diagnostic and therapeutic approaches for dementia control

Nano-based systems provide many advantages, including eluding gastrointestinal and first-pass metabolism of the drug and improving the potential advantage of reduced doses of drugs for an equal or better therapeutic effect compared to other parts of oral administration. Over the last few years, protein-based nanofibrous biomaterials have been used for better controlling dementia. PubMed, Scopus, and ISI Web of Science were consulted for available articles on nano-based fibrous systems for the treatment and diagnosis of dementia (up to October 2022). Of 725 articles that were identified and evaluated, only 19 were included. Eleven studies evaluated nanofibrous electrospun biomaterials for better dementia control. Among these, four investigated marker/biomarker detection for the early diagnosis of dementia. Two from four studies conducted hydrogel-based nanofibrous for Alzheimer's disease (AD) treatment. Additionally, four studies inspected stem cell (SC) transplantation on nano-based fibrous scaffolds for better treatment of dementia. Finally, two from the final four studies considered nano-based fibrous systems for the enhanced treatment of dementia. Our study concluded that nano-based fibrous platforms, exclusively peptide/protein-based nanofibrous scaffolds made from biomaterials, can be applied for dementia management by either diagnostic or therapeutic approaches specific in purpose-designed electrospun nanofibrous scaffolds.

Updates in immunocompatibility of biomaterials: applications for regenerative medicine

INTRODUCTION

Biomaterials, either metallic, ceramic, or polymeric, can be used in medicine as a part of the implants, dialysis membranes, bone scaffolds, or components of artificial organs. Polymeric biomaterials cover a vast range of biomedical applications. The biocompatibility and immunocompatibility of polymeric materials are of fundamental importance for their possible therapeutic uses, as the immune system can intervene in the materials' performance. Therefore, based on application, different routes can be utilized for immunoregulation.

AREAS COVERED

As different biomaterials can be modulated by different strategies, this study aims to summarize and evaluate the available methods for the immunocompatibility enhancement of more common polymeric biomaterials based on their nature. Different strategies such as surface modification, physical characterization, and drug incorporation are investigated for the immunomodulation of nanoparticles, hydrogels, sponges, and nanofibers.

EXPERT OPINION

Recently, strategies for triggering appropriate immune responses by functional biomaterials have been highlighted. As most strategies correspond to the physical and surface properties of biomaterials, specific modulation can be conducted for each biomaterial system. Besides, different applications require different modulations of the immune system. In the future, the selection of novel materials and immune regulators can play a role in tuning the immune system for regenerative medicine.

Biomechanical and functional comparison of moulded and 3D printed medical silicones

Modern 3D printing of implantable devices provides an important opportunity for the development of personalized implants with good anatomical fit. Nevertheless, 3D printing of silicone has been challenging and the recent advances in technology are provided by the systems which can print medical grade silicone via extrusion. However, the potential impacts of the 3D printing process of silicone on its biomechanical properties has not been studied in sufficient detail. Therefore, the present study compares 3D printed and moulded silicone structures for their cytotoxicity, surface roughness, biomechanical properties, and in vivo tissue reaction. The 3D printing process creates increased nanoscale roughness and noticeably changes microscale topography. Neither the presence of these features nor the differences in processes were found to result in an increase in cytotoxicity or tissue reaction for 3D printed structures, exhibiting limited inflammatory reaction and cell viability above the threshold values. On the contrary, the biomechanical properties have demonstrated significant differences in static and dynamic conditions, and in thermal expansion. Our results demonstrate that 3D printing can be used for establishing a better biomechanical microenvironment for the surrounding tissue of the implant particularly for fragile soft tissue like epithelial mucosa without having any negative effect on the cytotoxicity or in vivo reaction to silicone. For engineering of the implants, however, one must consider the differences in mechanical properties to result in correct and personalized geometry and proper physical interaction with tissues.

Biomechanical Features of Graphene-Augmented Inorganic Nanofibrous Scaffolds and Their Physical Interaction with Viruses

Nanofibrous substrates and scaffolds are widely being studied as matrices for 3D cell cultures, and disease models as well as for analytics and diagnostic purposes. These scaffolds usually comprise randomly oriented fibers. Much less common are nanofibrous scaffolds made of stiff inorganic materials such as alumina. Well-aligned matrices are a promising tool for evaluation of behavior of biological objects affected by micro/nano-topologies as well as anisotropy. In this work, for the first time, we report a joint analysis of biomechanical properties of new ultra-anisotropic, self-aligned ceramic nanofibers augmented with two modifications of graphene shells (GAIN scaffolds) and their interaction of three different viral types (influenza virus A, picornavirus (human parechovirus) and potato virus). It was discovered that nano-topology and structure of the graphene layers have a significant implication on mechanical properties of GAIN scaffolds resulting in non-linear behavior. It was demonstrated that the viral adhesion to GAIN scaffolds is likely to be guided by physical cues in dependence on mutual steric factors, as the scaffolds lack common cell membrane proteins and receptors which viruses usually deploy for transfection. The study may have implications for selective viral adsorption, infected cells analysis, and potentially opening new tools for anti-viral drugs development.

Graphene-based 3D scaffolds in tissue engineering: fabrication, applications, and future scope in liver tissue engineering

Tissue engineering embraces the potential of recreating and replacing defective body parts by advancements in the medical field. Being a biocompatible nanomaterial with outstanding physical, chemical, optical, and biological properties, graphene-based materials were successfully employed in creating the perfect scaffold for a range of organs, starting from the skin through to the brain. Investigations on 2D and 3D tissue culture scaffolds incorporated with graphene or its derivatives have revealed the capability of this carbon material in mimicking in vivo environment. The porous morphology, great surface area, selective permeability of gases, excellent mechanical strength, good thermal and electrical conductivity, good optical properties, and biodegradability enable graphene materials to be the best component for scaffold engineering. Along with the apt microenvironment, this material was found to be efficient in differentiating stem cells into specific cell types. Furthermore, the scope of graphene nanomaterials in liver tissue engineering as a promising biomaterial is also discussed. This review critically looks into the unlimited potential of graphene-based nanomaterials in future tissue engineering and regenerative therapy.

The effects of graphene and mesenchymal stem cells in cutaneous wound healing and their putative action mechanism

This study provides a review of the therapeutic potential of graphene dressing scaffolds and mesenchymal stem cells (MSCs) and their synergistic effects with respect to cutaneous wound healing. This study also considers their putative action mechanism based on the antibacterial, immunomodulating, angiogenic, matrix remodeling effects of materials belonging to the graphene family and MSCs during the wound healing process. In addition, this study discusses the cytocompatibility of graphene, its uses as a platform for skin substitutes, the properties it possesses with respect to providing protection against microbial invasion as well as strategies aimed at minimizing the chance of the occurrence of sepsis. MSCs are capable of secreting several factors that exert a therapeutic impact on reparative processes and tissue regeneration. In light of experiments conducted to date, graphene combined with MSCs appears to have the potential to enhance both the wound healing process and infection control at the injury site.

Hybrid graphene-ceramic nanofibre network for spontaneous neural differentiation of stem cells

A challenge in regenerative medicine is governed by the need to have control over the fate of stem cells that is regulated by the physical and chemical microenvironment in vitro and in vivo. The differentiation of the stem cells into specific lineages is commonly guided by use of specific culture media. For the first time, we demonstrate that human mesenchymal stem cells are capable of turning spontaneously towards neurogenic lineage when seeded on graphene-augmented, highly anisotropic ceramic nanofibres without special differentiation media, contrary to commonly thought requirement of 'soft' substrates for the same purpose. Furthermore, pro-inflammatory gene expression is simultaneously suppressed, and expression of factors promoting focal adhesion and monocytes taxis is upregulated. This opens new possibilities of using local topo-mechanical cues of the 'graphenized' scaffold surfaces to guide stem cell proliferation and differentiation, which can be used in studies of neurological diseases and cell therapy.

Graphene-Augmented Nanofiber Scaffolds Trigger Gene Expression Switching of Four Cancer Cell Types

Three-dimensional (3D) customized scaffolds are anticipated to provide new frontiers in cell manipulation and advanced therapy methods. Here, we demonstrate the application of hybrid 3D porous scaffolds, representing networks of highly aligned self-assembled ceramic nanofibers, for culturing four types of cancer cells. Ultrahigh aspect ratio (∼10⁷) of graphene augmented fibers of tailored nanotopology is shown as an alternative tool to substantially affect cancerous gene expression, eventually due to differences in local biomechanical features of the cell–matrix interactions. Here, we report a clear selective up- and down-regulation of groups of markers for breast cancer (MDA-MB231), colorectal cancer (CaCO2), melanoma (WM239A), and neuroblastoma (Kelly) depending on only fiber orientation and morphology without application of any other stimulus. Changes in gene expression are also revealed for Mitomycin C treatment of MDA-MB231, making the scaffold a suitable platform for testing of anticancer agents. This allows an opportunity for selective “clean” guidance to a deep understanding of mechanisms of cancer cells progressive growth and tumor formation without possible side effects by manipulation with the specific markers.

N+ implantation induce cytocompatibility of shape-controlled three-dimensional self-assembly graphene

AIM

The aim of the present research was to synthesize N⁺ implanted 3D self-assembly graphene (N⁺/3D-SGHs) to overcome the weaknesses of graphene (small sizes and poor hydrophilicity) in tissue engineering scaffolds.

MATERIALS & METHODS

N⁺/3D-SGHs was achieved by ion implantation on one-step hydrothermal synthesized 3D self-assembly graphene (3D-SGHs), and N⁺/3D-SGHs with different doses of nitrogen ions (1 × 10¹⁶ ions/cm², 1 × 10¹⁸ ions/cm² and 1 × 10²⁰ ions/cm²), which adjusted by nitrogen ion beam intensity.

RESULTS

N⁺/3D-SGHs, as scaffolds, provide stereo space and hydrophilic groups for mouse-fibroblast cells (L929) growth and proliferation. Notably, N⁺/3D-SGHs with the N⁺ injected quantity of 1 × 10²⁰ ions/cm² displayed the highest protein-adhesion strength, cell viability and proliferation, which supported its good cytocompatibility.

CONCLUSION

This study demonstrated N⁺/3D-SGHs as a promising and effective tissue scaffold that might have applications in biomedicine.