Bio-electrospraying is a safe technology for delivering human adipose-derived stem cells

Application and Development of Electrospun Nanofiber Scaffolds for Bone Tissue Engineering

Nanofiber scaffolds have gained significant attention in the field of bone tissue engineering. Electrospinning, a straightforward and efficient technique for producing nanofibers, has been extensively researched. When used in bone tissue engineering scaffolds, electrospun nanofibers with suitable surface properties promote new bone tissue growth and enhance cell adhesion. Recent advancements in electrospinning technology have provided innovative approaches for scaffold fabrication in bone tissue engineering. This review comprehensively examines the utilization of electrospun nanofibers in bone tissue engineering scaffolds and evaluates the relevant literature. The review begins by presenting the fundamental principles and methodologies of electrospinning. It then discusses various materials used in the production of electrospun nanofiber scaffolds for bone tissue engineering, including natural and synthetic polymers, as well as certain inorganic materials. The challenges associated with these materials are also described. The review focuses on novel electrospinning techniques for scaffold construction in bone tissue engineering, such as multilayer nanofibers, multifluid electrospinning, and the integration of electrospinning with other methods. Recent advancements in electrospinning technology have enabled the fabrication of precisely aligned nanofiber scaffolds with nanoscale architectures. These innovative methods also facilitate the fabrication of biomimetic structures, wherein bioactive substances can be incorporated and released in a controlled manner for drug delivery purposes. Moreover, they address issues encountered with traditional electrospun nanofibers, such as mechanical characteristics and biocompatibility. Consequently, the development and implementation of novel electrospinning technologies have revolutionized scaffold fabrication for bone tissue engineering.

In Situ Precision Cell Electrospinning as an Efficient Stem Cell Delivery Approach for Cutaneous Wound Healing

Mesenchymal stem cell (MSC) therapies have been brought forward as a promising treatment modality for cutaneous wound healing. However, current approaches for stem cell delivery have many drawbacks, such as lack of targetability and cell loss, leading to poor efficacy of stem cell therapy. To overcome these problems, in the present study, an in situ cell electrospinning system is developed as an attractive approach for stem cell delivery. MSCs have a high cell viability of over 90% even with a high applied voltage of 15 kV post-cell electrospinning process. In addition, cell electrospinning does not show any negative effect on the surface marker expression and differentiation capacity of MSCs. In vivo studies demonstrate that in situ cell electrospinning treatment can promote cutaneous wound healing through direct deposition of bioactive fish gelatin fibers and MSCs onto wound sites, leading to a synergic therapeutic effect. The approach enhances extracellular matrix remodeling by increasing collagen deposition, promotes angiogenesis by increasing the expression of vascular endothelial growth factor (VEGF) and forming small blood vessels, and dramatically reduces the expression of interleukin-6 (IL-6) during wound healing. The use of in situ cell electrospinning system potentially provides a rapid, no touch, personalized treatment for cutaneous wound healing.

Advancements and Future Perspectives in Cell Electrospinning and Bio-Electrospraying

In recent years, researchers have tried to include living cells into electrospun nanofibers or droplets, leading to the field of live cell electrospinning and bio-electrospraying . In live cell electrospinning and bio-electrospraying, cells are embedded in a polymer and subject to the process of mechanical and electrical stimulation of the process. The resulting nanofiber mats or droplets with embedded cells have several potential applications in tissue engineering. The nanofiber structure provides a supportive and porous environment for cells to grow and interact with their surroundings. This can be favorable for tissue regeneration, where the goal is to create functional tissues that closely mimic the extracellular matrix. However, there are also challenges associated with live cell electrospinning and electrospraying, including maintaining cell viability and uniform cell distribution within the nanofiber mat. Additionally, the electrospinning/electrospraying process can have an impact on cell behavior, phenotype, and genotype, which must be cautiously monitored and studied. Overall, the goal of this review paper is to provide a comprehensive and critical analysis of the existing literature on cell electrospinning and bio-electrospraying.

Bio-electrospraying assessment toward in situ chondrocyte-laden electrospun scaffold fabrication

Electrospinning has been widely used to fabricate fibrous scaffolds for cartilage tissue engineering, but their small pores severely restrict cell infiltration, resulting in an uneven distribution of cells across the scaffold, particularly in three-dimensional designs. If bio-electrospraying is applied, direct chondrocyte incorporation into the fibers during electrospinning may be a solution. However, before this approach can be effectively employed, it is critical to identify whether chondrocytes are adversely affected. Several electrospraying operating settings were tested to determine their effect on the survival and function of an immortalized human chondrocyte cell line. These chondrocytes survived through an electric field formed by low needle-to-collector distances and low voltage. No differences in chondrocyte viability, morphology, gene expression, or proliferation were found. Preliminary data of the combination of electrospraying and polymer electrospinning disclosed that chondrocyte integration was feasible using an alternated approach. The overall increase in chondrocyte viability over time indicated that the embedded cells retained their proliferative capacity. Besides the cell line, primary chondrocytes were also electrosprayed under the previously optimized operational conditions, revealing the higher sensitivity degree of these cells. Still, their post-electrosprayed viability remained considerably high. The data reported here further suggest that bio-electrospraying under the optimal operational conditions might be a promising alternative to the existent cell seeding techniques, promoting not only cells safe delivery to the scaffold, but also the development of cellularized cartilage tissue constructs.

Electrospray: More than just an ionization source

Electrospraying (ES) is a potential-driven process of liquid atomization, which is employed in the field of analytical chemistry, particularly as an ionization technique for mass spectrometric analyses of biomolecules. In this review, we demonstrate the extraordinary versatility of the electrospray by overviewing the specifics and advanced applications of ES-based processing of low molecular mass compounds, biomolecules, polymers, nanoparticles, and cells. Thus, under suitable experimental conditions, ES can be used as a powerful tool for highly controlled deposition of homogeneous films or various patterns, which may sometimes even be organized into 3D structures. We also emphasize its capacity to produce composite materials including encapsulation systems and polymeric fibers. Further, we present several other, less common ES-based applications. This review provides an insight into the remarkable potential of ES, which can be very useful in the designing of innovative and unique strategies.

Bio-electrosprayed human neural stem cells are viable and maintain their differentiation potential

Background: Bio-electrospray (BES) is a jet-based delivery system driven by an electric field that has the ability to form micro to nano-sized droplets. It holds great potential as a tissue engineering tool as it can be used to place cells into specific patterns. As the human central nervous system (CNS) cannot be studied in vivo at the cellular and molecular level, in vitro CNS models are needed. Human neural stem cells (hNSCs) are the CNS building block as they can generate both neurones and glial cells. Methods: Here we assessed for the first time how hNSCs respond to BES. To this purpose, different hNSC lines were sprayed at 10 kV and their ability to survive, grow and differentiate was assessed at different time points. Results: BES induced only a small and transient decrease in hNSC metabolic activity, from which the cells recovered by day 6, and no significant increase in cell death was observed, as assessed by flow cytometry. Furthermore, bio-electrosprayed hNSCs differentiated as efficiently as controls into neurones, astrocytes and oligodendrocytes, as shown by morphological, protein and gene expression analysis. Conclusions: This study highlights the robustness of hNSCs and identifies BES as a suitable technology that could be developed for the direct deposition of these cells in specific locations and configurations.

Bio-electrosprayed human neural stem cells are viable and maintain their differentiation potential

Background: Bio-electrospray (BES) is a jet-based delivery system driven by an electric field that has the ability to form micro to nano-sized droplets. It holds great potential as a tissue engineering tool as it can be used to place cells into specific patterns. As the human central nervous system (CNS) cannot be studied in vivo at the cellular and molecular level, in vitro CNS models are needed. Human neural stem cells (hNSCs) are the CNS building block as they can generate both neurones and glial cells. Methods: Here we assessed for the first time how hNSCs respond to BES. To this purpose, different hNSC lines were sprayed at 10 kV and their ability to survive, grow and differentiate was assessed at different time points. Results: BES induced only a small and transient decrease in hNSC metabolic activity, from which cells recovered by day 6, and no significant increase in cell death was observed, as assessed by flow cytometry. Furthermore, bio-electrosprayed hNSCs differentiated as efficiently as controls into neurones, astrocytes and oligodendrocytes as shown by morphological, protein and gene expression analysis. Conclusions: This study highlights the robustness of hNSCs and identifies BES as a suitable technology that could be developed for the direct deposition of these cells in specific locations and configurations.

Biofabrication of valentine-shaped heart with a composite hydrogel and sacrificial material

3D bioprinting represents a potential solution for organs regeneration, however, the production of complex tissues and organs that are in large size, randomly shaped, hollow, and contain integrated pre-vascularization still faces multiple challenges. This study aimed to test the feasibility of our 3D printing scheme for the manufacturing of micro-fluid channel networks complex three-dimensional tissue structures. The reverse engineering software was used to design the CAD model and polyvinyl alcohol (PVA) was used as the sacrificial material to print the sacrificial stent use the bioprinter nozzle 1. Hydrogel composite H9c2 and human umbilical vein endothelial cells (HUVECs) were mixed with sodium alginate, agarose solution and platelet-rich plasma (PRP) as cellular bioink, which was extruded through nozzle 2 to deposit the internal pores of the sacrificial scaffold. The scaffold dissolved, change to a flexible, hollow and micro-fluid channel networks complex structure. The 3D-bioprinting technology can construct a micro-fluid channel networks valentine heart with a self-defined height and hollow in suitable mechanical properties. The cells proliferate and maintain their biological properties within the printed constructs. This study demonstrates that valentine heart-like constructs can be fabricated with 3D bioprinting using sacrificial and hydrogel materials.

Electrospraying: Possibilities and Challenges of Engineering Carriers for Biomedical Applications-A Mini Review

Electrospraying, a liquid atomization-based technique, has been used to produce and formulate micro/nanoparticular cargo carriers for various biomedical applications, including drug delivery, biomedical imaging, implant coatings, and tissue engineering. In this mini review, we begin with the main features of electrospraying methods to engineer carriers with various bioactive cargos, including genes, growth factors, and enzymes. In particular, this review focuses on the improvement of traditional electrospraying technology for the fabrication of carriers for living cells and providing a suitable condition for gene transformation. Subsequently, the major applications of the electrosprayed carriers in the biomedical field are highlighted. Finally, we finish with conclusions and future perspectives of electrospraying for high efficiency and safe production.

Boiling Method-Based Zinc Oxide Nanorods for Enhancement of Adipose-Derived Stem Cell Proliferation

Adipose-derived stem cells (ASCs) are typically expanded to acquire large numbers of cells for therapeutic applications. Diverse stimuli such as sphingosylphosphocholine and vitamin C have been used to increase the production yield and regenerative potential of ASCs. In the present study, we hypothesized that ZnO nanorods have promising potential for the enhancement of ASC proliferation. ZnO nanorods were prepared using three different methods: grinding and boiling at low temperature with and without surfactant. The physicochemical properties of the nanorods such as their crystallinity, morphology, size, and solvent compatibility were evaluated, and then, the ability of the synthesized ZnO nanorods to enhance ASC proliferation was investigated. Scanning electron microscopy images of all of the ZnO powders showed rod-shaped nanoflakes with lengths of 200-500 nm. Notably, although ZnO-G produced by the grinding method was well dispersed in ethanol, atomic force microscopy images of dispersions of both ZnO-B from boiling methods and ZnO-G indicated the presence of clusters of ZnO nanorods. In contrast, ZnO-B was freely dispersible in 5% dextrose of water and dimethyl sulfoxide, whereas ZnO-G and ZnO-M, produced by boiling with ethanolamine, were not. All three types of ZnO nanorods increased the proliferation of ASCs in a dose-dependent manner. These results collectively suggest that ZnO nanorods have promising potential for use as an agent for the enhancement of ASC proliferation.

Assessment of the potential of a high frequency acoustomicrofluidic nebulisation platform for inhaled stem cell therapy

This study demonstrates the use of a novel high frequency acoustic nebulisation platform as an effective aerosolisation technique for inhaled mesenchymal stem cell (MSC) therapy.

Neurotoxic effects of local anesthetics on the mouse neuroblastoma NB2a cell line

Local anesthetics are used clinically for peripheral nerve blocks, epidural anesthesia, spinal anesthesia and pain management; large concentrations, continuous application and long exposure time can cause neurotoxicity. The mechanism of neurotoxicity caused by local anesthetics is unclear. Neurite outgrowth and apoptosis can be used to evaluate neurotoxic effects. Mouse neuroblastoma cells were induced to differentiate and generate neurites in the presence of local anesthetics. The culture medium was removed and replaced with serum-free medium plus 20 μl combinations of epidermal growth factor and fibroblast growth factor containing tetracaine, prilocaine, lidocaine or procaine at concentrations of 1, 10, 25, or 100 μl prior to neurite measurement. Cell viability, iNOS, eNOS and apoptosis were evaluated. Local anesthetics produced toxic effects by neurite inhibition at low concentrations and by apoptosis at high concentrations. There was an inverse relation between local anesthetic concentrations and cell viability. Comparison of different local anesthetics showed toxicity, as assessed by cell viability and apoptotic potency, in the following order: tetracaine > prilocaine > lidocaine > procaine. Procaine was the least neurotoxic local anesthetic and because it is short-acting, may be preferred for pain prevention during short procedures.