A Novel Methodology for Bio-electrospraying Mesenchymal Stem Cells that Maintains Differentiation, Immunomodulatory and Pro-reparative Functions

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.

Investigating the potential of oncolytic viruses for cancer treatment via MSC delivery

Mesenchymal stem cells (MSCs) have attracted considerable interest as a promising approach for cancer treatment due to their ability to undergo tumor-trophic migration. MSCs possess the unique ability to selectively migrate to tumors, making them an excellent candidate for targeted delivery of oncolytic viruses (OVs) to treat isolated tumors and metastatic malignancies. OVs have attracted attention as a potential treatment for cancer due to their ability to selectively infect and destroy tumor cells while sparing normal cells. In addition, OVs can induce immunogenic cell death and contain curative transgenes in their genome, making them an attractive candidate for cancer treatment in combination with immunotherapies. In combination with MSCs, OVs can modulate the tumor microenvironment and trigger anti-tumor immune responses, making MSC-releasing OVs a promising approach for cancer treatment. This study reviews researches on the use of MSC-released OVs as a novel method for treating cancer. Video Abstract.

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.

Differentiation of adipose-derived stem cells to chondrocytes using electrospraying

An important challenge in the fabrication of tissue engineered constructs for regenerative medical applications is the development of processes capable of delivering cells and biomaterials to specific locations in a consistent manner. Electrospraying live cells has been introduced in recent years as a cell seeding method, but its effect on phenotype nor genotype has not been explored. A promising candidate for the cellular component of these constructs are human adipose-derived stem cells (hASCs), which are multipotent stem cells that can be differentiated into fat, bone, and cartilage cells. They can be easily and safely obtained from adipose tissue, regardless of the age and sex of the donor. Moreover, these cells can be maintained and expanded in culture for long periods of time without losing their differentiation capacity. In this study, hASCs directly incorporated into a polymer solution were electrosprayed, inducing differentiation into chondrocytes, without the addition of any exogenous factors. Multiple studies have demonstrated the effects of exposing hASCs to biomolecules—such as soluble growth factors, chemokines, and morphogens—to induce chondrogenesis. Transforming growth factors (e.g., TGF-β) and bone morphogenetic proteins are particularly known to play essential roles in the induction of chondrogenesis. Although growth factors have great therapeutic potential for cell-based cartilage regeneration, these growth factor-based therapies have presented several clinical complications, including high dose requirements, low half-life, protein instability, higher costs, and adverse effects in vivo. The present data suggests that electrospraying has great potential as hASCs-based therapy for cartilage regeneration.

Modulating the foreign body response of implants for diabetes treatment

Diabetes Mellitus is a group of diseases characterized by high blood glucose levels due to patients' inability to produce sufficient insulin. Current interventions often require implants that can detect and correct high blood glucose levels with minimal patient intervention. However, these implantable technologies have not reached their full potential in vivo due to the foreign body response and subsequent development of fibrosis. Therefore, for long-term function of implants, modulating the initial immune response is crucial in preventing the activation and progression of the immune cascade. This review discusses the different molecular mechanisms and cellular interactions involved in the activation and progression of foreign body response (FBR) and fibrosis, specifically for implants used in diabetes. We also highlight the various strategies and techniques that have been used for immunomodulation and prevention of fibrosis. We investigate how these general strategies have been applied to implants used for the treatment of diabetes, offering insights on how these devices can be further modified to circumvent FBR and fibrosis.

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.

Liquefied Microcapsules as Dual-Microcarriers for 3D+3D Bottom-Up Tissue Engineering

Cell encapsulation systems must ensure the diffusion of molecules to avoid the formation of necrotic cores. The architectural design of hydrogels, the gold standard tissue engineering strategy, is thus limited to a microsize range. To overcome such a limitation, liquefied microcapsules encapsulating cells and microparticles are proposed. Microcapsules with controlled sizes with average diameters of 608.5 ± 122.3 µm are produced at high rates by electrohydrodynamic atomization, and arginyl-glycyl-aspartic acid (RGD) domains are introduced in the multilayered membrane. While cells and microparticles interact toward the production of confined microaggregates, on the outside cell-mediated macroaggregates are formed due to the aggregation of microcapsules. The concept of simultaneous aggregation is herein termed as 3D+3D bottom-up tissue engineering. Microcapsules are cultured alone (microcapsule¹ ) or on top of 2D cell beds composed of human umbilical vein endothelial cells (HUVECs) alone (microcapsule² ) or cocultured with fibroblasts (microcapsule³ ). Microcapsules are able to support cell encapsulation shown by LiveDead, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphofenyl)-2H-tetrazolium (MTS), and dsDNA assays. Only microcapsule³ are able to form macroaggregates, as shown by F-actin immunofluorescence. The bioactive 3D system also presented alkaline phosphatase activity, thus allowing osteogenic differentiation. Upon implantation using the chick chorioallontoic membrane (CAM) model, microcapsules recruit a similar number of vessels with alike geometric parameters in comparison with CAMs supplemented with basic fibroblast growth factor (bFGF).

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.

Delivery of nucleic acids to ex vivo porcine airways using electrospray

AIM OF THE STUDY

Nucleic acid-based therapies have the potential to provide clinically meaningful benefit across a wide spectrum of lung disease. However, in vivo delivery remains a challenge. Here we examined the feasibility of using electrospray to deliver nucleic acids to both porcine tracheal tissue sections and whole lung ex vivo.

MATERIALS AND METHODS

The effect of electrospray solution, emitter gauge, flow rate and voltage on plasmid DNA integrity was examined by analyzing supercoiled:open circle structure ratio by gel electrophoresis. Optimal parameters were used to deliver luciferase DNA and mRNA and siRNA-FITC to tracheal tissue sections. Luciferase mRNA was delivered to whole porcine lungs ex vivo using a catheter and bronchoscope system. Luciferase activity and fluorescence were analyzed by luminometry and microscopy respectively.

RESULTS

The incidence of DNA plasmid nicking was greatest in a low salt solution without ethanol compared with 1% and 20% ethanol with salt. From a range of emitters tested, a 32 gauge emitter produced the best supercoiled:open circle structure ratio, likely because less voltage was required to produce a stable electrospray with this emitter. Lower flow rates also showed a trend towards reduced DNA nicking. GFP DNA electrosprayed at 5 kV and 6 kV resulted in lower levels of GFP expression in A549 lung cells following lipofection compared with 3 kV and 4 kV. Optimised parameters of 20% ethanol solution, 32 gauge emitter, low flow rates and voltages of 3-5 kV, nucleic acid molecules were successful for delivery of luciferase DNA and mRNA as well as siRNA-FITC to porcine tracheal tissue sections and for delivery of luciferase mRNA to whole porcine lungs via bronchoscope.

CONCLUSIONS

We report ex vivo delivery of nucleic acids to porcine lung tissue via electrospray and bronchoscopic electrospray delivery of nucleic acid to an ex vivo porcine lung model.