Tridimensional cell culture of dermal fibroblasts promotes exosome-mediated secretion of extracellular matrix proteins

Direct extrusion of multifascicle prevascularized human skeletal muscle for volumetric muscle loss surgery

Skeletal muscle is composed of multiple fascicles, which are parallel bundles of muscle fibers surrounded by connective tissues that contain blood vessels and nerves. Here, we fabricated multifascicle human skeletal muscle scaffolds that mimic the natural structure of human skeletal muscle bundles using a seven-barrel nozzle. For the core material to form the fascicle structure, human skeletal myoblasts were encapsulated in Matrigel with calcium chloride. Meanwhile, the shell that plays a role as the connective tissue, human fibroblasts and human umbilical vein endothelial cells within a mixture of porcine muscle decellularized extracellular matrix and sodium alginate at a 95:5 ratio was used. We assessed four types of extruded scaffolds monolithic-monoculture (Mo-M), monolithic-coculture (Mo-C), multifascicle-monoculture (Mu-M), and multifascicle-coculture (Mu-C) to determine the structural effect of muscle mimicking scaffold. The Mu-C scaffold outperformed other scaffolds in cell proliferation, differentiation, vascularization, mechanical properties, and functionality. In an in vivo mouse model of volumetric muscle loss, the Mu-C scaffold effectively regenerated the tibialis anterior muscle defect, demonstrating its potential for volumetric muscle transplantation. Our nozzle will be further used to produce other volumetric functional tissues, such as tendons and peripheral nerves.

Bioengineering Human Upper Respiratory Mucosa: A Systematic Review of the State of the Art of Cell Culture Techniques

BACKGROUND

The upper respiratory mucosa plays a crucial role in both the physical integrity and immunological function of the respiratory tract. However, in certain situations such as infections, trauma, or surgery, it might sustain damage. Tissue engineering, a field of regenerative medicine, has found applications in various medical fields including but not limited to plastic surgery, ophthalmology, and urology. However, its application to the respiratory system remains somewhat difficult due to the complex morphology and histology of the upper respiratory tract. To date, a culture protocol for producing a handleable, well-differentiated nasal mucosa has yet to be developed. The objective of this review is to describe the current state of research pertaining to cell culture techniques used for producing autologous healthy human upper respiratory cells and mucosal tissues, as well as describe its clinical applications.

METHODS

A search of the relevant literature was carried out with no time restriction across Embase, Cochrane, PubMed, and Medline Ovid databases. Keywords related to "respiratory mucosa" and "culture techniques of the human airway" were the focus of the search strategy for this review. The risk of bias in retained studies was assessed using the Joanna Briggs Institute's (JBI) critical appraisal tools for qualitative research. A narrative synthesis of our results was then conducted.

RESULTS

A total of 33 studies were included in this review, and thirteen of these focused solely on developing a cell culture protocol without further use. The rest of the studies used their own developed protocol for various applications such as cystic fibrosis, pharmacological, and viral research. One study was able to develop a promising model for nasal mucosa that could be employed as a replacement in nasotracheal reconstructive surgery.

CONCLUSIONS

This systematic review extensively explored the current state of research regarding cell culture techniques for producing tissue-engineered nasal mucosa. Bioengineering the nasal mucosa holds great potential for clinical use. However, further research on mechanical properties is essential, as the comparison of engineered tissues is currently focused on morphology rather than comprehensive mechanical assessments.

Enigmatic exosomal connection in lung cancer drug resistance

Lung cancer remains a significant global health concern with limited treatment options and poor prognosis, particularly in advanced stages. Small extracellular vesicles such as exosomes, secreted by cancer cells, play a pivotal role in mediating drug resistance in lung cancer. Exosomes have been found to facilitate intercellular communication by transferring various biomolecules between cancer cells and their microenvironment. Additionally, exosomes can transport signaling molecules promoting cancer cell survival and proliferation conferring resistance to chemotherapy. Moreover, exosomes can modulate the tumor microenvironment by inducing phenotypic changes hindering drug response. Understanding the role of exosomes in mediating drug resistance in lung cancer is crucial for developing novel therapeutic strategies and biomarkers to overcome treatment limitations. In this review, we summarize the current knowledge on conventional and emerging drug resistance mechanisms and the involvement of exosomes as well as exosome-mediated factors mediating drug resistance in lung cancer.

Effect of 3D and 2D cell culture systems on trophoblast extracellular vesicle physico-chemical characteristics and potency

The growing understanding of the role of extracellular vesicles (EVs) in embryo-maternal communication has sparked considerable interest in their therapeutic potential within assisted reproductive technology, particularly in enhancing implantation success. However, the major obstacle remains the large-scale production of EVs, and there is still a gap in understanding how different culture systems affect the characteristics of the EVs. In the current study, trophoblast analogue human chorionic carcinoma cell line was cultivated in both conventional monolayer culture (2D) and as spheroids in suspension culture (3D) and how the cell growth environment affects the physical, biochemical and cellular signalling properties of EVs produced by them was studied. Interestingly, the 3D system was more active in secreting EVs compared to the 2D system, while no significant differences were observed in terms of morphology, size, and classical EV protein marker expression between EVs derived from the two culture systems. There were substantial differences in the proteomic cargo profile and cellular signalling potency of EVs derived from the two culture systems. Notably, 2D EVs were more potent in inducing a cellular response in endometrial epithelial cells (EECs) compared to 3D EVs. Therefore, it is essential to recognize that the biological activity of EVs depends not only on the cell of origin but also on the cellular microenvironment of the parent cell. In conclusion, caution is warranted when selecting an EV production platform, especially for assessing the functional and therapeutic potential of EVs through in vitro studies.

Equine bone marrow MSC-derived extracellular vesicles mitigate the inflammatory effects of interleukin-1β on navicular tissues in vitro

BACKGROUND

Safe, efficacious therapy for treating degenerate deep digital flexor tendon (DDFT) and navicular bone fibrocartilage (NBF) in navicular horses is critically necessary. While archetypal orthobiologic therapies for navicular disease are used empirically, their safety and efficacy are unknown. Mesenchymal stem cell-derived extracellular vesicles (EV) may overcome several limitations of current orthobiologic therapies.

OBJECTIVES

To (1) characterise cytokine and growth factor profiles of equine bone marrow mesenchymal stem cell (BM-MSC)-derived extracellular vesicles (BM-EV) and (2) evaluate the in vitro anti-inflammatory and extracellular matrix (ECM) protective potentials of BM-EV on DDFT and NBF explant co-cultures in an IL-1β inflammatory environment.

STUDY DESIGN

In vitro experimental study.

METHODS

Cytokines (IL-1β, IL-6, IL-10, IL-1ra and TNF-α) and growth factors (TGFβ1, VEGF, IGF1 and PDGF) in equine BM-EV isolated via ultracentrifugation and precipitation methods were profiled. Forelimb DDFT and NBF explant co-cultures from seven horses were exposed to media alone, or media containing 2 × 109 ± 0.1 × 109 particles/mL or 10 μg/mL BM-EV (BM-EV), 10 ng/mL interleukin-1β (IL-1β), or IL-1β + BM-EV for 48 h. Co-culture media IL-6, TNF-α, MMP-3, MMP-13 concentrations and explant sulphated glycosaminoglycan (sGAG) content were quantified.

RESULTS

IL-6, IGF1 and VEGF concentrations were 102.1 (37.61-256.2) and 182.3 (163.1-226.3), 72.3 (8-175.6) and 2.4 (0.1-2.6), 108.3 (38.3-709.1) and 211.4 (189.1-318.2) pg/mL per 2 × 109 ± 0.1 × 109 particles/mL or 10 μg/mL 10 μg of BM-EV isolated via ultracentrifugation and precipitation methods, respectively. Co-culture media MMP-3 in BM-EV- (p = 0.03) and BM-EV + IL-1β-treated (p = 0.01) groups were significantly lower than the respective media and IL-1β groups. DDFT explant sGAG content of BM-EV (p = 0.003) and BM-EV + IL-1β groups were significantly higher compared with IL-1β group.

MAIN LIMITATIONS

Specimen numbers are limited, in vitro model may not replicate clinical case conditions, lack of non-MSC-derived EV control group.

CONCLUSIONS

Equine BM-EV contains IL-6 and growth factors, IGF1 and VEGF. The anti-inflammatory and ECM protective potentials of BM-EV were evident as increased IL-6 and decreased MMP-3 concentrations in the DDFT-NBF explant co-culture media. These results support further evaluation of BM-EV as an acellular and 'off-the-shelf' intra-bursal/intrasynovial therapy for navicular pathologies.

Heterozygous NF1 dermal fibroblasts modulate exosomal content to promote angiogenesis in a tissue-engineered skin model of neurofibromatosis type-1

Neovascularization is a critical process in tumor progression and malignant transformation associated with neurofibromatosis type 1 (NF1). Indeed, fibroblasts are known to play a key role in the tumoral microenvironment modification by producing an abundant collagenous matrix, but their contribution in paracrine communication pathways is poorly understood. Here, we hypothesized that NF1 heterozygosis in human dermal fibroblasts could promote angiogenesis through exosomes secretion. The purposes of this study are to identify the NF1 fibroblast-derived exosome protein contents and to determine their proangiogenic activity. Angiogenic proteome measurement confirmed the overexpression of VEGF and other proteins involved in vascularization. Tube formation of microvascular endothelial cells was also enhanced in presence of exosomes derived from NF1 skin fibroblasts. NF1 tissue-engineered skin (NF1-TES) generation showed a significantly denser microvessels networks compared to healthy controls. The reduction of exosomes production with an inhibitor treatment demonstrated a drastic decrease in blood vessel formation within the dermis. Our results suggest that NF1 haploinsufficiency alters the dermal fibroblast function and creates a pro-angiogenic signal via exosomes, which increases the capillary formation. This study highlights the potential of targeting exosome secretion and angiogenesis for therapeutic interventions in NF1.

Various Three-Dimensional Culture Methods and Cell Types for Exosome Production

Cell-based therapies have been used as promising treatments for several untreatable diseases. However, cell-based therapies have side effects such as tumorigenesis and immune responses. To overcome these side effects, therapeutic effects of exosomes have been researched as replacements for cell-based therapies. In addition, exosomes reduced the risk that can be induced by cell-based therapies. Exosomes contain biomolecules such as proteins, lipids, and nucleic acids that play an essential role in cell-cell and cell-matrix interactions during biological processes. Since the introduction of exosomes, those have been proven perpetually as one of the most effective and therapeutic methods for incurable diseases. Much research has been conducted to enhance the properties of exosomes, including immune regulation, tissue repair, and regeneration. However, yield rate of exosomes is the critical obstacle that should be overcome for practical cell-free therapy. Three-dimensional (3D) culture methods are introduced as a breakthrough to get higher production yields of exosomes. For example, hanging drop and microwell were well known 3D culture methods and easy to use without invasiveness. However, these methods have limitation in mass production of exosomes. Therefore, a scaffold, spinner flask, and fiber bioreactor were introduced for mass production of exosomes isolated from various cell types. Furthermore, exosomes treatments derived from 3D cultured cells showed enhanced cell proliferation, angiogenesis, and immunosuppressive properties. This review provides therapeutic applications of exosomes using 3D culture methods.

The Skin Microbiome: Current Landscape and Future Opportunities

Our skin is the largest organ of the body, serving as an important barrier against the harsh extrinsic environment. Alongside preventing desiccation, chemical damage and hypothermia, this barrier protects the body from invading pathogens through a sophisticated innate immune response and co-adapted consortium of commensal microorganisms, collectively termed the microbiota. These microorganisms inhabit distinct biogeographical regions dictated by skin physiology. Thus, it follows that perturbations to normal skin homeostasis, as occurs with ageing, diabetes and skin disease, can cause microbial dysbiosis and increase infection risk. In this review, we discuss emerging concepts in skin microbiome research, highlighting pertinent links between skin ageing, the microbiome and cutaneous repair. Moreover, we address gaps in current knowledge and highlight key areas requiring further exploration. Future advances in this field could revolutionise the way we treat microbial dysbiosis associated with skin ageing and other pathologies.

In Vitro 3D Modeling of Neurodegenerative Diseases

The study of neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease, Huntington's disease, or amyotrophic lateral sclerosis) is very complex due to the difficulty in investigating the cellular dynamics within nervous tissue. Despite numerous advances in the in vivo study of these diseases, the use of in vitro analyses is proving to be a valuable tool to better understand the mechanisms implicated in these diseases. Although neural cells remain difficult to obtain from patient tissues, access to induced multipotent stem cell production now makes it possible to generate virtually all neural cells involved in these diseases (from neurons to glial cells). Many original 3D culture model approaches are currently being developed (using these different cell types together) to closely mimic degenerative nervous tissue environments. The aim of these approaches is to allow an interaction between glial cells and neurons, which reproduces pathophysiological reality by co-culturing them in structures that recapitulate embryonic development or facilitate axonal migration, local molecule exchange, and myelination (to name a few). This review details the advantages and disadvantages of techniques using scaffolds, spheroids, organoids, 3D bioprinting, microfluidic systems, and organ-on-a-chip strategies to model neurodegenerative diseases.

RNF213 Loss-of-Function Promotes Angiogenesis of Cerebral Microvascular Endothelial Cells in a Cellular State Dependent Manner

Enhanced and aberrant angiogenesis is one of the main features of Moyamoya disease (MMD) pathogenesis. The ring finger protein 213 (RNF213) and the variant p.R4810K have been linked with higher risks of MMD and intracranial arterial occlusion development in east Asian populations. The role of RNF213 in diverse aspects of the angiogenic process, such as proliferation, migration and capillary-like formation, is well-known but has been difficult to model in vitro. To evaluate the effect of the RNF213 MMD-associated gene on the angiogenic activity, we have generated RNF213 knockout in human cerebral microvascular endothelial cells (hCMEC/D3-RNF213^-/-) using the CRISPR-Cas9 system. Matrigel-based assay and a tri-dimensional (3D) vascularized model using the self-assembly approach of tissue engineering were used to assess the formation of capillary-like structures. Quite interestingly, this innovative in vitro model of MMD recapitulated, for the first time, disease-associated pathophysiological features such as significant increase in angiogenesis in confluent endothelial cells devoid of RNF213 expression. These cells, grown to confluence, also showed a pro-angiogenic signature, i.e., increased secretion of soluble pro-angiogenic factors, that could be eventually used as biomarkers. Interestingly, we demonstrated that that these MMD-associated phenotypes are dependent of the cellular state, as only noted in confluent cells and not in proliferative RNF213-deficient cells.