Stem cell transplantation effectively occludes bronchopleural fistula in an animal model

Efficacy of mesenchymal stem cells in treating tracheoesophageal fistula via the TLR4/NF-κb pathway in beagle macrophages

Background

Tracheoesophageal fistula (TEF) remains a rare but significant clinical challenge, mainly due to the absence of established, effective treatment approaches. The current focus of therapeutic strategy is mainly on fistula closure. However, this approach often misses important factors, such as accelerating fistula contraction and fostering healing processes, which significantly increases the risk of disease recurrence.

Methods

In order to investigate if Mesenchymal Stem Cells (MSCs) can enhance fistula repair, developed a TEF model in beagles. Dynamic changes in fistula diameter were monitored by endoscopy. Concurrently, we created a model of LPS-induced macrophage to replicate the inflammatory milieu typical in TEF. In addition, the effect of MSC supernatant on inflammation mitigation was evaluated. Furthermore, we looked at the role of TLR4/NF-κB pathway plays in the healing process.

Results

Our research revealed that the local administration of MSCs significantly accelerated the fistula's healing process. This was demonstrated by a decline in TEF apoptosis and decrease in the production of pro-inflammatory cytokines. Furthermore, in vivo experiments demonstrated that the MSC supernatant was effective in suppressing pro-inflammatory cytokine expression and alleviating apoptosis in LPS-induced macrophages. These therapeutic effects were mainly caused by the suppression of TLR4/NF-κB pathway.

Conclusion

According to this study, MSCs can significantly improve TEF recovery. They achieve this via modulating apoptosis and inflammatory responses, mainly by selectively inhibiting the TLR4/NF-κB pathway.

Comprehensive assessment of goat adipose tissue-derived mesenchymal stem cells cultured in different media

Mesenchymal stem cells (MSCs) have demonstrated potential in treating livestock diseases that are unresponsive to conventional therapies. MSCs derived from goats, a valuable model for studying orthopaedic disorders in humans, offer insights into bone formation and regeneration. Adipose tissue-derived MSCs (ADSCs) are easily accessible and have a high capacity for expansion. Although the choice of culture media significantly influences the biological properties of MSCs, the optimal media for goat ADSCs (gADSCs) remains unclear. This study aimed to assess the effects of four commonly used culture media on gADSCs' culture characteristics, stem cell-specific immunophenotype, and differentiation. Results showed that MEM, DMEM/F12, and DMEM-LG were superior in maintaining cell morphology and culture parameters of gADSCs, such as cell adherence, metabolic activity, colony-forming potential, and population doubling. Conversely, DMEM-HG exhibited poor performance across all evaluated parameters. The gADSCs cultured in DMEM/F12 showed enhanced early proliferation and lower apoptosis. The cell surface marker distribution exhibited superior characteristics in gADSCs cultured in MEM and DMEM/F12. In contrast, the distribution was inferior in gADSCs cultured in DMEM-LG. DMEM/F12 and DMEM-LG culture media demonstrated a significantly higher potential for chondrogenic differentiation and DMEM-LG for osteogenic differentiation. In conclusion, DMEM/F12 is a suitable culture medium for propagating gADSCs as it effectively maintains cell morphology, growth parameters, proliferation and lower apoptosis while exhibiting desirable expression patterns of MSC-specific markers. These findings contribute to optimising culture conditions for gADSCs, enhancing their potential applications in disease treatment and regenerative medicine.

Mesenchymal Stromal Cell Therapy for Thoracic Surgeons: An Update

Stem cells are undifferentiated cells presenting extensive self-renewal features and the ability to differentiate "in vitro" and "in vivo" into a range of lineage cells, like chondrogenic, osteogenic and adipogenic lineages when cultured in specific inducing media. Two major domains of clinical applications of stem cells in thoracic surgery have been investigated: regenerative medicine, which is a section of translational research in tissue engineering focusing on the replacement, renewal or regeneration of cells, tissues and organs to re-establish damaged physiologic functions; drug loading and delivery, representing a new branch proposing stem cells as carriers to provide selected districts with anti-cancer agents for targeted treatments.

Chinese expert consensus on interventional diagnosis and management of acquired digestive-respiratory tract fistulas (second edition)

Acquired digestive-respiratory tract fistulas occur with abnormal communication between the respiratory tract and digestive tract caused by a variety of benign or malignant diseases, leading to the alimentary canal contents in the respiratory tract. Although various departments have been actively exploring advanced fistula closure techniques, including surgical methods and multimodal therapy, some of which have gotten good clinical effects, there are few large-scale evidence-based medical data to guide clinical diagnosis and treatment. The guidelines update the etiology, classification, pathogenesis, diagnosis, and management of acquired digestive-respiratory tract fistulas. It has been proved that the implantation of the respiratory and digestive stent is the most important and best treatment for acquired digestive-respiratory tract fistulas. The guidelines conduct an in-depth review of the current evidence and introduce in detail the selection of stents, implantation methods, postoperative management and efficacy evaluation.

Development of Bio-artificial Esophageal Tissue Engineering Utilization for Circumferential Lesion Transplantation: A Narrative Review

The esophagus is the gastrointestinal tract's primary organ that transfers bolus into the stomach with peristaltic motion. Therefore, its lesions cause a significant disturbance in the nutrition and digestive system. Esophageal disease treatment sometimes requires surgical procedures that involve removal and circumferential full-thickness replacement. Unlike other organs, the esophagus has a limited regeneration ability and cannot be transplanted from donors. There are various methods of restoring the esophageal continuity; however, they are associated with certain flaws that lead to a non-functional recovery. As an exponentially growing science, tissue engineering has become a leading technique for the development of tissue replacement to repair damaged esophageal segments. Scaffold plays a significant role in the process of tissue engineering, as it acts as a template for the regeneration of growing tissue. A variety of scaffolds have been studied to replace the esophagus. Due to the many tissue quality challenges, the results are still inadequate and need to be improved. The success of esophageal tissue regeneration will finally depend on the scaffold's capability to mimic natural tissue properties and provide a qualified environment for regeneration. Thereby, scaffold fabrication techniques are fundamental. This article reviews the recent developments in esophageal tissue engineering for the treatment of circumferential lesions based on scaffold biomaterial engineering approaches.

Mesenchymal Stem Cell Studies in the Goat Model for Biomedical Research-A Review of the Scientific Literature

Mesenchymal stem cells (MSCs) are multipotent cells, defined by their ability to self-renew, while maintaining the capacity to differentiate into different cellular lineages, presumably from their own germinal layer. MSCs therapy is based on its anti-inflammatory, immunomodulatory, and regenerative potential. Firstly, they can differentiate into the target cell type, allowing them to regenerate the damaged area. Secondly, they have a great immunomodulatory capacity through paracrine effects (by secreting several cytokines and growth factors to adjacent cells) and by cell-to-cell contact, leading to vascularization, cellular proliferation in wounded tissues, and reducing inflammation. Currently, MSCs are being widely investigated for numerous tissue engineering and regenerative medicine applications. Appropriate animal models are crucial for the development and evaluation of regenerative medicine-based treatments and eventual treatments for debilitating diseases with the hope of application in upcoming human clinical trials. Here, we summarize the latest research focused on studying the biological and therapeutic potential of MSCs in the goat model, namely in the fields of orthopedics, dermatology, ophthalmology, dentistry, pneumology, cardiology, and urology fields.

The therapeutic effect of stem cells from human exfoliated deciduous teeth on a rat model of tracheal fistula

Background

Tracheal fistulas (TF) can be dangerous and even fatal in patients. The current treatment is really challenging. Previous studies reported that mesenchymal stem cells (MSCs) could be used to treat respiratory tract fistulas. Stem cells from human exfoliated deciduous teeth (SHED) are considered to be MSC-like cells that may also have the potential to treat the tracheal fistulas. In this study, we investigated the therapeutic effects of SHED in rat tracheal fistula models.

Methods

A total of 80 SD rats were randomly divided into five groups: a sham-operated group, a local PBS group (L-PBS), an intravenous PBS group (I-PBS), a local SHED treatment group (L-SHED), and an intravenous SHED treatment group (I-SHED). The L-SHED and I-SHED groups were given a topical application around the fistula or an intravenous injection of 1*10⁷ SHED via the tail vein, respectively, while the L-PBS and I-PBS groups were given an equivalent volume of PBS through local or intravenous administration. A stereomicroscope was used to observe fistula healing on the 2nd, 3rd, and 5th days following transplantation. On the 7th day, the survival of SHED was observed by immunofluorescence. The pathology of the lungs and fistulas was observed by hematoxylin and eosin (H&E) and Masson staining. The expression levels of the Toll-like receptor 4 (TLR4), interleukin (IL)-1β, IL-33, and IL-4 were measured using immunohistochemistry. The expression levels of TLR4, high mobility group box 1 (HMGB1), and myeloid differentiation factor 88 (MYD88) were studied using western blotting. On day 14, airway responsiveness of rats was detected and analyzed.

Results

Fistula healing in the L-SHED and I-SHED groups was faster than that in their respective PBS groups after transplantation. The fistula diameters in the L-SHED and I-SHED groups were significantly smaller than those in the L-PBS and I-PBS groups on the 3rd day. Moreover, the phenomenon of fibroblast proliferation and new blood vessel growth around the fistula seemed more pronounced in the L-SHED and I-SHED groups. Although no discernible difference was found in airway responsiveness after SHED treatment, the degree of inflammation in the lungs was reduced by intravenous SHED treatment. However, there was no significant reduction in lung inflammation by local SHED treatment. The expression levels of IL-1β and IL-33 were decreased in the I-SHED group, while IL-4 was elevated compared with the I-PBS group. Interestingly, intravenous SHED treatment inhibited the activation of HMGB1/TLR4/MYD88 in the lung tissues of TF rats.

Conclusions

SHED transplantation accelerated the rate of fistula healing in rats. Intravenous SHED treatment reduced lung inflammation. Thus, SHED may have potential in the treatment of tracheal fistula, providing hope for future therapeutic development for TF.

Unplanned Return to the Operating Room after Elective Oncologic Thoracic Surgery: A Further Quality Indicator in Surgical Oncology

Background: An unplanned return to the operating room (UROR) is defined as a readmission to the operating room because of a complication or an untoward outcome related to the initial surgery. The aim of the present report is to evaluate the role of URORs after elective oncologic thoracic surgery. Methods: In the study, 4012 consecutive patients were enrolled; among them, 71 patients (1.76%) had an unplanned return to the operating room. Age, sex, Charlson comorbidity index, induction treatments, type of the first operation, indication to readmission to the operating room and type of second operation, length of stay, complication after reoperation and outcomes were collected. Results: The mean age was 63.3 (SD: 13.0); there were 53 male patients (74.6%); the type of the first procedure was: lower lobectomy (11.3%), middle lobectomy (1.4%), upper lobectomy (22.5%), metastasectomy (5.6%), extrapleural pneumonectomy (4.2%), pneumonectomy (40.9%), pleural biopsy (5.6%) and other procedures (8.5%). Patients presenting complications after UROR had undergone a significantly longer first procedure (p < 0.02), had a longer length of stay (p < 0.001) and had higher post-operative mortality (p < 0.001). Conclusions: The patients experiencing UROR after elective oncologic thoracic surgery have significantly higher morbidity and mortality rates when compared to standard thoracic surgery. Bronchopleural fistula remains the most lethal complication in patients undergoing UROR.

MSC therapy in livestock models

Mesenchymal stem cells (MSCs) have great value as therapeutic tools in a wide array of applications in regenerative medicine. The wide repertoire of cell functions regarding tissue regeneration, immunomodulation, and antimicrobial activity makes MSC-based therapy a strong candidate for treatment options in a variety of clinical conditions and should be studied to expand the current breadth of knowledge surrounding their physiological properties and therapeutic benefits. Livestock models are an appropriate resource for testing the efficacy of MSC therapies for their use in biomedical research and can be used to improve both human health and animal agriculture. Agricultural animal models such as pigs, cattle, sheep, and goats have grown in popularity for in vivo research relative to small animal models due to their overlapping similarities in structure and function that more closely mimic the human body. Cutaneous wound healing, bone regeneration, osteoarthritis, ischemic reperfusion injury, and mastitis recovery represent a few examples of the types of disease states that may be investigated in livestock using MSC-based therapy. Although the cost of agricultural animals is greater than small animal models, the information gained using livestock as a model holds great value for human applications, and in some cases, outcompetes the weight of information gained from rodent models. With emerging fields such as exosome-based therapy, proper in vivo models will be needed for testing efficacy and translational practice, i.e., livestock models should be strongly considered as candidates. The potential for capitalizing on areas that have crossover benefits for both agricultural economic gain and improved health of the animals while minimizing the gap between translational research and clinical practice are what make livestock great choices for experimental MSC models.

Successful use of bio plugs for delayed bronchial closure after pneumonectomy in experimental settings

OBJECTIVES

Cell therapies, such as stem cell suspension injection, are used to treat bronchopleural fistula. Although it is safe and effective, injected cells cannot remain within the bronchioles of the fistula due to cell leakage into the thoracic cavity. Here, we inserted a 'bio plug' into the fistula, produced using cells and a bio-3D printer, to examine the effectiveness of bio plugs for the closure of bronchopleural fistulas, the optimal cell source and the closure mechanism.

METHODS

Bio plugs were made with mesenchymal stem (stromal) cells derived from bone marrow (MSCBM), fibroblasts and rat lung micro-vessel endothelial cells using a bio-3D printer with different cell mixing ratios. Six groups, according to the presence or absence and the type of bio plugs, were compared. The plugs were inserted into the bronchi of F344 rats. The obstruction ratio and histological and immunohistochemical findings were evaluated.

RESULTS

MSCBM+ rat lung micro-vessel endothelial cell group exhibited a higher obstruction ratio among all groups excluding the MSCBM group (P = 0.039). This group had fibrosis and CD31-positive cells and fewer CD68-positive cells than MSCBM and MSCBM+ fibroblast groups.

CONCLUSIONS

Bio plugs with mixed cells, including stem cells, contribute to bronchial closure in the current experimental setting. Endothelial cells effectively maintain the structure in this model. Although bronchial closure for bronchopleural fistula could not be described as clinical conditions were not reproduced, we collected essential data on bronchial closure; however, further experiments are warranted.

Drug delivery to the pediatric upper airway

Pediatric upper airway disorders are frequently life-threatening and require precise assessment and intervention. Targeting these pathologies remains a challenge for clinicians due to the high complexity of pediatric upper airway anatomy and numerous potential etiologies; the most common treatments include systemic delivery of high dose steroids and antibiotics or complex and invasive surgeries. Furthermore, the majority of innovative airway management technologies are only designed and tested for adults, limiting their widespread implementation in the pediatric population. Here, we provide a comprehensive review of the most recent challenges of managing common pediatric upper airway disorders, describe the limitations of current clinical treatments, and elaborate on how to circumvent those limitations via local controlled drug delivery. Furthermore, we propose future advancements in the field of drug-eluting technologies to improve pediatric upper airway management outcomes.

Small Ruminants and Its Use in Regenerative Medicine: Recent Works and Future Perspectives

Simple Summary

Small ruminants such as sheep and goats have been increasingly used as animal models due to their dimensions, physiology and anatomy identical to those of humans. Their low costs, ease of accommodation, great longevity and easy handling make them advantageous animals to be used in a wide range of research work. Although there is already a lot of scientific literature describing these species, their use still lacks some standardization. The purpose of this review is to summarize the general principles related to the use of small ruminants as animal models for scientific research.

Abstract

Medical and translational scientific research requires the use of animal models as an initial approach to the study of new therapies and treatments, but when the objective is an exploration of translational potentialities, classical models fail to adequately mimic problems in humans. Among the larger animal models that have been explored more intensely in recent decades, small ruminants, namely sheep and goats, have emerged as excellent options. The main advantages associated to the use of these animals in research works are related to their anatomy and dimensions, larger than conventional laboratory animals, but very similar to those of humans in most physiological systems, in addition to their low maintenance and feeding costs, tendency to be docile, long life expectancies and few ethical complications raised in society. The most obvious disadvantages are the significant differences in some systems such as the gastrointestinal, and the reduced amount of data that limits the comparison between works and the validation of the characterization essays. Despite everything, recently these species have been increasingly used as animal models for diseases in different systems, and the results obtained open doors for their more frequent and advantageous use in the future. The purpose of this review is to summarize the general principles related to the use of small ruminants as animal models, with a focus on regenerative medicine, to group the most relevant works and results published recently and to highlight the potentials for the near future in medical research.

Autologous Multilayered Fibroblast Sheets Can Reinforce Bronchial Stump in a Rat Model

Bronchopleural fistula is one of the most serious postoperative complications caused by the incomplete healing of a bronchial stump. Fibroblasts play an important role in wound healing by facilitating connective tissue formation and inducing angiogenesis. We developed a method for production of multilayered fibroblast sheets that secreted some growth factors and promoted wound healing. The present study aimed to assess the treatment effect of multilayered fibroblast sheets on bronchial stump healing. In this rat model, left pneumonectomy was performed, and multilayered fibroblast sheets derived from autologous oral mucosal tissues were transplanted to the bronchial stump. The changes in the bronchial stump were examined macroscopically, histologically, and mechanically. The fibroblast sheets promoted the formation of thick connective tissues around the bronchial stump. The formed connective tissues were accompanied by new blood vessels, and fibrosis was observed over time. Then, 7 days after the transplantation of the fibroblast sheets, the bronchial wall became significantly thicker, and the area of the blood vessels for the bronchial wall tissues was significantly larger in the experimental group than in the control group. In addition, the burst pressure in the bronchial stump was significantly higher in the experimental group than in the control group. Bronchial stumps were reinforced by the transplantation of multilayered fibroblast sheets derived from autologous oral mucosal tissues.

Diagnosis and Treatment of Primary and Secondary Lung Cancers

Primary and secondary lung cancers are the most common clinical conditions that thoracic surgeons have to deal with: primary lung cancer, in fact, is one of the most frequently diagnosed cancers and is the leading cause of cancer-related death worldwide [...].

The Impact of Multidisciplinary Team Meetings on Patient Management in Oncologic Thoracic Surgery: A Single-Center Experience

BACKGROUND

the aim of this paper is to quantify multidisciplinary team meeting (MDT) impact on the decisional clinical pathway of thoracic cancer patients, assessing the modification rate of the initial out-patient evaluation.

METHODS

the impact of MDT was classified as follows: confirmation: same conclusions as out-patient hypothesis; modification: change of out-patient hypothesis; implementation: definition of a clear clinical track/conclusion for patients that did not receive any clinical hypothesis; further exams required: the findings that emerged in the MDT meeting require further exams.

RESULTS

one thousand consecutive patients evaluated at MDT meetings were enrolled. Clinical settings of patients were: early stage lung cancer (17.4%); locally advanced lung cancer (27.4%); stage IV lung cancer (9.8%); mesothelioma (1%); metastases to the lung from other primary tumors (4%); histologically proven or suspected recurrence from previous lung cancer (15%); solitary pulmonary nodule (19.2%); mediastinal tumors (3.4%); other settings (2.8%).

CONCLUSIONS

MDT meetings impact patient management in oncologic thoracic surgery by modifying the out-patient clinical hypothesis in 10.6% of cases; the clinical settings with the highest decisional modification rates are "solitary pulmonary nodule" and "proven or suspected recurrence" with modification rates of 14.6% and 13.3%, respectively.

Biomimetic Design for Bio-Matrix Interfaces and Regenerative Organs

The urgent demand for transplanted organs has motivated the development of regenerative medicine to biomimetically reconstruct the structure and function of natural tissues or organs. The prerequisites for constructing multicellular organs include specific cell sources, suitable scaffolding material, and interconnective biofunctional interfaces. As some of the most complex systems in nature, human organs, tissues, and cellular units have unique "bio-matrix" physicochemical interfaces. Human tissues support a large number of cells with distinct biofunctional interfaces for compartmentalization related to metabolism, material exchange, and physical barriers. These naturally shaped biofunctional interfaces support critical metabolic functions that drive adaptive human behavior. In contrast, mutations and disorders during organogenesis can disrupt these interfaces as a consequence of disease and trauma. To replicate the appropriate structure and physiological function of tissues and organs, the biomaterials used in these approaches should have properties that mimic those of natural biofunctional interfaces. In this review, the focus is on the biomimetic design of functional interfaces and hierarchical structures for four regenerative organs, liver, kidney, lung, heart, and the immune system. Research on these organs provides understanding of cell-matrix interactions for hierarchically bioinspired material engineering, and guidance for the design of bioartificial organs. Finally, we provide perspectives on future challenges in biofunctional interface designs and discuss the obstacles that remain toward the generation of functional bioartificial organs.

7-T MRI tracking of mesenchymal stromal cells after lung injection in a rat model

Background

Mesenchymal stromal cells (MSCs) are able to migrate and engraft at sites of inflammation, injuries, and tumours, but little is known about their fate after local injection. The purpose of this study is to perform MSC tracking, combining in vivo 7-T magnetic resonance imaging (MRI) and histological assessment, following lung injection in a rat model.

Methods

Five lungs were injected with ferumoxide-labelled MSCs and five with perfluorocarbon-labelled MSCs and underwent 7-T MRI. MRI acquisitions were recorded immediately (T₀), at 24 h (T₂₄) and/or 48 h (T₄₈) after injection. For each rat, labelled cells were assessed in the main organs by MRI. Target organs were harvested under sterile conditions from rats sacrificed 0, 24, or 48 h after injection and fixed for histological analysis via confocal and structured illumination microscopy.

Results

Ferumoxide-labelled MSCs were not detectable in the lungs, whereas they were not visible in the distant sites. Perfluorocarbon-labelled MSCs were seen in 5/5 injected lungs at T₀, in 1/2 at T₂₄, and in 1/3 at T₄₈. The fluorine signal in the liver was seen in 3/5 at T₀, in 1/2 at T24, and in 2/3 at T₄₈. Post-mortem histology confirmed the presence of MSCs in the injected lung.

Conclusions

Ferumoxide-labelled cells were not seen at distant sites; a linear decay of injected perfluorocarbon-labelled MSCs was observed at T₀, T₂₄, and T₄₈ in the lung. In more than half of the experiments, perfluorocarbon-labelled MSCs scattering to the liver was observed, with a similar decay over time as observed in the lung.

Recent developments and advances in secondary prevention of lung cancer

Lung cancer prevention may include primary prevention strategies, such as corrections of working conditions and life style - primarily smoking cessation - as well as secondary prevention strategies, aiming at early detection that allows better survival rates and limited resections. This review summarizes recent developments and advances in secondary prevention, focusing on recent technological tools for an effective early diagnosis.

Injection bronchoplasty with carboxymethlycellulose with cystoscopy needle for neonatal persistent bronchopleural fistulae

OBJECTIVE

We describe the novel use of injectable carboxymethylcellulose to close a persistent bronchopleural fistula (BPF) in a neonate who underwent an ex utero intrapartum treatment (EXIT) after aborted fetoscopy.

METHODS

In this case, a patient with laryngeal atresia underwent fetoscopy that was halted after concern for instruments within the mediastinum, and thus ultimately required an EXIT to establish an airway. Bilateral pneumothoraces and eventually multiple BPF were identified that continued to persist despite multiple attempts at removal of chest tubes over a four-week period. We look at the role of endoscopy and a substance often used in the larynx to help close a persistent BPF.

RESULTS

At initial bronchoscopy, no BPF was identified, but at subsequent evaluation due to persistent pneumothorax, we used increased positive end expiratory pressure to help reveal the fistula. Given the bronchial location of the fistula, traditional laryngeal instruments could not be used, requiring the use of urologic cystoscopy needles to assist in accessing these challenging locations. At postoperative day 2 from the injection, the chest tube was removed and did not require replacement.

CONCLUSION

There are many methods to help treat BPF. The endoscopic injection of carboxymethylcellulose adds a technique to the pediatric otolaryngologist's armamentarium.

Closure of Bronchopleural Fistula with Mesenchymal Stem Cells: Case Report and Brief Literature Review

Closure of bronchopleural fistula remains a difficult challenge for clinicians. Although several therapeutic approaches have been proposed, the clinical results are commonly unsatisfactory. Previous reports have indicated that autologous mesenchymal stem cells (MSCs) are useful for aiding treatment of bronchopleural fistula. We report here the use of umbilical cord MSCs to effect the successful closure of a bronchopleural fistula (5 mm) in a 33-year-old woman 6 months after a lobectomy. A review of the relevant literature is included. The use of MSCs may be a promising therapeutic method for the closure of bronchopleural fistula. Randomized controlled trials with larger samples are required.

Novel platinum agents and mesenchymal stromal cells for thoracic malignancies: state of the art and future perspectives

INTRODUCTION

Non-small cell lung cancer and malignant pleural mesothelioma represent two of the most intriguing and scrutinized thoracic malignancies, presenting interesting perspectives of experimental development and clinical applications.

AREAS COVERED

In advanced non-small cell lung cancer, molecular targeted therapy is the standard first-line treatment for patients with identified driver mutations; on the other hand, chemotherapy is the standard treatment for patients without EGFR mutations or ALK rearrangement or those with unknown mutation status. Once considered an ineffective therapy in pulmonary neoplasms, immunotherapy has been now established as one of the most promising therapeutic options. Mesenchymal stromal cells are able to migrate specifically toward solid neoplasms and their metastatic localizations when injected intravenously. This peculiar cancer tropism has opened up an emerging field to use them as vectors to deliver antineoplastic drugs for targeted therapies.

EXPERT OPINION

Molecular targeted therapy and immunotherapy are the new alternatives to standard chemotherapy. Mesenchymal stromal cells are a new promising tool in oncology and-although not yet utilized in the clinical practice, we think they will represent another main tool for cancer therapy and will probably play a leading role in the field of nanovectors and molecular medicine.

Chinese expert consensus on diagnosis and management of acquired respiratory-digestive tract fistulas

Acquired respiratory‐digestive tract fistulas occur with abnormal communication between the airways and digestive tract, causing the interflow of gas and liquid. Despite advances in surgical methods and the development of multimodal therapy in recent years, patients with acquired respiratory‐digestive tract fistulas continue to exhibit unfavorable clinical outcomes. Therefore, in order to guide clinical practice in China, the Respiratory and Cancer Intervention Alliance of the Beijing Health Promotion Association organized a group of experienced experts in the field to develop this consensus document. Based on a study of clinical application and expert experience in the diagnosis and management of acquired respiratory‐digestive tract fistulas at home and abroad, an Expert Consensus was developed. The panelists recruited comprised experts in pulmonology, oncology, thoracic surgery, interventional radiology, and gastroenterology. PubMed, Chinese Biology Abstract, Chinese Academic Journal, and Wanfang databases were used to identify relevant articles. The guidelines address etiology, classification, pathogenesis, diagnosis and management of acquired respiratory‐digestive tract fistulas. The statements on treatment focus on the indications for different procedures, technical aspects, and preprocedural, post‐procedural and complication management. The proposed guidelines for the diagnosis and management of acquired respiratory‐digestive tract fistulas are the first to be published by Chinese experts. These guidelines provide an in‐depth review of the current evidence and standard of diagnosis and management.

Artificial lung

Lung transplantation remains the definitive curative treatment for end-stage lung disease. However, future applications of tissue bioengineering could overcome the donor organ shortage and the need for immunosuppression. The final goal of lung tissue engineering is to recreate the whole spectrum of specialized lung tissues and thereby provide physiologic functions through bioengineered conducting airways, vasculature and gas exchange tissue. This review focuses on ongoing research in artificial lung development, open questions, achievements to date and how tissue engineering and stem cell technology may further contribute to the clinical application of bioartificial lungs. Although experimental transplantation of bioartificial lung developed by perfusing decellularized or synthetic scaffolds has been shown to provide gas exchange in vivo over a prolonged period, it should be clearly acknowledged that the development of a transplantable bioartificial lung is far from reality.

Long-term regeneration and remodeling of the pig esophagus after circumferential resection using a retrievable synthetic scaffold carrying autologous cells

Treatment of esophageal disease can necessitate resection and reconstruction of the esophagus. Current reconstruction approaches are limited to utilization of an autologous conduit such as stomach, small bowel, or colon. A tissue engineered construct providing an alternative for esophageal replacement in circumferential, full thickness resection would have significant clinical applications. In the current study, we demonstrate that regeneration of esophageal tissue is feasible and reproducible in a large animal model using synthetic polyurethane electro-spun grafts seeded with autologous adipose-derived mesenchymal stem cells (aMSCs) and a disposable bioreactor. The scaffolds were not incorporated into the regrown esophageal tissue and were retrieved endoscopically. Animals underwent adipose tissue biopsy to harvest and expand autologous aMSCs for seeding on electro-spun polyurethane conduits in a bioreactor. Anesthetized pigs underwent full thickness circumferential resection of the mid-lower thoracic esophagus followed by implantation of the cell seeded scaffold. Results from these animals showed gradual structural regrowth of endogenous esophageal tissue, including squamous esophageal mucosa, submucosa, and smooth muscle layers with blood vessel formation. Scaffolds carrying autologous adipose-derived mesenchymal stem cells may provide an alternative to the use of a gastro-intestinal conduit for some patients following resection of the esophagus.

Mesenchymal Stromal Cells for Antineoplastic Drug Loading and Delivery

Mesenchymal stromal cells are a population of undifferentiated multipotent adult cells possessing extensive self-renewal properties and the potential to differentiate into a variety of mesenchymal lineage cells. They express broad anti-inflammatory and immunomodulatory activity on the immune system and after transplantation can interact with the surrounding microenvironment, promoting tissue healing and regeneration. For this reason, mesenchymal stromal cells have been widely used in regenerative medicine, both in preclinical and clinical settings. Another clinical application of mesenchymal stromal cells is the targeted delivery of chemotherapeutic agents to neoplastic cells, maximizing the cytotoxic activity against cancer cells and minimizing collateral damage to non-neoplastic tissues. Mesenchymal stem cells are home to the stroma of several primary and metastatic neoplasms and hence can be used as vectors for targeted delivery of antineoplastic drugs to the tumour microenvironment, thereby reducing systemic toxicity and maximizing antitumour effects. Paclitaxel and gemcitabine are the chemotherapeutic drugs best loaded by mesenchymal stromal cells and delivered to neoplastic cells, whereas other agents, like pemetrexed, are not internalized by mesenchymal stromal cells and therefore are not suitable for advanced antineoplastic therapy. This review focuses on the state of the art of advanced antineoplastic cell therapy and its future perspectives, emphasizing in vitro and in vivo preclinical results and future clinical applications.

Transplanted fibroblasts proliferate in host bronchial tissue and enhance bronchial anastomotic healing in a rodent model

INTRODUCTION

Healing of airway anastomoses after preoperative irradiation can be a significant clinical problem. The augmentation of bronchial anastomoses with a fibroblast-seeded human acellular dermis (hAD) was shown to be beneficial, although the underlying mechanism remained unclear. Therefore, in this study we investigated the fate of the fibroblasts transplanted to the scaffold covering the anastomosis.

MATERIAL AND METHODS

32 Fisher rats underwent surgical anastomosis of the left main bronchus. In a 2 × 2 factorial design, they were randomized to receive preoperative irradiation of 20 Gy and augmentation of the anastomosis with a fibroblast-seeded transplant. Fibroblasts from subcutaneous fat of Fischer-344 rat were transduced retrovirally with tdTomato for cell tracking. After 7 and 14 days, animals were sacrificed and cell concentration of transplanted and nontransplanted fibroblasts in the hAD as well as in the bronchial tissue was measured using RT-PCR.

RESULTS

Migration of transplanted fibroblasts from dermis to bronchus were demonstrated in both groups, irradiated and nonirradiated. In the irradiated groups, there was a cell count of 7 × 104 ± 1 × 104 tomato+-fibroblasts in the bronchial tissue at day 7, rising to 1 × 105 ± 1 × 104 on day 14 (p <0.0001). Tomato+-cell concentration in hAD increased from 6 × 103 ± 1 × 103 at day 7 to 6 × 104 ± 1 × 104 at day 14 (p <0.0001). In the nonirradiated groups, tomato+-cell concentration in bronchus was 4 × 103 ± 1 × 103 on day 7 and 4 × 103 ± 1 × 103 at day 14. In the hAD tomato+ cell concentration rising from 1 × 104 ± 1 × 103 at day 7 to 2 × 104 ± 3 × 103 cells at day 14 (p = 0.0028).

CONCLUSIONS

Transplanted fibroblasts in the irradiated groups proliferate and migrate into the irradiated host bronchial tissue, but not in the nonirradiated groups.

In vitro labelling and detection of mesenchymal stromal cells: a comparison between magnetic resonance imaging of iron-labelled cells and magnetic resonance spectroscopy of fluorine-labelled cells

Background

Among the various stem cell populations used for cell therapy, adult mesenchymal stromal cells (MSCs) have emerged as a major new cell technology. These cells must be tracked after transplantation to monitor their migration within the body and quantify their accumulation at the target site. This study assessed whether rat bone marrow MSCs can be labelled with superparamagnetic iron oxide (SPIO) nanoparticles and perfluorocarbon (PFC) nanoemulsion formulations without altering cell viability and compared magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) results from iron-labelled and fluorine-labelled MSCs, respectively.

Methods

Of MSCs, 2 × 10⁶ were labelled with Molday ION Rhodamine-B (MIRB) and 2 × 10⁶ were labelled with Cell Sense. Cell viability was evaluated by trypan blue exclusion method. Labelled MSCs were divided into four samples containing increasing cell numbers (0.125 × 10⁶, 0.25 × 10⁶, 0.5 × 10⁶, 1 × 10⁶) and scanned on a 7T MRI: for MIRB-labelled cells, phantoms and cells negative control, T1, T2 and T2* maps were acquired; for Cell Sense labelled cells, phantoms and unlabelled cells, a ¹⁹F non-localised single-pulse MRS sequence was acquired.

Results

In total, 86.8% and 83.6% of MIRB-labelled cells and Cell Sense-labelled cells were viable, respectively. MIRB-labelled cells were visible in all samples with different cell numbers; pellets containing 0.5 × 10⁶ and 1 × 10⁶ of Cell Sense-labelled cells showed a detectable ¹⁹F signal.

Conclusions

Our data support the use of both types of contrast material (SPIO and PFC) for MSCs labelling, although further efforts should be dedicated to improve the efficiency of PFC labelling.

A systematic review and meta-analysis-does chronic obstructive pulmonary disease predispose to bronchopleural fistula formation in patients undergoing lung cancer surgery?

BACKGROUND

we conducted this systematic meta-analysis to determine the association between chronic obstructive pulmonary disease (COPD) and risk of bronchopleural fistula (BPF) in patients undergoing lung cancer surgery.

METHODS

Literature retrieval was performed in PubMed, Embase and the Web of Science to identify the full-text articles that met our eligibility criteria. Odds ratio (OR) with 95% confidence interval (CI) served as the summarized statistics. Q-test and I(2)-statistic were used to evaluate the level of heterogeneity. Sensitivity analysis was performed to further examine the stability of pooled OR. Publication bias was detected by both Begg's test and Egger's test.

RESULTS

Eight retrospective observational studies were included into this meta-analysis. The overall summarized OR was 2.03 (95% CI: 1.44-2.86; P<0.001), revealing that COPD was significantly associated with the risk of BPF after lung cancer surgery. In subgroup analysis, the relationship between COPD and BPF occurrence remained statistically prominent in the subgroups stratified by statistical analysis (univariate analysis, OR: 1.91; 95% CI: 1.35-2.69; P<0.001; multivariate analysis, OR: 3.18; 95% CI: 1.95-5.19; P<0.001), operative modes (pneumonectomy, OR: 2.11; 95% CI: 1.15-3.87; P=0.016) and in non-Asian populations (OR: 2.36; 95% CI: 1.18-4.73; P=0.016). No significant impact of COPD on BPF risk was observed in Asian patients (OR: 1.48; 95% CI: 0.85-2.57; P=0.16). No significant heterogeneity or publication bias was discovered across the included studies.

CONCLUSIONS

Our meta-analysis indicates that COPD can significantly predispose to BPF formation in patients undergoing lung cancer surgery. Because some limitations still exist in this meta-analysis, our findings should be further verified and modified in the future.

Closure of a Recurrent Bronchopleural Fistula Using a Matrix Seeded With Patient-Derived Mesenchymal Stem Cells

This is the first-in-human application of an autologous mesenchymal stem cell (MSC)-seeded matrix graft to repair a multiply recurrent postpneumonectomy bronchopleural fistula (BPF). Adipose-derived MSCs were isolated from patient abdominal adipose tissue, expanded, and seeded onto bio-absorbable mesh, which was surgically implanted at the BPF site. After clinical follow-up of 1.5 years, the patient is clinically asymptomatic without evidence of recurrence or malignant degeneration of MSC populations in situ.

Management of recurrent bronchopleural fistula (BPF) after pneumonectomy remains a challenge. Although a variety of devices and techniques have been described, definitive management usually involves closure of the fistula tract through surgical intervention. Standard surgical approaches for BPF incur significant morbidity and mortality and are not reliably or uniformly successful. We describe the first-in-human application of an autologous mesenchymal stem cell (MSC)-seeded matrix graft to repair a multiply recurrent postpneumonectomy BPF. Adipose-derived MSCs were isolated from patient abdominal adipose tissue, expanded, and seeded onto bio-absorbable mesh, which was surgically implanted at the site of BPF. Clinical follow-up and postprocedural radiological and bronchoscopic imaging were performed to ensure BPF closure, and in vitro stemness characterization of patient-specific MSCs was performed. The patient remained clinically asymptomatic without evidence of recurrence on bronchoscopy at 3 months, computed tomographic imaging at 16 months, and clinical follow-up of 1.5 years. There is no evidence of malignant degeneration of MSC populations in situ, and the patient-derived MSCs were capable of differentiating into adipocytes, chondrocytes, and osteocytes using established protocols. Isolation and expansion of autologous MSCs derived from patients in a malnourished, deconditioned state is possible. Successful closure and safety data for this approach suggest the potential for an expanded study of the role of autologous MSCs in regenerative surgical applications for BPF.

Significance

Bronchopleural fistula is a severe complication of pulmonary resection. Current management is not reliably successful. This work describes the first-in-human application of an autologous mesenchymal stem cell (MSC)-seeded matrix graft to the repair of a large, multiply recurrent postpneumonectomy BPF. Clinical follow-up of 1.5 years without recurrence suggests initial safety and feasibility of this approach. Further assessment of MSC grafts in these difficult clinical scenarios requires expanded study.

Current Perspectives in Mesenchymal Stromal Cell Therapies for Airway Tissue Defects

Lung cancer is the leading cause of cancer death and respiratory diseases are the third cause of death in industrialized countries; for this reason the airways and cardiopulmonary system have been the focus of extensive investigation, in particular of the new emerging branch of regenerative medicine. Mesenchymal stromal cells (MSCs) are a population of undifferentiated multipotent adult cells that naturally reside within the human body, which can differentiate into osteogenic, chondrogenic, and adipogenic lineages when cultured in specific inducing media. MSCs have the ability to migrate and engraft at sites of inflammation and injury in response to cytokines, chemokines, and growth factors at a wound site and they can exert local reparative effects through transdifferentiation and differentiation into specific cell types or via the paracrine secretion of soluble factors with anti-inflammatory and wound-healing activities. Experimental and clinical evidence exists regarding MSCs efficacy in airway defects restoration; although clinical MSCs use, in the daily practice, is not yet completely reached for airway diseases, we can argue that MSCs do not represent any more merely an experimental approach to airway tissue defects restoration but they can be considered as a “salvage” therapeutic tool in very selected patients and diseases.