Personalized Cancer Medicine: An Organoid Approach

Personalized cancer therapy applies specific treatments to each patient. Using personalized tumor models with similar characteristics to the original tumors may result in more accurate predictions of drug responses in patients. Tumor organoid models have several advantages over pre-existing models, including conserving the molecular and cellular composition of the original tumor. These advantages highlight the tremendous potential of tumor organoids in personalized cancer therapy, particularly preclinical drug screening and predicting patient responses to selected treatment regimens. Here, we highlight the advantages, challenges, and translational potential of tumor organoids in personalized cancer therapy and focus on gene-drug associations, drug response prediction, and treatment selection. Finally, we discuss how microfluidic technology can contribute to immunotherapy drug screening in tumor organoids.

Mesenchymal stem cells derived from perinatal tissues for treatment of critically ill COVID-19-induced ARDS patients: a case series

Background

Acute respiratory distress syndrome (ARDS) is a fatal complication of coronavirus disease 2019 (COVID-19). There are a few reports of allogeneic human mesenchymal stem cells (MSCs) as a potential treatment for ARDS. In this phase 1 clinical trial, we present the safety, feasibility, and tolerability of the multiple infusions of high dose MSCs, which originated from the placenta and umbilical cord, in critically ill COVID-19-induced ARDS patients.

Methods

A total of 11 patients diagnosed with COVID-19-induced ARDS who were admitted to the intensive care units (ICUs) of two hospitals enrolled in this study. The patients were critically ill with severe hypoxemia and required mechanical ventilation. The patients received three intravenous infusions (200 × 10⁶ cells) every other day for a total of 600 × 10⁶ human umbilical cord MSCs (UC-MSCs; 6 cases) or placental MSCs (PL-MSCs; 5 cases).

Findings

There were eight men and three women who were 42 to 66 years of age. Of these, six (55%) patients had comorbidities of diabetes, hypertension, chronic lymphocytic leukemia (CLL), and cardiomyopathy (CMP). There were no serious adverse events reported 24–48 h after the cell infusions. We observed reduced dyspnea and increased SpO2 within 48–96 h after the first infusion in seven patients. Of these seven patients, five were discharged from the ICU within 2–7 days (average: 4 days), one patient who had signs of acute renal and hepatic failure was discharged from the ICU on day 18, and the last patient suddenly developed cardiac arrest on day 7 of the cell infusion. Significant reductions in serum levels of tumor necrosis factor-alpha (TNF-α; P < 0.01), IL-8 (P < 0.05), and C-reactive protein (CRP) (P < 0.01) were seen in all six survivors. IL-6 levels decreased in five (P = 0.06) patients and interferon gamma (IFN-γ) levels decreased in four (P = 0.14) patients. Four patients who had signs of multi-organ failure or sepsis died in 5–19 days (average: 10 days) after the first MSC infusion. A low percentage of lymphocytes (< 10%) and leukocytosis were associated with poor outcome (P = 0.02). All six survivors were well with no complaints of dyspnea on day 60 post-infusion. Radiological parameters of the lung computed tomography (CT) scans showed remarkable signs of recovery.

Interpretation

We suggest that multiple infusions of high dose allogeneic prenatal MSCs are safe and can rapidly improve respiratory distress and reduce inflammatory biomarkers in some critically ill COVID-19-induced ARDS cases. Patients that develop sepsis or multi-organ failure may not be good candidates for stem cell therapy. Large randomized multicenter clinical trials are needed to discern the exact therapeutic potentials of MSC in COVID-19-induced ARDS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02165-4.

Three-dimensional liver-derived extracellular matrix hydrogel promotes liver organoids function

An important advantage of employing extracellular matrix (ECM)-derived biomaterials in tissue engineering is the ability to tailor the biochemical and biophysical microenvironment of the cells. This study aims to assess whether three-dimensional (3D) liver-derived ECM hydrogel (LEMgel) promotes physiological function of liver organoids generated by self-organization of human hepatocarcinoma cells together with human mesenchymal and endothelial cells. We have optimized the decellularization method to fabricate liver ECM derived from sheep to preserve the greatest content of glycosaminoglycans, collagen, laminin, and fibronectin in produced LEMgel. During gelation, complex viscoelasticity modulus of the LEMgel (3 mg/mL) increased from 186.7 to 1570.5 Pa and Tan Delta decreased from 0.27 to 0.18. Scanning electron microscopy (SEM) determined that the LEMgel had a pore size of 382 ± 71 µm. Hepatocarcinoma cells in the self-organized liver organoids in 3D LEMgel (LEMgel organoids) showed an epithelial phenotype and expressed ALB, CYP3A4, E-cadherin, and ASGPR. The LEMgel organoid had significant upregulation of transcripts of ALB, CYP3A4, CYP3A7, and TAT as well as downregulation of AFP compared to collagen type I- and hydrogel-free-organoids or organoids in solubilized LEM and 2D culture of hepatocarcinoma cells. Generated 3D LEMgel organoids had significantly more ALB and AAT secretion, urea production, CYP3A4 enzyme activity, and inducibility. In conclusion, 3D LEMgel enhanced the functional activity of self-organized liver organoids compared to traditional 2D, 3D, and collagen gel cultures. Our novel 3D LEMgel organoid could potentially be used in liver tissue engineering, drug discovery, toxicology studies, or bio-artificial liver fabrication.

Generation of functional hepatocyte-like cells from human pluripotent stem cells in a scalable suspension culture

Recent advances in human embryonic and induced pluripotent stem cell-based therapies in animal models of hepatic failure have led to an increased appreciation of the need to translate the proof-of-principle concepts into more practical and feasible protocols for scale up and manufacturing of functional hepatocytes. In this study, we describe a scalable stirred-suspension bioreactor culture of functional hepatocyte-like cells (HLCs) from the human pluripotent stem cells (hPSCs). To promote the initial differentiation of hPSCs in a carrier-free suspension stirred bioreactor into definitive endoderm, we used rapamycin for "priming" phase and activin A for induction. The cells were further differentiated into HLCs in the same system. HLCs were characterized and then purified based on their physiological function, the uptake of DiI-acetylated low-density lipoprotein (LDL) by flow cytometry without genetic manipulation or antibody labeling. The sorted cells were transplanted into the spleens of mice with acute liver injury from carbon tetrachloride. The differentiated HLCs had multiple features of primary hepatocytes, for example, the expression patterns of liver-specific marker genes, albumin secretion, urea production, collagen synthesis, indocyanin green and LDL uptake, glycogen storage, and inducible cytochrome P450 activity. They increased the survival rate, engrafted successfully into the liver, and continued to present hepatic function (i.e., albumin secretion after implantation). This amenable scaling up and outlined enrichment strategy provides a new platform for generating functional HLCs. This integrated approach may facilitate biomedical applications of the hPSC-derived hepatocytes.

Clinical hepatocyte transplantation: practical limits and possible solutions

Since the first human hepatocyte transplants (HTx) in 1992, clinical studies have clearly established proof of principle for this therapy as a treatment for patients with acquired or inherited liver disease. Although major accomplishments have been made, there are still some specific limitations to this technology, which, if overcome, could greatly enhance the efficacy and implementation of this therapy. Here, we describe what in our view are the most significant obstacles to the clinical application of HTx and review the solutions currently proposed. The obstacles of significance include the limited number and quality of liver tissues as a cell source, the lack of clinical grade reagents, quality control evaluation of hepatocytes prior to transplantation, hypothermic storage of cells prior to transplantation, preconditioning treatments to enhance engraftment and proliferation of donor cells, tracking or monitoring cells after transplantation, and the optimal immunosuppression protocols for transplant recipients.

Circular RNAs: New Epigenetic Signatures in Viral Infections

Covalent closed circular RNAs (circRNAs) can act as a bridge between non-coding RNAs and coding messenger RNAs. CircRNAs are generated by a back-splicing mechanism during post-transcriptional processing and are abundantly expressed in eukaryotic cells. CircRNAs can act via the modulation of RNA transcription and protein production, and by the sponging of microRNAs (miRNAs). CircRNAs are now thought to be involved in many different biological and pathological processes. Some studies have suggested that the expression of host circRNAs is dysregulated in several types of virus-infected cells, compared to control cells. It is highly likely that viruses can use these molecules for their own purposes. In addition, some viral genes are able to produce viral circRNAs (VcircRNA) by a back-splicing mechanism. However, the viral genes that encode VcircRNAs, and their functions, are poorly studied. In this review, we highlight some new findings about the interaction of host circRNAs and viral infection. Moreover, the potential of VcircRNAs derived from the virus itself, to act as biomarkers and therapeutic targets is summarized.

Tissue Engineering in Liver Regenerative Medicine: Insights into Novel Translational Technologies

Organ and tissue shortage are known as a crucially important public health problem as unfortunately a small percentage of patients receive transplants. In the context of emerging regenerative medicine, researchers are trying to regenerate and replace different organs and tissues such as the liver, heart, skin, and kidney. Liver tissue engineering (TE) enables us to reproduce and restore liver functions, fully or partially, which could be used in the treatment of acute or chronic liver disorders and/or generate an appropriate functional organ which can be transplanted or employed as an extracorporeal device. In this regard, a variety of techniques (e.g., fabrication technologies, cell-based technologies, microfluidic systems and, extracorporeal liver devices) could be applied in tissue engineering in liver regenerative medicine. Common TE techniques are based on allocating stem cell-derived hepatocyte-like cells or primary hepatocytes within a three-dimensional structure which leads to the improvement of their survival rate and functional phenotype. Taken together, new findings indicated that developing liver tissue engineering-based techniques could pave the way for better treatment of liver-related disorders. Herein, we summarized novel technologies used in liver regenerative medicine and their future applications in clinical settings.

Microfluidics for detection of exosomes and microRNAs in cancer: State of the art

Exosomes are small extracellular vesicles with sizes ranging from 30-150 nanometers that contain proteins, lipids, mRNAs, microRNAs, and double-stranded DNA derived from the cells of origin. Exosomes can be taken up by target cells, acting as a means of cell-to-cell communication. The discovery of these vesicles in body fluids and their participation in cell communication has led to major breakthroughs in diagnosis, prognosis, and treatment of several conditions (e.g., cancer). However, conventional isolation and evaluation of exosomes and their microRNA content suffers from high cost, lengthy processes, difficult standardization, low purity, and poor yield. The emergence of microfluidics devices with increased efficiency in sieving, trapping, and immunological separation of small volumes could provide improved detection and monitoring of exosomes involved in cancer. Microfluidics techniques hold promise for advances in development of diagnostic and prognostic devices. This review covers ongoing research on microfluidics devices for detection of microRNAs and exosomes as biomarkers and their translation to point-of-care and clinical applications.

Stem cell therapy in Alzheimer's disease: possible benefits and limiting drawbacks

Alzheimer's disease (AD) is the sixth leading cause of death globally and the main reason for dementia in elderly people. AD is a long-term and progressive neurodegenerative disorder that steadily worsens memory and communicating skills eventually leads to a disabled person of performing simple daily tasks. Unfortunately, numerous clinical trials exploring new therapeutic drugs have encountered disappointing outcomes in terms of improved cognitive performance since they are not capable of halting or stimulating the regeneration of already-damaged neural cells, and merely provide symptomatic relief. Therefore, a deeper understanding of the mechanism of action of stem cell may contribute to the development of novel and effective therapies. The revolutionary discovery of stem cells has cast a new hope for the development of disease-modifying treatments for AD, in terms of their potency in the replenishment of lost cells via differentiating towards specific lineages, stimulating in situ neurogenesis, and delivering the therapeutic agents to the brain. Herein, firstly, we explore the pathophysiology of AD. Next, we summarize the most recent preclinical stem cell reports designed for AD treatment, their benefits and outcomes according to cell type. We briefly review relevant clinical trials and their potential clinical applications in order to find a unique solution to effectively relieve the patients' pain.

Oxygen releasing materials: Towards addressing the hypoxia-related issues in tissue engineering

Manufacturing macroscale cell-laden architectures is one of the biggest challenges faced nowadays in the domain of tissue engineering. Such living constructs, in fact, pose strict requirements for nutrients and oxygen supply that can hardly be addressed through simple diffusion in vitro or without a functional vasculature in vivo. In this context, in the last two decades, a substantial amount of work has been carried out to develop smart materials that could actively provide oxygen-release to contrast local hypoxia in large-size constructs. This review provides an overview of the currently available oxygen-releasing materials and their synthesis and mechanism of action, highlighting their capacities under in vitro tissue cultures and in vivo contexts. Additionally, we also showcase an emerging concept, herein termed as "living materials as releasing systems", which relies on the combination of biomaterials with photosynthetic microorganisms, namely algae, in an "unconventional" attempt to supply the damaged or re-growing tissue with the necessary supply of oxygen. We envision that future advances focusing on tissue microenvironment regulated oxygen-supplying materials would unlock an untapped potential for generating a repertoire of anatomic scale, living constructs with improved cell survival, guided differentiation, and tissue-specific biofunctionality.

Critical signaling pathways governing hepatocellular carcinoma behavior; small molecule-based approaches

Hepatocellular carcinoma (HCC) is the second leading cause of death due to cancer. Although there are different treatment options, these strategies are not efficient in terms of restricting the tumor cell's proliferation and metastasis. The liver tumor microenvironment contains the non-parenchymal cells with supportive or inhibitory effects on the cancerous phenotype of HCC. Several signaling pathways are dis-regulated in HCC and cause uncontrolled cell propagation, metastasis, and recurrence of liver carcinoma cells. Recent studies have established new approaches for the prevention and treatment of HCC using small molecules. Small molecules are compounds with a low molecular weight that usually inhibit the specific targets in signal transduction pathways. These components can induce cell cycle arrest, apoptosis, block metastasis, and tumor growth. Devising strategies for simultaneously targeting HCC and the non-parenchymal population of the tumor could lead to more relevant research outcomes. These strategies may open new avenues for the treatment of HCC with minimal cytotoxic effects on healthy cells. This study provides the latest findings on critical signaling pathways governing HCC behavior and using small molecules in the control of HCC both in vitro and in vivo models.

Autophagy and gastrointestinal cancers: the behind the scenes role of long non-coding RNAs in initiation, progression, and treatment resistance

Gastrointestinal (GI) cancers comprise a heterogeneous group of complex disorders that affect different organs, including esophagus, stomach, gallbladder, liver, biliary tract, pancreas, small intestine, colon, rectum, and anus. Recently, an explosion in nucleic acid-based technologies has led to the discovery of long non-coding RNAs (lncRNAs) that have been found to possess unique regulatory functions. This class of RNAs is >200 nucleotides in length, and is characterized by their lack of protein coding. LncRNAs exert regulatory effects in GI cancer development by affecting different functions such as the proliferation and metastasis of cancer cells, apoptosis, glycolysis and angiogenesis. Over the past few decades, considerable evidence has revealed the important role of autophagy in both GI cancer progression and suppression. In addition, recent studies have confirmed a significant correlation between lncRNAs and the regulation of autophagy. In this review, we summarize how lncRNAs play a behind the scenes role in the pathogenesis of GI cancers through regulation of autophagy.

Organoids: a novel modality in disease modeling

Limitations of monolayer culture conditions have motivated scientists to explore new models that can recapitulate the architecture and function of human organs more accurately. Recent advances in the improvement of protocols have resulted in establishing three-dimensional (3D) organ-like architectures called ‘organoids’ that can display the characteristics of their corresponding real organs, including morphological features, functional activities, and personalized responses to specific pathogens. We discuss different organoid-based 3D models herein, which are classified based on their original germinal layer. Studies of organoids simulating the complexity of real tissues could provide novel platforms and opportunities for generating practical knowledge along with preclinical studies, including drug screening, toxicology, and molecular pathophysiology of diseases. This paper also outlines the key challenges, advantages, and prospects of current organoid systems.

Intraportal Infusion of Bone Marrow Mononuclear or CD133+ Cells in Patients With Decompensated Cirrhosis: A Double-Blind Randomized Controlled Trial

The present study assessed the effects of intraportal infusions of autologous bone marrow-derived mononuclear cells (MNCs) and/or CD133+ cells on liver function in patients with decompensated cirrhosis. We randomly assigned 27 eligible patients to a placebo, MNCs, and/or CD133+ cells. Cell infusions were performed at baseline and month 3. We considered the absolute changes in the Model for End-Stage Liver Disease (MELD) scores at months 3 and 6 after infusion as the primary outcome. The participants and those who assessed the outcomes were unaware of the treatment intervention assignments. After 6 months, 9 patients were excluded because of liver transplantation (n=3), hepatocellular carcinoma (n=1), loss to follow-up (n=3), and death (n=2). The final analysis included 4 patients from the CD133+ group, 8 from the MNC group, and 6 from the placebo group. No improvement was seen in the MELD score at month 6 using either CD133+ cells or MNC infusions compared with placebo. However, at month 3 after infusion, a trend was seen toward a higher mean absolute change in the MELD score in patients who had received CD133+ cells compared with placebo (-2.00±1.87 vs. -0.13±1.46; p=.08). No significant adverse events occurred in the present study. A transient improvement in the MELD score was observed in subjects treated with CD133+ cells but not in the MNC or placebo group. Although the study was not powered to make definitive conclusions, the data justify further study of CD133+ therapy in cirrhotic patients.

SIGNIFICANCE

Cell therapy is a new approach in liver disease. Several clinical experiments have been reported on the safety of bone marrow-derived stem cells to treat liver disorders. However, the effectiveness of these approaches in the long-term follow-ups of patients initiated controversial discussions among the scientific community. A double-blind randomized controlled trial was designed to address this concern scientifically. A transient improvement in the patients' signs occurred; however, for a sustainable result, more work is needed. The results of multiple administrations of cells reported in the present study can be compared with the results from other single-injection studies.

Rapid and sensitive assessment of human hepatocyte functions

Transplantation of human hepatocytes (HTx) has gained recognition as a bridge to, or an alternative to, orthotopic liver transplantation for patients with acute liver failure or genetic defects in liver function. Although the quality of the hepatocytes used for cell transplantation is critical, no consensus exists on protocols to assess the function of hepatocytes prior to HTx. Application of this cell therapy in clinical practice could be aided by fast and reliable assays to evaluate the functional competence of isolated hepatocytes prior to clinical transplantation. Traditional assays for measuring metabolic functions in primary hepatocytes frequently involve highly technical equipment, time-consuming methods, and large numbers of cells. We describe a novel approach for the rapid assessment of the metabolic capabilities of human hepatocytes. This report details simple procedures to evaluate 11 endpoints from cells isolated from human liver that can be performed by a single operator within approximately 2 h of isolation. Longer term cultured hepatocytes were also analyzed to determine if the results from the 2-h tests were predictive of long-term hepatic function. The assays simultaneously measure five cytochrome P450 activities, one phase II activity, plating efficiency, and ammonia metabolism in addition to viability and cell yield. The assays require fewer than 20 million cells and can be completed using commonly available and inexpensive laboratory equipment. The protocol details methods that can be used in a time frame that would allow analysis of hepatic functions in freshly isolated hepatocytes prior to their use for clinical transplantation.

Guide to the Assessment of Mature Liver Gene Expression in Stem Cell-Derived Hepatocytes

Differentiation of stem cells to hepatocyte-like cells (HLCs) holds great promise for basic research, drug and toxicological investigations, and clinical applications. There are currently no protocols for the production of HLCs from stem cells, such as embryonic stem cells or induced pluripotent stem cells, that produce fully mature hepatocytes with a wide range of mature hepatic functions. This report describes a standard method to assess the maturation of stem cell-derived HLCs with a moderately high-throughput format, by analysing liver gene expression by quantitative RT-qPCR. This method also provides a robust data set of the expression of 62 genes expressed in normal liver, generated from 17 fetal and 25 mature human livers, so that investigators can quickly and easily compare the expression of these genes in their stem cell-derived HLCs with the values obtained in authentic fetal and mature human liver. The simple methods described in this study will provide a quick and accurate assessment of the efficacy of a differentiation protocol and will help guide the optimization of differentiation conditions.

Towards improved hepatocyte cultures: Progress and limitations

Hepatotoxicity is among the most frequent reasons for drug withdrawal from the market. Therefore, there is an urgent need for reliable predictive in vitro tests, which unfailingly identify hepatotoxic drug candidates, reduce drug development time, expenses and the number of test animals. Currently, human hepatocytes represent the gold standard. However, the use of hepatocytes is challenging since the cells are not constantly available and lose their metabolic activity in culture. To solve these problems many different approaches have been developed in the past decades. The aim of this review is to present these approaches and to discuss the possibilities and limitations as well as future opportunities and directions.

Cell-based therapeutics for liver disorders

INTRODUCTION

Due to a lack of adequate liver donors and post-surgical complications, researchers propose that cell therapy should be an alternative treatment for patients with end-stage liver diseases.

DATA SOURCES

We performed a literature review on cell-based therapy for liver disorders.

AREAS OF AGREEMENT

Due to growing numbers of patients on waiting lists for liver transplantation, a substitute treatment strategy is needed for our patients. Cell therapy can save patients who are in life-threatening situations, enabling them to have more time and increase their chances of survival. Pluripotent stem cells can be a good resource for cell-based therapy after the establishment of efficient differentiation protocols in addition to the settlement of ethical and immunological issues. Cell-based therapy will be applicable after the approval of its efficiency via animal model studies.

AREAS OF CONTROVERSY

Transplanted cells cannot integrate into the recipient liver and lose their functionality after a limited time. The rate of homing and transdifferentiation of transplanted cells into hepatocytes is scant.

GROWING POINTS

Application of autologous bone marrow mononuclear cells (MNCs), hematopoietic and mesenchymal stem cells (HSCs and MSCs) has improved the general conditions of certain patients. Although this improvement is temporary, new studies have focused on increasing their performance. TIMELY AREAS FOR DEVELOPING RESEARCH: The safety, feasibility and efficacy of applying MNCs, HSCs and MSCs in liver disorders have been proven in clinical trials. Patient-specific cell therapy after the production of induced pluripotent stem cells and new discoveries in somatic cell conversion during transdifferentiation are promising insights.

Allogenic mesenchymal stromal cells and their extracellular vesicles in COVID-19 induced ARDS: a randomized controlled trial

BACKGROUND AND AIMS

The main causes of death in patients with severe Coronavirus disease-2019 (COVID-19) are acute respiratory distress syndrome (ARDS) and multiorgan failure caused by a severe inflammatory cascade. Novel treatment strategies, such as stem-cell-based therapy and their derivatives can be used to relieve inflammation in these cases. In this study, we aimed to evaluate the safety and efficacy of therapy using mesenchymal stromal cells (MSCs) and their derived extracellular vesicles in COVID-19 patients.

MATERIALS AND METHODS

COVID-19 patients with ARDS were included in this study and allocated into two study and control groups using block randomization. While all patients received recommended treatment based on guidelines from the national advisory committee for COVID-19 pandemic, the two intervention groups received two consecutive injections of MSCs (100 × 106 cells) or one dose of MSCs (100 × 106 cells) followed by one dose of MSC-derived extracellular vesicles (EVs). Patients were assessed for safety and efficacy by evaluating clinical symptoms, laboratory parameters, and inflammatory markers at baseline and 48 h after the second intervention.

RESULTS

A total number of 43 patients (the MSC alone group = 11, MSC plus EV group = 8, and control group = 24) were included in the final analysis. Mortality was reported in three patients in the MSC alone group (RR: 0.49; 95% CI 0.14-1.11; P = 0.08); zero patient in the MSC plus EV group (RR: 0.08; 95% CI 0.005-1.26; P = 0.07) and eight patients in the control group. MSC infusion was associated with a decrease in inflammatory cytokines such as IL-6 (P = 0.015), TNF-α (P = 0.034), IFN-γ (P = 0.024), and CRP (P = 0.041).

CONCLUSION

MSCs and their extracellular vesicles can significantly reduce the serum levels of inflammatory markers in COVID-19 patients, with no serious adverse events. Trial registration IRCT, IRCT registration number: IRCT20200217046526N2. Registered 13th April 2020, http://www.irct.ir/trial/47073 .

Novel therapeutic approaches for treatment of COVID-19

To date, there is no licensed treatment or approved vaccine to combat the coronavirus disease of 2019 (COVID-19), and the number of new cases and mortality multiplies every day. Therefore, it is essential to develop an effective treatment strategy to control the virus spread and prevent the disease. Here, we summarized the therapeutic approaches that are used to treat this infection. Although it seems that antiviral drugs are effective in improving clinical manifestation, there is no definite treatment protocol. Lymphocytopenia, excessive inflammation, and cytokine storm followed by acute respiratory distress syndrome are still unsolved issues causing the severity of this disease. Therefore, immune response modulation and inflammation management can be considered as an essential step. There is no doubt that more studies are required to clarify immunopathogenesis and immune response; however, new therapeutic approaches including mesenchymal stromal cell and immune cell therapy showed inspiring results.

Engineering a Model to Study Viral Infections: Bioprinting, Microfluidics, and Organoids to Defeat Coronavirus Disease 2019 (COVID-19)

While the number of studies related to severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) is constantly growing, it is essential to provide a framework of modeling viral infections. Therefore, this review aims to describe the background presented by earlier used models for viral studies and an approach to design an "ideal" tissue model for SARS-CoV-2 infection. Due to the previous successful achievements in antiviral research and tissue engineering, combining the emerging techniques such as bioprinting, microfluidics, and organoid formation are considered to be one of the best approaches to form in vitro tissue models. The fabrication of an integrated multi-tissue bioprinted platform tailored for SARS-CoV-2 infection can be a great breakthrough that can help defeat coronavirus disease in 2019.