Enhancing bone regeneration: Unleashing the potential of magnetic nanoparticles in a microtissue model.

Bone tissue engineering addresses the limitations of autologous resources and the risk of allograft disease transmission in bone diseases. In this regard, engineered three-dimensional (3D) models emerge as biomimetic alternatives to natural tissues, replicating intracellular communication. Moreover, the unique properties of super-paramagnetic iron oxide nanoparticles (SPIONs) were shown to promote bone regeneration via enhanced osteogenesis and angiogenesis in bone models. This study aimed to investigate the effects of SPION on both osteogenesis and angiogenesis and characterized a co-culture of Human umbilical vein endothelial cells (HUVEC) and MG-63 cells as a model of bone microtissue. HUVECs: MG-63s with a ratio of 4:1 demonstrated the best results among other cell ratios, and 50 µg/mL of SPION was the optimum concentration for maximum survival, cell migration and mineralization. In addition, the data from gene expression illustrated that the expression of osteogenesis-related genes, including osteopontin, osteocalcin, alkaline phosphatase, and collagen-I, as well as the expression of the angiogenesis-related marker, CD-31, and the tube formation, is significantly elevated when the 50 µg/mL concentration of SPION is applied to the microtissue samples. SPION application in a designed 3D bone microtissue model involving a co-culture of osteoblast and endothelial cells resulted in increased expression of specific markers related to angiogenesis and osteogenesis. This includes the design of a novel biomimetic model to boost blood compatibility and biocompatibility of primary materials while promoting osteogenic activity in microtissue bone models. Moreover, this can improve interaction with surrounding tissues and broaden the knowledge to promote superior-performance implants, preventing device failure.

Trinitroglycerin-loaded chitosan nanogels accelerate angiogenesis in wound healing process.

Trinitroglycerin (TNG) with remarkable angiogenic, antibacterial, and antioxidative activity is a promising candidate to govern wound healing capacity. However, its clinical administration is limited due to associated complications and NO short half-life. In the current study, TNG-loaded chitosan nanogels (TNG-Ngs) were examined in-vitro and in-vivo to gain insight into their clinical application. We prepared TNG-Ngs and characterized their physiochemical properties. The potential of TNG-Ngs was assessed using biocompatibility, scratch assay, and a full-thickness skin wounds model, followed by histopathological and immunohistochemistry examinations. TNG-Ngs particle size 96 ± 18 and definite size distribution histogram. The loading capacity (LC) and encapsulation efficiency (EE) of prepared TNG-Ngs were 70.2 % and 2.1 %, respectively. The TNG-Ngs samples showed enhanced migration of HUVECs with no apparent cytotoxicity. The topical use of TNG-Ngs200 on the wounds revealed a complete wound closure ratio, skin component formation, less scar width, remarkable granulation tissue, promoted collagen deposition, and enhanced the relative mean density of α-SMA and CD31. TNG-Ngs accelerated wound healing by promoting collagen deposition and angiogenic activity, as well as reducing inflammation. The findings indicated that TNG-Ngs is expected to be well vascularized in the wound area and to be more effective in topical therapy.

A thermoresponsive chitosan-based in situ gel formulation incorporated with 5-FU loaded nanoerythrosomes for fibrosarcoma local chemotherapy.

Local administration of drugs at tumor sites over an extended period of time shows potential as a promising approach for cancer treatment. In the present study, the temperature-induced phase transition of chitosan and poloxamer 407 is used to construct an injectable hydrogel encapsulating 5-FU-loaded nanoerythrosome (5-FU-NER-gel). The 5-FU-NERs were found to be spherical, measuring approximately 115 ± 20 nm in diameter and having a surface potential of -7.06 ± 0.4. The drug loading efficiency was approximately 40 %. In situ gel formation took place within 15 s when the gel was exposed to body temperature or subcutaneous injection. A sustained release profile was observed at pH 7.4 and 6.8, with a total 5-FU release of 76.57 ± 4.4 and 98.07 ± 6.31 in 24 h, respectively. MTT, Live/dead, and migration assays confirmed the cytocompatibility of the drug carrier and its effectiveness as a chemotherapeutic formulation. After in vivo antitumor assessment in a subcutaneous autograft model, it was demonstrated that tumor growth inhibition in 14 days was 90 %. Therefore, the obtained injectable chitosan-based hydrogel containing 5-FU-loaded nanoerythrosomes illustrated promising potential as a candidate for local and enhanced delivery of chemotherapeutics at the tumor site.

Effect of a single versus serial platelet-rich plasma injection on the healing of acute patellar tendon defect: an experimental study.

BACKGROUND: There is no consensus on the frequency and timing of platelet-rich plasma (PRP) injection in tendon healing. We aimed to evaluate the effectiveness of single versus multiple PRP injections in the healing of patellar tendon defects in the experimental model, through histological and biomechanical investigation. METHODS: Forty-four male skeletally mature Dutch rabbits were randomly divided into the five study groups ( A, B,C, D,E). After creating a longitudinal acute patellar tendon defect on both knees (One-third the width of the patella tendon), the right legs of the rabbits were used as the intervention group and the left legs as the control groups. Animals in groups A, B, and C were euthanized on days 7, 14, and 28, respectively, after the first PRP injection. Animals in group D received the second PRP injection on day 10 and was euthanized on day 14. Animals in group D received the second and third PRP injections on days 10 and 20, respectively, and were euthanized on day 28. The outcomes were evaluated histologically (modification of Movin's Grading) and biomechanically. RESULTS: The inflammatory condition was exaggerated in groups D and E. Load at failure was higher in the non-injected side of groups D and E, while there was no significant difference between the right and left legs of the three groups A, B and C. In other word, groups with a single PRP injection were more resistant to the increasing load compared to the groups with multiple PRP injections. CONCLUSIONS: PRP improves tendon healing if injected early after injury, while its injection after the initial phase of injury hampers tendon healing. In addition, a single PRP injection seems to be more effective than multiple PRP injection. Therefore, in cases where PRP injection is indicated for tendon repair, such as acute tendon injury, we recommend using a single PRP injection during tendon repair surgery.

The effects of simvastatin-loaded nanoliposomes on human multilineage liver fibrosis microtissue.

In this in vitro study, for the first time, we evaluate the effects of simvastatin-loaded liposome nanoparticles (SIM-LipoNPs) treatment on fibrosis-induced liver microtissues, as simvastatin (SIM) has shown potential benefits in the non-alcoholic fatty liver disease process. We developed multicellular liver microtissues composed of hepatic stellate cells, hepatoblastoma cells and human umbilical vein endothelial cells. The microtissues were supplemented with a combination of palmitic acid and oleic acid to develop fibrosis models. Subsequently, various groups of microtissues were exposed to SIM and SIM-LipoNPs at doses of 5 and 10 mg/mL. The effectiveness of the treatments was evaluated by analysing cell viability, production of reactive oxygen species (ROS) and nitric oxide (NO), the expression of Kruppel-like factor (KLF) 2, and pro-inflammatory cytokines (interleukin(IL)-1 α, IL-1 ß, IL-6 and tumour necrosis factor-α), and the expression of collagen I. Our results indicated that SIM-LipoNPs application showed promising results. SIM-LipoNPs effectively amplified the SIM-klf2-NO pathway at a lower dosage compatible with a high dosage of free SIM, which also led to reduced oxidative stress by decreasing ROS levels. SIM-LipoNPs administration also resulted in a significant reduction in pro-inflammatory cytokines and Collagen I mRNA levels, as a marker of fibrosis. In conclusion, our study highlights the considerable therapeutic potential of using SIM-LipoNPs to prevent liver fibrosis progress, underscoring the remarkable properties of SIM-LipoNPs in activating the KLF2-NO pathway and anti-oxidative and anti-inflammatory response.

Impact of sarcopenia on clinical outcomes in pediatric chronic liver disease post-liver transplantation: prevalence and implications.

Aim: The purpose of this retrospective single-center study was to determine the frequency of sarcopenia and its association with mortality and other morbidities in children with chronic liver disease who had undergone liver transplantation. Background: Sarcopenia, a muscle-wasting syndrome, is common in patients with advanced liver disease and is associated with increased morbidity and mortality. While sarcopenia in adults has been extensively studied, there is little information in this regard about children and adolescents with chronic liver diseases. Methods: The study included 108 children and adolescents who had undergone liver transplantation. Sarcopenia was measured using skeletal muscle index at the third lumbar vertebral level and assessed using abdominal computed tomography imaging. Results: The frequency of sarcopenia in the studied population was found to be 45.7%. Patients with sarcopenia were more likely to be male (P<0.0001), older (P<0.0001), and had lower height-for-age z-scores (P=0.012). Genetic/metabolic diseases were the most common underlying cause of sarcopenia in children. Except for a higher rate of transplant rejection in the sarcopenia group (P=0.035), there was no significant difference in mortality rates (P=0.688) or post-LT complications between the two groups. One year after LT, computed tomography-derived body composition parameters revealed no significant differences between children who survived and those who did not. Conclusion: Our findings indicated a high frequency of sarcopenia in children with chronic liver disease, implying that more research is needed to better understand its impact on clinical outcomes in this population.

Droplet-based microfluidics: an efficient high-throughput portable system for cell encapsulation.

One of the goals of tissue engineering and regenerative medicine is restoring primary living tissue function by manufacturing a 3D microenvironment. One of the main challenges is protecting implanted non-autologous cells or tissues from the host immune system. Cell encapsulation has emerged as a promising technique for this purpose. It involves entrapping cells in biocompatible and semi-permeable microcarriers made from natural or synthetic polymers that regulate the release of cellular secretions. In recent years, droplet-based microfluidic systems have emerged as powerful tools for cell encapsulation in tissue engineering and regenerative medicine. These systems offer precise control over droplet size, composition, and functionality, allowing for creating of microenvironments that closely mimic native tissue. Droplet-based microfluidic systems have extensive applications in biotechnology, medical diagnosis, and drug discovery. This review summarises the recent developments in droplet-based microfluidic systems and cell encapsulation techniques, as well as their applications, advantages, and challenges in biology and medicine. The integration of these technologies has the potential to revolutionise tissue engineering and regenerative medicine by providing a precise and controlled microenvironment for cell growth and differentiation. By overcoming the immune system's challenges and enabling the release of cellular secretions, these technologies hold great promise for the future of regenerative medicine.

Hypoxia-preconditioned WJ-MSC spheroid-derived exosomes delivering miR-210 for renal cell restoration in hypoxia-reoxygenation injury.

BACKGROUND: Recent advancements in mesenchymal stem cell (MSC) technology have paved the way for innovative treatment options for various diseases. These stem cells play a crucial role in tissue regeneration and repair, releasing local anti-inflammatory and healing signals. However, challenges such as homing issues and tumorigenicity have led to exploring MSC-exosomes as a promising alternative. MSC-exosomes have shown therapeutic potential in conditions like renal ischemia-reperfusion injury, but low production yields hinder their clinical use. METHODS: To address this limitation, we examined hypoxic preconditioning of Wharton jelly-derived MSCs (WJ-MSCs) 3D-cultured in spheroids on isolated exosome yields and miR-21 expression. We then evaluated their capacity to load miR-210 into HEK-293 cells and mitigate ROS production, consequently enhancing their survival and migration under hypoxia-reoxygenation conditions. RESULTS: MiR-210 overexpression was significantly induced by optimized culture and preconditioning conditions, which also improved the production yield of exosomes from grown MSCs. The exosomes enriched with miR-210 demonstrated a protective effect by improving survival, reducing apoptosis and ROS accumulation in damaged renal cells, and ultimately promoting cell migration. CONCLUSION: The present study underscores the possibility of employing advanced techniques to maximize the therapeutic attributes of exosomes produced from WJ-MSC spheroid for improved recovery outcomes in ischemia-reperfusion injuries.

Unlocking a New Path: An Autophagometer that Measures Flux Using a Non-Fluorescent Immunohistochemistry Method.

Macroautophagy/autophagy, a crucial cellular process, is typically measured using fluorescence-based techniques, which can be costly, complex, and impractical for clinical settings. In this paper, we introduce a novel, cost-effective, non-fluorescent immunohistochemistry (IHC) method for evaluating autophagy flux. This technique, based on antigen-antibody reactions and chromogenic detection, provides clear, quantifiable results under standard light microscopy, eliminating the need for expensive equipment and specialized reagents. Our method simplifies technical requirements, making it accessible to routine clinical laboratories and research settings with limited resources. By comparing our approach with traditional fluorescence methods, we demonstrate its superior effectiveness, cost-efficiency, and applicability to patient samples. This innovative technique has the potential to significantly advance autophagy research and improve clinical diagnostics, offering a practical and robust tool for studying autophagy mechanisms in diseases such as cancer and neurodegenerative disorders. Our non-fluorescent IHC method represents a significant step forward in evaluating autophagy flux, making it more accessible and reliable, with the promise of enhancing our understanding and treatment of autophagy-related diseases.

Enhancing volumetric muscle loss (VML) recovery in a rat model using super durable hydrogels derived from bacteria.

Bacteria can be programmed to deliver natural materials with defined biological and mechanical properties for controlling cell growth and differentiation. Here, we present an elastic, resilient and bioactive polysaccharide derived from the extracellular matrix of Pantoea sp. BCCS 001. Specifically, it was methacrylated to generate a new photo crosslinkable hydrogel that we coined Pantoan Methacrylate or put simply PAMA. We have used it for the first time as a tissue engineering hydrogel to treat VML injuries in rats. The crosslinked PAMA hydrogel was super elastic with a recovery nearing 100 %, while mimicking the mechanical stiffness of native muscle. After inclusion of thiolated gelatin via a Michaelis reaction with acrylate groups on PAMA we could also guide muscle progenitor cells into fused and aligned tubes - something reminiscent of mature muscle cells. These results were complemented by sarcomeric alpha-actinin immunostaining studies. Importantly, the implanted hydrogels exhibited almost 2-fold more muscle formation and 50 % less fibrous tissue formation compared to untreated rat groups. In vivo inflammation and toxicity assays likewise gave rise to positive results confirming the biocompatibility of this new biomaterial system. Overall, our results demonstrate that programmable polysaccharides derived from bacteria can be used to further advance the field of tissue engineering. In greater detail, they could in the foreseeable future be used in practical therapies against VML.

CAR-T cell-derived exosomes: a new perspective for cancer therapy.

Chimeric antigen receptor (CAR)-T cell adoptive immunotherapy is a promising cancer treatment that uses genetically engineered T cells to attack tumors. However, this therapy can have some adverse effects. CAR-T cell-derived exosomes are a potential alternative to CAR-T cells that may overcome some limitations. Exosomes are small vesicles released by cells and can carry a variety of molecules, including proteins, RNA, and DNA. They play an important role in intercellular communication and can be used to deliver therapeutic agents to cancer cells. The application of CAR-T cell-derived exosomes could make CAR-T cell therapy more clinically controllable and effective. Exosomes are cell-free, which means that they are less likely to cause adverse reactions than CAR-T cells. The combination of CAR-T cells and exosomes may be a more effective way to treat cancer than either therapy alone. Exosomes can deliver therapeutic agents to cancer cells where CAR-T cells cannot reach. The appropriate application of both cellular and exosomal platforms could make CAR-T cell therapy a more practicable treatment for cancer. This combination therapy could offer a safe and effective way to treat a variety of cancers.

Comparison of Mir122 expression in children with biliary atresia and healthy group.

Biliary atresia (BA) is the primary cause of neonatal jaundice with various pathological mechanisms. Many BA patients may experience progressive liver dysfunction and eventually need a liver transplant. Therefore, identifying potential non-invasive biomarkers for BA is crucial. miR-122, the most abundant microRNA in the liver, plays significant roles in different liver diseases. This study aimed to assess miR-122 levels in BA patients. Eighteen patients with biliary atresia were selected at random from the Shiraz Pediatric Liver Cirrhosis Cohort Study (SPLCCS), along with 18 healthy controls. Blood samples were collected, and biochemical parameters (such as liver function tests) were measured. Quantitative reverse-transcription PCR (RT-PCR) was conducted on serum samples from both the case and control groups to analyze miR-122 levels. The study results indicated that serum miR-122 expression in BA patients was elevated compared to the control group, although it did not reach statistical significance. Additionally, no correlation was found between miR-122 expression and serum levels of liver enzymes or other laboratory findings in BA cases. miR-122 could be a potential target for diagnosing BA; however, further research with a larger population is necessary to determine if miR-122 could serve as a useful biomarker for diagnosing BA.

Molecular Prospective on Malignant Transformation of Mesenchymal Stem Cells: An Issue in Cell Therapy.

Mesenchymal stem cell (MSCs) therapy, as a rapidly developing area of medicine, holds great promise for the treatment of a variety of medical conditions. MSCs are multipotent stem cells that can be isolated from various tissues and could self-renew and differentiate. They secrete cytokines and trophic factors that create a regenerative microenvironment and have immunomodulatory properties. Although clinical trials have been conducted with MSCs in various diseases, concerns regarding the possibility of malignant transformation of these cells have been raised. The studies showed a higher rate of hematological malignancy and carcinogenesis in experimental models after MSC transplantation. The mechanisms underlying malignant transformation of MSCs are complex and not fully understood, but they are believed to involve the presence of special signaling molecules and alterations in cell behavior regulation pathways. Possible pathways that lead to MSCs' oncogenic transformation occur through two mechanisms: spontaneous and stimulated malignant transformation, including cell fusion, fusion proteins, and the tumor microenvironment. MSC-based therapies have the potential to revolutionize medicine, and addressing the issue of malignancy is crucial to ensure their safety and efficacy. Therefore, the purpose of the present review is to summarize the potential mechanisms of the malignant transformation of MSCs. [Figure: see text].

GDF11: An emerging therapeutic target for liver diseases and fibrosis.

Growth differentiation factor 11 (GDF11), also known as bone morphogenetic protein 11 (BMP11), has been identified as a key player in various biological processes, including embryonic development, aging, metabolic disorders and cancers. GDF11 has also emerged as a critical component in liver development, injury and fibrosis. However, the effects of GDF11 on liver physiology and pathology have been a subject of debate among researchers due to conflicting reported outcomes. While some studies suggest that GDF11 has anti-aging properties, others have documented its senescence-inducing effects. Similarly, while GDF11 has been implicated in exacerbating liver injury, it has also been shown to have the potential to reduce liver fibrosis. In this narrative review, we present a comprehensive report of recent evidence elucidating the diverse roles of GDF11 in liver development, hepatic injury, regeneration and associated diseases such as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), liver fibrosis and hepatocellular carcinoma. We also explore the therapeutic potential of GDF11 in managing various liver pathologies.

Harnessing the Potential of Self-Assembled Peptide Hydrogels for Neural Regeneration and Tissue Engineering.

Spinal cord injury, traumatic brain injury, and neurosurgery procedures usually lead to neural tissue damage. Self-assembled peptide (SAP) hydrogels, a type of innovative hierarchical nanofiber-forming peptide sequences serving as hydrogelators, have emerged as a promising solution for repairing tissue defects and promoting neural tissue regeneration. SAPs possess numerous features, such as adaptable morphologies, biocompatibility, injectability, tunable mechanical stability, and mimicking of the native extracellular matrix. This review explores the capacity of neural cell regeneration and examines the critical aspects of SAPs in neuroregeneration, including their biochemical composition, topology, mechanical behavior, conductivity, and degradability. Additionally, it delves into the latest strategies involving SAPs for central or peripheral neural tissue engineering. Finally, the prospects of SAP hydrogel design and development in the realm of neuroregeneration are discussed.

The effects of combined and independent low-level laser and mesenchymal stem cell therapy on induced knee osteoarthritis: An animal study.

BACKGROUND: Mesenchymal stem cell (MSC) injection has emerged as a novel treatment for knee osteoarthritis (OA). In addition, low-level laser therapy (LLLT) has been reported to delay the progression of OA. Thus, the current study on animal models of OA investigated the effectiveness of these methods when administered independently and combined. METHODS: Twenty-five guinea pig models of OA were randomly sorted into five study groups. The test groups received intra-articular MSC, LLLT, and a combination of these therapeutics for 8 weeks. Radiological and histopathologic evaluations were carried out for the test groups and the control after the completion of treatments. RESULTS: The MSC-treated groups showed better outcomes in terms of all radiological and histological indexes compared with the control, apart from subchondral bone (P < 0.05). Similarly, but to a different extent, the LLLT-treated group showed better results than the controls (P < 0.05). The combination of MSC therapy and LLLT improved the cartilage, surface, matrix, space width, osteophytes, and radiologic OA scores more effectively than each of these methods alone (P < 0.05). CONCLUSIONS: According to our results, the combination of intra-articular MSC and LLLT can effectively improve OA in animal models. Further preclinical and clinical studies are recommended to assess the effectiveness of these therapeutics alone and in combination.

Gens PSD-95 and GSK-3ß expression improved by hair follicular stem cells-conditioned medium enhances synaptic transmission and cognitive abilities in the rat model of vascular dementia.

INTRODUCTION: Vascular dementia (VaD) is a common type of dementia. The aim of this study was to investigate the cellular and molecular mechanism of conditioned medium (CM) in VaD. MATERIAL AND METHODS: The rats were divided into four groups of control (n = 9), sham-operation (n = 10), VaD with vehicle (n = 9), and VaD with CM (n = 12) that received CM on days 4, 14, and 24 after 2VO. Before sacrificing the rats, cognitive performance was assessed through the open-field (OP), passive-avoidance, and Morris-water maze. The field-potential recording was used to investigate basal synaptic transmission (BST) and long-term potentiation (LTP). Subsequently, the hippocampus was dissected, and real-time PCR was used to quantify the expression levels of ß1-catenin, insulin-like growth factor-1 (IGF-1), transforming growth factor-beta (TGF-ß), glycogen synthase kinase-3ß (GSK-3ß), postsynaptic density protein 95 (PSD-95), and NR2B genes. RESULTS: The results indicated impaired performance in behavioral tests in 2VO rats, coupled with reductions in BST and LTP induction. The expression levels of ß1-catenin, IGF-1, PSD-95, and TGF-ß genes decreased, whereas NR2B and GSK-3ß expression increased. Treatment with CM restores the expression of PSD-95 and GSK-3ß as well as fear-memory, spatial learning, and grooming number without a positive effect on memory retrieval, time spent on the periphery and center of OP. The BST recovered upon administration of CM but, the LTP induction was still impaired. CONCLUSION: The recovery of BST in VaD rats appears to be the most important outcome of this study which is caused by the improvement of gene expression and leads to the restoration of fear memory.

Circulating Nucleic Acids in Colorectal Cancer: Diagnostic and Prognostic Value.

Colorectal cancer (CRC) is the third most prevalent cancer in the world and the fourth leading cause of cancer-related mortality. DNA (cfDNA/ctDNA) and RNA (cfRNA/ctRNA) in the blood are promising noninvasive biomarkers for molecular profiling, screening, diagnosis, treatment management, and prognosis of CRC. Technological advancements that enable precise detection of both genetic and epigenetic abnormalities, even in minute quantities in circulation, can overcome some of these challenges. This review focuses on testing for circulating nucleic acids in the circulation as a noninvasive method for CRC detection, monitoring, detection of minimal residual disease, and patient management. In addition, the benefits and drawbacks of various diagnostic techniques and associated bioinformatics tools have been detailed.

The role of non-protein-coding RNAs in ischemic acute kidney injury.

Acute kidney injury (AKI) is a condition characterized by a rapid decline in kidney function within a span of 48 hours. It is influenced by various factors including inflammation, oxidative stress, excessive calcium levels within cells, activation of the renin-angiotensin system, and dysfunction in microcirculation. Ischemia-reperfusion injury (IRI) is recognized as a major cause of AKI; however, the precise mechanisms behind this process are not yet fully understood and effective treatments are still needed. To enhance the accuracy of diagnosing AKI during its early stages, the utilization of innovative markers is crucial. Numerous studies suggest that certain noncoding RNAs (ncRNAs), such as long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), play a central role in regulating gene expression and protein synthesis. These ncRNAs are closely associated with the development and recovery of AKI and have been detected in both kidney tissue and bodily fluids. Furthermore, specific ncRNAs may serve as diagnostic markers and potential targets for therapeutic interventions in AKI. This review aims to summarize the functional roles and changes observed in noncoding RNAs during ischemic AKI, as well as explore their therapeutic potential.

Expression of miR-let7b and miR-19b in progressive familial intrahepatic cholestasis (PFIC) children.

BACKGROUND: MicroRNAs (miRNAs) are a group of small non-coding RNAs that bind to the target mRNA and regulate gene expression. Recently circulating microRNAs were investigated as markers of diseases and therapeutic targets. Although various studies analyze the miRNA expression in liver disease, these studies on PFIC are few. Progressive familial intrahepatic cholestasis (PFIC) is a rare liver disease with autosomal recessive inheritance. Most children with PFIC progress to cirrhosis and liver failure and consequently need to have a liver transplant. The aim of this study is the investigation of the miR-19b and miR-let7b expression levels in Iranian PFIC children. METHODS: 25 PFIC patients, 25 healthy children and 25 Biliary Atresia patients were considered as case and two control groups respectively. Blood samples were obtained and Liver function tests (LFTs) were measured. After RNA extraction and cDNA synthesis, quantitative PCR was performed using specific primers for miR-19b and miR-let7b. The U6 gene is used as an internal control. RESULTS: qPCR on PFIC patients' samples demonstrated that the miR-19b and the miR-let7b expression were significantly decreased in patients compared to the control groups, with a p-value<0.0001 and p-value=0.0006 receptively. CONCLUSION: In conclusion, circulating micro-RNA like miR-19b and miR-let7b have a potential opportunity to be a non-invasive diagnostic marker or therapeutic target for PFIC in the future.