Stem Cell Technology Research Articles

Gene Therapy for Hemoglobinopathies.

β-Thalassemia and sickle cell disease are autosomal recessive disorders of red blood cells due to mutations in the adult β-globin gene, with a worldwide diffusion. The severe forms of hemoglobinopathies are fatal if untreated, and allogeneic bone marrow transplantation can be offered to a limited proportion of patients. The unmet clinical need and the disease incidence have promoted the development of new genetic therapies based on the engineering of autologous hematopoietic stem cells. Here, the steps of ex vivo gene therapy development are reviewed along with results from clinical trials and recent new approaches employing cutting edge gene editing tools.

A novel protocol to derive cervical motor neurons from induced pluripotent stem cells for amyotrophic lateral sclerosis.

Sporadic amyotrophic lateral sclerosis (sALS) is the majority of ALS, and the lack of appropriate disease models has hindered its research. Induced pluripotent stem cell (iPSC) technology now permits derivation of iPSCs from somatic cells of sALS patients to investigate disease phenotypes and mechanisms. Most existing differentiation protocols are time-consuming or low efficient in generating motor neurons (MNs). Here we report a rapid and simple protocol to differentiate MNs in monolayer culture using small molecules, which led to nearly pure neural stem cells in 6days, robust OLIG2+ pMNs (73%-91%) in 12days, enriched CHAT+ cervical spinal MNs (sMNs) (88%-97%) in 18days, and functionally mature sMNs in 28days. This simple and reproducible protocol permitted the identification of hyperexcitability phenotypes in our sALS iPSC-derived sMNs, and its application in neurodegenerative diseases should facilitate invitro disease modeling, drug screening, and the development of cell therapy.

Protective Effect of Docetaxel Against Autophagy-Related Genes in Vitrification of Mouse Metaphase II Oocytes.

Autophagy is a conservative mechanism for cell survival as the main response of cells to stress conditions. The present study aimed to assess the effect of docetaxel on the survival, fertilization, and expression of autophagy-related genes in vitrified oocytes. The study was conducted in 2018 at the Stem Cells Technology Research Center, Shiraz University of Medical Sciences (Shiraz, Iran). Denuded oocytes were randomly selected and assigned to five groups, namely control (n=133), docetaxel (n=136), docetaxel+cryoprotectants (n=146), docetaxel+vitrification (n=138), and vitrification (n=145). The effect of vitrification on the expression of autophagy-related gene 5 (ATG5) and Beclin-1 was determined using a real-time polymerase chain reaction. Data were analyzed using SPSS software (version 26.0) and GraphPad Prism 9. Survival and fertilization rates in each experimental group were significantly reduced compared to the control group (P=0.001). After in vitro fertilization of oocytes, the 2-cell formation rate was significantly reduced in the docetaxel+vitrification and vitrification groups compared to the control and docetaxel groups (P=0.001 and P=0.001, respectively). Pre-incubation of oocytes with docetaxel reduced gene expression levels of Beclin-1 and ATG5 in the docetaxel+cryoprotectants and docetaxel+vitrification groups (P=0.001 and P=0.019, respectively). The expression level of these genes was also reduced in the docetaxel group compared to the control group (P=0.001). Incubation of mouse metaphase II oocytes with docetaxel prior to vitrification reduced the expression of autophagy-related genes and increased survival and fertilization rates compared to untreated oocytes.

Harnessing the Therapeutic Potential of Stem Cells in the Management of Chronic Obstructive Pulmonary Disease: A Comprehensive Review.

Chronic obstructive pulmonary disease (COPD) is a prevalent and debilitating respiratory condition with limited treatment options. Stem cell therapy has emerged as a promising approach for COPD management due to its regenerative and immunomodulatory properties. This review article aims to comprehensively explore the therapeutic potential of stem cells in COPD management. The introduction provides background on COPD, highlighting its impact on health and the need for novel therapies. The different types of stem cells relevant to COPD, including embryonic stem cells, adult stem cells, and induced pluripotent stem cells, are described along with their properties and characteristics. The pathogenesis of COPD is discussed, emphasizing the key mechanisms involved in disease development and progression. Subsequently, the role of stem cells in tissue repair, regeneration, and immunomodulation is examined, highlighting their ability to address specific pathological processes in COPD. Mechanisms of action, such as paracrine signaling, immunomodulation, anti-inflammatory effects, and tissue regeneration, are explored. The interaction between stem cells and the host environment, which promotes lung repair, is also discussed. Challenges in stem cell therapy for COPD, including optimal cell sources, delivery methods, safety, and efficacy, are identified. Regulatory considerations and the importance of standardization are emphasized. Potential strategies for optimizing the therapeutic potential of stem cells in COPD management, such as combination therapies and preconditioning techniques, are outlined. Emerging trends and future directions are highlighted, including advanced cell engineering and patient-specific induced pluripotent stem cells. In conclusion, stem cell therapy holds significant promise for COPD management, addressing the limitations of current treatments. Continued research and development are necessary to overcome challenges, optimize therapies, and realize stem cells' full potential in improving the lives of patients with COPD.

352. GENERATION OF PATIENT-DERIVED ESOPHAGEAL ADENOCARCINOMA ORGANOIDS FROM CIRCULATING TUMOR CELLS

Abstract Background Esophageal adenocarcinoma (EAC) is diagnosed in nearly 40% of patients when their cancer has already metastasized. Circulating tumor cells (CTCs) play a critical role in the metastatic cascade and need to be investigated in the context of EAC, but these must be expanded due to their scarcity in blood. Organoid models have been shown to recapitulate tumor heterogeneity and in vivo drug sensitivity. Thus, we aim to generate and characterize CTC-derived organoids from EAC patients. Methods CTCs were isolated from 32 blood samples obtained from 13 EAC patients using two methods: (1) Ficoll-based density gradient centrifugation followed by CD45+ cell depletion using magnetic-activated cell sorting (MACS) and/or (2) immunodensity separation using the RosetteSep CTC Enrichment Cocktail (Stemcell Technologies). Isolated CTCs were embedded and grown in Matrigel domes. Cultures were dissociated into single cells which were magnetically labelled and captured on a microfluidic chip. The captured cells were stained with DAPI, anti-CD45, anti-CK11, anti-CK13, and anti-CK18 antibodies. These cells were then visualized and quantified using fluorescence microscopy. Results Organoids were generated from twenty-one out of thirty-two samples, after two to six weeks in culture, with an average of 20.76 ± 6.435 organoids per sample. These EAC CTC derived organoids underwent a growth arrest once they reached an arbitrary size but were able to regenerate upon dissociation and re-seeding. However, no increase in the size or number of organoids was observed post-passaging. Of the nine CTC-derived organoid samples characterized using microfluidic capture and immunostaining, all nine had the presence of CD45 negative, CK positive, and DAPI positive cells. Conclusion In this study, we validated commonly used CTC isolation methods and were able to demonstrate that CTCs isolated can be cultured to generate organoids. Additional investigation is required to overcome the growth arrest which occurs during culture.

Coordinated Biophysical Stimulation of MSCs via Electromagnetized Au‐Nanofiber Matrix Regulates Cytoskeletal‐to‐Nuclear Mechanoresponses and Lineage Specification

AbstractBiophysical stimulation regulates stem cell functions, including proliferation and differentiation. Matrix nanotopography and external forces, such as electromagnetic fields (EMF), can enhance this stimulation. Here, it is demonstrated that biophysical multiple cues coordinated from electromagnetized Au‐nanoparticles‐decorated polymer nanofiber under EMF significantly regulate the adhesion, alignment, proliferation, and lineage commitment of hMSCs. Without EMF, matrix cues of electrical conductivity and nanodotted fibrous topography accelerate the anchorage and spreading of hMSCs. Of note, EMF synergizes with the matrix cues to enhance cellular behaviors, resulting in elongated and aligned cells along the field direction. Microtubules are highly polymerized, acetylated, and aligned, playing an active role in these events. Actin filaments also develop in parallel with the microtubules, facilitating actin‐microtubule crosstalks. These phenomena lead to changes in the nuclear mechanics of hMSCs, including elongated nuclear shape and decondensed chromatins with histone acetylation. The EMF+matrix‐stimulated hMSCs express genes related to microtubule organization and euchromatin, as revealed by RNA sequencing, and show chromatin accessibility with enrichment of genes related to mechanotransduction and lineage specification, as analyzed by ATAC sequencing. The EMF+matrix biophysical stimulation further increases the capacity for lineage specification (predominantly towards osteogenic, myogenic, and tenogenic), offering a promising bioengineering platform for stem cell engineering and therapies.

Harnessing the dental cells derived from human induced pluripotent stem cells for hard tissue engineering

IntroductionMost mineralized tissues in our body are present in bones and teeth. Human induced pluripotent stem cells (hiPSCs) are promising candidates for cell therapy to help regenerate bone defects and teeth loss. The extracellular matrix (ECM) is a non-cellular structure secreted by cells. Studies on the dynamic microenvironment of ECM are necessary for stem cell-based therapies. ObjectivesWe aim to optimize an effective protocol for hiPSC differentiation into dental cells without utilizing animal-derived factors or cell feeders that can be applied to humans and to mineralize differentiated dental cells into hard tissues. MethodsFor the differentiation of both dental epithelial cells (DECs) and dental mesenchymal cells (DMCs) from hiPSCs, an embryoid body (EB) was formed from hiPSCs. hiPSC were differentiated into neural crest cells with an induction medium utilized in our previous study, and hiPSC-derived DECs were differentiated with a BMP-modulated customized medium. hiPSC-dental cells were then characterized, analyzed, and validated with transcriptomic analysis, western blotting, and RT-qPCR. To form mineralized tissues, hiPSC-derived DECs were recombined with hiPSC-derived DMCs encapsulated in various biomaterials, including gelatin methacryloyl (GelMA), collagen, and agar matrix. ResultsThese hiPSC-derived dental cells are highly osteogenic and chondro-osteogenic in photocrosslinkable GelMA hydrogel and collagen type I microenvironments. Furthermore, hiPSC-derived dental cells in agar gel matrix induced the formation of a bioengineered tooth. ConclusionOur study provides an approach for applying hiPSCs for hard tissue regeneration, including tooth and bone. This study has immense potential to provide a novel technology for bioengineering organs for various regenerative therapies.

The patent landscape in the field of stem cell therapy: closing the gap between research and clinic.

Stem cell technology is a powerful tool ready to respond to the needs of modern medicine that is experiencing rapid technological development. Given its potential in therapeutic applications, intellectual property rights (IPR) as a protection resource of knowledge are a relevant topic. Patent eligibility of stem cells has been controversial as restrictions to access the fundamental technologies open a gap between research and clinic. Therefore, we depicted the current patent landscape in the field to discuss if this approach moves forward in closing this breach by examining patent activity over the last decade from a transdisciplinary perspective. Stem cell therapeutic applications is an area of continuous growth where patent filing through the PCT is the preferred strategy. Patenting activity is concentrated in the USA, European Union, and Australia; this accumulation in a few key players leads to governance, regulation, and inequality concerns. To boost wealthiness and welfare in society - stem cell therapies' ultimate goal - while at post-pandemic recovery, critical elements in the field of IPR rise to overcome current limitations: to promote bridge builders able to connect the research and business worlds, regulatory updates, novel financing models, new vehicles (startups, spinouts, and spin-offs), and alternative figures of intellectual property.

Capitalization of Graphene/Chitosan Nanocomposites as Intriguing Vehicles for Targeted Anti‐Cancer Drug Delivery

AbstractThe effective combination of various polysaccharides with graphene derivatives toward the formation of nanocomposites has gained enormous interest for a number of emerging biological and biomedical applications. The intriguing properties of the individual materials are further improved upon the realization of (nano)composites, thus providing new insights and property enhancement in terms of durability, flexibility, biocompatibility, low‐toxicity, and antibacterial/antimicrobial behavior. Therefore, novel (nano)composite agents are prepared and investigated to serve as ideal carriers or scaffold materials in regenerative medicine, biosensing, disease diagnosis and treatment, drug delivery, as well as stem cell and tissue engineering applications. This topical review summarizes the most recent studies published during the last quinquennium (2018–2022), on the development of anticancer drug delivery systems (DDSs) based on graphene/chitosan (CS) nanocomposites. The followed synthetic routes and the integrated properties of the composite materials are analyzed, discussing the impact of their utilization in the field of drug delivery for the treatment of various cancer types. The prospects and future research trends in the field are also discussed.

An Improved Protocol for Targeted Differentiation of Primed Human Induced Pluripotent Stem Cells into HLA-G-Expressing Trophoblasts to Enable the Modeling of Placenta-Related Disorders.

Abnormalities at any stage of trophoblast development may result in pregnancy-related complications. Many of these adverse outcomes are discovered later in pregnancy, but the underlying pathomechanisms are constituted during the first trimester. Acquiring developmentally relevant material to elucidate the disease mechanisms is difficult. Human pluripotent stem cell (hPSC) technology can provide a renewable source of relevant cells. BMP4, A83-01, and PD173074 (BAP) treatment drives trophoblast commitment of hPSCs toward syncytiotrophoblast (STB), but lacks extravillous trophoblast (EVT) cells. EVTs mediate key functions during placentation, remodeling of uterine spiral arteries, and maintenance of immunological tolerance. We optimized the protocol for a more efficient generation of HLA-Gpos EVT-like trophoblasts from primed hiPSCs. Increasing the concentrations of A83-01 and PD173074, while decreasing bulk cell density resulted in an increase in HLA-G of up to 71%. Gene expression profiling supports the advancements of our treatment regarding the generation of trophoblast cells. The reported differentiation protocol will allow for an on-demand access to human trophoblast cells enriched for HLA-Gpos EVT-like cells, allowing for the elucidation of placenta-related disorders and investigating the immunological tolerance toward the fetus, overcoming the difficulties in obtaining primary EVTs without the need for a complex differentiation pathway via naïve pluripotent or trophoblast stem cells.

Cost-Effectiveness Analysis of Regenerative Endodontics versus MTA Apexification.

With the introduction of stem cell engineering in dentistry, regenerative endodontics has emerged as a potential alternative to mineral trioxide aggregate (MTA) apexification in the management of necrotic immature permanent teeth. However, the utility of this modality in terms of cost-effectiveness has not yet been established. Therefore, we performed cost-effectiveness analysis to determine the dominant treatment modality that would influence decision making from the private payer perspective. A Markov model was constructed with a necrotic immature permanent tooth in a 7-y-old patient, followed over the lifetime using TreeAge Pro Healthcare 2022. Transition probabilities were estimated based on the existing literature. Costs were estimated based on United States health care, and cost-effectiveness was determined using Monte Carlo microsimulations. The model was validated internally by sensitivity analyses, and face validation was performed by an experienced endodontist and health economist. In the base-case scenario, regenerative endodontics did not turn out to be a dominant treatment option as it was associated with an additional cost of USD$1,012 and fewer retained tooth-years (15.48 y). Likewise, in the probabilistic sensitivity analysis, regenerative endodontics was again dominated by apexification against different willingness-to-pay values. Based on current evidence, regenerative endodontic treatment was not cost-effective compared with apexification in the management of necrotic immature permanent teeth over an individual's lifetime. The study provides valuable insight regarding the cost valuation and cost-efficacy of regenerative endodontic treatment versus apexification in the management of necrotic immature permanent teeth, as this would aid in effective clinical decision making, allowing for the functional allocation of resources.

Oxytocin Receptor Expression in Hair Follicle Stem Cells: A Promising Model for Biological and Therapeutic Discovery in Neuropsychiatric Disorders.

The intricate nature of the human brain and the limitations of existing model systems to study molecular and cellular causes of neuropsychiatric disorders represent a major challenge for basic research. The promising progress in patient-derived stem cell technology and in our knowledge on the role of the brain oxytocin (OXT) system in health and disease offer new possibilities in that direction. In this study, the rat hair follicle stem cells (HFSCs) were isolated and expanded in vitro. The expression of oxytocin receptors (OXTR) was evaluated in these cells. The cellular viability was assessed 12 h post stimulation with OXT. The activation of OXTR-coupled intracellular signaling cascades, following OXT treatment was determined. Also, the influence of OXT on neurite outgrowth and cytoskeletal rearrangement were defined. The assessment of OXTR protein expression revealed this receptor is expressed abundantly in HFSCs. As evidenced by the cell viability assay, no adverse or cytotoxic effects were detected following 12 h treatment with different concentrations of OXT. Moreover, OXTR stimulation by OXT resulted in ERK1/2, CREB, and eEF2 activation, neurite length alterations, and cytoskeletal rearrangements that reveal the functionality of this receptor in HFSCs. Here, we introduced the rat HFSCs as an easy-to-obtain stem cell model that express functional OXTR. This cell-based model can contribute to our understanding of the progression and treatment of neuropsychiatric disorders with oxytocinergic system deficiency.

Abstract P1108: Development Of A Vascularized Cardiac Patch Using 3D Bioprinting To Regenerate Injured Myocardium

Introduction: Regeneration of the myocardium after ischemic injuries has remained a challenge due to the low proliferative capacity of cardiomyocytes (CMs). With the advance of tissue engineering, various cardiac patch devices have been developed and shown to improve cardiac tissue structure/function after myocardial infarction (MI). However, the therapeutic outcomes of patch devices have been limited by the lack of biological and structural complexity. Leveraging 3D bioprinting and stem cell technologies, this study presents the development of a next generation cardiac patch, integrated with heterogenous multi-cellular architecture, perfusable vasculature, and pro-proliferative molecules. Methods: A hybrid functional bioink, consisting of gelatin methacrylate (GelMA), gelatin, and fibrin, was optimized to fabricate the patch constructs. Two small molecule-based CM expansion techniques were employed, utilizing follistatin-like protein 1 (FSTL1) and CHIR99021 (CHIR), to further enhance the regenerative capacity of the patch. Complex vascular geometries were created by bioprinting sacrificial pluronic bioink in between two cellular composite bioink layers, containing human induced pluripotent stem cell-derived CMs (hiPSC-CMs) and endothelial cells (ECs). The sacrificial ink was subsequently removed to create vascular channels, which were then endothelialized with ECs. Results: Bioprinted patches were successfully cultured under static and dynamic (physiologic flow) culture in vitro . The hiPSC-CMs encapsulated in gelMA-gelatin-fibrin bioink showed adequate long-term viability and function within the 3D environment. The printed vascular channels formed rather uniform endothelium. Both the FSTL1 and CHIR treatments resulted in significant in-situ expansion of hiPSC-CMs within bioprinted cardiac constructs. Further, testing the engineered patch in a rat MI model demonstrated the significant cardioprotective effect of patch. Conclusion: Together, this study introduces a new generation of bioprinted myocardial tissue analogues as a robust research-enabling platform for in vitro testing, and as a novel patch device with markedly enhanced regenerative capacity to treat diseased/damaged adult mammalian heart.

Abstract P1041: Multiplexed Cardiotoxicity And Efficacy Screening Using Kinetic Image Cytometry Of Human Induced Pluripotent Stem Cell-derived Cardiomyocytes

Traditionally, cardiotoxicity testing used low-throughput animal models which may not fully recapitulate human physiology. Stem cell technology enables screening in a more physiologically-relevant model system in less time and with less cost, but most current high-throughput screening modalities rely on whole-well or whole-field averaged data, which obfuscate the responses of individual hiPSC-cardiomyocytes (CMs). By measuring individual hiPSC-CMs, heterogenous responses that would otherwise be “averaged out” can be quantified, thus improving sensitivity. We previously published that the single-cell Kinetic Image Cytometry (KIC) methods developed at Vala Sciences predicted arrhythmogenic liability with an accuracy of 90% using intracellular Ca 2+ kinetics as a readout. In this study, we expand upon this methodology by loading metabolically matured hiPSC-CMs with Cal-520 (a green Ca 2+ dye) and BeRST-1 (a far red membrane voltage dye), acquiring interleaved movies of Ca 2+ and membrane potential at 60 Hz (30 Hz per channel). We then created image analysis algorithms to measure Ca 2+ transient (CT) and action potential (AP) kinetics, and to derive contraction measurements from those movies. To validate our approach, we exposed cells to isoproterenol, nifedipine, dofetilide, and butadiene 2-monoxime (BDM) at various concentrations. Isoproterenol increased beat rate, decreased both AP and CT durations, increased CT magnitude, and elicited a lusitropic effect. Nifedipine increased beat rate, decreased AP and CT durations, and reduced CT magnitude and contraction distance. Dofetilide reduced beat rate, prolonged APs and CTs, and increased contraction distance. BDM had multiple inhibitor effects on APs and CTs, and strongly reduced contraction. Thus, this multiplexed assay can quantify multiple effects of drugs on APs, CTs, and contraction, providing an unprecedented suite of information relevant to cardiosafety and efficacy.

Umbilical cord mesenchymal stem cells for regenerative treatment of intervertebral disc degeneration.

Intervertebral disc degeneration is thought to be a major contributor to low back pain, the etiology of which is complex and not yet fully understood. To compensate for the lack of drug and surgical treatment, mesenchymal stem cells have been proposed for regenerative treatment of intervertebral discs in recent years, and encouraging results have been achieved in related trials. Mesenchymal stem cells can be derived from different parts of the body, among which mesenchymal stem cells isolated from the fetal umbilical cord have excellent performance in terms of difficulty of acquisition, differentiation potential, immunogenicity and ethical risk. This makes it possible for umbilical cord derived mesenchymal stem cells to replace the most widely used bone marrow-derived and adipose tissue derived mesenchymal stem cells as the first choice for regenerating intervertebral discs. However, the survival of umbilical cord mesenchymal stem cells within the intervertebral disc is a major factor affecting their regenerative capacity. In recent years biomaterial scaffolds in tissue engineering have aided the survival of umbilical cord mesenchymal stem cells by mimicking the natural extracellular matrix. This seems to provide a new idea for the application of umbilical cord mesenchymal stem cells. This article reviews the structure of the intervertebral disc, disc degeneration, and the strengths and weaknesses of common treatment methods. We focus on the cell source, cell characteristics, mechanism of action and related experiments to summarize the umbilical cord mesenchymal stem cells and explore the feasibility of tissue engineering technology of umbilical cord mesenchymal stem cells. Hoping to provide new ideas for the treatment of disc degeneration.

Prediction of mechanistic subtypes of Parkinson’s using patient-derived stem cell models

Parkinson’s disease is a common, incurable neurodegenerative disorder that is clinically heterogeneous: it is likely that different cellular mechanisms drive the pathology in different individuals. So far it has not been possible to define the cellular mechanism underlying the neurodegenerative disease in life. We generated a machine learning-based model that can simultaneously predict the presence of disease and its primary mechanistic subtype in human neurons. We used stem cell technology to derive control or patient-derived neurons, and generated different disease subtypes through chemical induction or the presence of mutation. Multidimensional fluorescent labelling of organelles was performed in healthy control neurons and in four different disease subtypes, and both the quantitative single-cell fluorescence features and the images were used to independently train a series of classifiers to build deep neural networks. Quantitative cellular profile-based classifiers achieve an accuracy of 82%, whereas image-based deep neural networks predict control and four distinct disease subtypes with an accuracy of 95%. The machine learning-trained classifiers achieve their accuracy across all subtypes, using the organellar features of the mitochondria with the additional contribution of the lysosomes, confirming the biological importance of these pathways in Parkinson’s. Altogether, we show that machine learning approaches applied to patient-derived cells are highly accurate at predicting disease subtypes, providing proof of concept that this approach may enable mechanistic stratification and precision medicine approaches in the future.

A step toward stem cell engineering in vivo.

mRNA-based delivery may change the paradigm of hematopoietic stem cell gene therapy.

Molecular and Histological Changes in Airway Basal Stem Cells on Chronic Obstructive Pulmonary Disease

Airway basal stem cell changes in COPD including hyperplasia, squamous cell metaplasia, epithel-mesenchymal transision, impairment of cillia and secretoric non mucosal cell differentiation, and junctional barrier integrity disturbances that lead to histological changes. There are also molecular changes such as disturbances in gene expresion, cytokines, inflamation factor and dysregulation of basal cell transcriptome in locus 19q13.2. This article is aimed to review airway basal cell changes in COPD. By understanding initial changes of airway basal stem cell in COPD, hopefully can help to develop stem cell therapy in COPD treatment. The research aims to explore molecular and histological changes in airway basal stem cells on chronic obstructive pulmonary disease. The researchers used literature review as the way to verify their arguments on the issue discussed by analyzing the results of scientific sources, especially from trusted sources such as Google Scholar and Science Direct. The study continues by stating that regenerative therapy using stem cells has started to evolve with the advancement of stem cell technology and is anticipated to improve and treat this illness. Only preclinical and phase 2 clinical trials have seen recent advancements in the use of stem cells for treating COPD.

Bioprinted hASC-laden cell constructs with mechanically stable and cell alignment cue for tenogenic differentiation.

3D bioprinting is a technology that enables the precise and controlled deposition of cells and an artificial extracellular matrix (ECM) to create functional tissue constructs. However, current 3D bioprinting methods still struggle to obtain mechanically stable and unique cell-morphological structures, such as fully aligned cells. In this study, we propose a new 3D bioprinting approach that utilizes a high concentration of bioink without cells to support mechanical properties and drag flow to fully align cells in a thin bath filled with cell-laden bioink, resulting in a hybrid cell-laden construct with a mechanical stable and fully aligned cell structure. To demonstrate the feasibility of this approach, we used it to fabricate a cell-laden construct using human adipose stem cells (hASCs) for tendon tissue engineering. To achieve appropriate processing conditions, various factors such as the bioink concentration, nozzle moving speed, and volume flow rate were considered. To enhance the biocompatibility of the cell-laden construct, we used porcine decellularized tendon ECM.In vitrocellular responses, including tenogenic differentiation of the fabricated hybrid cell structures with aligned or randomly distributed cells, were evaluated using hASCs. In addition, the mechanical properties of the hybrid cell-laden construct could be adjusted by controlling the concentration of the mechanically reinforcing strut using methacrylated tendon-decellularized extracellular matrix. Based on these results, the hybrid cell-laden structure has the potential to be a highly effective platform for the alignment of musculoskeletal tissues.

Artificial Intelligence-Driven Diagnostic Systems for Early Detection of Diabetic Retinopathy: Integrating Retinal Imaging and Clinical Data

The global shortage of donor liver transplants poses a significant challenge to healthcare systems, with thousands of patients dying each year while on waiting lists This study examines the potential of technological liver transplantation 3D bioprinting and advanced stem cell technologies serve as solutions to address this important issue The goal was to create functional liver tissues that are complex structures of the natural liver and some of the important functions, and assess its viability as an alternative organ donor includes hepatocytes and other liver-specific cell types with an optimal pro-mesenchymal differentiation pattern stem cells ( MSCs). Research results showed that these compounds are capable of important liver functions such as liver function, urea excretion, pharmacokinetics, in vitro and in vivo conditions in addition to promising discovery together with early testing in animal models as a viable alternative that represents an important step towards biosynthetic implants.