Bilge Alptekin, İbrahim Alptekin, Ezel Erkan, Ferda Topal Celikkan, Alp Can
{"title":"Stepwise Optimization of a Matrigel-Based In Vitro Angiogenesis Assay for Reproducible and Quantifiable 2D-Tube Formation Using HUVECs.","authors":"Bilge Alptekin, İbrahim Alptekin, Ezel Erkan, Ferda Topal Celikkan, Alp Can","doi":"10.1007/7651_2026_709","DOIUrl":"10.1007/7651_2026_709","url":null,"abstract":"<p><p>This chapter presents a stepwise optimization of a Matrigel<sup>®</sup>-based in vitro angiogenesis assay using human umbilical vein endothelial cells (HUVECs) to achieve reproducible and quantifiable tube formation. Critical parameters-including culture surface, matrix composition and thickness, coating temperature and incubation time, growth factor-defined serum-free medium, and cell seeding density-were systematically evaluated. Optimal conditions were identified as 3 mg/mL Matrigel (100 μL/well), polymerized at 22 °C for 90 min, with HUVECs seeded at 20,000 cells/cm<sup>2</sup> and cultured in a defined growth factor cocktail. Standardized imaging and ImageJ-based analysis enabled robust quantification of network features. This protocol improves consistency, stability, and comparability across angiogenesis studies.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148016459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quantifying Mechanical Properties of Fresh Ovarian Tissue with Optical Brillouin Microscopy.","authors":"Shahrin Jahan Jaima, Mankirat Singh, Saumya Nigam, Zexu Jiao, Ping Wang, Jitao Zhang","doi":"10.1007/7651_2026_710","DOIUrl":"https://doi.org/10.1007/7651_2026_710","url":null,"abstract":"<p><p>Mechanical properties play a critical role in regulating ovarian function, yet their spatial variation within intact tissue remains poorly understood due to the limitations of conventional mechanical testing techniques. Confocal Brillouin microscopy offers a non-contact and label-free approach for mapping mechanical properties of the intact ovarian tissue without perturbing tissue structure. In fresh ovarian tissue, Brillouin images reveal spatial heterogeneity in mechanical properties across follicles, surrounding stroma, and fluid-filled regions, suggesting underlying differences in cellular organization and extracellular matrix composition. These measurements capture both inter- and intra-follicular variations, providing insight into regional differences in mechanical properties within and between follicles. This chapter outlines the principles of Brillouin microscopy and its application to fresh ovarian tissue, highlighting its capability to resolve microscale mechanical variations in situ. This method provides a foundation for understanding the role of mechanical properties in ovarian function, with potential applications in disease models and reproductive health research.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148016457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A High-Content Screening Workflow for Pancreatic Cancer Therapy Development Using Patient-Derived Tumor Organoid Cohorts: An Adaptation to Enable In Organoid Synergistic Drug Discovery.","authors":"Meritxell B Cutrona","doi":"10.1007/7651_2026_698","DOIUrl":"https://doi.org/10.1007/7651_2026_698","url":null,"abstract":"<p><p>Identifying therapies with potential clinical relevance is a critical task for intervening on pancreatic ductal adenocarcinoma (PDAC), the most common pancreatic malignancy, characterized by an extremely poor prognosis and expected to be among the most prevalent lethal tumors in the coming years. Unified therapeutic options are limited because PDAC tumors are complex at the genomic, epigenetic, and metabolic levels, often involving multiple and interacting pathways orchestrated by undruggable drivers. Inter-patient heterogeneity in drug response, accompanied by high recurrent rates of chemoresistance, makes PDAC an almost incurable tumor by pharmacological means. Resource-intensive approaches need to be implemented in order to identify effective therapies along the integration of PDAC tumor heterogeneity landscape. Large-scale technologies such as high-content screening (HCS) hold promise to uncover novel cures, especially when therapy response interrogation involves the incorporation of highly physiological-competent human PDAC models such as collections of patient-derived tumor organoids (PDOs). However, systematic and unbiassed drug combination-HCS applied directly on PDOs, intended to ensure the detection of effective pairs or multidrug combinations to preclinically inform on effective drug combinatorial regimens, is still missing. This chapter proposes a PDO-guided drug-synergy image-based HCS pipeline already implemented in a proof-of-concept study for PDAC therapy development, design and validation of drug-synergy screening, using collections of PDOs.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147931101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Riho Kanai, Arvind Hariharan, Janaki Iyer, Younan Liu, Takashi I, Yoshinori Sumita, Simon D Tran
{"title":"Tracking of Transplanted Stem Cells in Mouse Models Using Practical Fluorescence-Based Protocols.","authors":"Riho Kanai, Arvind Hariharan, Janaki Iyer, Younan Liu, Takashi I, Yoshinori Sumita, Simon D Tran","doi":"10.1007/7651_2026_704","DOIUrl":"https://doi.org/10.1007/7651_2026_704","url":null,"abstract":"<p><p>Precise tracking of transplanted cells within mouse tissues is essential for evaluating engraftment, migration, and long-term persistence in transplantation and regenerative medicine research. Here, we present a practical and versatile cell-tracking workflow focusing on PKH26-based direct fluorescent labeling and GFP-mediated indirect genetic labeling. PKH26 provides rapid and robust membrane labeling that is useful for short-term tracing, while GFP enables stable and heritable fluorescence suitable for long-term monitoring of transplanted cells. This chapter provides optimized protocols, troubleshooting strategies, and critical technical considerations for implementing these complementary methods. Together, these approaches offer a flexible and reliable framework for evaluating the engraftment, survival, distribution, and behavior of transplanted cells in mouse models.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147839932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gözde Özsezer, Berk Deniz Tosunoğlu, Yavuz Emre Arslan
{"title":"A Review on Nanotoxicology in Stem Cell Research: Challenges and Safety Assessments.","authors":"Gözde Özsezer, Berk Deniz Tosunoğlu, Yavuz Emre Arslan","doi":"10.1007/7651_2026_705","DOIUrl":"https://doi.org/10.1007/7651_2026_705","url":null,"abstract":"<p><p>This review presents a balanced synthesis of the efficacy-nanotoxicity window of nanomaterials-including carbon-based structures, metallic nanoparticles, and bioceramic composites-within the context of stem cell-assisted tissue engineering. It emphasizes that increases in conventional differentiation markers may not necessarily correspond to functional maturity or long-term safety. Therefore, a gradual shift from standard viability-based assays toward lineage-specific functional assessments is discussed. The nanotoxicological profile of these materials is examined across major tissue types, highlighting how similar physicochemical properties may yield beneficial or adverse outcomes depending on concentration, exposure time, and microenvironmental conditions. In bone tissue, the review considers the point at which enhanced mineralization may be accompanied by oxidative stress and mitochondrial strain. For cartilage, potential concerns related to ion and degradation product accumulation in avascular environments are addressed, including the possible induction of inflammatory signaling and hypertrophic markers such as collagen type X. In neural and cardiac applications, efforts to improve electrical conductivity are evaluated alongside potential electrophysiological alterations, including Ca<sup>2+</sup> imbalance and rhythm disturbances at sub-cytotoxic levels. Vascular differentiation is discussed within the context of pro-angiogenic signaling and the risk of endothelial dysfunction. By comparing experimental systems ranging from 2D cultures to induced pluripotent stem cell (iPSC)-derived organoids, the review underscores the model-dependent and tissue-specific nature of nanotoxic responses. Overall, it outlines considerations for integrating physicochemical characterization with functional and metabolic endpoints to support more reliable evaluation of nanobiomaterials in regenerative medicine.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147840021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Theebah Sellathurai, Frédéric Auvré, Fabienne Bloas, Stéphane Commo, Gilles Lemaître, Nicolas O Fortunel
{"title":"Isolation of Keratinocytes from Human Hair Follicles and Selection of a Population Enriched in Epithelial Stem and Progenitor Cells by Flow Cytometry.","authors":"Theebah Sellathurai, Frédéric Auvré, Fabienne Bloas, Stéphane Commo, Gilles Lemaître, Nicolas O Fortunel","doi":"10.1007/7651_2026_703","DOIUrl":"https://doi.org/10.1007/7651_2026_703","url":null,"abstract":"<p><p>The human hair follicle (HF) harbors distinct populations of epithelial stem and progenitor cells that are essential for hair homeostasis and epidermal wound healing. While the follicular niche, the anatomical equivalent of the murine bulge located at the insertion site of the arrector pili muscle, has historically been the primary target for the isolation of hair follicle stem cells (HFSCs), capturing the full epithelial stem and progenitor hierarchy within the outer root sheath (ORS) is critical for a comprehensive understanding of human hair follicle biology. As integrin α6 (CD49f) is a well-established surface marker associated with basal epithelial stem and progenitor states, and long-term proliferative potential of immature keratinocytes, we have exploited this marker to isolate an epithelial cell population corresponding to the keratinocyte basal layer of the ORS. This chapter describes a protocol for the enrichment of stem and progenitor cells from intact human hair follicles, combining manual microdissection of the entire hair follicle, enzymatic dissociation, and flow cytometry sorting based on CD49f expression.Functional validation using in vitro proliferation and clone-forming assays showed that the CD49f<sup>high</sup> fraction exhibits significantly greater proliferative and clonogenic capacity, compared to the ORS total and CD49f<sup>low</sup> populations. This method preserved cell viability and phenotypic integrity. Consequently, the isolated keratinocyte populations are suitable for a broad range of downstream uses and applications, including transcriptomic analyses such as single-cell RNA sequencing (scRNA-seq), functional assays, and regenerative studies. Altogether, this workflow provides a robust platform for future approaches dedicated to the treatment of alopecia, promotion of hair longevity, and for tissue engineering applications.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147840055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fabrication and Biological Evaluation of 3D Bioprinted GelMA Scaffolds with Bone Marrow-Derived Mesenchymal Stem Cells for Osteochondral Tissue Engineering.","authors":"Reyhan Yanikoglu, Elif Balikci, Ayse Ceren Calikoglu-Koyuncu","doi":"10.1007/7651_2026_707","DOIUrl":"https://doi.org/10.1007/7651_2026_707","url":null,"abstract":"<p><p>Repairing osteochondral defects remains a significant therapeutic challenge due to the complex hierarchical structure of the tissue, while existing treatment strategies are largely palliative rather than curative. For osteochondral tissue production, three-dimensional (3D) bioprinting has become a potent technique to produce biomimetic scaffolds with regulated architecture and cell distribution. This chapter provides a comprehensive and repeatable procedure for the production and biological assessment of 3D bioprinted gelatin methacryloyl (GelMA) scaffolds that incorporate mesenchymal stem cells (MSCs) obtained from bone marrow. The methodology outlines the techniques for photo-crosslinking, extrusion-based bioprinting, MSC expansion and encapsulation, and bioink preparation in order to guarantee cell viability and structural integrity. Comprehensive in vitro evaluation techniques are also described, such as differentiation evaluation related to osteogenic and chondrogenic commitment, cell viability, and proliferation analysis. This methodical approach offers researchers a useful foundation for creating MSC-laden GelMA constructs appropriate for use in osteochondral tissue engineering and additional translational studies.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147840064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mehmet Bozdag, Zehra Kanli, Oguzhan Gunduz, Sumeyye Cesur
{"title":"Sequential DLP Bioprinting of Dual-Layered Brain Organoid-Like Neural Microtissues Using Nanocomposite Bioinks.","authors":"Mehmet Bozdag, Zehra Kanli, Oguzhan Gunduz, Sumeyye Cesur","doi":"10.1007/7651_2026_706","DOIUrl":"https://doi.org/10.1007/7651_2026_706","url":null,"abstract":"<p><p>This chapter provides a detailed, step-by-step protocol for the fabrication of architecturally defined brain organoid-like neural microtissues using a sequential digital light processing (DLP) bioprinting strategy. The method relies exclusively on DLP technology to fabricate complex heterogeneous structures through a layer-by-layer vat-switching technique. Central to this protocol is the formulation of a nanocomposite bioink, where reduced graphene oxide (rGO) nanoparticles and bacterial cellulose are mixed with gelatin methacryloyl (GelMA) matrix. This composition provides enhanced electrical conductivity, printability, and mechanical stability, promoting neural network maturation. We describe the complete workflow from induced pluripotent stem cell (iPSC) culture and neural induction, through bioink preparation and DLP printing parameter optimization, to long-term static culture and functional validation. This protocol addresses key limitations of conventional self-assembly methods, offering improved reproducibility, structural control, and physiological relevance for modeling neurodevelopment and disease.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147839856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meryem Akkurt Yildirim, Hanife Sevgi Varli, Cem Bülent Üstündağ
{"title":"Generation of Induced Pluripotent Stem Cells from Somatic Cells via Solid Lipid Nanoparticle-Mediated Plasmid DNA Delivery.","authors":"Meryem Akkurt Yildirim, Hanife Sevgi Varli, Cem Bülent Üstündağ","doi":"10.1007/7651_2026_708","DOIUrl":"https://doi.org/10.1007/7651_2026_708","url":null,"abstract":"<p><p>Induced pluripotent stem cells (iPSCs) have enabled significant advances in regenerative medicine; however, reprogramming methods using viral vectors pose risks to safety and genomic integrity in clinical applications. This protocol details a non-viral, integration-free approach for delivering plasmid DNA (pDNA) into somatic cells via solid lipid nanoparticles (SLNs). SLNs protect pDNA from enzymatic degradation and ensure high transfection efficiency in cells, thereby preventing permanent genetic alterations in the host genome.The protocol provides step-by-step guidance for the preparation of human fibroblasts, the sequential transcription cycles of SLN-pDNA encoding OSKM factors, and the induction and isolation of iPSC colonies. Furthermore, comprehensive characterization methods are described to confirm pluripotency, including monitoring GFP expression levels, quantitative real-time PCR, immunofluorescence staining, flow cytometry, alkaline phosphatase activity assays, and in vitro tri-lineage differentiation.iPSCs obtained while preserving genomic integrity can be safely used in advanced regenerative medicine applications, such as disease modeling, high-throughput drug screening, and personalized cell therapies. This approach enhances safety and efficacy in clinical settings and provides a valuable platform for the development of iPSC-based therapeutic and research applications.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147840140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Live-Cell Imaging of Fish Epidermal Keratocytes.","authors":"Chika Okimura, Yoshiaki Iwadate","doi":"10.1007/7651_2026_702","DOIUrl":"https://doi.org/10.1007/7651_2026_702","url":null,"abstract":"<p><p>Fish epidermal keratocytes provide a powerful model system for investigating cell motility due to their rapid, persistent migration and stable morphology. While single-cell dynamics have been extensively characterized, recent studies have increasingly focused on collective migration. Because keratocytes cannot be maintained as continuous cell lines, experiments rely on primary cultures derived from fish scales. This chapter presents optimized protocols for culturing primary keratocytes, transiently introducing fluorescent probes using a custom electroporation system and performing high-resolution three-dimensional time-lapse imaging with confocal microscopy. These procedures enable visualization of dynamic molecular and cellular behaviors in both single-cell and collective migration contexts.</p>","PeriodicalId":18490,"journal":{"name":"Methods in molecular biology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147775879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}