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PhD discussions: Gülsun Bagci and Joana Admella
Friday, April 5 @ 10:00 am–11:00 am
Cell-Derived Extracellular Matrices for 3D in vitro Tumor Models
Gülsun Bagci, Biomaterials for Regenerative Therapies Group
Decellularized Extracellular matrices are new scaffolds for bioengineering of 3D tumor-ECM in vitro models. The tunable composition, properties, and structure of Cell-derived Matrices (CDMs) make them versatile and easy to use by using desired cell types. Moreover, deposition of ECM can be achieved by adding specific stimulants such as Macromolecular crowding (MMC) like Ficoll/dextran sulfate or treating with hypoxia/starvation. Our aim is to fabricate CDM by two strategies as 2D culture CDMs from human dermal fibroblasts (hDFs) or 3D culture CDM from bone marrow human mesenchymal stem cells (BM-hMSCs)/Human Adipose-derived stem cells (hAMSCs) in the presence of MMC/Ascorbic acid/ TGFβ-1 on Poly Lactic acid (PLA) derived microparticles (MPs) to generate 3D and 2D culture CDMs, which can be used as scaffold for reseeding cancer cells or used as bioinks to generate tumor models for cancer research and for testing anti-cancer drugs.
In this study, we generated 2D culture CDM from hDFs and 3D culture CDMs of BM-hMSCs and hAMSCs. To prepare 2D CDMs, hDF were treated with Ascorbic acid (AA) or Ficoll, AA, TGFβ-1 combination for 2-weeks to increase the deposition of CDM. To fabricate 3D culture CDM, cells were cultured into PLA MPs. MPs were produced by jet break-up method, and their size distribution was calculated by ImageJ whereas their porosity was imaged under SEM. Moreover, MPs were functionalized with fibronectin to enhance the cell adhesion. hMSCs/hAMSCs were seeded on MPs in a spinner flask for 8 hours. Then, cell-seeded MPs were cultured for 2 weeks to produce CDM. The cellular viability and cell seeding in the MPs were evaluated. The ECM production before and after decellularization was evaluated by BCA, hydroxyproline, SEM, qRT-PCR, and immunofluorescence. Values were normalized by the total DNA. Microtissues and cells on 2D culture were also decellularized with 50mM NH4OH, 0.05% TritonX-100 solution and characterized.
Based on our results, for hDF cells; Ficoll, TGFβ-1 and Ascorbic acid combination, and also ascorbic acid alone treatments increased total protein and total collagen production. For BM-hMSCs, total collagen and protein after 2-weeks incubation was increased significantly in the presence of Ascorbic acid condition on the fibronectin coated MPs. AA increased total protein and total collagen production for hAMSCs at 3D culture.
CDMs are promising and tunable biomaterials to establish 3D in vitro tumor models for cancer research. This platform possess a powerful potential for testing anti-cancer drugs for personalized medicine in the coming years.
Exploring the potential of Galleria mellonella for the study of bacterial infections
Joana Admella, Bacterial Infections: Antimicrobial Therapies Group
Bacterial infections are becoming more threatening every day. Pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, Mycobacterium abscessus, or Burkholderia cenocepacia pose significant challenges due to antimicrobial resistance. Our group has extensive experience in studying pathogenic microorganisms, with a focus on understanding bacterial virulence and biofilm formation.
The insect Galleria mellonella is an alternative animal model widely used for studying bacterial infections and evaluating the toxicity of various molecules and materials. It presents a wide range of advantages, including low cost, easy maintenance, and lack of ethical constraints. Furthermore, very precise doses can be injected, facilitating the testing of diverse treatments like antibiotics, nanomedicines, or even bacteriophages. Notably, their innate immune system closely resembles that of mammals, encompassing both cellular and humoral defenses. These features make Galleria mellonella a very valuable model for investigating host-pathogen interactions, infection dissemination, and immune response. Here, we present an overview of this animal model, showing a variety of methodologies and applications that have enhanced our understanding of bacterial infections and expanded our knowledge of this insect.
