Hosseini, S. A. | bioRxiv Science

bioRxiv2024

A hybrid bioprinting-electrospinning platform integrating nanofibers and mesenchymal cell spheroids for customizable wound healing dressings

We introduce a platform for the fabrication of customizable wound healing dressing. The platform integrates electrospun nanofibers, bioprinted hydrogels, and cellular spheroids into hierarchical, fiber-reinforced hybrid constructs. The construct leverages the mechanical strength of polycaprolactone (PCL) nanofibers and the ECM-like properties of GelMA/PEGDA hydrogel. These materials support the incorporation of bone marrow-derived mesenchymal stem cell (BM-hMSC) spheroids, which act as a supportive "cell niche," enhancing the viability of the hMSC during and after bioprinting, and facilitating their spreading across the construct during the maturation phase. The characterization of the hybrid constructs demonstrated strong structural integrity and enhanced mechanical properties, making them well-suited for clinical wound dressing applications. In vitro assays, including live/dead staining, MTT assays, and scratch assays, revealed increased cell attachment, proliferation, and migration. The spheroids maintained their viability over extended periods, significantly contributing to wound closure in the scratch assay. This innovative approach, which combines electrospinning and light-based bioprinting, offers a promising strategy for the development of customizable wound dressings that closely adapt to the complex architecture of human skin. The bioprinting approach allows for the creation of tailored geometries for specific clinical requirements. Future research will focus on optimizing scaffold design and conducting long-term in vivo studies to validate the platforms clinical potential.

cell biology↗

bioRxiv2023

Controlled tumor heterogeneity in a co-culture system by 3D bio-printed tumor-on-chip model

BackgroundCancer treatment resistance is a consequence of cell diversity and tumor heterogeneity. Tumor cell-cell and cell-microenvironment interactions significantly influence tumor progression and invasion, which have important implications for diagnosis, therapeutic treatment and chemoresistance. MethodIn this study, we develop 3D bioprinted in vitro models of the breast cancer tumor microenvironment (TME) made of co-cultured cells distributed in a hydrogel matrix with controlled architecture to model tumor heterogeneity. We hypothesize that the tumor could be represented by a cancer cell-laden co-culture hydrogel construct, whereas its microenvironment can be modeled in a microfluidic chip capable of producing a chemical gradient. Breast cancer cells (MCF7 and MDA-MB-231) and non-tumorigenic mammary epithelial cells (MCF10) were embedded in the alginate-gelatine hydrogels and printed using a multi-cartridge extrusion bioprinter. ResultsOur method gives special control on the cell positions in the co-culture system, whereas different tumor architectures can be designed. Cellularly heterogeneous samples comprised of two different cancer cells with controlled density are developed in specific initial locations, i.e. two cell types randomly mixed or positioned in sequential layers. A migration-inducing chemical microenvironment was created in a chamber with a gradual chemical gradient to study the cell migration in the complex tumor construct toward the chemoattractant. As a proof of concept, the different migration pattern of MC7 cells toward the epithelial growth factor gradient was studied with presence of MCF10 in different ratio in this device. ConclusionCombining 3D bioprinting with microfluidic device in our method provides a great tool to create different tumor architectures as can be seen in different patients, and study cancer cells behaviour with accurate special and temporal resolution.

bioengineering↗