Microphysiological systems to study tumor-stroma interactions in brain cancer

Effects of culture media on gene expression in reconstructed human epidermis and THP-1 monocytes for skin sensitization evaluation in co-culture systems

Co-culture with reconstituted epidermis formed by normal human epidermal keratinocytes (RhE) increases the expression of the skin sensitization markers CD54 and CD86 on the human monocytic leukemia cell line THP-1 without chemicals. Therefore, we investigated the effects of culture media [RPMI1640 for RhE; keratinization induction (KI) medium for THP-1], co-culture, and the responses to the skin sensitizer 2,4-dinitrochlorobenzene (DNCB) on gene expression in mono- and cocultures of RhE and THP-1 cells. Microarray and pathway analyses revealed that in mono-RhE, RPMI medium induced epidermal differentiation-related genes, whereas in monoculture THP-1 cells, KI medium upregulated inflammation-related genes. Surprisingly, the medium composition had a more significant impact than co-culture in both cells. However, crosstalk between RhE and THP-1 cells was observed upon DNCB exposure by comparing the differentially expressed gene sets. DNCB-treated THP-1 cells showed increased expression of NR4A1, NR4A2, NR4A3, SIK1, and HMOX1 in co-culture than in monoculture, and these gene expression patterns were confirmed by real-time RT-PCR. It has been suggested that danger signals from RhE, in response to DNCB, enhance the expression of these genes in THP-1 cells. We clarified the effects of the medium and co-culture and proposed these five genes as potential markers for skin sensitization evaluation.

Rapid Biofabrication of an Advanced Microphysiological System Mimicking Phenotypical Heterogeneity and Drug Resistance in Glioblastoma

Microphysiological systems (MPSs) reconstitute tissue interfaces and organ functions, presenting a promising alternative to animal models in drug development. However, traditional materials like polydimethylsiloxane (PDMS) often interfere by absorbing hydrophobic molecules, affecting drug testing accuracy. Additive manufacturing, including 3D bioprinting, offers viable solutions. GlioFlow3D, a novel microfluidic platform combining extrusion bioprinting and stereolithography (SLA) is introduced. GlioFlow3D integrates primary human cells and glioblastoma (GBM) lines in hydrogel-based microchannels mimicking vasculature, within an SLA resin framework using cost-effective materials. The study introduces a robust protocol to mitigate SLA resin cytotoxicity. Compared to PDMS, GlioFlow3D demonstrated lower small molecule absorption, which is relevant for accurate testing of small molecules like Temozolomide (TMZ). Computational modeling is used to optimize a pumpless setup simulating interstitial fluid flow dynamics in tissues. Co-culturing GBM with brain endothelial cells in GlioFlow3D showed enhanced CD133 expression and TMZ resistance near vascular interfaces, highlighting spatial drug resistance mechanisms. This PDMS-free platform promises advanced drug testing, improving preclinical research and personalized therapy by elucidating complex GBM drug resistance mechanisms influenced by the tissue microenvironment.

Hybrid-integrated devices for mimicking malignant brain tumors ("tumor-on-a-chip") for in vitro development of targeted drug delivery and personalized therapy approaches

Acute and requiring attention problem of oncotheranostics is a necessity for the urgent development of operative and precise diagnostics methods, followed by efficient therapy, to significantly reduce disability and mortality of citizens. A perspective way to achieve efficient personalized treatment is to use methods for operative evaluation of the individual drug load, properties of specific tumors and the effectiveness of selected therapy, and other actual features of pathology. Among the vast diversity of tumor types-brain tumors are the most invasive and malignant in humans with poor survival after diagnosis. Among brain tumors glioblastoma shows exceptionally high mortality. More studies are urgently needed to understand the risk factors and improve therapy approaches. One of the actively developing approaches is the tumor-on-a-chip (ToC) concept. This review examines the achievements of recent years in the field of ToC system developments. The basics of microfluidic chips technologies are considered in the context of their applications in solving oncological problems. Then the basic principles of tumors cultivation are considered to evaluate the main challengers in implementation of microfluidic devices, for growing cell cultures and possibilities of their treatment and observation. The main achievements in the culture types diversity approaches and their advantages are being analyzed. The modeling of angiogenesis and blood-brain barrier (BBB) on a chip, being a principally important elements of the life system, were considered in detail. The most interesting examples and achievements in the field of tumor-on-a-chip developments have been presented.