Biology subjects

Lozano, N.

Publications and source records attributed to Lozano, N..

3 recordsLinked to original sources

bioRxiv2023

Engineering the glioblastoma microenvironment using TLR7/8 agonist-complexed graphene oxide nanosheets

The glioblastoma (GBM) microenvironment is characterised as immunologically cold, with immunosuppressive components that compromise the efficacy of current immunotherapies. Tumour associated macrophages and microglia (TAMMs) that are activated towards an immunosuppressive, pro-tumoral state have been identified as major contributing factors to the coldness of GBM, while further promoting tumour progression and resistance to therapy. Based on this understanding, strategies such as macrophage reprogramming have been explored but have so far been limited by poor delivery and retention of reprogramming agents to the target cell populations within the GBM microenvironment. Consequently, clinical efficacy of such approaches has thus far shown limited success. Two-dimensional, graphene oxide (GO) nanosheets have been demonstrated to spread readily throughout the entire tumour microenvironment following a single intratumoral injection, interacting primarily with TAMMs. The current study aimed to investigate whether the immunosuppressive character of TAMMs in GBM can be ameliorated using GO sheets as a vector system to selectively deliver a TLR7/8 agonist (Resiquimod, R848), into these populations. GO enhanced the activity of R848 and induced the expression of M1-like markers on bone marrow derived macrophages in vitro. Using multi-parameter flow cytometry and histological analysis in a syngeneic, orthotopic mouse model of GBM, we observed that a single intratumoral injection of GO:R848 complex significantly elevated the proportion of macrophages and microglia expressing MHCII, TNF and CD86 (associated with a pro-inflammatory, anti-tumoral state), while downregulating their expression of the M2 markers ARG1 and YM1 (associated with an anti-inflammatory, pro-tumoral state). This local complex administration inhibited tumour progression and significantly reduced tumour burden. These data illustrate that immunomodulatory GO nanosheets can effectively alter the immune landscape of GBM and modulate the wider GBM microenvironment. ToC Image O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=126 SRC="FIGDIR/small/558196v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@199bdb0org.highwire.dtl.DTLVardef@7473c3org.highwire.dtl.DTLVardef@15c14c6org.highwire.dtl.DTLVardef@57fdeb_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2023

Engineering of a graphene oxide-based two-dimensional platform for immune activation and modulation

Nanoscale-based tools for immunomodulation are expected to offer a rich battery of options for more targeted and safer approaches to achieve clinically effective manipulation of the local and systemic immune environment. In this study, we aimed to design nanoscale constructs based on graphene oxide (GO) nanosheets as platform carriers for the TLR7/8 agonist Resiquimod (R848). The non-covalent complexation of R848 molecules on the GO surface resulted in stable complexes by preserving their biological activity. The physicochemical properties, molecular quantification, as well as the overall performance of the complex were systematically investigated. We hypothesized the formation of GO:drug nano-constructs with strong colloidal stability over time, due to the strong {pi}-{pi} interactions between the R848 molecules and the GO surface, and identified that R848 loading efficiency consistently ranged around 75% (of starting molecules), quantified by HPLC and UV-Vis. The 2D morphology of the thin nanosheets was retained after complexation, determined by various (AFM and SEM) microscopic techniques. Based on the surface physicochemical characterization of the complexes by Raman, FTIR, XPS, and XRD, the formation of non-covalent interactions among the GO surface and the R848 molecules was confirmed. Most importantly, GO:R848 complexes did not compromise the biological activity of R848, and effectively activated macrophages in vitro. Collectively, this study demonstrates that thin GO sheets can act as platforms for the non-covalent association with small TLR7/8 agonist molecules, forming stable and highly reproducible complexes, that could be exploited as effective immunomodulatory agents.

bioengineering↗

bioRxiv2023

Functioning human lung organoids model pulmonary tissue response from carbon nanomaterial exposures

Human lung organoids (HLOs) are increasingly used to model development and infectious diseases, however their ability to recapitulate functional pulmonary tissue response to nanomaterial (NM) exposures has yet to be demonstrated. Here, we established a lung organoid exposure model that utilises microinjection to present NMs into the lumen of organoids. Our model assures efficient, reproducible and controllable exposure of the apical pulmonary epithelium, emulating real-life human exposure scenario. By comparing the impact of two well studied carbon-based NMs, graphene oxide sheets (GO) and multi-walled carbon nanotubes (MWCNT), we validated lung organoids as tools for predicting pulmonary NM-driven responses. In agreement with established in vivo data, we demonstrate that MWCNT, but not GO, elicit adverse effects on lung organoids, leading to a pro-fibrotic phenotype. Our findings reveal the capacity and suitability of HLOs for hazard assessment of NMs, aligned with the much sought-out 3Rs (animal research replacement, reduction, refinement) framework.

pharmacology and toxicology↗