Biology subjects

Khorsandi, D.

Publications and source records attributed to Khorsandi, D..

3 recordsLinked to original sources

bioRxiv2025

Modeling Immunosenescence on-a-chip: a platform for cancer vaccine efficacy assessment

Immunosenescence dramatically reduces cancer vaccine efficacy in elderly patients, who represent the majority of cancer cases. Despite this clinical reality, age-related immune decline is rarely considered in preclinical testing. Therefore, novel in vitro models to test cancer vaccine efficacy, considering immunosenescence, are needed. Our novel lymph node paracortex on-a-chip (LNPoC) platform addresses this gap by recapitulating age-dependent immune responses against cancer vaccines, specifically antigen presentation, antigen-specific T cell activation, and antitumoral responses. Using this platform, we demonstrated that bone marrow-derived antigen-presenting cells (APCs) from young mice (6-7 weeks) displayed significantly enhanced ovalbumin (OVA) peptide presentation compared to APCs from older mice (35-36 weeks). This age-dependent difference translated to significantly greater OVA-specific CD8+ T cell activation and increased cytotoxicity against B16-OVA cancer cells. These age-dependent differences are unique to our LNPoC and undetectable in traditional 2D cultures, confirming that our LNPoC was more effective than 2D cultures at recapitulating immunosenescence-mediated immune responses against cancer vaccines in vitro. The in vivo validation confirms these findings, as young mice demonstrated higher OVA-specific CD8+ T cell responses and smaller tumors than older mice. Our LNPoC is a valuable tool for assessing immunosenescences impact on cancer vaccines, potentially guiding more effective therapies for older adults.

bioengineering↗

bioRxiv2025

Embolization-on-a-chip: Novel Vascularized Liver Tumor Model for Evaluation of Cellular and Cytokine Response to Embolic Agents

BackgroundEmbolization is a well-established treatment modality for liver cancer. However, traditional embolization agents are limited by inefficient delivery and aggregation in blood vessels. Novel shear-thinning hydrogels (STH) have been developed to address the need for safer and more effective local delivery of embolic agents and therapeutics. ObjectiveWe aim to evaluate the efficacy of novel embolic agents such as STH using a human-relevant in vitro model that recapitulates human hepatocellular carcinoma capillary networks. MethodsA vascularized human liver-tumor-on-a-chip model was developed to assess embolic agent performance. The effects of drug-eluting STH (DESTH) on tumor cell viability, surface marker expression, vasculature morphology, and cytokine responses were evaluated. To study the effects of embolization on microvasculature morphology independent of the chemotherapy compound, we assessed the effect of different drug-free embolic agents on the vascular tumor microenvironment under flow conditions. ResultsDESTH treatment induced tumor cell death, downregulated the expression of Epithelial Cell Adhesion Molecules (EpCAM) in HepG2, increased levels of cytokines such as Interleukin-4 (IL-4), Granulocyte-macrophage colony-stimulating factor (GM-CSF), and Vascular Endothelial Growth Factor (VEGF), and decreased albumin secretion. Furthermore, different embolic agents exert distinct effects on microvascular morphology, with STH causing complete regression of the microvascular networks. ConclusionThis vascularized liver tumor-on-a-chip model enables human-relevant, real-time assessment of embolic agent efficacy and vascular response, paving the way for the development of innovative and effective embolization therapies for liver cancer.

bioengineering↗

bioRxiv2024

Microphysiological system modeling pericyte-induced temozolomide resistance in glioblastoma

Glioblastoma (GBM) is a malignancy with poor survival and high rates of chemoresistance. Temozolomide (TMZ), the standard-of-care chemotherapy for GBM patients, but GBM cells can be resistant to TMZ, resulting in limited clinical efficacy. Elucidating the complex mechanisms of TMZ chemoresistance in GBM requires novel in vitro models replicating the complex tumor microenvironment (TME). We present an multicellular 3D GBM model recapitulating the biomechanical characteristics of brain tissues and pericyte-mediated TMZ resistance. The composite hydrogel used to encapsulate GBM spheroids (U87, LN229, and PDM140), pericytes, or GBM spheroids with pericytes, mimics the rheological properties of brain tissues (G[~]800Pa and G"[~]100Pa). When untreated, the GBM models remain viable and proliferative for 14 days. PDM140 spheroids were most sensitive to TMZ (IC50=73M), followed by LN229 (IC50=278M) and U87 (IC50=446M). With pericytes, the viability of TMZ-treated GBM spheroids significantly increases by 22.7% for PDM140, 32.5% for LN229, and 22.1% for U87, confirming pericyte-induced GBM chemoresistance responses. The upregulation (380-fold) of C-C motif chemokine ligand 5 (CCL5) in pericytes upon TMZ treatment could explain the chemoresistance responses. This innovative brain-mimicking 3D GBM model represents a novel in vitro platform for testing the efficacy of TMZ and novel drugs targeting CCL5-mediated chemoresistance pathways in GBM.

bioengineering↗