Biology subjects

Ceelen, W.

Publications and source records attributed to Ceelen, W..

3 recordsLinked to original sources

bioRxiv2026

Electrically Enhanced Intraperitoneal Drug Delivery Resolved by Fluorescence Lifetime Imaging Microscopy

Intraperitoneal delivery of nanoparticles (NPs) holds promise in the treatment of peritoneal metastases (PM), and the use of electric fields may enhance their tissue penetration. Evaluating NP delivery requires evidence of intracellular payload release, which is challenging in autofluorescent tissues. Here, we combined electromotive drug administration (EMDA) with cationic RL-100 NPs co-loaded with doxorubicin (DOX) and a near-infrared aza-BODIPY tracer, reporting carrier-associated distribution, while phasor fluorescence lifetime imaging microscopy (FLIM) characterized the molecular environment of DOX. In colorectal carcinoma, NP-delivered DOX progressed from cytoplasmic puncta to nuclear accumulation, while carrier-associated fluorescence remained cytoplasmic, supporting intracellular release. EMDA enhanced NP penetration in ex vivo human peritoneum and healthy rat peritoneum. In a syngeneic rat model of colorectal PM, both free and NP-delivered DOX remained detectable to approximately 1200 um after EMDA, compared with < 200 um after passive delivery. NP-delivered DOX remained detectable 24 h after EMDA. Whole-animal and ex vivo imaging showed the highest carrier-associated signals in tumor nodules and tumor-bearing omentum. These findings support electrically enhanced intraperitoneal delivery and a dual-reporter approach to evaluate carrier distribution, drug penetration, and intracellular release, with potential applications in other autofluorescent tissues. Together, these capabilities provide a preclinical basis for investigating NP-assisted delivery.

pharmacology and toxicology↗

bioRxiv2024

VSIG4-Expressing Macrophages Contribute To Anti-Parasitic And Anti-Metastatic Responses In The Peritoneal Cavity

Peritoneal tissue-resident macrophages, also referred to as large peritoneal macrophages (LPMs), play an important role as gatekeepers of peritoneal homeostasis by providing a first line of defense against pathogenic threats. About a third of the LPMs express the surface receptor V-set and Immunoglobulin domain containing 4 (VSIG4), but it is unclear to what extent these cells differ from their VSIG4-negative counterparts and perform dedicated functions. Here, we demonstrate that VSIG4+ LPMs, in contrast to VSIG4- LPMs, are in majority derived from embryonal precursors and their occurrence is to a large extent independent from sex and microbiota. Although their transcriptome and surface proteome are indistinguishable from VSIG4- LPMs at steady-state, VSIG4+ LPMs are superior in phagocytosing Gram-positive bacteria and colorectal carcinoma (CRC) cells. In-house generated anti-VSIG4 nanobody constructs that are antibody-dependent cell-mediated cytotoxicity (ADCC)-enabled allowed a selective elimination of the VSIG4+ LPM subset without affecting the overall LPM content of the peritoneal cavity. This strategy uncovered a role for VSIG4+ LPMs in lowering the first peak of parasitemia in a Trypanosoma brucei brucei infection model and in reducing the outgrowth of CRC cells in the peritoneal cavity, a prime metastatic site in CRC patients. Altogether, our data uncover a protective role for VSIG4+ LPMs in infectious and oncological diseases in the peritoneal cavity.

immunology↗

bioRxiv2019

Establishment and characterization of a cell line and patient-derived xenograft (PDX) from peritoneal metastasis of low-grade serous ovarian carcinoma

Peritoneal spread indicates poor prognosis in patients with serous ovarian carcinoma (SOC) and is generally treated by surgical cytoreduction and chemotherapy. Novel treatment options are urgently needed to improve patient outcome. Clinically relevant cell lines and patient-derived xenograft (PDX) models are of critical importance to therapeutic regimen evaluation. Here, a PDX model was established by orthotopic engraftment, subperitoneal tumor slurry injection, of low-grade SOC resulting in an early-stage transplantable peritoneal metastasis (PM)-PDX model. Histology confirmed the micropapillary and cribriform growth pattern with intraluminal tumor budding and positivity for PAX8 and WT1. PM-PDX dissociated cells show an epithelial morphotype with a 42h doubling time and 40% colony forming efficiency, they are insensitive to estrogen signaling, low sensitive to platinum derivatives and highly sensitive to paclitaxel (IC50: 6.3 {+/-} 2.2 nM, mean {+/-} SE). The patient primary tumor, PM, PM-PDX and derived cell line all show a KRAS c.35G>T (p.(Gly12Val)) mutation and show sensitivity to the MEK inhibitor trametinib in vitro (IC50: 7.2 {+/-} 0.5 nM, mean {+/-} SE) and in the PM mouse model. These preclinical models closely reflecting patient tumors are useful to further elucidate LGSOC disease progression, therapy response and resistance mechanisms.

cancer biology↗