Biology subjects

Wilm, B.

Publications and source records attributed to Wilm, B..

17 recordsLinked to original sources

bioRxiv2026

Assessing the efficacy of human mesenchymal stromal cells of different tissue origins in a mouse model of kidney ischaemia reperfusion injury

Rodent models of kidney disease have been widely used to assess the efficacy, safety and mode of action of mesenchymal stromal cells (MSCs) as therapies. However, because kidney disease models, MSC type and the methods used to assess kidney injury tend to differ between research groups, it is difficult to obtain data that are sufficiently robust and reproducible to support clinical translation. We present here for the first time a side-by-side analysis of the performance of human MSCs derived from the most commonly used tissue sources, bone marrow (BM-), adipose- (A-) and umbilical cord (UC-), in a kidney ischaemia reperfusion injury (IRI) model in mice. For each animal, we performed a comprehensive assessment of kidney function and health by longitudinal transdermal measurements of sinistrin clearance, serum biomarker levels at the experimental endpoint, and histopathological scoring of sections from left and right kidneys. Furthermore, we tracked the MSCs by bioluminescence imaging in the injured mice to determine their viability over time and their capacity for homing to the damaged kidneys. Our results reveal that only modest if any beneficial effects of the MSC treatments were detectable on kidney function and histology, irrespective of cell type administered. Furthermore, all three MSC types were sequestered in the lungs without reaching the kidneys, and had completely disappeared within 7 days. Our data suggest that none of the MSC types has the capability to improve renal health following IRI to a meaningful extent, questioning their suitability as a clinical therapy. Significance StatementMSCs have been proposed as efficacious cell therapies in murine models of kidney disease, with potential for clinical translation. We compare efficacy of human MSCs of different tissue origins (adipose, bone marrow and umbilical cord) in a refined mouse model of renal IRI. Only modest if any beneficial effects on kidney function and histology were detectable for all three cell types, and cells did not reach the kidneys but sequestered in the lungs where they died.

physiology↗

bioRxiv2025

Modelling Glomerular Filtration using Multispectral Optoacoustic Tomography and a Novel Near-infrared Dye

Kidney disease carries significant morbidity, mortality, and financial cost. Preclinical work exploring more accurate methods for assessing renal function is key for monitoring disease progression and the efficacy of future therapies. Measuring kidney function by dynamic contrast enhanced imaging allows us to measure left and right kidney function separately. This provides an internal control where a unilateral injury model is used. Multispectral optoacoustic tomography (MSOT) can measure the renal clearance of administered near infrared absorbers and, via the application of mathematical models, allows for the calculation of glomerular filtration rate. ABZWCY-HP{beta}CD is a cyanine dye bound to 2-hydroxylpropyl-{beta}-cyclodextrin and has shown promise as a glomerular filtration marker. Here we combine MSOT, ABZWCY-HP{beta}CD, and a modified Patlak-Rutland model to measure the glomerular filtration rate of healthy mice and following ischaemic reperfusion injury.

physiology↗

bioRxiv2025

Compound design of a patient-derived 3D cell culture system modelling early peritoneal endometriosis

Peritoneal endometriosis causes pelvic pain and infertility, but the underlying mechanisms related to these symptoms are not fully understood. Endometriosis diagnosis is typically delayed; thus, patient samples are unsuitable to study early endometriosis formation in situ. This study aimed to generate a 3D co-culture model of early peritoneal endometriosis using patient-derived primary cells, providing unique opportunities to examine endometriotic lesion initiation and progression. Peritoneal wash fluid, fallopian tube mesentery and endometrial biopsies were collected from patients undergoing laparoscopic surgery to isolate primary cells. A composite 3D hydrogel construct was assembled by embedding human peritoneal fibroblasts (HPFs) in a Matrigel-collagen I matrix and subsequent seeding with a layer of human peritoneal mesothelial cells (HPMCs). Immunohistological investigation of the composite hydrogel construct confirmed the successful assembly of a simple peritoneum layer model comprising a mesothelial monolayer, basement membrane and underlying fibroblasts, while secretion of tissue plasminogen activator demonstrated functional mesothelial physiology. Endometrial epithelial organoids (EEOs) were co-cultured with endometrial stromal cells (ESCs) to form endometrial assembloids mimicking shed endometrial tissue fragments at menstruation. When transplanted onto the peritoneal layer model, endometrial assembloids adhered, thus simulating early endometriotic lesion formation. Histological analysis demonstrated direct cell-cell contacts between HPMC, HPF and ESC at the endometrial-peritoneal interface, suggesting the involvement of those cell types in lesion initiation. Our modifiable superficial endometriosis model allows for further refinement by the addition of hormones, cytokines and/or other cell types to determine the underlying molecular mechanism involved in endometriotic lesion formation. HighlightO_LISimple peritoneal layer model resembles parietal peritoneum structure and function. C_LIO_LICombined endometrial and peritoneal model mimics early endometriosis formation. C_LIO_LIThe patient-derived multi-cellular model is suitable to study early endometriosis. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/643554v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@8e0639org.highwire.dtl.DTLVardef@3ab7a7org.highwire.dtl.DTLVardef@ef6e81org.highwire.dtl.DTLVardef@13fe704_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2024

Dynamic Wt1 expression in the gastrulation-stage mouse embryo specifies vascular and visceral smooth muscle cell fate independently from mesothelial fate.

1.The Wilms Tumour protein (WT1) was previously linked to the mesothelial and vascular smooth muscle cell (vSMC) lineage in the mouse intestine, with evidence suggesting that intestinal vSMCs arise from the mesothelium. Here, we report that WT1 is already expressed, unexpectedly, during gastrulation, in cells that specify a population of SMC precursor cells in the lateral plate mesoderm (LPM). Tamoxifen-induced genetic lineage tracing of Wt1-expressing cells revealed that vSMC and visceral smooth muscle cells (visSMCs) of the foetal mid-gut, but not mesothelial cells, were labelled after Tamoxifen administration at E7.5 or E8.5. Analysis of single cell RNA sequencing (scRNAseq) datasets of gastrulation-stage mouse embryos and confocal microscopy demonstrated Wt1 expression in epiblast, primitive streak, emerging mesoderm and, from E7.5 onwards, in the LPM. Co-expression of signature smooth muscle markers in Wt1-expressing cells in gastrulation-stage embryos revealed that vSMC and visSMC fate is specified independently from visceral mesothelium formation. Furthermore, Tamoxifen-induced Wt1 knock-out at E7.5 affected vascularisation in the E12.5 intestine. Taken together, our study provides novel insight into the developmental lineage of smooth muscle specified by WT1 expression during gastrulation. Summary StatementThis study provides novel insight into the developmental lineage of smooth muscle cells in the intestine and mesentery, specified by WT1 expression during gastrulation.

developmental biology↗

bioRxiv2023

Mesothelial cells exhibit characteristics of perivascular cells in an in vitro angiogenesis assay

Mesothelial cells have been shown to have remarkable plasticity towards mesenchymal cell types during development and in disease situations. Here, we have characterized the potential of mesothelial cells to undergo changes towards perivascular cells using an in vitro angiogenesis assay. We demonstrate that GFP-labelled mesothelial cells (GFP-MCs) aligned closely and specifically with endothelial networks formed when human dermal microvascular endothelial cells (HDMECs) were cultured in the presence of VEGF-A165 on normal human dermal fibroblasts (NHDFs) for a 7-day period. The co-culture with GFP-MCs had a positive effect on branch point formation indicating that the cells supported endothelial tube formation. We interrogated the molecular response of the GFP- MCs to the angiogenic co-culture by qRT-PCR and found that the pericyte marker Ng2 was upregulated when the cells were co-cultured with HDMECs on NHDFs, indicating a change towards a perivascular phenotype. When GFP-MCs were cultured on the NHDF feeder layer, they upregulated the epithelial-mesenchymal transition marker Zeb1 and lost their circularity while increasing their size, indicating a change to a more migratory cell type. We analysed the pericyte- like behavior of the GFP-MCs in a 3D cardiac microtissue (spheroid) with cardiomyocytes, cardiac fibroblasts and cardiac endothelial cells where the mesothelial cells showed alignment with the endothelial cells. These results indicate that mesothelial cells have the potential to adopt a perivascular phenotype and associate with endothelial cells to potentially support angiogenesis.

cell biology↗

bioRxiv2023

Near infrared conjugated polymer nanoparticles (CPN) for tracking cells using fluorescence and optoacoustic imaging

Tracking the biodistribution of cell therapies is crucial for understanding their safety and efficacy. Optical imaging techniques are particularly useful for tracking cells due to their clinical translatability and potential for intra-operative use to validate cell delivery. However, there is a lack of appropriate optical probes for cell tracking. The only FDA-approved material for clinical use is indocyanine green (ICG). ICG can be used for both fluorescence and photoacoustic imaging, but is prone to photodegradation, and at higher concentrations, undergoes quenching and can adversely affect cell health. We have developed novel near-infrared imaging probes comprising conjugated polymer nanoparticles (CPNs) that can be fine-tuned to absorb and emit light at specific wavelengths. To compare the performance of the CPNs with ICG for in vivo cell tracking, labelled mesenchymal stromal cells (MSCs) were injected subcutaneously in mice and detected using fluorescence imaging (FI) and a form of photoacoustic imaging called multispectral optoacoustic tomography (MSOT). MSCs labelled with either ICG or CPN 770 could be detected with FI, but only CPN 770-labelled MSCs could be detected with MSOT. These results show that CPNs show great promise for tracking cells in vivo using optical imaging techniques, and for some applications, out-perform ICG.

bioengineering↗

bioRxiv2022

Intravenous administration of human umbilical cord mesenchymal stromal cells leads to an inflammatory response in the lung

Mesenchymal stromal cells (MSCs) administered intravenously (IV) have shown efficacy in pre-clinical models of various diseases. This is despite the cells not reaching the site of injury due to entrapment in the lungs. The ability of MSCs to modulate immune responses has been proposed as one of the mechanisms by which these cells provide therapeutic benefits, irrespective of whether they are sourced from bone marrow, adipose tissue or umbilical cord. To better understand how MSCs affect innate immune cell populations in the lung, we evaluated the percentage, distribution and phenotype of neutrophils, monocytes and macrophages by flow cytometry and histological analyses after delivering human umbilical cord-derived MSCs (hUC-MSCs) IV into immunocompetent mice. After 2 h, we observed a sharp increase in neutrophils, and pro-inflammatory monocytes and macrophages. Moreover, these immune cells localised in the vicinity of the MSCs suggesting an active role in their clearance. By 24 h, we detected an increase in anti-inflammatory monocytes and macrophages. These results suggest that the IV injection of hUC-MSCs leads to an initial inflammatory phase in the lung shortly after injection, followed by a resolution phase 24 h later.

cell biology↗

bioRxiv2022

Multicentre comparison of biological and functional properties of mesenchymal stromal cells from different sources cultivated using a harmonised manufacturing workflow

BackgroundMesenchymal stromal cells (MSCs), commonly sourced from adipose tissue, bone marrow and umbilical cord, have been widely used in many medical conditions due to their therapeutic potential. Yet, the still limited understanding of the underlying mechanisms of action hampers clinical translation. Clinical potency can vary considerably depending on tissue source, donor attributes, but importantly, also culture conditions. Lack of standard procedures hinders inter-study comparability and delays the progression of the field. The aim of this study was A-to assess the impact on MSC characteristics when different laboratories performed analysis on the same MSC material using harmonised culture conditions and B-to understand source-specific differences. MethodsThree independent institutions performed a head-to-head comparison of human-derived adipose (A-), bone marrow (BM-), and umbilical cord (UC-) MSCs using harmonised culture conditions. In each centre, cells from one specific tissue source were isolated and later distributed across the network to assess their biological properties, including cell expansion, immune phenotype, and tri-lineage differentiation (part A). To assess tissue specific function, angiogenic and immunomodulatory properties and the in vivo biodistribution were compared in one expert lab (part B). ResultsBy implementing a harmonised manufacturing workflow, we obtained largely reproducible results across three independent laboratories in part A of our study. Unique growth patterns and differentiation potential were observed for each tissue source, with similar trends observed between centres. Immune phenotyping verified expression of typical MSC surface markers and absence of contaminating surface markers. Depending on the established protocols in the different laboratories, quantitative data varied slightly. Functional experiments in part B concluded that conditioned media from BM-MSCs significantly enhanced tubulogenesis and endothelial migration in vitro. In contrast, immunomodulatory studies reported superior immunosuppressive abilities for A-MSCs. Biodistribution studies in healthy mice showed lung entrapment after administration of all three types of MSCs, with a significantly faster clearance of BM-MSCs. ConclusionThese results show the heterogeneous behaviour and regenerative properties of MSCs as a reflection of intrinsic tissue-origin properties while providing evidence that the use of standardised culture procedures can reduce but not eliminate inter-lab and operator differences. HighlightsIn this study, we have: - Provided a harmonised manufacturing workflow that has demonstrated reproducible results across three independent laboratories when expanding MSCs. - Defined a multi-assay matrix capable of identifying functional differences in terms of angiogenesis, wound healing abilities and immunosuppressive properties. - Demonstrated similar in vivo biodistribution properties regardless of cell origin.

cell biology↗

bioRxiv2022

Comparison between optical tissue clearing methods for detecting administered mesenchymal stromal cells in mouse lungs

Optical tissue clearing of lung tissue enables the intact lung to be imaged using fluorescence microscopy. Several clearing protocols have been developed in recent years, including the Clear, Unobstructed Brain/Body Imaging Cocktails and Computational analysis (CUBIC), stabilised 3D imaging of solvent-cleared organs (s-DISCO) and Ethyl cinnamate (ECi) methods. Here we compared these protocols with the aim of determining the biodistribution of mesenchymal stroma cells (MSCs) and understanding how they interact with host cells in the mouse lung. First, we evaluated how each method affected the size, morphology, and transparency of the lungs. Then, we compared the preservation of the fluorescence of the protein tdTomato expressed by the MSCs, and of the organic dye Evans Blue which labels the vasculature. In addition, we tested the compatibility of the methods with immunofluorescence staining. We found that CUBIC clearing is the only method that enables direct imaging of fluorescently labelled MSCs in the lungs thereby allowing the study of the MSC interaction with endothelial and immune cells when combined with immunofluorescence staining. Overall, 3D imaging of CUBIC cleared lungs confirmed that injected MSCs are initially retained in the pulmonary microvasculature, and that most cells are eliminated from the lungs within the first 24 h. Summary statementWe present a tissue clearing approach to visualize exogenous MSCs in the mouse lung and study their effects in the host.

physiology↗

bioRxiv2022

Computed tomography lacks sensitivity to image gold labelled mesenchymal stromal cells in vivo as evidenced by multispectral optoacoustic tomography.

Elucidating the mechanisms of action and long-term safety of cell therapies is necessary for their clinical translation. Non-invasive imaging technologies such as bioluminescence imaging (BLI), computed tomography (CT) and multispectral optoacoustic tomography (MSOT) have been proposed as tools for longitudinal cell monitoring but their performances have not been compared. Here, we evaluate combinations of these modalities to track the in vivo distribution of gold-labelled mesenchymal stromal cells (MSCs). We found that injected MSCs labelled with gold nanoparticles and expressing the reporter gene firefly luciferase could be detected with BLI and MSOT but not CT. We conclude that the MSCs did not carry enough contrast agent to be tracked by CT, demonstrating that CT tracking of gold-labelled cells is not a practical approach as high amounts of gold, which might impair cell viability, are necessary.

cell biology↗

bioRxiv2020

Wt1-expressing cells contribute to mesoderm-derived tissues in intestine and mesentery in two distinct phases during murine embryonic development.

Previously, genetic lineage tracing based on the mesothelial marker Wt1, appeared to show that peritoneal mesothelial cells have a range of differentiative capacities and are the direct progenitors of vascular smooth muscle in the intestine. However, it was not clear whether this was a temporally limited process or continued throughout postnatal life. Here, using a conditional Wt1-based genetic lineage tracing approach, we demonstrate that the postnatal and adult peritoneum covering intestine, mesentery and body wall only maintained itself and failed to contribute to other visceral tissues. Pulse-chase experiments of up to 6 months revealed that Wt1-expressing cells remained confined to the peritoneum and failed to differentiate into cellular components of blood vessels or other tissues underlying the peritoneum. Ablation of Wt1 in adult mice did not result in changes to the intestinal wall architecture. In the heart, we observed that Wt1-expressing cells maintained the epicardium and contributed to coronary vessels in newborn and adult mice. Our results demonstrate that Wt1-expressing cells in the peritoneum have limited differentiation capacities, and that contribution of Wt1-expressing cells to cardiac vasculature is based on organ-specific mechanisms.

developmental biology↗

bioRxiv2019

Murine models of renal ischaemia reperfusion injury: An opportunity for refinement using non-invasive monitoring methods

BackgroundRenal Ischaemia Reperfusion Injury (R-IRI) can cause Acute Kidney Injury (AKI) and Chronic Kidney Disease (CKD), resulting in significant morbidity and mortality. To understand the underlying mechanisms, reproducible small-animal models of AKI and CKD are needed. We describe how innovative technologies for measuring kidney function non-invasively in small rodents allow successful refinement of the R-IRI models, and offer the unique opportunity to monitor longitudinally in individual animals the transition from AKI to CKD. MethodsMale BALB/c mice underwent bilateral renal pedicle clamping (AKI) or unilateral renal pedicle clamping with delayed contralateral nephrectomy (CKD) under isoflurane anaesthetic. Transdermal GFR monitoring and multi-spectral optoacoustic tomography in combination with statistical analysis were used to identify and standardise variables within these models. ResultsPre-clamping anaesthetic time was one of the most important predictors of AKI severity after R-IRI. Standardising pre-clamping time resulted in a more predictably severe AKI model. In the CKD model, initial improvement in renal function was followed by significant progressive reduction in function between weeks 2 and 4. Performing contralateral nephrectomy on day 14 enabled the development of CKD in a survivable way. ConclusionsNon-invasive monitoring of global and individual renal function after R-IRI is feasible, reproducible and correlates well with classical markers of injury. This facilitates refinement of kidney injury models and enables the degree of injury seen in pre-clinical models to be translated to those seen in the clinical setting. Thus, future therapies can be tested in a clinically relevant, non-invasive manner. What is already knownThe severity of Renal Ischaemia Reperfusion injury (R-IRI) varies between animal strain, gender and age. Experimental variables including temperature and clamping time are usually tightly controlled but significant variability still exists. Classically, small rodent experiments depend on endpoint evaluation of serum and histological features of disease. However, new technologies including transdermal glomerular filtration rate (GFR) monitoring and Multispectral Optoacoustic Tomography (MSOT) may enable renal function to be accurately monitored longitudinally, enabling better refinement of these models. What this study addsThis study shows that transdermal GFR measurements have reliably enabled refinement of the R-IRI model by standardisation of the duration of isoflurane prior to commencing surgery. Individual kidney function can be assessed in-vivo after unilateral R-IRI using MSOT imaging. The excretion tmax of IRDye-800 reliably represents the relative function of the injured kidney, permitting longitudinal in-vivo assessment of differential kidney function. What impact this may have on practiceThis study demonstrates the utility of two minimally-invasive in-vivo methods of monitoring kidney function which have advantages over classical methods and potentially enable fewer animals to be used in future studies. The study demonstrates refinement of bilateral and unilateral R-IRI models which will also enable a reduction in the number of animals needed for experimentation.

physiology↗

bioRxiv2018

In vivo fate of free and encapsulated iron oxide nanoparticles after injection of labelled stem cells

Nanoparticle contrast agents are useful tools to label stem cells and monitor the in vivo bio-distribution of labeled cells in pre-clinical models of disease. In this context, understanding the in vivo fate of the particles after injection of labelled cells is important for their eventual clinical use as well as for the interpretation of imaging results. We examined how the formulation of superparamagnetic iron oxide nanoparticles (SPIONs) impacts the labelling efficiency, magnetic characteristics and fate of the particles by comparing individual SPIONs with polyelectrolyte multilayer capsules containing SPIONs. At low labelling concentration, encapsulated SPIONs served as an efficient labelling agent for stem cells. The bio-distribution after intra-cardiac injection of labelled cells was monitored longitudinally by MRI and as an endpoint by inductively coupled plasma-optical emission spectrometry. The results suggest that, after being released from labelled cells after cell death, both formulations of particles are initially stored in liver and spleen and are not completely cleared from these organs 2 weeks post-injection.

biochemistry↗

bioRxiv2018

Development of an imaging toolbox to assess the therapeutic potential and biodistribution of macrophages in a mouse model of multiple organ dysfunction

Cell-based regenerative medicine therapies require robust preclinical safety, efficacy, biodistribution and engraftment data prior to clinical testing. To address these challenges, we have developed an imaging toolbox comprising multi-spectral optoacoustic tomography and ultrasonography, which allows the degree of kidney, liver and cardiac injury and the extent of functional recovery to be assessed non-invasively in a mouse model of multi-organ dysfunction. This toolbox allowed us to determine the therapeutic effects of adoptively transferred M2 macrophages. Using bioluminescence imaging, we could then investigate the association between amelioration and biodistribution. Macrophage therapy improved kidney and liver function to a limited extent, but did not ameliorate histological damage. No improvement in cardiac function was observed. Biodistribution analysis showed that macrophages homed and persisted in the injured kidneys and liver, but did not populate the heart. Our data suggest that the limited improvement observed in kidney and liver function could be mediated by M2 macrophages.

pharmacology and toxicology↗

bioRxiv2017

Ex vivo live cell tracking in kidney organoids using light sheet fluorescence microscopy

Screening cells for their differentiation potential requires a combination of tissue culture models and imaging methods that allow for long-term tracking of the location and function of cells. Embryonic kidney re-aggregation in vitro assays have been established which allow for the monitoring of organotypic cell behaviour in re-aggregated and chimeric renal organoids. However, evaluation of cell integration is hampered by the high photonic load of standard fluorescence microscopy which poses challenges for imaging three-dimensional systems in real-time over a time course. Therefore, we employed light sheet microscopy, a technique that vastly reduces photobleaching and phototoxic effects. We have also developed a new method for culturing the re-aggregates which involves immersed culture, generating organoids which more closely reflect development in vivo. To facilitate imaging from various angles, we embedded the organoids in a freely rotatable hydrogel cylinder. Endpoint fixing and staining were performed to provide additional biomolecular information. We succeeded in imaging labelled cells within re-aggregated kidney organoids over 15 hours and tracking their fate while simultaneously monitoring the development of organotypic morphological structures. Our results show that Wt1-expressing embryonic kidney cells obtained from transgenic mice could integrate into re-aggregated chimeric kidney organoids and contribute to developing nephrons. Furthermore, the nascent proximal tubules that formed in the re-aggregated tissues using the new culture method displayed secretory function, as evidenced by their ability to secrete an organic anion mimic into the tubular lumen.

developmental biology↗

bioRxiv2017

Non-invasive imaging platform reveals a potential tumourigenicity hazard of systemically administered cells

BackgroundCell-based regenerative medicine therapies are now frequently tested in clinical trials. In many conditions, cell therapies are administered systemically, but there is little understanding of their fate, and adverse events are often under-reported. Currently, it is only possible to assess safety and fate of cell therapies in preclinical studies, specifically by monitoring animals longitudinally using multimodal imaging approaches. Here, using a suite of in vivo imaging modalities to explore the fate of a range of human and murine cells, we investigate how route of administration, cell type and host immune status affect the fate of administered cells.\n\nMethodsWe applied a unique imaging toolkit combining bioluminescence, optoacoustic and magnetic resonance imaging modalities to assess the safety of different human and murine cell types by following their biodistribution and persistence in mice following administration into the venous or arterial system. Results: Longitudinal imaging analyses (i) suggested that the intra-arterial route may be more hazardous than intravenous administration for certain cell types; (ii) revealed that the potential of a mouse mesenchymal stem/stromal cell (MSC) line to form tumours, depended on administration route and mouse strain; and (iii) indicated that clinically tested human umbilical cord (hUC)-derived MSCs can transiently and unexpectedly proliferate when administered intravenously to mice.\n\nConclusionsIn order to perform an adequate safety assessment of potential cell-based therapies, a thorough understanding of cell biodistribution and fate post administration is required. The non-invasive imaging toolbox used here can expose not only the general organ distribution of these therapies, but also a detailed view of their presence within different organs and, importantly, tumourigenic potential. Our observation that the hUC-MSCs but not the human bone marrow (hBM)-derived MSCs persisted for a period in some animals, suggests that therapies with these cells should proceed with caution.

cell biology↗

bioRxiv2017

Multimodal cell tracking from systemic administration to tumour growth by combining gold nanorods and reporter genes

Understanding the fate of exogenous cells after implantation is important for clinical applications. Preclinical studies allow imaging of cell location and survival. Labelling with nanoparticles enables high sensitivity detection, but cell division and cell death cause signal dilution and false positives. By contrast, genetic reporter signals are amplified by cell division. Here we characterise lentivirus-based bi-cistronic reporter gene vectors and silica-coated gold nanorods (GNRs) as synergistic tools for cell labelling and tracking. Co-expression of the bioluminescence reporter luciferase and the optoacoustic reporter near-infrared fluorescent protein iRFP720 enabled cell tracking over time in mice. Multispectral optoacoustic tomography (MSOT) showed immediate biodistribution of GNR-labelled cells after intracardiac injection and successive clearance of GNRs (day 1-15) with high resolution, while optoacoustic iRFP720 detection indicated tumour growth (day 10-40). This multimodal cell tracking approach could be applied widely for cancer and regenerative medicine research to monitor short- and long-term biodistribution, tumour formation and metastasis.

cell biology↗