Assessing the toxicity of one-step-synthesized PEG-coated gold nanoparticles: in vitro and in vivo studies.

OBJECTIVE: To evaluate the in vitro and in vivo toxicities of polyethylene glycol-coated gold nanoparticles synthesized using a one-step process. METHODS: Gold nanoparticles were prepared via a co-precipitation method using polyethylene glycol, and the synthesis product was characterized. For the in vitro evaluation, a flow cytometry analysis with Annexin V and iodide propidium staining was used to assess cytotoxicity in MG-63 cells labeled with 10, 50, and 100µg/mL of nanoparticle concentration. For the in vivo evaluation, nanoparticles were administered intraperitoneally at a dose of 10mg/kg dose in 10-week-old mice. Toxicity was assessed 24 hours and 7 days after administration via histopathological analysis of various tissues, as well as through renal, hepatic, and hematopoietic evaluations. RESULTS: Synthesized nanoparticles exhibited different hydrodynamic sizes depending on the medium: 51.27±1.62nm in water and 268.12±28.45nm (0 hour) in culture medium. They demonstrated a maximum absorbance at 520nm and a zeta potential of -8.419mV. Cellular viability exceeded 90%, with less than 3% early apoptosis, 6% late apoptosis, and 1% necrosis across all labeling conditions, indicating minimal cytotoxicity differences. Histopathological analysis highlighted the accumulation of nanoparticles in the mesentery; however, no lesions or visible agglomeration was observed in the remaining tissues. Renal, hepatic, and hematopoietic analyses showed no significant differences at any time point. CONCLUSION: Polyethylene glycol-coated gold nanoparticles exhibit extremely low toxicity and high biocompatibility, showing promise for future studies.

Development of Ac2-26 Mesoporous Microparticle System as a Potential Therapeutic Agent for Inflammatory Bowel Diseases.

Introduction: Inflammatory bowel diseases (IBDs) disrupt the intestinal epithelium, leading to severe chronic inflammation. Current therapies cause adverse effects and are expensive, invasive, and ineffective for most patients. Annexin A1 (AnxA1) is a pivotal endogenous anti-inflammatory and tissue repair protein in IBD. Nanostructured compounds loading AnxA1 or its active N-terminal mimetic peptides improve IBD symptomatology. Methods: To further explore their potential as a therapeutic candidate, the AnxA1 N-terminal mimetic peptide Ac2-26 was incorporated into SBA-15 ordered mesoporous silica and covered with EL30D-55 to deliver it by oral treatment into the inflamed gut. Results: The systems SBA-Ac2-26 developed measurements revealed self-assembled rod-shaped particles, likely on the external surface of SBA-15, and 88% of peptide incorporation. SBA-15 carried the peptide Ac2-26 into cultured Raw 264.7 macrophages and Caco-2 epithelial cells. Moreover, oral administration of Eudragit-SBA-15-Ac2-26 (200 µg; once a day; for 4 days) reduced colitis clinical symptoms, inflammation, and improved epithelium recovery in mice under dextran-sodium sulfate-induced colitis. Discussion: The absorption of SBA-15 in gut epithelial cells is typically low; however, the permeable inflamed barrier can enable microparticles to cross, being phagocyted by macrophages. These findings suggest that Ac2-26 is successfully delivered and binds to its receptors in both epithelial and immune cells, aligning with the clinical results. Conclusion: Our findings demonstrate a simple and cost-effective approach to delivering Ac2-26 orally into the inflamed gut, highlighting its potential as non-invasive IBD therapy.

Breast Cancer Treatment Using the Magneto-Hyperthermia Technique Associated with Omega-3 Polyunsaturated Fatty Acids' Supplementation and Physical Training.

Breast cancer (BC) presents a growing global concern, mainly for the female population of working age. Their pathophysiology shows challenges when attempting to ensure conventional treatment efficacy without adverse effects. This study aimed to evaluate the efficacy of magneto-hyperthermia (MHT) therapy associated with supplementation with omega-3 polyunsaturated fatty acid (w-3 PUFA) and engagement in physical training (PT) for the triple-negative BC (TNBC) model. First, we assessed the physicochemical properties of iron oxide nanoparticles (ION) in biological conditions, as well as their heating potential for MHT therapy. Then, a bioluminescence (BLI) evaluation of the best tumor growth conditions in the TNBC model (the quantity of implanted cells and time), as well as the efficacy of MHT therapy (5 consecutive days) associated with the previous administration of 8 weeks of w-3 PUFA and PT, was carried out. The results showed the good stability and potential of ION for MHT using 300 Gauss and 420 kHz. In the TNBC model, adequate tumor growth was observed after 14 days of 2 × 106 cells implantation by BLI. There was a delay in tumor growth in animals that received w-3 and PT and a significant decrease associated with MHT. This pioneering combination therapy approach (MHT, omega-3, and exercise) showed a positive effect on TNBC tumor reduction and demonstrated promise for pre-clinical and clinical studies in the future.

Assessing the toxicity of one-step-synthesized PEG-coated gold nanoparticles: in vitro and in vivo studies

ABSTRACT Objective To evaluate the in vitro and in vivo toxicities of polyethylene glycol-coated gold nanoparticles synthesized using a one-step process. Methods Gold nanoparticles were prepared via a co-precipitation method using polyethylene glycol, and the synthesis product was characterized. For the in vitro evaluation, a flow cytometry analysis with Annexin V and iodide propidium staining was used to assess cytotoxicity in MG-63 cells labeled with 10, 50, and 100µg/mL of nanoparticle concentration. For the in vivo evaluation, nanoparticles were administered intraperitoneally at a dose of 10mg/kg dose in 10-week-old mice. Toxicity was assessed 24 hours and 7 days after administration via histopathological analysis of various tissues, as well as through renal, hepatic, and hematopoietic evaluations. Results Synthesized nanoparticles exhibited different hydrodynamic sizes depending on the medium: 51.27±1.62nm in water and 268.12±28.45nm (0 hour) in culture medium. They demonstrated a maximum absorbance at 520nm and a zeta potential of -8.419mV. Cellular viability exceeded 90%, with less than 3% early apoptosis, 6% late apoptosis, and 1% necrosis across all labeling conditions, indicating minimal cytotoxicity differences. Histopathological analysis highlighted the accumulation of nanoparticles in the mesentery; however, no lesions or visible agglomeration was observed in the remaining tissues. Renal, hepatic, and hematopoietic analyses showed no significant differences at any time point. Conclusion Polyethylene glycol-coated gold nanoparticles exhibit extremely low toxicity and high biocompatibility, showing promise for future studies.

Current overview of induced pluripotent stem cell-based blood-brain barrier-on-a-chip.

BACKGROUND: Induced pluripotent stem cells (iPSCs) show great ability to differentiate into any tissue, making them attractive candidates for pathophysiological investigations. The rise of organ-on-a-chip technology in the past century has introduced a novel way to make in vitro cell cultures that more closely resemble their in vivo environments, both structural and functionally. The literature still lacks consensus on the best conditions to mimic the blood-brain barrier (BBB) for drug screening and other personalized therapies. The development of models based on BBB-on-a-chip using iPSCs is promising and is a potential alternative to the use of animals in research. AIM: To analyze the literature for BBB models on-a-chip involving iPSCs, describe the microdevices, the BBB in vitro construction, and applications. METHODS: We searched for original articles indexed in PubMed and Scopus that used iPSCs to mimic the BBB and its microenvironment in microfluidic devices. Thirty articles were identified, wherein only 14 articles were finally selected according to the inclusion and exclusion criteria. Data compiled from the selected articles were organized into four topics: (1) Microfluidic devices design and fabrication; (2) characteristics of the iPSCs used in the BBB model and their differentiation conditions; (3) BBB-on-a-chip reconstruction process; and (4) applications of BBB microfluidic three-dimensional models using iPSCs. RESULTS: This study showed that BBB models with iPSCs in microdevices are quite novel in scientific research. Important technological advances in this area regarding the use of commercial BBB-on-a-chip were identified in the most recent articles by different research groups. Conventional polydimethylsiloxane was the most used material to fabricate in-house chips (57%), whereas few studies (14.3%) adopted polymethylmethacrylate. Half the models were constructed using a porous membrane made of diverse materials to separate the channels. iPSC sources were divergent among the studies, but the main line used was IMR90-C4 from human fetal lung fibroblast (41.2%). The cells were differentiated through diverse and complex processes either to endothelial or neural cells, wherein only one study promoted differentiation inside the chip. The construction process of the BBB-on-a-chip involved previous coating mostly with fibronectin/collagen IV (39.3%), followed by cell seeding in single cultures (36%) or co-cultures (64%) under controlled conditions, aimed at developing an in vitro BBB that mimics the human BBB for future applications. CONCLUSION: This review evidenced technological advances in the construction of BBB models using iPSCs. Nonetheless, a definitive BBB-on-a-chip has not yet been achieved, hindering the applicability of the models.

How mesenchymal stem cell cotransplantation with hematopoietic stem cells can improve engraftment in animal models.

BACKGROUND: Bone marrow transplantation (BMT) can be applied to both hematopoietic and nonhematopoietic diseases; nonetheless, it still comes with a number of challenges and limitations that contribute to treatment failure. Bearing this in mind, a possible way to increase the success rate of BMT would be cotransplantation of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) to improve the bone marrow niche and secrete molecules that enhance the hematopoietic engraftment. AIM: To analyze HSC and MSC characteristics and their interactions through cotransplantation in murine models. METHODS: We searched for original articles indexed in PubMed and Scopus during the last decade that used HSC and MSC cotransplantation and in vivo BMT in animal models while evaluating cell engraftment. We excluded in vitro studies or studies that involved graft versus host disease or other hematological diseases and publications in languages other than English. In PubMed, we initially identified 555 articles and after selection, only 12 were chosen. In Scopus, 2010 were identified, and six were left after the screening and eligibility process. RESULTS: Of the 2565 articles found in the databases, only 18 original studies met the eligibility criteria. HSC distribution by source showed similar ratios, with human umbilical cord blood or animal bone marrow being administered mainly with a dose of 1 × 107 cells by intravenous or intrabone routes. However, MSCs had a high prevalence of human donors with a variety of sources (umbilical cord blood, bone marrow, tonsil, adipose tissue or fetal lung), using a lower dose, mainly 106 cells and ranging 104 to 1.5 × 107 cells, utilizing the same routes. MSCs were characterized prior to administration in almost every experiment. The recipient used was mostly immunodeficient mice submitted to low-dose irradiation or chemotherapy. The main technique of engraftment for HSC and MSC cotransplantation evaluation was chimerism, followed by hematopoietic reconstitution and survival analysis. Besides the engraftment, homing and cellularity were also evaluated in some studies. CONCLUSION: The preclinical findings validate the potential of MSCs to enable HSC engraftment in vivo in both xenogeneic and allogeneic hematopoietic cell transplantation animal models, in the absence of toxicity.

Convalescent plasma therapy in COVID-19 critically ill patients during advanced phases of clinical trials and their preliminary results.

The objective of this study was to highlight the global scientific effort to fight the SARS-CoV-2, addressing the preliminary results of passive immunization through convalescent plasma. We performed a search at the major databases of interventional clinical trial protocols about the transfusion of convalescent plasma in patients with COVID-19, as well as, published articles (n≥25), using the following search strategy: [(COVID-19 OR SARS-CoV-2 OR nCoV-2019) AND (Convalescent plasma OR Plasma exchange) AND (Treatment OR Therapy)]. A total of 24 interventional clinical trial protocols (advanced in phases II-III, III, and IV) were included in this review, as well as three studies that had enough outcomes to evaluate the efficacy of convalescent plasma therapy for patients with COVID-19. All interventional clinical trial protocols applied approximately 500mL of convalescent plasma (from single or more donations) in hospitalized patients, mainly in patients with severe disease associated with standard therapy for COVID-19, and compared to placebo or standard therapy plus specific drugs. Most of interventional clinical trial protocols are multicenter, and the phase IV studies are recruiting at intercontinental centers of North America, Oceania, Europe, but most are recruiting center inside their own county. The three studies published reported similar approach of convalescent plasma intervention with decrease in length of stay, mortality, with less than 4% of adverse events, mainly for treating critical cases with life-threatening disease. All advanced clinical trials focused on convalescent plasma therapy in patients with COVID-19 hospitalized in severe conditions, and the preliminary results provide strong evidence for therapy for the COVID-19 patients.

Convalescent plasma therapy in COVID-19 critically ill patients during advanced phases of clinical trials and their preliminary results / Terapia com plasma convalescente em pacientes graves com COVID-19 nas fases avançadas dos ensaios clínicos e seus resultados preliminares

ABSTRACT The objective of this study was to highlight the global scientific effort to fight the SARS-CoV-2, addressing the preliminary results of passive immunization through convalescent plasma. We performed a search at the major databases of interventional clinical trial protocols about the transfusion of convalescent plasma in patients with COVID-19, as well as, published articles (n≥25), using the following search strategy: [(COVID-19 OR SARS-CoV-2 OR nCoV-2019) AND (Convalescent plasma OR Plasma exchange) AND (Treatment OR Therapy)]. A total of 24 interventional clinical trial protocols (advanced in phases II-III, III, and IV) were included in this review, as well as three studies that had enough outcomes to evaluate the efficacy of convalescent plasma therapy for patients with COVID-19. All interventional clinical trial protocols applied approximately 500mL of convalescent plasma (from single or more donations) in hospitalized patients, mainly in patients with severe disease associated with standard therapy for COVID-19, and compared to placebo or standard therapy plus specific drugs. Most of interventional clinical trial protocols are multicenter, and the phase IV studies are recruiting at intercontinental centers of North America, Oceania, Europe, but most are recruiting center inside their own county. The three studies published reported similar approach of convalescent plasma intervention with decrease in length of stay, mortality, with less than 4% of adverse events, mainly for treating critical cases with life-threatening disease. All advanced clinical trials focused on convalescent plasma therapy in patients with COVID-19 hospitalized in severe conditions, and the preliminary results provide strong evidence for therapy for the COVID-19 patients.

RESUMO O objetivo deste estudo foi destacar o esforço científico global para combater o SARS-CoV-2 abordando os resultados preliminares da imunização passiva por plasma convalescente. Foi realizada uma busca nas principais bases de dados dos protocolos de ensaios clínicos intervencionistas sobre transfusão de plasma convalescente em pacientes com COVID-19, bem como artigos publicados (n≥25), utilizando a seguinte estratégia de busca: [(COVID-19 OR SARS-CoV-2 OR nCoV-2019) AND (Convalescent plasma OR Plasma exchange) AND (Treatment OR Therapy)]. Um total de 24 protocolos de ensaios clínicos intervencionistas (avançados nas fases II-III, III e IV) foi incluído nesta revisão, assim como três estudos que tiveram resultados suficientes para avaliar a eficácia da terapia com plasma convalescente para pacientes com COVID-19. Todos os protocolos de ensaios clínicos intervencionistas aplicaram cerca de 500mL de plasma convalescente (de uma ou mais doações) em pacientes hospitalizados, principalmente naqueles com grau grave de doença associada à terapia-padrão para COVID-19 em comparação com placebo ou terapia-padrão mais medicamentos específicos. A maioria dos protocolos de ensaios clínicos intervencionistas é multicêntrica, e os estudos de fase IV estão recrutando em centros intercontinentais da América do Norte, Oceania e Europa, mas a maior parte dos centros de recrutamento está dentro de seu próprio país. Os três estudos publicados relataram abordagem semelhante de intervenção para plasma convalescente com redução do tempo de internação, mortalidade e menos de 4% de eventos adversos, principalmente para o tratamento de casos críticos com risco de vida. Todos os ensaios clínicos avançados focaram na terapia com plasma convalescente em pacientes com COVID-19 hospitalizados em condições graves, e os resultados preliminares fornecem fortes evidências para a terapia para esses pacientes com COVID-19.

Stem cell homing, tracking and therapeutic efficiency evaluation for stroke treatment using nanoparticles: A systematic review.

BACKGROUND: Stroke is the second leading cause of death worldwide. There is a real need to develop treatment strategies for reducing neurological deficits in stroke survivors, and stem cell (SC) therapeutics appear to be a promising alternative for stroke therapy that can be used in combination with approved thrombolytic or thrombectomy approaches. However, the efficacy of SC therapy depends on the SC homing ability and engraftment into the injury site over a long period of time. Nonetheless, tracking SCs from their niche to the target tissues is a complex process. AIM: To evaluate SC migration homing, tracking and therapeutic efficacy in the treatment of stroke using nanoparticles. METHODS: A systematic literature search was performed to identify articles published prior to November 2019 that were indexed in PubMed and Scopus. The following inclusion criteria were used: (1) Studies that used in vivo models of stroke or ischemic brain lesions; (2) Studies of SCs labeled with some type of contrast agent for cell migration detection; and (3) Studies that involved in vivo cellular homing and tracking analysis. RESULTS: A total of 82 articles were identified by indexing in Scopus and PubMed. After the inclusion criteria were applied, 35 studies were selected, and the articles were assessed for eligibility; ultimately, only 25 studies were included. Most of the selected studies used SCs from human and mouse bone marrow labeled with magnetic nanoparticles alone or combined with fluorophore dyes. These cells were administered in the stroke model (to treat middle cerebral artery occlusion in 74% of studies and for photothrombotic induction in 26% of studies). Fifty-three percent of studies used xenogeneic grafts for cell therapy, and the migration homing and tracking evaluation was performed by magnetic resonance imaging as well as other techniques, such as near-infrared fluorescence imaging (12%) or bioluminescence assays (12%). CONCLUSION: Our systematic review provided an up-to-date evaluation of SC migration homing and the efficacy of cellular therapy for stroke treatment in terms of functional and structural improvements in the late stage.

Magnetic hyperthermia therapy in glioblastoma tumor on-a-Chip model.

OBJECTIVE: To evaluate the magnetic hyperthermia therapy in glioblastoma tumor-on-a-Chip model using a microfluidics device. METHODS: The magnetic nanoparticles coated with aminosilane were used for the therapy of magnetic hyperthermia, being evaluated the specific absorption rate of the magnetic nanoparticles at 300 Gauss and 305kHz. A preculture of C6 cells was performed before the 3D cells culture on the chip. The process of magnetic hyperthermia on the Chip was performed after administration of 20µL of magnetic nanoparticles (10mgFe/mL) using the parameters that generated the specific absorption rate value. The efficacy of magnetic hyperthermia therapy was evaluated by using the cell viability test through the following fluorescence staining: calcein acetoxymethyl ester (492/513nm), for live cells, and ethidium homodimer-1 (526/619nm) for dead cells dyes. RESULTS: Magnetic nanoparticles when submitted to the alternating magnetic field (300 Gauss and 305kHz) produced a mean value of the specific absorption rate of 115.4±6.0W/g. The 3D culture of C6 cells evaluated by light field microscopy imaging showed the proliferation and morphology of the cells prior to the application of magnetic hyperthermia therapy. Fluorescence images showed decreased viability of cultured cells in organ-on-a-Chip by 20% and 100% after 10 and 30 minutes of the magnetic hyperthermia therapy application respectively. CONCLUSION: The study showed that the therapeutic process of magnetic hyperthermia in the glioblastoma on-a-chip model was effective to produce the total cell lise after 30 minutes of therapy.

Magnetic hyperthermia therapy in glioblastoma tumor on-a-Chip model / Terapia de magneto-hipertermia no modelo de tumor de glioblastoma on-a-Chip

ABSTRACT Objective: To evaluate the magnetic hyperthermia therapy in glioblastoma tumor-on-a-Chip model using a microfluidics device. Methods: The magnetic nanoparticles coated with aminosilane were used for the therapy of magnetic hyperthermia, being evaluated the specific absorption rate of the magnetic nanoparticles at 300 Gauss and 305kHz. A preculture of C6 cells was performed before the 3D cells culture on the chip. The process of magnetic hyperthermia on the Chip was performed after administration of 20μL of magnetic nanoparticles (10mgFe/mL) using the parameters that generated the specific absorption rate value. The efficacy of magnetic hyperthermia therapy was evaluated by using the cell viability test through the following fluorescence staining: calcein acetoxymethyl ester (492/513nm), for live cells, and ethidium homodimer-1 (526/619nm) for dead cells dyes. Results: Magnetic nanoparticles when submitted to the alternating magnetic field (300 Gauss and 305kHz) produced a mean value of the specific absorption rate of 115.4±6.0W/g. The 3D culture of C6 cells evaluated by light field microscopy imaging showed the proliferation and morphology of the cells prior to the application of magnetic hyperthermia therapy. Fluorescence images showed decreased viability of cultured cells in organ-on-a-Chip by 20% and 100% after 10 and 30 minutes of the magnetic hyperthermia therapy application respectively. Conclusion: The study showed that the therapeutic process of magnetic hyperthermia in the glioblastoma on-a-chip model was effective to produce the total cell lise after 30 minutes of therapy.

RESUMO Objetivo: Avaliar a terapia de magneto-hipertermia em modelo de tumor de glioblastoma on-a-Chip. Métodos: As nanopartículas magnéticas recobertas com aminosilana foram utilizadas para a terapia da magneto-hipertermia, sendo avaliada a taxa de absorção específica das nanopartículas magnéticas em 300 Gauss e 305kHz. Uma pré-cultura de células C6 foi realizada e, seguidamente, foi feito o cultivo das células 3D no chip. O processo de magneto-hipertermia no chip foi realizado após administração de 20μL de nanopartículas magnéticas (10mgFe/mL), utilizando os parâmetros que geraram o valor da taxa de absorção específica. A eficácia da terapia de magneto-hipertermia foi avaliada pela viabilidade celular por meio dos corantes fluorescentes acetoximetiléster de calceína (492/513nm), para células vivas, e etídio homodímero-1 (526/619nm), para células mortas. Resultados: As nanopartículas magnéticas, quando submetidas ao campo magnético alternado (300 Gauss e 305kHz), produziram um valor médio da taxa de absorção específica de 115,4±6,0W/g. A cultura 3D das células C6 avaliada por imagem de microscopia de campo claro mostrou a proliferação e a morfologia das células antes da aplicação da terapia de magneto-hipertermia. As imagens de fluorescência mostraram diminuição da viabilidade das células cultivadas no organ-on-a-Chip em 20% e 100% após 10 e 30 minutos, respectivamente, da aplicação da terapia de magneto-hipertermia. Conclusão: O processo terapêutico da magneto-hipertermia no modelo de tumor glioblastoma on-a-chip foi eficaz para produzir lise total das células após 30 minutos de terapia.

Triple-modal imaging of stem-cells labeled with multimodal nanoparticles, applied in a stroke model.

BACKGROUND: Mesenchymal stem cells (MSCs) have been widely tested for their therapeutic efficacy in the ischemic brain and have been shown to provide several benefits. A major obstacle to the clinical translation of these therapies has been the inability to noninvasively monitor the best route, cell doses, and collateral effects while ensuring the survival and effective biological functioning of the transplanted stem cells. Technological advances in multimodal imaging have allowed in vivo monitoring of the biodistribution and viability of transplanted stem cells due to a combination of imaging technologies associated with multimodal nanoparticles (MNPs) using new labels and covers to achieve low toxicity and longtime residence in cells. AIM: To evaluate the sensitivity of triple-modal imaging of stem cells labeled with MNPs and applied in a stroke model. METHODS: After the isolation and immunophenotypic characterization of human bone marrow MSCs (hBM-MSCs), our team carried out lentiviral transduction of these cells for the evaluation of bioluminescent images (BLIs) in vitro and in vivo. In addition, MNPs that were previously characterized (regarding hydrodynamic size, zeta potential, and optical properties), and were used to label these cells, analyze cell viability via the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay and BLI analysis, and quantify the internalization process and iron load in different concentrations of MNPs via magnetic resonance imaging (MRI), near-infrared fluorescence (NIRF), and inductively coupled plasma-mass spectrometry (ICP-MS). In in vivo analyses, the same labeled cells were implanted in a sham group and a stroke group at different times and under different MNP concentrations (after 4 h or 6 d of cell implantation) to evaluate the sensitivity of triple-modal images. RESULTS: hBM-MSC collection and isolation after immunophenotypic characterization were demonstrated to be adequate in hBM samples. After transduction of these cells with luciferase (hBM-MSCLuc), we detected a maximum BLI intensity of 2.0 x 108 photons/s in samples of 106 hBM-MSCs. Analysis of the physicochemical characteristics of the MNPs showed an average hydrodynamic diameter of 38.2 ± 0.5 nm, zeta potential of 29.2 ± 1.9 mV and adequate colloidal stability without agglomeration over 18 h. The signal of iron load internalization in hBM-MSCLuc showed a close relationship with the corresponding MNP-labeling concentrations based on MRI, ICP-MS and NIRF. Under the highest MNP concentration, cellular viability showed a reduction of less than 10% compared to the control. Correlation analysis of the MNP load internalized into hBM-MSCLuc determined via the MRI, ICP-MS and NIRF techniques showed the same correlation coefficient of 0.99. Evaluation of the BLI, NIRF, and MRI signals in vivo and ex vivo after labeled hBM-MSCLuc were implanted into animals showed differences between different MNP concentrations and signals associated with different techniques (MRI and NIRF; 5 and 20 µg Fe/mL; P < 0.05) in the sham groups at 4 h as well as a time effect (4 h and 6 d; P < 0.001) and differences between the sham and stroke groups in all images signals (P < 0.001). CONCLUSION: This study highlighted the importance of quantifying MNPs internalized into cells and the efficacy of signal detection under the triple-image modality in a stroke model.