Publications by authors named "Sukhbaatar Ariunbuyan"

Intravesical instillation of chemotherapy has been performed to reduce the risk of intravesical recurrence of bladder cancer. However, its antitumor effect is not necessarily sufficient, which may be partially due to inadequate delivery of intravesically administered chemotherapeutic agents to bladder tumors. Ultrasound irradiation to target tissues in the presence of microbubbles is a technique to transiently enhance cell membrane permeability and achieve efficient drug delivery to the desired sites without damage to non-target areas; this technique has been used in chemotherapy, immunotherapy, gene therapy, and radiotherapy for the treatment of various cancers.

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Article Synopsis
  • Combining radiotherapy with immunotherapy, particularly using anti-CTLA-4 antibodies, has been shown to enhance survival and response rates against solid tumors compared to using just one treatment.
  • Current intravenous delivery methods for anti-CTLA-4 have limitations in efficacy, especially regarding tumor control and metastasis inhibition.
  • A study demonstrated that using a lymphatic drug delivery system (LDDS) for local administration of anti-CTLA-4 in combination with radiotherapy significantly suppressed tumor growth and metastases, showcasing the potential of LDDS in enhancing the effectiveness of radioimmunotherapy.
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Recently, sentinel lymph nodes (LNs) have been recognized as a starting point of hematogenous metastasis; thus, an increase in the control rate of LN metastasis is expected to improve the survival rate. Although surgical treatment and radiation therapy are commonly used for the radical treatment of LNs, these treatments are associated with lymphedema, pain, and an extended hospital stay. In a recent mouse study, activation of metastatic tumors in distant organs was reported after removing LNs, with or without metastasis to the LNs.

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We aimed to determine potential risk factors for COVID-19 severity including serum vitamin D levels and latent TB infection among Mongolian inpatients diagnosed with COVID-19, and to study the effects of disease complications and treatment outcomes. This study included patients admitted to the Mongolian National Center for Communicable Disease, a main referral center for infectious disease in Mongolia, with COVID-19 ascertained by a positive PCR test. Patients' demographic, clinical, and laboratory data were analyzed.

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Lymph node metastasis (LNM) has a significant impact on cancer prognosis, emphasizing the need for effective treatment strategies. This study investigated the potential use of high osmotic pressure drug solutions with low viscosity administration using a lymphatic drug delivery system (LDDS) to improve LNM treatment outcomes. The hypothesis was that injection of epirubicin or nimustine at high osmotic pressure but without altered viscosity would enhance drug retention and accumulation in LNs, thereby improving the efficacy of treatment.

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Background: Immune checkpoint blockade (ICB) elicits a strong and durable therapeutic response, but its application is limited by disparate responses and its associated immune-related adverse events (irAEs). Previously, in a murine model of lymph node (LN) metastasis, we showed that intranodal administration of chemotherapeutic agents using a lymphatic drug delivery system (LDDS) elicits stronger therapeutic responses in comparison to systemic drug delivery approaches, while minimizing systemic toxicity, due to its improved pharmacokinetic profile at the intended site. Importantly, the LN is a reservoir of immunotherapeutic targets.

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Treatment of metastatic lymph nodes (LNs) is challenging due to their unique architecture and biophysical traits. Systemic chemotherapy fails to impede tumor progression in LNs due to poor drug uptake and retention by LNs, resulting in fatal systemic metastasis. To effectively treat LN metastasis, achieving specific and prolonged retention of chemotherapy drugs in the tumor-draining LNs is essential.

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Chemotherapy using a lymphatic drug delivery system (LDDS) targeting lymph nodes (LNs) in the early stage of metastasis has a superior antitumor effect to systemic chemotherapy. An LDDS produces a higher drug retention rate and tissue selectivity in LNs. To expand the therapeutic coverage of LDDS from local treatment of metastatic LNs to prevention of distant metastases, the combination of treatment with therapies that enhance systemic tumor immune effects is an important therapeutic strategy.

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Bioluminescence (BL) imaging is a powerful non-invasive imaging modality widely used in a broad range of biological disciplines for many types of measurements. The applications of BL imaging in biomedicine are diverse, including tracking bacterial progression, research on gene expression patterns, monitoring tumor cell growth/regression or treatment responses, determining the location and proliferation of stem cells, and so on. It is particularly valuable when studying tissues at depths of 1 to 2 cm in mouse models during preclinical research.

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Delivery of chemotherapeutic agents into metastatic lymph nodes (LNs) is challenging as they are unevenly distributed in the body. They are difficult to access via traditional systemic routes of drug administration, which produce significant adverse effects and result in low accumulation of drugs into the cancerous LN. To improve the survival rate of patients with LN metastasis, a lymphatic drug delivery system (LDDS) has been developed to target metastatic LN by delivering chemotherapy agents into sentinel LN (SLN) under ultrasound guidance.

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A perfusion defect in a metastatic lymph node (LN) can be visualized as a localized area of low contrast on contrast-enhanced CT, MRI or ultrasound images. Hypotheses for perfusion defects include abnormal hemodynamics in neovascular vessels or a decrease in blood flow in pre-existing blood vessels in the parenchyma due to compression by LN tumor growth. However, the mechanisms underlying perfusion defects in LNs during the early stage of LN metastasis have not been investigated.

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Lymph node (LN) metastasis is thought to account for 20-30% of deaths from head and neck cancer. The lymphatic drug delivery system (LDDS) is a new technology that enables the injection of drugs into a sentinel LN (SLN) during the early stage of tumor metastasis to treat the SLN and secondary metastatic LNs. However, the optimal physicochemical properties of the solvent used to carry the drug have not been determined.

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Cancer metastasis to lymph nodes (LNs) almost certainly contributes to distant metastasis. Elevation of LN internal pressure (intranodal pressure, INP) during tumor proliferation is associated with a poor prognosis for patients. We have previously reported that a lymphatic drug delivery system (LDDS) allows the direct delivery of anticancer drugs into the lymphatic system and is a promising treatment strategy for early-stage LN metastasis.

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Utilizing mice with swollen lymph nodes, we succeeded in irradiating individual metastatic lymph nodes through a hole in a lead shield. This system enabled us to increase the radiation dose to >8 Gy (the lethal dose for total-body irradiation) and evaluate both direct and abscopal antitumor effects.

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Therapies targeting tumor vasculature would improve the treatment of lung metastasis, although the early changes in vascular structure are incompletely understood. Here, we show that obstructive metastatic foci in lung arterioles decrease the pulmonary vascular network. To generate a mouse model of lung metastasis activation, luciferase-expressing tumor cells were inoculated into the subiliac lymph node (SiLN) of an MXH10/Mo-lpr/lpr mouse, and metastatic tumor cells in the lungs were activated by SiLN resection.

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Metastatic lymph nodes (LNs) may be the origin of systemic metastases. It will be important to develop a strategy that prevents systemic metastasis by treating these LNs at an early stage. False-negative metastatic LNs, which are found during the early stage of metastasis development, are those that contain tumor cells but have a size and shape similar to LNs that do not host tumor cells.

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Lymph node (LN) dissection is a crucial procedure for cancer staging, diagnosis and treatment, and for predicting patient survival. Activation of lung metastatic lesions after LN dissection has been described for head and neck cancer and breast cancer. Preclinical studies have reported that dissection of a tumor-bearing LN is involved in the activation and rapid growth of latent tumor metastases in distant organs, but it is also important to understand how normal (non-tumor-bearing) LN resection influences secondary cancer formation.

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Conventional treatment of lymph node metastasis involves dissection of the tumor and regional lymph nodes, but this may cause activation of latent metastatic tumor cells. However, there are few reports on animal models regarding the activation of latent metastatic tumor cells and effective methods of treating activated tumor cells. Here, we report the use of a superselective drug delivery system in a mouse model of lung metastasis in which activated tumor cells are treated with doxorubicin-encapsulated liposomes (DOX-LP) and ultrasound.

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Systemic delivery of an anti-cancer agent often leads to only a small fraction of the administered dose accumulating in target sites. Delivering anti-cancer agents through the lymphatic network can achieve more efficient drug delivery for the treatment of lymph node metastasis. We show for the first time that polymeric gold nanorods (PAuNRs) can be delivered efficiently from an accessory axillary lymph node to a tumor-containing proper axillary lymph node, enabling effective treatment of lymph node metastasis.

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Most solid cancers spread to new sites via the lymphatics before hematogenous dissemination. However, only a small fraction of an intravenously administered anti-cancer drug enters the lymphatic system to reach metastatic lymph nodes (LN). Here, we show that the enhanced permeability and retention (EPR) effect is not induced during the early stages of LN metastasis.

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