Pancreatic islet transplantation is an effective treatment for type I diabetes mellitus. However, many problems associated with pancreatic islet engraftment remain unresolved. In this study, we ...developed a hydrogel microwell device for islet implantation, fabricated by crosslinking gelatin-methacryloyl (GelMA) and 2-hydroxyethyl methacrylate (HEMA) in appropriate proportions. The fabricated hydrogel microwell device could be freeze-dried and restored by immersion in the culture medium at any time, allowing long-term storage and transport of the device for ready-to-use applications. In addition, due to its non-swelling properties, the shape of the wells of the device was maintained. Thus, the device allowed pancreatic β cell lines to form spheroids and increase insulin secretion. Intraperitoneal implantation of the β cell line-seeded GelMA/HEMA hydrogel microwell device reduced blood glucose levels in diabetic mice. In addition, they were easy to handle during transplantation and were removed from the transplant site without peritoneal adhesions or infiltration by inflammatory cells. These results suggest that the GelMA/HEMA hydrogel microwell device can go from spheroid and/or organoid fabrication to transplantation in a single step.
Postoperative adhesion is a critical clinical issue after almost all abdominal or pelvic surgeries including liver surgery. Postoperative adhesion causes several complications, such as small bowel ...obstruction and chronic abdominal pain. Furthermore, it makes reoperation much more difficult, leading to increased mortality and morbidity rate. Postoperative adhesion is particularly problematic for repeated hepatectomy, since hepatic malignant neoplasm recurs frequently and repeated hepatectomy is widely used as one of the most curative treatments. Several treatments to reduce postoperative adhesion have been developed, which include laparoscopic surgery, administration of pharmacological agents and use of prophylactic barrier materials. However, none of them are optimal. We have proposed a novel treatment using a cell sheet of fetal liver mesothelial cells (FL‐MCs) to prevent postoperative adhesion in a novel mouse model. Besides adhesion, repeated hepatectomy has another serious problem; although the liver has a remarkable ability to regenerate, the recovery of liver mass and function of the remnant liver after multiple repeated hepatectomy is limited. The FL‐MC cell sheet enhances proliferation of hepatocytes after hepatectomy by providing growth factors for hepatocytes. Thus the FL‐MC sheet could simultaneously solve the two problems associated with repeated hepatectomy.
Cholangiocarcinoma (CC) is a type of relatively rare neoplasm in adenocarcinoma. The characteristics of CCs as well as biliary epithelial cells are heterogeneous at the different portion of the ...biliary tree. There are two candidate stem/progenitor cells of the biliary tree, i.e., biliary tree stem/progenitor cell (BTSC) at the peribiliary gland (PBG) of large bile ducts and liver stem/progenitor cell (LPC) at the canals of Hering of peripheral small bile duct. Although previous reports suggest that intrahepatic CC (ICC) can arise from such stem/progenitor cells, the characteristic difference between BTSC and LPC in pathological process needs further investigation, and the etiology of CC remains poorly understood. Here we show that Sterile alpha motif domain containing 5 (SAMD5) is exclusively expressed in PBGs of large bile ducts in normal mice. Using a mouse model of cholestatic liver disease, we demonstrated that SAMD5 expression was upregulated in the large bile duct at the hepatic hilum, the extrahepatic bile duct and PBGs, but not in proliferating intrahepatic ductules, suggesting that SAMD5 is expressed in BTSC but not LPC. Intriguingly, human ICCs and extrahepatic CCs exhibited striking nuclear localization of SAMD5 while the normal hilar large bile duct displayed slight-to-moderate expression in cytoplasm. In vitro experiments using siRNA for SAMD5 revealed that SAMD5 expression was associated with the cell cycle regulation of CC cell lines.
SAMD5 is a novel marker for PBG but not LPC in mice. In humans, the expression and location of SAMD5 could become a promising diagnostic marker for the cell type as well as malignancy of bile ducts and CCs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Near infrared (NIR) fluorescent probes are attractive tools for biomedical in vivo imaging due to the relatively deeper tissue penetration and lower background autofluorescence. Activatable probes ...are turned on only after binding to their target, further improving target to background ratios. However, the number of available activatable NIR probes is limited. In this study, we introduce two types of activatable NIR fluorophores derived from bacteriochlorin: chlorin–bacteriochlorin energy-transfer dyads and boron-dipyrromethene (BODIPY)-bacteriochlorin energy-transfer dyads. These fluorophores are characterized by multiple narrow excitation bands with relatively strong emission in the NIR. Targeted bacteriochlorin-based antibody or peptide probes have been previously limited by aggregation after conjugation. Polyethylene glycol (PEG) chains were added to improve the hydrophilicity without altering pharmacokinetics of the targeting moieties. These PEGylated bacteriochlorin-based activatable fluorophores have potential as targeted activatable, multicolor NIR fluorescent probes for in vivo applications.
Near-infrared photoimmunotherapy (NIR-PIT) is a cell-specific cancer therapy that uses an antibody-photoabsorber (IRDye700DX, IR700) conjugate (APC) and NIR light. Intravenously injected APC binds ...the target cells, and subsequent NIR light exposure induces immunogenic cell death only in targeted cells. Panitumumab and cetuximab are antibodies that target human epidermal growth factor receptor (hEGFR) and are suitable for NIR-PIT. In athymic nude mouse models, panitumumab-based NIR-PIT showed superior therapeutic efficacy compared to cetuximab-based NIR-PIT because of the longer half-life of panitumumab-IR700 (pan-IR700) compared with cetuximab-IR700 (cet-IR700). Two light exposures on two consecutive days have also been shown to induce superior effects compared to a single light exposure in the athymic nude mouse model. However, the optimal regimen has not been assessed in immunocompetent mice. In this study, we compared panitumumab and cetuximab in APCs for NIR-PIT, and single and double light exposures using a newly established hEGFR-expressing cancer cell line derived from immunocompetent C57BL/6 mice (mEERL-hEGFR cell line). Fluorescence imaging showed that the decline of pan-IR700 was slower than cet-IR700 confirming a longer clearance time. Among all the combinations tested, mice receiving pan-IR700 and double light exposure showed the greatest tumor growth inhibition. This group was also shown to activate CD8
+
T lymphocytes in lymph nodes and accumulate CD8
+
T lymphocytes to a greater extent within the tumor compared with the control group. These results showed that APCs with longer half-life and double light exposure lead to superior outcomes in cancer cell-targeted NIR-PIT in an immunocompetent mouse model.
To date, the delivery of nanosized therapeutic agents to cancers largely relies on the enhanced permeability and retention (EPR) effects that are caused by the leaky nature of cancer vasculature. ...Whereas leaky vessels are often found in mouse xenografts, nanosized agents have demonstrated limited success in humans due to the relatively small magnitude of the EPR effect in naturally occurring cancers. To achieve the superior delivery of nanosized agents, alternate methods of increasing permeability and retention are needed. Near-infrared photoimmunotherapy (NIR-PIT) is a recently reported therapy that relies on an antibody-photon absorber conjugate that binds to tumors and then is activated by light. NIR-PIT causes an increase in nanodrug delivery by up to 24-fold compared to untreated tumors in which only the EPR effect is present. This effect, termed super-EPR (SUPR), can enhance the delivery of a wide variety of nanosized agents, including nanoparticles, antibodies, and protein-binding small-molecular-weight agents into tumors. Therefore, taking advantage of the SUPR effect after NIR-PIT may be a promising avenue to use a wide variety of nanodrugs in a highly effective manner.
Background:
Near-infrared photoimmunotherapy (NIR-PIT) is a cancer therapy that causes an increase in tumor perfusion, a phenomenon termed the super-enhanced permeability and retention effect. ...Currently, in vivo treatment efficacy of NIR-PIT is observable days after treatment, but monitoring would be improved by more acute detection of intratumor change. Fluorescence imaging may detect increased tumor perfusion immediately after treatment.
Methods:
In the first experiment, athymic nude mouse models bearing unilateral subcutaneous flank tumors were treated with either NIR-PIT or laser therapy only. In the second experiment, mice bearing bilateral flank tumors were treated with NIR-PIT only on the left-sided tumor. In both groups, immediately after treatment, indocyanine green was injected at different doses intravenously, and mice were monitored with the Shimadzu LIGHTVISION fluorescence imaging system for 1 hour.
Results:
Tumor-to-background ratio of fluorescence intensity increased over the 60 minutes of monitoring in treated mice but did not vary significantly in control mice. Tumor-to-background ratio was highest in the 1 mg kg−1 and 0.3 mg kg−1 doses. In mice with bilateral tumors, tumor-to-untreated tumor ratio increased similarly.
Conclusions:
Acute changes in tumor perfusion after NIR-PIT can be detected by real-time fluorescence imaging.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Background
The perioperative mortality rate is high in patients with coronavirus disease 2019 (COVID-19), and infection control measures for medical care providers must be considered. Therefore, the ...timing for surgery in patients recovering from COVID-19 is difficult.
Case presentation
A 65-year-old man was admitted to a hospital with a diagnosis of moderate COVID-19. He was transferred to our hospital because of risk factors, including heavy smoking history, type 2 diabetes mellitus, and obesity (BMI 34). Vital signs on admission were a temperature of 36.1 °C, oxygen saturation > 95% at rest, and 94% on exertion with 3 L/min of oxygen. Chest computed tomography (CT) showed bilateral ground-glass opacities, predominantly in the lower lungs. Contrast-enhanced abdominal CT incidentally revealed a liver tumor with a diameter of 80 mm adjacent to the middle hepatic vein, which was diagnosed as hepatocellular carcinoma (HCC). After being administered baricitinib, remdesivir, dexamethasone, and heparin, the patient’s COVID-19 pneumonia improved, his oxygen demand resolved, and he was discharged on day 13. Furthermore, the patient was initially scheduled for hepatectomy 8 weeks after the onset of COVID-19 following a discussion with the infection control team. However, 8 weeks after the onset of illness, a polymerase chain reaction (PCR) test was performed on nasopharyngeal swab fluid, which was observed to be positive. The positive results persisted till 10 and 11 weeks after onset. Both Ct values were high (≥ 31) out of 45 cycles, with no subjective symptoms. Since we determined that he was no longer contagious, surgery was performed 12 weeks after the onset of COVID-19. Notably, medical staff wearing personal protective equipment performed extended anatomical resection of the liver segment 8 ventral area in a negative-pressure room. The patient had a good postoperative course, with no major complications, including respiratory complications, and was discharged on postoperative day 14. Finally, none of the staff members was infected with COVID-19.
Conclusions
We reported a case regarding the timing of surgery on a patient with persistently positive PCR test results after COVID-19, along with a literature review.
Near-infrared photoimmunotherapy (NIR-PIT) is a highly selective cancer treatment that employs an antibody photoabsorber conjugate (APC) composed of a targeting monoclonal antibody (mAb) conjugated ...with a photoactivatable phthalocyanine-derivative dye. Once injected and allowed to bind to a tumor, the APC is activated by local near-infrared light which kills cancer cells and induces a strong immune response in the tumor microenvironment by unmasking of new tumor antigens emerging from damaged tumor cells. Due to its ability to incite an immune reaction, even in poorly immunogenic tumors, NIR-PIT has the potential to enhance immunogenicity in tumors especially after immune checkpoint inhibition. In this study, we employ a poorly immunogenic MOC2-luc syngeneic tumor model and evaluate the efficacy of cancer-targeting CD44-targeted NIR-PIT. Increased infiltration of CD8+ T cells observed after NIR-PIT suggested an enhanced immune environment. Next, we evaluated tumor progression and survival after the combination of CD44-targeted NIR-PIT and short-term administration of an anti-PD1 immune checkpoint inhibitor (ICI) to further activate CD8+ T cells. Additionally, in mice in which the tumors were eradicated by this combination therapy, a re-challenge with fresh MOC2-luc cells demonstrated failure of tumor implantation implying acquired long-term immunity against the cancer cells. Combination therapy decreased tumor progression and prolonged survival significantly. Therefore, we concluded that NIR-PIT was able to convert a minimally immunogenic tumor unresponsive to anti-PD-1 ICI into a highly immunogenic tumor responsive to anti-PD-1 ICI, and this therapy was capable of inducing long-term immunity against the treated cancer.
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