A microneedle array is an attractive option for a minimally invasive means to break through the skin barrier for efficient transdermal drug delivery. Here, we report the applications of solid polymer-based ion-conductive porous microneedles (PMN) containing interconnected micropores for improving iontophoresis, which is a technique of enhancing transdermal molecular transport by a direct current through the skin. The PMN modified with a charged hydrogel brings three innovative advantages in iontophoresis at once: (1) lowering the transdermal resistance by low-invasive puncture of the highly resistive stratum corneum, (2) transporting of larger molecules through the interconnected micropores, and (3) generating electroosmotic flow (EOF). In particular, the PMN-generated EOF greatly enhances the transdermal molecular penetration or extraction, similarly to the flow induced by external pressure. The enhanced efficiencies of the EOF-assisted delivery of a model drug (dextran) and of the extraction of glucose are demonstrated using a pig skin sample. Furthermore, the powering of the PMN-based transdermal EOF system by a built-in enzymatic biobattery (fructose / O2 battery) is also demonstrated as a possible totally organic iontophoresis patch.

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19) and the ensuing worldwide pandemic. The spread of the virus has had global effects such as activity restriction, economic stagnation, and collapse of healthcare infrastructure. Severe SARS-CoV-2 infection induces a cytokine storm, leading to acute respiratory distress syndrome (ARDS) and multiple organ failure, which are very serious health conditions and must be mitigated or resolved as soon as possible. Mesenchymal stem cells (MSCs) and their exosomes can affect immune cells by inducing anti-inflammatory macrophages, regulatory T and B cells, and regulatory dendritic cells, and can inactivate T cells. Hence, they are potential candidate agents for treatment of severe cases of COVID-19. In this review, we report the background of severe cases of COVID-19, basic aspects and mechanisms of action of MSCs and their exosomes, and discuss basic and clinical studies based on MSCs and exosomes for influenza-induced ARDS. Finally, we report the potential of MSC and exosome therapy in severe cases of COVID-19 in recently initiated or planned clinical trials of MSCs (33 trials) and exosomes (1 trial) registered in 13 countries on ClinicalTrials.gov.

Mucosal-associated invariant T (MAIT) cells are innate-like T cells involved in anti-bacterial im-munity. Recent studies have demonstrated that MAIT cells might be implicated in inflammatory bowel diseases (IBDs), but their precise function in IBD remains to be elucidated. We investigated the possible involvement of MAIT cells in the immunopathogenesis of IBDs. Heparinized peripheral blood and biopsy specimens of the colon were collected from 25 patients with ulcerative colitis (UC), 15 patients with Crohn's disease (CD), and 19 heathy individuals. Lymphocytes were isolated from the blood and colon, and then MAIT cells were analyzed by flow cytometry. The frequency of MAIT cells was significantly lower in the blood of IBD patients compared to healthy donors and significantly higher in the inflamed colons compared to healthy colons (P = 0.001). Among the IBD patients, the frequency of MAIT cells in the blood and colon was correlated with disease activities. In vitro activated MAIT cells from IBD patients secreted significantly more tumor necrosis factor-α and interleukin-17 than those from healthy donors. These findings indicate that MAIT cells are activated in IBD patients, and their accumulation in the inflamed mucosa is correlated with disease activities.Inflammatory bowel diseases (IBDs), including ulcerative colitis (UC) and Crohn's disease (CD), are chronic, relapsing inflammatory conditions of the gastrointestinal tract. Although host genetic susceptibility and environmental factors have been implicated in causing the disturbed homeostasis of the intestinal immune system that results in IBD, the exact etiology of IBD is still unknown (11,19,20). Genetic variants clearly play a central role in conferring risk for IBD, but a wide range of environmental factors, including smoking, diet drugs, social stress, and microbial factors, are also thought to confer risk for IBD (2). Accumulating evidence has suggested that among those environmental factors, the dynamic balance between commensal flora and host defensive responses within the intestinal mucosa plays a pivotal role in both the initiation and per-

Aim: Hepatocellular carcinoma (HCC) is frequently complicated with cirrhosis, and it is not unusual for treatment options to be limited as a result of pancytopenia due to hypersplenism. Partial splenic embolization (PSE) has been performed for thrombocytopenia resulting from hypersplenism. We studied the efficacy in terms of hepatic functional reserve and safety in patients who underwent concurrent transcatheter arterial chemoembolization (TACE) with PSE for HCC. Methods:The study population consisted of 101 HCC patients with thrombocytopenia. Fifty-three patients were treated with concurrent TACE/PSE (PSE group), and the remaining 48 TACE patients without PSE (non-PSE group) were investigated hepatic functional reserve.

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These findings suggested that MAIT cells were activated, exhausted, and persistently depleted in PBC patients even after ursodeoxycholic acid treatment, possibly as a consequence of persistent liver inflammation.

Background and Aim: Recent studies have demonstrated that B cells and follicular helper T (Tfh) cells, which are central regulators of humoral immune response, contribute to the development and progression of autoimmune diseases. Because Tfh cells can be divided into several subsets with distinct functional properties, this study aimed to examine the roles of different subsets of circulating Tfh cells in the immune pathogenesis of autoimmune hepatitis (AIH). Methods: Thirty-five patients with AIH, 28 patients with primary biliary cholangitis, 22 patients with chronic hepatitis B (CHB), and 44 health controls (HC) were enrolled. The frequencies of different Tfh subsets in the blood and liver were examined by flow cytometry and immunohistochemical staining. The function of circulating Tfh subsets was examined after in vitro stimulation. Results: In newly diagnosed AIH patients, the frequency of circulating chemokine C-C receptor 7À programmed cell death-1 + Tfh subset was significantly increased compared with that in CHB patients and HC, significantly correlated with clinical parameters, including serum IgG, prothrombin time and albumin levels, and significantly decreased after corticosteroid treatment. In the liver of AIH patients, the frequencies of activated Tfh subsets were significantly increased and positively correlated with those in the blood. Moreover, the ability to produce interleukin-21 and interleukin-17 from circulating Tfh cells was significantly increased in AIH patients compared with HC. Conclusions: These results significantly extend our understanding of Tfh subsets in AIH and suggest a potential role of dysregulated chemokine C-C receptor 7À programmed cell

An array of porous microneedles (PMNs) made of biodegradable poly(lactic-co-glycolic acid) (PLGA) is fabricated by a combination of molding and freeze-drying methods. The optimized mixture of PLGA and 1,4-dioxane is poured into a mold of a microneedle array, followed by the freezing and sublimation of the frozen particles of 1,4-dioxane, a procedure that left an interconnecting porous structure in the PLGA with a porosity around 50%. The mechanical strength of the PMN made of PLGA (PLGA-PMN) is reinforced by modification with carboxymethylcellulose (CMC), resulting in sufficient strength enough for insertion into an excised porcine skin. The transdermal resistance is significantly decreased by the CMC-modified PLGA-PMN, which would improve the efficiency and safety of DC current-based transdermal techniques, including the electrical monitoring of the skin condition and iontophoresis for drug delivery and medical diagnosis.