Clinical application of small-diameter artificial blood vessels of 6 mm or less remains challenging. We investigated whether small-diameter blood vessels can be regenerated using the patient's own cells. We focused on adipose tissue-derived mesenchymal stem cells（MSCs）as the cell source. MSCs have shown to differentiate into vascular endothelial cells and become part of cardiomyocytes. Cells were obtained and cultured from surgically-removed adipose tissue. After two passages, cells were subjected to in-vitro differentiation induction experiments into adipose, bone, and cartilage tissues. Cells, after trypsinization, were seeded onto a 3 cm×5 cm PGA sheet and cultured for 7 days using a vascular differentiation induction medium. The cultured cells/PGA sheet were then wrapped circumferentially around a 7 mm diameter silicone tube and implanted subcutaneously in the back of nude mice. After 6-8 weeks, the mice were sacrificed and the bioengineered vessels were harvested. These were evaluated using H&E staining, EVG, and CD31 immunohistochemical staining, and compared with native human blood vessels. The cells isolated from adipose tissue through enzymatic treatment, regardless of age and gender, formed colonies on plastic culture dishes within 5-7 days of cultivation, with fibroblast-like spindle-shaped cells proliferating. In differentiation experiments, osteoblasts, adipocytes, and chondrocytes formation were confirmed. The biovessels implanted subcutaneously in the back of the nude mice resembled tubular blood vessels macroscopically. H&E staining showed vascular-like findings, and although limited, EVG and CD31-positive tissues were also observed. Adipose-derived stem cells demonstrated multipotency, and parts of the engineered tissues created using tissue engineering techniques regenerated vascular tissue. In the future, we aim to optimize the culture duration and conditions to produce small-diameter bioengineered vessels with high antithrombotic properties from adipose-derived MSCs using tissue engineering techniques.

Background: Mental health of university students has become a significant concern; however, research focused on international students who may be at a higher risk of mental health challenges is insufficient. This study aimed to elucidate the current mental health status and barriers to accessing mental health care for international students in Japan by comparing them for Japanese students.

Methods: This cross-sectional study used an online survey targeting Japanese and international students at Sophia University in Tokyo, Japan. The survey compared demographics, such as age, sex, and Japanese language proficiency, along with current healthcare access and challenges, Patient Healthcare Questionnaire（PHQ）-8, Generalized Anxiety Disorder（GAD）-7, Alcohol Use Disorders Identification Test（AUDIT）-C, and the brief resilience scale between Japanese and international students. Multiple regression analysis was conducted to examine the mental health status of international students, whereas multivariate logistic regression analysis was conducted to explore the risks of healthcare access barriers.

Results: We obtained 133 valid responses, 83 from Japanese students and 50 from international students. After adjusting for covariates, international students showed significantly higher PHQ-8（p＝0.005）and GAD-7（p＜0.001）scores than Japanese students. Being an international student in Japan was not a risk factor for barriers to healthcare access, but low Japanese speaking proficiency（p＝0.037）and high resilience（p＝0.047）were significant risk factors. Among mental health challenges, 68% of international students identified Japanese language proficiency as the primary challenge.

Conclusion: International students exhibited significantly higher levels of depression and anxiety than Japanese students. Being an international student was not a risk factor for barriers to healthcare access; however, the results suggested a potential association between Japanese ability and healthcare access.