Adult bone-marrow-derived mesenchymal stem cells (MSCs) are well-established as having the capacity to differentiate into cells with mesodermal, ectodermal, and endodermal characteristics and can leave their niche to home toward and engraft within foreign tissues. To investigate whether adult MSCs contribute to the repair of skin appendages after injury, BrdU-labeled MSCs were cocultured with heat-shocked confluent sweat gland cells (SGCs) in vitro and later intravenously injected into fullthickness skin wounds in rats. When adult MSCs were cocultured with heat-shocked SGCs, a subset of adult MSCs differentiated into SGCs, the percentage of differentiation being enhanced by epidermal growth factor and the injured microenviroment, but weakened by PD98059. The ERK (extracellular signal-regulated kinase) pathway, especially pERK, was involved in the phenotype conversion of human MSCs into human SGC. Labeled MSCs were noted in hair follicles, sebaceous glands, blood vessels, and dermis in full-thickness wounds, and the incorporated cells in hair follicles and sebaceous glands were also positive for pancytokeratin. After wound healing, some labeled MSCs returned to the bone marrow, whereas other were retained in the dermis. We conclude that adult MSCs have the capacity to dock at specific sites, to contribute to wound healing of skin appendages, and to home toward marrow, and that engraftment of bone-marrow-derived cells is a functional event.

The development of drugs with rapid distribution in the kidney and long-term retention in the renal tubule is a breakthrough for enhanced treatment of acute kidney injury (AKI). Here, l-serine–modified chitosan (SC) was synthesized as a potential AKI kidney–targeting agent due to the native cationic property of chitosan and specific interaction between kidney injury molecule–1 (Kim-1) and serine. Results indicated that SC was rapidly accumulated and long-term retained in ischemia-reperfusion–induced AKI kidneys, especially in renal tubules, which was possibly due to the specific interactions between SC and Kim-1. SC-TK-SS31 was then prepared by conjugating SS31, a mitochondria-targeted antioxidant, to SC via reactive oxygen species (ROS)–sensitive thioketal linker. Because of the effective renal distribution combined with ROS-responsive drug release behavior, the administration of SC-TK-SS31 led to an enhanced therapeutic effect of SS31 by protecting mitochondria from damage and reducing the oxidative stress, inflammation, and cell apoptosis.

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Introduction The ongoing coronavirus disease 2019 (COVID-19) outbreak impacts the mental health of patients, health workers, and the public. The level of impact on the mental health of orthodontic patients in treatment is unknown. The objective of the study was to evaluate the mental health of orthodontic patients in China during the early stage of the pandemic. Methods An online survey was conducted on a convenience sample of anonymous participants. The questionnaire, in Chinese (Mandarin), comprised 5 sections. Sections 1-3 included demographic, epidemical, and orthodontic status of the patients. Section 4 assessed mental health-related to orthodontics. Section 5 was the Kessler-10 Mental Distress Scale. A total of 48 orthodontists were invited to distribute the questionnaires to their patients. Descriptive statistics, principal component analysis, K-means cluster analysis, and bivariate logistics regression analysis were performed with significance set at P <0.05. Results Questionnaires were collected from 558 patients (104 males, 354 females; mean age 24.78 ± 6.33 years). The prevalence of mental distress was 38% (174/458). Higher odds ratios were associated with female participants, missed appointments, and Hubei residence. The type of orthodontic appliance was associated with the anxiety of prolonged treatment duration. The manner of communication with patients regarding the postponement of appointments was associated with patients' concerns of prolonged treatment duration. The frequency of contact from dentists was associated with patients' independence. Conclusions Over one-third of orthodontic patients experienced mental distress during the pandemic. Multiple factors affected the level of anxiety of orthodontic patients, such as the type of orthodontic appliance, time since last dental visit, manner of communication with the orthodontist, and the localities of the pandemic progression.

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