Combination of bone marrow mesenchymal stem cells and moxibustion restores cyclophosphamide-induced premature ovarian insufficiency by improving mitochondrial function and regulating mitophagy.

BACKGROUND: Premature ovarian insufficiency (POI) is a major cause of infertility. In this study, we aimed to investigate the effects of the combination of bone marrow mesenchymal stem cells (BMSCs) and moxibustion (BMSCs-MOX) on POI and evaluate the underlying mechanisms. METHODS: A POI rat model was established by injecting different doses of cyclophosphamide (Cy). The modeling of POI and the effects of the treatments were assessed by evaluating estrous cycle, serum hormone levels, ovarian weight, ovarian index, and ovarian histopathological analysis. The effects of moxibustion on BMSCs migration were evaluated by tracking DiR-labeled BMSCs and analyzing the expression of chemokines stromal cell-derived factor 1 (Sdf1) and chemokine receptor type 4 (Cxcr4). Mitochondrial function and mitophagy were assessed by measuring the levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), ATP, and the mitophagy markers (Drp1, Pink1, and Parkin). Furthermore, the mitophagy inhibitor Mdivi-1 and the mitophagy activator CCCP were used to confirm the role of mitophagy in Cy-induced ovarian injury and the underlying mechanism of combination therapy. RESULTS: A suitable rat model of POI was established using Cy injection. Compared to moxibustion or BMSCs transplantation alone, BMSCs-MOX showed improved outcomes, such as reduced estrous cycle disorders, improved ovarian weight and index, normalized serum hormone levels, increased ovarian reserve, and reduced follicle atresia. Moxibustion enhanced Sdf1 and Cxcr4 expression, promoting BMSCs migration. BMSCs-MOX reduced ROS levels; upregulated MMP and ATP levels in ovarian granulosa cells (GCs); and downregulated Drp1, Pink1, and Parkin expression in ovarian tissues. Mdivi-1 significantly mitigated mitochondrial dysfunction in ovarian GCs and improved ovarian function. CCCP inhibited the ability of BMSCs-MOX treatment to regulate mitophagy and ameliorate Cy-induced ovarian injury. CONCLUSIONS: Moxibustion enhanced the migration and homing of BMSCs following transplantation and improves their ability to repair ovarian damage. The combination of BMSCs and moxibustion effectively reduced the excessive activation of mitophagy, which helped prevent mitochondrial damage, ultimately improving ovarian function. These findings provide a novel approach for the treatment of pathological ovarian aging and offer new insights into enhancing the efficacy of stem cell therapy for POI patients.

Preservation of Anticancer and Immunosuppressive Properties of Rapamycin Achieved Through Controlled Releasing Particles.

Rapamycin is commonly used in chemotherapy and posttransplantation rejection suppression, where sustained release is preferred. Conventionally, rapamycin has to be administered in excess due to its poor solubility, and this often leads to cytotoxicity and undesirable side effects. In addition, rapamycin has been shown to be hydrolytically unstable, losing its bioactivity within a few hours. The use of drug delivery systems is hypothesized to preserve the bioactivity of rapamycin, while providing controlled release of this otherwise potent drug. This paper reports on the use of microparticles (MP) as a means to tune and sustain the delivery of bioactive rapamycin for up to 30 days. Rapamycin was encapsulated (100% efficiency) in poly(lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), or a mixture of both via an emulsion method. The use of different polymer types and mixture was shown to achieve a variety of release kinetics and profile. Released rapamycin was subsequently evaluated against breast cancer cell (MCF-7) and human lymphocyte cell (Jurkat). Inhibition of cell proliferation was in good agreement with in vitro release profiles, which confirmed the intact bioactivity of rapamycin. For Jurkat cells, the suppression of cell growth was proven to be effective up to 20 days, a duration significantly longer than free rapamycin. Taken together, these results demonstrate the ability to tune, sustain, and preserve the bioactivity of rapamycin using MP formulations. The sustained delivery of rapamycin could lead to better therapeutic effects than bolus dosage, at the same time improving patient compliance due to its long-acting duration.