Mitochondria are double-membrane organelles that are involved in energy production, apoptosis, and signaling in eukaryotic cells. Several studies conducted over the past decades have correlated mitochondrial dysfunction with various diseases, including cerebral ischemia, myocardial ischemia-reperfusion, and cancer. Mitochondrial transplantation entails importing intact mitochondria from healthy tissues into diseased tissues with damaged mitochondria to rescue the injured cells. In this review, the different mitochondrial transplantation techniques and their clinical applications have been discussed. In addition, the challenges and future directions pertaining to mitochondrial transplantation and its potential in the treatment of diseases with defective mitochondria have been summarized.

Radiotherapy serves as a cornerstone of cancer treatment, but its efficacy is often compromised by radioresistance, a process in which cancer-associated fibroblasts (CAFs) play a critical role. Following irradiation, CAFs exhibit inherent radioresistance, not only surviving at higher doses but also undergoing profound functional reprogramming, including senescence, acquisition of a senescence-associated secretory phenotype (SASP), and myofibroblast activation. Importantly, CAFs employ multiple interconnected mechanisms to collectively drive radioresistance: sustained immunosuppression, pro-resistance paracrine signaling, exosome-mediated communication, and stromal remodeling. These reprogrammed CAFs create a microenvironment that paradoxically supports tumor recurrence and limits therapeutic efficacy. Intervention strategies targeting CAFs—including neutralizing soluble factors, blocking key signaling nodes, targeted therapies against fibroblast activation proteins, or disrupting exosome-mediated communication—have shown promise in preclinical studies. A deeper understanding of the complex interactions between radiotherapy and CAFs may ultimately drive a shift in therapeutic strategy from targeting tumor cells alone to leveraging the entire microenvironment to achieve durable antitumor effects.