Cryopreservation and the age of the allotransplant

In Vitro Models for Peripheral Nerve Regeneration

Peripheral nerve injury (PNI) resulting in lesions is highly prevalent clinically, but current therapeutic approaches fail to provide satisfactory outcomes in many patients. While peripheral nerves have intrinsic regenerative capacity, the regenerative capabilities of peripheral nerves are often insufficient to restore full functionality. This highlights an unmet need for developing more effective strategies to repair damaged peripheral nerves and improve regenerative success. Consequently, researchers are actively exploring a variety of therapeutic strategies, encompassing the local delivery of trophic factors or bioactive molecules, the design of advanced biomaterials that interact with regenerating axons, and augmentation with nerve guidance conduits or complex prostheses. However, clinical translation of these technologies remains limited, emphasizing the need for continued research on peripheral nerve regeneration modalities that can enhance functional restoration. Experimental models that accurately recapitulate key aspects of peripheral nerve injury and repair biology can accelerate therapeutic development by enabling systematic testing of new techniques. Advancing regenerative therapies for PNI requires bridging the gap between basic science discoveries and clinical application. This review discusses different in vitro models of peripheral nerve injury and repair, including their advantages, limitations, and potential applications.

Composite Tissue Preservation

Composite tissue (CT) preservation is important to outcomes after replant or transplant. Since the first limb replant, the mainstay of preservation has been static cold storage with the amputated part being placed in moistened gauze over ice. Historically, the gold-standard in solid organ preservation has been static cold storage with specialized solution, but this has recently evolved in the last few decades to develop technologies such as machine perfusion and even persufflation. This review explores the impact of cooling and oxygenation on CT, summarizes the work done in the area of CT preservation, discusses lessons learned from our experience in solid organ preservation, and proposes future directions.