Nano-Cryosurgery: A Basic Way to Enhance Freezing Treatment of Tumor

Cryosurgery is a minimally invasive clinical technique with controlled destruction of target tissues through a specifically administrated freezing procedure. This method has now been used in a wide variety of clinical situations such as treatment of skin cancers, glaucoma, lung and prostate tumor etc. However, there still exist many bottle necks to impede the success of a cryosurgery. A most critical factor has been that insufficient or inappropriate freezing will not completely destroy the target tumor tissues, which as a result may lead to tumor regenesis and thus failure of treatment. Meanwhile, the surrounding healthy tissues may suffer from serious freeze injury due to unavoidable release of a large amount of cold from the freezing probe. To resolve this difficulty, we proposed an innovative strategy, termed as nano-cryosurgery, to significantly improve freezing efficiency of a conventional cryosurgical procedure. The basic principle of this protocol is to inject functional solution with nano particles into the target tissues, which then serves as either to maximize the freezing heat transfer process, regulate freezing scale, modify ice-ball formation orientation or prevent the surrounding healthy tissues from being frozen. Meanwhile, introduction of nanoparticles during cryosurgery could also help better image the edge of a tumor as well as the margin of the iceball. Along this direction, several progresses have been made on mechanism interpretation, theoretical modeling, numerical prediction, conceptual experimental demonstration and treatment planning etc. in the authors’ lab. This study is dedicated to present a preliminary outline on the nano-cryosurgery by summing up the aspects as mentioned above. The evident merits and shortcomings of the nano cryosurgery will be illustrated. Some potential feasibility, versatile applications and possible challenges when nanotechnology meets cryosurgery will be pointed out. It is expected that the concepts of nano-cryosurgery may suggest new opportunities for realizing a highly safe, targeted and accurate freezing therapy in future tumor clinics.