Developing means to improve cryosurgery monitoring: A miniature wireless implantable temperature sensor and a temperature-field reconstruction technique (original) (raw)

One such option is that of cryoablation, yet its utilization in the treatment of MCT has not been extensively explored. Cryoablation has been shown to be a highly effective therapeutic approach for the treatment of various human cancers and has been shown to provide multiple benefits over traditional surgery. Accordingly, in this study we examined the use of cryoablation for the treatment of MCT, focusing investigations into the response of MCT cells to low temperature insults. Further, we investigated the potential of the combinatorial approach of freezing and vitamin D3 (VD3) cryosensitization. We have previously published on the use of VD3 (calcitriol) as a cryosensitizer both in vitro and in a murine prostate cancer model. We hypothesized that the combination of calcitriol as an adjunctive agent to MCT cryotreatment would result in increased cell death following a mild freeze exposure, thereby proving to be beneficial to overall cancer eradication. The C2 canine mastocytoma cell line was exposed to temperatures ranging from À5 to À25°C and cell viability was assessed via the metabolic activity indicator alamarBlue. Regardless of exposure time (3, 5, or 10 min), the À5 and À10°C freezes resulted in negligible cell loss (<5%). However, the À15°C isotherm resulted in 20%, 50%, and 70% cell loss respective to the freeze hold time of 3, 5, or 10 min. Similarly, the À20°C isotherm also revealed an exposure time-dependent cell death effect, with 10%, 3%, and 0% of initial populations remaining 24 h post-freeze, respectively. Temperatures of À25°C, regardless of freeze time, were required to induce cell death in the entire population (no re-growth observed). This indicates that time is a critical factor in C2 cell ablation at temperatures between À15 and À20°C, but less of a factor in the warmer or colder thermal zones. Studies into the efficacy of VD3 cryosensitization in the C2 MCT cells revealed that pretreatment of cultures for 24 h with 1, 5, 10, or 25 nM calcitriol followed by 5 min cryoexposure to À10, À12, or À15°C yielded a decrease in cell viability. The effect was the most noticeable at À15°C, where a [1 nM] calcitriol cryosensitization regime decreased viability 50% over freezing alone. The data from this study provides a characterization of the freeze response of MCT cells, which is an important step towards veterinary clinical utilization. Further, these findings suggest that the utilization of vitamin D3 as a cryoadjuvant may have benefits in cancer therapy. Funding: This project was supported by CPSI Biotech. Conflict of interest: None declared.