Thermochemical ablation therapy of VX2 tumor using a permeable oil-packed liquid alkali metal

Emerging Liquid Metal Biomaterials: From Design to Application

Liquid metals (LMs) as emerging biomaterials possess unique advantages including their favorable biosafety, high fluidity, and excellent electrical and thermal conductivities, thus providing a unique platform for a wide range of biomedical applications ranging from drug delivery, tumor therapy, and bioimaging to biosensors. The structural design and functionalization of LMs endow them with enhanced functions such as enhanced targeting ability and stimuli responsiveness, enabling them to achieve better and even multifunctional synergistic therapeutic effects. Herein, the advantages of LMs in biomedicine are presented. The design of LM-based biomaterials with different scales ranging from micro-/nanoscale to macroscale and various components is explored in-depth to promote the understanding of structure-property relationships, guiding their performance optimization and applications. Furthermore, the related advanced progress in the development of LM-based biomaterials in biomedicine is summarized. Current challenges and prospects of LMs in the biomedical field are also discussed.

Image-guided chemistry altering biology: An in vivo study of thermoembolization

RATIONALE

Advances in image-guided drug delivery for liver cancer have shown a significant survival benefit. However, incomplete treatment is common and residual disease is often found in explanted liver specimens. In addition, the need to treat a malignancy from multiple mechanisms at the same time for optimal outcomes is becoming more widely appreciated. To address this, we hypothesized that an exothermic chemical reaction could be performed in situ. Such a strategy could in principle combine several angles of attack, including ischemia, hyperthermia, acidic protein denaturation, and metabolic modulation of the local environment.

METHODS

The University of Texas MD Anderson Cancer Center Institutional Animal Care and Use Committee approved this study. Outbred swine (25-35 kg, 5 control and 5 experimental) were treated under general anesthesia. Embolization was performed with coaxial microcatheter technique in a segmental hepatic arterial branch using either ethiodized oil as control or with thermoembolic solutionBlood samples were obtained before, immediately after, and the day following the procedure just before CT scans and euthanasia. Livers were explanted and samples were obtained for histologic analysis.

RESULTS

All animals survived the procedure and laboratory values of the control and experimental groups remained within normal limits. The control group had a diffuse or cloudy pattern of attenuation on follow-up CT scan the day after, consistent with gradual antegrade sinusoidal transit of the embolic material. The experimental group had clearly defined vascular casts with some degree of peripheral involvement. At histology, the control group samples had the appearance of normal liver, whereas the experimental group had coagulative necrosis in small pale, punctate areas extending several hundred microns away from the treated vessels and a brisk inflammatory response just outside the margins.

CONCLUSION

In situ chemistry via thermoembolization shows early promise as a fundamentally new tactic for image-guided therapy of solid tumors.

NaK alloy-induced in vivo tumor ablation therapy

PURPOSE

Alkali metal ablation is newly emerging as an effective, economic and minimally invasive ablation therapy. This study is dedicated to demonstrate the high efficiency of NaK alloy ablation on in vivo tumors with different stages in mice.

MATERIAL AND METHODS

Panc02 tumor cells were injected into 21 female C57B/L mice, which were divided into three groups. Two experimental groups of mice received the same percutaneous NaK alloy injection for a week apart. The inner temperature response and surface temperature distribution were measured using a thermal couple and an infrared camera. After each ablation experiment, two mice in each group were chosen randomly to make pathological sections. The tumor volumes were measured once every two days. At the end, all tumors were cut off to calculate the tumor inhibition rates.

RESULTS

The NaK alloy-induced ablation therapy produced an obvious temperature increase (85 °C) in the ablation region and the high temperature distribution was relatively concentrated. The histopathology sections showed that developing stage tumors received incomplete destruction of the malignant cells compared with early stage tumors. The tumor inhibition rate in the early and developing tumor treatment groups were 88.5% and 67.6%, respectively.

CONCLUSIONS

This technology provides a nearly thorough ablation treatment for early stage tumors and also a palliative treatment for developing tumors.