Magnetic nanoparticle-induced hyperthermia with appropriate payloads: Paul Ehrlich’s “magic (nano)bullet” for cancer theranostics?

Janus nanocarriers for magnetically targeted and hyperthermia-enhanced curcumin therapy of liver cancer

Curcumin is regarded as a promising chemotherapeutic agent due to its anti-cancer activity and excellent biosafety. Nevertheless, the poor bioavailability and insufficient therapeutic efficacy have limited its further application in the clinic. Hence, we designed Janus magnetic mesoporous silica nanoparticles (Janus M-MSNs) for magnetically targeted and hyperthermia-enhanced curcumin treatment of liver cancer. In this study, curcumin was loaded into the silica components of Janus M-MSNs via surface-decorated pH-sensitive groups. Janus M-MSNs-Cur exhibited superior superparamagnetic properties, high curcumin loading ability and a tumor microenvironment-responsive curcumin release fashion. Additionally, an external magnetic field promoted the anti-tumor effectiveness of Janus M-MSNs-Cur through increasing the cellular internalization of Janus M-MSNs-Cur. More importantly, magnetic hyperthermia therapy supplemented the chemotherapeutic effect through a synergistic effect. Our outcomes demonstrated that Janus M-MSNs-Cur possessed a high therapeutic efficiency and excellent biosafety both in vitro and in vivo, indicating that Janus M-MSNs-Cur might be a promising therapeutic agent for liver cancer treatment.

Curcumin is regarded as a promising chemotherapeutic agent due to its anti-cancer activity and excellent biosafety.

Fabrication of multifunctional ferric oxide nanoparticles for tumor-targeted magnetic resonance imaging and precise photothermal therapy with magnetic field enhancement

In this study, a biocompatible nanotheranostic platform (termed as Fe₂O₃@PDA-affibody) has been constructed on the basis of coating a near-infrared light (NIR)-absorbing polydopamine (PDA) shell on oleic acid-capped superparamagnetic ferric oxide nanoparticles (Fe₂O₃ NPs) using the water-in-oil microemulsion method and then conjugated with affibody Z_IGF1R:4551, a peptide with high affinity to tumor and a polyethylene glycol (PEG) stabilizer. The Fe₂O₃@PDA-affibody integrates T₂-weighted magnetic resonance imaging (MRI), tumor-targeting, and magnetic field (MF)-enhanced photothermal therapy (PTT) functionalities into an all-in-one system. The Fe₂O₃@PDA-affibody shows high negative contrast in the MRI of an SW620 tumor bearing mouse with a decrease of 68% MRI signal, indicating that the Fe₂O₃@PDA-affibody can recognize tumor with high efficacy and specificity. Furthermore, a high accumulation ratio (>13.5% ID g^-1) and enhanced inhibition of tumor growth are achieved under near-infrared (NIR) (808 nm) laser irradiation with the aid of an external MF focused on the targeted tumor, resulting in complete eradication of mouse-borne SW620 tumors without regrowth.

Integrating Hyperthermia into Modern Radiation Oncology: What Evidence Is Necessary?

Hyperthermia (HT) is one of the hot topics that have been discussed over decades. However, it never made its way into primetime. The basic biological rationale of heat to enhance the effect of radiation, chemotherapeutic agents, and immunotherapy is evident. Preclinical work has confirmed this effect. HT may trigger changes in perfusion and oxygenation as well as inhibition of DNA repair mechanisms. Moreover, there is evidence for immune stimulation and the induction of systemic immune responses. Despite the increasing number of solid clinical studies, only few centers have included this adjuvant treatment into their repertoire. Over the years, abundant prospective and randomized clinical data have emerged demonstrating a clear benefit of combined HT and radiotherapy for multiple entities such as superficial breast cancer recurrences, cervix carcinoma, or cancers of the head and neck. Regarding less investigated indications, the existing data are promising and more clinical trials are currently recruiting patients. How do we proceed from here? Preclinical evidence is present. Multiple indications benefit from additional HT in the clinical setting. This article summarizes the present evidence and develops ideas for future research.

Design and characterisation of a phased antenna array for intact breast hyperthermia

PURPOSE

Currently available hyperthermia technology is not well suited to treating cancer malignancies in the intact breast. This study investigates a microwave applicator incorporating multiple patch antennas, with the goal of facilitating controllable power deposition profiles for treating lesions at diverse locations within the intact breast.

MATERIALS AND METHODS

A 3D-computational model was implemented to assess power deposition profiles with 915 MHz applicators incorporating a hemispheric groundplane and configurations of 2, 4, 8, 12, 16 and 20 antennas. Hemispheric breast models of 90 mm and 150 mm diameter were considered, where cuboid target volumes of 10 mm edge length (1 cm³) and 30 mm edge length (27 cm³) were positioned at the centre of the breast, and also located 15 mm from the chest wall. The average power absorption (αPA) ratio expressed as the ratio of the PA in the target volume and in the full breast was evaluated. A 4-antenna proof-of-concept array was fabricated and experimentally evaluated.

RESULTS

Computational models identified an optimal inter-antenna spacing of 22.5° along the applicator circumference. Applicators with 8 and 12 antennas excited with constant phase presented the highest αPA at centrally located and deep-seated targets, respectively. Experimental measurements with a 4-antenna proof-of-concept array illustrated the potential for electrically steering power deposition profiles by adjusting the relative phase of the signal at antenna inputs.

CONCLUSIONS

Computational models and experimental results suggest that the proposed applicator may have potential for delivering conformal thermal therapy in the intact breast.