Quadropeutics: a quadruple blow to the tumor
American researchers working under the leadership of Dmitry Lapotko from Rice University conducted the first preclinical study of an innovative approach to cancer treatment, consisting in combining four existing therapies and called "quadropeutics".
According to Lapotko, quadropeutics differs from other methods of antitumor therapy in that it allows selectively enhancing the effects of drugs and ionizing radiation inside malignant cells. This is achieved through mechanical action – externally controlled tiny explosions, called "plasmon nanobubbles".
In earlier experiments, the authors demonstrated the ability of "nanobubbles" to literally explode cells. In their new work, the researchers used them to identify and destroy cancer cells using three mechanisms. In cells that have survived the mechanical effects of "explosions", bursting nanobubbles significantly enhance the local effects of chemotherapy drugs and ionizing radiation. All three mechanisms are triggered exclusively inside malignant cells and do not damage the surrounding healthy tissues.
The first component of quadropeutics is a small dose of an encapsulated form of a chemotherapy drug (the authors tested doxorubicin and paclitaxel) labeled with antibodies specific to cancer cells. Due to the enhancing effect of nanobubbles, the activity of the drug is manifested when doses are administered that are only a few percent of the standard therapeutic dosage.
The second component is a non-toxic injection solution of colloidal gold, traditionally used in the treatment of arthritis. Labeled with tumor-specific antibodies, the smallest spherical gold particles accumulate and form aggregates inside tumor cells. Initially inert, they are activated by laser or ionizing radiation.
The third component is a short pulse of laser radiation in the near infrared region of the spectrum, the power of which is a million times lower than the power of a conventional surgical laser. This pulse is delivered to the tumor using a standard endoscope, where gold nanoclusters transform the energy of the light flux into plasmon nanobubbles.
The fourth component is a low single dose of radioactive radiation. Gold nanoclusters selectively enhance the destructive effect of radiation inside malignant cells, even if the total dose of ionizing radiation is only a few percent of the usual clinical dose.
As part of their latest study, the authors tested the effectiveness of the new approach on laboratory and mouse models of human squamous cell carcinoma of the head and neck, resistant to chemo and radiotherapy. According to the authors, the effectiveness of the "quadropeutic" protocol exceeds the effectiveness of the standard protocol for the treatment of this form of the disease in the laboratory model 100% times and in the animal model – 17 times. At the same time, the use of only 3% of the traditional dosage of the chemotherapy drug and 6% of the traditional dose of radioactive radiation destroyed tumors in the body of mice within a week.
Currently, the authors are doing everything possible to speed up the clinical trials of the approach they have developed. They claim that it is a universal technology potentially applicable for the treatment of various types of solid tumors, including intractable forms of brain, lung and prostate cancer.
Article by Ekaterina Y. Lukianova-Hleb et al. On-demand intracellular amplification of chemoradiation with cancer-specific plasmonic nanobubbles is published in the journal Nature Medicine.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Rice University:
‘Quadrapeutics’ works in preclinical study of hard-to-treat tumors.
02.06.2014