Radiolabeling method for personalised cancer treatment

Table of Content

• What is personalised medicine?

• The three Eras of medicine

• Early chemotherapy, its advantages and disadvantages

• Method of drug delivery using radiolabelling technology

• Comparison with chemotherapy

• Newer advances in personalised cancer treatment

• Take-Home Points

• FAQ on Radiolabeling method for personalised cancer treatment

Introduction

In radiolabeled treatment, the treatment of cancer is done using antibodies which are labelled with certain radioactive nuclei that emit nanoparticles. When these antibodies move to a tumour site to bind with the receptors of tumour cells, the concentration of radiolabeled antibodies at that site increases significantly. These radioactive nuclei help know the tumour location and metastasis and produce therapeutic effects. These produce radiation from a nearby location without actually exposing other organs to these harmful radiations as in previous radiotherapy techniques. This helps us to know the site of the tumour as well as the tumour load. These are not as toxic as the previous radiotherapy so they can be used many times. The first scientist to use radio tracing was Von Hevesy. In 1911 he started to use radio tracing in the separation of radium d from lead. But he made significant progress in 1913.

Mechanism- The mechanism differs with the different treatments. The mechanism of radio labelling of iodine involves reactive iodine which is generated by the oxidation of isotopic sodium iodide which reacts like an electrophilic reagent using tyrosyl groups on the protein.

What is personalised medicine?

In personalized treatment, the purpose is to get the genetic information of different patients by biomarkers or genetic tests. Accordingly, the same treatment will be given to the population of similar genetics. This will increase the efficacy of treatment and will decrease the side effects. Earlier we used to give the same kind of medication to all patients. Some were treated, and others didn't respond to the same medication. This creates the need for personalized treatment. The best use of this can be seen in treating cancers. Since chemotherapy can be useful for metastatic tumours also but is very toxic to some patients and less effective in others. Therefore a radiolabeled method for personalized treatment is preferred over personalized chemotherapy.

The three Eras of medicine

• Era-1: In ancient times, doctors used to treat cancer by surgery and many times it was ineffective and proved to be fatal. They also used cautery to treat cancer. The main reason for their ineffectiveness is metastasis and rapid growth. Even some surgeries help in tumour invasion. It was based on blind laws.

• Era-2: In this era, doctors started to consider the role of emotions and thoughts to keep the person healthy and make a patient better. This was the era of attitude, thoughts and beliefs.

• Era-3: This era is based on the development of the non-local mind. Also known as infinite medicine. It believes that treatment can be done at a distance through love, thoughts and prayers.

Early chemotherapy, its advantages and disadvantages

Initially, surgery was the first-line treatment in cancer patients. After that radiation plays the role to treat those tumours which were not surgically removed. Ultimately chemotherapy was discovered. Earlier there were chemical weapons used especially in war, so scientists were working to get stronger and cheaper chemical weapons. Many of them are the derivatives of nitrate and mustard gas. Eventually, the nitrogen-derived compound was very useful in treating cancer of lymph nodes. Subsequently, many compounds related to it were found which were more effective like alkylating agents. They damage the DNA DNA of cancer cells and help in preventing the uncontrolled growth of tumour cells. There were many more discoveries which led to the development of methotrexate which can be used to treat many cancers, even metastatic tumours. 

Advantages  of chemotherapy

• It can go to the tumour site anywhere in the body.

• Testicular tumours, leukaemia and lymphoma are successfully treated by chemotherapy.

Disadvantages of chemotherapy

• It may damage rapidly dividing cells in the bone marrow.

• Therefore causing anaemia, leukopenia, etc.

• It also causes nausea, vomiting, and gastrointestinal upset, hair loss.

Method of drug delivery using radiolabelling technology

1. Liposomes: It is used to deliver drugs against the tumour at the specific site. It is encapsulated which does not allow degradation before it is required. It protects the drug from other reactive molecules.

2. Solid lipid nanoparticles: It has a lipophilic matrix in which the drug is dissolved. It contains melted lipids. Monoglycerides, triglycerides, triglycerides, and other fatty acids can be used to make solid lipid nanoparticles.

3. Dendrimers: These are the molecules that have many branches arising from the centre. These are made from amino acids, sugars, and nucleotides. The drug is filled in the centre of dendrimers.

4. PNPs: These are nano-sized and solid. It can be nanospheres or nanocapsules. It is formed via two steps: dispersion of preformed chemicals and direct polymerisation.

Comparison with chemotherapy

They have better therapeutic effects. Many different drugs for cancer treatment can be included in the same nanoparticle. These are not associated with the side effects like gastrointestinal upset which are commonly seen in chemotherapy. Personalized medicine cancer treatment provides the specific treatment that is most suitable to that particular patient. But there is a risk for non-specific radiation that can arise from nuclear medicine. There is no bone marrow suppression in personalized medicine cancer treatment. The radionuclide acts as a radiotracer having high sensitivity as compared to fluorescence. It has high reliability, accuracy and successful results. It has the property of penetrating deep inside. There are some challenges in radio labelling treatment like it has not been the part of complete treatment of cancer like other therapies. There have been 97% failure of trials for targeted cancer treatment. Also, there is a perception of fear of radiation. These techniques are contraindicated in pregnant, breastfeeding women and carcinoma with no iodine uptake.

Newer advances in personalised cancer treatment

1. Recently the development is seen in radiolabeled antibodies using indium, iodine, and technetium. The antibodies reduce in vivo dehalogenation of radioisotopes to prevent the gut from radiation. Recent antibodies have developed which results in less hepatic exposure to such radiations.

2. The key target in treating Parkinson's disease and heart failure is the norepinephrine transporters. Many radioactive molecules which target norepinephrine transporters have been developed.

3. Advancement in brachytherapy using radionuclide nanoparticles- It is especially used in the treatment of prostate cancer. In which nuclear medicines are placed permanently inside the prostate. It has been successfully placed in many centres.

4. The radiolabeled ligand has shown to be a potential radiopharmaceutical therapy by modifying molecular structures and changing their binding selectivity to their specific tumour receptors.

Take-Home Points

Personalised medicine cancer treatment has been proven to be a safe, effective and efficient way of radioimmunotherapy. In this, theranostics molecules containing cancer personalised medicine are moved to a tumour site emitting radiations directly from the nearby location. Hence preventing other organs’ exposure to such invasive cancers. Recently the Food and Drug Administration of the USA has approved much-personalised medicine cancer treatment using radioactive nanomaterials as its potential in personalised treatment of Cancer patients is being recognized. Although the main problem is the emission of non-specific radiation in the tissues which has a potential risk of causing mutation in the DNA base pairs and may lead to the growth of more aggressive cancer.