Advancements in Neurological Disease Treatment
Researchers at the National Autonomous University of Mexico (UNAM) in Baja California are pioneering a groundbreaking technology aimed at enhancing the diagnosis and treatment of various neurological and neurodegenerative diseases, including Parkinson’s, Alzheimer’s, epilepsy, and multiple sclerosis, as well as certain types of cancer. This innovative project, spearheaded by scientists from the Centre for Nanosciences and Nanotechnology (CNyN) at the UNAM Ensenada campus, focuses on transforming plant and bacterial viruses into organic vehicles measuring between 20 and 60 nanometres. These nanocarriers are designed to transport and deposit therapeutic substances directly into specific tumours or tissues within the human body. Experts believe that these nanovehicles could usher in new possibilities for implementing theranostics—a method that integrates diagnosis and treatment to simultaneously locate and target diseased cells.
One of the significant challenges in neuromedicine is overcoming the blood-brain barrier, a protective structure that prevents harmful substances from entering the brain but also hinders the delivery of medications. Rafael Vázquez Duhalt, a researcher at CNyN, highlighted that the brain’s protective barrier allows only about 0.2 to 2% of administered drugs to penetrate this critical organ. Currently, to ensure that treatments reach affected brain tissues, high systemic doses are utilised. However, this approach can reduce the efficacy of medications and lead to adverse side effects due to the exposure of healthy organs to potentially harmful substances.
Innovative Nanoparticle Development
The UNAM team aims to address this issue by developing nanoparticles constructed from plant viruses and bacteriophages—viruses that infect bacteria—which are characterised by their safety and biocompatibility with humans. Rubén Darío Cadena, another researcher from CNyN, explained that the team harnesses the natural properties of the proteins that encapsulate the viral material, replacing the infectious genetic material with therapeutic drugs. “We mimic natural processes. Viruses are essentially a protein shell at the nanoscale with genetic material inside. We remove the infectious content and replace it with drugs, resulting in virus-like particles (VLPs),” he stated. The protein layer, known as the capsid, safeguards the therapeutic molecule and prevents its degradation.
A notable feature of this technology is that, after the particles are manufactured, researchers employ bionanotechnology techniques to modify their surfaces and incorporate molecules that the blood-brain barrier recognises, facilitating the entry of the nanovehicles into the brain. Vázquez Duhalt emphasised that “this technology presents the opportunity to deliver drugs to specific organelles, such as the mitochondria, the internal structures of cells. This allows us to reduce dosages and direct treatments where they are most needed. It represents a much more intelligent form of medicine, which is already in development.”
Combating Cancer with Targeted Therapies
The university researchers assert that the properties of these nanoparticles could also enhance cancer treatments and facilitate the development of therapies aimed at preventing potential relapses. Kanchan Chauhan, head of the Bionanotechnology Department at CNyN, noted that tumours consist of various cell types that activate mechanisms to survive medication. This phenomenon contributes to the persistence of the disease or its recurrence. To tackle this issue, the scientists propose combining different therapies within a single nanoparticle to more effectively combat cancer.
“If cancer cells are attacked with a single strategy, they survive through another. Therefore, we aim to combine treatments to mitigate recurrence and treatment resistance,” clarified Chauhan. In this line of research, specialists are also investigating the efficient transport of prodrugs—medications frequently used in chemotherapy that require metabolic transformation to become active within the body. This conversion relies on a specific family of enzymes, which are present in low concentrations in tumour regions but much higher in the liver. Consequently, much of the prodrug is metabolised in the liver before reaching the cancer-affected area, reducing the amount of medication that can act directly on the tumour.
To overcome this challenge, UNAM scientists propose developing nanovehicles designed to transport therapies that aggregate the biocatalysts responsible for activating the prodrug. “By coating the nanovehicles with molecules that act as conductors, we can deliver the payload to the tumour site, ensuring the prodrug is optimally transformed in that area. This way, we hope to reduce doses and minimise adverse effects on normal tissues,” added Chauhan. Initial laboratory tests have shown promising results, with the dosage of certain medications potentially reduced to one-sixth of the original quantity, while tumour size decreased by 50%.
Simultaneous Diagnosis and Treatment Innovations
These findings have encouraged the team to explore photodynamic therapy, which involves incorporating a dye, carbon quantum dots, or photosensitive molecules into the nanovehicle, capable of triggering reactions that damage cancer cells when exposed to specific wavelengths of light. Additionally, these photosensitive substances possess fluorescent properties that allow for observation under microscopy, enabling tracking of the nanovehicles within cells. In the future, researchers believe these characteristics could facilitate new alternatives for identifying diseased cells, imaging tissues, and conducting simultaneous diagnostic and treatment procedures.
The development of these nanovehicles for such applications is still in the experimental phase. To date, all tests have been conducted in vitro, meaning outside a living organism, although the team is preparing to initiate trials using animal models. While further research is necessary to establish their efficacy and safety in subsequent stages, the modified nanoparticles have already been granted two national patents and one international. Nevertheless, it remains imperative to verify that the results are reproducible, that the devices can be manufactured at scale, and that they can be safely transported and distributed to hospitals.
Although it may take years before this technology is widely utilised in humans, Rubén Cadena asserts that the aim of this work is to reduce costs and provide new tools for developing accessible diagnostic tests. “It is crucial to contribute to solving problems in our country and improving people’s quality of life, even if it takes time, as numerous regulations must be adhered to for a project of this nature to reach pharmacies,” he concluded.