Hydrogels are materials that are commonly used in everyday objects such as contact lenses to control humidity. However, chemical engineers at the University of Guadalajara (UdeG) in Mexico have developed a new technology based on thermosensitive nanoparticles (nano-hydrogels) to use these materials in the field of biomedicine to achieve the controlled release of anticancer drugs.
Professor Eduardo Mendizábal Mijares from the university's Department of Chemistry said: 'We used nano-hydrogels loaded with drugs and injected them into the patient. Because of their physical and chemical properties, which make them biocompatible, they're not detected by the body's immune system while passing through the bloodstream.'
The idea is that the drug, within the nano-hydrogel, is transported directly to the cancer cells where it is released without damaging other parts of the body. Able to dose a wide variety of active substances using a number of different routes (oral, nasal, buccal, rectal, transdermal, vaginal, ocular and parenteral), drug release can be initiated by a volume increase or a change in pH or temperature.
Magnetic particles can also be added to hydrogel nanopolymer to produce a 'force field' that raises the temperature, when necessary, to destroy the cancer cells.
The research, focused on developing thermosensitive nano-hydrogels which, through a polymerisation technique, mixes substances with different chemical and physical characteristics to achieve a chemical reaction and form a set of small spheres called polymers.
The nano-hydrogels have shown good biocompatibility characteristics owing to their physical properties, making them resemble living tissues, especially in terms of high water content, soft and elastic consistency and low interfacial tension, which prevents the absorption of proteins.
By developing these materials, it has been possible to absorb large amounts of water without losing shape, as well as retain heat at a temperature of 37–42°C. 'By combining emulsion polymerisation and microemulsion technology, we were able to synthesise structured hydrogels that have better mechanical properties than conventional hydrogels,' said the researcher.
These materials are used primarily in the biomedical area as diagnostic tools in membranes, coatings, microcapsules and implants for controlled drug release, as well as for tissue regeneration, fracture treatment and as substrate for cell growth.
Although molecular targeting drugs are already used against cancer, the novelty of the work is that materials such as nano-hydrogels can attack cancer cells or tissues without damaging healthy body parts.
