Cancer is one of the leading world killers, with a higher percentage of cases being diagnosed than ever before. This increase in rate of diagnosis is due to medical improvements, parallel to this needs to be medical improvements for methods to treat cancer patients. The most common and best known method for cancer treatment is chemotherapy, where anti-cancer drugs are administered to the patient in a toxic dose with the aim to kill cancerous cells. However there are side effects due to the toxic dose required in order to cause cell death. One method to overcome this is the use of prodrugs, these are drugs which are not in an active form when administered to the patient and are activated when in the body. Directed enzyme prodrug therapy involves the use of enzymes to activate these prodrugs, these enzymes are attached to a delivery system for direction towards the target site when in the body, where they are intended to activate the prodrug, inducing cell death.
Nanoparticles are considered by many to be the future of science and technology, and already have their place within some aspects of medicine, with the most common being medical imaging. It has already been shown that certain types of enzymes can be genetically manipulated to conjugate to gold nanoparticles, the incorporation of a gold nanoparticle with a superparamagnetic core such as Fe3O4 would allow for these enzymes to be directed through the body to a target site. However once reaching the target site the biggest challenge remains, and that is trying to introduce a foreign body into a cell, which usually have mechanisms in place to prevent this or destroy foreign objects that are able to enter the cell. Cell penetrating peptides, commonly referred to as CPPs, offer a way to deliver various objects into cells leaving the cargo intact to allow for medical cargo delivery.
This project outlines a novel synthesis method for coating Fe3O4 nanoparticles with gold, the purification, characterization and stability of these nanoparticles in various mediums. The nanoparticles produced have an average size of 50 nm, and are stable in a range of mediums. Following this a genetically modified enzyme has been successfully conjugated onto this nanoparticle and tested for its ability to cause cell death in cancer cells, and compared with nanoparticle:enzyme:CPP conjugates. The results from these trials show that the conjugate without the cell penetrating peptide is able to cause cell death, however the level of cell death is increased when a CPP is used, indicating a successful improvement in cellular uptake.