New Chemistry Research Could Make Drug Delivery Easier and Safer
Novel methods in an emerging chemistry field could have game-changing implications for cancer treatment and monitoring, thanks to emerging research from the QUT Centre for Materials Science.
Dr Nathan Boase is spear-heading new research in bioorthogonal photochemistry: light-stimulated chemical reactions that happen inside the body without interfering with or interference from other reactions.
The new chemical methods could lead to improved drug delivery, better disease identification and monitoring, and safer patient outcomes across a spectrum of health issues.
Future of healthcare
Current treatment methods for diseases like cancer often involve patients receiving drugs that can interact with a multitude of biological systems, wreaking havoc on the body and causing disruptive side effects.
“Bioorthogonal chemistry offers an alternative that can deliver results in a much more targeted way,” Boase said.
“Targeting highly specific areas of the body for chemical reactions means, for example, that a cancer treatment could be fine-tuned to only interact with tumour cells, reducing side effects and increasing patient wellbeing.”
The research could allow medical professionals to tag and track particular biomolecules — like disease biomarkers — within the body to show disease progression and evolution.
“We can create chemistries that detect specific molecules that are implicated in a disease — for example, if there’s increased production of hydrogen peroxide within certain cancers,” said Boase.
“We can then design that chemistry to only respond to those increased levels, meaning that it won’t interact with normal biological processes or systems without the disease present.”
The highly selective nature of bioorthogonal chemistry has big implications for drug delivery, too — including reduced or even eliminated side effects.
“A non-targeted drug could impact a lot of other systems in the body as it’s metabolised,” said Boase.
“But a bioorthogonal chemical reaction could be so targeted and selective that it could start or stop without disrupting anything else in the body’s pathways.
“For example, we can ensure that the toxic chemical reaction of chemotherapeutics only occurs inside the cancerous tumour.
“This opens up the possibility of increasing dosages of toxic chemotherapy drugs without affecting other parts of the body.
“If it works, we’ll completely revolutionise the design of dynamic materials for medicine.”
Working with the body
Boase’s research focuses on developing new biocompatible polymeric materials to deliver the chemistry to targeted areas in the body, and using molecules as a light source to kick off the chemical reactions.
“In any cell there are millions of reactions going on at any one time as part of a normal metabolism,” Boase said.
“We’re creating chemical tools that allow us to control those processes just a little bit.
“We’re trying to create synthetic reactions that are distinct from what occurs naturally in the body — that way it can’t interfere with or be disrupted by native biochemical reactions.
“The bioorthogonal chemistry will probe what’s actually happening in the body, in combination with medical imaging, while specially crafted polymers will direct the chemistry to targeted areas of the body and protect the chemistry along the way.”
For example, a polymer could be designed with chemistry that would respond to a certain cellular stimulus, like an increase in hydrogen peroxide from cancer cells.
The polymer would be injected into the body carrying an imaging agent, which the polymer would protect until it found tissue with higher levels of hydrogen peroxide.
It would then release the imaging agent, switching on a signal that could be detected by medical imaging, allowing for these tissues with higher hydrogen peroxide — which are potentially cancerous — to be visualised directly.
“It means that we can locate, see and understand chemical imbalances and what’s causing them without invasive procedures,” said Boase.
“This type of chemistry gives us the tools to better understand what’s happening within the body, and to work in synergy within the complexity of the human body.”
Shine on
Boase’s research will use light as the energy source to trigger the bioorthogonal chemical reactions within the body, which will give greater control over the chemistry.
Photostimulation is often achieved by taking a light source from outside of the body and projecting it inwards — like a torch on an endoscope or a laser.
However, light from the outside body can only penetrate about 1 cm into the skin, which limits its application.
Boase wants to investigate injecting molecules into the body to act as internal light sources.
Success will come when Boase’s polymers, carrying the bioorthogonal chemistry, meet the light-emitting molecules at just the right place and time.
“We aim to design the polymer and the light source to work synergistically to create the highly specific chemical reactions.
“The diseased tissue will be detected and imaged using medical imaging, and the polymer will then carry the bioorthogonal chemistry to the diseased tissue through molecular targeting.
“Only when both elements are present will the chemical reaction take place.”
Boase’s research is in the early stages but shows a lot of promise for future development — identifying this gap in the research was just the beginning.
“We’re excited to find out if this will all actually work the way we think it will — if we can actually design a functioning system to create more advanced methods of probing biochemistry in the human body,” Boase said.
More information
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