Professor Pieter Cullis received his Ph.D. from the University of British Columbia and continued his research career there in lipid biochemistry.
Prof. Cullis is a pioneer in lipid nanoparticles, which have been used
for various applications in medicine such as delivering anticancer drugs to cancer tissues without causing too much toxicity in normal tissues. The most remarkable type of lipid nanoparticles developed by Prof. Cullis is lipid nanoparticles with ionizable cationic lipid. These lipid nanoparticles have no charge at neutral pH, but become positively charged in low pH. Because of the absence of positive charge, the lipid nanoparticles are not toxic to cells. When they are taken up by cells into endosomes, the acidic pH in endosome turns the neutral lipid into positively charged lipid, which causes fusion to negatively charged cellular membrane. This membrane fusion delivers the content of the lipid nanoparticles into cytoplasm of the cells. This technique has been successfully employed to develop the delivery system of mRNA vaccines, which are being used to control the COVID-19 pandemic.
The achievement of Prof. Cullis not only made COVID-19 mRNA vaccines possible but has also created a way to safely deliver nucleic acid into cells,
which opened up possibilities for various applications of nucleic acid technology
for prevention and treatment of many diseases in the future.