Basu began working with associate professor Julia S. Kimbell of the University of North Carolina Chapel Hill Medical School's Department of Otolaryngology as a postdoctoral researcher in April 2016. He has continued that collaboration since coming to SDSU in January 2019.
“Topical sprays are the first line of treatment to reduce sinus inflammation. Surgery is used only when medications no longer work,” Basu said. The new protocol may help more patients get relief without resorting to sinus surgery, thereby reducing health care costs.
To determine how to get the steroid spray to the affected sinus cavities, the research team used CT scans from chronic sinusitis patients to build 3D-printed models. Basu then computationally integrated the 3D models into ANSYS software and simulated drug transport and inhaled airflow.
“One of the challenges is the intricate structure of the nasal passages,” said Basu. To overcome this challenge, he divided the nasal passages into 12 segments. Then he incorporated data on the aerosol droplet sizes, which ranged from five to 25 microns, as well the force with which the spray bottle is activated into the computational model.
“Smaller drops penetrate further into the air space,” he said. “To get larger droplets to hit the target, we need to orient the spray bottle correctly.”
CFD-guided nasal spray usage defined by the Line of Sight protocol was found to significantly enhance topical drug delivery at targeted sinonasal sites, when compared to currently used spray administration techniques.
To validate Basu’s computational modeling experimentally, the researchers added radioactive particles to the spray to track where the droplets were deposited within the flexible 3D-printed nasal models. To replicate the spray nozzle’s angle and depth of insertion into the nasal passages, the researchers used a specially designed positioning device.
In addition, a vacuum line attached to a flow valve mimicked airflow based on breathing data. “The airflow in the sinuses of these patients who were in need of sinus surgery is often compromised by their conditions,” he noted. This rigorous experimental testing confirmed the accuracy of Basu’s predictive model.
Dr. Basu is the lead author on an article describing the aerosol modeling results in the June 2020 issue of Scientific Reports.
The next step will be to recruit patients for clinical trials. To do this, Basu and the UNC researchers are applying for further NIH funding to collaborate with medical schools at Duke University and the University of Wisconsin.