Delivering life-saving drugs directly to the brain in a safe and effective way is a challenge for medical providers. One key reason: the blood-brain barrier, which protects the brain from tissue-specific drug delivery. Methods such as an injection or a pill aren’t as precise or immediate as doctors might prefer, and ensuring delivery right to the brain often requires invasive, risky techniques.
A team of engineers from Washington University in St. Louis has developed a new nano-particle generation-delivery method that could someday vastly improve drug delivery to the brain, making it as simple as a sniff.
“This would be a nano-particle nasal spray, and the delivery system could allow medicine to reach the brain within 30 minutes to one hour,” said Ramesh Raliya, research scientist at the School of Engineering & Applied Science.
“The blood-brain barrier protects the brain from foreign substances in the blood that may injure the brain,” Raliya said. “ But when we need to deliver something there, getting through that barrier is difficult and invasive. Our non-invasive technique can deliver drugs via nano-particles, so there’s less risk and better response times.”
The novel approach is based on aerosol science and engineering principles that allow the generation of mono-disperse nano-particles, which can deposit on upper regions of the nasal cavity via spread. The nano-particles were tagged with markers, allowing the researchers to track their movement.
Next, researchers exposed locusts’ antenna to the aerosol, and observed the nano-particles travel from the antennas up through the olfactory nerve, which is used to sense the smell. Due to their tiny size, the nano-particles passed through the brain-blood barrier, reaching the brain and spreading all over it in a matter of minutes.
The team tested the concept in locusts because the blood-brain barriers in the insects and humans have similarities. “The shortest and possibly the easiest path to the brain is through your nose,” said Barani Raman, associate professor of biomedical engineering. “Your nose, the olfactory bulb and then olfactory cortex: two steps and you’ve reached the cortex.”
To determine whether or not the foreign nano-particles disrupted normal brain function, Saha examined the physiology response of olfactory neurons in the locusts before and after the nano-particle delivery and found no noticeable change in the electro-physiological responses was detected.
This is only a beginning of a set of studies that can be performed to make nano-particle-based drug delivery approaches more principled, Raman said. The next phase of research involves fusing the gold nano-particles with various medicines, and using ultrasound to target a more precise dose to specific areas of the brain, which would be especially beneficial in brain-tumor cases.
【小题1】What is the passage mainly about?| A．A novel method of drug delivery. | B．A challenge facing medical staff. |
| C．A new medicine treating brain disease. | D．A technique to improve doctor’s ability. |
| A．Doctors prefer using methods like an injection to treat diseases. |
| B．Locusts were tagged with markers to track their movement. |
| C．The blood-brain barrier lowers the effectiveness of a pill. |
| D．The medicine could reach the brain within half an hour. |
| A．human and locusts have similar structures that protect brain from foreign substances |
| B．the delivery process consists of the olfactory bulb and the olfactory cortex |
| C．locusts have changeable electrophysiological responses to nanoparticles |
| D．the shortest and possibly the safest path to the brain is through human’s noses |
