212: Chapter 212 Autologous Cell Membrane

On the third day that Chen Youhua had locked himself in his office, Wang Zhe pushed the door open and entered.

"You're not dead yet?" Wang Zhe tossed a bag of steamed buns onto the desk. "The cafeteria is about to close, so I brought these for you."

Chen Youhua poked his head out from behind the computer screen, his eyes bloodshot and his hair a mess.

He glanced at the buns and then at Wang Zhe. "Why are you here?"

"To see if you're still alive." Wang Zhe pulled up a chair and sat down. "Li Wei asked me to come; she said you hadn't spoken in the group chat for three days and was afraid something had happened to you."

"What could possibly happen to me?"

"The last time you didn't speak for three days, you were proving the Navier-Stokes Equation. The time before that, you were working on enlightenment. What about this time? What big news are you working on now?"

Chen Youhua didn't answer, instead picking up a bun and taking a bite.

It was cold, but still edible.

"brain-computer interface," he said indistinctly.

Wang Zhe froze for a moment. "What?"

"brain-computer interface." Chen Youhua swallowed the bun. "Placing electrodes into the brain to directly read Neural Signals. People with High-level Paraplegia, ALS, or those who can't even speak could use their thoughts to control computers, wheelchairs, and prosthetics."

Wang Zhe fell silent for a while.

He was a biology student and knew exactly what that meant.

"You're doing this alone?" he asked.

"I'll start on my own. I'll come find you guys when I hit a wall."

Wang Zhe wanted to say something but stopped himself, looking at the items on the desk instead.

A pile of printed papers, several open books, a half-eaten piece of bread, and a cup of tea brewed who-knows-when; the tea leaves had settled at the bottom, and the water was cold.

"You've been living on this for three days?" Wang Zhe pointed at the bread.

"And instant noodles."

Wang Zhe sighed, stood up, and walked to the door. He glanced back. "I'll bring you food tomorrow. Don't die."

The door closed. The office became quiet once again.

Chen Youhua finished the bun and went back to reading papers.

He was reading an article about Flexible Electrodes. A foreign laboratory had spent three whole years creating a bendable Electrode Array that could be placed on the surface of the brain without needing to be inserted.

The downside was poor signal quality; it could only read general brain region activity and couldn't pick up signals from individual Neurons.

"enlightenment," he said, "what do you think of this approach?"

"The signal resolution is too low to achieve fine control," enlightenment's voice came from the computer. "If it's just for controlling a simple switch, like turning lights on and off, it's barely enough. But to control a prosthetic, it's far from sufficient."

"What if we make the electrodes smaller?"

"Theoretically possible. But the smaller they are, the harder they are to manufacture and the easier they break. Furthermore, even if they are made smaller, they are still on the surface of the brain. The signal has to pass through the Meninges, Cerebrospinal Fluid, and Cortical Tissue, resulting in too much attenuation."

"So we still have to use an invasive approach."

"Yes."

Chen Youhua rubbed his temples.

Invasive means trauma, immune response, scar tissue, and signal attenuation.

This is exactly where brain-computer interface research worldwide is stuck.

The deeper the electrode is inserted, the better the signal, but the faster it fails. The shallower it is placed, the safer it is, but the worse the signal.

"enlightenment, is there a material that the Immune System won't attack after it's inserted?"

"Yes. The human body's own cells."

"What if we coat the outside of the electrode with a layer of human cells?"

"Theoretically feasible. However, cells are living things that require nutrients, specific temperatures, and a culture medium. Inside the brain, they wouldn't survive more than a few days."

"What if we strip off the cell membrane? Just leave a layer of membrane to wrap around the outside."

enlightenment was silent for two seconds.

"Father, this idea... is very new. The Proteins and Glycoproteins on the surface of the cell membrane are the key signals for the Immune System to recognize 'one of its own.'"

If we only keep the membrane structure and remove the internal active substances, we could theoretically deceive the Immune System into thinking the electrode is part of its own body."

"Can it be done?"

"Theoretically, yes. But it would require extracting the volunteer's own cells, culturing, lysing, extracting the cell membrane, and then wrapping it around the electrode surface. Every step is difficult."

Chen Youhua stood up and walked to the whiteboard. It was already covered in writing.

Materials, electrodes, signals, encoding, immunity.

He drew a line under "Immunity" and wrote "Autologous Cell Membrane Coating."

"Let's do this first," he said.

"Understood, Father. However, I suggest you sleep first. You have only slept four hours a day for three consecutive days."

Chen Youhua glanced out the window; it was already dark. He was indeed a bit sleepy.

"Alright. We'll talk tomorrow."

He turned off the computer and walked out of the office. The corridor was very quiet, with only the green light of the emergency exit flashing.

He walked downstairs. The campus streetlights were on, and a few students were playing basketball, the sound of the ball hitting the ground echoing with a thud.

He stood by the roadside and watched for a moment.

A student missed a shot, and the ball rolled to his feet.

"Hey man, help us throw it back!" the student shouted.

Chen Youhua bent down to pick up the ball and threw it back.

The ball traced an arc through the air and landed steadily in the student's hands.

"Thanks!"

He waved his hand and continued walking.

...

The next day, he went to see Teacher Zhou from the Medical School.

Teacher Zhou specialized in cell culture. He was in his fifties, with graying hair and a slow manner of speaking.

Chen Youhua had briefly explained his purpose over the phone, and Teacher Zhou told him to come over directly.

"Professor Chen," Teacher Zhou led him into the Cell Room, "I think I understand the plan you mentioned. Extracting Autologous Cell Membranes to wrap around the electrode surface. It's a great idea, but there are several issues."

"Go ahead."

"First, the extraction and purification of the cell membrane. After cell lysis, the membrane will break into small fragments; how do you wrap these fragments completely around the electrode surface?"

"Second, the uniformity of the coating. If some areas are covered and others aren't, the Immune System will still attack the exposed parts."

"Third, long-term stability. Cell membranes are composed of Proteins and lipids, which will degrade in the body. How long can it last? Three months? Six months? A year?"

Chen Youhua nodded. He had considered these problems, but not in such detail.

"For the first problem, we can use a Microfluidic Chip," he said. "By passing the electrode through a microchannel containing cell membrane fragments and using fluid mechanics to control it, we can have the fragments adsorb uniformly onto the electrode surface."

Teacher Zhou thought for a moment. "Feasible. But it would require tuning the parameters."

"For the second issue, we can use multi-layer wrapping. If one layer isn't enough, we'll use two; if two aren't enough, then three."

"That would increase the thickness of the electrode."

"That's acceptable, as long as it doesn't affect the implantation."

Teacher Zhou glanced at him. "You've thought this through quite carefully."

"I've been thinking about it for a long time."

Teacher Zhou smiled. "Alright. Then what about the third problem? Long-term stability."

"I don't know," Chen Youhua said honestly.

"But I don't think it needs to last too long. It just needs to last through the window period for nerve growth. Once the nerves have grown, a stable connection between the electrode and the nerves will have formed. Even if the outer cell membrane degrades, the Immune System won't necessarily attack, because the nerves will have already accepted the electrode as part of themselves."

Teacher Zhou was silent for a moment.

"This idea is a bit risky," he said, "but it's not entirely without merit."

"Then, are you willing to help me?"

Teacher Zhou smiled. "Of course, after all, you are Professor Chen. Let's go then."