"Baby, I'm so sleepy."
Xue Shen stood in front of the window, looking far into the distance, then yawned and said.
"You're so sleepy, did you become a thief last night?" A delicate voice came from the phone.
"Yes, I'll steal your heart." Xue Shen said these words with a deep look on his face, causing a burst of laughter from the other side.
Suddenly, two sounds of "cough" sounded at the door, bringing him back to reality from the world of love.
Xue Shen glanced at the door and quickly said to the other end of the phone: "Baby, I'm in a hurry to have a meeting. Let's chat later."
Without waiting for the other party to speak, he hurriedly hung up the phone.
After packing up his turbulent mood, he came to his desk and put on a serious smile.
"Director Chen, you are a distinguished guest. What do you want from me?"
Chen Yiqing looked at him with a smile but not a smile: "I'm sorry to disturb Director Xue."
Seeing Xue Shen's face turn red and his expression become a little shy, he slowly revealed the purpose of his visit.
"Nerve regeneration scaffold? This is a very creative idea."
The two sat down on the sofa. Xue Shen handed over a cup of hot tea and looked thoughtfully through the rising white steam.
But he did not continue, but asked instead.
"I heard that your stem cell therapy is very popular. ALS is a hot topic right now. Why don't you continue to do it? Instead, come here to tinker with this neural scaffold?"
Chen Yiqing smiled lightly: "Actually, stem cell therapy is mainly the result of Ding Mian. I didn't put in much effort, I just used it as a matter of principle. This neural scaffold is my own thing."
Xue Shen nodded approvingly: "As expected of Director Chen, he has his own ideas."
His expression became serious: "According to what you said, the material and structure of this neural scaffold are very important."
"The material must have a certain shaping ability, otherwise it will not be able to form a hollow structure, and it will be difficult to adapt to the complex spinal cord environment to guide the growth of neurons. It must also be soft enough not to damage surrounding uninjured tissues. Cause damage.”
"Taking into account biocompatibility and the decomposability of the material after nerve injury recovery, I personally prefer biomaterial scaffolds."
"The material needs to mimic natural spinal cord tissue so that it can be easily populated with neural stem cells, essentially filling the gap left by the injury."
"A biomimetic hydrogel based on collagen can be considered. It can be injected through a needle in the form of a liquid. When it reaches the body, it immediately condenses into a complex nanofiber network, mimicking the extracellular matrix of the spinal cord, providing mechanical support for the scaffold, and providing neural stem cells with Provide a suitable growing environment.”
"As for the structure, it can simulate the porous structure of spinal cord tissue to better meet the electrical signal conduction requirements of spinal cord nerves."
The more Xue Shen talked, the more excited he became. He took out a tablet computer from his desk drawer, opened the drawing software, held a capacitive pen in his hand, and started drawing on it.
"You see, there are three permutations of highly porous scaffolds."
"The first type is a parallel arrangement structure, where the holes are arranged together in a regular manner, just like the cross-section of a pair of stacked chopsticks."
Chen Yiqing interjected: "The spinal cord nerve tracts have this parallel arrangement structure, but axon regeneration cannot form a network, which is not conducive to nerve electrical signal transmission."
Xue Shen didn't even raise his head, and said while drawing: "Yes, so this is inappropriate."
"The second type is similar to the third type, but the former is a network of irregularly sized pores, which is relatively simple, while the latter is a network of highly regular pores, which is more complex."
Chen Yiqing looked at the graphics on the screen and pondered: "The size of these holes should be larger than that of neural stem cells. Otherwise, it will be difficult for the cells to pass through and they will not be able to provide nutritional molecules for the growth of the cells."
"It seems that a highly regular pore network is better. The pores are larger, allowing more cells to crawl in the pores."
Xue Shen nodded: "The holes of different sizes are indeed a problem. Maybe smaller holes will prevent cells from growing through."
"Anyway, we know the size of nerve cells. I will make a 3D model and simulate it on the computer later."
Chen Yiqing couldn't restrain his excitement: "Then what are you waiting for? Let's do it now, or will you have something to do later?"
Xue Shen opened his mouth as if he wanted to say something, but then closed his mouth silently.
After a long time, he groaned: "It's okay, I'll do it for you now."
It took more than an hour for the two to make a simple 3D model on the computer and conduct preliminary AI simulations.
This is also a fixed process in medical research. It is first simulated on the computer, the results are calculated, and then synthesized in the laboratory for subsequent experiments.
Seeing the words "Simulating..." appearing on the screen, Xue Shen finally breathed a sigh of relief.
He glanced at Chen Yiqing, who was looking at the structural diagram he had drawn, thinking hard.
So I quietly took out my mobile phone that was set to silent, opened it, and suddenly felt a tremor in my heart.
My girlfriend has sent me more than a dozen text messages, all of which are coquettish. Since she didn’t get a reply for a long time, her tone gradually escalated and she went crazy.
He wiped the cold sweat from his forehead, danced with his fingers for a while, and typed out a long paragraph of sweet words in one breath.
Click send and add the last sentence.
"Baby, I'm going into the lab right away. You can't bring your cell phone with you. It's in the cabinet."
Then he resolutely threw the phone directly into the drawer.
Chen Yiqing sat upright, looking at his ears, nose and heart, looking attentive.
In fact, his ears had already been perked up, and his eyes flicked out of the corner of his eye, taking in all of Xue Shen's actions.
He couldn't help but snicker in his heart, sighing secretly, "Young people's love is just so sticky and sticky between you and me." However, the expression on his face remained calm and calm.
Xue Shen picked up the cup and drank a large cup of cold tea. When he looked up at the screen, he jumped up.
"The simulation results are out."
When Chen Yiqing heard this, he immediately looked over.
In front of the screen, two thick-haired heads were pressed together, silent for a long time.
After a long time, Chen Yiqing nodded heavily and let out an exclamation.
"Sure enough, nerve cells grew more rapidly in bioscaffolds containing larger pores."
"Although the average pore size and chemical composition were identical in both materials, greater regenerative nerve infiltration was found in the scaffolds with regular pore shapes."
"The latter can greatly improve cell infiltration, gene delivery, nerve electrical signal transmission, and tissue repair after spinal cord injury."
Xue Shen laughed and rubbed his hands excitedly.
"I thought it was right, let's get started in the laboratory!"
"Wait, the basic structure is there, but how do you make it?" Chen Yiqing asked puzzledly.
"Of course it's biological 3D printing. Why don't you know about it?"
Chen Yiqing shook his head: "I've heard of it, but it's large-scale 3D printing, architectural printing, and various models. How can micro structures also be 3D printed?"
"Of course, the traditional biological tissue 3D printing method is really not good at constructing complex 3D microstructures, so I built a new machine and developed a new micro-scale continuous projection printing method."
"Wow, so awesome?" Chen Yiqing listened to this long list of lofty nouns and showed an unclear expression, but at the same time he felt faintly excited.
"Let's go, let's take you to have a good experience."
Xue Shen patted his chest and led an excited Chen Yiqing into the laboratory.
"This is a micron-level 3D printer that can print objects with features as small as 1.5 microns, which is only one-fifth the size of red blood cells."
"Several times smaller than commercial 3D printers, it retains the high printing speed of commercial printers and is more than 100 times faster than other advanced high-resolution 3D printing methods suitable for micro-machining."
Xue Shen pointed to a strange-looking machine on the operating table and introduced it eloquently.
This is an extremely simple-looking metal device. The structure is clear at a glance. The size is much smaller than Chen Yiqing imagined. It looks more like a boxy metal shelf.
Four one-meter-high thick pipes are placed vertically on a metal plate. The pipes are divided into four layers. A large plastic box is placed at the upper and lower ends. The upper one is painted khaki, and the lower one is painted a layer of khaki. Painted gray, the two colors clearly distinguish the boxes.
There are several thick pipes connected to the box at the bottom, painted in various fluorescent greens, and I don't know what they are used for.
There is a black tube on the second floor, connected to a laptop through a red wire.
Chen Yiqing stared blankly at the simple and crude equipment in front of him, speechless for a moment.
Some high-end technology bubbles in my mind were instantly shattered.
If Xue Shen hadn't been so convincing, he would have thought that the interns used discarded materials from the laboratory to practice their skills and built such a strange machine.
It's really too outrageous.
Shoddy workmanship is not enough to describe this piece of equipment. It is cleaner than garbage, and it is the kind of equipment that cannot even be sold as scrap.
He stood in front of the machine, his face changing, and in his heart there were ten thousand grass and mud horses galloping past.
Xue Shen didn't notice at all. He just ran a few operations on the equipment and started running the machine.
After a while, the machine roared and buzzed, giving Chen Yiqing a deeper impression of shoddy workmanship.
Xue Shen came to the machine, stood side by side with him, and excitedly explained the work process.
"It is based on a digital light processing engine and uses adaptive optics technology, which can be used to enhance the image difference of optical devices such as lenses."
"It was developed primarily to meet the growing needs of submicron manufacturing. The Nano Lab already has some rapid prototyping needs for customized submicron parts that require parts that are not restricted by geometric or organic shapes."
"So, we can only develop such a machine ourselves."
"Of course, it's not all my fault. Wang Dali also contributed a lot."
"He is researching that surgical robot and is almost finished. He has also applied some optical technologies to it."
"I have ready-made collagen hydrogel here. I just made a model. I have the materials and drawings. Let's print a model first."
Chen Yiqing listened blankly without saying a word.
"Of course, there must be no neural stem cells in it now..."
Suddenly, the machine made three high-pitched beeps and then stopped.
Chen Yiqing sighed and said with some regret: "It still broke down after all."
But Xue Shen picked up something from the metal plate with excitement on his face and started shouting.
"Haha, in 2 seconds, a 3D bionic hydrogel scaffold suitable for the size of the rodent spinal cord was printed."
He stretched out his palm and carefully handed it to Chen Yiqing.
"Come and admire the 2mm neural scaffold."
"Ah?" Chen Yiqing was stunned.
What the hell, a neural scaffold was printed out in 2 seconds?
It took him a full 5 seconds to come back to his senses and look intently at Xue Shen's palm.
"Your sister, I really let you do it."
His eyes scanned for a while, just like looking for traces of Sun Monkey on the palm of Tathagata Buddha.
After finally finding the 2mm small piece of gelatin, he couldn't help but utter a curse word.
Because this small tic-tac-shaped fragment is really similar to the cross-section of the spinal cord.
Chen Yiqing stretched out two fingers, gently pinched the nerve stent, and looked at it carefully.
He could indeed see some hole structures in the transparent gel, which he was quite satisfied with.
Even now, the inside is hollow and not filled with neural stem cells, so it is not considered a neural scaffold, it can only be called a glial spinal cord scaffold.
He looked at it again and again, observing it for a full minute before reluctantly letting it go.
"Such a thing, if it is inserted into the spinal cord rupture, it might actually work." He turned his head and looked at this simple machine, hesitating to speak.
"This machine of yours seems a bit too rough."
"Did you just take a few pipes and make your own? At least find a serious manufacturer to polish them."
Xue Shen didn't take it seriously and casually said: "It's okay, as long as it works, why bother with so much."
"As for machines, rough Chinese style is the real mechanical aesthetics."
Chen Yiqing took a deep breath and suddenly had nothing to say.
Although he has some obsessive-compulsive disorder to pursue perfection, this machine is a bit annoying no matter how you look at it.
But thinking that Xue Shen was right, he looked away and asked another question.
"Can the accuracy be guaranteed? If stem cells are to be implanted, how should they be used?"
Xue Shen waved and called him over.
"Haha, this is not a problem. Come here and I will show you the 3D model of the machine. You will understand after you take a look."
"But I still need to study the model. Now that the hydrogel is available, it's still unclear what its performance and structure are without experiments."
"Let's try it on rats first."
"I remember that your laboratory has a high-precision MRI, right? I don't have one here. It seems that animal experiments have to be done at your place."
These words made Chen Yiqing excited.
"I think it will work. I also have some opinions on this, and we can discuss it together."
At the moment, the two of them discussed the specific experimental plan in detail.
