"Is this a bioartificial kidney?"
Wei Kang stretched out his left hand wearing a rubber glove, picked up a pear-sized cylinder, put it in his hand and looked at it carefully.
The shell of this thing seems to be a layer of flexible metal, exuding a soft silvery white luster. You can feel a slight coolness in the palm of your hand through the rubber, but there is no hard feeling.
The top is firmly connected to a thick rubber tube, and the two outlets at the end are also connected to tubes, but they are two smaller tubes, one large and one small.
"Yes, this is an artificial kidney that can replace the function of the kidneys, purify the blood, and excrete metabolic waste in the blood into urine."
Ding Mian stood nearby, a faint glow appeared on his face, which was the light of confidence, and he talked eloquently.
"Kidney transplantation has always been the only solution to cure end-stage renal disease, and the shortage of kidney sources has always been very serious."
“With the development of medical technology, kidney transplantation has progressed from human-human homogeneous transplantation to clinical-level pig-human xenogeneic kidney transplantation.”
"Although the effect is not bad, the world's first pig-human kidney transplant patient successfully produced urine 20 minutes after the operation. The transplanted pig kidney also survived in the body for 74 hours without acute rejection."
"The patient later died due to massive bleeding, but in any case, it opened the door to xenotransplantation."
"Of course, such a solution also has a lot of hidden dangers, and the mid- and long-term rejection reactions cannot be predicted."
"Therefore, scientists turned their attention to artificial kidneys without giving up."
"The hemodialysis machine can alleviate the uremia crisis and replace the function of the kidney, but it also has many inconveniences such as high price, infection, coagulation, painful needle insertion, and poor convenience. If the artificial kidney is successfully developed, these problems will definitely be solved."
"Speaking of artificial kidneys, we must first understand the basic functions of the kidneys."
"The human kidney has 2 million glomeruli and tubular cells, which bear the heavy responsibility of metabolism. The former filters the blood, intercepts specific molecules, and forms a screening function. The latter has a reabsorption function and can absorb water and electrolytes again to form the final Urine.”
"Our artificial kidney simulates the functions of glomeruli and renal tubules, achieving the same effect as a kidney."
"The tubes on it are connected to the arteries. Arterial blood flows into the artificial kidney. It first passes through the 'blood filter', which is the artificial glomerulus. There is a specially designed porous nanofiltration membrane inside that allows specific molecules to pass. Intercept everything else."
"The filtered blood continues to pass through the bioreactor. There are cultured living renal tubular cells on the silicone membrane inside, as well as some other components, which can simulate the 'reabsorption' function of the renal tubules."
"Finally, the two lower tubes are thicker and connect to the veins to transport healthy blood back, while the other thinner tube is connected to the bladder and excretes urine filled with metabolic waste."
"This entire set of equipment can completely replace the function of the kidneys."
“The biggest highlight of it is that the filtration mechanism completely imitates the working mode of the human kidney, so it is very efficient. An artificial kidney of this size can produce about 800 ml of urine in 24 hours. This efficiency is very close to that of a real kidney. of kidneys.”
"The artificial kidney in your hand can receive 300 ml of blood input per minute, 90% of which will be filtered out by the blood filter, forming 30 ml of original urine. Finally, after being filtered by the reabsorption function, only 0.6 ml becomes urine. about."
"Of course, this artificial kidney is currently built for animal experiments, so it is made smaller. If it is to be implanted into the human body, it will be made larger to better meet the needs of the human body."
"This kind of efficiency is much higher than the current main treatment method for uremia - hemodialysis, and it is also much more convenient."
"If patients undergo dialysis every day, they have to stay next to the dialysis machine for several hours. Plus the waiting time in line, there is not much time left at the end of the day. This greatly restricts personal freedom and makes it impossible to do many things, even work. Had to give up.”
"As long as our artificial kidney is implanted into the body, it can replace the kidney and allow patients to return to normal life. They don't even need a urine bag."
Ding Mian finished this long paragraph in one breath and showed a proud smile.
Wei Kang smiled and said: "Well done, how did you think of doing this thing in the first place? I remember that the artificial kidney project has not been approved. So you did it secretly?"
Ding Mian's expression changed and he said quickly: "Speaking of which, it was a complete accident when we did the artificial kidney."
"It's actually a bonus of the artificial bladder project."
"When making an artificial bladder, I made a simulated urinary system because blood is filtered to produce urine. However, I have never been able to solve the problem of reabsorption, resulting in incomplete filtration of urine and blood residue in it."
"Later, we used stem cells to culture a batch of renal tubular cells, and added some materials to enhance the absorption function, so we solved this problem."
"I was so excited after I finished it. I didn't even think about approving the project first. I just found a dog and made a finished product and put it in."
"The experiment was successful. After one of the dog's kidneys was removed, the artificial kidney in the dog's body still functioned as a kidney, and there was no decrease in urinary function."
"This means the emergence of a universal implantable bioartificial kidney that can self-regulate water and salt balance without a blood pump, and has already achieved results in animal models."
Having said this, Ding Mian scratched his hair and said with a naive smile.
"Haha, it was only then that we realized that we had actually made an artificial kidney by mistake."
Wei Kang looked surprised and couldn't help but praise.
"I didn't expect that the artificial bladder project could also hatch an artificial kidney. It was really unintentional."
"You are really great. There are scientists like you in Sanqing. I feel deeply proud."
He looked at the artificial kidney in his hand and suddenly realized that something was missing.
"Does this device only have three tubes? Is there no other external connections? Is there no power cord or anything?"
Ding Mian smiled and shook his head: "No, it is the perfect crystallization of physics and chemistry. It is full of simple beauty and has nothing superfluous."
Wei Kang was confused: "You just said that there are only blood filters and bioreactors in it, so where is the power source? What drives the entire device? Electric energy? Bioenergy? Or something else?"
Ding Mian waved his hand and explained with a smile.
"We use the normal blood pressure difference in the human body as the power source for blood flow filtration, which eliminates the need to use a blood pump, greatly reduces the volume, and does not require additional energy, so it can be implanted into the human body and work in the body for a long time."
Wei Kang nodded and glanced at Xue Shen, who was silent next to him, and couldn't help but feel relieved.
"I'm really excited for you two to join forces on a new project."
"The filter membrane used in this artificial kidney and the use of blood pressure differences as a power source are all physical functions. It is probably Xue Shen's work."
Ding Mian nodded repeatedly and praised his friends generously.
"That's right, it's all thanks to Brother Xue that this project can go so smoothly."
"Brother Xue has developed a nanometer-scale silicon pore membrane, which is very similar to glomerular cells. It can prevent large molecules from passing through and allow small molecules to pass through."
"There is also a silica gel membrane in the bioreactor, which helps the renal tubular cells maintain their activity and plays a key role."
"In addition, he also gave a lot of optimization suggestions from a physical perspective for a lot of data used during the experiment, which was of great help."
Wei Kang was about to nod when he suddenly remembered another question and asked.
"I know that human kidney cells are permanent cells with extremely strong compensatory capabilities. They can repair themselves when damaged. However, if they are completely damaged, they cannot be restored. This also leads to the occurrence of uremia."
"As for this bioreactor, the main components of the bioreactor inside are renal tubular cells, which sounds good, but they are all artificially cultured cells, and their compensatory capacity is definitely not as good as real kidney cells, so isn't it? Will he die?"
"What happens if these cells harden and die after a certain period of time?"
"So does it need to be replaced regularly? Or what?"
"If it is replaced regularly, its application prospects may be limited, and it cannot be considered a true implantable bioartificial kidney."
When Ding Mian heard this series of questions, the smile on his face suddenly disappeared, and his head froze like an eggplant beaten by frost.
He let out a long sigh and whispered: "Mr. Wei, we do have this problem. Although we can extend the survival period of renal tubular cells, after all, if they are placed in a closed device, their biological activity is really limited."
"And if it is used at high intensity, the cells themselves will not be able to compensate and repair."
"It will definitely become deactivated over time, but the specific time is difficult to estimate and depends on usage."
"We have done tests and found that after at least six months, the renal tubular cells will begin to undergo hyalinization and will be unable to complete their intended functions."
"In this case, the bioreactor can only be used if it is replaced."
"In addition, there is also the issue of equipment maintenance. Over time, not only the renal tubular cells will have problems, but even the silicon porous membranes can easily cause blood clots during the hemodialysis process, leading to a decline in filtration function."
"Although artificial kidneys have been developed and animal experiments have been successful, these two problems do exist."
"Long-term experiments are needed in the future to observe adverse reactions and long-term prognosis after implantation."
Wei Kang smiled and said, "It doesn't matter. Now that we have discovered the problem, we have a direction to work towards. I believe that one day in the future, you will be able to solve this problem."
He looked thoughtful and said thoughtfully.
"Perhaps we can make it a non-implantable artificial kidney. At least it is very light and powerful and can replace most of the kidney functions."
"Patients can hang it on their body like a urine bag, so that they can urinate every day, instead of holding it in for two days before going for dialysis. You must know that for severe patients, if they hold it in for a few more hours, accidents may easily occur. "
“This thing might be able to free patients from dialysis machines and allow them to live a normal life and have a semblance of dignity again.”
Ding Mian's eyes lit up and he blurted out: "Mr. Wei, you are right, I just thought about getting there in one step."
"This artificial kidney may not be able to completely solve patients' problems now, but at least it can gradually improve their lives."
"You have to eat your food one bite at a time, and you have to walk the road step by step. Think about solving the problem first, and then think of ways to solve the problem more beautifully."
"But don't worry, I will continue to work hard with Brother Xue to see if the artificial kidney can be made into a finished implantable product."
Xue Shen also quickly patted his chest to confirm.
"Don't worry, Mr. Health. As for the project, it will definitely be a phased achievement. Step by step, we will first make the non-implantable artificial kidney, and then we will tackle the implantable artificial kidney."
Wei Kang smiled slightly, gently placed the artificial kidney in his hand on the workbench, and looked around in the laboratory.
"Where is the experimental dog with the artificial kidney? Take me to see how it is doing."
"It's in another room. I'll take you there." Ding Mian said quickly.
The three of them came to another room, where an entire wall was covered with densely packed cages containing various experimental animals.
Wei Kang saw the puppies in the bottom row of cages at a glance.
The puppy was lying in the cage. When he saw someone coming in, he immediately stood up, pushed his furry head out hard, and made a purring sound.
Ding Mian said in surprise: "The dog seems to be more energetic today. It seems that he just had surgery a few days ago and is still recovering. Now he has fully recovered."
He was a little worried at first, fearing that the boss would see a sick and weak puppy. Unexpectedly, in just a day or two, the puppy became lively again, and he suddenly felt relieved.
So he continued: "After traditional kidney transplantation, long-term use of immunosuppressants is required, but this dog only took antiplatelet drugs and did not receive immunosuppressive treatment."
"Compared with large animal models of renal failure, the artificial kidney can significantly improve the dog's blood volume and eliminate excess body fluids."
Wei Kang walked over and stroked the dog's head.
The puppy stuck out its tongue and licked his hand. Its big wet eyes looked full of spirituality.
Wei Kang checked the wounds on the puppy and found that they were almost healed, with no obvious marks visible on the outside.
Press lightly and you can feel a little hardness in the waist and abdomen.
But he didn't dare to exert any force for fear of hurting the puppy, so he withdrew his hands after a while.
"Yes, it seems that our first patient is in good condition. Let's continue to observe him."
"If those two problems cannot be solved, I'm afraid we will have to do another surgery to remove the implanted artificial kidney from the dog's body and make it an external artificial kidney."
Wei Kang thought to himself, and suddenly felt a bit of anticipation.
"When it enters clinical practice, patients with end-stage renal disease will be able to completely get rid of dialysis machines and use convenient and efficient artificial kidneys."
"Such a scene, I'm a little excited when I think about it."
(End of chapter)
