Pigskin is made into corneas to restore vision for the blind without waiting for donations.

usepigskinThe cornea can restore the vision of visually impaired patients.

really？ ? ?

Yes, this study was recently published in Nature Biotechnology, a sub-journal of Nature, and a pilot study has been carried out, which has restored the vision of 20 patients without adverse reactions.

In the world, there are as many as 12.7 million people who are sick or even blind because of corneal damage. At present, the most common method is to transplant corneas donated by human beings, but only one in every 70 patients can get a corneal transplant.

Moreover, patients who need corneal transplantation often gather in low-income and middle-income countries or regions, and the opportunities for treatment are very limited.

At this time, the pig came, and the pig came with its powerful effect.

However, when it comes to pigskin, few people associate it with cornea. How are they related?

Using collagen molecules from pigskin

One of the main components of cornea is collagen. By extracting collagen molecules from pigskin, researchers developed a collagen-based corneal matrix substitute: Bioengineered Porcine Construction (Double Crosslinked for short: BPCDX).

How exactly is it done?

Firstly, after extracting collagen from pigskin, it was purified and freeze-dried.

Collagen was then dissolved in sterile phosphate buffered saline (PBS) at room temperature to form a 5% collagen solution.

Next, a new vacuum evaporation technology is used, which can controllably achieve high collagen content (12-18%). In the past, the weight of collagen in human test implants was limited to 10% (the natural human corneal collagen content was 13.6%).

However, pure collagen is a soft material which is easy to degrade. In order to solve this problem, researchers used two chemical crosslinks to finally form a transparent implantable hydrogel, which improved the mechanical strength, degradation resistance and long-term stability of the implant.

But is it reliable to use pigskin to make cornea and treat visually impaired patients?

In this regard, the researchers also conducted a series of clinical trials, and they conducted feasibility studies in India and Iran.

The researchers implanted BPCDX in 20 visually impaired patients to reshape the native corneal stroma without removing existing tissues or using sutures.

During the two-year follow-up, no adverse phenomena were observed.

As can be seen from the table, 14 legally blind people before operation were not judged to be blind after operation. Moreover, all subjects in the two queues were intolerant of contact lenses before operation, but they could tolerate wearing contact lenses for a long time at 24 months after operation.

Judging from the effect of clinical trial, this is not an unreliable technology, but it sounds very complicated. Can ordinary patients afford it?

Low cost, easy storage and minimally invasive.

Mehrdad Rafat, an associate professor of biomedical engineering, said:

We do a lot of research to ensure that this technology is affordable for everyone, not just the rich.

In this technology, pigskin used in extracting collagen is a by-product of food industry, which is easy to obtain and the cost is not very high.

In addition, researchers have developed compatible packaging and sterilization processes, so that bioengineered corneas can be stored for up to two years before use, so that they can be provided to different regions and even rural areas without biological banks or storage tissue preparation facilities.

It is worth mentioning that the cornea made of pigskin does not need to remove the patient’s own tissue when treating visually impaired patients, but instead, it is a small incision through which the implant is inserted into the existing cornea.

And this new surgical method does not need suture, but uses advanced laser surgery to make corneal incision with high precision, and then uses simple surgical instruments to perform it manually when necessary.

It costs less and is minimally invasive, so when will this technology be popularized?

Not yet!

Before using implants in medical care, it is necessary to conduct larger-scale clinical research and obtain market approval from regulatory agencies.

In addition, researchers also want to study whether this technology can be used to treat more eye diseases, and whether implants can be adapted to individuals to obtain greater curative effects.

One More Thing

In fact, in 2016, there was a successful case of bioengineered corneal transplantation in South China. A 14-year-old boy from Jiangxi chose bioengineered membrane transplantation. After a week of treatment, his vision reached 0.1.

However, this operation uses a rarer pig cornea, and this study of Nature is to extract collagen from pig skin to make a corneal substitute. In contrast, the latter has greater application potential.