In third-degree burn treatment, hydrogel helps grow new, scar-free skin

In early testing, this hydrogel, developed by Johns Hopkins researchers, helped improve healing in third-degree burns. Credit: Will Kirk/JHU

Johns Hopkins researchers have developed a jelly-like material and wound treatment method that, in early experiments on skin damaged by severe burns, appeared to regenerate healthy, scar-free tissue.

In the Dec. 12-16 online Early Edition of Proceedings of the National Academy of Sciences, the researchers reported their promising results from mouse tissue tests. The new treatment has not yet been tested on human patients. But the researchers say the procedure, which promotes the formation of new and , including hair follicles, could lead to greatly improved healing for injured soldiers, home fire victims and other people with third-degree burns.

The treatment involved a simple wound dressing that included a specially designed hydrogel -- a water-based, three-dimensional framework of polymers. This material was developed by researchers at Johns Hopkins' Whiting School of Engineering, working with clinicians at the Johns Hopkins Bayview Medical Center Burn Center and the Department of Pathology at the university's School of Medicine.

Third-degree burns typically destroy the top layers of skin down to the muscle. They require complex medical care and leave behind ugly scarring. But in the journal article, the Johns Hopkins team reported that their hydrogel method yielded better results. "This treatment promoted the development of new blood vessels and the regeneration of complex layers of skin, including hair follicles and the glands that produce skin oil," said Sharon Gerecht, an assistant professor of chemical and biomolecular engineering who was principal investigator on the study.

Gerecht said the hydrogel could form the basis of an inexpensive burn wound treatment that works better than currently available clinical therapies, adding that it would be easy to manufacture on a large scale. Gerecht suggested that because the hydrogel contains no drugs or biological components to make it work, the Food and Drug Administration would most likely to classify it as a device. Further animal testing is planned before trials on human patients begin. But Gerecht said, "It could be approved for clinical use after just a few years of testing."

Guoming Sun, left, a postdoctoral fellow, and Sharon Gerecht, an assistant professor of chemical and biomolecular engineering, helped develop a hydrogel that improved burn healing in early experiments. Credit: Will Kirk/JHU

John Harmon, a professor of surgery at the Johns Hopkins School of Medicine and director of surgical research at Bayview, described the mouse study results as "absolutely remarkable. We got complete skin regeneration, which never happens in typical burn wound treatment."

If the treatment succeeds in human patients, it could address a serious form of injury. Harmon, a coauthor of the PNAS journal article, pointed out that 100,000 third-degree burns are treated every year in U. S. burn centers like Bayview's. A burn wound dressing using the new hydrogel could have enormous potential for use in applications beyond common burns, including treatment of diabetic patients with foot ulcers, Harmon said.

Guoming Sun, a Maryland Stem Cell Research Postdoctoral Fellow in Gerecht's lab and lead author on the paper, has been working with these hydrogels for the past three years, developing ways to improve the growth of blood vessels, a process called angiogenesis. "Our goal was to induce the growth of functional new blood vessels within the hydrogel to treat wounds and ischemic disease, which reduces blood flow to organs like the heart," Sun said. "These tests on burn injuries just proved its potential."

Gerecht says the hydrogel is constructed in such a way that it allows tissue regeneration and blood vessel formation to occur very quickly. "Inflammatory cells are able to easily penetrate and degrade the hydrogel, enabling blood vessels to fill in and support wound healing and the growth of new tissue," she said. For burns, the faster this process occurs, Gerecht added, the less there is a chance for scarring.

Originally, her team intended to load the gel with stem cells and infuse it with growth factors to trigger and direct the tissue development. Instead, they tested the gel alone. "We were surprised to see such complete regeneration in the absence of any added biological signals," Gerecht said.

Sun added, "Complete skin regeneration is desired for various wound injuries. With further fine-tuning of these kinds of biomaterial frameworks, we may restore normal skin structures for other injuries such as skin ulcers."

Gerecht and Harmon say they don't fully understand how the hydrogel dressing is working. After it is applied, the tissue progresses through the various stages of wound repair, Gerecht said. After 21 days, the gel has been harmlessly absorbed, and the tissue continues to return to the appearance of normal skin.

The hydrogel is mainly made of water with dissolved dextran, a polysaccharide (sugar molecule chains). "It also could be that the physical structure of the hydrogel guides the repair," Gerecht said. Harmon speculates that the may recruit circulating bone marrow stem cells in the bloodstream. Stem cells are special cells that can grow into practically any sort of tissue if provided with the right chemical cue. "It's possible the gel is somehow signaling the stem cells to become new skin and blood vessels," Harmon said.

More information: Sharon Gerecht's Lab: www.jhu.edu/chembe/gerecht/

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that_guy
not rated yet Dec 13, 2011
But the researchers say the procedure, which promotes the formation of new blood vessels and skin, including hair follicles,


So, the potential implications and possibilities go far beyond burn victims, albeit in a somewhat greusome way.

Consider a bald guy going in to get surgically scalped, and then having a full mop of hair growing back.

Or, more realistically, think about the old ladies in hollywood getting ultra deep face peels, and then this gel helps regenerate new skin. They'll have the sking of a teenager.

I think that the real procedures may probably be less extreme than my imagination, but consider the possibilities.
Pirouette
1.5 / 5 (8) Dec 13, 2011
To be honest, I have some reservations about this stuff. From the article, I'd say that they're saying that the hydrogel acts as a matrix for the natural skin, blood vessels, etc. to grow INTO it through absorption of the hydrogel. BUT, what if the hydrogel doesn't really just get absorbed, but REPLACES the skin itself after being absorbed, or melds its molecules with skin to create a new kind of bio-material. It's not like they took skin from another part of the mouse and applied it to the burnt area to grow new natural skin as is done now in burn units.
Also, what is the freshness date for the dextran? Will it attract bacteria that might grow on it?
"The hydrogel is mainly made of water with dissolved dextran, a polysaccharide (sugar molecule chains). "It also could be that the physical structure of the hydrogel guides the repair," Gerecht said." Then they say later on that they're not sure how it works.
I hope it does help to grow new skin on human burn victims, but the jury is out.
RETT
not rated yet Dec 13, 2011
I know that Occam's Razor isn't a law, but when it is followed, it usually has useful results. This is so simple that it should be usable in the most primitive of conditions. Think of this as a possible universal wound treatment, including surgical incisions. The polysaccharide follows an old remedy that found major use in the Civil War and before, where sugar poultices were used on wounds. Since they had nothing else, it saved many lives. In modern settings, such poultices are in reasonably common use to treat skin ulcerations on extremities where other treatments have failed. I suggested such to a man who had Hansen's many years ago, and still suffered from terrible ulcerations on his feet due to lack of pain sensitivity. The poultices healed what the doctors could not. They had strongly suggested amputation When he died almost a decade later, he still had both feet. The major advantage to this is the ability to use it in field situations. Try to grow germs on a sugar base..you can't
RETT
not rated yet Dec 13, 2011
I know that Occam's Razor isn't a law, but when it is followed, it usually has useful results. This is so simple that it should be usable in the most primitive of conditions. Think of this as a possible universal wound treatment, including surgical incisions. The polysaccharide follows an old remedy that found major use in the Civil War and before, where sugar poultices were used on wounds. Since they had nothing else, it saved many lives. In modern settings, such poultices are in reasonably common use to treat skin ulcerations on extremities where other treatments have failed. I suggested such to a man who had Hansen's many years ago, and still suffered from terrible ulcerations on his feet due to lack of pain sensitivity. The poultices healed what the docs could not. They had strongly suggested amputation. When he died almost a decade later, he still had both feet. The major advantage to this is the ability to use it in field situations. Try to grow germs on a sugar base..you can't.
that_guy
not rated yet Dec 13, 2011
@pirouette - The body naturally recycles through it's cells on a regular basis, especially skin cells. It also naturally absorbes and expels foreign matter.

The body will naturally use, break down, or otherwise process a sugar chain.

It is not a completely inert substance.

Also, it gel that consists of elements that replace skin will have different properties from skin. I'm sure that they can account for that.

@Rett - Another scenario is that it is possible that in lab conditions, the skin reverts to a more primitive type of state (like a stem cell). It is certainly possible that in the real world with hormones and stress - a whole body and so on that you may not get desired results.

Isaacsname
5 / 5 (1) Dec 13, 2011
I wonder if I could grow myself some brain on it.
Pirouette
2.3 / 5 (9) Dec 13, 2011
@that_guy. . .thanks for the info. . .but since it hasn't as yet been tested on humans. . .several trials will be needed anyway to make sure it's truly safe.
Yes, I had read somewhere awhile back about sugar being poured on a wound when a hospital emergency room was not available and the wound healed well. I had forgotten that sugar, as well as salt are natural preservatives. . .but nobody puts salt on a wound, so that's out. :)
Pirouette
2 / 5 (8) Dec 13, 2011
I wonder if I could grow myself some brain on it.


What's wrong with the one you have? Only one to a customer. :)
I read your opinions on the V shapes. Very interesting.
Sean_W
3 / 5 (2) Dec 13, 2011
I wonder if old wounds and scars could be treated using an anesthetic, a finely calibrated laser to remove the scar layer and a gell like this.
Nanobanano
3 / 5 (4) Dec 13, 2011
RETT:

I had heard from a nurse that they used to use Sugar and Iodine on people in nursing homes for the bed sores or other ulcerations that people got.

Maybe this is the beginning of true nano-tech medicine...
Pirouette
1.7 / 5 (6) Dec 13, 2011
I understand that turning the patient from side to side often usually helps to avoid bedsores. But also keeping the skin clean and free from sweat is also necessary. The hydrogel might also be good for ulcerations, we hope. Usually, these nursing homes don't have enough nurses and other personnel to turn the patients often like they should because it's not considered emergency care as in a burn unit. But a lot of the elderly are neglected. One would hope that doesn't happen to oneself.
Almost time to go outdoors to see the Geminids meteor shower.
Deesky
5 / 5 (1) Dec 13, 2011
This is pretty awesome and simple, if it can work in humans. I suspect that it should as there isn't anything too 'tricky' in the treatment. Had they used some kind of stem-cells, then perhaps there might have been potential problems, but since it uses the body's own healing mechanisms, I reckon it has a high chance of success.

Consider a bald guy going in to get surgically scalped, and then having a full mop of hair growing back.

I'm not sure that that would be the case. My take is that the gel uses your own body's infrastructure to regenerate what is damaged, so if you were suffering from male pattern baldness, then it's likely that the same state would be restored. But I'm sure though that they'll give it a go anyway (as it would mean big bucks).
Pirouette
1.6 / 5 (7) Dec 13, 2011
We all want to look good, obviously. But I'm thinking of a patient with facial burns. I'm wondering if they will have hydrogel patches that conform to the nose, cheeks, ears, etc. . . .all the various unique angles of the face and neck. For esthetic reasons, I would imagine.
jimbo92107
5 / 5 (2) Dec 14, 2011
This might also be a way to regenerate good skin that needed to be removed for some other medical reason.
Isaacsname
5 / 5 (2) Dec 14, 2011
@Pirouette, I'm sure it could be molded to have specific shapes, it's just a variation on the polymer that's in disposable diapers :O
rubberman
3 / 5 (2) Dec 14, 2011
Remarkably simple. If this is as effective on humans as it is on the lab rats, I can't wait to see it in action.
Pirouette
1.6 / 5 (7) Dec 14, 2011
Remarkably simple. If this is as effective on humans as it is on the lab rats, I can't wait to see it in action.


Yes. . .burn victims would get a new psychological lease on life.

@Nano. . . .I'm giving you a FIVE score. . .you know who is still giving me ONES in every thread. LOL
Pirouette
1.6 / 5 (7) Dec 14, 2011
@Pirouette, I'm sure it could be molded to have specific shapes, it's just a variation on the polymer that's in disposable diapers :O


@Isaacsname. . . .what polymer would that be?
Pirouette
1.7 / 5 (6) Dec 14, 2011
The above article explains the chemistry of the hydrogel as a combination of water and dextran, a polysaccharide.
Googling the chemistry of polymers in disposable diapers, I find this: "Superabsorbent polymers are prepared from acrylic acid and a crosslinker by solution or suspension polymerization. The type and quantity of crosslinker control both the swelling capacity and gel modulus.2 The synthesis and use of crosslinked polyacrylate superabsorbents have been a popular topic in the polymer literature. However, very little information about manufacturing processes has been given due to its proprietary content."
The crosslinker component(s) is not explained.
By "variation", I assume you mean that one is made from sugar and water, while the other is made from a polyacrylic acid. One polymer being organic, while the other is made from OIL = plastic. Unfortunately, I skipped most of my Applied Chemistry classes in high school. Not a big loss.
TheGhostofOtto1923
1 / 5 (8) Dec 14, 2011
BUT, what if the hydrogel doesn't really just get absorbed, but REPLACES the skin itself after being absorbed, or melds its molecules with skin to create a new kind of bio-material.
OOh sounds dangerous... Perhaps the lost wax process would work better in replacing skin -? Yes thats right, just like at Tussauds-
Pirouette
2.3 / 5 (9) Dec 14, 2011
@Ghost. . .still talking out of your asshole, I see.
Pirouette
2 / 5 (8) Dec 14, 2011
For anybody who is interested. . .in another thread, I gave my theory as to the reason for some V shapes on the floor of a building in Israel from 2800 years ago.

Here's the link if you would care to see what a jerk Ghost, a hemorrhoid in the ass of FH, is.

http://www.physor...lem.html
Pirouette
2 / 5 (8) Dec 14, 2011
well, this WAS a nice thread, and now he has ruined it. I suppose he and FrankH or one of their aliases will follow me into another thread. LOL
TheGhostofOtto1923
1.4 / 5 (10) Dec 15, 2011
Sorry P you keep posting nonsense and drivel and you will be insulted for it. This is how we adults do things is it not? You can't be afraid of 'new biomaterial' because you have no idea what that means. You think the doctors and scientists don't know far more than you do about how to develop this material safely and avoid problems?

I know - you can't avoid posting inanity because your brain contains little else. This is evident in your many empty posts and your posturing manner. But feedback from myself and others should only help to make you aware of this, and hopefully you will consider thinking through your opinions and RESEARCHING them before you expose them to critics like myself. Who after all enjoy making fun of such carelessness. Consider it constructive ridicule.
Isaacsname
4.3 / 5 (3) Dec 16, 2011
Well Piro, I never even went to the classes because I dropped out before I even started them, never even finished 9th grade.

I am teaching myself about these things in my spare time, nothing more, nothing less.

The major difference between the polymers, that I can understand, is that this one will break down quite easily, the primary problem with cross-linked polymers is that they are incredibly stable,iow, it takes years for them to be broken down in the environment.
Pirouette
2 / 5 (8) Dec 17, 2011
@Isaacs. . . .I am learning also, just as you are. I don't trust "polymers" made from plastics that are applied to skin or internally until they have been perfected and tested exhaustively. They might have no ill effects whatsoever, but we don't know that, except for the ones that have been in use for many, many years already and are on the market. And no, I don't pretend that I know much more than the researchers. But even researchers have been known to fail, as pharmaceuticals, for instance, have been pulled off the market because of some dangerous effects. I would let years go by and let thousands of users try it first before i let myself or my family use such products. Although the sugar and water seems to be alright
FrankHerbert
1.9 / 5 (18) Dec 17, 2011
Pirouette has no idea what "polymer" means. He thinks it's synonymous with plastic which I'm assuming to him gives it an unnatural and therefore bad connotation.

Both polymers and plastics are such broad categories that to claim one might be dangerous as a result of fitting into one or both categories shows quite a bit of ignorance. It's like saying "Nah doc, I don't want the laughing gas. I heard they used poison gasses in the World Wars. Not for me."

If only he knew how many polymers his skin encounters on regular basis...

But he's always right about everything and if you disagree you're a socialist/communist bent on destroying America.
Pirouette
2.2 / 5 (10) Dec 18, 2011
Phewwww!! Looks like FrankHerbert is back again to stink up the thread with his brainfarts. A lot of people won't talk to him and he resents that. LOL
Pirouette
2.3 / 5 (9) Dec 18, 2011
""The major difference between the polymers, that I can understand, is that this one will break down quite easily, the primary problem with cross-linked polymers is that they are incredibly stable,iow, it takes years for them to be broken down in the environment.""
@Isaacs. . . .that's just my point. . .plastics degrade very slowly. . .not at all like something organic.
FrankHerbert
1.4 / 5 (14) Dec 18, 2011
@Isaacs. . . .that's just my point. . .plastics degrade very slowly. . .not at all like something organic.


This is just my point. You understand very little of the terminology you use. There are organic compounds that survive millennia and plastics that degrade in weeks. There are also plastics composed of organic compounds.
TheGhostofOtto1923
2.1 / 5 (11) Dec 18, 2011
And no, I don't pretend that I know much more than the researchers.
-An inkling of what you dont know:
. . .plastics degrade very slowly. . .
-Except for the ones that do you dimwit.
not at all like something organic.


"Organic (Chemistry) of, relating to, or belonging to the class of chemical compounds that are formed from carbon"

-This includes most plastics you dimwit.

"The vast majority of plastics are composed of polymers of carbon and hydrogen alone or with oxygen, nitrogen, chlorine or sulfur in the backbone."

-This makes them organic you dimwit.

Isnt there a place on perez hiltons website where people like you can feel at home posting whatever occurs to you?
Pirouette
2.3 / 5 (9) Dec 18, 2011
@Ghost. . . .you STILL persist in talking out of your asshole. . .therefore, it is YOU that is the dimwit.
Oh yes, I forgot that you and FrankH are sucking each other's dicks and where one goes to verbally assault someone, the other gets his licks in also. I don't care what you know or don't know. You and your boyfriend FrankH have no right trying to prevent other members from adding to the discussion. . . .whether correct or incorrect. Who died and left YOU the boss of Physorg, by the way?
350
2.3 / 5 (6) Dec 18, 2011
children! Fucking stop your bitching at each other!!!
FrankHerbert
1.3 / 5 (13) Dec 19, 2011
@Ghost. . . .you STILL persist in talking out of your asshole. . .therefore, it is YOU that is the dimwit.
Oh yes, I forgot that you and FrankH are sucking each other's dicks and where one goes to verbally assault someone, the other gets his licks in also. I don't care what you know or don't know. You and your boyfriend FrankH have no right trying to prevent other members from adding to the discussion. . . .whether correct or incorrect. Who died and left YOU the boss of Physorg, by the way?


Moderators, please remove the above post. It clearly falls under the "OFFENSIVE" category. Feel free to remove mine for being off topic :)
Noumenon
3.5 / 5 (8) Dec 19, 2011
As does this one;

I, rightly so, called you a "sick piece of shit" over PM. This is the first and only PM I have sent you.

Nah you didn't have any to begin with you sick piece of shit.

Also fuck your family :) - FrankHerbert


www.physorg.com/n...ina.html
TheGhostofOtto1923
1.8 / 5 (10) Dec 19, 2011
@Ghost. . . .you STILL persist in talking out of your asshole. . .therefore, it is YOU that is the dimwit.
Oh yes, I forgot that you and FrankH are sucking each other's dicks and blahblahblah
But why would you insist on exposing your appalling lack of even basic scientific knowledge to ridicule? Why? Do you crave ridicule?

Frank and myself are not the only ones who show you how you simply lack the basic knowledge to participate here. Many people have shown you this.

The only reason you persist must be because you enjoy being humiliated. Thats pretty sad.

Why dont you try somewhere else where you might feel more comfortable? Does sesame street have a blog? Maybe a nice organic gardening website?
Pirouette
2.5 / 5 (8) Dec 20, 2011
@Ghost. . . .you STILL persist in talking out of your asshole. . .therefore, it is YOU that is the dimwit.
Oh yes, I forgot that you and FrankH are sucking each other's dicks and blahblahblah
But why would you insist on exposing your appalling lack of even basic scientific knowledge to ridicule? Why? Do you crave ridicule?

Frank and myself are not the only ones who show you how you simply lack the basic knowledge to participate here. Many people have shown you this.

The only reason you persist must be because you enjoy being humiliated. Thats pretty sad.

Why dont you try somewhere else where you might feel more comfortable? Does sesame street have a blog? Maybe a nice organic gardening website?


It appears that TheGhostofOtto1923 and FrankHerbert have taken it upon themselves to be the sergeants-at-arms or the schoolyard bullies of Physorg where they base their vicious attack dog decisions on who goes and who gets to stay by a member's performance.
Pirouette
2.5 / 5 (8) Dec 20, 2011
Apparently, Ghost and FrankHerbert are of the opinion that nobody has the right to come into a thread to voice their opinions and also learn something new from those who are more knowledgeable, like barakn, noumenon, ethelred and bluehigh and that a member has to get past the schoolyard bullies, Ghost and FrankHerbertfart, before a member can enter the "classroom".
I shudder to think how University students, on becoming Physorg members, would be treated by these 2 bullies due to the young students' lack of the right terminology and exact scientific knowledge that would be required before they are accepted to ask questions and posit their own theories. There is something very insane about these two whose sole purpose seems to be the "guardians at the gates" or in the role of "bouncers" to prevent anyone remaining at the dance hall who fall short of their expectations. As with Oliver, they cannot live and let live, or even ignore what is said by others. Their attempt at ridicule is sad.
FrankHerbert
1.3 / 5 (15) Dec 20, 2011
Moderators, the above two posts should be removed for being "OFF TOPIC" and are an abuse of the forum. Thank you. Feel free to remove mine as well.
Noumenon
3.7 / 5 (9) Dec 20, 2011
Yes, indeed, Moderators please do. Oh, and while you're at it, please ban members who a) Arbitrarily rate other members 1's no matter the content of those posts, and b) maintain multiple screen names to rate themselves 5's while rating others indiscriminately 1's. Obviously, this beng as much an abuse of the posting guidelines as above.

*this would mean banning FrankHerbert.

Pirouette
2.7 / 5 (7) Dec 22, 2011
Nou. . .Perhaps he needs some hydrogel for his mental scars. . .oh wait. . .there's no cure for that kind.
Pirouette2
2.1 / 5 (7) Dec 22, 2011
Frankherbert$hit wishes they would cure his hatred. . .No wonder he sleeps alone!
FrankHerbert
1 / 5 (15) Dec 22, 2011
LOL Pirouette, did you forget to log out of your puppet account before posting again? HAHA

So the Vietnam vet wants to talk about mental scars. Can you sleep without a fan on? How about a gun under the bed?

How long were you addicted to smack? Do you still relapse?

Do you have nightmares with Jane Fonda in them?

:P
Noumenon
4 / 5 (8) Dec 22, 2011
Nou. . .Perhaps he needs some hydrogel for his mental scars. . .oh wait. . .there's no cure for that kind.


There is a photo of Frank at the top right of this web page.
that_guy
5 / 5 (2) Dec 22, 2011
Wowowowow you guys. Frank is closer to the facts than many of you. Let's go ahead and all of you draw some circles for a venn diagram.

In Circle 1, label it polymers. Some polymers are organic, some are not. Most polymers are plastic, a few are not. Polymers are any kind of compound that can easily be linked into repeating chains and achieve very high molecular weight.

In circle 2, label it plastics. Some plastics are polymers, some are not. Some are organic, others are not. Plastics can be toxic or nontoxic. Plastics are substances that shaped or formed, and then hardened - The definition of plastic is actually ambiguous, because it can include substances not considered to be plastic. It is a somewhat relative definition, and mostly colloqually used to refer to organic plastics.

Organic just means it contains carbon. Since carbon is so awesome at bonding in many ways, it is convenient to use.

Continued...
that_guy
5 / 5 (2) Dec 22, 2011
So most of what we refer to as 'plastics' are both polymers and organic. just because it's made from cellulose or oil or silicon doesn't change that. It can be toxic or nontoxic.

These various terms are such wide nets, that to use them to describe more than the one discrete property defined by the definition is pointless and stupid.

We use polymer plastics for implants in the body. We use non-plastic polymers in space travel. We use non polymer plastics as well.

This is the absolute dumbest semantic conversation I have ever run across.
that_guy
5 / 5 (2) Dec 22, 2011
So most of what we refer to as 'plastics' are both polymers and organic. just because it's made from cellulose or oil or silicon doesn't change that. It can be toxic or nontoxic.

Correction, "just because it's made from cellulose or oil doesn't change that. But it can be made from silicon or other substances as well."
Pirouette
2.5 / 5 (6) Dec 23, 2011
@that_guy. . .thanks for the informative explanation. . .I think I have a handle on it now. :)
RETT
5 / 5 (2) Dec 25, 2011
Pirouette, your body is full of polymers of one sort or another, and every dressing except the pure cotton ones is a polymer of one sort or another. For the rest of the semantics, something can be "plastic" without being "a plastic", most clay for example. A polymer is just a substance composed of repeating chains of molecules. Cross-linked polymers are merely chains of molecules that are linked together by molecular bonds at some point other than at their ends. Neither plants nor animals nor almost any living thing would exist without polymers in general, and polysaccharides in particular. A little knowledge is a dangerous thing, but try reading the wiki segments on polysaccharides and dextrans. I suspect from that, that the dextrans used for the hydrogel are of high molecular weight to prevent rapid metabolization. Distrust of all polymers means that you distrust yourself, which, in this case, would be wise.