The Future of Materials
Elevator Pitch
Hi, my name is Brittney Ketchum and let me tell you about the new and improved surgery screws. Every year about 6 million people break their bones and if you are lucky, you just need a cast and you’ll be A-Okay. On the other hand you might need the extra support of surgery screws. Traditionally titanium screws are used but then you’re stuck with these screws in your body for the rest of time. Thankfully, a group of German scientist have created a new type of screw that react similarly to a gelatin capsule filled with expanding foam. This screw is a combination of polylactic acid and hydroxyapatite. The polylactic acid is similar to the gelatin as it dissolves harmlessly in your body. The hydroxyapatite is like the expanding foam once it is released from its container it expands filling any holes around it. So let me ask you a question would you rather have a metal screw or a gelatin-like screw in your body? With your generous contribution the polylactic hydroxyapatite can become the new standard in surgery screws.
Dissolving Screws While Regrowing Bones
By: Brittney Ketchum
Breaking bones can be such a pain, both literally and figuratively. When you break a bone you end up having a cast that all your classmates want to sign. However, there are instances when a cast on the bone will not suffice and surgery is needed in order to get screws drilled into your bones to help hold them in place while the bones heal.
The screws most commonly used are made off a titanium alloy. These alloys are strong enough to withstand any pressure placed on the bone. However, when the bone has healed, the screws must then be removed through another surgery leaving gaping holes within the wound that must heal over time, or if they aren’t removed, then you’re stuck with the extra metal in your body for the rest of your existence.
Recently, scientists took the idea of dissolvable stitches and applied it to surgery screws. Similar to the dissolvable stitches, these screws would dissolve over a period of time, thus eliminating the need to go back in to have the screws removed.
There are a few concerns to be aware of when thinking about dissolvable devices that are placed deep within the body. First off, it has to be nontoxic. The point of placing screws in your body is to help you heal, so why would we put a device into your body that could potentially harm you?
The second thing is that it has to be strong and can’t dissolve too quickly, if it does, then the bones may not heal properly or actually might break again. Third, though not entirely necessary, it would be beneficial for the implants to be made of materials that do not contain metal to add simplicity. Metal implants can lead to aches and pains on a semi-daily basis or when the weather is cold. Finally, it needs to be compatible with your body so your body doesn’t see it as a threat and start attacking the device.
Acknowledging these difficulties, scientists first tried making dissolvable screws out of magnesium alloys. Since magnesium is naturally found in the body, meaning that the device would be accepted into the body without any difficulties. The problem with the magnesium screws is that they dissolved too quickly to be of use. The bones would then move out of position and finish healing improperly. Also, there were still holes left in the bone where the screws were.
Polymers were also tried which lead to the benefit of not having to worry about having unnecessary metal in the body that would make certain tasks very difficult, nor would it dissolve too quickly in the body like the magnesium alloys. However, when dissolved, the polymer released toxins into the body. Next, they tried a screw made fully of polylactic acid which is safe for the body but still leaves holes in the bone. So scientists continued to try and improve these surgical screws.
The next step towards dissolvable screws was a pure polylactic acid design. The polylactic acid dissolves harmlessly in the body within two years. This design solved the problem of the screws being strong enough while also completely dissolving into the body. However, to create these screws temperatures of 2,500°F must be achieved, which is highly economically taxing.
Then in 2010, German scientists created a screw made of a polylactic acid and hydroxyapatite composite. The polylactic acid dissolved into the body while the hydroxyapatite remained. Hydroxyapatite also known as hydroxylapatite is a porous material that has a chemical composition similar to bone. The hydroxyapatite then actually encourages the bone to grow and fill in the hole where the screw was originally placed in the bone. The temperatures needed to compress this new screw requires nearly 1/10 of the pure polylactic acid screw therefore saving energy along with your bones.
By: Brittney Ketchum
Breaking bones can be such a pain, both literally and figuratively. When you break a bone you end up having a cast that all your classmates want to sign. However, there are instances when a cast on the bone will not suffice and surgery is needed in order to get screws drilled into your bones to help hold them in place while the bones heal.
The screws most commonly used are made off a titanium alloy. These alloys are strong enough to withstand any pressure placed on the bone. However, when the bone has healed, the screws must then be removed through another surgery leaving gaping holes within the wound that must heal over time, or if they aren’t removed, then you’re stuck with the extra metal in your body for the rest of your existence.
Recently, scientists took the idea of dissolvable stitches and applied it to surgery screws. Similar to the dissolvable stitches, these screws would dissolve over a period of time, thus eliminating the need to go back in to have the screws removed.
There are a few concerns to be aware of when thinking about dissolvable devices that are placed deep within the body. First off, it has to be nontoxic. The point of placing screws in your body is to help you heal, so why would we put a device into your body that could potentially harm you?
The second thing is that it has to be strong and can’t dissolve too quickly, if it does, then the bones may not heal properly or actually might break again. Third, though not entirely necessary, it would be beneficial for the implants to be made of materials that do not contain metal to add simplicity. Metal implants can lead to aches and pains on a semi-daily basis or when the weather is cold. Finally, it needs to be compatible with your body so your body doesn’t see it as a threat and start attacking the device.
Acknowledging these difficulties, scientists first tried making dissolvable screws out of magnesium alloys. Since magnesium is naturally found in the body, meaning that the device would be accepted into the body without any difficulties. The problem with the magnesium screws is that they dissolved too quickly to be of use. The bones would then move out of position and finish healing improperly. Also, there were still holes left in the bone where the screws were.
Polymers were also tried which lead to the benefit of not having to worry about having unnecessary metal in the body that would make certain tasks very difficult, nor would it dissolve too quickly in the body like the magnesium alloys. However, when dissolved, the polymer released toxins into the body. Next, they tried a screw made fully of polylactic acid which is safe for the body but still leaves holes in the bone. So scientists continued to try and improve these surgical screws.
The next step towards dissolvable screws was a pure polylactic acid design. The polylactic acid dissolves harmlessly in the body within two years. This design solved the problem of the screws being strong enough while also completely dissolving into the body. However, to create these screws temperatures of 2,500°F must be achieved, which is highly economically taxing.
Then in 2010, German scientists created a screw made of a polylactic acid and hydroxyapatite composite. The polylactic acid dissolved into the body while the hydroxyapatite remained. Hydroxyapatite also known as hydroxylapatite is a porous material that has a chemical composition similar to bone. The hydroxyapatite then actually encourages the bone to grow and fill in the hole where the screw was originally placed in the bone. The temperatures needed to compress this new screw requires nearly 1/10 of the pure polylactic acid screw therefore saving energy along with your bones.
Reflection
The chemistry of materials has improved our present lives, out-shined the past, and will renovate how we see the future. Think back on most any technology that was used before the 1800's, all that technology seems really bland and out-dated doesn't it? Now, we have rubber tires, gas and electric powered transportation, and laptops for writing. We haven't stopped there either. Humans are now thinking of ways to create self healing tires, nanotechnology, and numerous of other things that are meant to better our future. All these improvements rely on the chemistry of materials being used. The chemicals that make up the material must first be improved before the material itself can be improved.
The structure of the material on all the different levels is very important. If you want something to be water proof you have to look at the molecular level to ensure that molecular weaving is tight enough so that the water molecules are unable to get through. The same goes all the levels, if you want it certain aspects for the material you must look at all the different levels to ensure that it will work. Something can look waterproof on the macroscopic level but fail to be waterproof on the atomic level.
The structure of the material on all the different levels is very important. If you want something to be water proof you have to look at the molecular level to ensure that molecular weaving is tight enough so that the water molecules are unable to get through. The same goes all the levels, if you want it certain aspects for the material you must look at all the different levels to ensure that it will work. Something can look waterproof on the macroscopic level but fail to be waterproof on the atomic level.