Case Study and Goal of FIsh Skin Application

In Brazil, there was a case study of Tilapia Fish skin being used as an alternative treatment for burn wound treatments. Traditionally, human skin graft implantation is the ideal solution for burn wound treatments. However, in Brazil, there was a lack of available transplants in skin banks. Instead, the less effective treatment method was to use silver sulfadiazine cream and bandages which are more painful and expensive to apply daily. Therefore, Brazil plastic surgeons had the idea of using Tilapia fish skin which is a cheap byproduct of the fish-farming industry, which is high in type 2 collagen (helpful for accelerating wound healing). They even tested their sterilize prototype bandage successfully on burn victims with 3rd degree burn wounds. In another instance, this Tilapia skin bandages were used on wild animals facing forest burn wounds in America. They were also more ideal than bandages as they are do not require multiple reapplications, and will not obstruct the animal’s digestive tracts if swallowed.

Currently, the main goal of this fish skin exploration was to create a more affordable and simple method of fish skin sterilization technique, alongside the integration of antimicrobial agent such as Aloe vera gel. Currently, animal-based medical products are still not legally transportable across countries, that is why simpler sterilization techniques can allow for more accessible usage of this fish skin technology.

Modified Fish Skin Sterilization Technique

During the investigation to figure out the different patented sterilization techniques of used to treat the fish skin, it was realized how highly complicated and costly it would require to be used in a medical grade purposes. Therefore, it was sought out to attempt modifying the fish skin sterilization methodology by first testing out only one type of sterilization agent/medium and monitor the state of the fish skin in a concealed setting (sealed in airtight plastic film). The following preliminary trials involved solutions of Ethanol 99.5%, 1M NaOH, 1 M NaCl, and Control upon two species of Tilapia (Nila and Mujair). Based on the preliminary trials it was qualitatively found that the NaCl condition was most beneficial for producing a desirable flexibility and consistency throughout the duration, with NaOH coming up second, but being more fragile due to the breakdown of structural tissue from the highly basic environment. However, it is clear that NaOH is simply not enough to solely sterilize fish skin. Contrastingly, the ethanol condition suffered more drastic changes by day 4 where dehydration of the fish skin occurred quite quickly, and some of the Nila fish skin showed yellow-colored fungal growth. Furthermore, the control treatment group also dried up quite quickly (due to being frozen prior) and has no sterilization techniques applied on it yet.

Continuing with the preliminary results, the sterilization continued to combine several different compounds to sterilize a different kind of fish skin (Rainbow Trout). First, after the frozen fish skin is rehydrated with the 1 M NaOH for a few hours in a refrigerated state. Then, the fish skin dipped in 1 M NaOH is used to deproteinize the excess flesh attached to the skin/fat layer. However, this process can also be completed more effectively with directly pulling the fish skin off the flesh manually (not slicing), since highly alkaline conditions thin out the skin layer (more fragile). Next, malachite green powder was added with concentration of 0.1 g/L of water in order to act as a powerful anti-fungal agent. Following that, the fish skin was rinsed in 96% ethanol concentration to kill bacteria and remove excess malachite green/NaOH stuck on skin (lowered concentration to avoid dehydration of fish skin). Lastly, the fish skin was rinsed in distilled water before being combined with the additional antimicrobial Aloe vera gel, vacuum sealed, then frozen for further usage.

Interesting Discovery

An additional discovery found during the investigation, was the formation of a jelly-like polymer when fish skin was let to dip into a solution of 1 M NaCl for several days while in a refrigerated state. Additionally, this polymer sometimes could revert back into a viscous liquid if let in room temperature long enough, or let to re-solidify in refrigerated state. It can be hypothesized that the following mixture is composed of the collagen either type 1 or 2 found in the fish’s skin.