Team:Shenzhen SFLS/Description

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Inspiration & Description

Inspiration

Most of our inspiration comes from real life. In October 2018, one of our team members got injured during the sports activity. He treated the wound with a conventional band-aid and went to bath. However, he soon discovered that the band-aid is not waterproof and caused inflammation of the wound. The terrible experience gives him the inspiration of making a band-aid that is waterproof and bio-compatible. This wonderful idea was shared by him during team brainstorm and soon get accepted by us as the topic of our project.

Description

The focus of our team’s project is producing a more comprehensive and convenient kind of band-aid via biological means in our project. Existing problems in today’s band-aids include 1) they are not waterproof, which means that it is easy for the wound to get in contact with water during showers, swimming, and so on, leading to wound infection; and 2) they may cause contact dermatitis and allergies. After extensive research, we found a protein called MFP (Mussel Foot Protein) gains viscidity in water[1]. More significantly, this protein also has high bio-compatibility and can promote the healing process and cell adhesion of the wounds [2], including its biodegradability making it a perfect protein for our project.

Mussel adhesive proteins can strongly adhere to surface of various materials under wet conditions, such as glass, plastic, metal, wood, and even polytetrafluoroethylene. Moreover, they can effectively bind to biological tissues or organs, and as a result are applied in dentistry, dermatology, orthopaedics and ophthalmology without noticeable toxicity and immunogenicity (Wu et al., 2014;Waite, 2002[3]).

Mussel byssus can be divided into proximal thread and distal plate, which secretes 6 types of proteins(Mfp-1, Mfp-2, Mfp-3, Mfp-4, Mfp-5, Mfp-6). (Rego et al.,2016). These MAPs are rich in dihydroxyphenylalanine (DOPA) that can be catalysed by polyphenol oxidase, which is central to the cross-linking reactions of cohesive curing and adhesive surface bonding (Silverman and Roberto, 2007[3]). Recent studies show that among the 6 types of proteins, Mfp-5 has the highest DOPA content, which is approximately 30% (Waite, 2011[3].) Hence it directly plays a major role in adhesion. (Waite, 2011[3])

As it has exhibited so many superior properties, there has been extensive researches on the applications of this protein. First of all, due to its fantastic bio-compatibility, the protein is applied as ingredient of bio-coatings. For example, Yoo Seong Choi and some co-authors published a research that uses recombinant of mfp5 protein to produce bio-coating and bulk adhesive [4].

Fig1: The plasmid and plaque of recombinant mfp5 (sourced from passage [4])

Other scholars attempted to make the material into hydrogel [5] to promote wound healing, as Rui Wang and co-authors discovered “hydrous physiological environments and the high level of moisture in hydrogels severely hamper binding to the target tissue and easily cause wound infection, thereby limiting the effectiveness in wound care management.” [5] However, a mussel adhesive protein created a path for them to solve the problem. They make “the Dopa-rich protein (mfp-5) acts as the adhesive primer”[5] and modify the protein further with Dopa. This combination solves the problem of aqueous related infections and promote wound healing.

Fig 2 The molecular structure and actual view of hydrogel (sourced from passage [5])

Also, many research focus on the design of self-assemble adhesive material. In 2014, professor Zhong and co-authors researched on the properties of fused protein containing mfp. [1] His team express the mfp3 protein and perform protein fusion to link the csgA protein, who forms complex entangling structures with the mfp, thereby strongly promotes the self-assembling properties of the resultant protein.

Fig 3: The structure of multiple fused proteins. (sourced from passage [1])

However, mussel foot protein has a low yield rate. It is easy to solidify and difficult to purify. Moreover, the existed bio-material binding agent Cell-TakTM, which is the extraction of Mfp-1 and Mfp-2 mixtures, but only one mg of the protein can be obtained from about 10000 mussels by natural extraction. Inefficiency and high cost of such natural extraction process has greatly restricted the application of MAPs.(yawel,2017[3]) Thus, we chose a recombinant mussel foot protein, Mgfp-5, which is easier to produce compared to the original protein.[6]During research, we also found that “Catechol such as Dopa and dopamine can be directly coupled to polymers with functional groups such As H2, COOH, and OH, through the formation of amide, urethan, and ester linkages.”[7]

Fig 4: The mechanism of DOPA modification. (sourced from passage [7])

Also, the abundance of DOPA can contribute to the healing and disinfection of the wound as “During catechol oxidation, reactive oxygen species (ROS) such as super oxide anion ( ¯) and hydrogen peroxide (H2O2) are generated” [7] and “The biological effects of ROS are highly concentration dependent and can range from beneficiary (i.e., promote wound healing, antimicrobial effects) to detrimental (i.e., chronic inflammation, tumor initiation) responses.” [7]. As bacterially synthesized mfp protein lacks dopa and other Catechol, we plan on express dopa by ourselves and test the effect based on the amount added, which will be discussed later in our design and future works.

This background information inspired us a lot throughout our project. See the design page for more!

Reference:

[1]: Strong underwater adhesives made by self-assembling multi-protein nanofibres

Chao Zhong1,2,3†, Thomas Gurry1,4, Allen A. Cheng1,2,3, Jordan Downey2,3, Zhengtao Deng1,2,3, Collin M. Stultz1,4,5 and Timothy K. Lu1,2,3,4*

[2]: Expression of Functional Recombinant Mussel Adhesive Protein Mgfp-5 in Escherichia coli;

Dong Soo Hwang,1,2 Hyo Jin Yoo,2 Jong Hyub Jun,3,4 Won Kyu Moon,3,4 and Hyung Joon Cha1,2*

[3]: Expression and functional evaluation of Mytilus galloprovincialis foot protein type 5 (Mgfp-5), the recombinant mussel adhesive protein

Yawei Lv, Yujing Zhang, Wenying Gao and Yingjuan Wang*

[4]: Yoo Seong Choi , Dong Gyun Kang , Seonghye Lim , Yun Jung Yang , Chang Sup Kim & Hyung Joon Cha (2011) Recombinant mussel adhesive protein fp-5 (MAP fp-5) as a bulk bioadhesive and surface coating material, Biofouling: The Journal of Bioadhesion and Biofilm Research, 27:7, 729-737, DOI: 10.1080/08927014.2011.600830

[5]: A Biomimetic Mussel-Inspired -Poly-l-lysine Hydrogel with Robust Tissue-Anchor and Anti-Infection Capacity

Rui Wang, Jingzhe Li, Wei Chen, Tingting Xu, Shifeng Yun, Zheng Xu, Zongqi Xu, Takashi Sato, Bo Chi,* and Hong Xu*

[6]: Recombinant mussel adhesive protein Mgfp-5 as cell adhesion biomaterial

Dong Soo Hwang a,b, Youngsoo Gim a, Dong Gyun Kang a, Yeon Kyu Kim a,b, Hyung Joon Cha a,∗

[7]: Mussel inspired adhesives and coatings

B.P.Lee, P.K. Forooshani,