Sharklet (material)

Sharklet, manufactured by Sharklet Technologies, is a bio-inspired plastic sheet product structured to impede microorganism growth, particularly bacterial growth. It is marketed for use in hospitals and other places with a relatively high potential for bacteria to spread and cause infections.[1] Coating surfaces with Sharklet work due to the nano-scale texture of the product's surface.

The inspiration for Sharklet's texture came through analysis of the texture of shark skin, which does not attract barnacles or other biofouling, unlike ship hulls and other smooth surfaces. The texture was later found to also repel microbial activity.

HistoryEdit

Sharklet material is bio-inspired and was developed by Dr. Anthony Brennan, materials science and engineering professor at University of Florida, while trying to improve antifouling technology for ships and submarines at Pearl Harbor.[2]

Brennan realized that sharks do not experience fouling. He observed that shark skin denticles are arranged at the micrometre scale in a distinct diamond repeating micro-pattern with millions of tiny ribs.[2] The width-to-height ratio of shark denticle riblets corresponded to his mathematical model for the texture of a material that would discourage microorganisms from settling. The first test performed showed an 85% reduction in green algae settlement compared to smooth surfaces.[3]

TextureEdit

Sharklet's texture is a combination of “ridge” and “ravine” at a micrometer scale.

Resistance to bacterial attachmentEdit

Adherence prevention and translocation restriction have been demonstrated, and are believed to contribute significantly to restricting the risk of device-associated infections.

Sharklet's topography creates mechanical stress on settling bacteria, a phenomenon known as mechanotransduction. Nanoforce gradients caused by surface variations induces stress gradients within the lateral plane of the surface membrane of a settling microorganism during initial contact. This stress gradient disrupts normal cell functions, forcing the microorganism to provide energy to adjust its contact area on each topographical feature to equalize the stresses. This expenditure of energy is thermodynamically unfavorable to the settler, inducing it to search for a different surface to attach to.[4] Sharklet is made, however, with the same material as other plastics.

The physical arrangement enhances the hydrophobicity of the device surface such that the bacteria attachment energy is insufficient for adherence and/or colonization[citation needed].

Environmental surface contamination provides a potential reservoir for pathogens to persist and cause infection in susceptible patients. Microorganisms colonize biomedical implants by developing biofilms, structured communities of microbial cells embedded in an extracellular polymeric matrix that are adherent to the implant and/or the host tissues. Biofilms are an important threat to human health as they may harbor large numbers of pathogenic bacteria. Up to 80% of bacterial infections in humans involve microorganisms from biofilms, and biofilm formation on medical devices can lead to nosocomial infections and potentially higher mortality rate.[5] Indwelling of medical devices is associated with high risk of infection, given the abundance of bacterial flora on human skin and the risk of contamination from other sources, The fact that many of the pathogens responsible for these infections are multi-drug-resistant, or even panresistant, has become particularly problematic, with few treatment options being available to Healthcare workers and the industry are seeking safe and effective means to prevent device-associated infections.[6]

Sharklet micro-patterns can be incorporated onto the surfaces of a variety of medical devices during the manufacturing process. This micro-pattern is effective against bio-fouling and microbial attachment and is non-toxic. It therefore has potential to help infection control on medical devices such as per-cutaneous devices. Sharklet micro-patterns have been shown to control the bio-adhesion of a wide range of marine microorganisms, pathogenic bacteria and eukaryotic cells. They reduce S. aureus and S. epidermidis colonization after exposure to a simulated vascular environment by 70% or greater when compared to smooth controls. This micro-pattern similarly reduces platelet adhesion and fibrin sheath formation by approximately 80%.[7] An in vitro study demonstrated that it reduced the colonization of S. aureus and P. aeruginosa bacterial pathogens effectively.[6] Importantly, this infection control was achieved without the aid of antimicrobial agents.

See alsoEdit

ReferencesEdit

  1. ^ Kaluzny, Kasia, "How New Tech Fights Hospital Bugs", Hospital News
  2. ^ a b "'Inspired by Nature'". Sharklet Technologies Inc. 2010. Retrieved 6 June 2014.
  3. ^ Alsever, Jennifer (2013-05-31). "Sharklet: A biotech startup fights germs with sharks". CNN.com Money.
  4. ^ Schumacher, J. F.; Long, C. J.; Callow, M. E.; Finlay, J. A.; Callow, J. A.; Brennan, A. B. (2008). "Engineered Nanoforce Gradients for Inhibition of Settlement (Attachment) of Swimming Algal Spores". Langmuir. 24 (9): 4931–7. doi:10.1021/la703421v. PMID 18361532.
  5. ^ Kim, Eun; Kinney, William H.; Ovrutsky, Alida R.; Vo, Danthy; Bai, Xiyuan; Honda, Jennifer R.; Marx, Grace; Peck, Emily; Lindberg, Leslie; Falkinham, Joseph O.; May, Rhea M.; Chan, Edward D. (2014-09-09). "A surface with a biomimetic micropattern reduces colonization ofMycobacterium abscessus". FEMS Microbiology Letters. Oxford University Press (OUP). 360 (1): 17–22. doi:10.1111/1574-6968.12587. ISSN 0378-1097. PMID 25155501.
  6. ^ a b Xu, Binjie; Wei, Qiuhua; Mettetal, M. Ryan; Han, Jie; Rau, Lindsey; Tie, Jinfeng; May, Rhea M.; Pathe, Eric T.; Reddy, Shravanthi T.; Sullivan, Lauren; Parker, Albert E.; Maul, Donald H.; Brennan, Anthony B.; Mann, Ethan E. (2017-11-01). "Surface micropattern reduces colonization and medical device-associated infections". Journal of Medical Microbiology. Microbiology Society. 66 (11): 1692–1698. doi:10.1099/jmm.0.000600. ISSN 0022-2615. PMC 5903250. PMID 28984233.
  7. ^ May, Rhea M; Magin, Chelsea M; Mann, Ethan E; Drinker, Michael C; Fraser, John C; Siedlecki, Christopher A; Brennan, Anthony B; Reddy, Shravanthi T (2015-02-26). "An engineered micropattern to reduce bacterial colonization, platelet adhesion and fibrin sheath formation for improved biocompatibility of central venous catheters". Clinical and Translational Medicine. Springer Science and Business Media LLC. 4 (1): 9. doi:10.1186/s40169-015-0050-9. ISSN 2001-1326. PMC 4385044. PMID 25852825.

External linksEdit