polylysine
Also known as: Polylysine, poly-L-lysine, ε-poly-L-lysine, ε-PLL, PLL
Overview
Polylysine refers to polymers of the amino acid lysine, with ε-poly-L-lysine (ε-PLL) and poly-L-lysine (PLL) being the most studied forms. ε-PLL is naturally produced by certain bacteria, while PLL can be synthesized. It is primarily classified as a biopolymer with significant antimicrobial and bioactive properties. Its main applications are in biomedical fields, such as coatings to prevent bacterial adhesion, drug delivery systems, and tissue engineering. Polylysine is also utilized as a food preservative due to its bacteriostatic effects. It exhibits strong antibacterial activity, biocompatibility, and the ability to enhance cell adhesion. Research on polylysine is well-established in materials science and microbiology, focusing on its antimicrobial and biomedical applications. However, its role as a conventional dietary supplement or systemic therapeutic agent in humans is not well-researched, with most evidence coming from in vitro and animal studies.
Benefits
Polylysine primarily demonstrates strong antibacterial activity, particularly when combined with other materials like graphene oxide. Studies show bacteriostatic rates up to approximately 89% against pathogens such as Porphyromonas gingivalis, which is relevant for preventing peri-implant diseases. Poly-L-lysine coatings are also known to promote cell adhesion, which is beneficial in tissue engineering applications. Furthermore, polylysine exhibits good biocompatibility, with in vivo studies in models like zebrafish showing no significant toxicity. Its versatility extends to drug delivery, where poly-L-lysine-based nanoparticles have been developed for pH-sensitive, targeted therapeutic applications. While these effects are significant in vitro and in animal models, there is currently no direct evidence from human clinical trials to support specific population benefits or quantify clinical significance for human supplementation.
How it works
Polylysine exerts its primary antibacterial effects by disrupting bacterial cell membranes. Due to its polycationic nature, it interacts with the negatively charged bacterial cell surfaces, leading to membrane destabilization and ultimately bacterial death. In the context of cell adhesion, polylysine coatings promote the attachment of cells by providing a positively charged surface that interacts with negatively charged components of cell membranes. However, it can also interact with immune cells, potentially triggering pyroptosis (a form of programmed cell death) in certain immune cells like THP-1 cells under specific conditions, indicating a complex interaction with immune responses. Systemic absorption and bioavailability in humans are not well-understood, as polylysine is mainly studied as a surface coating or topical agent.
Side effects
Polylysine is generally considered safe for topical applications and as a food preservative, with low toxicity observed in animal models. However, its safety profile for systemic human use as a supplement is not well-established due to a lack of human clinical trials. No common or uncommon side effects have been reported in human studies. A rare potential side effect observed in vitro is the induction of immune cell pyroptosis (a form of programmed cell death) in certain immune cells (e.g., THP-1 cells) when exposed to poly-L-lysine-coated surfaces. This suggests a need for caution regarding potential immune responses if polylysine were to be used systemically. There are no documented drug interactions or established contraindications. Safety in special populations such as pregnant women, children, or immunocompromised individuals has not been studied.
Dosage
The minimum effective dose, optimal dosage ranges, and maximum safe dose for human use of polylysine are not established. Polylysine is not typically taken orally as a dietary supplement. Instead, it is primarily applied as a coating on surfaces or incorporated into nanoparticles for biomedical applications. Therefore, timing considerations for oral intake are not applicable. There are no form-specific recommendations for human consumption, nor are there any known required cofactors. Information regarding its absorption and bioavailability in humans is currently unknown, as research has focused on its topical and material science applications rather than systemic administration.
FAQs
Is polylysine safe for human consumption?
Polylysine is used as a food preservative and is generally recognized as safe in that context. However, its safety as a systemic supplement lacks clinical data.
Can polylysine be used as an antibiotic alternative?
It shows promising antibacterial properties in vitro and in implant coatings but is not approved or studied as a systemic antibiotic for human use.
Does polylysine have immune effects?
In vitro studies suggest it may induce immune cell pyroptosis, indicating potential immune modulation, but clinical relevance is unknown.
How is polylysine administered?
It is mostly used as surface coatings or in biomedical materials, not typically as an oral supplement.
Research Sources
- https://www.degruyter.com/document/doi/10.1515/biol-2022-0028/html?lang=en – This in vitro study investigated the effects of poly-L-lysine-coated surfaces on THP-1 immune cells, finding that it induced pyroptosis, a form of programmed cell death. The research suggests a potential for immune activation by poly-L-lysine, highlighting a possible adverse effect in immune cells, though its clinical context remains to be determined.
- https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2024.1381685/full – This 2024 study demonstrated that self-assembled graphene oxide and ε-poly-L-lysine coatings on titanium implants significantly reduced bacterial colonization, achieving up to an 89% bacteriostatic rate. The study, which included in vitro and in vivo (zebrafish) models, also reported no observed toxicity, supporting the use of this combination in antibacterial implant coatings.
- https://www.tandfonline.com/doi/full/10.1080/10717544.2018.1461957 – This research focused on the development of poly-L-lysine-based nanoparticles for pH-sensitive drug delivery. The study successfully synthesized these nanoparticles, demonstrating their potential for targeted therapeutic applications. This highlights the versatility of polylysine in biomedical applications, particularly in advanced drug delivery systems.
