Poly-L-lysine (PLL)

Poly-L-lysine (PLL) is a synthetic cationic homopolypeptide consisting of repeating units of the essential amino acid L-lysine [PubChem]. It is primarily recognized for its ability to mediate strong electrostatic interactions with negatively charged molecules and surfaces, such as the phosphate backbone of DNA or the glycocalyx of cell membranes [ScienceDirect]. In biomedical research, PLL is extensively used as a coating for glass and plastic cultureware to promote cell attachment and spreading [Sigma-Aldrich]. Beyond its role as a laboratory reagent, PLL serves as a versatile scaffold for drug and gene delivery systems, forming 'polyplexes' that protect nucleic acids from enzymatic degradation and facilitate their cellular uptake [PubMed]. It also possesses intrinsic antimicrobial properties, particularly against Gram-positive and Gram-negative bacteria, by disrupting the integrity of the bacterial cell wall through charge-based interactions [NIH]. However, the clinical utility of PLL is often limited by its molecular weight-dependent cytotoxicity and potential to induce hemolysis or systemic inflammatory responses [Journal of Controlled Release].

Other names

Poly(L-lysine)alpha-Poly-L-lysinePLLPoly-L-lysine hydrobromide

Poly-L-lysine acts via electrostatic attraction between its positively charged epsilon-amino groups and negatively charged biological components, such as the phosphate backbone of nucleic acids or the glycocalyx of cell membranes [ScienceDirect, NIH].