Molecular Weight and Charge Density Effects of Guanidinylated Biodegradable Polycarbonates on Antimicrobial Activity and Selectivity

Abstract

Six guanidine functionalized aliphatic biodegradable polycarbonates with varying molecular weights and charge densities were synthesized via postsynthesis modification of alkyne containing polycarbonates using Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry. The concept of passive diluting group was to modify the cationic charge density of the polycarbonate without changing its hydrophilicity. Within the molecular weight range from 8000 to 30000 g mol, these guanidine polycarbonates exhibited broad-spectrum biocidal activity with low toxicity to red blood cells (RBCs). The lowest molecular weight homopolymer sample (PG-8k-100) showed the best antimicrobial activity (MIC = 40 μg/mL against Escherichia coli and MIC = 20 μg/mL against Staphylococcus epidermidis) and least RBC toxicity (0.6% hemolysis at MIC). Within the three guanidine charge densities from 20% to 70%, the low to medium dilution samples (PG-8k-7030 and PG-8k-5050) had no obvious loss in antimicrobial activities compared to the nondiluted control sample PG-8k-100. However, upon further dilution, PG-8k-2080 gave the lowest antimicrobial activity.

Influence of poly‐l‐lysine molecular weight on antibacterial efficacy in polymer multilayer films

“…However, the antibacterial activity decreased for PLL 400 . Structure–activity relationship studies have shown that some antibacterial polycations, including guanidinylated polycarbonates (8–30 kDa) and guanylated polymethacrylates (3–20 kDa), are more effective at lower than higher MW. This difference has been attributed to the sieving effect of the bacterial membrane, reducing the ability of larger polymers to penetrate the membrane .…”

Fast Hydrolytically Degradable 3D Printed Object Based on Aliphatic Polycarbonate Thiol‐Yne Photoresins

“…Aliphatic polycarbonates are well known for their degradability and biocompatibility. [ 34,35 ] Therefore, our “yne” component design is based on this polymer backbone. In 2016, Griesser's group reported the hydrolytic biodegradable photopolymers for the 3D printing of biomedical materials based on thiol‐yne click chemistry.…”

l-Arginine Grafted Poly(Glycerol Sebacate) Materials: An Antimicrobial Material for Wound Dressing

“…In the 1980s, the idea that positively charged material has unique physiological effects to reduce the colony formation of bacteria was first proposed, and has become a key concept in the design of antimicrobial materials in recent decades. It is worth noting that the proper density of positive charges is one of the key factors for successful antimicrobial activity [ 11 , 20 , 21 , 22 , 23 , 24 ]. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most common microbes that commonly lead to infections on wounds, and are also used to examine the antimicrobial function of materials in many studies [ 25 , 26 , 27 ].…”

“…In the 1980s, the idea that positively charged material has unique physiological effects to reduce the colony formation of bacteria was first proposed, and has become a key concept in the design of antimicrobial materials in recent decades. It is worth noting that the proper density of positive charges is one of the key factors for successful antimicrobial activity [11,[20][21][22][23][24]. Pseudomonas…”