Tuning the antimicrobial activity of collagen biomaterials through a liposomal approach

Abstract

The development of advanced biocidal agents stands as a global challenge, focused on the increasing demand of new biomaterials with local and gradual release of antimicrobial agents. This is the first time that three well‐known materials are strategically combined to develop a novel biomaterial with long‐term bactericidal activity that avoids burst release and toxic effects, by the incorporation of silver nanoparticles in liposomes and the subsequent incorporation of these assemblies in collagen hydrogels. These systems show improved mechanical properties and prolonged inhibitory effect on the growth of Gram‐positive (Staphylococcus aureus) and Gram‐negative (Pseudomonas aeruginosa) bacteria, while remaining highly biocompatible for epithelial cells. In fact, the hybrid biocomposite prevents bacterial colonization for at least 72 h, allowing at the same time eukaryotic cell proliferation. As a result, this new bactericidal biomaterial provides a new alternative to improve current treatments of bacterial infections with many implications in significant applications, such as wound therapy and tissue regeneration.

Collagen Hydrogels Loaded with Silver Nanoparticles and Cannabis Sativa Oil

“…This result is especially interesting as it demonstrates that the bacterial colonization of our hybrid collagen scaffold can be regulated over time with the concentration of the antimicrobial agent. A similar behavior was observed for the Col-L-AgNPs bactericidal effect which depends on the concentration of liposomal AgNPs added to collagen hydrogels, but also on the bacteria strain [ 7 ].…”

“…The antimicrobial activity of Col-AgNPs was also studied by the dilution method in order to evaluate the bactericidal effect of the material over time (from 24 h to 7 days). This method was also used in a previous work [ 7 ] in which silver nanoparticles were first incorporated in liposomes and then in collagen scaffolds (Col-L-AgNPs). Briefly, the collagen hydrogels containing three different concentrations of AgNPs (0.67, 6.7, and 67 mg/g) were incubated with a 1 × 10 5 CFU/mL bacterial suspension for 24 h and up to 7 days at 37 °C.…”

“…Therefore, during the last few years, different alternatives have been proposed to this end [ 4 ]. These include different biomaterials (i.e., collagen, chitosan) in combination with antibiotics, nanoparticles, antimicrobial peptides, or natural products [ 5 , 6 , 7 , 8 , 9 ].…”

“…In this sense, silver nanoparticles (AgNPs) have a well-known deleterious effect over a broad spectrum of Gram-positive and Gram-negative bacteria, including antibiotic-resistant ones [ 14 ]. Indeed, AgNPs are effective against Staphylococcus aureus and Pseudomonas aeruginosa which are the most frequent bacteria responsible for wound infection and biofilm formation [ 7 ]. The mechanism of silver antimicrobial activity involves the action over multiple targets including protein binding, nucleic acids complexation, inhibition of cell division, and reproduction.…”

Fabrication and insights into the mechanisms of collagen‐based hydrogels with the high cell affinity and antimicrobial activity

“…The increasing attentions on collagen-based hydrogels have been extensively obtained in wound dressings and tissue engineering fields due to their desired biocompatibility, controllable biodegradability and low immunogenicity. [1][2][3] In particular, the development of collagen-based hydrogels with specific function, such as tissue adhesiveness and antibacterial properties, have gained the sustaining interests. [4][5][6] Bacterial infections are often accompanied with the wound healing route, which lead to tissue morbidity and even sepsis in chronic wounds.…”