Polymeric Multilayers that Contain Silver Nanoparticles can be Stamped onto Biological Tissues to Provide Antibacterial Activity

Abstract

We report the design of polyelectrolyte multilayers (PEMs) that can be prefabricated on an elastomeric stamp and mechanically transferred onto biomedically-relevant soft materials, including medical-grade silicone elastomers (E′~450–1500 kPa; E′-elastic modulus) and the dermis of cadaver-skin (E′~200–600 kPa). Whereas initial attempts to stamp PEMs formed from poly(allylamine hydrochloride) and poly(acrylic acid) resulted in minimal transfer onto soft materials, we report that integration of micrometer-sized beads into the PEMs (thicknesses of 6–160 nm) led to their quantitative transfer within 30 seconds of contact at a pressure of ~196 kPa. To demonstrate the utility of this approach, PEMs were impregnated with a range of loadings of silver-nanoparticles and stamped onto the dermis of human cadaver-skin (a wound-simulant) that was subsequently incubated with bacterial cultures. Skin-dermis stamped with PEMs that released 0.25±0.01 μg cm−2 of silver ions caused a 6 log10 reduction in colony forming units of Staphylococcus epidermidis and Pseudomonas aeruginosa within 12 h. Significantly, this level of silver release is below that which is cytotoxic to NIH 3T3 mouse fibroblast cells. Overall, this study describes a general and facile approach for the functionalization of biomaterial surfaces without subjecting them to potentially deleterious processing conditions.

Carbon nanotube-based antimicrobial biomaterials formed via layer-by-layer assembly with polypeptides

“…of antimicrobial materials [14]. One focus has been immobilization or release of synthetic agents such as poly(ammonium salts), metal derivates, and antibiotics; inactivation rates of up to 6 log units have been reported [15][16][17][18][19][20][21]. Another focus has been bio-inspired approaches, such as antimicrobial peptides, bacteriolytic enzymes and essential oils [21,[41][42][43][44][45], where inactivation rates up to 98% have appeared [43,46].…”

“…bacteria), and are beginning to make an impact on public health [14][15][16][17][18][19][20][21]. With the rapid development of new biomedical devices and implants, antimicrobial surfaces are particularly important [22].…”

Laundering durable antibacterial cotton fabrics grafted with pomegranate-shaped polymer wrapped in silver nanoparticle aggregations

“…Recent work reveals that nanoscale forms of silver6789 (and other antibacterial metals, copper10 and zinc oxide11 for example) are particularly effective at deactivating bacterial growth. Although the general antibacterial mechanism of nanoscale metal-based antimicrobial agents is largely unclear, its ultra-small size and super-large specific area has been proposed as a main rationale1213141516.…”

Gallium‐Loaded Dissolvable Microfilm Constructs that Provide Sustained Release of Ga3+ for Management of Biofilms

“…The adsorption and rinsing steps were repeated until the desired number of multilayers was deposited, as described elsewhere. [23] Post fabrication, the PEMs were stored at ambient conditions.…”

“…We hypothesized that the polyeletrolyte multilayers (PEMs) could serve as nanometer-thick reservoirs for spatial confinement and localized delivery of Ga 3+ . We note that previously we reported the use of PEMs loaded with silver nanoparticles to release non-cytotoxic loadings of Ag + ions that killed planktonic bacteria in in vitro [22,23] and in vivo studies [24,25] . In this study, we move to explore ways to manage bacterial biofilms based on the localized delivery of Ga 3+ from PEMs.…”