Antibiofilm Efficacy of the Pseudomonas aeruginosa Pbunavirus vB_PaeM-SMS29 Loaded onto Dissolving Polyvinyl Alcohol Microneedles

Abstract

Resistant bacteria prevail in most chronic skin wounds and other biofilm-related topical skin infections. Bacteriophages (phages) have proven their antimicrobial effectiveness for treating different antibiotic-resistant and multidrug-resistant bacterial infections, but not all phages are effective against biofilms. Phages possessing depolymerases can reach different biofilm layers; however, those that do not have depolymerase activity struggle to penetrate and navigate in the intricate 3D biofilm structure and mainly infect bacteria lodged in the outer biofilm layers. To address this, Pseudomonas aeruginosa phage vB_PaeM-SMS29, a phage with poor antibiofilm properties, was incorporated into polyvinyl alcohol (PVA, Mowiol 4:88) supplemented with 0.1% (v/v) of glycerol, and cast onto two different microneedle arrays varying in geometry. The dissolving microneedles were thoroughly characterized by microscopy, force-displacement, swelling, phage release and stability. Furthermore, 48 h-old biofilms were formed using the colony biofilm procedure (absence of broth), and the antibiofilm efficacy of the phage-loaded microneedles was evaluated by viable cell counts and microscopy and compared to free phages. The phages in microneedles were fairly stable for six months when stored at 4 °C, with minor decreases in phage titers observed. The geometry of the microneedles influenced the penetration and force-displacement characteristics but not the antimicrobial efficacy against biofilms. The two PVA microneedles loaded with phages reduced P. aeruginosa PAO1 biofilms by 2.44 to 2.76 log10 CFU·cm−2 at 24 h. These values are significantly higher than the result obtained after the treatment with the free phage (1.09 log10 CFU·cm−2). Overall, this study shows that the distribution of phages caused by the mechanical disruption of biofilms using dissolving microneedles can be an effective delivery method against topical biofilm-related skin infections.

Levofloxacin‐Loaded Microneedles Produced Using 3D‐Printed Molds for Klebsiella Pneumoniae Biofilm Control

“…Moreover, MNs are an attractive choice for biofilm infections since they can penetrate the extracellular polymeric matrix barrier and deliver the loaded antimicrobial into the biofilm interior. [ 29,52,53 ]…”

“…Antibiofilm Activity of LVX-Loaded PVA MNs: The activity of LVX-loaded MNs was evaluated against 24 h biofilms of K. pneumoniae PC28. Biofilms were produced according to the colony biofilm procedure, [29] with some modifications. Briefly, overnight cultures of K. pneumoniae were diluted to an approximate concentration of 1 × 10 8 CFU mL −1 .…”

“…Moreover, MNs are an attractive choice for biofilm infections since they can penetrate the extracellular polymeric matrix barrier and deliver the loaded antimicrobial into the biofilm interior. [29,52,53] The viable cells reached a concentration of 9.76 log 10 CFU mL −1 (Figure 7a). As expected, LVX-loaded MNs significantly reduced K. pneumoniae biofilm cells only at LVX concentrations ≥32 μg mL −1 (P ≤ 0.05) compared to the unloaded MNs.…”

“…This is because the polyvinyl alcohol used is known to dissolve quickly (7-11 min). [29] The MNs can, therefore, deliver a high amount of antibiotic quickly, resulting in higher bioavailability and faster onset of action than, for instance, topical creams and transdermal patches. It is reported that only 10-20% of drugs applied using topical creams can permeate across the skin.…”

“…[28]), and even bacteriophages. [ 29 ] These are entirely or almost wholly dissolved once inserted into the skin. The materials used for this are water‐soluble ones, including, for instance, maltose, dextran, and hyaluronic acid.…”