INL-International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga, 4715-330 Braga, Portugal.
Viruses. 2022 May 5;14(5):964. doi: 10.3390/v14050964.
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, phage vB_PaeM-SMS29, a phage with poor antibiofilm properties, was incorporated into polyvinyl alcohol (PVA, Mowiol 4:88) supplemented with 0.1% (/) 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 PAO1 biofilms by 2.44 to 2.76 log CFU·cm at 24 h. These values are significantly higher than the result obtained after the treatment with the free phage (1.09 log CFU·cm). 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.
耐药菌在大多数慢性皮肤伤口和其他生物膜相关的局部皮肤感染中占优势。噬菌体（噬菌体）已被证明在治疗不同的抗生素耐药和多药耐药细菌感染方面具有抗菌效果，但并非所有噬菌体都对生物膜有效。具有解聚酶的噬菌体可以到达不同的生物膜层；然而，那些没有解聚酶活性的噬菌体很难穿透和在错综复杂的 3D 生物膜结构中导航，主要感染位于外生物膜层中的细菌。为了解决这个问题，将噬菌体 vB_PaeM-SMS29 （一种具有较差抗生物膜特性的噬菌体）掺入到聚乙烯醇（PVA，Mowiol 4:88）中，并用 0.1%（/）甘油补充，并铸造成两种不同的几何形状各异的微针阵列。通过显微镜、力位移、溶胀、噬菌体释放和稳定性对溶解微针进行了彻底的表征。此外，使用集落生物膜程序（无肉汤）形成 48 小时龄的生物膜，并通过活菌计数和显微镜评估载噬菌体微针的抗生物膜效果，并与游离噬菌体进行比较。在 4°C 下储存时，微针中的噬菌体在六个月内相当稳定，仅观察到噬菌体滴度略有下降。微针的几何形状影响了穿透和力位移特性，但不影响对抗生物膜的抗菌效果。两种载有噬菌体的 PVA 微针在 24 小时内将 PAO1 生物膜减少了 2.44 至 2.76 log CFU·cm。这些值明显高于游离噬菌体处理后的结果（1.09 log CFU·cm）。总的来说，这项研究表明，使用溶解微针对生物膜进行机械破坏引起的噬菌体分布可以成为治疗局部生物膜相关皮肤感染的有效给药方法。
