Optimization and integration of nanosilver on polycaprolactone nanofibrous mesh for bacterial inhibition and wound healing in vitro and in vivo

Abstract

Bacterial infection is a major hurdle to wound healing, and the overuse of antibiotics have led to global issue, such as emergence of multidrug-resistant bacteria, even “super bacteria”. On the contrary, nanosilver (NS) can kill bacteria without causing resistant bacterial strains. In this study, NS was simply generated in situ on the polycaprolactone (PCL) nanofibrous mesh using an environmentally benign and mussel-inspired dopamine (DA). Scanning electron microscopy showed that NS uniformly formed on the nanofibers of PCL mesh. Fourier transform infrared spectroscopy revealed the step-by-step preparation of pristine PCL mesh, including DA coating and NS formation, which were further verified by water contact angle changing from hydrophobic to hydrophilic. To optimize the NS dose, the antibacterial activity of PCL/NS against Staphylococcus aureus , Escherichia coli and Acinetobacter baumannii was detected by bacterial suspension assay, and the cytotoxicity of NS was evaluated using cellular morphology observation and Cell Counting Kit-8 (CCK8) assay. Then, inductively coupled plasma atomic emission spectrometry exhibited that the optimized PCL/NS had a safe and sustained silver release. Moreover, PCL/NS could effectively inhibit bacterial infection in an infectious murine full-thickness skin wound model. As demonstrated by the enhanced level of proliferating cell nuclear antigen (PCNA) in keratinocytes and longer length of neo-formed epidermis, PCL/NS accelerated wound healing by promoting re-epithelialization via enhancing keratinocyte proliferation in infectious wounds.

Antibacterial Activities of Aliphatic Polyester Nanocomposites with Silver Nanoparticles and/or Graphene Oxide Sheets

“…AgNPs can also be deposited on electrospun PCL fibers by means of coating process [149,182,183]. Nhi et al electrospun PCL nanofibers followed by air plasma treatment.…”

“…More recently, Liu et al electrospun PCL fibrous mats, immersed them in a dopamine (DA) solution followed by final dipping in AgNO 3 solutions of 0.5 mM, 1 mM and 2 mM concentrations [183]. Dopamine with its mussel adhesive behavior was used to reduce silver ions to AgNPs and then deposited them on the material surfaces [184].…”

<p>Fabrication of KR-12 peptide-containing hyaluronic acid immobilized fibrous eggshell membrane effectively kills multi-drug-resistant bacteria, promotes angiogenesis and accelerates re-epithelialization</p>

“…For SEM analysis, the sample was fixed in 4% formaldehyde, dehydrated with an ethanol solution and sputter-coated with gold. The area of biofilm was then measured using IPP 6.0 software based on SEM images as reported previously 41. For the Live/Dead staining assay, the sample was stained by a Live/Dead staining kit (Invitrogen, USA) in the dark for 15 mins.…”

Fabrication and characterization of tretinoin-loaded nanofiber for topical skin delivery

“…In pure PCL peaks at 2864 cm − 1 and 2942 cm − 1 represent stretching vibrations of CH 2 , the peak in 1722 cm − 1 attributes to stretching vibrations of C=O and band in 1000-1300 cm − 1 indicates stretching vibrations of the C-O-C group of the PCL backbone. The peak in 3438 cm − 1 depicts O-H stretching vibrations, the band in 2324 cm − 1 corresponds to C=O stretching and peaks at 960 cm − 1 shows the trans vinyl (CH=CH) groups of tretinoin molecule [14][15][16][17][18][19].…”