Fabrication and Facile Surface Derivatization of Poly(ε‐caprolactone)‐Based Wound Dressing Materials Imparting Anti‐Infective, Excessive Biofluid Drainage, and Easy‐to‐Peel Characteristics

Abstract

The rapid emergence of antimicrobial resistance warrants an antibiotic‐free approach to counter the bacterial threat in all possible applications of environmental and biomedical domains. In the context of smart wound dressing, besides imparting anti‐infective characteristics in a nonconventional fashion, it is also essential to imbibe multifunctional attributes like excessive biofluid drainage, easy‐to‐peel, optimal gas permeation, etc., for which appropriate material design is a prime requisite. In this work, poly(ε‐caprolactone) (PCL)− an FDA approved biocompatible polyester− is chosen for imparting antimicrobial properties by surface derivatization with molecularly‐dispersed ionic silver over quaternary ammonium moieties through a facile room temperate and organic solvent‐free approach. To render the other characteristics mentioned above, two different systems comprising PCL with varying porosity, namely, electrospun fibers and polyester‐coated cotton gauze, are developed. The dressing materials are thoroughly characterized and assessed for their structural, surface chemical, morphological, wettability, antibacterial, and peel strength properties as a function of surface derivatization steps. The bactericidal performance of the quaternary ammonium‐functionalized surfaces has enhanced manifold (≈7–10) after derivatizing with ionic silver. The in vivo efficacy study employing the dressing materials reveals ionic silver derivatized electrospun fibers as the most promising candidate, followed by cotton gauze‐coated with 5% PCL.

Probing the Effects of Antimicrobial‐Lysozyme Derivatization on Enzymatic Degradation of Poly(ε‐caprolactone) Film and Fiber

“…A clear shoulder-like broad peak was observed in all the samples in the scattering vector (q) values between 0.03 and 0.07 Å −1 , with the peak value appearing at ≈0.045 Å −1 . [17] These near-identical q values, appearing due to the long-range ordering in the crystalline lamellar repeat of the polymer samples, confirmed similar periodicity in both before and after enzymatically degraded PCL films and fibers. In brief, the enzymatic degradation did not affect the long-range order of the polymer samples; however, WAXS analysis revealed microstructural changes indicating preferential degradation along crystalline planes in PCL films but not in ES fibers.…”

“…[13] Electrospun fibers were crafted from 10% solution in chloroform:methanol (3:1) using an electrospinning apparatus (Gauge size: 18, flow rate: 0.2 mL min −1 , rotor spinning speed: 100 rpm, and voltage of 25 kV). [17] The viscosity of this solution was found to be 26 ± 2 mPa.s, as obtained using a Brookfield Rheometer. The as-fabricated films and fibers were vacuum dried in a desiccator for 24 h and sterilized under UV for 1 h, which were stored at room temperature in clean air-tight screw-capped falcons until further use.…”

“…Surface Derivatization of PCL Films and Electrospun Fibers: The fabrication and surface derivatization of PCL films and ES fibers were performed in a similar manner to that reported in the previous works. [13,17] Briefly, the films were made from 1% PCL solution in chloroform, cast into a clean glass petri dish, and air-dried at room temperature overnight. [13] Electrospun fibers were crafted from 10% solution in chloroform:methanol (3:1) using an electrospinning apparatus (Gauge size: 18, flow rate: 0.2 mL min −1 , rotor spinning speed: 100 rpm, and voltage of 25 kV).…”

“…It can be noted that the antibacterial activity of the lysozyme-derivatized PCL fibers is superior to the quaternary ammonium-functionalized ones reported in the literature. [17] Furthermore, the strategy can be synergistically integrated with complementary approaches like drugloaded polymer fibers and protein-derivatized antimicrobial microporous polymeric structures. [35,54]…”

“…[8][9][10][11] To circumvent these challenges, several antibiotic-free approaches are being actively pursued to impart antibacterial attributes to biomaterials that include derivatizing the surface with silver nanoparticles, ionic silver, quaternary ammonium functionality, and selenonium salt. [12][13][14][15][16][17][18][19] Despite their promising results, many of such components are considered foreign to the host's innate immune system. In this backdrop, imparting antimicrobial characteristics to biomedical implants closely emulating natural conditions is of prime importance.…”