Antimicrobial functionalization of bacterial nanocellulose by loading with polihexanide and povidone-iodine

Abstract

Bacterial nanocellulose (BNC) is chemically identical with plant cellulose but free of byproducts like lignin, pectin, and hemicelluloses, featuring a unique reticulate network of fine fibers. BNC sheets are mostly obtained by static cultivation. Now, a Horizontal Lift Reactor may provide a cost efficient method for mass production. This is of particular interest as BNC features several properties of an ideal wound dressing although it exhibits no bactericidal activity. Therefore, BNC was functionalized with the antiseptics povidone-iodine (PI) and polihexanide (PHMB). Drug loading and release, mechanical characteristics, biocompatibility, and antimicrobial efficacy were investigated. Antiseptics release was based on diffusion and swelling according to Ritger-Peppas equation. PI-loaded BNC demonstrated a delayed release compared to PHMB due to a high molar drug mass and structural changes induced by PI insertion into BNC that also increased the compressive strength of BNC samples. Biological assays demonstrated high biocompatibility of PI-loaded BNC in human keratinocytes but a distinctly lower antimicrobial activity against Staphylococcus aureus compared to PHMB-loaded BNC. Overall, BNC loaded with PHMB demonstrated a better therapeutic window. Moreover, compressive and tensile strength were not changed by incorporation of PHMB into BNC, and solidity during loading and release could be confirmed.

Chitosan-Coated Collagen Membranes Promote Chondrocyte Adhesion, Growth, and Interleukin-6 Secretion

“…Thus, chitosan incorporation into the collagen sponge did not change the internal structure of this sponge. These data are comparable to those already obtained with bacterial cellulose functionalized with pectin [49] or aminoalkyl groups [50] or RGDC-gentamicin [51] showing reduced pore density but still interconnected [48]. The SEM analyses showing chitosan presence onto the collagen sponge was supported by XPS analyses.…”

Consensus on Wound Antisepsis: Update 2018

“…PHMB was effective against biofilm in vitro [90] and in animal models [91]. Loaded onto nanocellulose, PHMB was antimicrobially more effective than PVP-I [92]. No antagonism could be shown against oxacillin, penicillin G, ampicillin, cefazolin, cefuroxime, imipenem, gentamicin, erythromycin, doxycycline, levofloxacin, linezolid, or vancomycin [93].…”

Multiphotonic staging of chronic wounds and evaluation of sterile, optical transparent bacterial nanocellulose covering: A diagnostic window into human skin

“…20 Furthermore, it provides a lot of properties which are helpful in treatment of chronic wounds such as a well adherent behavior to the wound surface, it keeps a moist milieu to the wound, reduces pain during handling for wound treatment and expedites the process of granulation and reepithelization. 20 Furthermore, in comparison to stiff glass cover slips the BNC foil give the possibility to cover larger and topographic challenging skin areas. During measurements, it was observed, that BNC providing sterile skin covering has no negative influence on morphological images.…”