title: Montmorillonite-chitosan-silver sulfadiazine nanocomposites for topical treatment of chronic skin lesions: in vitro biocompatibility, antibacterial efficacy and gap closure cell motility properties.
abstract: Silver compounds and especially silver sulfadiazine (AgSD) are reported as effective antimicrobial agents against almost all known bacteria, fungi and some viruses. However, AgSD has been shown to be cytotoxic toward fibroblasts and keratinocytes in vitro and consequently to retard wound healing in vivo. The aim of the present work was to evaluate the in vitro biocompatibility (cytotoxicity and proliferation), antimicrobial efficacy and cell motility gap closure (assay of wound closure) of MT/CS nanocomposites loaded with silver sulfadiazine (AgSD). It is envisioned to be administered as a powder or a dressing for cutaneous application in the treatment of skin ulcers. The loading of AgSD in MT/CS nanocomposites aimed at preventing the delay in wound healing, by decreasing the cytotoxicity of AgSD and maintaining its antimicrobial properties. Nanocomposites were prepared by using different amounts of MT (100-2000 mg) and 40 ml of a 1% (w/w) chitosan glutamate aqueous solution. The relative amounts of AgSD and chitosan in the systems were assessed by suitable analytic methods. The nanocomposite prepared using 100mg of MT was characterized for in vitro biocompatibility and proliferation and for wound healing using normal human dermal fibroblasts (NHDF). Antimicrobial properties were evaluated against four reference bacterial strains: Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa. AgSD loaded in the 100 MT/CS nanocomposite showed good in vitro biocompatibility and gap closure properties (fibroblasts) and maintained AgSD antimicrobial properties, especially against P. aeruginosa, that often complicates skin lesions.
authors: Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy. Electronic address: giuseppina.sandri@unipv.it.
authors: Giuseppina
authors: G
authors: Sandri
authors: Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
authors: Maria Cristina
authors: MC
authors: Bonferoni
authors: Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
authors: Franca
authors: F
authors: Ferrari
authors: Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
authors: Silvia
authors: S
authors: Rossi
authors: Department of Pharmacy and Pharmaceutical Technology, University of Granada, Campus of Cartuja, Granada, 18071 s/n, Spain.
authors: Carola
authors: C
authors: Aguzzi
authors: Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
authors: Michela
authors: M
authors: Mori
authors: Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
authors: Pietro
authors: P
authors: Grisoli
authors: Department of Pharmacy and Pharmaceutical Technology, University of Granada, Campus of Cartuja, Granada, 18071 s/n, Spain.
authors: Pilar
authors: P
authors: Cerezo
authors: Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
authors: Marika
authors: M
authors: Tenci
authors: Department of Pharmacy and Pharmaceutical Technology, University of Granada, Campus of Cartuja, Granada, 18071 s/n, Spain; Andalusian Institute of Earth Sciences, CSIC-University of Granada, Armilla, Granada, Spain.
authors: Cesar
authors: C
authors: Viseras
authors: Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy. Electronic address: carla.caramella@unipv.it.
authors: Carla
authors: C
authors: Caramella
mesh_terms: D000287:Administration, Topical; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001546:Bentonite / Q000737:chemistry*; D001672:Biocompatible Materials; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D048271:Chitosan / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D053761:Nanocomposites; D012837:Silver Sulfadiazine / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D001546:Bentonite; D048271:Chitosan; D012837:Silver Sulfadiazine
keywords: Antimicrobial properties; Chronic skin lesions; In vitro wound closure; Montmorillonite chitosan nanocomposites; Silver sulfadiazine