Optimization and Evaluation of a Chitosan/Hydroxypropyl Methylcellulose Hydrogel Containing Toluidine Blue O for Antimicrobial Photodynamic Inactivation

Photodynamic inactivation (PDI) combined with chitosan has been shown as a promising antimicrobial approach. The purpose of this study was to develop a chitosan hydrogel containing hydroxypropyl methylcellulose (HPMC), chitosan and toluidine blue O (TBO) to improve the bactericidal efficacy for topical application in clinics. The PDI efficacy of hydrogel was examined in vitro against the biofilms of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). Confocal scanning laser microscopy (CSLM) was performed to investigate the penetration level of TBO into viable S. aureus biofilms. Incorporation of HMPC could increase the physicochemical properties of chitosan hydrogel including the hardness, viscosity as well as bioadhesion; however, higher HMPC concentration also resulted in reduced antimicrobial effect. CSLM analysis further demonstrated that higher HPMC concentration constrained TBO diffusion into the biofilm. The incubation of biofilm and hydrogel was further performed at an angle of 90 degrees. After light irradiation, compared to the mixture of TBO and chitosan, the hydrogel treated sample showed increased PDI efficacy indicated that incorporation of HPMC did improve antimicrobial effect. Finally, the bactericidal efficacy could be significantly augmented by prolonged retention of hydrogel in the biofilm as well as in the animal model of rat skin burn wounds after light irradiation.

[1]  Yee-Chun Chen,et al.  The Use of Chitosan to Enhance Photodynamic Inactivation against Candida albicans and Its Drug-Resistant Clinical Isolates , 2013, International journal of molecular sciences.

[2]  Nizar M. Mhaidat,et al.  In vitro determination of the antibiotic susceptibility of biofilm-forming Pseudomonas aeruginosa and Staphylococcus aureus: possible role of proteolytic activity and membrane lipopolysaccharide , 2013, Infection and drug resistance.

[3]  T. Tsai,et al.  Chitosan Augments Photodynamic Inactivation of Gram-Positive and Gram-Negative Bacteria , 2011, Antimicrobial Agents and Chemotherapy.

[4]  M. Martinelli,et al.  In Vitro Resistance Selection Studies of RLP068/Cl, a New Zn(II) Phthalocyanine Suitable for Antimicrobial Photodynamic Therapy , 2009, Antimicrobial Agents and Chemotherapy.

[5]  Giulio Jori,et al.  Photodynamic therapy in the treatment of microbial infections: Basic principles and perspective applications , 2006, Lasers in surgery and medicine.

[6]  Michael R Hamblin,et al.  Photodynamic therapy: a new antimicrobial approach to infectious disease? , 2004, Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology.

[7]  M. Wainwright,et al.  Photosensitising agents - Circumventing resistance and breaking down biofilms: A review , 2004 .

[8]  K. Khanvilkar,et al.  Influence of Hydroxypropyl Methylcellulose Mixture, Apparent Viscosity, and Tablet Hardness on Drug Release Using a 23 Full Factorial Design , 2002, Drug development and industrial pharmacy.

[9]  M. Hamilton,et al.  A repeatable laboratory method for testing the efficacy of biocides against toilet bowl biofilms , 2001, Journal of applied microbiology.

[10]  N A Peppas,et al.  Modeling of drug release from delivery systems based on hydroxypropyl methylcellulose (HPMC). , 2001, Advanced drug delivery reviews.

[11]  David S. Jones,et al.  Development and Mechanical Characterization of Bioadhesive Semi-Solid, Polymeric Systems Containing Tetracycline for the Treatment of Periodontal Diseases , 1996, Pharmaceutical Research.

[12]  David S. Jones,et al.  Texture profile analysis of bioadhesive polymeric semisolids: Mechanical characterization and investigation of interactions between formulation components , 1996 .

[13]  F. Ferrari,et al.  Description and validation of an apparatus for gel strength measurements , 1994 .

[14]  M. R. Brown,et al.  Sensitivity of biofilms to antimicrobial agents. , 1993, The Journal of applied bacteriology.

[15]  John E. Hogan,et al.  Importance of drug type, tablet shape and added diluents on drug release kinetics from hydroxypropylmethylcellulose matrix tablets , 1987 .

[16]  M. H. Rubinstein,et al.  Formulation of sustained release promethazine hydrochloride tablets using hydroxypropyl-methylcellulose matrices , 1985 .

[17]  W. Altemeier,et al.  Relative roles of burn injury, wound colonization, and wound infection in induction of alterations of complement function in a guinea pig model of burn injury. , 1984, The Journal of trauma.

[18]  D. Gray,et al.  The surface tension of aqueous hydroxypropyl cellulose solutions , 1978 .

[19]  R. Gurny,et al.  A novel thermoresponsive hydrogel based on chitosan. , 2008, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.