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.
Department of Biochemical Science and Technology, National Taiwan University, Taipei 106, Taiwan. d00b22004@ntu.edu.tw.
Chueh-Pin
CP
Chen
Department of Cosmetic Science, Providence University, Taichung City 433, Taiwan. chienming.hsieh@gmail.com.
Chien-Ming
CM
Hsieh
Graduate Institute of Biomedical Materials and Tissue Engineering, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan. tmtsai00@gmail.com.
Tsuimin
T
Tsai
School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan. yang820065@tmu.edu.tw.
Jen-Chang
JC
Yang
Department of Biochemical Science and Technology, National Taiwan University, Taipei 106, Taiwan. chintin@ntu.edu.tw.
Chin-Tin
CT
Chen
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D018441:Biofilms / Q000187:drug effects; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000737:chemistry*; D004195:Disease Models, Animal; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D065347:Hypromellose Derivatives / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D051381:Rats; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects; D014048:Tolonium Chloride / Q000008:administration & dosage*; D014783:Viscosity
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D017319:Photosensitizing Agents; D014048:Tolonium Chloride; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D065347:Hypromellose Derivatives; D048271:Chitosan
chitosan; hydrogel; photodynamic inactivation; toluidine blue O