title: Effect of poly-L-lysine-chlorin P6-mediated antimicrobial photodynamic treatment on collagen restoration in bacteria-infected wounds.
abstract: OBJECTIVE
  The purpose of this work was to study the effect of poly-L-lysine-conjugated chlorin P6 (pl-cp6)-mediated antimicrobial photodynamic treatment (APDT) on collagen remodeling of murine excisional wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PAO).
  
  
  BACKGROUND
  Bacterial infection of wounds leads to compromised collagen remodelling. APDT-induced inactivation of bacteria and bacterial proteases are expected to restore collagen remodeling in wounds. However, published reports on the effect of PDT on wound healing are somewhat contradictory. One of the reasons for these observations could be the random sampling of wound repair outcomes by invasive technques such as histology.
  
  
  METHODS
  Post-wounding time-dependent changes in collagen restoration were monitored noninvasively using polarization sensitive optical coherence tomography (PSOCT) and compared with histology and hydroxyproline level. Immunoblotting was performed to study matrix metalloproteinase (MMP) level.
  
  
  RESULTS
  As indicated by retardance measurements from PSOCT images and immunoblotting, bacteria-infected wounds showed slower collagen restoration and higher MMP-8, 9 expression, than did uninfected wounds. In contrast, in infected wounds treated with pl-cp6 and light, retardance was higher (approximately twofold) compared with wounds treated with pl-cp6 alone. These results were consistent with lower MMP-8, 9 level on day 5, more ordered collagen matrix, and higher hydroxyproline content (approximately threefold) on day 18, observed in photodynamically treated wounds, compared with that of untreated infected wounds.
  
  
  CONCLUSIONS
  APDT expedites healing in bacteria-infected wounds in mice by attenuating collagen degradation and by enhancing epithelialization, hydroxyproline content, and collagen remodelling.
authors.affiliation: 1 Laser Biomedical Applications and Instrumentation Division , Raja Ramanna Centre for Advanced Technology, Madhya Pradesh, India .
authors.forename: Khageswar
authors.initials: K
authors.lastname: Sahu
authors.forename: Mrinalini
authors.initials: M
authors.lastname: Sharma
authors.forename: Priyanka
authors.initials: P
authors.lastname: Sharma
authors.forename: Yogesh
authors.initials: Y
authors.lastname: Verma
authors.forename: Kompalli Divakar
authors.initials: KD
authors.lastname: Rao
authors.forename: Harsha
authors.initials: H
authors.lastname: Bansal
authors.forename: Alok
authors.initials: A
authors.lastname: Dube
authors.forename: Pradeep Kumar
authors.initials: PK
authors.lastname: Gupta
mesh_terms: D000818:Animals; D003094:Collagen / Q000528:radiation effects*; D055624:Methicillin-Resistant Staphylococcus aureus; D051379:Mice; D010778:Photochemotherapy; D011107:Polylysine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D013203:Staphylococcal Infections / Q000188:drug therapy; D014945:Wound Healing / Q000528:radiation effects*; D014946:Wound Infection / Q000188:drug therapy* / Q000382:microbiology
chemical_list: C513585:polylysine-chlorin(E6) conjugate; D011107:Polylysine; D003094:Collagen