Premium
Photodynamic therapy on keloid fibroblasts in tissue‐engineered keratinocyte‐fibroblast co‐culture
Author(s) -
Chiu Lynn L.,
Sun Chung Ho,
Yeh Alvin T.,
Torkian Behrooz,
Karamzadeh Amir,
Tromberg Bruce,
Wong Brian J.F.
Publication year - 2005
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20213
Subject(s) - photodynamic therapy , viability assay , keratinocyte , wound healing , fibroblast , keloid , photosensitizer , pathology , chemistry , medicine , cell , in vitro , surgery , biochemistry , organic chemistry
Background and Objectives Keloids are disfiguring, proliferative scars that are a pathologic response to cutaneous injury. An organotypic tissue culture system (the Raft model 1–10) was used to investigate the feasibility of using photodynamic therapy (PDT) as an adjunctive therapy to treat keloids following surgical excision. The Raft co‐culture system mimics skin by layering keratinocytes on top of fibroblasts embedded in a collagen matrix. PDT uses drugs that produce singlet oxygen in situ when irradiated by light, and may lead to a number of effects in living tissues varying from the modulation of growth to apoptosis. PDT is already used to treat several benign and malignant diseases in organs such as the skin, retina, and esophagus. Study Design/Materials and Methods Normal adult, neonatal, and keloid fibroblasts and keratinocytes were isolated from skin obtained from patients undergoing elective procedures and used to construct the Raft s. Mature Rafts (after 4 days) were incubated with 5‐amino levulinic acid (5‐ALA), a photosensitizer, for 3 hours and were laser‐irradiated (635 nm) for total energy delivery of 5 J/cm 2 , 10 J/cm 2 , or 20 J/cm 2 . Rafts were examined 24 hours and 14 days later. Cell viability was determined using confocal imaging combined with live‐dead fluorescent dyes. Multi‐photon microscope (MPM) imaged collagen structure and density. As Rafts contract over time, surface area was measured using optical micrometry daily. Results At 10 and 20 J/cm 2 , near‐total cell death was observed in all constructs, while at 5 J/cm 2 cell viability was comparable to controls. Cell viability in keloid and neonatal Raft s was greater than that observed in normal adult Raft s. Treated Raft s contracted less over the 14‐day period compared to controls. Contraction and collagen density were greatest in keloid and neonatal Raft s. Conclusions A PDT dosimetry range was established, which reduces tissue contraction and collagen density while minimizing injury to fibroblasts. © 2005 Wiley‐Liss, Inc.