Table 1.
Laboratory studies showing the effect of photodynamic therapy on keloids and hypertrophic scars.
| Study | Design | Treatment | Outcome |
|---|---|---|---|
| Liu et al., 2019 26 | In vitro | ALA PDT 633-nm red LED |
PDT beneficial ALA-PDT induced superoxide anion-dependent autophagic cell death |
| Hu et al., 2017 24 | In vitro | Hypocrellin B PDT yellow light from LED |
HB-LED PDT treatment induced significant keloid fibroblast apoptosis and decreased cell viability |
| Mendoza-Garcia et al., 2015 20 | Ex vivo | ALA or MALA PDT 633-nm red LED |
Post-PDT, matrix components were found to be reorganised in both hypertrophic and keloid scars. |
| Zheng et al., 2015 25 | In vitro | Pheophorbide a-based PDT 664-nm LED |
RUNX3 expression was detected more often in keloid tissues than in the dermis of normal skin. Significant differences were found after pheophorbide a-based PDT in RUNX3-expressing keloid fibroblasts |
| Mendoza et al., 2012 21 | In vitro | ALA or MALA PDT 633-nm red LED |
Cytotoxicity post-PDT in keloid fibroblasts is dependent on the lesional site, photosensitiser pro-drug and fluence |
| Sebastian et al., 2011 22 | In vitro | PDT + DW | Combination treatment is more effective than PDT on its own |
| Chiu et al., 2005 19 | In vitro | ALA PDT 633-nm Red LED |
The study established a PDT dosimetry range that reduces tissue contraction and collagen density while minimising injury to fibroblasts |
| Li et al. 2012 23 |
In vitro | ALA PDT 633-nm Red LED |
Hypertrophic scar-derived fibroblasts efficiently accumulate protoporphrin IX after ALA treatment and can be eliminated via apoptosis by red light |
ALA, 5-aminolevulinic acid; DW, degenerate wave; LED, light-emitting diode; MAL, methylaminolevulinate.