Related Experiment Video
Updated: Mar 30, 2026
Investigation of a Blue Light LED Device to Suppress Wound Pathogens Using a Collagen-Based Synthetic Skin Model
Published on: February 24, 2026
Modulation of inflammatory response of wounds by antimicrobial photodynamic therapy
Khageswar Sahu1, Mrinalini Sharma1, Pradeep Kumar Gupta1
1Laser Biomedical Applications and Instrumentation Division, Raja Ramanna Centre for Advanced Technology, Indore.
Background And Aims:
Management of infections caused by Pseudomonas aeruginosa is becoming difficult due to the rapid emergence of multi-antibiotic resistant strains. Antimicrobial photodynamic therapy (APDT) has a lot of potential as an alternative approach for inactivation of antibiotic resistant bacteria. In this study we report results of our investigations on the effect of poly-L-lysine conjugate of chlorine p6 (pl-cp6) mediated APDT on the healing of P.aeruginosa infected wounds and the role of Nuclear Factor kappa B (NF-kB) induced inflammatory response in this process.
Materials And Method:
Excisional wounds created in Swiss albino mice were infected with ∼10(7) colony forming units of P.aeruginosa. Mice with wounds were divided into three groups: 1) Uninfected, 2) Infected, untreated control (no light, no pl-cp6), 3) Infected, APDT. After 24 h of infection (day 1 post wounding), the wounds were subjected to APDT [pl-cp6 applied topically and exposed to red light (660 ± 25 nm) fluence of ∼ 60 J/cm(2)]. Subsequent to APDT, on day 2 and 5 post wounding (p.w), measurements were made on biochemical parameters of inflammation [toll like receptor-4 (TLR-4), NF-kB, Inteleukin (IL)-[1α, IL-β, and IL-2)] and cell proliferation [(fibroblast growth factor-2 (FGF-2), alkaline phosphatase (ALP)].
Results:
In comparison with untreated control, while expression of TLR-4, NF-kB (p105 and p50), and proinflammatory interleukins (IL-1α, IL-1β,IL-2) were reduced in the infected wounds subjected to APDT, the levels of FGF-2 and ALP increased, on day 5 p.w.
Conclusion:
The measurements made on the inflammatory markers and cell proliferation markers suggest that APDT reduces inflammation caused by P.aeruginosa and promotes cell proliferation in wounds.
Insights
Antimicrobial photodynamic therapy (APDT) effectively healed Pseudomonas aeruginosa infected wounds in mice. This approach reduced inflammation and promoted cell proliferation, offering a promising alternative for antibiotic-resistant bacterial infections.
Area of Science:
- Wound Healing Research
- Antimicrobial Therapy
- Inflammation Biology
Background:
- Multi-antibiotic resistant Pseudomonas aeruginosa strains pose a significant challenge in infection management.
- Antimicrobial photodynamic therapy (APDT) presents a potential alternative for combating antibiotic-resistant bacteria.
Purpose of the Study:
- To investigate the efficacy of poly-L-lysine conjugate of chlorine p6 (pl-cp6) mediated APDT on P. aeruginosa infected wound healing.
- To explore the role of Nuclear Factor kappa B (NF-kB) induced inflammatory response in APDT-treated wounds.
Main Methods:
- Excisional wounds in mice infected with P. aeruginosa were treated with topical pl-cp6 and red light (660 nm).
- Inflammatory markers (TLR-4, NF-kB, ILs) and cell proliferation markers (FGF-2, ALP) were measured on days 2 and 5 post-wounding.
Main Results:
- APDT significantly reduced the expression of TLR-4, NF-kB, and pro-inflammatory interleukins (IL-1α, IL-1β, IL-2) in infected wounds.
- Levels of fibroblast growth factor-2 (FGF-2) and alkaline phosphatase (ALP) increased in APDT-treated wounds by day 5 post-wounding.
Conclusions:
- APDT effectively reduces inflammation associated with P. aeruginosa wound infections.
- The study suggests APDT promotes cell proliferation, aiding in wound healing.
