Photodynamic Therapy Interventions in Facial Photodamage: A Systematic Review

Skin rejuvenation through topical application of indocyanine green with diffractive optical element mode of 785 nm picosecond laser in Asian females

BACKGROUND

Indocyanine green (ICG) exhibits robust absorption near 800 nm.

AIMS

To examine the clinical effects of combining ICG with a 785 nm picosecond laser for treating photo-aged skin.

PATIENT/METHODS

A 785 nm 600 picosecond laser was used on the facial area of 16 female patients with Fitzpatrick skin type III and IV (mean age: 58.44 ± 5.24 years) after applying 0.0125% ICG cream. A total of 3000 shots were administered in diffractive optical element mode at a pulse energy of 200 mJ and frequency of 10 Hz. Hyperpigmented lesions were treated using the Zoom handpiece set at a spot size of 3-4 mm, pulse energy of 60-120 mJ, and frequency of 3-7 Hz. Patients underwent five sessions of treatment at intervals of 1-2 weeks. Wrinkles, pores and pigmented lesions were assessed at the initial assessment and 4 weeks after the final treatment using the Modified Fitzpatrick Wrinkle Scale and 10-point visual analog scale, respectively. Skin biopsy of the postauricular area was performed on two consenting patients.

RESULTS

Significant improvements in wrinkles (p = 0.02), pores (p = 0.034), and hyperpigmentation (p = 0.036) were observed, along with increased patient subjective improvement. Adverse effects were transient and well-tolerated. Hematoxylin and eosin and Masson's trichrome staining revealed increased and thickened dermal collagen fibers. Immunohistochemical staining revealed increased expression of collagen I and III throughout the papillary and upper reticular dermis, along with diffuse increase of STRO-1 in the dermis.

CONCLUSIONS

The combined application of a 785 nm picosecond laser and ICG yielded promising clinical outcomes for treating photo-aged skin in Asian patients with Fitzpatrick skin type III and IV.

5-aminolevulinic acid sonodynamic therapy for cutaneous squamous cell carcinoma

BACKGROUND

The treatment of deep-invasive cutaneous squamous cell carcinoma (cSCC) is difficult. Sonodynamic therapy (SDT) has showed advantages in large penetration depth, small trauma, good repeatability, high targeting selectivity and effective protection for intact structure and function of tissues and organs.

OBJECTIVE

To study the efficacy and safety of 5-aminolevulinic acid SDT (ALA-SDT) in the treatment of cSCC.

METHODS

The absorption and transformation of ALA after co-incubation with cSCC were detected by UV-Vis and fluorescence absorption. The production of reactive oxygen species (ROS) when protoporphyrin IX (PpIX) excited with ultrasound was detected by ROS detection probe. Cytotoxicity of ALA-SDT to cSCC was detected with cytotoxicity indicators. The tumor volume changes and tumor weight of mice after ALA-SDT were detected. The effects of ALA-SDT on the growth of mice were evaluated through the changes in body weight of mice. Biosafety of treatment was further evaluated by histopathology to determine whether the tissues and organs of mice were affected after ALA-SDT.

RESULTS

ALA can be absorbed and converted into PpIX when incubated with cSCC cells and produces ROS with ultrasound irradiation. ALA-SDT showed a significant cytotoxicity on cSCC cells. With one session of ALA-SDT in vivo, tumor growth was slowed but not stopped and would proceed once treatment was ended. ALA-SDT had no significant effect on body weight changes and major tissues and organs of the mice.

CONCLUSION

ALA-SDT could safely and reduce cSCC cells growth both in vitro and in vivo.

Positive effects of low-dose photodynamic therapy with aminolevulinic acid or its methyl ester in skin rejuvenation and wound healing: An update

In dermatology, photodynamic therapy (PDT) is widely used in skin tumors, infections, etc., because of the killing effect triggered by toxic reactive oxygen species (ROS). However, the ROS concentration is determined by various photosensitizer concentrations and formulations, as well as various irradiation parameters. Low-dose PDT leads to sufficiently low ROS level, which results in biological effects that are the exact opposite of the killing potency. Therefore, in recent years, low-dose PDT has been exploited in improving aging and wound. Low-dose ALA/MAL PDT might improve aging through promoting the proliferation of fibroblasts, blocking DNA damage, counteracting oxidative stress, inhibiting melanogenesis, and remodeling lymphatic vessels in aged skin. Promoting fibroblasts and epidermal stem cells proliferation and migration, promoting granulation tissue formation and angiogenesis and regulating the inflammatory process might be the mechanisms of low-dose ALA/MAL PDT in wound healing. Nevertheless, the positive effects of low-dose PDT have not been thoroughly investigated in dermatology, and high-quality studies are still needed to fill the relevant vacancy.

Visible light. Part I: Properties and cutaneous effects of visible light

Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.

Topical photodynamic therapy combined with ablative "light needles" against basal cell carcinoma

Basal cell carcinoma (BCC), a non-melanoma cancer with high morbidity in the elders, is a type of limited skin cancer with a projected appearance. Traditional treatments such as oral or injection administration are likely to result in serious side effects. Here, we developed a strategy that combined photodynamic therapy (PDT) with ablative light "needles" (carbon-dioxide laser) for the treatment of BCC, involving β-Tetra-(4-carboxyl-phenoxy)-zinc phthalocyanine (ZnPC₄) cubic phases with high drug loading, easy preparation, long local retention, good spreading ability and little toxicity. A model of nude mice with BCC was established for the study of pharmacodynamics. The light needles of low energy (53 mJ/cm²) used here could promote transdermal absorption of ZnPC₄ cubic phases while those of high energy (238 mJ/cm²) alone could completely kill tumor cells with no recurrence. However, ZnPC₄ cubic phases alone could not completely inhibit tumor growth, for it was distributed mainly at the topical administration site in the absence of any adjuvant technology. Therefore, the combination of photodynamics and light needles offered a good solution. Especially, the combined use of light needles with high energy and ZnPC₄ cubic phases can treat BCC efficiently with no recurrence. This approach is expected to be a novel and promising medication against BCC.