ALA Incubation Research Articles

Modified Painless Photodynamic Therapy for Actinic Keratosis in China

SignificanceAminolevulinic acid photodynamic therapy (ALA-PDT) is an effective treatment for actinic keratosis (AK). However, the pain during illumination usually caused patient to discontinue PDT treatment and resulted lower efficacy. Previous study showed modified painless PDT (M-PDT) with short ALA incubation time and longer irradiation time can reduce pain and preserve the efficacy. If M-PDT worked in AK still need to investigate. ApproachA splie-face controlled clinical study was conducted. Eleven patients with facial AK received C-PDT (conventional PDT) on the left and M-PDT in the contralateral area. The left area was illuminated by a red LED light (a total light dose of 140 J/cm2) after applying the ALA cream for 3 hours; the other had illumination for a total light dose of 288 J/cm2 after applying the ALA cream for 0.5 hours. The primary endpoint was the lesion clearance rate at 1 month. Secondary endpoints included pain scores, the incidence of adverse events, and cosmetic outcomes. ResultsAt one month following 3 treatments, the lesion clearance rate of M-PDT was non-inferior to that of C-PDT (93.1% vs. 86.4%, respectively. The lesion clearance rate of M-PDT to reach 100% clearance earlier than C-PDT for grade I lesions and higher clearance rates for grade III lesions. Moreover, the pain score during illumination was significantly lower for M-PDT than for C-PDT (P < 0.01). Regarding photoaging, the Global Subjective Skin Aging Assessment (GS2A2) score showed that the total and atrophy scores of C-PDT and M-PDT were significantly improved, and M-PDT also reduced discoloration. There was no significant difference in adverse reactions between C-PDT and M-PDT. ConclusionsM-PDT is non-inferior to C-PDT in terms of efficacy for treating AK, resulting in much lower pain scores.

Clinical practice Guidelines for 5-Aminolevulinic acid photodynamic therapy for acne vulgaris in China.

A variety of evidence suggest that 5-Aminolevulinic acid-based photodynamic therapy (ALA-PDT) is clinically effective in management of acne vulgaris. Several clinical guidelines for acne recommend PDT as an alternative treatment modality for severe acne. However, there is a lack of detailed clinical guideline for PDT in acne treatment. To propose up-to-date, evidence-based and practical recommendations on application of ALA-PDT for acne vulgaris, dermatologists and PDT experts from the Photodynamic Therapy Research Center of the CMA and Photodynamic Therapy Rehabilitation Training Center of CARD achieved consensus and guidelines based on careful evaluation of published literature, expert opinions and experience. ALA-PDT plays a therapeutic role in all four major pathogenesis of acne, and is suitable for moderate to severe acne and scar-prone acne, especially for patients who cannot tolerate or refused systemic antibiotics and isotretinoin. The efficacy and adverse reactions of ALA-PDT are closely related to therapeutic parameters including ALA concentration, incubation time, light source and dosage. Proper pretreatment helps to improve transdermal absorption of ALA and enhances its efficacy. We reviewed and proposed recommended protocols for four PDT procedures including conventional PDT (C-PDT), modified painless PDT (M-PDT), intense pulsed light PDT (IPL-PDT) and daylight PDT (DL-PDT). M-PDT with lower ALA concentration (3-5%), shorter incubation time (30 mins), and lower dose but prolonged illumination (630nm, 40-60 mW/cm2, 150 J/cm2) can improve lesions of moderate to severe acne vulgaris effectively with minimal pain and easier manipulation, and thus was recommended by Chinese dermatologists. Lastly, management of adverse reactions were addressed.

5-ALA loaded self-adhesive patch-PDT is effective and safe in the treatment of actinic keratoses on hands and arms.

Photodynamic therapy (PDT) with 5-aminolevulinic acid hydrochloride (ALA) is an established method for the management of AK. PD P 506 A (brand name Alacare®) is an approved medicinal product for the treatment of AK located on scalp and face. It is a self-adhesive, light-proof patch loaded with 5-ALA HCl and was developed for easy handling. AK located on arms, hands or trunk do not respond as well to ALA-PDT as AK lesions on the head do. It has been reported that occlusion during ALA incubation can improve clinical outcome after ALA-PDT for AK on hands and arms. We present the results of a first explorative pilot study involving 20 participants with a total of 145 treated (122 evaluable) AK lesions. The trial investigated the conduct of two ALA-PDTs within 1-2 weeks and involved all severity grades of AK. The model-based percentage of complete clearance on lesion-basis was estimated being 78.0% (95%-CI: [64.6%, 87.3%]), and the by-participant calculation (patient-based clearance) led to similar results (78.7% with a 95%-CI of [67.0%, 90.3%]). The treatment was well tolerated. Local reactions during ALA patch incubation were rare whereas nearly all patients showed the expected reactions during or after the illumination, primarily erythema and pain. The study results indicate that two PD P 506 A-PDT sessions 1-2 weeks apart are an efficacious treatment for AK on hands and arms. Especially mild but also moderate lesions responded very well to PDT treatment involving ALA incubation under occlusion.

Inflammation burst after 5-aminolevulinic acid-photodynamic therapy for the treatment of actinic keratosis complicating rosacea: A case report

A 72-year-old woman suffering from multiple actinic keratosis (AK) complicating steroid-induced rosacea received 5-aminolevulinic acid-photodynamic therapy (ALA-PDT) in our outpatient clinic. Both AKs and rosacea achieved remission after one session of PDT. However, an adverse effect of severe acute inflammatory response emerged with lasting hyperpigmentation. We then terminated the following PDT sessions . After skin care and close follow-up for a half year, most symptoms and lesions of AK and rosacea disappeared with mild hyperpigmentation left. ALA-PDT is commonly recommended for multiple AKs based on effectiveness and noninvasiveness, but has controversial efficacy and safety for rosacea. The unusual excessive inflammation in this patient after ALA-PDT may due to skin barrier destruction, vasomotor dysfunction and the immune response by dead Demodex after PDT. This case indicated that carefully evaluation before ALA-PDT is of great importance, especially for those patients with complicated skin situation. For AKs complicating rosacea, modified parameters of ALA-PDT such as less ALA incubation time or reduced light dose should be further studied to achieve the optimal efficacy and safety of ALA-PDT and offer the best benefit.

Thermo-Mechanical Fractional Injury Enhances Skin Surface- and Epidermis- Protoporphyrin IX Fluorescence: Comparison of 5-Aminolevulinic Acid in Cream and Gel Vehicles.

Thermo-mechanical fractional injury (TMFI) impacts the skin barrier and may increase cutaneous drug uptake. This study investigated the potential of TMFI in combination with 5-aminolevulinic acid (ALA) cream and gel formulations to enhance Protoporphyrin IX (PpIX) fluorescence at the skin surface and in the skin. In healthy volunteers (n = 12) a total of 144 test areas were demarcated on the upper back. Test areas were randomized to (i) TMFI (6 milliseconds, 400 µm at a single pass) or no pretreatment and (ii) 20% ALA in cream or gel formulations. Skin surface PpIX fluorescence was quantified by PpIX fluorescence photography and photometry in 30-minute intervals until 3 hours. PpIX fluorescence microscopy quantified separate PpIX fluorescence in the epidermis, and in superficial-, mid-, and deep- dermis from punch biopsies sampled after 3 hours of ALA incubation. Local skin reactions (LSR) and pain intensities (numerical rating scale 0-10) were evaluated immediately, at 3 hours and 14 days after the intervention. TMFI exposure before photosensitizer application significantly increased skin surface PpIX fluorescence, both for ALA cream (TMFI-ALA-cream 7848 arbitrary units [AU] vs. ALA-cream 5441 AU, 3 hours, P < 0.001) and ALA gel (TMFI + ALA-gel 4591 AU vs. ALA-gel 3723 AU, 3 hours, P < 0.001). The TMFI-mediated increase in PpIX fluorescence was similar for ALA-cream and -gel formulations (P = 0.470) at the skin surface. In the epidermis, PpIX fluorescence intensities increased from combination treatment with TMFI and ALA-cream (TMFI + ALA-cream 421 AU vs. ALA-cream 293 AU, P = 0.034) but not from combination with TMFI and ALA-gel (TMI + ALA-gel 264 AU vs. ALA-gel 261 AU, P = 0.791). Dermal fluorescence intensities (superficial-, mid-, or deep dermis) were unaffected by TMFI pretreatment in both ALA-cream and ALA-gel exposed skin (P = 0.339). ALA-cream generally induced higher PpIX fluorescence intensities than ALA-gel (skin surface P < 0.001 and epidermis P < 0.03). TMFI induced low pain intensities (median 3) and mild LSR that were resolved at 14 days follow-up. Given the present study design, TMFI, in combination with the standardized application of 20% ALA cream and gel formulations, significantly enhanced skin surface PpIX fluorescence compared to no pretreatment. Additionally, TMFI increased epidermal PpIX fluorescence combined with 20% ALA cream vehicle. Thus, TMFI pretreatment and formulation characteristics exert influence on PpIX fluorescence intensities in normal skin. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

621 A novel painless ALA-PDT in the treatment of skin diseases

Pain during conventional photodynamic therapy (C-PDT) is the main limiting adverse effect in its use in dermatology. During the course of C-PDT, most patients experience sensations of burning and tingling pain that vary in intensity. In some cases, patients have to stop the treatment because of unbearable pain. It is generally believed that C-PDT pain is mediated by free radicals generated by PpIX; ROS can either stimulate nerve endings directly or mediate pain through inflammatory by-products. Pain remains the top obstacle that prevents C-PDT application to all patients. Here, we modified C-PDT into a painless PDT treatment (Modified photodynamic therapy , M-PDT, also named novel painless ALA-PDT) by decreasing ALA incubation time and increasing light dose. Our study showed that pain in M-PDT group was significantly reduced in the treatment of actinic keratosis, acne, and condyloma acuminate. Even, in some cases the pain almost vanished. And M-PDT has better efficacy than C-PDT. Further investigation confirmed that M-PDT also inhibit tumor growth on cutaneous squamous cell carcinoma (SCC). Interestingly, compared with C-PDT, M-PDT induced more ROS which should stimulate nerve endings but not. We elucidated a mechanism that the low average amount of ROS may be the reason why M-PDT is painless. Our findings indicate that M-PDT have wide clinical value in skin disease.

Photodynamic inactivation mediated by 5-aminolevulinic acid of bacteria in planktonic and biofilm forms

Bacterial photodynamic inactivation (PDI) employing endogenous production of porphyrins from 5-aminolevulinic acid (ALA) – named ALA-PDI-, is a new promising tool to achieve bacteria control in non-spread infections. The technique combines the action of the porphyrins acting as photosensitisers with light, to produce reactive oxygen species to target the pathogen. To date, some clinical applications of ALA-PDI have been reported although variable responses ranging from total eradication to absence of photokilling were found. ALA-PDI conducted at suboptimal conditions may lead to misleading results and the complexity of haem synthesis in bacteria hinders the optimization of the treatment.The present work aimed to gain insight on the variables affecting ALA-PDI in Gram-positives and Gram-negatives bacteria growing on planktonic and biofilm cultures and to correlate the degree of the response with the amount and type of porphyrin synthesised.Staphylococcus epidermidis and Escherichia coli clinical isolates and Pseudomonas aeruginosa ATCC27853 and Staphylococcus aureus ATCC25923 strains were utilised, and the optimal conditions of concentration and time exposure of ALA, and light dose were set.In both Gram-positive species analysed, a peak of porphyrin synthesis was observed at 1–2 mM ALA in biofilm and planktonic cultures, which fairly correlated with the decrease in the number of CFU after PDI (5 to 7 logs) and porphyrin content was in the same order of magnitude. In addition, ALA-PDI was similarly effective for planktonic and biofilm S. aureus cultures, and more effective in S. epidermidis planktonic cultures at low light doses. Beyond a certain light dose, it was not possible to achieve further photosensitization. Similarly, a plateau of cell death was attained at a certain ALA incubation time. Accumulation of hydrophilic porphyrins at longer incubation periods was observed.The proportion of porphyrins changed as a function of ALA concentration and incubation time in the Gram-positive bacteria, though we did not find a clear correlation between the porphyrin type and PDI response. As a salient feature was the presence of isococroporphyrin isoforms in both Gram-positive and Gram-negative bacteria.Gram-negative bacteria were quite refractory to the treatment: P. aeruginosa was slightly inactivated (4-logs reduction) at 40 mM ALA, whereas E. coli was not inactivated at all. These species accumulated high ALA quantities and the amount of porphyrins did not correlate with the degree of photoinactivation. Our microscopy studies show that porphyrins are not located in the envelopes of Gram-negative bacteria, reinforcing the hypothesis that endogenous porphyrins fail to attack these structures.

Photodynamic therapy for cutaneous squamous cell carcinoma in situ: Impact of anatomic location, tumor diameter, and incubation time on effectiveness

Photodynamic therapy (PDT) has been reported as a treatment for cutaneous squamous cell carcinoma in situ (SCCis), but only limited data are available on the effectiveness of PDT with aminolevulinic acid (ALA-PDT). To review the outcomes of SCCis treated with ALA-PDT and examine factors associated with response. A retrospective review identified 58 patients with 68 primary SCCis lesions treated with ALA-PDT and blue light illumination. Patient demographics, lesion features, treatment details, clinical response, and subsequent recurrence were extracted from medical record reviews. On completion of PDT the initial complete response rate was 77.9% and was not associated with the number of PDT treatments. On multivariate analysis factors associated with response were location on the face, tumor diameter <2cm, and longer ALA incubation time. Lesions treated with a maximum incubation time of <3hours had a 53.3% response compared with 84.9% for longer incubation. Subsequent recurrence of SCCis was noted in 7 of 53 cases (13.2%) at a median time of 11.7months. This was a retrospective study performed at a single institution without systematic follow-up. ALA-PDT may be an effective treatment for selected cases of SCCis. Effectiveness is impacted by anatomic location, tumor diameter, and ALA incubation time.

Early α-linolenic acid exposure to embryo reduces pentylenetetrazol-induced seizures in zebrafish larva

Over the past few years, there has been a tremendous increase in interest of general population toward food-based therapies for management of chronic clinical conditions due to their lesser adverse effects with prolonged use over pharmacotherapies. Foods enriched with omega-3 fatty acids have shown some promising results in case of epilepsy. The present study was envisioned to investigate the effect of early exposure of α-linolenic acid (ALA), an essential omega-3 fatty acid in developing zebrafish (Danio rerio) embryos toward pentylenetetrazol (PTZ)-induced seizure susceptibility. The healthy wild-type zebrafish embryos were incubated in system water or system water containing different ALA concentrations (1–20 µM) till 7 dpf (days post fertilization). Each larva at 7 dpf was placed in 8 mM PTZ solution and seizure event was recorded. ALA incubation at 10 µM and 20 µM concentrations showed a dose-dependent reduction in PTZ-mediated hyperactive responses in larvae indicated by a marked decrease in total distance travelled and speed, as compared to vehicle control. Furthermore, both the treated groups showed increase in the latency to PTZ-induced clonus-like seizures in larvae, as compared to vehicle control. ALA incubated larvae at 10 µM and 20 µM concentrations also showed a significant reduction in c-fos mRNA level. A marked increase in the level of ALA and docosahexaenoic acid was also observed in the larvae incubated at highest effective concentration of ALA. The present study concluded that embryonic exposure of ALA reduced PTZ-induced seizures in zebrafish larva.

Optimization and therapeutic effects of PDT mediated by ALA and MAL in the treatment of cutaneous malignant lesions: A comparative study.

5-aminolevulinic acid (ALA) and its methylated ester (MAL) are the most common topical agents used in photodynamic therapy (PDT) as precursors of the photosensitizer protoporphyrin IX (PpIX). The induction of newly PpIX depends on incubation time of each photosensitizer in the tissue and the presence of high intralesional porphyrin levels is an important parameter for the PDT effectiveness. This study used laser-induced fluorescence (LIF) spectroscopy to evaluate the optimum time to light exposure of PDT mediated by ALA (20% w/w) and MAL (10% w/w) to treat malignant lesions precursors of cutaneous squamous cell carcinoma induced in mice. The therapeutic effects obtained by optimized ALA- and MAL-PDT were assessed 10 and 20 days after treatments. Higher PpIX levels were evidenced in the lesions photosensitized by ALA than MAL and according to LIF measurements the PDT irradiation was performed, respectively, at 300 and 330 minutes after ALA and MAL incubation. Histopathological analysis evidenced necrosis and epithelial atrophy after 10 days of PDT using both prodrugs, as well as reepitelization and collagen deposition at 20 days. Thus, despite the distinct concentration of ALA and MAL used in the formulation of each photosensitizing cream, PDT mediated by both photosensitizing agents obtained similar therapeutic outcomes.

Aminolevulinic Acid-Mediated Photodynamic Therapy Causes Cell Death in MG-63 Human Osteosarcoma Cells.

The aim of this study was to test the efficacy of aminolevulinic acid-mediated photodynamic therapy (PDT) against the human osteosarcoma cell line MG-63. Osteosarcoma is the most common type of primary malignant bone tumor diagnosed in the United States among adolescents and children. Treatments for osteosarcoma often result in diminished limb use or amputation. Because ALA-mediated PDT exhibits dual specificity in the context of tumor killing, this therapy could represent a less invasive, but effective, treatment for this disease. To assess ALA dark toxicity in MG-63 cells, cells were incubated with varying concentrations of ALA, and cell viability was determined by crystal violet assay. Protoporphyrin IX (PpIX) accumulation was assessed subsequent to ALA incubation at various concentrations using spectrofluorometry. Cell death subsequent to ALA-PDT was determined by illuminating cells at a wavelength of 635 nm at various light intensities subsequent to ALA incubation. Cell viability was assessed using the MTT assay. ALA dark toxicity was observed only at the highest concentrations of 2, 5, and 10 mM. Maximal PpIX concentration was observed at 0.5 and 1 mM ALA, subsequent to a 24-h incubation. Maximal cell death with minimal light toxicity was observed at 0.5 and 1 mM ALA after illumination with 0.6 and 3 J/cm(2) light. Collectively, our data indicate that ALA-PDT can result in the death of MG-64 human osteosarcoma cells in vitro.

ALA-PDT elicits oxidative damage and apoptosis in UVB-induced premature senescence of human skin fibroblasts

Background5-Aminolevulinic acid photodynamic therapy (ALA-PDT) has been used for the treatment of skin photoaging. It can significantly improve the appearance of fine lines, dotted pigmentation, and roughness of photoaged skin. However, the mechanisms by which ALA-PDT yields rejuvenating effects on photoaged skin have not been well elucidated. Thus, in this study we explored the effects of ALA-PDT in photoaged fibroblasts. MethodsWe established a stress-induced premature senescence (SIPS) model by repeated exposures of human dermal fibroblasts (HDFs) to ultraviolet B (UVB) irradiation. Cells were irradiated by red light laser at 635nm wavelength (50mW/cm2). Intracellular protoporphyrin IX (PpIX) was detected by confocal microscopy. Intracellular reactive oxygen species (ROS) level and mitochondrial membrane potential (MMP) change were detected by fluorescence microscopy and flow cytometry. Morphological changes were observed by optical microscopy. Proliferative activity was measured by a cell counting kit-8 (CCK-8). Cell apoptosis was detected by fluorescence microscopy using Hoechst staining and flow cytometry using annexin V/propidium Iodide double staining. ResultsIntracellular PpIX fluorescence in UVB-induced premature senescent HDFs (UVB-SIPS-HDFs) reached the highest intensity after incubation with 1.00mmol/L ALA for 6h (P<0.05). Compared with control group, intracellular ROS level, MMP, and apoptotic rate were increased (P<0.05) and proliferative activity was decreased (P<0.05) in UVB-SIPS-HDFs treated with ALA-PDT, which were positively correlated to ALA incubation time and red light laser dose. ConclusionOur study demonstrated that ALA-PDT elicits oxidative damage and apoptosis in photoaged fibroblasts in vitro, which may be the basis for the rejuvenating effects on photoaged skin.

Temperature-Modulated Photodynamic Therapy for the Treatment of Actinic Keratosis on the Extremities: A One-Year Follow-up Study.

The efficacy of photodynamic therapy (PDT) using topical 5-aminolevulinic acid (ALA) for the treatment of actinic keratosis (AK) is lower on the distal extremities compared with head and neck areas. A recent pilot study demonstrated increased efficacy of ALA PDT when the skin is warmed during ALA incubation. Prolonged clearance rates on the heated extremity were noted in 3 subjects that were evaluated after the study ended. The aim of this study was to evaluate the longevity of clearance rates after temperature-modulated PDT for the treatment of AKs on the extremities. A total of 18 subjects (20 pairs of extremities) with at least 10 AKs on the upper or lower extremities were enrolled in the single-center study. Twenty percent ALA was applied to both extremities and heated during the 1-hour incubation period, followed by exposure to 10 J/cm 417-nm blue light. Lesions were photographed, counted, and templated at baseline, 1 week, and 3, 6, 9, and 12 months after treatment. A total of 17 subjects completed the 1-year study. The total number of lesions counted at baseline was 724 Grade 1 and 2 AKs (median 15 on each extremity). The lesion count at 3 and 12 months was 70 (9.6%) and 72 (9.9%), respectively. Grade 3 AKs did not resolve with treatment. The median baseline temperature of the treated extremities was 31.6°C. The median maximum temperature during the 1-hour incubation period was 41.2°C. The median clearance at 3 months was 90% and the same was maintained at 12 months. No new AK lesions formed in the treated areas within the 12-month follow-up period. Warming the skin after application of ALA is well tolerated, does not increase side effects, and increases the long-term efficacy of PDT for the treatment of AKs. The authors suggest that mild skin warming may both improve efficacy and reduce variability of response to PDT in practice.

Nonablative fractional laser as a tool to facilitate skin penetration of 5-aminolaevulinic acid with minimal skin disruption: a preliminary study

Effective penetration of a photosensitizer is an essential step in photodynamic therapy (PDT). There have been trials of several methods, including laser treatment, to facilitate prompt and sufficiently deep transdermal drug delivery. To evaluate the effects of nonablative fractional laser pretreatment on 5-aminolaevulinic acid (ALA) penetration of the skin. Twelve treatment areas (1 × 1 cm(2)) on the backs of 10 healthy male subjects were mapped. Test areas received laser treatment followed by incubation with ALA. Laser treatment was performed with a 1550 nm fractional erbium glass laser, and the laser energy was set to 20 or 50 mJ with a spot density of 50 cm(-2). ALA incubation time was 30, 60 or 180 min. Porphyrin fluorescence was measured. Sites pretreated with nonablative fractional laser showed significantly increased porphyrin fluorescence compared with nonpretreated areas. Laser energy strength and ALA incubation time were positively correlated with ALA absorption. Nonablative fractional laser treatment effectively enhanced ALA skin penetration. Pretreatment with a nonablative fractional laser can be used for ALA-PDT to achieve higher ALA uptake and shortened ALA incubation times with minimal skin barrier disruption compared with ablative laser.

Enhancing the effect of 5-aminolevulinic acid based photodynamic therapy in human meningioma cells

The interest in photodynamic therapy (PDT) in cancer treatment has continuously increased since its' advent in the 1960s. In neurosurgery, 5-aminolevulinic acid based photodynamic therapy (5-ALA PDT) is used for malignant glioma in vitro and in vivo. Data about PDT in meningioma, which is the second most frequent primary brain tumor, is sparse. Preliminary work indicated that meningiomas are more resistant to PDT than gliomas. In the present study we evaluated whether the effect of 5-ALA PDT on malignant meningioma cells can be increased by ciprofloxacin and changes in incubation time, factors known to influence the effectiveness of PDT in other tumor entities. An in vitro-PDT model of a malignant human meningioma cell line (KT21-MG) was chosen as screening method. Cultured cells were incubated with varying 5-ALA concentrations for 4h and exposed to PDT (control group). Two experimental groups, one with 5-ALA and ciprofloxacin (group I) and one with 24-h ALA incubation time (group II), were studied, respectively. Cell viability was assessed by WST-1 assay. Ciprofloxacin and longer ALA incubation time significantly increased the lethal effect of 5-ALA PDT on meningioma cells. Efficacy of 5-ALA PDT could be increased by adjunction of ciprofloxacin in conventional clinical dosing and by prolongation of ALA incubation time. As ciprofloxacin is a common antibiotic with good tissue penetration, low toxicity and a favorable risk profile it represents a clinically interesting method for future PDT trials in meningiomas.

Targeting tumour energy metabolism potentiates the cytotoxicity of 5-aminolevulinic acid photodynamic therapy

Background:Cancerous cells usually exhibit increased aerobic glycolysis, compared with normal tissue (the Warburg effect), making this pathway an attractive therapeutic target.Methods:Cell viability, cell number, clonogenic assay, reactive oxygen (ROS), ATP, and apoptosis were assayed in MCF-7 tumour cells and corresponding primary human mammary epithelial cells (HMEC).Results:Combining the glycolysis inhibitors 2-deoxyglucose (2DG; 180 mM) or lonidamine (300 μM) with 10 J cm−2 5-aminolevulinic acid (ALA) photodynamic therapy (PDT) increases MCF-7 cytotoxicity (by 3.5-fold to 70% death after 24 h, and by 10-fold in 9-day clonogenic assays). However, glycolysis inhibition only slightly increases HMEC PDT cytotoxicity (between two-fold and three-fold to a maximum of 9% death after 24 h). The potentiation of PDT cytotoxicity only occurred if the glycolysis inhibitors were added after ALA incubation, as they inhibited intracellular accumulation of photosensitiser if coincubated with ALA.Conclusion:As 2DG and lonidamine are already used as cancer chemotherapeutic agents, our results are directly translatable to combination therapies with existing topical PDT.

Photodynamic Therapy as Palliative Therapy for Invasive Syringoid Eccrine Carcinoma of the Auricle: A Case Report

Recurrent eccrine syringomatous carcinoma is an extremely rare adnexal tumor predominantly found in the head and neck region. We present a case of a 75-year-old woman with a 7-year history of recurrent syringoid eccrine carcinoma in the scalp and auricle. She had undergone five previous oncologic resections and declined further oncologic ablation of the auricle, including temporal bone and external ear canal resection. We performed five sessions of palliative photodynamic therapy using topical aminolevulinic acid HCL 20% (ALA) and between 25 and 33 pulses of Intense Pulsed Light (Quantum) with an intensity of 30 Joules. The ALA incubation time was 3 hours, while the time between each session was 4 weeks. This treatment helped to control ulceration, pain, and swelling. We saw the patient 1 month after the last treatment, by that time she moved and we lost contact.

Prospective Study of Topical 5-Aminolevulinic Acid Photodynamic Therapy for the Treatment of Moderate to Severe Acne Vulgaris in Chinese Patients

Topical photodynamic therapy (PDT) mediated with 5-aminolevulinic acid (ALA) offers an alternative option for the treatment of acne vulgaris. To study the effects of ALA dose, incubation time, and lesion type on protoporphyrin IX (PpIX) production and treatment outcomes. To examine the time course of PpIX production, 10% ALA was applied to inflammatory papules for 1 to 5 hours and followed by in situ fluorescence examination. To determine the effects of ALA dose and lesion type, 3, 5, and 10% ALA was applied to acne lesions in split-face fashion for 3 hours followed by whole-face light irradiation at 633 nm and 30 to 70 J/cm2. Treatment was repeated twice at 2-week intervals. PpIX reached a stable level after 3 hours of incubation. Similar PpIX levels were seen in areas receiving 3, 5, and 10% ALA. Poisson regression analyses indicated that lesion counts decreased by 0.791 times for a one-unit increase in treatment times (95% CI 0.782-0.799 < .0001) but only by 0.999 times for a one-unit increase in ALA dose (95% CI 0.998-1.000 = .22). The combination of low-dose ALA and a red light is a safe and effective option for the treatment of moderate to severe acne.

Targeting of sebaceous glands by δ‐aminolevulinic acid‐based photodynamic therapy: An in vivo study

Wide application of ALA-PDT for acne is limited due to relative strong side effects, such as pain and erythema. The objective of this study was to establish a protocol for ALA-PDT that would provide specific destruction of sebaceous glands at the lowest concentrations and shortest contact times of ALA. The rhino (hr(rh) hr(rh) ) murine model, an experimental acne model, was used in this study. A freshly prepared hydrophilic ALA hydrochloride ointment (2.5%, 5%, and 20%) was applied to the backs of 16-week-old male rhino mice. The fluorescence intensity (FI) of ALA-induced protoporphyrin IX (ALA-PpIX) on the skin was measured by spectrofluorometry. Skin samples were taken at 1, 2, and 4 hours after ALA application to determine the tissue distribution of ALA-PpIX by fluorescence microscopy. Light irradiation was also performed with a broadband light source (600-1100 nm, 15 J/cm² , 60 mW/cm²) with subsequent histological examination 1 day after treatment. Prominent increases of ALA-PpIX were observed 1 hour after application of 5% and 20% ALA, while no increase was observed with 2.5% ALA until 2 hours. A direct correlation was found between ALA concentration and ALA-PpIX FI. While no fluorescence was detected 1 hour after application of 2.5% or 5% ALA, 20% ALA produced a strong fluorescence in the epidermis, utricle walls, and sebaceous glands. Histological evaluation showed no damage to skin treated with 2.5% ALA-PDT incubated for 1 hour. Damage was still focused within the sebaceous glands with longer incubation times. Increased ALA concentrations resulted in more prominent damage to the epidermis and sebaceous glands, with deeper damage to the dermis when longer incubation times were used. Focused damage of sebaceous glands can be achieved with ALA-PDT when low concentrations of ALA (2.5-5.0%) and short incubation times (to 2 hours) were used.

Pathological Role of Aminolevulinate in Uremic Patients

Previous reports have demonstrated that δ-aminolevulinate (ALA) can promote iron release from horse spleen ferritin under conditions of high serum ALA levels in uremia; therefore, we speculated that the accumulated ALA in uremic patients would stimulate iron release from ferritin, resulting in accelerated oxidative stress and uremic complications. We measured the plasma ALA of uremic patients and examined the ALA-induced iron release from human ferritin. The participants consisted of 30 hemodialysis patients and 14 healthy subjects. Plasma malondialdehyde was measured as a surrogate marker of lipid peroxidation. The plasma exchange effluent from two patients who had undergone plasma exchange (for the treatment of systemic lupus erythematosus and acute myeloblastic leukemia) was collected and treated to obtain the human ferritin-rich fraction. Iron release from ferritin was examined using bathophenanthroline sulfate. The influence of antioxidants and different pH levels on iron release were investigated. Plasma ALA and malondialdehyde concentration in the hemodialysis patient was significantly higher than that in healthy subjects. ALA was positively correlated with malondialdehyde. The abundance of iron release was dependent on the ALA concentration and incubation time. Iron release at the high pH of 7.6 was decreased compared with that at pH 7.4. Citrate increased iron release at pH 7.4, but citrate-stimulated iron release was totally abolished at pH 7.6. Our study suggests that ALA accumulation may have a role to play in certain complications in uremic patients, such as oxidative stress, by releasing iron from ferritin.