A pectin-based photoactivated bactericide nanosystem for achieving an improved utilization rate, photostability and targeted delivery of hematoporphyrin.

Photoactivated pesticides have many advantages, such as high activity, low toxicity, and no drug resistance. However, poor photostability and a low utilization rate limit their practical application. Herein, the photosensitizer hematoporphyrin (HP) was used as a photoactivated pesticide, covalently linked with pectin (PEC) via ester bonds, to prepare an amphiphilic polymer pro-bactericide, and subsequently self-assembled in aqueous solutions to obtain an esterase-triggered nanobactericide delivery system. The fluorescence quenching effect due to the aggregation of HP in nanoparticles (NPs) enabled the inhibition of photodegradation of HP in this system. Esterase stimulation could trigger HP release and increase its photodynamic activity. Antibacterial assays have shown that the NPs had potent antibacterial capacity, almost completely inactivating bacteria after 60 min of exposure to light. The NPs had good adherence to the leaves. Safety assessment indicated that the NPs have no obvious toxic effects on plants. Antibacterial studies on plants have shown that the NPs have excellent antibacterial effects on infected plants. These results provide a new strategy for obtaining a photoactivated bactericide nanosystem with a high utilization rate and good photostability and targeting ability.

Nanoscale Hf-hematoporphyrin frameworks for synergetic sonodynamic/radiation therapy of deep-seated tumors.

Most of tumors are located in deep-depth of animals, and the therapy of deep-seated tumors remains a severe challenge due to the performance reduction of promising technologies including phototherapy. To solve the problem, herein we have developed a hafnium-hemoporfin frameworks (HfHFs) as multifunctional theranostic nanoplatforms for synergetic sonodynamic therapy (SDT) and radiation therapy (RT) of deep-seated tumors. HfHFs are constructed by a sonication-assisted assembly route with hematoporphyrin monomethyl ether (HMME) sonosensitizer molecules as bridging linkers and Hf4+ as metal nodes. The resulting HfHFs sample is composed of spherical nanoparticles with size of 90-130 nm, and then surface-modified with DSPE-PEG to improve the water-dispersity. Under ultrasound (US) irradiation, HMME ligands in HfHFs can be motivated to produce singlet oxygen (1O2) due to sonodynamic effect. When the HfHFs sample is exposed by X-ray, the high atomic-number Hf4+ in the HfHFs can effectively absorb X-ray to increase RT effect by producing hydroxyl radicals (•OH). When HfHFs dispersion is intravenously injected in the tumor-bearing mice, the tumor can be monitored by CT imaging. Moreover, the deep-seated tumors coated by tissue barriers can be suppressed effectively by the synergistic SDT and RT, which is better than that of SDT or RT alone. Therefore, HfHFs can be employed as a novel nanoagent for the SDT-RT of deep-seated tumors.

Hematoporphyrin monomethyl ether photodynamic therapy for the treatment of facial port-wine stains resistant to pulsed dye laser.

BACKGROUND: Pulsed dye laser is the first treatment choice for port-wine stains. However, as some facial port-wine stains are resistant to this modality, we evaluated the efficacy and safety of hematoporphyrin monomethyl ether (hemoporfin) photodynamic therapy for the treatment of such resistant port-wine stains. METHODS: Patients were treated with two sessions of hemoporfin photodynamic therapy in our department. Patients received an intravenous injection of hematoporphyrin monomethyl ether (5 mg/kg) followed by 532 nm LED green light therapy. Three physicians graded the improvement in the port-wine stain, using a 4-level scale. Patients' satisfaction, reaction to treatment, and adverse effects were evaluated. RESULTS: Thirty-one patients (mean age, 23.9 ± 11.9 years, range, 3-48 years) were enrolled in this study. Hypertrophic lesions accounted for 48.4% of port-wine stain, with 80.6% of lesions being larger than 40 cm2. With regard to location, 41.9% were located on the central face and 32.3% involved a mix of the central and peripheral face. After one session, a treatment response was identified in 87.1% of cases, with the response deemed 'significant' in 29.0%. After two sessions, these rates increased to 100.0% and 61.3%, respectively. The clinical effect after two sessions was significantly greater than that after one session. Treatment reactions and adverse effects were well tolerated, and included pruritus, burning sensation, pain, edema, purpura-like change, blister, crust, and hyperpigmentation. CONCLUSIONS: Hemoporfin photodynamic therapy is a promising treatment for port-wine stains resistant to pulsed dye laser therapy.

Effect of 532nm photodynamic therapy with hemoporfin on the expression of vascular endothelial growth factor in cultured human vascular endothelial cells.

BACKGROUND: Photodynamic therapy (PDT) with hemoporfin (hematoporphyrinmonomethyl ether, HMME) and 532 nm continuous-wave lasers is effective for port-wine stains (PWS) and is considered as a promising treatment modality. The vascular endothelial growth factor (VEGF) is involved in the development of PWS. This study aimed to investigate the effect of 532 nm-HMME-PDT on the in vitro expression of VEGF in human umbilical vein endothelial cells (HUVECs) exposed to different power levels of 532 nm laser and different concentrations of HMME. METHOD: The CCK-8 assay was performed to assess cell viability. Enzyme-linked immunosorbent assay (ELISA) was performed to measure VEGF secretion. VEGF and VEGF receptor (VEGFR) mRNA expression levels were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: Within 72 h after HMME-PDT, cell viability was inhibited, secretion and expression of VEGF was decreased, and expression of VEGFR mRNA was significantly decreased with the increase of HMME concentration. CONCLUSION: 532 nm-HMME-PDT can downregulate the expression of VEGF and VEGFR mRNA. Future studies are necessary to examine the HMME doses to achieve better efficacy with fewer adverse effects.

Retrospective study of photodynamic therapy for pulsed dye laser-resistant port-wine stains.

Pulsed dye laser-resistant port-wine stains present a therapeutic challenge. The aim of this study was to evaluate the efficacy and safety of photodynamic therapy for treating these lesions. A total of 67 patients with pulsed dye laser-resistant cervicofacial port-wine stains were retrospectively assessed after undergoing photodynamic therapy mediated with a combination of hemoporfin and 532-nm light. For objective evaluation of photodynamic therapy efficacy, first, the colorimetric changes in the port-wine stain lesions were evaluated according to the L*a*b* color coordinate system, then the values of color changes (ΔE) and blanching rate were calculated. For subjective evaluation of improvement, photographs taken before and after photodynamic therapy were evaluated by three independent assessors blindly. Patient satisfaction was also used as a factor in the subjective evaluation. Adverse events were recorded after treatment. The median ΔE decreased significantly from the pretreatment value of 13.42 to 9.90 at the 2-month follow up (P < 0.001). The median blanching rate of port-wine stains was 28.04% after an average of 1.21 sessions of photodynamic therapy. Based on the overall visual assessment, 46.2% patients showed excellent or good levels of improvement (>50% color blanching). Adverse events were minimal, transient and self-limiting. In conclusion, photodynamic therapy serves as an alternative means to treat pulsed dye laser-resistant port-wine stains.

Yolk-structured multifunctional up-conversion nanoparticles for synergistic photodynamic-sonodynamic antibacterial resistance therapy.

The worldwide increase in bacterial antibiotic resistance has led to a search for alternative antibacterial therapies. The present study reports the development of yolk-structured multifunctional up-conversion nanoparticles (UCNPs) that combine photodynamic and sonodynamic therapy for effective killing of antibiotic-resistant bacteria. The multifunctional nanoparticles (NPs) were achieved by enclosing hematoporphyrin monomethyl ether (HMME) into its yolk-structured up-conversion core and covalently linked rose bengal (RB) on its silica (SiO2) shell. Excitation of UCNPs with near-infrared (NIR) light that has improved penetration depth for photodynamic therapy (PDT) enabled the activation of HMME and RB and thus the generation of singlet oxygen (1O2). The SiO2 layer, which improved the biocompatibility of the UCNPs, surrounded the yolk structure, with a cavity space which had a high efficiency of loading photosensitizers. Synergistic PDT and sonodynamic therapy (SDT) improved the photosensitizer utilization rate. As a result, a greater inhibition rate was observed when antibiotic-resistant bacteria were treated with a combined therapy (100%) compared with either the PDT (74.2%) or SDT (70%) alone. Our data indicate that the multifunctional NPs developed in this study have the potential for use in the clinical synergistic PDT-SDT treatment of infectious diseases caused by antibiotic-resistant bacteria.

Evaluation of Antimicrobial Photodynamic Therapy against Streptococcus mutans Biofilm in situ.

AIM: This study investigated the effect of antimicrobial photo-dynamic therapy (aPDT) over Streptococcus mutans biofilm. MATERIALS AND METHODS: Eighteen (n = 18) patients were selected and one palatine device with dental blocks was used. The biofilm was treated by curcumin and Photogem® with a LED and the effect was analyzed by CFU/ml. RESULTS: Although, statistical analysis showed significant reductions for aPDT mainly with Photogem® (p = 0.02), these were low. CONCLUSION: The results suggest a low antimicrobial effect of aPDT over S. mutans biofilm. Some parameters used need to be improved. CLINICAL SIGNIFICANCE: This technique can be a promising in Dentistry.

Hemoporfin Photodynamic Therapy for Port-Wine Stain: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Photodynamic therapy (PDT) has shown potentially beneficial results in treating port-wine stain, but its benefit-risk profile remains undefined. This study aimed to evaluate the efficacy and safety of PDT conducted with hemoporfin and a 532 nm continuous wave laser to treat port-wine stain clinically. PATIENTS AND METHODS: This randomized clinical trial was conducted in eight hospitals in China. Participants were adolescent and adult patients (age range: 14-65 years old) with port-wine stain. During stage 1 (day 1 to week 8) all patients were randomized at a 3:1 ratio to treatment (532 nm laser irradiation (96-120 J/cm2) with hemoporfin (5mg/kg; PDT-hemoporfin, n = 330)) or placebo groups (irradiation with placebo (PDT-placebo, n = 110)); during stage 2 (week 8 to 16) patients in both groups were offered treatment. Clinician-evaluators, who were blind to the study, classified each case on the following four-level scale according to assessment of before and after standardized pictures of the lesion area: no improvement: <20%; some improvement: 20-59%; great improvement: 60-89%; or nearly completely resolved: ≥90%. The primary efficacy endpoint was proportion of patients achieving at least some improvement at week 8. The secondary efficacy endpoints were proportion of patients achieving nearly completely resolved or at least great improvement at week 8, proportion of patients achieving early completely resolved, at least great improvement, or at least some improvement at week 16, and the corresponding satisfaction of the investigators and the patients (designated as 'excellent', 'good', 'moderate', or 'ineffective') at weeks 8 and 16. RESULTS: Compared to the PDT-placebo group, the PDT-hemoporfin group showed a significantly higher proportion of patients that achieved at least some improvement (89.7% [n = 295; 95% CI, 85.9%-92.5%] vs. 24.5% [n = 27; 95% CI, 17.4%-33.3%]) at week 8 (P < 0.0001) and higher improvements for all secondary efficacy endpoints. Treatment reactions occurred in 99.5% (n = 731; 95% CI, 98.7%-99.8%) of the PDT-hemoporfin treatments (n = 735). Hyperpigmentation occurred in 22.9 per 100 patient-treatments (n = 168; 95% CI, 20.0-26.0) in the PDT-hemoporfin treated patients. CONCLUSIONS: Hemoporfin-mediated PDT is an effective and safe treatment option for adolescent and adult patients with port-wine stain. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-TRC-08000213.

A multi-functional nanoplatform for tumor synergistic phototherapy.

Phototherapy, which mainly includes photothermal treatment (PTT) and photodynamic treatment (PDT), is a photo-initiated, noninvasive and effective approach for cancer treatment. The high accumulation of photosensitizers (PSs) in a targeted tumor is still a major challenge for efficient light conversion, to generate reactive oxygen species (ROS) and local hyperthermia. In this study, a simple and efficient hyaluronic acid (HA)-modified nanoplatform (HA-TiO2@MWCNTs) with high tumor-targeting ability, excellent phototherapy efficiency, low light-associated side effects and good water solubility was developed. It could be an effective carrier to load hematoporphyrin monomethyl ether (HMME), owing to the tubular conjugate structure. Apart from this, the as-prepared TiO2@MWCNTs nanocomposites could also be used as PSs for tumor PTT and PDT. Those results in vitro and in vivo showed that the anti-tumor effect of this system-mediated PTT/PDT were significantly better than those of single treatment manner. In addition, this drug delivery system could realize high ratio of drug loading, sustained drug release, prolonged circulation in vivo and active targeted accumulation in tumor. These results suggest that HA-TiO2@MWCNTs/HMME has high potential for tumor synergistic phototherapy as a smart theranostic nanoplatform.

Calcium overload and in vitro apoptosis of the C6 glioma cells mediated by sonodynamic therapy (hematoporphyrin monomethyl ether and ultrasound).

UNLABELLED: The objective of this study was to investigate the role of intracellular calcium overload in the in vitro apoptosis of C6 glioma cells mediated by low level ultrasound and hematoporphyrin monomethyl ether (HMME) therapy. The frequency of ultrasound was optimized by the cell viability assay using 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The apoptotic rate, reactive oxygen species (ROS) and decreased mitochondrial membrane potential (MMP) were determined by flow cytometry. Morphological changes were observed by the transmission electron microscope. Concentrations of intracellular Ca2+, [Ca2+]i were detected by a confocal microscopic laser scanning, and the release of cytochrome-c (cyt-c) was measured by western blotting. RESULTS: The SDT-mediated apoptotic effect involved an overload of [Ca2+]i derived from the intra- and extracellular sources during the early progression of apoptotosis. The process was associated with an increased ROS production, a decreased MMP, and a release of cyt-c. In conclusion,the combined use of low level ultrasound and HMME improved the apoptotic rate of C6 glioma cells mediated by ultrasound alone. The [Ca2+]i overload involving activation of mitochondrial signaling played a pivotal role in the SDT-induced apoptosis.

Comparison of pulsed dye laser (PDL) and photodynamic therapy (PDT) for treatment of facial port-wine stain (PWS) birthmarks in pediatric patients.

BACKGROUND: Vascular-acting photodynamic therapy (PDT) might be an alternative approach for treating port wine stain (PWS) birthmarks, but the usefulness of PDT for pediatric patients has not been fully investigated. STUDY DESIGN: Medical records of pediatric patients (3-10 years old) with red and purple facial PWS were analyzed. Clinical outcomes after one session of PDL (585 nm, 4.8-6.5 J/cm(2)) and PDT (Hemoporfin - 3.5mg/kg, copper vapour laser - 120 J/cm(2)) were compared. RESULTS: The rate of excellent response in PDT group was significantly higher than that in PDL group (25.0% vs 10.9%). For red lesions there was no significant difference in overall response between PDL and PDT group, but for purple lesions the overall response rate of PDT group was significantly higher than that of PDL group (93.0% vs 75.6%). Lesions located at the forehead, cheek and jaw regions showed better responses to PDT. Incidences of pigmentation and scar formation in PDT group were significantly lower than PDL group (8.3% vs 21.1%). CONCLUSION: This study suggests that PDT is safe and effective for treating facial PWS of childhood patients.

Azide quenching of singlet oxygen in suspensions of microenvironments of neutral and surface charged liposomes and micelles.

The azide anion is often used as a physical quencher of singlet oxygen, the important active intermediate in photosensitized oxidation. An observed effect of azide on the rate of a reaction is considered an indication to the involvement of singlet oxygen. In most biological photosensitizations, the light-absorbing sensitizer is located in a membrane or in an intracellular organelle, whereas azide is water soluble. The quenching it causes relies on a physical encounter with singlet oxygen during the latter's short lifetime. This can happen either if azide penetrates into the membrane's lipid phase or if singlet oxygen is intercepted when diffusing in the aqueous phase. We demonstrate in this article the difference, in liposomes' suspension, between the effect of azide when using a water-soluble and membrane-bound chemical targets of singlet oxygen, whereas this difference does not exist when micelles are used. We explain the difference on the population of sensitizer and target in the liposome vs micelle. We also show the effect that exists on azide quenching of singlet oxygen by electrically charged lipids in liposomes. This is a result of the accumulation or dilution of azide in the debye layer near the membranes' surface, due to the surface Gouy-Chapman potential.

Side-by-side comparison of photodynamic therapy and pulsed-dye laser treatment of port-wine stain birthmarks.

BACKGROUND: Pulsed-dye laser (PDL)-mediated photothermolysis is the current standard treatment for port-wine stain (PWS) birthmarks. Vascular-targeted photodynamic therapy (PDT) might be an alternative for the treatment of PWS. OBJECTIVES: To compare clinical outcomes of PDT and PDL treatment of PWS. METHODS: Two adjacent flat areas of PWS lesions were selected from each of 15 patients (two male and 13 female; age 11-36 years) and randomly assigned to either single-session PDL or PDT. PDL was delivered using a 585-nm pulsed laser. PDT was carried out with a combination of haematoporphyrin monomethyl ether (HMME) and a low-power copper vapour laser (510.6 and 578.2 nm). Clinical outcomes were evaluated colorimetrically and visually during follow-up. RESULTS: A total of nine red PWS lesions and six purple PWS lesions were treated. For red PWS, colorimetric assessment showed that the blanching rates of PDL and PDT at 2 months ranged from -11% to 24% and 22% to 55%, respectively. For purple PWS, blanching rates of PDL and PDT ranged from 8% to 33% and 30% to 45%, respectively. Overall, there was a significant difference between the blanching effect of single-session PDL treatment and a single-session PDT treatment. CONCLUSIONS: This side-by-side comparison demonstrates that PDT is at least as effective as PDL and, in some cases, superior. The true value of PDT for the treatment of PWS deserves further investigation.

Crystal structure of two anti-porphyrin antibodies with peroxidase activity.

We report the crystal structures at 2.05 and 2.45 Å resolution of two antibodies, 13G10 and 14H7, directed against an iron(III)-αααß-carboxyphenylporphyrin, which display some peroxidase activity. Although these two antibodies differ by only one amino acid in their variable λ-light chain and display 86% sequence identity in their variable heavy chain, their complementary determining regions (CDR) CDRH1 and CDRH3 adopt very different conformations. The presence of Met or Leu residues at positions preceding residue H101 in CDRH3 in 13G10 and 14H7, respectively, yields to shallow combining sites pockets with different shapes that are mainly hydrophobic. The hapten and other carboxyphenyl-derivatized iron(III)-porphyrins have been modeled in the active sites of both antibodies using protein ligand docking with the program GOLD. The hapten is maintained in the antibody pockets of 13G10 and 14H7 by a strong network of hydrogen bonds with two or three carboxylates of the carboxyphenyl substituents of the porphyrin, respectively, as well as numerous stacking and van der Waals interactions with the very hydrophobic CDRH3. However, no amino acid residue was found to chelate the iron. Modeling also allows us to rationalize the recognition of alternative porphyrinic cofactors by the 13G10 and 14H7 antibodies and the effect of imidazole binding on the peroxidase activity of the 13G10/porphyrin complexes.

Adverse effects associated with photodynamic therapy (PDT) of port-wine stain (PWS) birthmarks.

BACKGROUND: Several Chinese studies suggest that Hemoporfin-mediated photodynamic therapy (PDT) is an alternative treatment for port-wine stain (PWS) birthmarks. OBJECTIVE: To evaluate treatment responses and adverse effects associated with Hemoporfin PDT for the treatment of PWS and their management. METHOD: The medical records of 700 patients who underwent PDT treatment in our center were retrospectively examined. Treatment-related reactions and adverse effects were reviewed. RESULT: Different types of PWS lesions and different individuals showed different immediate responses (e.g. swelling, color change, pain). To certain extents these reactions were a useful indicator of the treatment endpoint. Edema and scabbing were the most common post-treatment responses. Short-term (e.g. blister, eczematous dermatitis, cutaneous photosensitivity) and long-term (e.g. pigmentation change, scar formation) adverse effects were generally caused by the phototoxicity associated with the combination of photosensitizer and light exposure. CONCLUSION: Although PDT is a safe treatment alternative for PWS birthmarks, treatment parameters must be selected for each individual patient and cutaneous changes must be monitored during light irradiation to minimize the risk of adverse effects. Over estimation of required light dosage or failure to recognize cutaneous changes associated with adverse effects can increase the risk of a poor outcome.

Haematoporphyrin based photodynamic therapy combined with hyperthermia provided effective therapeutic vaccine effect against colon cancer growth in mice.

Photodynamic therapy (PDT) has become an attractive option used in tumor treatment via its direct tumoricidal activities or its immune-boosting activities. On the other hand, heat shock protein 70 has been found to be largely associated with the establishment of anti-tumor activities offered by hyperthermia treated tumor cells. In the present study, we found that injection of tumor-bearing mice with colon cancer cell line CT-26 treated with haematoporphyrin based photodynamic therapy (hematoporphyrin monomethyl ether based PDT, HMME-PDT) together with hyperthermia demonstrated the most effective therapeutic effects against tumor growth, followed by cells treated by hyperthermia alone. CT-26 cells treated only with HMME-PDT failed to provide any therapeutic effects, although significant cell death was induced by HMME-PDT. Compared to hyperthermia treatment, HMME-PDT induced more efficient surface localization of HSP70 on CT-26 cells which correlated with efficient activation of cytolytic CD8 T cells and with effective anti-tumor responses. Thus, our study demonstrated that the surface expression of HSP70 may play a more important role than the total expression or release of this molecule in the activation of immune responses. And our study offered a novel modified PDT approach to the treatment of tumor cells intrinsically low on HSP70 expression.

Research progress of Hemoporfin--part one: preclinical study.

The second generation photosensitizer Hemoporfin (7(12)-(1-methoxyethyl) -12(7)-(1-hydroxyethyl)-3,8,13,17-tetramethyl-21H,23H-porphin-2,18-dipropionic acid) is a porphyrin derivative which processes a stable structure, high singlet oxygen yield, high photoactivity, low dark toxicity and fast clearance rate. Hemoporfin, also known as hematoporphyrin monomethyl ether (HMME) has been studied and used in photodynamic therapy (PDT) in China since 1989. This series of reports will provide an overview on the preclinical and clinical studies of this PDT photosensitizer. The first part of this series will highlight the results of preclinical studies that focused on the compound's optical characteristics, mechanism of the activities, pharmacological and toxicological properties.

Chronobiological approaches to antiangiogenic photodynamic therapy of tumors: the first experimental evaluation.

UNLABELLED: In research of the last decade, rhythmic (circadian) variations of vascular endothelial growth factor (VEGF) production by tumors were discovered. The present paper authors have earlier synthesized and characterized a new derivative photosensitizer - an immunoconjugate of hematoporphyrin with antiVEGF antibodies. AIM: To elaborate and to test a novel modification of the photodynamic therapy of tumors (PDT) method, founding upon a timed introduction of the immunoconjugated photosensitizer to tumor-bearing animals, so that this coincides with a maximum content of VEGF in tumor tissues. METHODS: Circadian variations of VEGF contents in murine transplanted tumors, Lewis lung carcinoma and sarcoma 180, were determined by ELISA method. Immunoconjugated photosensitizer concentrations in tumors were estimated by spectrofluorometry. Photoirradiation of the tumors was carried out with a red light (wavelength of 635 nm) from a semiconductor laser. Light doses were chosen, calculating on a partial inhibition of tumor growth, in order that a dependence of PDT efficiency on a daily time-moment (circadian rhythm phase) of the treatment could be observed distinctly. RESULTS: Circadian variations of the VEGF levels in Lewis lung carcinoma and sarcoma 180 were demonstrated with the maximum at 14:00 h and the minimum at 02:00 h. Intra-abdominal introduction into tumor-bearing mice of the immunoconjugated photosensitizer resulted in a greater accumulation of the immunoconjugate in tumors at 14:00 h than at 02:00 h. Laser irradiation of carcinomas and sarcomas at 14:00 h or 02:00 h after introduction of the immunoconjugated photosensitizer to mice the day before at the same time points, induced a significantly enhanced inhibition of tumor growth in animals treated at day-time versus those treated at night-time. CONCLUSION: The obtained results justify further attempts to transfer principles of tumor chronochemotherapy onto photodynamic therapy.

Efficacy and safety of hemoporfin in photodynamic therapy for port-wine stain: a multicenter and open-labeled phase IIa study.

BACKGROUND/PURPOSE: This phase IIa study aimed to study the efficacy and safety of hemoporfin in photodynamic therapy (PDT) with a 532 nm continuous laser for port-wine stain (PWS). METHODS: In this 8-week open-labeled study in three centers, three different laser exposure times (532 nm continuous laser for 20, 30 and 40 min) were used in stage I, group A, stage II, group B and stage III, group C, respectively. Primary efficacy assessment was performed by an independent group of experts, who reviewed the standardized photos. Secondary efficacy assessment consisted of the subjective grading of the PWS fading by the investigators and the patients. Treatment reactions and adverse events (AE) were recorded separately. RESULTS: Forty patients were initially enrolled in the study, but stage III had to be cancelled eventually for the safety of the patients. Patients in groups A and B showed similar satisfactory results in efficacy assessments, the total 'response' rate being 80.0% and 94.7% in groups A and B, respectively. The AE rates were also similar in the two groups. Self-limiting photosensitive dermatitis and hyperpigmentation were the most frequently observed AE. CONCLUSION: Hemoporfin-PDT is effective and safe for patients with PWS aged 16-50.

Hematoporphyrin monomethyl ether enhances the killing of ultrasound on osteosarcoma cells involving intracellular reactive oxygen species and calcium ion elevation.

OBJECTIVE: The present study aims to investigate the possible mechanisms of hematoporphyrin monomethyl ether (HMME) enhancing the cytotoxicity of ultrasound in osteosarcoma cells. METHODS: Osteosarcoma cell line UMR-106 was treated by HMME and ultrasound radiation, with the HMME concentration kept at 20 µg/mL and ultrasound radiation for 10 seconds at the intensity of 0.5 W/cm². Cell proliferation was investigated at 12, 24, 36, and 48 hours using MTT assay after ultrasound and HMME treatment. Ultrastructural morphology was observed using transmission electron microscopy (TEM). Intracellular reactive oxygen species (ROS) was measured using a flow cytometry with DCFH-DA staining and intracellular free calcium ion (Ca(2+)) with Fluo-3-AM staining. RESULTS: The UMR-106 cells proliferated rapidly in the sham radiation and HMME treatment alone group, but ultrasound-treated cells and HMME-ultrasound-treated cells proliferated slowly. There was a significant difference between HMME-ultrasound treatment and the controls, including ultrasound radiation, HMME treatment alone, and sham radiation (P < .05). TEM showed endoplasmic reticulum and mitochondrial swelling in the ultrasound-treated cells, and more cells presented apoptosis and necrosis after treatment with ultrasound and HMME together. Intracellular ROS and Ca(2+) in the cells increased more significantly after both ultrasound and HMME treatment than after ultrasound treatment alone. CONCLUSIONS: HMME could effectively enhance the inhibition effect of ultrasound on osteosarcoma cells. Intracellular ROS and Ca(2+) in the UMR-106 cells increased more significantly after the treatment of HMME and ultrasound together, indicating that the enhancement of HMME on ultrasound cytotoxicity to osteosarcoma cells possibly involves both intracellular ROS and Ca(2+) elevation.