PD/PDT for gynecological disease: A clinical review

Comparative analysis of photodynamic therapy and conization for cervical high-grade squamous intraepithelial lesion: A systematic review and meta-analysis

OBJECTIVES

This review aims to compare the effectiveness of photodynamic therapy (PDT) with conization, including loop electrosurgical excision procedure (LEEP) and cold-knife conization (CKC), in treating cervical high-grade squamous intraepithelial lesions (HSIL).

METHODS

PubMed, Cochrane Library, Google Scholar, Embase, China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched. The outcomes assessed were complete response (CR) rate, human papillomavirus (HPV) eradication rate, recurrence rate, and adverse events (AEs).

RESULTS

9 studies were included. A total of 312 patients received PDT, while 380 underwent conization (LEEP/CKC). There was no significant difference between PDT and conization in the CR rate at 3-6 months (OR: 1.64 [0.97, 2.76]; P = 0.06), 12-month CR (OR: 0.49 [0.13, 1.90]; P = 0.30), HPV eradication rate at 3-6 months (OR: 1.40 [0.95, 2.07]; P = 0.09), HPV eradication rate at 12 months (OR: 0.92[0.47, 1.82]; P = 0.81), or 12-month recurrence rate (OR: 2.97 [0.62, 14.25]; P = 0.17). However, the rate of AEs, including vaginal bleeding (OR: 0.10 [0.03, 0.33]; P = 0.0002), cervical canal adhesion (OR: 0.16 [0.03, 0.90]; P = 0.04), and cervical scar formation (OR: 0.04 [0.01, 0.30]; P = 0.002), was significantly lower with PDT than with conization. The degree of heterogeneity was not high.

CONCLUSION

Based on our systematic review and meta-analysis, it could be concluded that PDT may be a practical approach for cervical HSIL regression compared to conization (LEEP/CKC). However, further high-quality, controlled trials are needed to confirm these findings.

Hiporfin-photodynamic therapy for high-grade squamous intraepithelial lesions of the endocervical canal in young women

The objective of this prospective study was to assess the efficacy of Hiporfin-photodynamic therapy (PDT) int the treatment of young women diagnosed with high-grade squamous intraepithelial lesions (HSIL) of the endocervical canal. This study included 14 patients aged 30 ± 4.2 years (range 21-37) with HSIL of the cervical canal, treated at our hospital from August 2021 to June 2023. Hiporfin (2 mg/kg) was administered intravenously and laser irradiation with a 630 nm wavelength was performed on the cervical canal and cervical surface 48-72 h later. All patients had been observed for at least 12 months. 64.3% (9/14) were nulliparous. The complete response (CR) rate of cervical canal involvement was 100.0% (14/14) at 3-6 months. Pre-PDT, all patients (14/14) tested positive for high-risk human papilloma virus (HR-HPV). The HPV eradication rate was 64.3% (9/14) at 3-6 months and 85.7% (12/14) at 12 months. No serious adverse effects were observed in patients during or after PDT. No recurrence was noted during the long-time follow-up. 6 patients who planned to get pregnant achieved 6 pregnancies including 1 spontaneous abortion, 2 term pregnancies, and 3 ongoing pregnancies. No fetal loss occurred due to cervical incompetence. Hiporfin-PDT may be a promising, fertility-preserving treatment for HSIL of the endocervical canal in young women.

Photodynamic therapy compared with loop electrosurgical excision procedure in patients with cervical high-grade squamous intraepithelial lesion

The study aimed to compare the effectiveness between Hiporfin-photodynamic therapy (PDT) and loop electrosurgical excision procedure (LEEP) in treating cervical high-grade squamous intraepithelial lesion (HSIL). We conducted a retrospective analysis of 104 women diagnosed with cervical HSIL at our hospital from April 2019 to July 2023. With 1:1 matched case-control, 52 cases received Hiporfin-PDT and 52 cases underwent LEEP. All PDT-treated cases received Hiporfin (2 mg/kg) I.V. and a diode laser at a wavelength of 630-nm. T-test, Chi-square test, Fisher's exact test, and Yates's correction for continuity were conducted for statistical. A P value < 0.05 was considered significant. The complete response (CR) post-PDT at 3rd-6th months,10th-12th months and 24th months was in 98.1% (51/52),100.0% (45/45) and 100.0% (22/22) patients respectively, compared to 98.1% (51/52), 100.0% (46/46) and 100.0% (24/24) patients respectively after LEEP. HPV clearance rates after PDT at 3rd-6th months,10th-12th months and 24th months was 76.9% (40/52), 88.9% (40/45) and 95.5% (21/22) respectively, compared to 69.2% (36/52), 93.5% (43/46) and 95.8% (23/24) respectively after LEEP, with no significant difference between the two groups (P = 0.508, P = 0.687 and P = 1.000, respectively). Postoperative complications in the PDT group were tolerable. The cure rates and HPV eradication of Hiporfin-PDT were comparable with that of LEEP in the management of cervical HSIL. Hiporfin-PDT may serve an alternative method for organ-saving in cervical HSIL.

Precise modulation and use of reactive oxygen species for immunotherapy

Reactive oxygen species (ROS) play an important role in regulating the immune system by affecting pathogens, cancer cells, and immune cells. Recent advances in biomaterials have leveraged this mechanism to precisely modulate ROS levels in target tissues for improving the effectiveness of immunotherapies in infectious diseases, cancer, and autoimmune diseases. Moreover, ROS-responsive biomaterials can trigger the release of immunotherapeutics and provide tunable release kinetics, which can further boost their efficacy. This review will discuss the latest biomaterial-based approaches for both precise modulation of ROS levels and using ROS as a stimulus to control the release kinetics of immunotherapeutics. Finally, we will discuss the existing challenges and potential solutions for clinical translation of ROS-modulating and ROS-responsive approaches for immunotherapy, and provide an outlook for future research.

Successful pregnancy and delivery after HiPorfin photodynamic therapy for cervical high-grade squamous intraepithelial lesion

OBJECTIVE

The study analyzed HiPorfin-Photodynamic therapy (PDT) for young women with cervial high-grade squamous intraepithelial lesion (HSIL) and evaluated the impact of PDT on their pregnancy and delivery.

METHODS

Retrospective analysis of 4 patients (21-33 years old) were treated with HiPorfin® (2 mg/kg) PDT in 2019-2022. 1 patient suffered from cervical intraepithelial neoplasia (CIN)Ⅱ and 3 patients from CIN Ⅲ. 630 nm laser light irradiated the cervical surface and endocervical canal with light dose of 150 J/cm2 and 100-120 J/cm2 respectively.

RESULTS

The median observation time period was 40.5 months. Cure rate, HPV eradication rate and negative conversion rate of cytology were all 100.0 % at 3, 6 and 12 months. All cervical canal lesions completely turned negative. No recurrence occurred during the long-term follow-up period. None of patients suffered from infertility. Three patients delivered vaginally and one delivered by C-section to healthy infants at term.

CONCLUSION

HiPorfin® PDT for cervical HSIL was proved to be a safe method without adverse effects on female fertility and allowing these women to have healthy, full-term children.

Photodynamic therapy with HiPorfin for cervical squamous intraepithelial lesion at childbearing age

OBJECTIVE

To evaluate the clinical efficacy and safety of HiPorfin® photodynamic therapy (PDT) in the treatment of young women at reproductive age with high-grade squamous intraepithelial lesion (HSIL) of the cervix.

METHODS

Prospective study of 41 patients aged 28.8 ± 4.6 years old with cervical intraepithelial neoplasia (CIN) Ⅱ-Ⅲ at Peking University Shenzhen Hospital from March 2019 to January 2023. HiPorfin® (2 mg/kg) was infused intravenously, and 48-72 h later, 630-nm laser irradiation was performed in cervical canal and cervical surface with an irradiation dose of 100-120 J/cm2 and 150 J/cm2 respectively.

RESULTS

All 41 patients with no recurrence had been observed at least 12 months follow-up period after PDT. The number of nulliparous women was 30 (30/41, 73.2 %). CIN Ⅱ were 22 cases (22/41,53.7 %) and CIN Ⅲ were 19 cases (19/41,46.3 %). Complete response (CR) was in 95.5 % (21/22) patients with CIN Ⅱ and 78.9 % (15/19) patients with CIN Ⅲ at 6 months follow-up. Meanwhile, CR rate was 100.0 % (22/22) and 84.2 % (16/19) in CIN Ⅱ and CIN Ⅲ group respectively at 12 months. Pre-treatment, all patients (41/41,100 %) were Human papilloma virus (HPV) positive. HPV eradication rate was 63.4 % (26/41), 73.2 % (30/41) and 92.7 % (38/41) at 3, 6 and 12 months after PDT respectively. Before treatment, cytology ≥ atypical squamous cells of undetermined significance (ASCUS) was 78.0 % (32/41). Negative conversion ratio of cytology was 75.0 % (24/32), 90.6 % (29/32) and 100.0 % (32/32) at 3, 6 and 12 months after PDT respectively. There were no serious adverse effects in patients during and after PDT.

CONCLUSION

HiPorfin-PDT is a promising and organ-saving approach for cervical HSIL, which also eradicates HPV infection effectively and can be a beacon of hope for the young women with fertility preservation requirement.

Combination of phototherapy with immune checkpoint blockade: Theory and practice in cancer

Immune checkpoint blockade (ICB) therapy has evolved as a revolutionized therapeutic modality to eradicate tumor cells by releasing the brake of the antitumor immune response. However, only a subset of patients could benefit from ICB treatment currently. Phototherapy usually includes photothermal therapy (PTT) and photodynamic therapy (PDT). PTT exerts a local therapeutic effect by using photothermal agents to generate heat upon laser irradiation. PDT utilizes irradiated photosensitizers with a laser to produce reactive oxygen species to kill the target cells. Both PTT and PDT can induce immunogenic cell death in tumors to activate antigen-presenting cells and promote T cell infiltration. Therefore, combining ICB treatment with PTT/PDT can enhance the antitumor immune response and prevent tumor metastases and recurrence. In this review, we summarized the mechanism of phototherapy in cancer immunotherapy and discussed the recent advances in the development of phototherapy combined with ICB therapy to treat malignant tumors. Moreover, we also outlined the significant progress of phototherapy combined with targeted therapy or chemotherapy to improve ICB in preclinical and clinical studies. Finally, we analyzed the current challenges of this novel combination treatment regimen. We believe that the next-generation technology breakthrough in cancer treatment may come from this combinational win-win strategy of photoimmunotherapy.

Biocompatible Mesoporous Silica-Polydopamine Nanocomplexes as MR/Fluorescence Imaging Agent for Light-Activated Photothermal-Photodynamic Cancer Therapy In Vivo

Conventional cancer phototherapy with single modality suffers from low therapeutic efficacy and undesired posttreatment damage for adjacent normal tissues. Therefore, the lower NIR laser irradiation power is vital to the reduction or preclusion of risk of scalds and burns in normal tissues. Herein, we rationally proposed a novel multifunctional nanocomplex, which enabled good magnetic resonance (MR) imaging contrast effect and promising photothermal conversion efficacy. The prepared core/shell nanocomplexes [MSN-Ce6@PDA (Mn)] were composed of chlorin e6-embedded mesoporous silica/nanoparticle composites as the cores, and then polydopamine and manganese ions were conjugated on the cores to form protective shells. The MSN-Ce6@PDA (Mn) nanocomplexes revealed superior properties in colloidal stability, photothermal conversion, reaction oxygen species generation, magnetic resonance imaging, etc. Under the guidance of MR and fluorescence imaging, these MSN-Ce6@PDA (Mn) nanocomplexes were found to be primarily accumulated in the MDA-MB-231 tumor area. Furthermore, the combined photodynamic and photothermal therapy exhibited strong inhibition to the growth of MDA-MB-231 tumor in vitro and in vivo. Besides, the MSN-Ce6@PDA (Mn) nanocomplexes also exhibited excellent biocompatibility and low damage to the healthy animals. Hence, the results demonstrated that the prepared MSN-Ce6@PDA (Mn) nanocomplex would be a promising potential for multimodal imaging-guided phototherapy.

The effect of 5-Aminolaevulinic Acid Photodynamic Therapy versus CO2 laser in the Treatment of Cervical Low-grade Squamous Intraepithelial Lesions with High-Risk HPV Infection: A non-randomized, controlled pilot study

BACKGROUND

There are insufficient studies comparing the efficacy of 5-aminolaevulinic acid (ALA) photodynamic therapy (PDT) against CO₂ laser therapy in the treatment of cervical low-grade squamous intraepithelial lesion (LSIL) with high-risk human papillomavirus (HR-HPV), especially for long-term efficacy.

METHODS

Patients with cervical LSIL and HR-HPV infection were divided into two treatment groups based on their own choice. All patients had a follow-up test including HPV testing, cytology and colposcopy at 4-6 months and 12 months after the treatment.

RESULTS

(1) Among 277 patients, 176 patients received 5-ALA PDT and 101 patients received CO₂ laser therapy. (2) 4-6 months after treatment, there was no significant difference between two groups in the complete remission (CR) rates of cervical LSIL and the clearance rate of HR-HPV infection. (3) 12 months after treatment, compared with the CO₂ laser group, the CR rates of cervical LSIL in the 5-ALA PDT group was significantly higher than the CO₂ laser group. There was no statistical difference in the clearance rate of HR-HPV infection between the two groups. (4) 12 months after treatment, the recurrence rate of cervical lesions and the reinfection rate of HR-HPV infection in 5-ALA PDT group were significantly lower than those in CO₂ laser group.

CONCLUSION

The effect of 5-ALA PDT is similar to CO₂ laser at 4-6 months. The long-term efficacy of 5-ALA PDT appears better than CO₂ laser. As a non-invasive treatment, 5-ALA PDT is a highly effective therapeutic procedure for cervical LSIL with HR-HPV infection.

A multilayered cancer-on-a-chip model to analyze the effectiveness of new-generation photosensitizers

Three-dimensional (3D) cellular models of cancer tissue are necessary tools to analyze new anticancer drugs under in vitro conditions. Diagnostics and treatment of ovarian cancer are major challenges for current medicine. In our report we propose a new three-dimensional (3D) cellular model of ovarian cancer which can mimic a fragment of heterogeneous cancer tissue. We used Lab-on-a-chip technology to create a microfluidic system that allows cellular multilayer to be cultured. Cellular multilayer mimics the structure of two important elements of cancer tissue: flesh and stroma. For this reason, it has an advantage over other in vitro cellular models. We used human ovarian fibroblasts (HOF) and human ovarian cancer cells in our research (A2780). In the first stage of the study, we proved that the presence of non-malignant fibroblasts in co-culture with ovarian cancer cells stimulates the proliferation of cancer cells, which is important in the progression of ovarian cancer. In the next stage of the research, we tested the usefulness of the newly-developed cellular model in the analysis of anticancer drugs and therapies under in vitro conditions. We tested two photosensitizers (PS): free and nanoencapsulated meso-tetrafenylporphyrin, and we evaluated the potential of these drugs in anticancer photodynamic therapy (PDT) of ovarian cancer. We also studied the mechanism of PDT based on the analysis of the level of reactive oxygen species (ROS) in cell cultures. Our research confirmed that the use of new-generation PS can significantly increase the efficacy of PDT in the treatment of ovarian cancer. We also proved that the newly-developed 3D cellular model is suitable for rapid screening of anticancer drugs and has the potential to be used clinically in the future, e.g. in the selection of treatment methods for anticancer personalized medicine.

Effects of core titanium crystal dimension and crystal phase on ROS generation and tumour accumulation of transferrin coated titanium dioxide nanoaggregates

Radionuclide-stimulated therapy (RaST), which is enhanced by Cherenkov radiation, has enabled deep tissue stimulation of UV photosensitizers, providing a new path for cancer treatment. Previous reports have shown UV-active titanium dioxide (TiO₂) nanoparticles (NPs) modified with transferrin inhibit tumour growth after orthogonal treatment with Cherenkov radiation-emitting radionuclides such as ¹⁸F-fluorodeoxyglucose (FDG). However, poor understanding of TiO₂ NP parameters on reactive oxygen species (ROS) generation and particle distribution limits effective therapy. Here we sought to delineate the effects of crystal phase and core TiO₂ crystal dimension (cTd) on ROS production and particle morphology. We prepared Transferrin (Tf)-TiO₂ nanoaggregates (NAGs) using solvothermally synthesized cTd sizes from 5 to 1000 nm diameter and holo- or apo-transferrin. Holo-transferrin was unable to stabilize TiO₂ NPs while apo-transferrin stabilized TiO₂ into uniform nanoaggregates (NAGs), which were invariant with differing cTd, averaging 116 ± 1.04 nm for cTds below 100 nm. ROS production increased from 5 to 25 nm cTd, attaining a peak at 25 nm before decreasing with larger sizes. The supra-25 nm ROS production decrease was partially driven by a ~1/r ³ surface area decline. Additionally, amorphous TiO₂ of equal core size exhibited a 2.6-fold increase in ROS production compared to anatase NAGs, although limited stability halted further use. Although both 5 and 25 nm anatase cTds formed similarly sized NAGs, 5 nm anatase showed a four-fold higher tumour-to-muscle ratio than the 25 nm NPs in tumour-bearing mice, demonstrating the intricate relationships between physical and biological properties of NAGs. The combined in vivo and ROS results demonstrate that anatase crystals and cTd size of 25 nm or less are ideal particle parameters to balance biodistribution with ROS production efficiency.

Diminished viability of human ovarian cancer cells by antigen-specific delivery of carbon monoxide with a family of photoactivatable antibody-photoCORM conjugates

Antibodies conjugated to a photoactive transition metal carbonyl complex afford antigen-directed delivery of cytotoxic carbon monoxide to ovarian cancer cells.

Carbon monoxide (CO)-releasing antibody conjugates were synthesized utilizing a photoactivatable CO-releasing molecule (photoCORM) and mouse monoclonal antibodies linked by a biotin-streptavidin system. Different monoclonal antibodies raised against different surface-expressed antigens that are implicated in ovarian cancer afforded a family of antibody-photoCORM conjugates (Ab-photoCORMs). In an immunosorbent/cell viability assay, Ab-photoCORMs accumulated onto ovarian cancer cells expressing the target antigens, delivering cytotoxic doses of CO in vitro. The results described here provide the first example of an “immunoCORM”, a proof-of-the-concept antibody-drug conjugate that delivers a gaseous molecule as a warhead to ovarian cancer.

Optical coherence tomography in gynecology: a narrative review

Modern gynecologic practice requires noninvasive diagnostics techniques capable of detecting morphological and functional alterations in tissues of female reproductive organs. Optical coherence tomography (OCT) is a promising tool for providing imaging of biotissues with high resolution at depths up to 2 mm. Design of the customized probes provides wide opportunities for OCT use in gynecology. This paper contains a retrospective insight into the history of OCT employment in gynecology, an overview of the existing gynecologic OCT probes, including those for combination with other diagnostic modalities, and state-of-the-art application of OCT for diagnostics of tumor and nontumor pathologies of female genitalia. Perspectives of OCT both in diagnostics and treatment planning and monitoring in gynecology are overviewed.

Clinical efficacy of photodynamic therapy

Objective

The management of cervical intraepithelial neoplasia (CIN) and early invasive cancer of the uterine cervix is very difficult to approach, especially in case of young woman who wants to preserve her fertility. Conization of the cervix may have various kinds of disadvantage. The objective of this clinical retrospective study is to investigate the therapeutic effects and clinical efficacy of photodynamic therapy (PDT) including combined chemo-photodynamic therapy in patients with pre-malignant CIN and malignant invasive cervical cancer.

Methods

Total number of PDT trial case was 50 cases and total number of patient was 22 patients who registered to PDT clinic. We used photogem sensitizer and 632 nm diode laser in early two cases. After then we performed PDT using photofrin sensitizer and 630 nm diode laser in other cases. We used flat-cut, microlens, cylindrical diffuser, and interstitial type optic fibers in order to irradiate the lesions. 240 J/cm² energy was irradiated to the lesions.

Results

CIN 2 were 4 cases (18.2%) and CIN 3 were 15 (68.2%) and invasive cervical cancer were 3 (13.6%). Complete remission (CR) was found in 20 patients (91%). One case of 19 patients with CIN lesion recurred at 18 months after PDT treatment. CR was found in 18 cases in the patients with CIN lesions (95%). CR was found in 2 cases in the patients with invasive cervical cancer (67%).

Conclusion

Our data showed that CR rate was fantastic in CIN group (95%). This study suggests that PDT can be recommended as new optimistic management modality on the patients with pre-malignant CIN lesions including carcinoma in situ and relatively early invasive cancer of the uterine cervix. Combined chemo-photodynamic therapy is essential in case of invasive cervical cancer. For the young age group who desperately want to preserve their fertility and have a healthy baby, PDT can be a beacon of hope.

Mitochondrial selectivity and remarkable photocytotoxicity of a ferrocenyl neodymium(iii) complex of terpyridine and curcumin in cancer cells

A mixed-ligand neodymium(iii) complex of ferrocene appended terpyridine and curcumin targets the mitochondria and shows remarkable visible-light induced cytotoxicity in HeLa and MCF-7 cancer cells while being much less toxic in dark and to MCF-10A normal cells.

Remarkable visible light-triggered cytotoxicity of mitochondria targeting mixed-ligand cobalt(iii) complexes of curcumin and phenanthroline bases binding to human serum albumin

Co(iii) complexes of curcumin and phenanthroline bases show remarkable visible-light induced cytotoxicity in HeLa cells but are much less toxic in dark and to normal cells. The complexes bind to HSA with significant affinity.

Photodynamic therapy: oncologic horizons

Photodynamic therapy (PDT) is a light-based intervention with a long and successful clinical track record for both oncology and non-malignancies. In cancer patients, a photosensitizing agent is intravenously, orally or topically applied and allowed time to preferentially accumulate in the tumor region. Light of the appropriate wavelength and intensity to activate the particular photosensitizer employed is then introduced to the tumor bed. The light energy will activate the photosensitizer, which in the presence of oxygen should allow for creation of the toxic photodynamic reaction generating reactive oxygen species. The photodynamic reaction creates a cascading series of events including initiation of apoptotic and necrotic pathways both in tumor and neovasculature, leading to permanent lesion destruction often with upregulation of the immune system. Cutaneous phototoxicity from unintentional sunlight exposure remains the most common morbidity from PDT. This paper will highlight current research and outcomes from the basic science and clinical applications of oncologic PDT and interpret how these findings may lead to enhanced and refined future PDT.

Photodynamic detection of oral cancers with high-performance chitosan-based nanoparticles

Oral cancer, a subtype of head and neck cancer, is one of the leading causes of cancer death and is difficult to detect in the early stages. Improved methods of detecting primary oral lesions during endoscopy would significantly improve cancer survival rates. Here we report a high-performance nanoparticle for photodynamic detection of oral cancer. Succinate-modified chitosan (SCHI) is physically complexed with folic-acid-modified chitosan to form nanoparticles with a high drug loading efficiency and to improve drug release in the cellular lysosome. The z-average diameter and zeta potential of the prepared nanoparticles (fSCN) were 110.0 nm and 18.6 mV, respectively, enough to keep the nanoparticles stable in aqueous suspension without aggregating. When loaded with 5-aminolaevulinic acid (5-ALA; 72.8% loading efficiency) in the prepared fSCNA, there were no significant differences between the fSCN and fSCNA in particle size or zeta potential. Moreover, the fSCNA nanoparticles were readily engulfed by oral cancer cells via folate-receptor-mediated endocytosis. The release of loaded 5-ALA in the lysosome was promoted by the reduced attraction intensity between chitosan and 5-ALA via the deprotonated SCHI molecules, which resulted in a higher accumulation of intracellular protoporphyrin IX (PpIX) for photodynamic detection. These results demonstrate that N-succinyl-chitosan-incorporated and folic-acid-conjugated chitosan nanoparticles are an excellent vector for oral-specific delivery of 5-ALA for fluorescent endoscopic detection.

Cytotoxicity of cyclometallated ruthenium complexes: the role of ligand exchange on the activity

The cyclometallated Ru(II) complexes cis-[Ru(phpy)(phen)(CH3CN)2](PF6) (1; phpy(-)=deprotonated 2-phenylpyridine, phen=1,10-phenanthroline) and cis-[Ru(phpy)(bpy)(CH3CN)2](PF6) (2; bpy=2,2'-bipyridine) were investigated as potential agents for photodynamic therapy. The presence of phpy(-) in the coordination sphere results in a red-shift of the Ru→phen and Ru→bpy metal-to-ligand charge transfer of 1 and 2, respectively, thus improving the tissue penetration of light while maintaining the efficient photo-induced ligand exchange required for DNA binding. The 14-fold enhancement of OVCAR-5 cell death that occurs upon irradiation with 690 nm light can be attributed to photo-aquation. The role of glutathione (GSH) on the toxicity of the complex was also explored. Complexes 1 and 2 undergo ligand substitution in the presence of GSH in the dark, such that the metal may covalently bind to biomolecules. The combination of photo-induced ligand exchange and GSH-facilitated ligand exchange may explain the observed cytotoxicity.

Relationship between structure and photoactivity of porphyrins derived from protoporphyrin IX

Protoporphyrin (Pp IX) derivatives were prepared to study the relationship between photosensitizer structure and photoactivity, with an emphasis on understanding the role of membrane interactions in the efficiency of photosensitizers used in photodynamic therapy (PDT). The synthetic strategies described here aimed at changing protoporphyrin periferic groups, varying overall charge and oil/water partition, while maintaining their photochemical properties. Three synthetic routes were used: (1) modification of Pp IX at positions 31 and 81 by addition of alkyl amine groups of different lengths (compounds 2–5), (2) change of Pp IX at positions 133 and 173, generating alkyl amines (compounds 6 and 7, a phosphate amine (compound 8, and quarternary ammonium compounds (compounds 9 and 10), and (3) amine-alkylation of Hematoporphyrin IX (Hp IX) at positions 31, 81, 133 and 173(compound 12). Strategy 1 leads to hydrophobic compounds with low photocytotoxicity. Strategy 2 leads to compounds 6–10 that have high levels of binding/incorporation in vesicles, mitochondria and cells, which are indicative of high bioavailability. Addition of the phosphate group (compound 8), generates an anionic compound that has low liposome and cell incorporation, plus low photocytotoxicity. Compound 12 has intermediate incorporation and photocytotoxic properties. Compound modification is also associated with changes in their sub-cellular localization: 30% of 8 (anionic) is found in mitochondria as compared to 95% of compound 10 (cationic). Photocytotoxicity was shown to be highly correlated with membrane affinity, which depends on the asymmetrical and amphiphilic characters of sens, as well as with sub-cellular localization.

Temoporfin (Foscan®, 5,10,15,20-tetra(m-hydroxyphenyl)chlorin)--a second-generation photosensitizer

This review traces the development and study of the second-generation photosensitizer 5,10,15,20-tetra(m-hydroxyphenyl)chlorin through to its acceptance and clinical use in modern photodynamic (cancer) therapy. The literature has been covered up to early 2011.

Large payloads of gold nanoparticles into the polyamine network core of stimuli-responsive PEGylated nanogels for selective and noninvasive cancer photothermal therapy

A biocompatible photothermal nanomedicine based on a PEGylated nanogel containing gold nanoparticles (GNPs) in a cross-linked network core of stimuli-responsive poly[2-(N,N-diethylamino)ethyl methacrylate] (PEAMA) gel for cancer photothermal therapy (PTT) was prepared through the reduction of Au(iii) ions without any reducing agents. The influence of the reduction conditions, such as pH, temperature, and N/Au ratio (molar ratio of the amino groups in the PEGylated nanogel to the Au(iii) ions), on the formation of the GNPs in the stimuli-responsive PEAMA gel core (reducing environment) was also studied. Note that the PEGylated nanogel containing GNPs prepared at pH 6, 60 degrees C and N/Au = 1 (PEGylated GNG (1)) was found to have the highest GNP-loading capacity with a diameter of about 8 nm, as observed by TEM; viz., about 27 GNPs formed in a single PEAMA gel core. PEGylated GNG (1) showed a remarkable photothermal efficacy (DeltaT = 7.7 degrees C) under irradiation with Ar ion (Ar(+)) laser (514.5 nm) at a fluence of 39 W cm(-2) for 6 min (14 kJ cm(-2)). Note that PEGylated GNG (1) showed non-cytotoxicity in the absence of irradiation with Ar(+) laser (480 microg mL(-1): > 90% cell viability), whereas pronounced cytotoxicity (IC(50) = 110 microg mL(-1)) was observed for PEGylated GNG (1) under irradiation with Ar(+) laser at a fluence of 26 W cm(-2) for 5 min (7.8 kJ cm(-2)), because of the heat-generation from the GNPs in the cells, which resulted in selective and noninvasive cancer PTT. Thus, PEGylated GNG (1), which has a high GNP-loading capacity, would be a promising nanomedicine for cancer PTT.

Screening of nanoparticulate delivery systems for the photodetection of cancer in a simple and cost-effective model

AIMS

In urology, fluorescence-based imaging methods have been proven to significantly improve the detection of small, barely visible tumors and reduce the recurrence rate. Under ethical and economical pressure, new effective screening systems have to be developed to exploit and assess novel strategies for fluorescence photodetection in other areas. For this purpose, the chorioallantoic membrane (CAM) of the developing chick embryo is an attractive alternative model to the mammalian models.

MATERIALS & METHODS

Hypericin encapsulated into nanoparticles for the photodetection of ovarian metastases was evaluated in the CAM model with respect to vascular extravazation and tumor targeting and compared with free drug following intravenous administration.

RESULTS

To validate the CAM model as a valuable screening system for photodetection of cancer, we drew a comparison with results obtained on a conventional rodent model.

CONCLUSION

Rodent and CAM models led to the same conclusion regarding the benefits of nanoencapsulation to improve selective accumulation of drug in ovarian micrometastases.

A fluorinated ruthenium porphyrin as a potential photodynamic therapy agent: synthesis, characterization, DNA binding, and melanoma cell studies

When the new porphyrin 5,10-(4-pyridyl)-15,20-(pentafluorophenyl)porphyrin is reacted with 2 equiv of Ru(bipy)(2)Cl(2) (where bipy = 2,2'-bipyridine) formation of the target ruthenated porphyrin is achieved with 40% yield. Strong electronic transitions are observed in the visible region of the spectrum associated with the porphyrin Soret and four Q-bands. A shoulder at slightly higher energy than the Soret band is attributed to the Ru(dpi) to bipy(pi*) metal to ligand charge transfer (MLCT) band. The bipyridyl pi to pi* transition occurs at 295 nm. Cyclic voltammetry experiments reveal two single-electron redox couples in the cathodic region at E(1/2) = -0.80 and -1.18 V vs Ag/AgCl associated with the porphyrin. Two overlapping redox couples at E(1/2) = 0.83 V vs Ag/AgCl due to the Ru(III/II) centers is also observed. DNA titrations using calf thymus (CT) DNA and the ruthenium porphyrin give a K(b) = 7.6 x 10(5) M(-1) indicating a strong interaction between complex and DNA. When aqueous solutions of supercoiled DNA and ruthenium porphyrin are irradiated with visible light (energy lower than 400 nm), complete nicking of the DNA is observed. Cell studies show that the ruthenated porphyrin is more toxic to melanoma skin cells than to normal fibroblast cells. When irradiated with a 60 W tungsten lamp, the ruthenium porphyrin preferentially leads to apoptosis of the melanoma cells over the normal skin cells.

Benefits of nanoencapsulation for the hypercin-mediated photodetection of ovarian micrometastases

The high recurrence and lethality of ovarian cancer at advanced stages is problematic, especially due to the development of numerous micrometastases scattered throughout the abdominal cavity. Fluorescence photodetection (PD) used in combination with surgical resection of malignant tissues has been suggested to improve recovery. Based on promising in vivo results for the detection of bladder cancer, hypericin (Hy), a natural photosensitizer (PS), stands as a good candidate for the photodetection of ovarian cancer. However, due to its hydrophobicity, systemic administration of Hy is problematic. Polymeric nanoparticles (NPs) help to overcome these delivery and stability problems and enable intravenous administration of Hy. In this study, Hy-loaded NPs of polylactic acid were produced with the following properties: (i) mean size of 268 nm, (ii) negative zeta potential, (iii) low residual surfactant and (iv) drug loading of 3.7 % (w/w). The potential of hypericin-loaded nanoparticles for the fluorescence photodetection of ovarian metastases in Fischer 344 rats bearing ovarian tumours was compared to free drug. The selectivity of Hy administered with both formulations was assessed first by fluorescence endoscopy, and then quantified after tissue extraction. The results showed an improved selective accumulation of Hy in ovarian micrometastases when NPs were used.

Photodynamic therapy with a new photosensitizing agent

OBJECTIVE

The aim of this study was to investigate the cytotoxicity of octal-bromide zinc phthalocyanine (ZnPcBr(8)) before and after irradiation with a low-power laser (AsGaAl) and analyze the effects of photodynamic therapy (PDT) on the nucleus of L929 cells.

BACKGROUND DATA

One of the most recent and promising applications of phthalocyanine in medicine is in the detection and cure of tumors. We studied the ZnPcBr(8) in agreement with the development of new photosensitizing agents for curing tumors.

METHODS

L929 cells were cultivated at standard conditions, incubated with ZnPcBr(8) for 1 h at different concentrations, irradiated with a semiconductor laser, and incubated in MEM medium for 1, 12, or 24 h. Cells were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) technique and fluorescence microscopy.

RESULTS

The results demonstrated that ZnPcBr(8) at 1 microM was the most effective concentration for PDT, with a decrease of 63% after 1 h, 99% after 12 h, and 100% after 24 h in relation to the control group. The fluorescence microscopy results showed that ZnPcBr(8) was localized in the perinuclear region when analyzed 1 h after incubation. Nucleus staining with DAPI made it possible to observe that nuclear fragmentation occurred 24 h after PDT, cytoplasm retraction at 1, 12, and 24 h after PDT, and vacuoles along the cytoplasm at 12 and 24 h after PDT.

CONCLUSION

According to the results obtained in this study, L929 cell death caused by PDT with ZnPcBr(8) possesses characteristics of apoptosis mediated by the mitochondria, due to the decrease in cells viability, the subcellular localization, and the photodamage found.

Hypericin-loaded nanoparticles for the photodynamic treatment of ovarian cancer

A photodynamic approach has been suggested to improve diagnosis and therapy of ovarian cancer. As Hypericin (Hy), a natural photosensitizer (PS) extracted from Hypericum perforatum, has been shown to be efficient in vitro and in vivo for the detection or treatment of other cancers, Hy could also be a potent tool for the treatment and detection of ovarian cancer. Due to its hydrophobicity, systemic administration of Hy is problematic. Thus, polymeric nanoparticles (NPs) of polylactic acid (PLA) or polylactic-co-glycolic acid (PLGA) were used as a drug delivery system. Hy-loaded NPs were produced with the following characteristics: (i) size in the 200-300 nm range, (ii) negative zeta potential, (iii) low residual PVAL and (iv) drug loading from 0.03 to 0.15% (w/w). Their in vitro photoactivity was investigated on the NuTu-19 ovarian cancer cell model derived from Fischer 344 rats and compared to free drug. Hy-loaded PLA NPs exhibited a higher photoactivity than free drug. Increasing light dose or incubation time with cells induced an enhanced activity of Hy-loaded PLA NPs. Increased NP drug loading had a negative effect on their photoactivity on NuTu-19 cells: at the same Hy concentration, the higher was the drug loading, the lower was the phototoxic effect. The influence of NP drug loading on the Hy release from NPs was also investigated.

The future of photodynamic therapy in oncology

The medicinal properties of light-based therapies have been appreciated for millennia. Yet, only in this century have we witnessed the birth of photodynamic therapy (PDT), which over the last few decades has emerged to prominence based on its promising results and clinical simplicity. The fundamental and distinguishing characteristics of PDT are based on the interaction of a photosensitizing agent, which, when activated by light, transfers its energy into an oxygen-dependent reaction. Clinically, this photodynamic reaction is cytotoxic and vasculotoxic. While the current age of PDT is based on oncological therapy, the future of PDT will probably show a significant expansion to non-oncological indications. This harks back to much of the original work from a century ago. Therefore, this paper will attempt to predict the future of PDT, based in part on a review of its origin.