Analysis of Hypericin-Mediated Effects and Implications for Targeted Photodynamic Therapy

Photodynamic Therapy: Current Trends and Potential Future Role in the Treatment of Bladder Cancer

Bladder cancer (BC) is the 10th most common cancer in the world. The therapeutic spectrum of BC is broad and is constantly expanding. Despite the wide clinical use of photodynamic diagnosis (PTD) for BC, PDT has not been sufficiently investigated in the treatment landscape of BC. We performed an online search of the PubMed database using these keywords: photodynamic therapy, bladder cancer, urothelial carcinoma, in vivo, in vitro, cell line, animal model. Reviews, case reports, and articles devoted to photodynamic diagnostics and the photodynamic therapy of tumors other than urothelial carcinoma were excluded. Of a total of 695 publications, we selected 20 articles with clinical data, 34 articles on in vivo PDT, and 106 articles on in vitro data. The results presented in animal models highlight the potential use of PDT in the neoadjuvant or adjuvant setting to reduce local recurrence in the bladder and upper urinary tracts. Possible regimens include the combination of PDT with intravesical chemotherapy for improved local tumor control or the integration of vascular-targeted PDT in combination with modern systemic drugs in order to boost local response. We summarize available evidence on the preclinical and clinical application of PDT for urothelial carcinoma in order to explain the current trends and future perspectives.

Vernodalin Triggers ROS-Mediated Apoptosis in TPC-1 Human PapillaryThyroid Cancer Cells via Suppression of the MAPKs Signaling Pathway

BACKGROUND

Thyroid Cancer (TC) is an endocrine organ malignancy that has become more common in recent decades. Vernodalin (VN), a cytotoxic sesquiterpene, has been reported to exhibit anticancer properties against human breast and liver cancer cells. However, no study has explored the efficacy of VN with respect to its antiproliferative and apoptotic action on human Papillary Thyroid Cancer cells (PTC).

OBJECTIVE

The study intended to examine the antitumor and antiproliferative effects of VN and the apoptosis mechanisms underlying its action on TPC-1 human PTC cells.

METHODS

In this study, we examined the VN cell viability by MTT assay; performed ROS measurement by DCFH staining method, MMP identification by Rh-123 staining method, and apoptotic morphological assay by employing AO/EB and DAPI stain method, and further, p38 MAPK/ERK/JNK cell proliferation markers were determined by western blotting technique.

RESULTS

The findings showed that VN could inhibit the growth of PTC cells by increasing intracellular ROS, damaging MMP, and stimulating apoptosis in a concentration-dependent manner. The study demonstrated how VN inhibited TPC-1 cell viability by causing ROS-induced cell death via the MAPK signaling pathway.

CONCLUSION

VN may serve as an agonist to impact apoptosis in PTC cells. In human PTC, VN could play an effective role in chemotherapy. More studies pertaining to animal tumor models are needed to prove its anti-cancer effectiveness in vivo.

Conjugation of Hypericin to Gold Nanoparticles for Enhancement of Photodynamic Therapy in MCF-7 Breast Cancer Cells

Breast cancer, among the different types of cancer, is one of the most diagnosed cancers and the leading cause of mortalities amongst women. Factors, including genetic and epigenetic alterations in tumors, make it resistant to therapies, which results in treatment failures and/or recurrence. Furthermore, the existing therapies have many unfavorable side effects leading to poor prognosis and reduced therapeutic outcomes. Photodynamic therapy (PDT) is one of the most effective cancer therapies with increased selectivity and specificity toward cancer cells. As a result, the use of gold nanoparticles (AuNP) further improves the effectiveness of PDT by increasing the drug loading capacity into the cells. In this study, hypericin (Hyp) photosensitizer (PS) was adsorbed on gold nanoparticles (AuNPs) by sonication to achieve physical adsorption of the PS to AuNP. The resulting compound was characterized by FTIR, Zeta potential, UV-Vis spectroscopy, and TEM. The compound was used for the PDT treatment of MCF-7 human breast cancer in vitro. Cellular responses at 12 h post-PDT at 10 J/cm2 were observed. Cellular morphology, LDH membrane integrity, ATP luminescence assay, and Annexin V/PI staining were performed. The results demonstrated typical cell death morphological features while the biochemical responses indicated increased LDH and decreased ATP levels. In conclusion, this study presents an insight into the application of advanced PDT in breast cancer cells by inducing cancer cell death in vitro via apoptosis.

Hollow microneedle assisted intradermal delivery of hypericin lipid nanocapsules with light enabled photodynamic therapy against skin cancer

Photodynamic therapy (PDT) to manage non-melanoma skin cancers has garnered great attention over the past few years. Hypericin (Hy) is a potent lipid-soluble photosensitiser with promising anticancer therapeutic activities. Nevertheless, its poor water-solubility, aggregation in biological systems and insufficient skin penetration restricted its effective exploitation. Herein, we report for the first-time encapsulation of Hy into lipid nanocapsules (Hy-LNCs), and then application of an AdminPen™ hollow microneedles (Ho-MNs) array and an in-house fabricated Ho-MN to enable efficient intradermal delivery. The physicochemical properties, photoactivity, ex vivo drug distribution and cellular uptake were evaluated. Results showed that Hy-LNCs were successfully formed with a particle size of 47.76 ± 0.49 nm, PDI of 0.12 ± 0.02, high encapsulation efficiency (99.67% ± 0.35), 396 fold higher photoactivity, 7 fold higher skin drug deposition, significantly greater cellular uptake and higher photocytotoxicity compared to free Hy. The therapeutic effect of Hy-LNCs was finally assessed in vivo using a nude mouse model with transplanted tumours. Interestingly, Hy-LNCs delivered by Ho-MN exhibited remarkable anti-tumour destruction (85.84%) after irradiation with 595 nm. This study showed that Ho-MNs-driven delivery of Hy-LNCs followed by irradiation could form a promising minimally invasive, effective and site-specific approach for managing non-melanoma skin cancers.

Advances in Management of Bladder Cancer-The Role of Photodynamic Therapy

Photodynamic therapy (PDT) is a non-invasive and modern form of therapy. It is used in the treatment of non-oncological diseases and more and more often in the treatment of various types of neoplasms in various locations including bladder cancer. The PDT method consists of local or systemic application of a photosensitizer, i.e., a photosensitive compound that accumulates in pathological tissue. Light of appropriate wavelength is absorbed by the photosensitizer molecules, which in turn transfers energy to oxygen or initiates radical processes that leads to selective destruction of diseased cells. The technique enables the selective destruction of malignant cells, as the photocytotoxicity reactions induced by the photosensitizer take place strictly within the pathological tissue. PDT is known to be well tolerated in a clinical setting in patients. In cited papers herein no new safety issues were identified. The development of anti-cancer PDT therapies has greatly accelerated over the last decade. There was no evidence of increased or cumulative toxic effects with each PDT treatment. Many modifications have been made to enhance the effects. Clinically, bladder cancer remains one of the deadliest urological diseases of the urinary system. The subject of this review is the anti-cancer use of PDT, its benefits and possible modifications that may lead to more effective treatments for bladder cancer. Bladder cancer, if localized, would seem to be a good candidate for PDT therapy since this does not involve the toxicity of systemic chemotherapy and can spare normal tissues from damage if properly carried out. It is clear that PDT deserves more investment in clinical research, especially for plant-based photosensitizers. Natural PS isolated from plants and other biological sources can be considered a green approach to PDT in cancer therapy. Currently, PDT is widely used in the treatment of skin cancer, but numerous studies show the advantages of related therapeutic strategies that can help eliminate various types of cancer, including bladder cancer. PDT for bladder cancer in which photosensitizer is locally activated and generates cytotoxic reactive oxygen species and causing cell death, is a modern treatment. Moreover, PDT is an innovative technique in oncologic urology.

Anti-cancer impact of Hypericin in B-CPAP cells: Extrinsic caspase dependent apoptosis induction and metastasis obstruction

Thyroid cancer is the most common type of endocrine-related cancer. According to the literature, its incidence is not very high, but its rate increasing especially in developed countries. With this regard, finding approaches to prevent, and exert anti-tumor activity with the least side effects on the normal cells at the next step after diagnosis is demanded. Herbal medicine is a branch of integrative oncology that seems to be a practically beneficial goddess for cancer treatment in many cases. Here we utilized Hypericin (HYP) to investigate its anti-tumor (apoptotic and anti-metastatic) activity on B-CPAP (a thyroid cancer cell line) and cytotoxicity on TPC-1 (thyroid cancer cell line with wild type TP53) cell lines. To assess whether HYP may exert preventive and anti-tumor effects and does not have a potential side effect, we dubbed the experiments on the fibroblast cells (as a normal cell line). Cytotoxicity and kind of cellular death were examined by MTT and AnnexinV/PI respectively. Extrinsic/intrinsic apoptosis pathway induction was clarified by western blotting on pro/cleaved caspases 9, 8, and 3. According to our data HYP induces an extrinsic apoptosis pathway and no other types (necroptosis, necrosis, etc.) in B-CPAP cells. Moreover, CDH1 mRNA expression calculated to be up-regulated, and that of LGALS3 down-regulated in the B-CPAP cell line after treatment. Besides tumor cytotoxic activity, we suggest that HYP impedes with invasion and/or metastasis process.

Surface tailored zein as a novel delivery system for hypericin: Application in photodynamic therapy

Zein is an FDA-approved maize protein featured by its manipulative surface and the possibility of fabrication into nanomaterials. Although extensive research has been carried out in zein-based technology, limited work is available for the application of zein in the field of cancer photodynamic therapy (PDT). In this work, we report zein as a carrier for the natural photosensitizer hypericin in the PDT of hepatocellular carcinoma in vitro. Zein was modified through chemical PEGylation to form PEGylated zein micelles that were compared with two zein nanoparticle formulations physically stabilized by either the lecithin/pluronic mixture or sodium caseinate. FT-IR, ¹HNMR and HP-SEC MALS approaches were employed to confirm the chemical PEGylation of zein. Our developed zein nanoparticles and micelles were further characterized by photon correlation spectroscopy (PCS) and atomic force microscopy (AFM). The obtained results showed relatively smaller sizes and higher encapsulation of hypericin in the micellar zein than the nanoparticle-based formulations. Phototoxicity on hepatocellular carcinoma (HepG2 cells) manifested a dose-dependent toxicity pattern of all designed zein formulations. However, superior cytotoxicity was prominent for the hypericin-based micelles, which was influenced by the higher cellular uptake profile. Consequently, the treated HepG2 cells manifested a higher level of intracellular generated ROS and disruption of mitochondrial membrane potential, which induced apoptotic cell death. Comparatively, the designed hypericin formulations indicated lower phototoxicity profile in murine fibroblast L929 cells reflecting their safety on normal cells. Our investigations suggested that the surface-modified zein could be employed to enhance the delivery of the hydrophobic hypericin in PDT and pave the way for future in vivo and clinical applications in cancer treatment.

Application of phototherapeutic-based nanoparticles in colorectal cancer

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy and the second leading cause of cancer death, which accounts for approximately 10% of all new cancer cases worldwide. Surgery is the main method for treatment of early-stage CRC. However, it is not effective for most metastatic tumors, and new treatment and diagnosis strategies need to be developed. Photosensitizers (PSs) play an important role in the treatment of CRC. Phototherapy also has a broad prospect in the treatment of CRC because of its low invasiveness and low toxicity. However, most PSs are associated with limitations including poor solubility, poor selectivity and high toxicity. The application of nanomaterials in PSs has added many advantages, including increased solubility, bioavailability, targeting, stability and low toxicity. In this review, based on phototherapy, we discuss the characteristics and development progress of PSs, the targeting of PSs at organ, cell and molecular levels, and the current methods of optimizing PSs, especially the application of nanoparticles as carriers in CRC. We introduce the photosensitizer (PS) targeting process in photodynamic therapy (PDT), the damage mechanism of PDT, and the application of classic PS in CRC. The action process and damage mechanism of photothermal therapy (PTT) and the types of ablation agents. In addition, we present the imaging examination and the application of PDT / PTT in tumor, including (fluorescence imaging, photoacoustic imaging, nuclear magnetic resonance imaging, nuclear imaging) to provide the basis for the early diagnosis of CRC. Notably, single phototherapy has several limitations in vivo, especially for deep tumors. Here, we discuss the advantages of the combination therapy of PDT and PTT compared with the single therapy. At the same time, this review summarizes the clinical application of PS in CRC. Although a variety of nanomaterials are in the research and development stage, few of them are actually on the market, they will show great advantages in the treatment of CRC in the near future.

Hypericin-mediated photodynamic therapy inhibits growth of colorectal cancer cells via inducing S phase cell cycle arrest and apoptosis

Colorectal cancer (CRC) is one type of cancer with high morbidity and mortality worldwide. Photodynamic therapy (PDT), a promising new therapeutic approach for cancer, induces tumor damage through photosensitizer-mediated oxidative cytotoxicity. Hypericin is a powerful photosensitizer with pronounced tumor-localizing properties. In this study, we investigated the phototoxic effects of hypericin-mediated PDT (HYP-PDT) in HCT116 and SW620 cells. We validated that HYP-PDT inhibited cell proliferation, triggered intracellular reactive oxygen species generation, induced S phase cell cycle arrest and apoptosis of HCT116 and SW620 cells. Mechanistically, the results of western blot showed that HYP-PDT downregulated CDK2 expression through decreasing the CDC25A protein, which resulted in the decrease of CDK2/Cyclin A complex. Additionally, HYP-PDT induced DNA damage as evidenced by ATM activation and upregulation of p-H2AX. Further investigation showed that HYP-PDT significantly increased Bax expression and decreased Bcl-2 expression, and then, upregulated the expression of cleaved caspase-9, cleaved caspase-3 and cleaved PARP, thereby inducing apoptosis in HCT116 and SW620 cells. In conclusion, our results indicated that the CDC25A/CDK2/Cyclin A pathway and the mitochondrial apoptosis pathway were involved in HYP-PDT induced S phase cell cycle arrest and apoptosis in colorectal cancer cells, which shows HYP could be a probable candidate used for treating colorectal cancer.

Hypericin-mediated photodynamic therapy for the treatment of cancer: a review

OBJECTIVES

Hypericin is a polycyclic aromatic naphthodianthrone that occurs naturally. It is also an active ingredient in some species of the genus Hypericum. Emerging evidence suggests that hypericin has attracted great attention as a potential anticancer drug and exhibits remarkable antiproliferative effect upon irradiation on various tumour cells. This paper aims to summarise the anticancer effect and molecular mechanisms modulated by hypericin-medicated photodynamic therapy and its potential role in the cancer treatment.

KEY FINDINGS

Hypericin-medicated photodynamic therapy could inhibit the proliferation of various tumour cells including bladder, colon, breast, cervical, glioma, leukaemia, hepatic, melanoma, lymphoma and lung cancers. The effect is primarily mediated by p38 mitogen-activated protein kinase (MAPK), JNK, PI3K, CCAAT-enhancer-binding protein homologous protein (CHOP)/TRIB3/Akt/mTOR, TRAIL/TRAIL-receptor, c-Met and Ephrin-Eph, the mitochondria and extrinsic signalling pathways. Furthermore, hypericin-medicated photodynamic therapy in conjunction with chemotherapeutic agents or targeted therapies is more effective in inhibiting the growth of tumour cells.

SUMMARY

During the past few decades, the anticancer properties of photoactivated hypericin have been extensively investigated. Hypericin-medicated photodynamic therapy can modulate a variety of proteins and genes and exhibit a great potential to be used as a therapeutic agent for various types of cancer.

The changing therapeutic landscape, burden of disease, and unmet needs in patients with cutaneous T-cell lymphoma

Cutaneous T-cell lymphomas (CTCLs) have a chronic, relapsing course, and the most common subtypes are mycosis fungoides and Sézary syndrome. The disease causes visible skin alterations and can also cause alopecia, pruritus and pain, all of which can impact patients' health-related quality of life (HRQoL). The goal of treatment is to reduce symptoms and prevent disease progression. However, treatment recommendations are often based on low levels of evidence due to the lack of well-designed randomised clinical trials and treatment guidelines, and approved drugs vary considerably across different countries and regions. Currently, available treatments rarely lead to durable remissions and eventually become less effective, meaning patients often require multiple therapy changes. Skin-directed therapies (SDTs) are first-line treatments for early-stage CTCL, whereas systemic therapies may be needed for early-stage disease that does not respond to SDT or for advanced-stage disease. However, patients can experience significant side-effects with these treatments or may be unable to tolerate them. Hence, there is an unmet need for effective therapies with good safety profiles for the treatment of early- and late-stage CTCL. Here, we review current treatment guidelines, investigational and approved treatments, the impact of CTCL on patients' HRQoL, and the treatment of pruritus.

Vernodalin induces apoptosis through the activation of ROS/JNK pathway in human colon cancer cells

Colorectal cancer is one of the most leading death-causing cancers in the world. Vernodalin, a cytotoxic sesquiterpene, has been reported to possess anticancer properties against human breast cancer cells. We aimed to examine the anticancer mechanism of vernodalin on human colon cancer cells. Vernodalin was used on human colon cancer cells, HT-29 and HCT116. The cytotoxicity of vernodalin on human colon cancer cells was determined through in vitro 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide assay. Small interfering RNA was used to analyze the cascade activation of mitogen-activated protein kinase (MAPK) pathway, c-Jun N-terminal kinase (JNK) in HT-29, and HCT116 cells against vernodalin treatment. The protein expressions of caspase 3, Bcl-2, and Bax were examined through Western blot analysis. Immunoblot analysis on the JNK, ERK, and p38 MAPK pathways showed increased activation due to vernodalin treatment. It was proven from the JNK and p38 inhibition test that both pathways are significantly activated by vernodalin to induce apoptosis. Our results, collectively, showed the apoptosis-induced anticancer mechanism of vernodalin on human colon cancer cells that was mediated through the activation of JNK pathway and apoptotic regulator proteins. These results suggest that vernodalin could be developed as a potent chemotherapeutic agent for human colorectal cancer treatment.

The Influence of Hypericin-Mediated Photodynamic Therapy on Interleukin-8 and -10 Secretion in Colon Cancer Cells

The aim of this study was to measure the secretion of interleukin (IL)-8 and -10 during an elicited immune response following sublethal doses of hypericin-mediated photodynamic therapy (HY-PDT) in experimental models of residual colon cancer cells in vitro. Investigations were performed on the cancer cell lines SW480 and SW620. Each cell line was exposed to 3 different concentrations of the photosensitizer HY and various doses of irradiation. The cell metabolic activity using an MTT assay was performed and then the measurement of IL-8 and IL-10 secretion was achieved using the Bio-Plex ProTMAssay. There was a statistically significant amplification of IL-8 secretion during HY-PDT in the SW620 cell line (at 1 J/cm2: P = .01, 5 J/cm2: P = .002, and 10 J/cm2: P = .025) and a statistically significant decrease in IL-8 during HY-PDT in the SW480 cell line (at 1 J/cm2: P = .05, 5 J/cm2: P = .035, and 10 J/cm2: P = .035). No statistically significant differences in IL-10 concentration were found following HY-PDT in the SW480 (at 1 J/cm2: P > .4, 5 J/cm2: P = .1, and 10 J/cm2: P = .075) or in the SW620 cell line (at 1 J/cm2: P > .4, 5 J/cm2: P > .4, and 10 J/cm2: P > .4). HY-PDT can both eliminate and control a primary tumor via cytotoxic effects, and at sublethal doses, it can affect IL release by colon cancer cells. In this experiment, this influence depended on the level of tumor cell metastatic activity.

Functionalization Of T Lymphocytes With Citrate-Coated Superparamagnetic Iron Oxide Nanoparticles For Magnetically Controlled Immune Therapy

PURPOSE

Immune activation with T cell tumor infiltration is beneficial for the prognosis of patients suffering from solid cancer. Depending on their immune status, solid tumors can be immunologically classified into three groups: "hot" tumors are infiltrated with T lymphocytes, "cold" tumors are not infiltrated and "immune excluded" tumors are only infiltrated in the peripheral tumor tissue. Checkpoint inhibitors provide new therapeutic options for "hot" tumors by triggering the immune response of T cells. In order to enable this for cold tumors as well, T cells must be enriched in the tumor. Therefore, we use the principle of magnetic targeting to guide T cells loaded with citrate-coated superparamagnetic iron oxide nanoparticles (SPIONCitrate) to the tumor by an externally applied magnetic field.

METHODS

SPIONCitrate were produced by alkaline coprecipitation of iron(II) and iron(III) chloride and in situ coating with sodium citrate. The concentration-dependent cytocompatibility of the particles was determined by flow cytometry and blood stability assays. Atomic emission spectroscopy was used for the quantification of the particle uptake into T lymphocytes. The attractability of the loaded cells was observed by live-cell imaging in the presence of an externally applied magnetic field.

RESULTS

SPIONCitrate displayed good cytocompatibility to T cells and did not show any sign of aggregation in blood. Finally, SPIONCitrate-loaded T cells were strongly attracted by a small external magnet.

CONCLUSION

T cells can be "magnetized" by incorporation of SPIONCitrate for magnetic targeting. The production of the particle-cell hybrid system is straightforward, as the loading process only requires basic laboratory devices and the loading efficiency is sufficient for cells being magnetically controllable. For these reasons, SPIONCitrate are potential suitable candidates for magnetic T cell targeting.

Hypericin-loaded graphene oxide protects ducks against a novel duck reovirus

Novel duck reovirus (NDRV) disease is a serious infectious disease for poultry, for which no effective therapy has been established. Therefore, development of novel antivirals against NDRV is urgently needed. In present study, we developed a complex wherein hypericin (HY), which shows broad-spectrum antiviral activity, was loaded onto graphene oxide (GO), which has a high drug-loading capacity and low cytotoxicity. The antiviral activity of the complex (GO/HY) was studied in DF-1 cells and in ducklings infected with the NDRV TH11 strain. GO/HY showed a dose-dependent inhibition of NDRV replication, which may be attributed to direct virus inactivation or inhibition of virus attachment. Western blotting and indirect immunofluorescence assay (IFA) showed markedly suppressed protein expression in GO/HY-treated NDRV-infected DF-1 cells. Moreover, GO/HY prolonged the survival time of the ducklings by reducing pathological lesions caused by the infection and inhibiting viral replication in the liver and lungs. These results suggest that GO/HY has antiviral activity against NDRV both in vitro and in vivo.

An Electron paramagnetic resonance (EPR) spin labeling study in HT-29 Colon adenocarcinoma cells after Hypericin-mediated photodynamic therapy

Background

Colon cancer affects 1.23 million people worldwide and is the third most common malignant disease in men and the second in women. The only curative treatment is surgical resection, but a significant number of patients develop local recurrence or distant metastases. One of the alternative treatment methods for colon cancer is photodynamic therapy (PDT). In recent years, hypericin (HYP) derived from Hypericum perforatum has been suggested as a strong candidate photosensitizer for PDT. Our interest is focused on the biophysical changes in colon cancer cells in relation to HYP-mediated PDT.

Results

In this study, HYP-mediated PDT at 0.04, 0.08 or 0.15 μM HYP concentrations was performed in HT-29 colon adenocarcinoma cells and the Electron Paramagnetic Resonance (EPR) spectra of the spin labeled cells were obtained. Plasma membranes are already heterogeneous structures; the presence of cancer cells increased the heterogeneity and also fluidity of the plasma membranes. Therefore, the obtained spectra were evaluated by EPRSIMC program, which provides the calculation of heterogeneous structures up to four spectral components with different fluidity characteristics. Generally, two motional patterns were obtained from calculations and the number of them increased at the highest concentration. As the order parameters of the most populated components compared, an increase was observed depending on the HYP concentration. However, because of the heterogeneous structure of membrane, the order parameters of the less populated components did not exhibit a regular distribution.

Conclusion

After HYP-mediated PDT, concentration dependent changes were observed in the domain parameters indicating an increase in the HYP accumulation.

Photodynamic therapy - hypericin tetraether liposome conjugates and their antitumor and antiangiogenic activity

Photodynamic therapy (PDT) is an established noninvasive tumor treatment. The hydrophobic natural occurring pigment hypericin shows a lot of attractive properties for the application in PDT. Hence, the administration to biological systems or patients requires the formulation in drug carriers enabling sufficient bioavailability. Therefore, free hypericin was encapsulated by the thin film hydration method or a hypericin-hydroxypropyl-β-cyclodextrin inclusion complex (Hyp-HPβCD) was incorporated by dehydration-rehydration vesicle method in either conventional or ultra-stable tetraether lipid (TEL) liposomes. The hydrodynamic diameter of the prepared nanoformulations ranged between 127 and 212 nm. These results were confirmed by atomic force microscopy. All liposomes showed a good stability under physiological conditions. TEL liposomes which tend to build more rigid bilayers, generate higher encapsulation efficiencies than their conventional counterparts. Furthermore, the suitability for intravenous application was confirmed by hemocompatibility studies resulting in a hemolytic potential less than 20% and a coagulation time less than 50 sec. The uptake of liposomal hypericin into human ovarian carcinoma cells (SK-OV-3) was confirmed using confocal microscopy and further characterized by pathway studies. It was demonstrated that the lipid composition and intraliposomal hypericin localization influenced the anti-vascular effect in the chorioallantoic membrane (CAM). While hypericin TEL liposomes exhibit substantial destruction of the microvasculature drug-in-cyclodextrin TEL liposomes showed no effect. Nevertheless, both formulations yielded severe photocytotoxicity in SK-OV-3 cells in a therapeutic dosage range. Conclusively, hypericin TEL liposomes would be perfectly suited for anti-vascular targeting while Hyp-HPβCD TEL liposomes could deliver the photosensitizer to the tumor site in a more protected manner.