Comparative study of the phototoxicity of two chrolin type photosensitizers, ATX-S10(Na) and verteporfin, on vascular endothelial and retinal pigment epithelial cells

Design of new protein drug delivery system (PDDS) with photoactive compounds as a potential application in the treatment of glioblastoma brain cancer

Glioblastoma multiforme (GBM) is an extremely aggressive malignant brain tumor. Despite advances in treatment modalities, it remains largely incurable. This unfavorable prognosis for GBM is at least partly due to the lack of a successful drug delivery system across the blood-brain barrier (BBB). The delivery of drugs through nanomedicines combined with less invasive alternative therapies represents an important hope for the future of these incurable brain tumors. Whey protein nanocarriers represent promising strategy for targeted drug delivery to tumor cells by enhancing the drug's bioavailability and distribution, and reducing the body's response towards drug resistance. They have been extensively studied to find new alternatives for capacity to encapsulate different drugs and no need for cross-linkers. In this study, we report for the first time the incorporation and administration of Aluminum phthalocyanine chloride (AlClPc)-loaded whey protein drug delivery system (AlClPc-PDDS) for the treatment of glioblastoma brain cancer. This system was designed and optimized (with the use of the spray drying technique) to obtain the required particle size (in the range of 100 to 300 nm), zeta potential and drug loading. Our results suggest that we have developed a drug delivery system from a low-cost raw material and preparation method that is capable of incorporating hydrophobic drugs which, in combination with irradiation, cause photodamage to neoplasic cells, working as an effective adjuvant treatment for malignant glioma.

Understanding and improving assays for cytotoxicity of nanoparticles: what really matters?

Despite years of excellent individual studies, the impact of nanoparticle (NP) cytotoxicity studies remains limited by inconsistent data collection and analysis. It is often unclear how exposure conditions can be used to determine cytotoxicity quantitatively. Discrepancies due to using different measurement conditions, readouts and controls to characterize NP interactions with cells lead to further challenges. To examine which parameters are critical in NP cytotoxicity studies, we have chosen to examine two NP types (liposomes and quantum dots) at different concentrations incubated with two primary vascular endothelial cells, HUVEC and HMVEC-C for a standard time of 24 h. We paid close attention to the effects of positive controls and cell association on interpretation of cytotoxicity data. Various cellular responses (ATP content, oxidative stress, mitochondrial toxicity, and phospholipidosis) were measured in parallel. Interestingly, cell association data varied significantly with the different image analyses. However, cytotoxicity responses could all be correlated with exposure concentration. Cell type did have an effect on cytotoxicity reports. Most significantly, NP cytotoxicity results varied with the inclusion or exclusion of positive controls. In the absence of positive controls, one tends to emphasize small changes in cell responses to NPs.

Verteporfin

Photodynamic therapy (PDT) with verteporfin (Visudyne), a photosensitising protoporphyrin derivative, is used in the management of subfoveal choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD) or pathological myopia (PM). PDT with verteporfin over 1 and 2 years reduces the decline in visual acuity in patients with classic-containing subfoveal CNV secondary to AMD. Verteporfin is generally well tolerated by most patients. Verteporfin is also effective in patients with CNV secondary to PM, although data in this indication are limited and further controlled studies are required. Although verteporfin has shown efficacy in patients with occult AMD-related subfoveal CNV lesions in early trials, data are currently limited on its first-line use in this indication; fully published data from the Verteporfin In Occult (VIO) trial are therefore awaited with interest. Verteporfin should be considered as a first-line treatment in patients with predominantly classic subfoveal CNV secondary to AMD, and in patients with smaller minimally classic subfoveal CNV lesions. It may also be considered an option for the treatment of patients with occult AMD-related subfoveal CNV in whom visual acuity decreases or predominantly classic features develop over time.

Novel transdermal photodynamic therapy using ATX-S10·Na(II) induces apoptosis of synovial fibroblasts and ameliorates collagen antibody-induced arthritis in mice

We aimed to test the effect of transdermal photodynamic therapy (PDT) on synovial proliferation in vitro and in vivo, using a novel photosensitizer, ATX-S10.Na(II). Synovial fibroblasts were obtained from patients with RA (RASF). Cell viability with or without PDT was determined by MTT assay. Cell morphology was examined by light and transmission electron microscopy. DNA fragmentation was labeled by TUNEL stain. Collagen antibody-induced arthritis (CAIA) was induced in DBA/1 mice, and the effects of transdermal PDT were evaluated by clinical and histological examination. PDT showed drug concentration-dependent and laser dose-dependent cytotoxicity on RASF. TUNEL stain and TEM study revealed the induction of apoptotic cell death of RASF. Transdermal PDT significantly reduced clinical arthritis and synovial inflammation in this model of arthritis. These results suggest that transdermal PDT using ATX-S10.Na(II) might be a novel less invasive treatment strategy for small joint arthritis and tenosynovitis.

The study of the characteristic of photocytotoxicity under high peak power pulsed irradiation with ATX-S10Na(II) in vitro

We studied hydrophilic photosensitizer ATX-S10Na(II) mediated photocytotoxicity against macrophage-like cell under pulsed irradiation. We found that photocytotoxicity suppression under high intensity irradiation was directly induced by a decrease in the Type-II photoreaction. We showed that this decrease was not attributable to absorption saturation with the high intensity irradiation. We found the cell lethality change from 70% to 13% with the pulse peak power density ranging from 0.29 MW/cm(2) to 1.36 MW/cm(2), at the light dose of 20 J/cm(2) and the pulse repetition rate at 40 Hz. To investigate the Type-II reaction, we measured the photobleaching, oxygen consumption and singlet oxygen luminescence of the photosensitizer solution. The transient absorption from the photosensitizer during the irradiation was measured with the pump-and-probe technique. We believe that the photocytotoxicity suppression induced by the high intensity irradiation might be useful for the treatment of depth-controlled photodynamic therapy without the wall damage of a hollow organ.