RESUMEN

Over the years, the performance of the liposomal formulations of temoporfin, Foslip® and Fospeg®, was investigated in a broad array of cell-based assays and preclinical animal models. So far, little attention has been paid to the influence of drug release and liposomal stability on the plasma concentration-time profile. The drug release is a key attribute which impacts product quality and the in vivo efficacy of nanocarrier formulations. In the present approach, the in vitro drug release and the drug-protein transfer of Foslip® and Fospeg® was determined using the dispersion releaser technology. To analyze the stability of both formulations in physiological fluids, nanoparticle tracking analysis was applied. A comparable drug release behavior and a high physical stability with a vesicle size of approximately 92 ± 2 nm for Foslip® and at 111 ± 5 nm for Fospeg® were measured. The development of a novel hybrid in silico model resulted in an optimal representation of the in vivo data. Based on the information available for previous formulations, the model enabled a prediction of the performance of Foslip® in humans. To verify the simulations, plasma concentration-time profiles of a phase I clinical trial were used. An absolute average fold error of 1.4 was achieved. Moreover, a deconvolution of the pharmacokinetic profile into different fractions relevant for the in vivo efficacy and safety was achieved. While the total plasma concentration reached a cmax of 2298 ng/mL after 0.72 h, the monomolecular drug accounted for a small fraction of the photosensitizer with a cmax of 321 ng/mL only.

Asunto(s)

Simulación por Computador , Mesoporfirinas/farmacocinética , Nanopartículas , Fármacos Fotosensibilizantes/farmacocinética , Ensayos Clínicos Fase I como Asunto , Liberación de Fármacos , Estabilidad de Medicamentos , Humanos , Liposomas , Mesoporfirinas/administración & dosificación , Tamaño de la Partícula , Fármacos Fotosensibilizantes/administración & dosificación , Tecnología Farmacéutica

RESUMEN

INTRODUCTION: Photodynamic therapy (PDT) is a relatively new method of treating skin cancers. This prospective study highlights the use of PDT in the management of basal cell carcinomas (BCCs) and T1N0 cutaneous squamous cell carcinomas (SCCs) involving the periorbital area. MATERIALS AND METHODS: Surface illumination PDT was offered under local anaesthesia. mTHPC was administered intravenously. A single-channel 652 nm diode laser was used for illumination, and light was delivered at 20 J/cm2 per site. Lesion response evaluation was carried out according to response evaluation criteria in solid tumours (RECIST). RESULTS: After the first round of treatment, all cutaneous T1N0 SCC patients had complete response (CR) and continued to be in remission until last clinic review. For BCC patients, 12/14 patients had CR. The two remaining patients underwent a second round of treatment and also achieved a CR. All BCC patients were in remission at the last clinic review. Using visual analogue scale (VAS), 15 patients reported that this treatment gave them "excellent" cosmetic outcome (VAS 9-10). CONCLUSION: Photodynamic therapy achieved high efficacy in the treatment of periorbital BCCs and cutaneous SCCs with greatly reduced morbidity and disfigurement.

Asunto(s)

Carcinoma Basocelular/tratamiento farmacológico , Carcinoma de Células Escamosas/tratamiento farmacológico , Mesoporfirinas/uso terapéutico , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/uso terapéutico , Administración Intravenosa , Adulto , Anciano , Femenino , Humanos , Masculino , Mesoporfirinas/administración & dosificación , Mesoporfirinas/efectos adversos , Persona de Mediana Edad , Estadificación de Neoplasias/métodos , Fotoquimioterapia/efectos adversos , Fotoquimioterapia/estadística & datos numéricos , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/efectos adversos , Estudios Prospectivos , Neoplasias Cutáneas/patología , Resultado del Tratamiento

RESUMEN

INTRODUCTION: Photodynamic therapy (PDT) is a method of treating various pathologies. In this retrospective study with prospective intent, a total of 22 patients with T1/T2 N0 cutaneous squamous cell carcinoma (SCC) were treated with intravenous mTHPC (meta-tetrahydroxyphenylchlorin) and surface illumination PDT. Comparisons with the clinical features, rate of recurrence and overall outcome were made. MATERIALS AND METHODS: Surface illumination PDT was offered under local anaesthesia. 0.05 mg/kg mTHPC was administered intravenously into the midcubital vein 48 h prior to tissue illumination. A single-channel 652 nm diode laser was used for illumination and light was delivered at 20 J/cm2 per site. Lesion response evaluation was carried out according to Response Evaluation Criteria In Solid Tumors (RECIST). RESULTS: Clinical assessment revealed that 16 patients had lesions of <2 cm in size (T1), while the rest were T2. No nodal involvement was identified in any of the patients. None of the patients had a locally recurrent lesion. During the 3-year follow-up, 20/22 patients had complete response (CR) and this was after one round of treatment. Two patients suffered from recurrent disease within 3 years of the follow-up, and they underwent surgical resection. CONCLUSION: PDT achieved high efficacy in the treatment of T1N0 cutaneous squamous cell carcinoma with greatly reduced morbidity and disfigurement. The technique is simple, can commonly be carried out in outpatient clinics, and is highly acceptable to patients.

Asunto(s)

Antineoplásicos/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Mesoporfirinas/uso terapéutico , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/uso terapéutico , Neoplasias Cutáneas/tratamiento farmacológico , Anciano , Antineoplásicos/administración & dosificación , Carcinoma de Células Escamosas/patología , Femenino , Humanos , Infusiones Intravenosas , Láseres de Semiconductores , Masculino , Mesoporfirinas/administración & dosificación , Persona de Mediana Edad , Estadificación de Neoplasias , Inducción de Remisión , Criterios de Evaluación de Respuesta en Tumores Sólidos , Estudios Retrospectivos , Neoplasias Cutáneas/patología

RESUMEN

Foscan®, a formulation comprising temoporfin dissolved in a mixture of ethanol and propylene glycol, has been approved in Europe for palliative photodynamic therapy of squamous cell carcinoma of the head and neck. During clinical and preclinical studies it was observed that considering the administration route, the drug presents a rather atypical plasma profile as plasma concentration peaks delayed. Possible explanations, as for example the formation of a drug depot or aggregation after intravenous administration, are discussed in current literature. In the present study an advanced in silico model was developed and evaluated for the detailed description of Foscan® pharmacokinetics. Therefore, in vitro release data obtained from experiments with the dispersion releaser technology investigating dissolution pressures of various release media on the drug as well as in vivo data obtained from a clinical study were included into the in silico models. Furthermore, precipitation experiments were performed in presence of biorelevant media and precipitates were analyzed by nanoparticle tracking analysis. Size analysis and particle fraction were also incorporated in this model and a sensitivity analysis was performed. An optimal description of the in vivo situation based on in vitro release and particle characterization data was achieved, as demonstrated by an absolute average fold error of 1.21. This in vitro-in vivo correlation provides an explanation for the pharmacokinetics of Foscan® in humans.

Asunto(s)

Antineoplásicos/administración & dosificación , Simulación por Computador , Mesoporfirinas/administración & dosificación , Nanopartículas , Antineoplásicos/farmacocinética , Preparaciones de Acción Retardada , Liberación de Fármacos , Etanol/química , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Humanos , Mesoporfirinas/farmacocinética , Tamaño de la Partícula , Propilenglicol/química , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Distribución Tisular

RESUMEN

Enthusiasm for photodynamic therapy (PDT) as a promising technique to eradicate various cancers has increased exponentially in recent decades. The majority of clinically approved photosensitizers are hydrophobic in nature, thus, the effective delivery of photosensitizers at the targeted site is the main hurdle associated with PDT. Temoporfin (mTHPC, medicinal product name: Foscan®), is one of the most potent clinically approved photosensitizers, is not an exception. Successful temoporfin-PDT requires nanoscale delivery systems for selective delivery of photosensitizer. Over the last 25 years, the number of papers on nanoplatforms developed for mTHPC delivery such as conjugates, host-guest inclusion complexes, lipid-and polymer-based nanoparticles and carbon nanotubes is burgeoning. However, none of them appeared to be "ultimate". The present review offers the description of different challenges and achievements in nanoparticle-based mTHPC delivery focusing on the synergetic combination of various nano-platforms to improve temoporfin delivery at all stages of biodistribution. Furthermore, the association of different nanoparticles in one nanoplatform might be considered as an advanced strategy allowing the combination of several treatment modalities.

Asunto(s)

Sistemas de Liberación de Medicamentos , Mesoporfirinas/administración & dosificación , Fotoquimioterapia/métodos , Animales , Portadores de Fármacos/química , Humanos , Mesoporfirinas/farmacocinética , Nanopartículas , Nanotubos de Carbono , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/farmacocinética , Distribución Tisular

RESUMEN

Nanoparticles (NP) have gained importance as drug delivery systems for pharmaceutical challenging drugs. Their size properties allow passive targeting of cancer tissue by exploiting the enhanced permeability and retention (EPR) effect. Furthermore, surface modifications enable an active drug targeting for diseased regions in the human body. Besides the advantages, the drug release from commonly used biodegradable NP is mostly depending on physiological circumstances. Hence, there is a need for a more controllable drug release. The use of light-responsive polymers is an innovative conception enabling a more distinct drug release by an external light stimulus. The idea provides potential for an increase in efficiency and safety of local therapies. In this study, innovative light-sensitive NP were investigated for a photodynamic therapy (PDT) of gastrointestinal tumors. Nanoparticles based on a newly developed light-responsive polycarbonate (LrPC) and poly(lactic-co-glycolic-acid) (PLGA) were loaded with the approved photosensitizer 5,10,15,20-tetrakis(m-hydroxyphenyl)chlorin (mTHPC). Mucus penetrating properties were obtained by surface PEGylation of the nanoparticles either by using LrPC in combination with a PEGylated PLA (PEG-PLA) or by a combination with PEGylated LrPC (LrPC-PEG). Cytotoxic potential in dependency of a light-induced drug release was investigated in different cytotoxicity assays. Intracellular accumulation in mucus producing colon-carcinoma cell line HT-29-MTX was analysed by HPLC and confocal laser microscopy.

Asunto(s)

Neoplasias Intestinales/tratamiento farmacológico , Mesoporfirinas , Nanopartículas , Fotoquimioterapia , Fármacos Fotosensibilizantes , Supervivencia Celular/efectos de los fármacos , Daño del ADN , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/efectos de la radiación , Células HT29 , Humanos , Luz , Mesoporfirinas/administración & dosificación , Mesoporfirinas/química , Mesoporfirinas/efectos de la radiación , Nanopartículas/administración & dosificación , Nanopartículas/química , Nanopartículas/efectos de la radiación , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/efectos de la radiación , Polímeros/administración & dosificación , Polímeros/química , Polímeros/efectos de la radiación

RESUMEN

Photodynamic therapy (PDT) is a very attractive strategy to complement or replace common cancer treatments such as radiotherapy, surgery, and chemotherapy. Some molecules have shown their efficiency as photosensitizers (PS), still many issues have to be solved such as the inherent cytotoxicity of the PS or its hydrophobic properties causing limitation in their solubility, leading to side effects. In this study, the encapsulation of an approved PS, the meso-tetra hydroxyphenylchlorine (mTHPC, Foscan®) within biocompatible and biodegradable poly(D, l-lactide-co-glycolide) acid (PLGA) NPs prepared by the nanoprecipitation method was studied. The mTHPC-loaded NPs (mTHPC ⊂ PLGA NPs) were analyzed by UV-vis spectroscopy to determine the efficiency of mTHPC encapsulation, and by dynamic light scattering (DLS) and atomic force microscopy (AFM) to determine mTHPC ⊂ PLGA NPs sizes, morphologies and surface charges. The longitudinal follow-up of mTHPC release from the NPs indicated that 50% of the encapsulated PS was retained within the NP matrix after a period of five days. Finally, the cytotoxicity and the phototoxicity of the mTHPC ⊂ PLGA NPs were determined in murine C6 glioma cell lines and compared to the ones of mTHPC alone. The studies showed a strong decrease of mTHPC cytotoxicity and an increase of mTHPC photo-cytotoxicity when mTHPC was encapsulated. In order to have a better insight of the underlying cellular mechanisms that governed cell death after mTHPC ⊂ PLGA NPs incubation and irradiation, annexin V staining tests were performed. The results indicated that apoptosis was the main cell death mechanism.

Asunto(s)

Glioma/tratamiento farmacológico , Mesoporfirinas/farmacología , Nanopartículas/química , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/farmacología , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Mesoporfirinas/administración & dosificación , Mesoporfirinas/efectos adversos , Tamaño de la Partícula , Fotoquimioterapia/efectos adversos , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/efectos adversos , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química

RESUMEN

Nanoparticles based on biodegradable polymers are well-known as approved carrier systems for a diversity of drugs. Despite their advantages, such as the option of an active drug targeting or the physicochemical protection of instable payloads, the controlled drug release often underlies intra- and interindividual influences and is therefore difficult to predict. To circumvent this limitation, the release behavior can be optimized using light-responsive materials for the nanoparticle preparation. The resulting light-responsive nanoparticles are able to release the embedded drug after an external light-stimulus, thereby increasing efficacy and safety of the therapy. In the present study light-responsive self-immolative polymers were used for the nanoparticle manufacturing. Light-responsive polycarbonates (LrPC) as well as PEGylated LrPC (LrPC-PEG) were synthesized via ring-opening polymerization of trimethylene carbonate-based monomers and fully physico-chemically characterized. Light-responsive nano formulations were obtained by blending LrPC or (LrPC-PEG) with the FDA-approved polymer poly(DL-lactide-co-glycolide) (PLGA). The nanoparticles were loaded with the photosensitizer 5,10,15,20-tetrakis(m-hydroxyphenyl)chlorin (mTHPC). The light-induced nanoparticle degradation was analyzed as well as the drug release behavior with and without illumination. Furthermore, biological safety of the degradation products was investigated in an in vitro cell culture study.

Asunto(s)

Sistemas de Liberación de Medicamentos , Luz , Mesoporfirinas/administración & dosificación , Nanopartículas , Fármacos Fotosensibilizantes/administración & dosificación , Polímeros , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Nanopartículas/administración & dosificación , Nanopartículas/efectos de la radiación , Fotoquimioterapia , Polímeros/administración & dosificación , Polímeros/efectos de la radiación

RESUMEN

Photodynamic therapy (PDT) is a treatment utilizing the combined action of photosensitizers and light for the treatment of various cancers. The mechanisms for tumor destruction after PDT include direct tumor cell kill by singlet oxygen species (OS), indirect cell kill via vascular damage, and an elicited immune response. However, it has been reported that many cellular activators, including vascular endothelial growth factor (VEGF), are produced by tumor cells after PDT. In this study, we demonstrate that meta-tetra(hydroxyphenyl) chlorin (mTHPC)-based photodynamic therapy combined with bevacizumab (Avastin™), an anti-VEGF neutralizing monoclonal antibody that blocks the binding of VEGF to its receptor, can enhance the effectiveness of each treatment modality. We evaluated the efficacy of bevacizumab-based anti-angiogenesis in combination with PDT as well as the resulting VEGF levels and microvessel density (MVD) in a mouse model of human colon cancer. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) were performed to assess VEGF concentrations and microvessel density in the various treatment groups, and confocal imaging and high performance liquid chromatography (HPLC) analyses were used to measure the distribution and concentration of mTHPC in tumors. Our results demonstrate that combination of PDT followed by bevacizumab significantly elicits a greater tumor response whereas bevacizumab treatment prior to PDT led to a reduced tumor response. Immunostaining and ELISA analyses revealed a lower expression of VEGF in tumors treated with combination therapy of PDT followed by bevacizumab. However, bevacizumab treatment decreased the accumulation of mTHPC in tumors 24 h after administration, which complemented the results of decreased anti-tumor efficacy of bevacizumab followed by PDT.

Asunto(s)

Inhibidores de la Angiogénesis/farmacología , Bevacizumab/farmacología , Neoplasias Colorrectales/tratamiento farmacológico , Mesoporfirinas/farmacología , Fármacos Fotosensibilizantes/farmacología , Animales , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Ensayo de Inmunoadsorción Enzimática , Femenino , Estimación de Kaplan-Meier , Mesoporfirinas/administración & dosificación , Ratones , Ratones Endogámicos BALB C , Neovascularización Patológica/tratamiento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/administración & dosificación , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Carga Tumoral , Factor A de Crecimiento Endotelial Vascular/metabolismo

RESUMEN

BACKGROUND: Drug targeting using functionalized nanoparticles to advance their transport to the dedicated site became a new standard in novel anticancer methods Anticancer photodynamic therapy also takes benefit from using nanoparticles by means of increasing targeting efficiency and decreased side effect. With this in mind, the silica-based nanoparticles, as drug delivery systems for the second-generation photosensitizer 5,10,15,20-tetrakis(m-hydroxyphenyl) chlorin (temoporfin) were developed. METHODS: In order to determine the stability and therapeutic performance of the selected nanomaterials in physiological fluids, their physicochemical properties (i.e. size, polydispersity, zeta potential) were measured by dynamic light scattering technique and the diameter and the morphology of the individual particles were visualized by a transmission electron microscopy. Their efficacy was compared with commercial temoporfin formulation in terms of in vitro phototoxicity in 4T1 (murine mammary carcinoma) and of in vivo anticancer effect in Nu/Nu mice bearing MDA-MB-231 tumors. RESULTS AND CONCLUSIONS: The two types of silica nanoparticles, porous and non-porous and with different surface chemical modification, were involved and critically compared within the study. Their efficacy was successfully demonstrated and was shown to be superior in comparison with commercial temoporfin formulation in terms of in vitro phototoxicity and cellular uptake as well as in terms of in vivo anticancer effect on human breast cancer model. Temoporfin-loaded silica nanoparticles also passed through the blood-brain barrier showing potential for the treatment of brain metastases.

Asunto(s)

Mesoporfirinas/administración & dosificación , Nanopartículas/química , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/administración & dosificación , Dióxido de Silicio/química , Animales , Línea Celular Tumoral , Portadores de Fármacos/química , Liberación de Fármacos , Humanos , Mesoporfirinas/farmacología , Ratones Desnudos , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Fármacos Fotosensibilizantes/farmacología , Polietilenglicoles/química

RESUMEN

Efficient photodynamic therapy with meta-tetra(hydroxyphenyl)chlorine requires the application of specific nanoformulations. mTHPC liposomal formulation (Foslip®) demonstrated favorable pharmacokinetics properties. However, rapid liposomes destruction in circulation and rapid mTHPC release impedes Foslip® applications. Alternatively, mTHPC nanovectorization using extracellular vesicles (EVs) could be an attractive option. EVs are naturally secreted by the organism to play a role in intercellular communication due to the capacity to transport proteins and nucleic acids. EVs also possess a natural ability to deliver therapeutic molecules into cancer cells. The aim of the present study was to evaluate photophysical and photobiological properties of mTHPC loaded in endothelial EVs as nanocarriers. We also studied efficiency of nanovectorisation on mTHPC distribution and PDT activity in multicellular tumor spheroids (MCTSs). MCTS is a nonvascularized in vitro 3D model of cells that mimics a similar microenvironment to in vivo situation. mTHPC-EVs were characterized by means of spectroscopic techniques, flow cytometry and nanoparticle tracking analysis. Compared with Foslip®, mTHPC-EVs are stable in murine plasma. Better mTHPC accumulation and penetration (up to 100 µm) in MCTS was observed for mTHPC-EVs compared with liposomal mTHPC. These factors could explain enhanced photodynamic activity of mTHPC-EVs compared with free and liposomal mTHPC. The light dose inducing 50% of cell death with mTHPC-EVs was 4 and 2.5-times lower than that of free and liposomal mTHPC. The obtained results demonstrate that EVs should be considered as perspective nanocarriers for mTHPC-mediated PDT.

Asunto(s)

Antineoplásicos/administración & dosificación , Apoptosis/efectos de los fármacos , Vesículas Extracelulares , Liposomas , Mesoporfirinas/administración & dosificación , Esferoides Celulares/efectos de los fármacos , Portadores de Fármacos , Estabilidad de Medicamentos , Vesículas Extracelulares/ultraestructura , Células HT29 , Células Endoteliales de la Vena Umbilical Humana , Humanos , Técnicas In Vitro , Liposomas/ultraestructura , Microscopía Confocal , Nanopartículas , Fotoquimioterapia/métodos , Esferoides Celulares/ultraestructura , Células Tumorales Cultivadas

RESUMEN

Selective elimination of macrophages by photodynamic therapy (PDT) is a new and promising therapeutic modality for the reduction of atherosclerotic plaques. m-Tetra(hydroxyphenyl)chlorin (mTHPC, or Temoporfin) may be suitable as photosensitizer for this application, as it is currently used in the clinic for cancer PDT. In the present study, mTHPC was encapsulated in polymeric micelles based on benzyl-poly(ε-caprolactone)-b-methoxy poly(ethylene glycol) (Ben-PCL-mPEG) using a film hydration method, with loading capacity of 17%. Because of higher lipase activity in RAW264.7 macrophages than in C166 endothelial cells, the former cells degraded the polymers faster, resulting in faster photosensitizer release and higher in vitro photocytotoxicity of mTHPC-loaded micelles in those macrophages. However, we observed release of mTHPC from the micelles in 30min in blood plasma in vitro which explains the observed similar in vivo pharmacokinetics of the mTHPC micellar formulation and free mTHPC. Therefore, we could not translate the beneficial macrophage selectivity from in vitro to in vivo. Nevertheless, we observed accumulation of mTHPC in atherosclerotic lesions of mice aorta's which is probably the result of binding to lipoproteins upon release from the micelles. Therefore, future experiments will be dedicated to increase the stability and thus allow accumulation of intact mTHPC-loaded Ben-PCL-mPEG micelles to macrophages of atherosclerotic lesions.

Asunto(s)

Enfermedades Cardiovasculares/tratamiento farmacológico , Mesoporfirinas/administración & dosificación , Micelas , Fármacos Fotosensibilizantes/administración & dosificación , Animales , Enfermedades Cardiovasculares/metabolismo , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Células Endoteliales/efectos de la radiación , Femenino , Luz , Mesoporfirinas/sangre , Mesoporfirinas/farmacocinética , Mesoporfirinas/uso terapéutico , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Desnudos , Fotoquimioterapia , Fármacos Fotosensibilizantes/sangre , Fármacos Fotosensibilizantes/farmacocinética , Fármacos Fotosensibilizantes/uso terapéutico , Poliésteres/administración & dosificación , Poliésteres/farmacocinética , Poliésteres/uso terapéutico , Células RAW 264.7 , Oxígeno Singlete/química , Distribución Tisular

RESUMEN

The development of drug resistance is a major problem which often occurs during anticancer chemotherapies. Photodynamic therapy (PDT) has been studied as an alternative treatment modality for drug-resistant tumors, however the question of resistance to PDT and potential cross-resistance with chemotherapy has yet to be fully answered. To investigate the mechanism of resistance to PDT, we developed an in vitro experimental model system in a mouse mammary carcinoma cell line 4T1. We used two ethylene glycol derivatives of tetraphenylporphyrin, and tetraphenylchlorin derivative, temoporfin, as photosensitizers (PS). PDT-resistant clones were obtained by exposure to a set concentration of PS followed by irradiation with increasing light doses. PDT resistance to soluble glycol porphyrins was mediated mainly by increased drug efflux through ABCB1 (P-glycoprotein) as we demonstrated by specific ABCB1 knockdown experiments, which in turn rescued the sensitivity of resistant cells to PDT. In contrast, resistance raised to temoporfin, which is generally more lipophilic than glycol porphyrins, elicited mechanism based on sequestration of the drug to lysosomes. The resistance that is acquired from a particular PS could be overcome by using a different PS, which is not susceptible to the same mechanism(s) of resistance. Elucidation of the underlying mechanisms in various types of resistance might facilitate improvements in PDT treatment design.

Asunto(s)

Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Resistencia a Antineoplásicos/genética , Neoplasias Mamarias Animales/tratamiento farmacológico , Mesoporfirinas/administración & dosificación , Animales , Glicoles de Etileno/administración & dosificación , Glicoles de Etileno/química , Femenino , Técnicas de Silenciamiento del Gen , Glicoles/química , Humanos , Células MCF-7 , Neoplasias Mamarias Animales/genética , Neoplasias Mamarias Animales/patología , Mesoporfirinas/química , Ratones , Paclitaxel/efectos adversos , Fotoquimioterapia , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/química , Porfirinas/administración & dosificación , Porfirinas/química

RESUMEN

BACKGROUND: Photosensitizers are used in photodynamic therapy (PDT) to destruct tumor cells, however, their limited solubility and specificity hampers routine use, which may be overcome by encapsulation. Several promising novel nanoparticulate drug carriers including liposomes, polymeric nanoparticles, metallic nanoparticles and lipid nanocomposites have been developed. However, many of them contain components that would not meet safety standards of regulatory bodies and due to difficulties of the manufacturing processes, reproducibility and scale up procedures these drugs may eventually not reach the clinics. Recently, we have designed a novel lipid nanostructured carrier, namely Lipidots, consisting of nontoxic and FDA approved ingredients as promising vehicle for the approved photosensitizer m-tetrahydroxyphenylchlorin (mTHPC). RESULTS: In this study we tested Lipidots of two different sizes (50 and 120 nm) and assessed their photodynamic potential in 3-dimensional multicellular cancer spheroids. Microscopically, the intracellular accumulation kinetics of mTHPC were retarded after encapsulation. However, after activation mTHPC entrapped into 50 nm particles destroyed cancer spheroids as efficiently as the free drug. Cell death and gene expression studies provide evidence that encapsulation may lead to different cell killing modes in PDT. CONCLUSIONS: Since ATP viability assays showed that the carriers were nontoxic and that encapsulation reduced dark toxicity of mTHPC we conclude that our 50 nm photosensitizer carriers may be beneficial for clinical PDT applications.

Asunto(s)

Mesoporfirinas/farmacología , Fotoquimioterapia/métodos , Esferoides Celulares/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Portadores de Fármacos/administración & dosificación , Emulsiones/farmacología , Humanos , Lípidos/química , Ensayo de Materiales , Mesoporfirinas/administración & dosificación , Nanopartículas/química , Tamaño de la Partícula , Esferoides Celulares/efectos de la radiación , Células Tumorales Cultivadas

RESUMEN

Nanogels offer many unique features rendering them as very attractive candidates for drug delivery. However, for their applications the loading capacity and specific encapsulation, in particular for hydrophobic drugs, in a complex media are two critical factors. In this work, we report for the first time on the preparation of nanogel-peptide conjugates with the ability of specific encapsulation of temoporfin (m-THPC). The peptide was selected based on combinatorial means and it was conjugated to polyglycerol as the nanogel precursor. We observed that the loading capacity of nanogels improved 16 times upon peptide conjugation. Skin penetrations tests in barrier deficient skin showed that nanogel-peptide conjugates enhance the penetration of m-THPC in the viable skin layers efficiently. This study indicates that nanogel-peptide conjugates could be used as unique carriers with high loading capacity for hydrophobic compounds, which provides the basis for the design of advanced topical drug delivery systems.

Asunto(s)

Sistemas de Liberación de Medicamentos , Mesoporfirinas/administración & dosificación , Nanopartículas , Absorción Cutánea , Administración Cutánea , Portadores de Fármacos/química , Glicerol/química , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Mesoporfirinas/farmacocinética , Péptidos/química , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/farmacocinética , Polímeros/química

RESUMEN

We and others have shown that stresses, including photodynamic therapy (PDT), can disrupt the de novo sphingolipid biosynthesis pathway, leading to changes in the levels of sphingolipids, and subsequently, modulation of cell death. The de novo sphingolipid biosynthesis pathway includes a ceramide synthase-dependent reaction, giving rise to dihydroceramide, which is then converted in a desaturase-dependent reaction to ceramide. In this study we tested the hypothesis that combining Foscan-mediated PDT with desaturase inhibitor fenretinide (HPR) enhances cancer cell killing. We discovered that by subjecting SCC19 cells, a human head and neck squamous cell carcinoma cell line, to PDT+HPR resulted in enhanced accumulation of C16-dihydroceramide, not ceramide. Concomitantly, mitochondrial depolarization was enhanced by the combined treatment. Enhanced activation of caspase-3 after PDT+HPR was inhibited by FB. Enhanced clonogenic cell death after the combination was sensitive to FB, as well as Bcl2- and caspase inhibitors. Treatment of mouse SCCVII squamous cell carcinoma tumors with PDT+HPR resulted in improved long-term tumor cures. Overall, our data showed that combining PDT with HPR enhanced apoptotic cancer cell killing and antitumor efficacy of PDT. The data suggest the involvement of the de novo sphingolipid biosynthesis pathway in enhanced apoptotic cell killing after PDT+HPR, and identify the combination as a novel more effective anticancer treatment than either treatment alone.

Asunto(s)

Apoptosis , Fenretinida/uso terapéutico , Mesoporfirinas/uso terapéutico , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Esfingolípidos/biosíntesis , Línea Celular Tumoral , Quimioterapia Combinada , Fenretinida/administración & dosificación , Humanos , Mesoporfirinas/administración & dosificación , Fármacos Fotosensibilizantes/administración & dosificación

RESUMEN

Online light dosimetry with real-time feedback was applied for temoporfin-mediated interstitial photodynamic therapy (PDT) of dog prostate. The aim was to investigate the performance of online dosimetry by studying the correlation between light dose plans and the tissue response, i.e., extent of induced tissue necrosis and damage to surrounding organs at risk. Light-dose planning software provided dose plans, including light source positions and light doses, based on ultrasound images. A laser instrument provided therapeutic light and dosimetric measurements. The procedure was designed to closely emulate the procedure for whole-prostate PDT in humans with prostate cancer. Nine healthy dogs were subjected to the procedure according to a light-dose escalation plan. About 0.15 mg/kg temoporfin was administered 72 h before the procedure. The results of the procedure were assessed by magnetic resonance imaging, and gross pathology and histopathology of excised tissue. Light dose planning and online dosimetry clearly resulted in more focused effect and less damage to surrounding tissue than interstitial PDT without dosimetry. A light energy dose-response relationship was established where the threshold dose to induce prostate gland necrosis was estimated from 20 to 30 J/cm2.

Asunto(s)

Mesoporfirinas , Fotoquimioterapia , Fármacos Fotosensibilizantes , Próstata , Radioterapia Asistida por Computador/métodos , Animales , Perros , Relación Dosis-Respuesta en la Radiación , Masculino , Mesoporfirinas/administración & dosificación , Mesoporfirinas/efectos adversos , Necrosis , Fotoquimioterapia/efectos adversos , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/efectos adversos , Próstata/efectos de los fármacos , Próstata/patología , Próstata/efectos de la radiación

RESUMEN

PURPOSE: In the present study we introduce an efficient approach for a size-based separation of liposomes from plasma proteins employing AF4. We investigated vesicle stability and release behavior of the strongly lipophilic drug temoporfin from liposomes in human plasma for various incubation times at 37°C. METHODS: We used the radioactive tracer cholesteryl oleyl ether (COE) or dipalmitoyl-phosphocholine (DPPC) as lipid markers and (14)C-labeled temoporfin. First, both lipid labels were examined for their suitability as liposome markers. Furthermore, the influence of plasma origin on liposome stability and drug transfer was investigated. The effect of membrane fluidity and PEGylation on vesicle stability and drug release characteristics was also analyzed. RESULTS: Surprisingly, we observed an enzymatic transfer of (3)H-COE to lipoproteins due to the cholesterol ester transfer protein (CETP) in human plasma in dependence on membrane rigidity and were able to inhibit this transfer by plasma preincubation with the CETP inhibitor torcetrapib. This effect was not seen when liposomes were incubated in rat plasma. DPPC labels suffered from hydrolysis effects during preparation and/or storage. Fluid liposomes were less stable in human plasma than their PEGylated analogues or a rigid formulation. In contrast, the transfer of the incorporated drug to lipoproteins was higher for the rigid formulations. CONCLUSIONS: The observed effects render COE-labels questionable for in vivo studies using CEPT-rich species. Here, choline labelled (14)C-DPPC was found to be the most promising alternative. Bilayer composition has a high influence on stability and drug release of a liposomal formulation in human plasma.

Asunto(s)

Antineoplásicos/administración & dosificación , Fraccionamiento de Campo-Flujo/métodos , Liposomas/química , Mesoporfirinas/administración & dosificación , Animales , Antineoplásicos/sangre , Proteínas Sanguíneas/aislamiento & purificación , Colesterol/análogos & derivados , Colesterol/química , Liberación de Fármacos , Humanos , Liposomas/aislamiento & purificación , Masculino , Mesoporfirinas/sangre , Fosfolípidos/química , Polietilenglicoles/química , Ratas Wistar

RESUMEN

BACKGROUND: Photodynamic therapy (PDT) in combination with stent have shown promising results in the treatment of biliary tract cancer (BTC) in patients not suitable for surgery. Chemotherapy has been shown to improve survival in patients with local advanced and metastatic BTC. MATERIAL AND METHODS: In the current randomized trial the combination of chemotherapy and stent with and without temoporfin (Foscan) photodynamic therapy (PDT), with a primary endpoint on feasibility and safety, has been performed. Ten patients in each group. RESULTS: No serious, acute procedure-related complication related to PDT or the treatment combination was seen. The number of patients with cholangitis was equal in both groups. In the PDT group--arm A--two patients had cutaneous erythema after sun exposition, one of them with a localized blister. No neutropenic infection was seen. Quality of Life (QoL) was similar in both treatment groups. Progression free survival was numerically longer in the PDT group. CONCLUSION: The treatment combination was feasible. There was no serious complication related to PDT or the treatment combination. Number of cholangitis was equal in both groups, two abscesses were observed in the PDT group. Progression free survival was numerically longer in the PDT group.

Asunto(s)

Antineoplásicos/uso terapéutico , Neoplasias del Sistema Biliar/tratamiento farmacológico , Mesoporfirinas/administración & dosificación , Fotoquimioterapia/métodos , Stents , Adulto , Anciano , Terapia Combinada/métodos , Supervivencia sin Enfermedad , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fármacos Fotosensibilizantes/administración & dosificación , Resultado del Tratamiento

RESUMEN

The aim of the present investigation was to develop a reliable method which can be applied to the measurement of in vitro drug release from nanocarriers. Since the limited membrane transport is one major obstacle to the assessment of drug release with dialysis techniques, the determination of this parameter was our objective. Therefore, a novel drug release automatic monitoring system (DREAMS) was designed to conduct continuous measurements during the dialysis process. Moreover, a mathematical model was used for evaluation of the experimental data. This combination of mathematical and analytical tools enabled the quantification of the total amount of free drug in the system. Eudragit(®) RS 100 nanoparticles loaded with the model compound 5,10,15,20-tetrakis(m-hydroxypheny)chlorin (mTHPC) were investigated and the drug release was continuously monitored by using a fluorescence spectrometer that is part of the setup. Free drug and drug-loaded nanoparticles were tested to discriminate between the two formulations. In addition, two types of membranes composed of different materials were evaluated and the kinetics of membrane transport was determined. The data obtained from the apparatus were further treated by a mathematical model, which yielded distinguishable release profiles between samples of different compositions. The method offers a promising option for release testing of nanoparticles.

Asunto(s)

Química Farmacéutica/métodos , Diálisis/métodos , Portadores de Fármacos/química , Modelos Teóricos , Nanopartículas/química , Antineoplásicos/administración & dosificación , Liberación de Fármacos , Mesoporfirinas/administración & dosificación , Espectrometría de Fluorescencia