RESUMO
In recent years, there has been an increasing recognition of the unique healthcare needs of gender-diverse patients in Australia. With the continuous growth of referrals to gender health services, there is an increased demand for specialised dermatological care. There is still a significant knowledge gap and a lack of guidelines specifically tailored to this patient group. In this article, we will provide a brief overview of the journey of Transgender and Gender Diverse (TGD) individuals as they embark on psychological and pharmacologic treatment for gender dysphoria in Australia. We endeavour to contribute to the existing body of knowledge by examining the evidence surrounding the treatment of skin, hair and nail issues for TGD patients. This article will outline how dermatologists can assist in the care of the gender-diverse patient. Although puberty blockade (stage 1 treatments) has minimal dermatological impact, gender-affirming pharmacotherapy (stage 2 treatments) can lead to many dermatological issues including acne, patterned hair loss (PHL) and dermatitis. The dermatologist may also play a role in stage 3 treatments which include surgical or procedural interventions for gender affirmation.
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Three-dimensional (3D) spheroid models are crucial for cancer research, offering more accurate insights into tumour biology and drug responses than traditional 2D cell cultures. However, inconsistent and low-throughput spheroid production has hindered their application in drug screening. Here, we present an automated high-throughput platform for a spheroid selection, fabrication, and sorting system (SFSS) to produce uniform gelatine-encapsulated spheroids (GESs) with high efficiency. SFSS integrates advanced imaging, analysis, photo-triggered fabrication, and microfluidic sorting to precisely control spheroid size, shape, and viability. Our data demonstrate that our SFSS can produce over 50 GESs with consistent size and circularity in 30 min with over 97% sorting accuracy while maintaining cell viability and structural integrity. We demonstrated that the GESs can be used for drug screening and potentially for various assays. Thus, the SFSS could significantly enhance the efficiency of generating uniform spheroids, facilitating their application in drug development to investigate complex biological systems and drug responses in a more physiologically relevant context.
Assuntos
Ensaios de Triagem em Larga Escala , Esferoides Celulares , Humanos , Avaliação Pré-Clínica de Medicamentos , Sobrevivência Celular , Ensaios de Seleção de Medicamentos Antitumorais , Linhagem Celular Tumoral , Técnicas de Cultura de CélulasRESUMO
An acetal-linked dimeric phthalocyanine has been synthesised and immobilised on the surface of gold nanobipyramids. The resulting nanocomposite serves as a highly sensitive probe for intracellular pH through its acid-responsive fluorescence and surface-enhanced Raman scattering signals. The phthalocyanine units released in the acidic intracellular environment can also effectively eliminate the cancer cells upon light irradiation, rendering this simple fabricated nanosystem a bimodal and bifunctional theranostic agent.
Assuntos
Ouro , Indóis , Isoindóis , Fotoquimioterapia , Indóis/química , Indóis/efeitos da radiação , Ouro/química , Humanos , Concentração de Íons de Hidrogênio , Fotoquimioterapia/métodos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/efeitos da radiação , Análise Espectral Raman/métodos , Neoplasias , Dimerização , Linhagem Celular TumoralRESUMO
Two dual stimuli-activated photosensitizers were developed, in which two or three glutathione (GSH)-responsive 2,4-dinitrobenzenesulfonate (DNBS)-substituted zinc(II) phthalocyanine units were connected via one or two cathepsin B-cleavable Gly-Phe-Leu-Gly peptide linker(s). These dimeric and trimeric phthalocyanines were fully quenched in the native form due to the photoinduced electron transfer to the DNBS substituents and the self-quenching of the phthalocyanine units. In the presence of GSH and cathepsin B, or upon internalization into A549 and HepG2 cancer cells, these probes were activated through the release of free phthalocyanine units. The intracellular fluorescence intensity was increased upon post-incubation with GSH ester or reduced upon pre-treatment with a cathepsin B inhibitor. Upon light irradiation, these photosensitizers became highly cytotoxic with IC50 values of 0.21-0.39 µM. The photocytotoxicity was also dependent on the intracellular GSH and cathepsin B levels. The results showed that these conjugates could serve as smart photosensitizers for targeted photodynamic therapy.
Assuntos
Antineoplásicos/farmacologia , Biopolímeros/metabolismo , Catepsina B/metabolismo , Glutationa/metabolismo , Isoindóis/metabolismo , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Linhagem Celular Tumoral , Fluorescência , HumanosRESUMO
BACKGROUND: We report herein the synthesis of a novel dicationic boron dipyrromethene derivative (compound 3) which is symmetrically substituted with two trimethylammonium styryl groups. METHODS: The antibacterial photodynamic activity of compound 3 was determined against sixteen methicillin-resistant Staphylococcus aureus (MRSA) strains, including four ATCC type strains (ATCC 43300, ATCC BAA-42, ATCC BAA-43, and ATCC BAA-44), two mutant strains [AAC(6')-APH(2") and RN4220/pUL5054], and ten nonduplicate clinical strains of hospital- and community-associated MRSA. Upon light irradiation, the minimum bactericidal concentrations of compound 3 were in the range of 1.56-50 µM against all the sixteen MRSA strains. Interestingly, compound 3 was not only more active than an analogue in which the ammonium groups are not directly connected to the n-conjugated system (compound 4), but also showed significantly higher (p < 0.05) antibacterial potency than the clinically approved photosensitizer methylene blue. The skin irritation of compound 3 during topical application was tested on human 3-D skin constructs and proven to be non-irritant in vivo at concentrations below 1.250 mM. In the murine MRSA infected wound study, the colony forming unit reduction of compound 3 + PDT group showed significantly (p < 0.05) higher value (>2.5 log10) compared to other test groups except for the positive control. CONCLUSION: In conclusion, the present study provides a scientific basis for future development of compound 3 as a potent photosensitizer for photodynamic therapy for MRSA wound infection.
Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Fotoquimioterapia , Animais , Antibacterianos/farmacologia , Boro , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Fármacos Fotossensibilizantes/uso terapêutico , Porfobilinogênio/análogos & derivadosRESUMO
By using an oil-in-water single emulsion method, a series of multifunctional hybrid nanoparticles (NPs) were prepared which consisted of a core of poly(lactic-co-glycolic acid) (PLGA) with a lipoid shell of n-hexadecylamine-substituted hyaluronic acid (HA), encapsulating a zinc(II) phthalocyanine-based photosensitizer (ZnPc). As determined by laser light scattering, these hybrid NPs labeled as ZnPc@PLGA-HA NPs possessed a hydrodynamic diameter of 280 nm and a surface charge of -30 mV, showing high stability in serum. The Q-band absorption of ZnPc exhibited a large red-shift from 674 nm for free ZnPc in dimethylsulfoxide to 832 nm for this nanosystem in water. Upon light irradiation at 808 nm, the encapsulated ZnPc induced a strong photothermal effect instead of photodynamic action, which is usually observed for ZnPc-containing NPs. The tumor-targeting effect of these NPs due to the HA coating was investigated against the human colorectal adenocarcinoma HT29 cells and human lung carcinoma A549 cells, both of which overexpress cluster determinant 44 (CD44) receptors, using the CD44-negative human normal hepatic LO2 cells as a negative control. The photothermal cell-killing effect of these NPs was significantly higher for the two CD44-positive cell lines than that for the negative control. Their in vivo photothermal efficacy was also examined on HT29 tumor-bearing nude mice. Upon irradiation, the NPs caused significant temperature increase at the tumor site and ablation of the tumor. The results showed that these multifunctional NPs could serve as an effective photothermal agent for targeted photothermal therapy. Statement of significance Phthalocyanines are well-known photosensitizers for photodynamic therapy. By encapsulating these molecules into various nanoplatforms, a range of multifunctional photosensitizing systems have been developed for cancer therapy. In this study, we have demonstrated that by careful selection of phthalocyanines and the nanocarriers, as well as the self-assembly and encapsulation methods, the encapsulated phthalocyanine molecules could switch the photoinduced action from photodynamic therapy to photothermal therapy as a result of the enhanced aggregation of the macrocyclic molecules in the nanoparticles. The unique packing of the molecules also resulted in a large red-shift of the Q-band absorption to 832 nm, facilitating the in vitro and in vivo photothermal treatment.
Assuntos
Nanopartículas , Fotoquimioterapia , Animais , Linhagem Celular Tumoral , Glicóis , Ácido Hialurônico/farmacologia , Indóis , Isoindóis , Camundongos , Camundongos Nus , Compostos Organometálicos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Zinco , Compostos de ZincoRESUMO
A phthalaldehyde-substituted phthalocyanine has been synthesized that can conjugate with a range of biomolecules, including peptides, monosaccharides, lipids, and DNAs, and be immobilized on the surface of bovine serum album nanoparticles and glass slides using the versatile and efficient phthalaldehyde-amine capture reactions. The light-induced cytotoxic effects of the latter two materials have also been examined against cancer cells and bacteria, respectively, showing that they are highly efficient photosensitizing systems for photodynamic therapy.
RESUMO
COVID-19, caused by SARS-CoV-2, is a virulent pneumonia, with >4,000,000 confirmed cases worldwide and >290,000 deaths as of May 15, 2020. It is critical that vaccines and therapeutics be developed very rapidly. Mice, the ideal animal for assessing such interventions, are resistant to SARS-CoV-2. Here, we overcome this difficulty by exogenous delivery of human ACE2 with a replication-deficient adenovirus (Ad5-hACE2). Ad5-hACE2-sensitized mice developed pneumonia characterized by weight loss, severe pulmonary pathology, and high-titer virus replication in lungs. Type I interferon, T cells, and, most importantly, signal transducer and activator of transcription 1 (STAT1) are critical for virus clearance and disease resolution in these mice. Ad5-hACE2-transduced mice enabled rapid assessments of a vaccine candidate, of human convalescent plasma, and of two antiviral therapies (poly I:C and remdesivir). In summary, we describe a murine model of broad and immediate utility to investigate COVID-19 pathogenesis and to evaluate new therapies and vaccines.
Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/prevenção & controle , Modelos Animais de Doenças , Pandemias/prevenção & controle , Pneumonia Viral/patologia , Pneumonia Viral/prevenção & controle , Vacinação , Enzima de Conversão de Angiotensina 2 , Animais , COVID-19 , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Humanos , Interferon gama/genética , Interferon gama/metabolismo , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/virologia , Receptor de Interferon alfa e beta/genética , Receptor de Interferon alfa e beta/metabolismo , SARS-CoV-2 , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Organismos Livres de Patógenos Específicos , Transdução Genética , Células Vero , Carga Viral , Replicação ViralRESUMO
Antimicrobial photodynamic therapy (aPDT) is an innovative approach to combat multi-drug resistant bacteria. It is known that cationic Zn(II) phthalocyanines (ZnPc) are effective in mediating aPDT against methicillin-resistant Staphylococcus aureus (MRSA). Here we used ZnPc-based photosensitizer named ZnPcE previously reported by our research group to evaluate its aPDT efficacy against broad spectrum of clinically relevant MRSAs. Remarkably, in vitro anti-MRSA activity was achieved using near-infrared (NIR, >610â nm) light with minimal bactericidal concentrations ranging <0.019-0.156â µM against the panel of MRSAs. ZnPcE was not only significantly (p < .05) more potent than methylene blue, which is a clinically approved photosensitizer but also demonstrated low cytotoxicity against human fibroblasts cell line (Hs-27) and human immortalized keratinocytes cell line (HaCaT). The toxicity was further evaluated on human 3-D skin constructs and found ZnPcE did not manifest in vivo skin irritation at ≤7.8â µM concentration. In the murine MRSA wound model, ZnPcE with PDT group demonstrated > 4 log10 CFU reduction and the value is significantly higher (p < .05) than all test groups except positive control. To conclude, results of present study provide a scientific basis for future clinical evaluation of ZnPcE-PDT on MRSA wound infection.
Assuntos
Indóis/administração & dosagem , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Compostos Organometálicos/administração & dosagem , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Infecções Estafilocócicas/tratamento farmacológico , Administração Tópica , Animais , Linhagem Celular , Modelos Animais de Doenças , Humanos , Indóis/química , Indóis/farmacologia , Isoindóis , Masculino , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Compostos de ZincoRESUMO
A series of cationic boron dipyrromethene (BODIPY) derivatives were synthesized and characterized with various spectroscopic methods. Having the ability to generate singlet oxygen upon irradiation, these compounds could potentially serve as photosensitizers for antimicrobial photodynamic therapy. Of the five BODIPYs being examined, the dicationic aza-BODIPY analogue (compound 5) demonstrated the highest potency against a broad spectrum of clinically relevant methicillin-resistant Staphylococcus aureus (MRSA), including four ATCC-type strains (ATCC 43300, ATCC BAA-42, ATCC BAA-43, and ATCC BAA-44), two strains carrying specific antibiotic resistance mechanisms [-AAC(6')-APH(2") and RN4220/pUL5054], and ten non-duplicate clinical strains from hospital- and community-associated MRSAs of the important clonal types ST239, ST30, and ST59, which have previously been documented to be prevalent in Hong Kong and its neighboring countries. The in vitro anti-MRSA activity of compound 5 was achieved upon irradiation with near-infrared light (>610 nm) with minimal bactericidal concentrations (MBCs) ranging from 12.5 to 25 µM against the whole panel of MRSAs, except the hospital-associated MRSAs for which the MBCs were in the range of 50-100 µM. Compound 5 was significantly (p < 0.05) more potent than methylene blue, which is a clinically approved photosensitizer, indicating that it is a promising antimicrobial agent that is worthy of further investigation.
RESUMO
A combined stimulus-responsive photosensitiser and drug release system based on mesoporous silica nanoparticles was prepared. This nanoplatform encapsulated molecules of zinc(ii) phthalocyanine substituted with a glutathione-cleavable 2,4-dinitrobenzenesulfonate quencher and doxorubicin linked via a singlet-oxygen-cleavable 9,10-dialkoxyanthracene linker. In the presence of glutathione (in mM range) and upon irradiation (λ > 610 nm), the phthalocyanine units were activated by detaching from the quenching component to emit fluorescence and generate singlet oxygen. The latter subsequently cleaved the 9,10-dialkoxyanthracene linker to trigger the release of a doxorubicin derivative. The glutathione- and light-controlled activation and drug-release processes on this nanoplatform were demonstrated in phosphate buffered saline. The activation in fluorescence emission by intracellular thiols was also shown inside HepG2 human hepatocellular carcinoma cells. Upon irradiation, the nanosystem exhibited high cytotoxicity due to the photodynamic effect of the activated phthalocyanine units, but the cytotoxic effect of the released Dox moieties was not notable probably due to their reduced cytotoxicity as a result of the pendant substituent and the low drug loading in the nanoparticles.
Assuntos
Preparações de Ação Retardada/metabolismo , Glutationa/metabolismo , Indóis/metabolismo , Nanopartículas/metabolismo , Compostos Organometálicos/metabolismo , Dióxido de Silício/metabolismo , Oxigênio Singlete/metabolismo , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/farmacologia , Benzenossulfonatos/metabolismo , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Células Hep G2 , Humanos , Isoindóis , Luz , Porosidade , Compostos de ZincoRESUMO
A boron dipyrromethene based photosensitiser substituted with a 1,2,4,5-tetrazine moiety has been prepared of which the photoactivity can be activated upon an inverse-electron-demand Diels-Alder reaction with trans-cyclooctene derivatives. By using a biotin-conjugated trans-cyclooctene to tag the biotin-receptor-positive HeLa cells, this photosensitiser exhibits site-specific activation through cycloaddition, leading to high photocytotoxicity.
Assuntos
Compostos de Boro/farmacologia , Compostos Heterocíclicos com 1 Anel/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/efeitos da radiação , Biotina/análogos & derivados , Biotina/síntese química , Biotina/farmacologia , Compostos de Boro/síntese química , Compostos de Boro/efeitos da radiação , Linhagem Celular Tumoral , Reação de Cicloadição , Ciclo-Octanos/síntese química , Ciclo-Octanos/química , Ciclo-Octanos/farmacologia , Compostos Heterocíclicos com 1 Anel/síntese química , Compostos Heterocíclicos com 1 Anel/efeitos da radiação , Humanos , Luz , Fotoquimioterapia , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/efeitos da radiação , Oxigênio Singlete/metabolismoRESUMO
Two zinc(II) phthalocyanines (ZnPcs) substituted with a short peptide (Gly-Gly-Lys) with either a carboxyl or a carbamoyl group at the C-terminus and an appended biotin moiety were prepared and characterized. They could self-assemble into spherical nanoparticles, namely ZnPc-GGK(B)-COOH NP and ZnPc-GGK(B)-CONH2 NP, through noncovalent interactions, which encapsulated the hydrophobic ZnPc units in the core and exposed the biotin moieties on the surface. The zeta potential of ZnPc-GGK(B)-COOH NP in water was found to be -28 mV, whereas that of ZnPc-GGK(B)-CONH2 NP was in opposite sign (+15 mV), reflecting the different functionality at the C-terminus, which also greatly affected the stability of the self-assembled nanoparticles. The targeting effect of ZnPc-GGK(B)-COOH NP was examined against human hepatocellular carcinoma HepG2 cells, which overexpress biotin receptor, and Chinese Hamster Ovary CHO-K1 cells, which have a low expression of biotin receptor. This nanosystem was also coassembled with the chemotherapeutic doxorubicin (DOX) to form ZnPc-GGK(B)-COOH/DOX NP. Both ZnPc-GGK(B)-COOH NP and ZnPc-GGK(B)-COOH/DOX NP could induce photocytotoxicity and apoptosis on HepG2 cells with an IC50 value of 1.48 and 0.49 µM ZnPc, respectively. For the latter nanosystem, the ZnPc and DOX components induced cytotoxicity in a synergistic manner. The photodynamic and chemotherapeutic effects of these two nanosystems were also examined on nude mice bearing a human colorectal adenocarcinoma HT29 tumor. The ZnPc-GGK(B)-COOH/DOX NP exhibited a stronger tumor inhibition effect upon irradiation, demonstrating the presence of dual chemo-photodynamic therapeutic actions.
RESUMO
A distyryl boron dipyrromethene based photosensitiser substituted with 1,2,4,5-tetrazine and alkyne moieties was prepared. Through site-specific bioorthogonal reactions with the complementary functional tags anchored on the membrane of A431 human epidermoid carcinoma cells, this versatile photosensitiser exhibited enhanced cellular uptake and photocytotoxicity. The bioorthogonal ligation was also demonstrated in tumour-bearing nude mice.
Assuntos
Antineoplásicos/farmacologia , Compostos de Boro/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Porfobilinogênio/análogos & derivados , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Compostos de Boro/síntese química , Compostos de Boro/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Imagem Óptica , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Porfobilinogênio/síntese química , Porfobilinogênio/química , Porfobilinogênio/farmacologia , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-AtividadeRESUMO
A ferrocenyl boron dipyrromethene (BODIPY) has been developed and utilized as a dark quencher to construct a cathepsin B-responsive fluorescent probe and photosensitizer. The smart fluorescent probe and photosensitizer (Pc-FcQ) contains a zinc(II) phthalocyanine as the fluorescent and photosensitizing unit which is conjugated to the ferrocenyl BODIPY dark quencher via a cathepsin B-cleavable peptide substrate [Gly-Phe-Leu-Gly-Lys]. The photosensitizing properties of Pc-FcQ, including fluorescence and singlet oxygen generation, are significantly quenched through energy transfer to the BODIPY unit and subsequently by the photoinduced electron transfer from the nearby ferrocenyl moiety. Upon exposure of cathepsin B in human hepatocellular carcinoma HepG cells, the fluorescence emission of Pc-FcQ could be restored, indicating the cleavage of the peptide substrate and the separation of the phthalocyanine and ferrocenyl BODIPY unit. However, the intracellular fluorescence intensity of Pc-FcQ was largely diminished after the cells were pre-treated with cathepsin B inhibitor. Its intracellular fluorescence intensity was comparable to that of the control compound in which the peptide substrate was replaced by the non-cleavable one [Gly-Gly-Gly-Gly-Lys]. The singlet oxygen generation of Pc-FcQ was also examined in HepG2 cells as reflected by the cytotoxicity assay. The Pc-FcQ exhibited higher potency when compared with the non-cleavable analogue due to the cleavage of peptide substrate and the detachment of the BODIPY dark quencher from the phthalocyanine. The activation of the Pc-FcQ was also demonstrated in tumor-bearing nude mice. After intratumoral injection of Pc-FcQ, the fluorescence intensity at the tumor region increased gradually over 10â¯h as a result of the detachment of the dark quencher upon the action of cathepsin B. All the results suggest that this ferrocenyl BODIPY could serve as an efficient dark quencher and the resulting Pc-FcQ could act as the cathepsin B-responsive fluorescent probe and activatable photosensitizer.
Assuntos
Boro/farmacologia , Catepsina B/farmacologia , Compostos Ferrosos/farmacologia , Corantes Fluorescentes/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Porfobilinogênio/análogos & derivados , Animais , Boro/química , Catepsina B/química , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Compostos Ferrosos/química , Corantes Fluorescentes/química , Células HT29 , Células Hep G2 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Imagem Óptica , Fármacos Fotossensibilizantes/química , Porfobilinogênio/química , Porfobilinogênio/farmacologia , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
A zinc(II) phthalocyanine substituted with three 2,4-dinitrobenzenesulfonate (DNBS) groups and a cyclic arginine-glycine-aspartic acid (cRGDfK) moiety was prepared and characterized. With three strongly electron-withdrawing DNBS groups, this compound was fully quenched in terms of fluorescence emission and singlet oxygen generation in N,N-dimethylformamide and phosphate buffered saline due to the strong photoinduced electron transfer effect. In the presence of glutathione (GSH), which is the most abundant intracellular thiol particularly in tumor cells, the DNBS moieties were cleaved, thereby restoring these photoactivities and making the conjugate as a GSH-activated photosensitizer. Being a well-known integrin antagonist, the cyclic RGD peptide sequence could enhance the localization of the conjugate in integrin-upregulated tumor cells. As shown by confocal laser scanning microscopy and flow cytometry, the intracellular fluorescence intensity of the conjugate was significantly higher in the integrin-positive A549 and MDA-MB-231â¯cells than in the integrin-negative MCF-7 and HEK293â¯cells. The photocytotoxicity of the conjugate against MDA-MB-231â¯cells was also higher than that toward MCF-7â¯cells. The results suggest that this dual-functional photosensitizer is a promising candidate for targeted photodynamic therapy.
Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Glutationa/metabolismo , Indóis/farmacologia , Peptídeos Cíclicos/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Antineoplásicos/efeitos da radiação , Benzenossulfonatos/síntese química , Benzenossulfonatos/metabolismo , Benzenossulfonatos/farmacologia , Benzenossulfonatos/efeitos da radiação , Linhagem Celular Tumoral , Complexos de Coordenação/síntese química , Complexos de Coordenação/metabolismo , Complexos de Coordenação/efeitos da radiação , Fluorescência , Células HEK293 , Humanos , Indóis/síntese química , Indóis/metabolismo , Indóis/efeitos da radiação , Integrinas/metabolismo , Luz , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/metabolismo , Peptídeos Cíclicos/efeitos da radiação , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/metabolismo , Fármacos Fotossensibilizantes/efeitos da radiação , Oxigênio Singlete/metabolismo , Zinco/químicaRESUMO
A peptide-conjugated zinc(ii) phthalocyanine containing the epidermal growth factor receptor-targeted heptapeptide QRHKPRE has been prepared. The conjugate labelled as ZnPc-QRH* can selectively bind to the cell membrane of HT29 human colorectal adenocarcinoma cells in 10 min followed by internalisation upon prolonged incubation via receptor-mediated endocytosis, leading to localisation in lysosomes eventually. By manipulating the incubation time, the subcellular localisation of the conjugate can be varied and the cell-death pathways induced upon irradiation can also be altered. It has been found that photosensitisation initiated at the cell membrane and in the lysosomes would trigger cell death mainly through necrosis and apoptosis respectively. Intravenous administration of the conjugate into HT29 tumour-bearing nude mice resulted in higher accumulation in the tumour than in most major organs. The selective binding of this conjugate to tumour has also been demonstrated by comparing the results with those of the analogue with a scrambled peptide sequence (EPRQRHK). The overall results indicate that ZnPc-QRH* is a promising EGFR-targeted photosensitiser for photodynamic therapy.
RESUMO
A series of disulfide-linked dendritic phthalocyanines were synthesized by using the CuI -catalyzed alkyne-azide cycloaddition reaction as the key step. Whereas these compounds were essentially nonaggregated in N,N-dimethylformamide, they were stacked in citrate solution (pHâ 7.4, with 1 % Cremophorâ EL), as shown by the broad appearance of their Q-band absorption. Having two-to-six zinc(II) phthalocyanine units in a molecule, these compounds were significantly self-quenched, particularly in citrate solution. Both the fluorescence intensity and singlet-oxygen generation efficiency were significantly lower than those of the monomeric counterparts, and the self-quenching efficiency increased as the number of phthalocyanine units increased. Upon interaction with 5â mm glutathione (GSH) in citrate solution, the fluorescence intensity of these compounds increased as a result of cleavage of the disulfide linkages and separation of the phthalocyanine units, which thereby reduced the self-quenching effect. The "on/off" ratios were found to be 7, 18, 23, and 21 for the dimeric (PC2), trimeric (PC3), tetrameric (PC4), and hexameric (PC6) systems, respectively. GSH also enhanced the fluorescence emission inside human colon adenocarcinoma HT29 cells and promoted the formation of singlet oxygen of these compounds. Upon irradiation, their half maximal inhibitory concentration (IC50 ) values were found to be in the range of 0.18 to 0.38â µm. Finally, the biodistribution and activation of PC2 and PC6 were also examined in HT29 tumor-bearing nude mice. For both compounds, the fluorescence intensity per unit area at the tumor was found to grow gradually during the first 24â h. Whereas the intensity then dropped for PC2, the intensity for PC6 remained steady over the following 6â d, which might have been a result of the enhanced permeability and retention effect arising from the larger molecular mass of the hexameric system.
Assuntos
Dissulfetos/química , Glutationa/química , Indóis/síntese química , Fármacos Fotossensibilizantes/síntese química , Animais , Reação de Cicloadição , Dimetilformamida/química , Fluorescência , Glutationa/metabolismo , Células HT29 , Humanos , Concentração de Íons de Hidrogênio , Indóis/química , Isoindóis , Camundongos Nus , Compostos Organometálicos/química , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/uso terapêutico , Oxigênio Singlete/química , Relação Estrutura-Atividade , Distribuição Tecidual , ZincoRESUMO
Doxorubicin (Dox) was conjugated to a zinc(II) phthalocyanine (ZnPc) through an acid-cleavable hydrazone linker. This azido-containing conjugate was then anchored to the nanochannels of an alkyne-modified mesoporous silica nanoparticle (MSN) system via copper(I)-catalyzed azide-alkyne cycloaddition. An analogous nanosystem was also prepared by immobilization of a hydrazine-substituted ZnPc to the MSN followed by coupling with Dox. The release of Dox under acidic conditions was studied in phosphate-buffered saline. After internalization into human hepatocellular carcinoma HepG2 cells, these nanoparticles showed fluorescence not only for ZnPc, but also for Dox, suggesting that release of Dox was triggered by the acidic intracellular environment. The chemocytotoxic Dox together with singlet oxygen generated upon irradiation on the encapsulated ZnPc in these MSNs could kill the cells effectively. A synergistic cytotoxicity was suggested by a less-than-unity combination index. These nanoparticles function as both nanophotosensitizers for photodynamic therapy and as nanoplatforms for pH-controlled drug release.
Assuntos
Doxorrubicina/química , Portadores de Fármacos/química , Indóis/química , Nanopartículas/química , Compostos Organometálicos/química , Dióxido de Silício/química , Alcinos/química , Reação de Cicloadição , Doxorrubicina/metabolismo , Liberação Controlada de Fármacos , Difusão Dinâmica da Luz , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Isoindóis , Luz , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Fotoquimioterapia , Porosidade , Oxigênio Singlete/metabolismo , Compostos de ZincoRESUMO
An acid-cleavable acetal-linked zinc(II) phthalocyanine dimer with an azido terminal group (cPc) was prepared and conjugated to alkyne-modified mesoporous silica nanoparticles via copper(I)-catalyzed alkyne-azide cycloaddition reaction. For comparison, an amine-linked analogue (nPc) was also prepared as a non-acid-cleavable counterpart. These dimeric phthalocyanines were significantly self-quenched due to the close proximity of the phthalocyanine units inside the mesopores, resulting in much weaker fluorescence emission and singlet oxygen generation, both in N,N-dimethylformamide and in phosphate-buffered saline (PBS), compared with the free molecular counterparts. Under acidic conditions in PBS, the cPc-encapsulated nanosystem was activated in terms of fluorescence emission and singlet oxygen production. After internalization into human colon adenocarcinoma HT29 cells, it exhibited much higher intracellular fluorescence and photocytotoxicity compared to the nanosystem entrapped with nPc. The activation of this nanosystem was also demonstrated in tumor-bearing nude mice. The intratumoral fluorescence intensity increased gradually over 24 h, while for the nPc counterpart the fluorescence remained very weak. The results suggest that this nanosystem serves as a promising activatable nanophotosensitizing agent for photodynamic therapy.