RESUMO
This study demonstrates the potential of sono-photodynamic therapy as an effective approach for enhancing singlet oxygen generation using the synthesized Schiff-base diaxially substituted silicon phthalocyanines. In photochemical studies, the singlet oxygen quantum yields (Φ∆) were determined as 0.43 for Si1a, 0.94 for Q-Si1a, 0.58 for S-Si1a, and 0.49 for B-Sia1. In sono-photochemical studies, the Φ∆ values were reached to 0.67 for Si1a, 1.06 for Q-Si1a, 0.65 for S-Si1a, and 0.67 for B-Sia1. In addition, this study demonstrates the therapeutic efficacy of phthalocyanines synthesized as sensitizers on the PC3 prostate cancer cell line through in vitro experiments. The application of these treatment modalities exhibited notable outcomes, leading to a substantial decrease in cell viability within the PC3 prostate cancer cell line. These findings highlight the potential of utilizing these synthesized phthalocyanines as promising therapeutic agents for prostate cancer treatment.
Assuntos
Sobrevivência Celular , Indóis , Compostos de Organossilício , Neoplasias da Próstata , Bases de Schiff , Oxigênio Singlete , Humanos , Indóis/química , Indóis/farmacologia , Bases de Schiff/química , Bases de Schiff/farmacologia , Masculino , Oxigênio Singlete/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Neoplasias da Próstata/metabolismo , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Ensaios de Seleção de Medicamentos Antitumorais , Células PC-3 , Fotoquimioterapia , Processos Fotoquímicos , Linhagem Celular Tumoral , Estrutura MolecularRESUMO
An intelligent delivery nanoformulation could enhance the utilization efficacy, uptake, and translocation of pesticides in plants. Herein, a redox/pH-triggered and fluorescent smart delivery nanoformulation was designed and constructed by using hollow mesoporous organosilica nanoparticles (HMONs) and ZnO quantum dots as the nanocarrier and capping agent, respectively. Boscalid was further loaded to generate Boscalid@HMONs@ZnO with a loading rate of 9.8% for controlling Botrytis cinerea (B. cinerea). The quantity of boscalid released by Boscalid@HMONs@ZnO in a glutathione environment or at pH 3.0 was 1.3-fold and 1.9-fold higher than that in a neutral condition. Boscalid@HMONs@ZnO has 1.7-fold the toxicity index of boscalid technical against B. cinerea in antifungal experiments. Pot experiments revealed that the efficacy of Boscalid@HMONs@ZnO was significantly enhanced more than 1.27-fold compared to commercially available water-dispersible granules of boscalid. Due to the fluorescence properties of Boscalid@HMONs@ZnO, pesticide transport's real-time monitoring of pesticide translocation in tomato plants could be observed by confocal laser scanning microscopy. Fluorescence images revealed that HMONs@ZnO had been effectively transported via treated leaves or roots in tomato plants. This research showed the successful application of HMONs@ZnO as a nanocarrier for controlling disease and offered an effective avenue to explore the real-time tracking of pesticide translocation in plants.
Assuntos
Botrytis , Nanopartículas , Oxirredução , Óxido de Zinco , Botrytis/efeitos dos fármacos , Nanopartículas/química , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Concentração de Íons de Hidrogênio , Corantes Fluorescentes/química , Compostos de Bifenilo/química , Pontos Quânticos/química , Pontos Quânticos/toxicidade , Solanum lycopersicum/química , Praguicidas/química , Praguicidas/toxicidade , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Liberação Controlada de Fármacos , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Niacinamida/análogos & derivadosRESUMO
Myopia is a global public health issue. Rigid contact lenses (RCLs) are an effective way to correct or control myopia. However, bioadhesion issues remain one of the significant obstacles limiting its clinical application. Although enhancing hydrophilicity through various surface treatments can mitigate this problem, the duration of effectiveness is short-lived and the processing involved is complex and costly. Herein, an antiadhesive RCLs material was designed via 8-armed methacrylate-POSS (8MA-POSS), and poly(ethylene glycol) methacrylate (PEGMA) copolymerization with 3-[tris(trimethylsiloxy)silyl] propyl methacrylate (TRIS). The POSS and PEG segments incorporated P(TRIS-co-PEGMA-co-8MA-POSS) (PTPM) material was obtained and their optical transparency, refractive index, resolution, hardness, surface charge, thermal features, and wettability were tested and optimized. The antibioadhesion activities, including protein, lipid, and bacteria, were evaluated as well. In vitro and in vivo results indicated that the optimized antibioadhesive PTPM materials present good biocompatibility and biosafety. Thus, such POSS and PEG segments containing material were a potential antibioadhesive RCL material option.
Assuntos
Lentes de Contato , Metacrilatos , Compostos de Organossilício , Polietilenoglicóis , Polietilenoglicóis/química , Metacrilatos/química , Animais , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Camundongos , Materiais Biocompatíveis/química , Humanos , Miopia/tratamento farmacológicoRESUMO
To investigate the renal protective effects of the polysaccharide LEP-1a and derivatives of selenium (SeLEP-1a) from Lachnum YM38, cisplatin (CP) was used to establish an acute kidney model. LEP-1a and SeLEP-1a could effectively reverse the decrease in renal index and improved renal oxidative stress. LEP-1a and SeLEP-1a significantly reduced the contents of the inflammatory cytokines. They could inhibit the release of cyclooxygenase 2 (COX-2) and nitric oxide synthase (iNOS) and increase the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1). At the same time, the PCR results indicated that SeLEP-1a could significantly inhibit the mRNA expression levels of toll-like receptor 4 (TLR4), nuclear factor-kB (NF-κB) p65 and inhibitor of kappa B-alpha (IκBα). Western blot analysis showed that LEP-1a and SeLEP-1a significantly downregulated the expression levels of Bcl-2-associated X protein (Bax) and cleaved caspase-3 and upregulated phosphatidylinositol 3-kinase (p-PI3K), protein kinase B (p-Akt) and B-cell lymphoma 2 (Bcl-2) protein expression levels in the kidney. LEP-1a and SeLEP-1a could improve CP-induced acute kidney injury by regulating the oxidative stress response, NF-κB-mediated inflammation and the PI3K/Akt-mediated apoptosis signalling pathway.
Assuntos
Injúria Renal Aguda , Polissacarídeos , Selênio , Animais , Camundongos , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/prevenção & controle , Cisplatino/farmacologia , Cisplatino/toxicidade , Rim/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Compostos de Organossilício/metabolismo , Compostos de Organossilício/farmacologia , Estresse Oxidativo , Fosfatidilinositol 3-Quinases/metabolismo , Polissacarídeos/farmacologia , Polissacarídeos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Selênio/farmacologiaRESUMO
BACKGROUND: Chemotherapy, the mainstay treatment for metastatic cancer, presents serious side effects due to off-target exposure. In addition to the negative impact on patients' quality of life, side effects limit the dose that can be administered and thus the efficacy of the drug. Encapsulation of chemotherapeutic drugs in nanocarriers is a promising strategy to mitigate these issues. However, avoiding premature drug release from the nanocarriers and selectively targeting the tumour remains a challenge. RESULTS: In this study, we present a pioneering method for drug integration into nanoparticles known as mesoporous organosilica drugs (MODs), a distinctive variant of periodic mesoporous organosilica nanoparticles (PMOs) in which the drug is an inherent component of the silica nanoparticle structure. This groundbreaking approach involves the chemical modification of drugs to produce bis-organosilane prodrugs, which act as silica precursors for MOD synthesis. Mitoxantrone (MTO), a drug used to treat metastatic breast cancer, was selected for the development of MTO@MOD nanomedicines, which demonstrated a significant reduction in breast cancer cell viability. Several MODs with different amounts of MTO were synthesised and found to be efficient nanoplatforms for the sustained delivery of MTO after biodegradation. In addition, Fe3O4 NPs were incorporated into the MODs to generate magnetic MODs to actively target the tumour and further enhance drug efficacy. Importantly, magnetic MTO@MODs underwent a Fenton reaction, which increased cancer cell death twofold compared to non-magnetic MODs. CONCLUSIONS: A new PMO-based material, MOD nanomedicines, was synthesised using the chemotherapeutic drug MTO as a silica precursor. MTO@MOD nanomedicines demonstrated their efficacy in significantly reducing the viability of breast cancer cells. In addition, we incorporated Fe3O4 into MODs to generate magnetic MODs for active tumour targeting and enhanced drug efficacy by ROS generation. These findings pave the way for the designing of silica-based multitherapeutic nanomedicines for cancer treatment with improved drug delivery, reduced side effects and enhanced efficacy.
Assuntos
Antineoplásicos , Neoplasias da Mama , Sobrevivência Celular , Mitoxantrona , Compostos de Organossilício , Humanos , Neoplasias da Mama/tratamento farmacológico , Feminino , Sobrevivência Celular/efeitos dos fármacos , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Mitoxantrona/farmacologia , Mitoxantrona/química , Mitoxantrona/uso terapêutico , Linhagem Celular Tumoral , Portadores de Fármacos/química , Dióxido de Silício/química , Porosidade , Liberação Controlada de Fármacos , Nanopartículas/química , Células MCF-7 , Nanomedicina/métodos , Espécies Reativas de Oxigênio/metabolismoRESUMO
In this study, three new axially disubstituted silicon phthalocyanines (SiPc1-3) and their quaternized phthalocyanine derivatives (QSiPc1-3) were prepared and characterized. The biological properties (antioxidant, antimicrobial, antibiofilm, and microbial cell viability activities) of the water-soluble silicon phthalocyanines were examined, as well. A 1 % DMSO diluted with pure water was used as a solvent in biological activity studies. All the compounds exhibited high antioxidant activity. They displayed efficient antimicrobial and antimicrobial photodynamic therapeutic properties against various microorganisms, especially Gram (+) bacteria. Additionally, they demonstrated high antibiofilm activities against S. aureus and P. aeruginosa. In addition, 100 % bacterial reduction was obtained for all the studied phthalocyanines against E. coli viable cells. Besides, the DNA cleavage and binding features of compounds (QSiPc1-3) were studied using pBR322 DNA and CT-DNA, respectively. Furthermore, the human topoisomerase I enzyme inhibition activities of compounds QSiPc1-3 were studied. Anticancer properties of the water-soluble compounds were investigated using cell proliferation MTT assay. They exhibited anticarcinogenic activity against the human colon cancer cell line (DLD-1). Compounds QSiPc1 and QSiPc3 displayed a high anticarcinogenic effect on the DLD-1â cell line. The obtained results indicated that all the studied compounds may be effective biological agents and anticancer drugs after further investigations.
Assuntos
Anti-Infecciosos , Antineoplásicos , Compostos de Organossilício , Staphylococcus aureus , Humanos , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , DNA/química , Escherichia coli/efeitos dos fármacos , Ligantes , Staphylococcus aureus/efeitos dos fármacos , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Ácidos Ftálicos/química , Ácidos Ftálicos/farmacologiaRESUMO
Near-infrared photoimmunotherapy (NIR-PIT) is a cell selective cancer therapy that uses an antibody-photoabsorber (IRDye700DX, IR700) conjugate (APC) and NIR light. NIR-PIT targeting epidermal growth factor receptor (EGFR) in head and neck cancer (HNC) was conditionally approved in Japan in 2020. APC-bound tumors can be detected using endoscopic fluorescence imaging, whereas NIR light can be delivered using endoscopic fiber optics. The aims of this study were: (1) to assess the feasibility of endoscopic NIR-PIT in an orthotopic HNC model using a CD44-expressing MOC2-luc cell line; and (2) to evaluate quantitative fluorescence endoscopic imaging prior to and during NIR-PIT. The results were compared in 3 experimental groups: (1) untreated controls, (2) APC injection without light exposure (APC-IV), and (3) APC injection followed by NIR light exposure (NIR-PIT). APC injected groups showed significantly higher fluorescence signals for IR700 compared with the control group prior to therapeutic NIR light exposure, and the fluorescence signal significantly decreased in the NIR-PIT group after light exposure. After treatment, the NIR-PIT group showed significantly attenuated bioluminescence compared with the control and the APC-IV groups. Histology demonstrated diffuse necrotic death of the cancer cells in the NIR-PIT group alone. In conclusion, endoscopically delivered light combined with quantitative fluorescence imaging can be used to "see and treat" HNC. This method could also be applied to other types of cancer approachable with endoscopy.
Assuntos
Antineoplásicos Imunológicos/administração & dosagem , Neoplasias de Cabeça e Pescoço/terapia , Receptores de Hialuronatos/antagonistas & inibidores , Indóis/administração & dosagem , Compostos de Organossilício/administração & dosagem , Administração Intravenosa , Animais , Antineoplásicos Imunológicos/química , Antineoplásicos Imunológicos/farmacologia , Linhagem Celular Tumoral , Endoscopia , Estudos de Viabilidade , Feminino , Neoplasias de Cabeça e Pescoço/imunologia , Imunoterapia , Indóis/química , Indóis/farmacologia , Camundongos , Imagem Óptica , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Fototerapia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Human induced pluripotent stem cells (hiPSCs) are important starting materials for cell therapy products (CTPs) used for transplantation. During cell culture, hiPSCs often spontaneously undergo morphological changes and lose pluripotency. Such cells are called 'deviated cells', which are deviated from the undifferentiated state of hiPSCs, lack the expression of hiPSC markers and become positive for the early differentiation marker SSEA1 (stage-specific embryonic antigen 1, Lewis X glycan). Previously, we identified fibronectin (FN) as a predominant carrier protein of SSEA1 secreted from deviated cells, but not hiPSCs. A sandwich assay using antibodies (Abs) against FN and SSEA1 was developed for non-destructive quantitative evaluation of deviated cells present in hiPSC cultures. In this study, a novel technology was developed to specifically eliminate deviated cells using an anti-FN Ab along with a near-infrared (NIR) photoabsorber, IRDye700DX N-hydroxysuccinimide ester (IR700), which has been used for cancer photoimmunotherapy. The anti-FN Ab conjugated with the IR700 dye (IR700-αFN) bound to and induced the death of deviated cells upon NIR irradiation. In contrast, IR700-αFN failed to stain the hiPSCs, and IR700-αFN/NIR had little or no effect on survival. Finally, IR700-αFN/NIR irradiation induced selective removal of deviated cells from a mixed culture with hiPSCs, demonstrating that the proposed method is suitable for the removal of unwanted deviated cells present in hiPSC culture for the production of CTPs.
Assuntos
Separação Celular/métodos , Fibronectinas/metabolismo , Imunoconjugados/farmacologia , Indóis/química , Células-Tronco Pluripotentes Induzidas/citologia , Compostos de Organossilício/química , Técnicas de Cultura de Células , Proliferação de Células , Fibronectinas/imunologia , Humanos , Imunoconjugados/efeitos da radiação , Fatores Imunológicos/farmacologia , Indóis/farmacologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Raios Infravermelhos , Compostos de Organossilício/farmacologiaRESUMO
Photodynamic therapy (PDT) is an anti-tumor modality which employs three individually non-toxic substances, including photosensitizer, light and oxygen, to produce a toxic effect. Besides causing damage to blood vessels that supply oxygen and nutrients to the tumor and killing the tumor by a direct cytotoxic effect, PDT has also been known to trigger an anti-tumor immune response. For instance, our previous study showed that PDT with BAM-SiPc, a silicon(IV) phthalocyanine based-photosensitizer, can not only eradicate the mouse CT26 tumor cells in a Balb/c mouse model, but also protect the mice against further re-challenge of the tumor cells through an immunomodulatory mechanism. To understand more about the immune effect, the biochemical actions of BAM-SiPc-PDT on CT26 cells were studied in the in vitro system. It was confirmed that the PDT treatment could induce immunogenic necroptosis in the tumor cells. Upon treatment, different damage-associated molecular patterns were exposed onto the cell surface or released from the cells. Among them, calreticulin was found to translocate to the cell membrane through a pathway similar to that in chemotherapy. The activation of immune response was also demonstrated by an increase in the expression of different chemokines.
Assuntos
Indóis/uso terapêutico , Necroptose/imunologia , Compostos de Organossilício/uso terapêutico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Animais , Linhagem Celular Tumoral , Humanos , Indóis/farmacologia , Isoindóis , Camundongos , Compostos de Organossilício/farmacologia , Fármacos Fotossensibilizantes/farmacologiaRESUMO
BACKGROUND/AIMS: IR700DX-6T and IR700DX-mbc94 are two chemically synthesized photosensitizers (PSs) that target the translocator protein (TSPO) and type 2 cannabinoid receptor (CB2R), respectively, for photodynamic therapy (PDT) of cancer. Recently, we found that IR700DX-6T and IR700DX-mbc94 exhibited high selectivity and efficiency in PDT for breast cancer and malignant astrocytoma. Yet, the phototherapeutic effects of the PSs on pancreatic cancer and underlying mechanisms remain unknown. This study investigated the effect of IR700DX-6T- or IR700DX-mbc94-PDT on pancreatic cancer and whether the treatment involves eliciting anticancer immune responses in support of superior therapeutic efficacy. METHODS: Four pancreatic cancer cell lines were used for in vitro studies. C57BL/6 mice bearing pancreatic cancer cell-derived xenografts were generated for in vivo studies regarding the therapeutic effects of IR700DX-6T-PDT and IR700DX-mbc94-PDT on pancreatic cancer. The immunostimulatory or immunosuppressive effects of IR700DX-6T-PDT and IR700DX-mbc94-PDT were examined by detecting CD8+ T cells, regulatory T cells (Tregs), and dendritic cells (DCs) using flow cytometry and immunohistochemistry (IHC). RESULTS: TSPO and CB2R were markedly upregulated in pancreatic cancer cells and tissues. Both IR700DX-6T-PDT and IR700DX-mbc94-PDT significantly inhibited pancreatic cancer cell growth in a dose- and time-dependent manner. Notably, assessment of anticancer immune responses revealed that both IR700DX-6T-PDT and IR700DX-mbc94-PDT significantly induced CD8+ T cells, promoted maturation of DCs, and suppressed Tregs, with stronger effects exerted by IR700DX-6T-PDT compared to IR700DX-mbc94-PDT. CONCLUSIONS: IR700DX-6T-PDT and IR700DX-mbc94-PDT involves eliciting anticancer immune responses. Our study has also implicated that PDT in combination with immunotherapy holds promise to improve therapeutic efficacy for patients with pancreatic cancer.
Assuntos
Indóis/uso terapêutico , Compostos de Organossilício/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Trifosfato de Adenosina/metabolismo , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Humanos , Indóis/farmacologia , Linfonodos/citologia , Linfonodos/imunologia , Camundongos Endogâmicos C57BL , Compostos de Organossilício/farmacologia , Pâncreas/metabolismo , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Receptor CB2 de Canabinoide/metabolismo , Receptores de GABA/metabolismo , Baço/citologia , Baço/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologiaRESUMO
Cancer has become an important public problem in worldwide since cancer incidence and mortality are growing rapidly. In this study, water soluble and non-aggregated silicon (IV) phthalocyanines and naphthalocyanines containing (3,5-bis{3-[3-(diethylamino)phenoxy]propoxy}phenyl)methoxy groups have been synthesized and characterized to investigate their anticancer potential. Their DNA binding/nuclease, topoisomerases inhibition were investigated using UV-Vis absorption, thermal denaturation and agarose gel electrophoresis. The in vitro cytotoxic properties of the compounds on human lung (A549), breast (BT-20), liver (SNU-398), prostate (DU-145), melanoma (SK-Mel 128) carcinoma and human fibroblast (HFC) normal cell lines were evaluated by using MTT assay. In order to determine the mechanism of cancer cell growth suppression, cell cycle analysis was carried out using flow cytometer on A549 cell line. The Kb values of SiPc1a and SiNc2a were 6.85 ± (0.35) × 106 and 1.72 ± (0.16) × 104 M-1 and Tm values of ct-DNA were calculated as 82.02 °C and 78.07 °C, respectively in the presence of both compounds. The ΔTm values of SiPc1a and SiNc2a were calculated as 6.45 and 2.50 °C, respectively. The nuclease effects of SiPc1a and SiNc2a with supercoiled plasmid pBR322 DNA demonstrated that both compounds did not trigger any DNA nuclease effects at the lowest concentrations without irradiation whereas both compounds in the presence of activating agent (H2O2) showed significant plasmid DNA nuclease actions under irradiation (22.5 J/cm2). SiPc1a and SiNc2a inhibited to topoisomerase I on increasing concentrations whilst they had lower inhibition action toward topoisomerase II that of topoisomerase I. The in vitro cytotoxicity studies displayed that SiPc1a had the highest cytotoxic effects among the tested compounds against A549, SNU-398, SK-MEL128, DU-145, BT-20 and HFC cell lines with CC50 values ranged from 0.49 to 2.99 µM. Furthermore, SiPc1a inhibited cell proliferation by cell cycle arrest in G0/G1 phase. All of these results suggested that SiPc1a is a promising candidate as an anticancer agent.
Assuntos
Antineoplásicos/síntese química , Desenho de Fármacos , Indóis/química , Compostos de Organossilício/química , Inibidores da Topoisomerase I/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA/química , DNA/metabolismo , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/metabolismo , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , Desoxirribonucleases/antagonistas & inibidores , Desoxirribonucleases/metabolismo , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/farmacologia , Indóis/metabolismo , Indóis/farmacologia , Compostos de Organossilício/metabolismo , Compostos de Organossilício/farmacologia , Solubilidade , Inibidores da Topoisomerase I/metabolismo , Inibidores da Topoisomerase I/farmacologia , Água/químicaRESUMO
The Threshold of Toxicological Concern (TTC) for non-genotoxic substances, a risk assessment tool to establish safe exposure levels for chemicals with insufficient toxicological data, is based on the 5th percentile of cumulated distributions of Point of Departures in a high amount of repeat-dose, developmental and reproductive toxicity studies, grouped by Cramer Classes. The lack of organosilicon compounds in this dataset has resulted in regulatory concerns over the applicability of the TTC concept for this chemistry. We collected publicly available, scientifically robust oral repeat-dose and DART studies for 71 organosilicon substances for inclusion in the existing TTC dataset, using criteria for evaluation of studies and derivation of points of departure analogous to the Munro and COSMOS TTC publications. The resulting 5th percentile of this dataset was 13-fold higher than the 5th percentile for Cramer Class III compounds reported by Munro (which is the default for silicon-containing substances). Both the existing TTC for Cramer Class III compounds from Munro (1.5 µg/kg bw/day) and the COSMOS TTC (2.3 µg/kg bw/day), recommended by the SCCS for cosmetics-related substances, provide a conservative and sufficiently protective approach for this class of chemistry.
Assuntos
Compostos de Organossilício/farmacologia , Reprodução/efeitos dos fármacos , Animais , Testes de Carcinogenicidade , Cosméticos/farmacologia , Cosméticos/toxicidade , Bases de Dados Factuais , Relação Dose-Resposta a Droga , Testes de Mutagenicidade , Nível de Efeito Adverso não Observado , Compostos de Organossilício/toxicidade , Praguicidas/farmacologia , Praguicidas/toxicidade , Coelhos , RoedoresRESUMO
Human immunodeficiency virus (HIV-1) is still a major problem, not only in developing countries but is also re-emerging in several developed countries, thus the development of new compounds able to inhibit the virus, either for prophylaxis or treatment, is still needed. Nanotechnology has provided the science community with several new tools for biomedical applications. G2-S16 is a polyanionic carbosilane dendrimer capable of inhibiting HIV-1 in vitro and in vivo by interacting directly with viral particles. One of the main barriers for HIV-1 eradication is the reservoirs created in primoinfection. These reservoirs, mainly in T cells, are untargetable by actual drugs or immune system. Thus, one approach is inhibiting HIV-1 from reaching these reservoir cells. In this context, macrophages play a main role as they can deliver viral particles to T cells establishing reservoirs. We showed that G2-S16 dendrimer is capable of inhibiting the infection from infected macrophages to healthy T CD4/CD8 lymphocytes by eliminating HIV-1 infectivity inside macrophages, so they are not able to carry infectious particles to other body locations, thus preventing the reservoirs from forming.
Assuntos
Alcanossulfonatos/farmacologia , Fármacos Anti-HIV/farmacologia , Dendrímeros/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Compostos de Organossilício/farmacologia , Silanos/farmacologia , Linhagem Celular , Células Cultivadas , Infecções por HIV/transmissão , Humanos , Macrófagos/virologia , Polieletrólitos/farmacologiaRESUMO
The selective inhibition of immunoproteasome is a valuable strategy to treat autoimmune, inflammatory diseases, and hematologic malignancies. Recently, a new series of amide derivatives as non-covalent inhibitors of the ß1i subunit with Ki values in the low/submicromolar ranges have been identified. Here, we investigated the binding mechanism of the most potent and selective inhibitor, N-benzyl-2-(2-oxopyridin-1(2H)-yl)propanamide (1), to elucidate the steps from the ligand entrance into the binding pocket to the ligand-induced conformational changes. We carried out a total of 400 ns of MD-binding analyses, followed by 200 ns of plain MD. The trajectories clustering allowed identifying three representative poses evidencing new key interactions with Phe31 and Lys33 together in a flipped orientation of a representative pose. Further, Binding Pose MetaDynamics (BPMD) studies were performed to evaluate the binding stability, comparing 1 with four other inhibitors of the ß1i subunit: N-benzyl-2-(2-oxopyridin-1(2H)-yl)acetamide (2), N-cyclohexyl-3-(2-oxopyridin-1(2H)-yl)propenamide (3), N-butyl-3-(2-oxopyridin-1(2H)-yl)propanamide (4), and (S)-2-(2-oxopyridin-1(2H)-yl)-N,4-diphenylbutanamide (5). The obtained results in terms of free binding energy were consistent with the experimental values of inhibition, confirming 1 as a lead compound of this series. The adopted methods provided a full dynamic description of the binding events, and the information obtained could be exploited for the rational design of new and more active inhibitors.
Assuntos
Simulação de Acoplamento Molecular , Complexo de Endopeptidases do Proteassoma/química , Inibidores de Proteassoma/farmacologia , Sítios de Ligação , Dipeptídeos/química , Dipeptídeos/farmacologia , Simulação de Dinâmica Molecular , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/química , Ligação ProteicaRESUMO
Prodrugs that allow inâ situ chemical conversion of less toxic precursors into active drugs in response to certain stimuli are promising anticancer candidates. Herein, we present a novel design of nanoprodrugs with a "degradation-mediated self-toxification" strategy, which realizes intracellular synthesis of anticancer agents using the nanoparticles' own degradation fragments as the precursors. To fulfill this concept, a metal complexing dicyclohexylphosphine (DCP) organosilane is carefully screened out from various ligands to conjugate onto Pd(OH)2 nanodots confined hollow silica nanospheres (PD-HSN). This constructed nanoprodrug shows acid-triggered degradation in lysosomes and neutralizes protons to induce lysosomes rupturing, generating predesigned less toxic fragments (Pd2+ and DCP-silicates) that complex into DCP/Pd complex inâ situ for inducing DNA damage, leading to enhanced anticancer activity against various cancer cell lines as well as in a xenograft tumour model.
Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Nanopartículas/química , Compostos de Organossilício/farmacologia , Pró-Fármacos/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração de Íons de Hidrogênio , Ligantes , Lisossomos/química , Camundongos , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Compostos de Organossilício/síntese química , Compostos de Organossilício/química , Pró-Fármacos/síntese química , Pró-Fármacos/químicaRESUMO
BACKGROUND: Hospital acquired infections (HAI) are the most common complication found in the hospital environment. The aim of the study was to examine whether the use of an antimicrobial coating in high-touch areas in an orthopedic ward could reduce bacterial growth and HAI. METHODS: From December 2017 to February 2018, HAI were registered on two orthopedic wards. A second registration was performed from December 2018 to February 2019. On the second occasion, an antimicrobial organosilane coating was applied just before the study period and thereafter weekly on one ward, while the other ward served as a control. Twenty defined high-touch areas on each ward were cultured before treatment and after 1, 2, 4, 8, 12, 14 and 16 weeks. Samples were cultured for aerobic colony counts, Staphylococcus aureus and E. coli. RESULTS: The total aerobic colony counts were 47% lower on the treated ward compared with the non-treated ward over the study period (p = 0.02). The colony counts for Staphylococcus aureus and E. coli were low on both wards. During the first registration period, the incidence of HAI was 22.7% and 20.0% on the non-treated and subsequently treated ward respectively. On the second occasion, after treatment, the incidence was 25.0% and 12.5% (treated ward) respectively (p = 0.0001). CONCLUSIONS: The use of a long-lasting antimicrobial organosilane coating appears to reduce the bioburden and reduce HAI. Since the incidence of HAI varies substantially over time, longer observation times are needed.
Assuntos
Infecção Hospitalar/microbiologia , Infecção Hospitalar/prevenção & controle , Escherichia coli/efeitos dos fármacos , Compostos de Organossilício/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Bactérias Aeróbias/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Infecções Bacterianas/prevenção & controle , Contagem de Colônia Microbiana , Humanos , Controle de Infecções/métodos , Quartos de Pacientes , Propriedades de SuperfícieRESUMO
BACKGROUND: CuS-modified hollow mesoporous organosilica nanoparticles (HMON@CuS) have been preferred as non-invasive treatment for cancer, as near infrared (NIR)-induced photo-thermal effect (PTT) and/or photo-dynamic effect (PDT) could increase cancer cells' apoptosis. However, the certain role of HMON@CuS-produced-PTT&PDT inducing gastric cancer (GC) cells' mitochondrial damage, remained unclear. Moreover, theranostic efficiency of HMON@CuS might be well improved by applying multi-modal imaging, which could offer an optimal therapeutic region and time window. Herein, new nanotheranostics agents were reported by Gd doped HMON decorated by CuS nanocrystals (called HMON@CuS/Gd). RESULTS: HMON@CuS/Gd exhibited appropriate size distribution, good biocompatibility, L-Glutathione (GSH) responsive degradable properties, high photo-thermal conversion efficiency (82.4%) and a simultaneous reactive oxygen species (ROS) generation effect. Meanwhile, HMON@CuS/Gd could efficiently enter GC cells, induce combined mild PTT (43-45 °C) and PDT under mild NIR power density (0.8 W/cm2). Surprisingly, it was found that PTT might not be the only factor of cell apoptosis, as ROS induced by PDT also seemed playing an essential role. The NIR-induced ROS could attack mitochondrial transmembrane potentials (MTPs), then promote mitochondrial reactive oxygen species (mitoROS) production. Meanwhile, mitochondrial damage dramatically changed the expression of anti-apoptotic protein (Bcl-2) and pro-apoptotic protein (Bax). Since that, mitochondrial permeability transition pore (mPTP) was opened, followed by inducing more cytochrome c (Cyto C) releasing from mitochondria into cytosol, and finally activated caspase-9/caspase-3-depended cell apoptosis pathway. Our in vivo data also showed that HMON@CuS/Gd exhibited good fluorescence (FL) imaging (wrapping fluorescent agent), enhanced T1 imaging under magnetic resonance imaging (MRI) and infrared thermal (IRT) imaging capacities. Guided by FL/MRI/IRT trimodal imaging, HMON@CuS/Gd could selectively cause mild photo-therapy at cancer region, efficiently inhibit the growth of GC cells without evident systemic toxicity in vivo. CONCLUSION: HMON@CuS/Gd could serve as a promising multifunctional nanotheranostic platform and as a cancer photo-therapy agent through inducing mitochondrial dysfunction on GC.
Assuntos
Mitocôndrias , Imagem Multimodal/métodos , Compostos de Organossilício , Fototerapia/métodos , Neoplasias Gástricas , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sulfato de Cobre , Humanos , Imageamento por Ressonância Magnética , Mitocôndrias/patologia , Mitocôndrias/efeitos da radiação , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/patologia , Neoplasias Gástricas/terapia , Nanomedicina TeranósticaRESUMO
Polyhedral oligomeric silsesquioxane (POSS) is a promising scaffold to be used as delivery system. POSS can modify the properties of photosensitizers to enhance their efficacy toward photodynamic therapy (PDT). In this work, we designed, synthesized and characterized five different POSS porphyrin (POSSPs 1-5) derivatives containing hydrophobic (1-3) and hydrophilic (4 and 5) functional groups. In general, all the POSSPs showed a better singlet oxygen quantum yield than the parent porphyrins due to the steric hindrance from the POSS unique structure. POSSPs 1 and 3 containing isobutyl groups showed better PDT performance in cancer cells at lower concentrations than POSSPs 4 and 5. However; at higher concentrations, the POSSP4 containing hydrophilic groups has an enhanced PDT efficiency as compared with the parent porphyrin. We envision that the chemical tunability of POSSs can be used as a promising option to improve the delivery and performance of photosensitizers.
Assuntos
Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Polimerização , Porfirinas/química , Linhagem Celular Tumoral , Humanos , Compostos de Organossilício/síntese química , Fármacos Fotossensibilizantes/síntese químicaRESUMO
Anionic carbosilane dendrimers such as G2-S16 are very effective in preventing HSV-2 infection both in vitro and in vivo. We present the main achievements obtained for the G2-S16 dendrimer in vivo, especially related to its efficacy against HSV-2 infection. Moreover, we discuss the mechanisms by which the G2-S16 dendrimer applied vaginally as a topical microbicide has been demonstrated to be safe and harmless for the vaginal microbiome balance, as both conditions present an essential step that has to be overcome during microbicide development. This review points to the marked protective effect of the G2-S16 dendrimer against sexually transmitted HSV-2 infection, supporting its role as a possible microbicide against HSV-2 infection.
Assuntos
Alcanossulfonatos/uso terapêutico , Dendrímeros/uso terapêutico , Herpes Genital/prevenção & controle , Herpesvirus Humano 2/efeitos dos fármacos , Compostos de Organossilício/uso terapêutico , Administração Tópica , Alcanossulfonatos/farmacologia , Animais , Ensaios Clínicos como Assunto , Dendrímeros/farmacologia , Humanos , Compostos de Organossilício/farmacologia , Resultado do TratamentoRESUMO
Organic-inorganic oligo(ethylene glycol)-polyhedral oligomeric silsesquioxanes (OEGn-POSS) hybrid materials are woven into macroscopically shaped entities by thiol-ene chemistry. The mechanical behavior and interfacial nature of the OEGn-POSS materials are easily tailored by changing the length of OEGn. The nanostructured OEGn-POSS materials exhibited excellent bioactivity to form hydroxyapatite, whose morphology was also dependent on the molecular weight of OEGn. Among them, OEG2-POSS materials enhanced the in vitro differentiation of adipose-derived stem cells to osteoblasts and promoted the in vivo bone formation within a femoral condyle defect site, but they could be limited by the mismatch rates between the degradation and new bone formation. Thus, OEG2-POSS could be practically applied for bone regeneration by optimizing the degradation rate based on its key structural features, which would be of great benefit to bone tissue engineering in the future.