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1.
Int J Mol Sci ; 24(9)2023 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-37176099

RESUMO

Smart pH-responsive niosomes loaded with either Oxaliplatin (Ox), Ylang ylang essential oil (Y-oil), or co-loaded with both compounds (Ox-Y) (Ox@NSs, Y@NSs, and Ox-Y@NSs, respectively) were formulated utilizing the thin film method. The developed nanocontainers had a spherical morphology with mean particle sizes lower than 170 nm and showed negative surface charges, high entrapment efficiencies, and a pH-dependent release over 24 h. The prepared pH-responsive niosomes' cytotoxicity was tested against the invasive triple-negative breast cancer (MDA-MB-231) cells, compared to free OX and Y-oil. All niosomal formulations loaded with Ox and/or Y-oil significantly improved cytotoxic activity relative to their free counterparts. The Ox-Y@NSs demonstrated the lowest IC50 (0.0002 µg/mL) when compared to Ox@NSs (0.006 µg/mL) and Y@NSs (18.39 µg/mL) or unloaded Ox (0.05 µg/mL) and Y-oil (29.01 µg/mL). In addition, the percentages of the MDA-MB-231 cell population in the late apoptotic and necrotic quartiles were profoundly higher in cells treated with the smart Ox-Y@NSs (8.38% and 5.06%) than those exposed to free Ox (7.33% and 1.93%) or Y-oil (2.3% and 2.13%) treatments. Gene expression analysis and protein assays were performed to provide extra elucidation regarding the molecular mechanism by which the prepared pH-sensitive niosomes induce apoptosis. Ox-Y@NSs significantly induced the gene expression of the apoptotic markers Tp53, Bax, and Caspase-7, while downregulating the antiapoptotic Bcl2. As such, Ox-Y@NSs are shown to activate the intrinsic pathway of apoptosis. Moreover, the protein assay ascertained the apoptotic effects of Ox-Y@NSs, generating a 4-fold increase in the relative protein quantity of the late apoptotic marker Caspase-7. Our findings suggest that combining natural essential oil with synthetic platinum-based drugs in pH-responsive nanovesicles is a promising approach to breast cancer therapy.


Assuntos
Antineoplásicos , Cananga , Óleos Voláteis , Neoplasias de Mama Triplo Negativas , Humanos , Oxaliplatina/farmacologia , Caspase 7 , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Lipossomos , Óleos Voláteis/farmacologia , Óleos de Plantas , Antineoplásicos/farmacologia , Concentração de Íons de Hidrogênio
2.
Molecules ; 28(23)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38067437

RESUMO

(1) Background: DA-Gelucire® 50/13-based solid lipid nanoparticles (SLNs) administering the neurotransmitter dopamine (DA) and the antioxidant grape-seed-derived proanthocyanidins (grape seed extract, GSE) have been prepared by us in view of a possible application for Parkinson's disease (PD) treatment. To develop powders constituted by such SLNs for nasal administration, herein, two different agents, namely sucrose and methyl-ß-cyclodextrin (Me-ß-CD), were evaluated as cryoprotectants. (2) Methods: SLNs were prepared following the melt homogenization method, and their physicochemical features were investigated by Raman spectroscopy, Scanning Electron Microscopy (SEM), atomic force microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). (3) Results: SLN size and zeta potential values changed according to the type of cryoprotectant and the morphological features investigated by SEM showed that the SLN samples after lyophilization appear as folded sheets with rough surfaces. On the other hand, the AFM visualization of the SLNs showed that their morphology consists of round-shaped particles before and after freeze-drying. XPS showed that when sucrose or Me-ß-CD were not detected on the surface (because they were not allocated on the surface or completely absent in the formulation), then a DA surfacing was observed. In vitro release studies in Simulated Nasal Fluid evidenced that DA release, but not the GSE one, occurred from all the cryoprotected formulations. Finally, sucrose increased the physical stability of SLNs better than Me-ß-CD, whereas RPMI 2650 cell viability was unaffected by SLN-sucrose and slightly reduced by SLN-Me-ß-CD. (4) Conclusions: Sucrose can be considered a promising excipient, eliciting cryoprotection of the investigated SLNs, leading to a powder nasal pharmaceutical dosage form suitable to be handled by PD patients.


Assuntos
Extrato de Sementes de Uva , Nanopartículas , Humanos , Extrato de Sementes de Uva/farmacologia , Dopamina , Pós , Nanopartículas/química , Crioprotetores , Liofilização/métodos , Sacarose/química , Tamanho da Partícula
3.
Small ; 18(18): e2107768, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35355412

RESUMO

Formulations based on ionizable amino-lipids have been put into focus as nucleic acid delivery systems. Recently, the in vitro efficacy of the lipid formulation OH4:DOPE has been explored. However, in vitro performance of nanomedicines cannot correctly predict in vivo efficacy, thereby considerably limiting pre-clinical translation. This is further exacerbated by limited access to mammalian models. The present work proposes to close this gap by investigating in vivo nucleic acid delivery within simpler models, but which still offers physiologically complex environments and also adheres to the 3R guidelines (replace/reduce/refine) to improve animal experiments. The efficacy of OH4:DOPE as a delivery system for nucleic acids is demonstrated using in vivo approaches. It is shown that the formulation is able to transfect complex tissues using the chicken chorioallantoic membrane model. The efficacy of DNA and mRNA lipoplexes is tested extensively in the zebra fish (Danio rerio) embryo which allows the screening of biodistribution and transfection efficiency. Effective transfection of blood vessel endothelial cells is seen, especially in the endocardium. Both model systems allow an efficacy screening according to the 3R guidelines bypassing the in vitro-in vivo gap. Pilot studies in mice are performed to correlate the efficacy of in vivo transfection.


Assuntos
Ácidos Nucleicos , Animais , Células Endoteliais , Lipídeos , Lipossomos , Mamíferos , Camundongos , Nanoestruturas , Peptídeos , Distribuição Tecidual , Transfecção
4.
Mediators Inflamm ; 2022: 8886087, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36081652

RESUMO

Background: Guttiferone E is a naturally occurring polyisoprenylated benzophenone exhibiting a wide range of remarkable biological activities. But its therapeutic application is still limited due to its poor water solubility. This study is aimed at preparing guttiferone E-loaded liposomes and assessing their in vitro cytotoxicity and anti-inflammatory effect. Methods: Liposomes containing guttiferone E were prepared by the thin film hydration method, and the physicochemical characteristics were determined using dynamic light scattering, laser Doppler velocimetry, and atomic force microscopy. The cytotoxicity was assessed by the MTT assay. The fluorometric cyclooxygenase (COX) activity assay kit was used to assess the COX activity while the nitric oxide production was evaluated by the Griess reagent method. Results: The liposomes with a mean size of 183.33 ± 17.28 nm were obtained with an entrapment efficiency of 63.86%. Guttiferone E-loaded liposomes successfully decreased the viability of cancer cells. The overall IC50 values varied between 5.46 µg/mL and 22.25 µg/mL. Compared to the untreated control, guttiferone E-loaded liposomes significantly reduced the nitric oxide production and the activity of COX in a concentration-dependent manner. Conclusion: This study indicates that liposomes can be an alternative to overcome the water insolubility issue of the bioactive guttiferone E.


Assuntos
Lipossomos , Neoplasias , Anti-Inflamatórios/farmacologia , Benzofenonas/farmacologia , Humanos , Lipopolissacarídeos/farmacologia , Macrófagos , Óxido Nítrico , Tamanho da Partícula , Água
5.
Langmuir ; 36(17): 4808-4819, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32306733

RESUMO

With the intention to provide a robust and economical model that can be used for predicting particle interactions with the pulmonary surfactant, this study was aimed to find an artificial surfactant model that perfectly mimics the properties of the natural pulmonary surfactant. A surfactant model should be reproducible, robust, and able to predict interactions between the pulmonary surfactant and exogenous influences from air and the aqueous site. We compared three synthetic models with the natural bovine surfactant Alveofact. The lung conditions were simulated by spreading the surfactants at the air/aqueous interface on a Langmuir trough with movable barriers. All three artificial surfactant models showed properties very similar to that of Alveofact. Visualization of the monolayers by atomic force microscopy revealed very similar structures with domain formation. The Tanaka lipid mixture has already shown good results in vitro and in vivo in previous studies. The 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)-1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) model has large conformations in the surface pressure isotherms and showed a biomimetic exclusion plateau, indicative of an effective lung surfactant formulation. Also, the equilibrium spreading pressure was similar. DPPC-1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-1'-rac-glycerol (POPG) had the greatest similarities with Alveofact in the hysteresis areas. The kinetic constants of the relaxation experiments during desorption showed that the PCPG model (at 30 mN/m) had almost identical diffusion and dissolution values as Alveofact. As a proof of concept, the interaction of the models with PLGA nanoparticles showed promising results in all experiments for all the three surfactant models. The results show that the choice of components in a model play a crucial role in obtaining reproducible results. The selected models can be used for further studies as synthetic in vitro lung models.

6.
Eur Arch Otorhinolaryngol ; 277(10): 2893-2906, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32488381

RESUMO

BACKGROUND: The histological differentiation of individual types of vascular anomalies (VA), such as lymphatic malformations (LM), hemangioma (Hem), paraganglioma (PG), venous malformations (VeM), arteriovenous malformations (AVM), pyogenic granulomas (GP), and (not otherwise classified) vascular malformations (VM n.o.c.) is frequently difficult due to the heterogeneity of these anomalies. The aim of the study was to evaluate digital image analysis as a method for VA stratification METHODS: A total of 40 VA tissues were examined immunohistologically using a selection of five vascular endothelial-associated markers (CD31, CD34, CLDN5, PDPN, VIM). The staining results were documented microscopically followed by digital image analyses based quantification of the candidate-marker-proteins using the open source program ImageJ/Fiji. RESULTS: Differences in the expression patterns of the candidate proteins could be detected particularly when deploying the quotient of the quantified immunohistochemical signal values. Deploying signal marker quotients, LM could be fully distinguished from all other tested tissue types. GP achieved stratification from LM, Hem, VM, PG and AVM tissues, whereas Hem, PG, VM and AVM exhibited significantly different signal marker quotients compared with LM and GP tissues. CONCLUSION: Although stratification of different VA from each other was only achieved in part with the markers used, the results of this study strongly support the usefulness of digital image analysis for the stratification of VA. Against the background of upcoming new diagnostic techniques involving artificial intelligence and deep (machine) learning, our data serve as a paradigm of how digital evaluation methods can be deployed to support diagnostic decision making in the field of VAs.


Assuntos
Hemangioma , Malformações Vasculares , Inteligência Artificial , Cabeça , Hemangioma/diagnóstico por imagem , Humanos , Pescoço , Malformações Vasculares/diagnóstico por imagem
7.
Molecules ; 25(21)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33126464

RESUMO

Platinum nanoparticles (PtNPs) have superior physicochemical properties and great potential in biomedical applications. Eco-friendly and economic approaches for the synthesis of PtNPs have been developed to overcome the shortcomings of the traditional physical and chemical methods. Various biogenic entities have been utilized in the green synthesis of PtNPs, including mainly plant extracts, algae, fungi bacteria, and their biomedical effects were assessed. Other biological derivatives have been used in the synthesis of PtNPs such as egg yolk, sheep milk, honey, and bovine serum albumin protein. The green approaches for the synthesis of PtNPs have reduced the reaction time, the energy required, and offered ambient conditions of fabrication. This review highlights the state-of-the-art methods used for green synthesis of PtNPs, synthesis parameters, and their reported biomedical applications.


Assuntos
Pesquisa Biomédica , Técnicas de Química Sintética/métodos , Química Verde/métodos , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Platina/química , Humanos
8.
Molecules ; 25(24)2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33327642

RESUMO

P-sulfonatocalix[n]arenes have demonstrated a great potential for encapsulation of therapeutic drugs via host-guest complexation to improve solubility, stability, and bioavailability of encapsulated drugs. In this work, guest-host complexes of a third-generation anticancer drug (oxaliplatin) and p-4-sulfocalix[n]arenes (n = 4 and 6; p-SC4 and p-SC6, respectively) were prepared and investigated, using 1H NMR, UV, Job's plot analysis, and DFT calculations, for use as cancer therapeutics. The peak amplitude of the prepared host-guest complexes was linearly proportional to the concentration of oxaliplatin in the range of 1.0 × 10-5 M-1 to 2.1 × 10-4 M-1. The reaction stoichiometry between either p-SC4 or p-SC6 and oxaliplatin in the formed complexes was 1:1. The stability constants for the complexes were 5.07 × 104 M-1 and 6.3 × 104 M-1. These correspond to complexation free energy of -6.39 and -6.52 kcal/mol for p-SC4 and p-SC6, respectively. Complexation between oxaliplatin and p-SC4 or p-SC6 was found to involve hydrogen bonds. Both complexes exhibited enhanced biological and high cytotoxic activities against HT-29 colorectal cells and MCF-7 breast adenocarcinoma compared to free oxaliplatin, which warrants further investigation for cancer therapy.


Assuntos
Antineoplásicos/síntese química , Sulfonatos de Arila/síntese química , Calixarenos/síntese química , Composição de Medicamentos/métodos , Oxaliplatina/farmacologia , Antineoplásicos/metabolismo , Sulfonatos de Arila/metabolismo , Calixarenos/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células HT29 , Humanos , Ligação de Hidrogênio , Concentração Inibidora 50 , Cinética , Células MCF-7 , Modelos Químicos , Oxaliplatina/metabolismo , Teoria Quântica , Termodinâmica
9.
Photochem Photobiol Sci ; 18(2): 304-308, 2019 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-30620037

RESUMO

Photodynamic therapy is one of the most promising non-invasive strategies employed for the treatment of several kinds of bacterial infections. Though the vast majority of clinically approved photosensitisers are administered intravenously, most of the in vitro experiments are performed under static conditions which do not represent the physiological environment of the venous bloodstream. To address this issue, a dynamic circulation model was developed to facilitate in situ antibacterial photodynamic therapy under flow conditions to mimic blood stream infections.


Assuntos
Bacteriemia/tratamento farmacológico , Fotoquimioterapia/métodos , Humanos , Teste de Materiais , Nanopartículas/efeitos adversos , Nanopartículas/química
10.
Org Biomol Chem ; 17(7): 1827-1833, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30604825

RESUMO

We report a high-affinity photoswitchable DNA binder, which displays different nucleosome-binding capacities upon visible-light irradiation. Both photochemical and DNA-recognition properties were examined by UV-Vis, HPLC, CD spectroscopy, NMR, FID assays, EMSA and DLS. Our probe sets the basis for developing new optoepigenetic tools for conditional modulation of nucleosomal DNA accessibility.


Assuntos
Compostos Azo/química , DNA/química , Substâncias Intercalantes/química , Luz , Nucleossomos/química , Compostos Azo/síntese química , Substâncias Intercalantes/síntese química , Estrutura Molecular , Processos Fotoquímicos
11.
Archaea ; 2017: 8047149, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28239294

RESUMO

Lipid vectors are commonly used to facilitate the transfer of nucleic acids into mammalian cells. In this study, two fractions of tetraether lipids from the archaea Sulfolobus acidocaldarius were extracted and purified using different methods. The purified lipid fractions polar lipid fraction E (PLFE) and hydrolysed glycerol-dialkyl-nonitol tetraether (hGDNT) differ in their structures, charge, size, and miscibility from conventional lipids. Liposomes were prepared by mixing tetraether lipids with cholesterol (CH) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) resulting in stable vectors for gene delivery. Lipoplexes were prepared by complexation of liposomes with a luciferase expressing plasmid (pCMV-luc) at certain nitrogen-to-phosphorus (N/P) ratios and optimised for the transient transfection of ovarian adenocarcinoma cells (SK-OV-3). Complexation efficacy was investigated by gel-red fluorescence assay. Biophysical properties, like size, surface charge, and morphology, were investigated by differential light scattering (DLS), atomic force microscopy (AFM), and scanning electron microscopy (Cryo-SEM), respectively, revealing structural differences between liposomes and lipoplexes. A range of stable transfecting agents containing tetraether lipids were obtained by incorporating 5 mol% of tetraether lipids. Lipoplexes showed a decrease in free gel-red with increasing N/P ratios indicating efficient incorporation of plasmid DNA (pDNA) and remarkable stability. Transfection experiments of the lipoplexes revealed successful and superior transfection of SK-OV-3 cell line compared to the commercially available DOTAP and branched polyethyleneimine (25 kDa bPEI).


Assuntos
Lipídeos/química , Lipossomos/química , Sulfolobus acidocaldarius/química , Transfecção/métodos , Linhagem Celular Tumoral , Humanos
12.
Langmuir ; 33(39): 10172-10183, 2017 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-28873311

RESUMO

Four different binary lipid mixtures composed of a cationic lipid and the zwitterionic colipids DOPE or DPPC, which show different DNA transfer activities in cell culture models, were investigated at the soft air/water interface to identify transfection efficiency determining characteristics. Langmuir films are useful models to investigate the interaction between DNA and lipid mixtures in a two-dimensional model system by using different surface sensitive techniques, namely, epifluorescence microscopy and infrared reflection-absorption spectroscopy. Especially, the effect of adsorbed DNA on the properties of the lipid mixtures has been examined. Distinct differences between the lipid composites were found which are caused by the different colipids of the mixtures. DOPE containing lipid mixtures form fluid monolayers with a uniform distribution of the fluorescent probe in the presence and absence of DNA at physiologically relevant surface pressures. Only at high nonphysiological pressures, the lipid monolayer collapses and phase separation was observed if DNA was present in the subphase. In contrast, DPPC containing lipid mixtures show domains in the liquid condensed phase state in the presence and absence of DNA in the subphase. The adsorption of DNA at the positively charged mixed lipid monolayer induces phase separation which is expressed in the morphology and the point of appearance of these domains.


Assuntos
DNA/química , 1,2-Dipalmitoilfosfatidilcolina , Adsorção , Cátions , Lipídeos , Propriedades de Superfície
13.
J Nanobiotechnology ; 15(1): 23, 2017 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-28330480

RESUMO

BACKGROUND: The adhesion of cells to an oscillating cantilever sensitively influences the oscillation amplitude at a given frequency. Even early stages of cytotoxicity cause a change in the viscosity of the cell membrane and morphology, both affecting their adhesion to the cantilever. We present a generally applicable method for real-time, label free monitoring and fast-screening technique to assess early stages of cytotoxicity recorded in terms of loss of cell adhesion. RESULTS: We present data taken from gold nanoparticles of different sizes and surface coatings as well as some reference substances like ethanol, cadmium chloride, and staurosporine. Measurements were recorded with two different cell lines, HeLa and MCF7 cells. The results obtained from gold nanoparticles confirm earlier findings and attest the easiness and effectiveness of the method. CONCLUSIONS: The reported method allows to easily adapt virtually every AFM to screen and assess toxicity of compounds in terms of cell adhesion with little modifications as long as a flow cell is available. The sensitivity of the method is good enough indicating that even single cell analysis seems possible.


Assuntos
Adesão Celular , Sobrevivência Celular , Nanopartículas Metálicas/química , Microscopia de Força Atômica/métodos , Ouro/química , Células HeLa , Humanos , Células MCF-7
14.
Nanomedicine ; 13(1): 209-218, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27553077

RESUMO

Therapeutic applications of RNA interference (RNAi) require efficient siRNA delivery strategies in vivo. Combining lipid-based carriers with polymeric nanoparticles offers the favorable properties of both systems. This is the first study to explore polyethylenimine-based lipopolyplexes comprising a low-molecular weight PEI and the phospholipid DPPC for therapeutic siRNA use. Lipopolyplex structures are analyzed by electron microscopy. Biological efficacies are demonstrated in vitro by cellular uptake, knockdown of the target oncogene survivin, and concomitant cell growth inhibition. Upon systemic administration in tumor-bearing mice, here performed by intraperitoneal (i.p.) injection, radioactive biodistribution assays show lipopolyplex-mediated delivery of intact siRNAs. Absence of blood serum parameter alterations, erythrocyte aggregation or immunostimulation, and the observation of animal well-being and stable body weight confirm biocompatibility. Exploring therapeutic efficacies in a preclinical model, a considerable inhibition of prostate carcinoma xenograft growth is achieved, paralleled by an ~65% survivin knockdown in the tumors. We, thus, demonstrate that PEI-based lipopolyplexes represent an efficient platform for therapeutic use of small RNAs.


Assuntos
Lipossomos/química , Polietilenoimina/química , Interferência de RNA , RNA Interferente Pequeno/administração & dosagem , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias da Próstata/terapia , RNA Interferente Pequeno/uso terapêutico , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Gen Physiol Biophys ; 36(4): 471-479, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28836498

RESUMO

Liposomal carnosine could overcome the problems associated with direct application of this peptide. Anti-inflammatory and antioxidant effects of liposomal and non-liposomal carnosine in adjuvant arthritis were compared. The experiments were done on healthy animals, untreated arthritic animals, arthritic animals with oral administration of carnosine, and with subcutaneous administration of liposomal carnosine, both administered in the same daily dose of 150 mg/kg b.w. during 28 days. Carnosine reduced hind paw volume on day 28. Both forms markedly decreased interleukin-1ß, matrix metalloproteinase-9 and monocyte chemoattractant protein-1 (MCP-1) in plasma on day 14. Only liposomal carnosine reduced significantly MCP-1. Malondialdehyde, 4-hydroxynonenal, resistance to Fe2+-induced oxidation and protein carbonyls were significantly corrected after administration of any form of carnosine. Liposomal carnosine corrected more effectively the oxidative stress in plasma than did carnosine. In brain tissue, our results showed protective ability of both forms of carnosine against oxidation of proteins and lipids. They also corrected the resistance to Fe2+-induced oxidation in arthritic animals. We found that only liposomal carnosine decreased the mRNA expression of inducible nitric oxide synthase in cartilage tissue. It can be concluded that the liposomal drug-delivery system is improving the pharmacological properties of carnosine administered in arthritis.


Assuntos
Artrite/tratamento farmacológico , Artrite/imunologia , Carnosina/administração & dosagem , Citocinas/imunologia , Animais , Artrite/induzido quimicamente , Carnosina/química , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Adjuvante de Freund , Lipossomos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/imunologia , Resultado do Tratamento
16.
Soft Matter ; 12(27): 5854-66, 2016 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-27328379

RESUMO

As a continuation of previous work, the self-assembly process of cationic lipid formulations in the presence and absence of DNA was investigated with respect to binary lipid mixtures suitable as polynucleotide carrier systems. The lipid blends consist of one malonic-acid-based cationic lipid with a varying alkyl chain pattern, either N-{6-amino-1-[N-(9Z)-octadec-9-enylamino]-1-oxohexan-(2S)-2-yl}-N'-{2-[N,N-bis(2-aminoethyl)amino]ethyl}-2-hexadecylpropandiamide () or N-[6-amino-1-oxo-1-(N-tetradecylamino)hexan-(2S)-2-yl]-N'-{2-[N,N-bis(2-aminoethyl)amino]ethyl}-2-hexadecylpropandiamide (), and one neutral co-lipid, either 1,2-di-[(9Z)-octadec-9-enoyl]-sn-glycero-3-phosphocholine (DOPE) or 1,2-di-(hexadecanoyl)-sn-glycero-3-phosphocholine (DPPC). Although the cationic lipids exhibit only slight differences in their structure, the DNA transfer efficiency varies drastically. Therefore, self-assembly was studied in 3D systems by small- and wide-angle X-ray scattering (SAXS and WAXS) and transmission electron microscopy (TEM) as well as in 2D systems by infrared reflection-absorption spectroscopy (IRRAS) on Langmuir films. The investigated lipid mixtures show quite different self-assembly in the absence of DNA, with varying structures from vesicles (/DOPE; /DOPE) and tubes (/DOPE) to discoid structures (/DPPC; /DPPC). Twisted ribbons and sheets, which were stabilized due to hydrogen-bond networks, were found in all investigated lipid mixtures in the absence of DNA. The addition of DNA leads to the formation of lamellar lipoplexes for all the investigated lipid compositions. The lipoplexes differ in crucial parameters, such as the lamellar repeat distance and the spacing between the DNA strands, indicating differences in the binding strength between DNA and the lipid composition. The formation of associates with an ideal charge density might emerge as a key parameter for efficient DNA transfer. Furthermore, the structures observed for the different lipid compositions in the absence of DNA prepare the way for other applications besides gene therapy.


Assuntos
Malonatos/química , Fosfolipídeos/química , Cátions , DNA/química , Diamida , Lipossomos , Espalhamento de Radiação , Transfecção , Difração de Raios X
17.
Bioconjug Chem ; 26(12): 2461-73, 2015 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-26471337

RESUMO

In the present work, we characterize binary lipid mixtures consisting of a three-chain amino-functionalized cationic lipid (DiTT4) with different phospholipids, namely, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), or 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). The mixing behavior was investigated by differential scanning calorimetry (DSC). Additionally, aqueous dispersions of the binary mixtures were characterized by means of dynamic light scattering (DLS), laser Doppler electrophoresis, and transmission electron microscopy (TEM) to get further information about particle size, charge, and shape. The complex formation between different binary lipid mixtures and plasmid DNA (pDNA) was investigated by zeta-(ζ)-potential (laser Doppler electrophoresis) and DLS measurements, and the lipid/DNA complexes (lipoplexes) were screened for efficient DNA transfer (transfection) in cell culture. Finally, efficient lipid compositions were investigated with respect to serum stability. This work provides a detailed characterization of the cationic lipid mixtures as foundation for further research. Efficient gene transfer in the presence of serum was demonstrated for selected lipoplexes showing their capability to be used as high-potency gene delivery vehicles.


Assuntos
DNA/administração & dosagem , Dimiristoilfosfatidilcolina/química , Fosfatidiletanolaminas/química , Plasmídeos/administração & dosagem , Transfecção , Cátions/química , Linhagem Celular , DNA/genética , Técnicas de Transferência de Genes , Células HeLa , Humanos , Tamanho da Partícula , Plasmídeos/genética
18.
Inorg Chem ; 53(14): 7642-9, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-24992258

RESUMO

A new chiral [Ni15] complex with a Schiff-base ligand derived from o-vanillin and L-glutamic acid is presented, emphasizing the properties relevant for biology and materials science. The formation of the complex molecules in solution is confirmed by AFM and dynamic light scattering studies. The compound is weakly antiferromagnetic with considerable admixture of excited states, comprising negligibly interacting [Ni3] units. Studies of the interactions with two cell lines indicate low cytotoxicity.


Assuntos
Níquel/química , Luz , Microscopia de Força Atômica , Níquel/toxicidade , Espalhamento de Radiação , Espectrometria por Raios X , Espectrofotometria Infravermelho , Estereoisomerismo
19.
Colloids Surf B Biointerfaces ; 241: 114059, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38941652

RESUMO

In cancer research, circulating tumor cells (CTCs) were identified as the main drivers of metastasis. They are vital for early detection and prevention of metastasis during cancer treatment. Even though continuous progress in research offers more and more tools to combat cancer, we still lack a proper arsenal of therapeutics. Especially in tumors with close to no targeting options, like triple-negative breast cancer, early detection is often the main difference between successful and failed therapy. When such tumors are detected too late, they may have already produced plenty of CTCs, likely causing metastasis, which is the primary reason for tumor-associated deaths. Detecting those CTCs early on could substantially impact therapy outcomes and the 5-year survival rate. In our study, we developed and evaluated a reliable and affordable CTC screening method based on flow cytometry and 5-aminolevulinic acid (5-ALA) staining. We successfully established a circulation model for 5-ALA and CTCs research and demonstrated that the method can detect an average of 11 ±â€¯3.3 CTCs out of 10,000 peripheral blood mononuclear cells, representing as low as approximately 0.1 % with a reasonable number of false positive events. Additionally, we present initial results on a theranostic approach using 5-ALA converted to protoporphyrin IX. The outcomes of this study might contribute significantly to the further development of CTC detection and the overall detection and treatment of cancer.

20.
Biomater Adv ; 159: 213823, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38460353

RESUMO

Lung cancer, one of the most common causes of high mortality worldwide, still lacks appropriate and convenient treatment options. Photodynamic therapy (PDT) has shown promising results against cancer, especially in recent years. However, pulmonary drug delivery of the predominantly hydrophobic photosensitizers still represents a significant obstacle. Nebulizing DPPC/Cholesterol liposomes loaded with the photosensitizer curcumin via a vibrating mesh nebulizer might overcome current restrictions. In this study, the liposomes were prepared by conventional thin-film hydration and two other methods based on dual centrifugation. The liposomes' physicochemical properties were determined before and after nebulization, showing that liposomes do not undergo any changes. However, morphological characterization of the differently prepared liposomes revealed structural differences between the methods in terms of lamellarity. Internalization of curcumin in lung adenocarcinoma (A549) cells was visualized and quantified. The generation of reactive oxygen species because of the photoreaction was also proven. The photodynamic efficacy of the liposomal formulations was tested against A549 cells. They revealed different phototoxic responses at different radiant exposures. Furthermore, the photodynamic efficacy was investigated after nebulizing curcumin-loaded liposomes onto xenografted tumors on the CAM, followed by irradiation, and evaluated using positron emission tomography/computed tomography and histological analysis. A decrease in tumor metabolism could be observed. Based on the efficacy of curcumin-loaded liposomes in 2D and 3D models, liposomes, especially with prior film formation, can be considered a promising approach for PDT against lung cancer.


Assuntos
Curcumina , Neoplasias Pulmonares , Humanos , Lipossomos/uso terapêutico , Curcumina/farmacologia , Curcumina/uso terapêutico , Sistemas de Liberação de Medicamentos , Nebulizadores e Vaporizadores , Fármacos Fotossensibilizantes/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia
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