Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Materials (Basel) ; 16(7)2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37049199

RESUMO

Pancreatic ductal adenocarcinoma is a hard-to-treat, deadly malignancy. Traditional treatments, such as surgery, radiation and chemotherapy, unfortunately are still not able to significantly improve long-term survival. Three-dimensional (3D) cell cultures might be a platform to study new drug types in a highly reproducible, resource-saving model within a relevant pathophysiological cellular microenvironment. We used a 3D culture of human pancreatic ductal adenocarcinoma cell lines to investigate a potential new treatment approach using superparamagnetic iron oxide nanoparticles (SPIONs) as a drug delivery system for mitoxantrone (MTO), a chemotherapeutic agent. We established a PaCa DD183 cell line and generated PANC-1SMAD4 (-/-) cells by using the CRISPR-Cas9 system, differing in a prognostically relevant mutation in the TGF-ß pathway. Afterwards, we formed spheroids using PaCa DD183, PANC-1 and PANC-1SMAD4 (-/-) cells, and analyzed the uptake and cytotoxic effect of free MTO and MTO-loaded SPIONs by microscopy and flow cytometry. MTO and SPION-MTO-induced cell death in all tumor spheroids in a dose-dependent manner. Interestingly, spheroids with a SMAD4 mutation showed an increased uptake of MTO and SPION-MTO, while at the same time being more resistant to the cytotoxic effects of the chemotherapeutic agents. MTO-loaded SPIONs, with their ability for magnetic drug targeting, could be a future approach for treating pancreatic ductal adenocarcinomas.

2.
Cancer Med ; 11(24): 4743-4755, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35578404

RESUMO

BACKGROUND: Extramedullary plasmacytoma (EMP) is a solitary tumor consisting of neoplastic plasma cells, with very little to no bone marrow involvement. EMPs are usually located in the head and neck region, but can also occur along the digestive tract, in lungs, or extremities. METHODS: Following our publication on EMP, which appeared in 1999 (Cancer 85:2305-14), we conducted a literature search for EMP-related reports published between 1999 and 2021. The documented cases, as well as 14 of our own patients from the ENT Clinic Erlangen, were extensively analyzed. RESULTS: Between 1998 and 2021, 1134 patients with EMP were reported, for whom information about the tumor localization was available. Among those, 62.4% had EMP in the head and neck area and 37.6% in other body regions. Data on therapy were reported in 897 patients, including 34.3% who received radiation, 28.1% surgery, 22.6% a combination of surgery and radiation, and 15.9% another therapy. In 76.9% patients no recurrence or transformation to multiple myeloma (MM) was reported, 12.8% showed local recurrence and 10.2% developed MM. Radiotherapy alone was associated with a tendency for increased occurrence of MM. In patients with EMP of head and neck area, combination therapy (surgery and radiation) resulted in a 5-year overall survival rate of 98.3%, surgery alone of 92.4%, and radiotherapy of 92.7%. CONCLUSIONS: Collectively, our analyses indicate that surgical resection alone can achieve long-term tumor control in patients with EMP, if the tumor can be removed within safe limits without causing serious functional impairment. However, if this is not certain, either radiation or a combination of surgery and radiation therapy is suggested as an effective means of local tumor control.


Assuntos
Mieloma Múltiplo , Plasmocitoma , Humanos , Plasmocitoma/patologia , Seguimentos , Taxa de Sobrevida , Terapia Combinada
3.
Int J Mol Sci ; 20(18)2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514451

RESUMO

Pancreatic ductal adenocarcinoma (PDAC), generally known as pancreatic cancer (PC), ranks the fourth leading cause of cancer-related deaths in the western world. While the incidence of pancreatic cancer is displaying a rising tendency every year, the mortality rate has not decreased significantly because of late diagnosis, early metastasis, and limited reaction to chemotherapy or radiotherapy. Adjuvant chemotherapy after surgical resection is typically the preferred option to treat early pancreatic cancer. Although 5-fluorouracil/leucovorin with irinotecan and oxaliplatin (FOLFIRINOX) and gemcitabine/nab-paclitaxel can profoundly improve the prognosis of advanced pancreatic cancer, the development of chemoresistance still leads to poor clinical outcomes. Chemoresistance is multifactorial as a result of the interaction among pancreatic cancer cells, cancer stem cells, and the tumor microenvironment. Nevertheless, more pancreatic cancer patients will benefit from precision treatment and targeted drugs. Therefore, we outline new perspectives for enhancing the efficacy of gemcitabine after reviewing the related factors of gemcitabine metabolism, mechanism of action, and chemoresistance.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias Pancreáticas/patologia , Animais , Desoxicitidina/análogos & derivados , Desoxicitidina/química , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Genoma , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/terapia , Resultado do Tratamento , Microambiente Tumoral/efeitos dos fármacos , Gencitabina
4.
Tissue Eng Part A ; 25(21-22): 1470-1477, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30747035

RESUMO

Losing one's ability to speak, because of tissue deficiency at the vocal fold (VF), leads to serious impairment in the quality of life. Until now, there is no successful approach for regenerating the VF. The aim of this study was to show the advantage of magnetic nanoparticles in the generation of scaffold-free three-dimensional (3D) VF cell constructs by magnetic tissue engineering (MTE). Rabbit VF fibroblasts were used to establish MTE: after cellular uptake of superparamagnetic iron oxide nanoparticles (SPIONs), cells can be controlled with a magnetic field thereby forming solid 3D cell structures. To transfer this method into human cells, SPIONs were adapted accordingly and tested for their influence on human VF (hVF) cells and for their ability to perform MTE with hVF cells. Of interest, the cell number and the magnet's shape influence the form of the rabbit VF cell construct. After successful characterization of hVF cells, biocompatibility analyses revealed no significant influence of SPIONs on them, thus 3D hVF cell constructs could be successfully generated by MTE. These basic results are important to develop MTE as an innovative method to regenerate functional VFs. We expect that in vivo studies, including MTE as an elegant, far-field controlled and touchless technology, will translate MTE VF bioconstructs into reconstructive laryngeal medicine. Impact Statement This study aims at nanotechnology for regenerative medicine by magnetic tissue engineering (MTE). New approaches for vocal fold (VF) reconstruction are desperately needed. Superparamagnetic iron oxide nanoparticles offer innovative, scaffold-free potentials for tissue engineering: MTE. By using MTE we could generate functional multilayered human VF cell constructs, which can consequently be used to regenerate the voice in patients with VF injuries.


Assuntos
Compostos Férricos/química , Fenômenos Magnéticos , Nanopartículas de Magnetita/química , Engenharia Tecidual/métodos , Prega Vocal/fisiologia , Animais , Materiais Biocompatíveis/farmacologia , Humanos , Coelhos , Alicerces Teciduais/química
7.
Int J Mol Sci ; 18(7)2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28661430

RESUMO

The phototoxic effect of hypericin can be utilized for Photodynamic Therapy (PDT) of cancer. After intravenous application and systemic distribution of the drug in the patient's body, the tumor site is exposed to light. Subsequently, toxic reactive oxygen species (ROS) are generated, inducing tumor cell death. To prevent unwanted activation of the drug in other regions of the body, patients have to avoid light during and after the treatment cycles, consequently impairing quality of life. Here, we characterize toxicity and hypericin-mediated effects on cancer cells in vitro and confirm that its effect clearly depends on concentration and illumination time. To reduce side effects and to increase therapy success, selective accumulation of hypericin in the tumor region is a promising solution. Loading hypericin on superparamagnetic iron oxide nanoparticles (SPIONs) and guiding them to the desired place using an external magnetic field might accomplish this task (referred to as Magnetic Drug Targeting (MDT)). Thus, using a double targeting strategy, namely magnetic accumulation and laser induced photoactivation, might improve treatment effectivity as well as specificity and reduce toxic side effects in future clinical applications.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Perileno/análogos & derivados , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Administração Intravenosa , Antracenos , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Células HT29 , Humanos , Células Jurkat , Leucemia de Células T/tratamento farmacológico , Leucemia de Células T/metabolismo , Nanopartículas de Magnetita/administração & dosagem , Nanopartículas de Magnetita/química , Perileno/farmacocinética , Perileno/farmacologia , Fármacos Fotossensibilizantes/farmacocinética , Espécies Reativas de Oxigênio/metabolismo , Células Tumorais Cultivadas
8.
Nanoscale Res Lett ; 12(1): 284, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28431461

RESUMO

PURPOSE: The voice is the most important instrument of communication. Tissue defects in the vocal fold (VF) area lead to serious reduction in quality of life, but thus far, no satisfactory VF implant exists. Therefore, we aim to establish a functional VF implant in a rabbit model by magnetic tissue engineering (MTE) using superparamagnetic iron oxide nanoparticles (SPION). Hence, iron quantification over time as well as cell behavior studies upon SPION treatment are of great importance. METHODS: Rabbit VF fibroblasts (VFF) were treated with different concentrations of SPIONs (20, 40, and 80 µg/cm2), and iron content was examined for up to 40 days using microwave plasma-atom emission spectroscopy. The effects of SPION treatment on VFF (adhesion, spreading, and migration), which are important for the formation of 3D structures, were tested. RESULTS: Cellular SPION quantification revealed that there was no residual iron remaining in VFFs after 40 days. SPIONs had a dose-dependent effect on cell adhesion, with good tolerability observed up to 20 µg/cm2. Migration and spreading were not significantly influenced by SPION treatment up to 80 µg/cm2. DISCUSSION AND CONCLUSION: To develop 3D structures, cell behavior should not be affected by SPION uptake. After 40 days, cells were free of iron as a result of metabolism or rarefication during cell division. Cell functions including adhesion, spreading, and migration were proven to be intact in a dose-dependent manner after SPION treatment, suggesting a safe usage of MTE for voice rehabilitation. Our results thus constitute a solid basis for a successful transfer of this technique into 3D constructs, in order to provide an individual and personalized human VF implant in the future.

10.
Anticancer Res ; 36(6): 3085-91, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27272832

RESUMO

BACKGROUND/AIM: The voice is one of the most important instruments of communication between humans. It is the product of intact and well-working vocal folds. A defect of these structures causes dysphonia, associated with a clear reduction of quality of life. Tissue engineering of the vocal folds utilizing magnetic cell levitation after nanoparticle loading might be a technique to overcome this challenging problem. MATERIALS AND METHODS: Vocal fold fibroblasts (VFFs) were isolated from rabbit larynges and cultured. For magnetization, cells were incubated with superparamagnetic iron oxide nanoparticles (SPION) and the loading efficiency was determined by Prussian blue staining. Biocompatibility was analyzed in flow cytometry by staining with annexin V-fluorescein isothiocyanate propidium iodide, 1,1',3,3,3',3'-hexamethylindodicarbo-cyanine iodide [DiIC1(5)] and propidium idodide-Triton X-100 to monitor phosphatidylserine exposure, plasma membrane integrity, mitochondrial membrane potential and DNA degradation. RESULTS: Isolated VFFs can be successfully loaded with SPION, and optimal iron loading associated with minimized cytotoxicity represents a balancing act in magnetic tissue engineering. CONCLUSION: Our data are a firm basis for the next steps of investigations. Magnetic tissue engineering using magnetic nanoparticle-loaded cells which form three-dimensional structures in a magnetic field will be a promising approach in the future.


Assuntos
Compostos Férricos , Nanopartículas de Magnetita , Engenharia Tecidual/métodos , Prega Vocal/citologia , Distúrbios da Voz/reabilitação , Animais , Células Cultivadas , Fibroblastos/fisiologia , Coelhos
11.
Anticancer Res ; 36(6): 3147-54, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27272840

RESUMO

BACKGROUND: Since superparamagnetic iron oxide nanoparticles (SPION) possess unique features, they provide a huge platform for medical applications, especially for cancer diagnosis and therapy (e.g. imaging, and drug targeting). However, heterogeneous effects on mammalian cells with regard to reproductive tissue are described. An experimental study was carried out to study the effects of SPIONs on both the expression of steroid hormone receptor and viability of granulosa cells, which play a key role in ovarian health and fertility. MATERIALS AND METHODS: Human granulosa cells were cultured in vitro and incubated with different concentrations of SPIONs. After 48 h, steroid receptor expression and cell viability were evaluated. RESULTS: Treatment of granulosa cells with SPIONs did not affect estrogen receptor ß1 or progesterone receptor-A expression and had no significant effect on cell viability. CONCLUSION: Nanoparticles precoated with bovine serum albumin (BSA) do not alter granulosa cell phenotype, whereas literature suggests that other nanoparticles induce apoptosis and reduce steroid receptor expression. Our data indicate an overall better outcome using SPIONs coated with BSA.


Assuntos
Compostos Férricos/farmacologia , Células da Granulosa/efeitos dos fármacos , Nanopartículas de Magnetita/administração & dosagem , Soroalbumina Bovina/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Compostos Férricos/administração & dosagem , Células da Granulosa/química , Humanos , Receptores de Estrogênio/análise
13.
Eur J Pharm Biopharm ; 101: 152-62, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26854862

RESUMO

In this work we present a new formulation of superparamagnetic iron oxide nanoparticles (SPIONs) for magnetic drug targeting. The particles were reproducibly synthesized from current good manufacturing practice (cGMP) - grade substances. They were surface coated using fatty acids as anchoring molecules for human serum albumin. We comprehensively characterized the physicochemical core-shell structure of the particles using sophisticated methods. We investigated biocompatibility and cellular uptake of the particles using an established flow cytometric method in combination with microwave-plasma assisted atomic emission spectroscopy (MP-AES). The cytotoxic drug mitoxantrone was adsorbed on the protein shell and we showed that even in complex media it is slowly released with a close to zero order kinetics. We also describe an in vitro proof-of-concept assay in which we clearly showed that local enrichment of this SPION-drug conjugate with a magnet allows site-specific therapeutic effects.


Assuntos
Compostos Férricos/química , Nanopartículas/química , Albumina Sérica/química , Materiais Biocompatíveis/química , Linhagem Celular Tumoral , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos , Humanos , Células Jurkat , Magnetismo/métodos , Microscopia de Força Atômica/métodos , Mitoxantrona/química
14.
Int J Mol Sci ; 16(11): 26280-90, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26540051

RESUMO

Nanoparticles that are aimed at targeting cancer cells, but sparing healthy tissue provide an attractive platform of implementation for hyperthermia or as carriers of chemotherapeutics. According to the literature, diverse effects of nanoparticles relating to mammalian reproductive tissue are described. To address the impact of nanoparticles on cyto- and genotoxicity concerning the reproductive system, we examined the effect of superparamagnetic iron oxide nanoparticles (SPIONs) on granulosa cells, which are very important for ovarian function and female fertility. Human granulosa cells (HLG-5) were treated with SPIONs, either coated with lauric acid (SEONLA) only, or additionally with a protein corona of bovine serum albumin (BSA; SEON(LA-BSA)), or with dextran (SEON(DEX)). Both micronuclei testing and the detection of γH2A.X revealed no genotoxic effects of SEON(LA-BSA), SEON(DEX) or SEON(LA). Thus, it was demonstrated that different coatings of SPIONs improve biocompatibility, especially in terms of genotoxicity towards cells of the reproductive system.


Assuntos
Dextranos/toxicidade , Compostos Férricos/toxicidade , Células da Granulosa/efeitos dos fármacos , Nanopartículas de Magnetita/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Dextranos/metabolismo , Feminino , Compostos Férricos/metabolismo , Células da Granulosa/metabolismo , Humanos , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Testes de Mutagenicidade
15.
Biochem Biophys Res Commun ; 468(3): 463-70, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26271592

RESUMO

Nanoparticles have belonged to various fields of biomedical research for quite some time. A promising site-directed application in the field of nanomedicine is drug targeting using magnetic nanoparticles which are directed at the target tissue by means of an external magnetic field. Materials most commonly used for magnetic drug delivery contain metal or metal oxide nanoparticles, such as superparamagnetic iron oxide nanoparticles (SPIONs). SPIONs consist of an iron oxide core, often coated with organic materials such as fatty acids, polysaccharides or polymers to improve colloidal stability and to prevent separation into particles and carrier medium [1]. In general, magnetite and maghemite particles are those most commonly used in medicine and are, as a rule, well-tolerated. The magnetic properties of SPIONs allow the remote control of their accumulation by means of an external magnetic field. Conjugation of SPIONs with drugs, in combination with an external magnetic field to target the nanoparticles (so-called "magnetic drug targeting", MDT), has additionally emerged as a promising strategy of drug delivery. Magnetic nanoparticle-based drug delivery is a sophisticated overall concept and a multitude of magnetic delivery vehicles have been developed. Targeting mechanism-exploiting, tumor-specific attributes are becoming more and more sophisticated. The same is true for controlled-release strategies for the diseased site. As it is nearly impossible to record every magnetic nanoparticle system developed so far, this review summarizes interesting approaches which have recently emerged in the field of targeted drug delivery for cancer therapy based on magnetic nanoparticles.


Assuntos
Antineoplásicos/administração & dosagem , Preparações de Ação Retardada/administração & dosagem , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/efeitos da radiação , Nanocápsulas/química , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/efeitos da radiação , Preparações de Ação Retardada/química , Preparações de Ação Retardada/efeitos da radiação , Humanos , Campos Magnéticos , Nanopartículas de Magnetita/administração & dosagem , Nanocápsulas/administração & dosagem , Nanocápsulas/efeitos da radiação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA