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1.
J Am Chem Soc ; 146(30): 20550-20555, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39038812

RESUMO

A careful design of the nanocrystal architecture can strongly enhance the nanocrystal function. So far, this strategy has faced a synthetic bottleneck in the case of refractory oxides. Here we demonstrate the epitaxial growth of hafnia shells onto zirconia cores and pure zirconia shells onto europium-doped zirconia cores. The core/shell structures are fully crystalline. Upon shelling, the optical properties of the europium dopant are dramatically improved (featuring a more uniform coordination and a longer photoluminescence lifetime), indicating the suppression of nonradiative pathways. These results launch the stable zirconium and hafnium oxide hosts as alternatives for the established NaYF4 systems.

2.
Small ; : e2404309, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39246186

RESUMO

Understanding the localization and the interactions of biomolecules at the nanoscale and in the cellular context remains challenging. Electron microscopy (EM), unlike light-based microscopy, gives access to the cellular ultrastructure yet results in grey-scale images and averts unambiguous (co-)localization of biomolecules. Multimodal nanoparticle-based protein labels for correlative cathodoluminescence electron microscopy (CCLEM) and energy-dispersive X-ray spectromicroscopy (EDX-SM) are presented. The single-particle STEM-cathodoluminescence (CL) and characteristic X-ray emissivity of sub-20 nm lanthanide-doped nanoparticles are exploited as unique spectral fingerprints for precise label localization and identification. To maximize the nanoparticle brightness, lanthanides are incorporated in a low-phonon host lattice and separated from the environment using a passivating shell. The core/shell nanoparticles are then functionalized with either folic (terbium-doped) or caffeic acid (europium-doped). Their potential for (protein-)labeling is successfully demonstrated using HeLa cells expressing different surface receptors that bind to folic or caffeic acid, respectively. Both particle populations show single-particle CL emission along with a distinctive energy-dispersive X-ray signal, with the latter enabling color-based localization of receptors within swift imaging times well below 2 min per µ m $\umu\text{m}$ 2 while offering high resolution with a pixel size of 2.78 nm. Taken together, these results open a route to multi-color labeling based on electron spectromicroscopy.

3.
Small ; 20(34): e2311115, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38556634

RESUMO

Engineering of catalytically active inorganic nanomaterials holds promising prospects for biomedicine. Catalytically active metal oxides show applications in enhancing wound healing but have also been employed to induce cell death in photodynamic or radiation therapy. Upon introduction into a biological system, nanomaterials are exposed to complex fluids, causing interaction and adsorption of ions and proteins. While protein corona formation on nanomaterials is acknowledged, its modulation of nanomaterial catalytic efficacy is less understood. In this study, proteomic analyses and nano-analytic methodologies quantify and characterize adsorbed proteins, correlating this protein layer with metal oxide catalytic activity in vitro and in vivo. The protein corona comprises up to 280 different proteins, constituting up to 38% by weight. Enhanced complement factors and other opsonins on nanocatalyst surfaces lead to their uptake into macrophages when applied topically, localizing >99% of the nanomaterials in tissue-resident macrophages. Initially, the formation of the protein corona significantly reduces the nanocatalysts' activity, but this activity can be partially recovered in endosomal conditions due to the proteolytic degradation of the corona. Overall, the research reveals the complex relationship between physisorbed proteins and the catalytic characteristics of specific metal oxide nanoparticles, providing design parameters for optimizing nanocatalysts in complex biological environments.


Assuntos
Óxidos , Coroa de Proteína , Óxidos/química , Animais , Catálise , Coroa de Proteína/química , Coroa de Proteína/metabolismo , Agregados Proteicos , Macrófagos/metabolismo , Camundongos , Metais/química , Humanos , Células RAW 264.7
4.
Artif Organs ; 47(8): 1309-1318, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36995348

RESUMO

BACKGROUND: Preeclampsia remains one of the most serious complications of pregnancy. Effective therapies are yet to be developed. Recent research has identified an imbalance of angiogenic and antiangiogenic factors as a root cause of preeclampsia. In particular, soluble fms-like tyrosine kinase-1 (sFlt-1) has been shown to bind the angiogenic factors vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), reducing blood vessel growth. Increasing preclinical and clinical evidence suggests that removal of the sFlt-1 protein may benefit patients with early onset preeclampsia. sFlt-1 may be removed by conventional blood purification techniques, such as therapeutic plasma exchange (TPE) and dextran sulfate apheresis (DSA), or emerging technologies, including extracorporeal magnetic blood purification (MBP). METHODS: We compare the performance and selectivity of TPE, DSA, and MBP for the therapeutic removal of sFlt-1. For MPB, we employ magnetic nanoparticles functionalized with either sFlt-1 antibodies or the sFlt-1-binding partner, vascular endothelial growth factor (VEGF). RESULTS: We demonstrate that sFlt-1 removal by MBP is feasible and significantly more selective than TPE and DSA at comparable sFlt-1 removal efficiencies (MBP 96%, TPE 92%, DSA 78%). During both TPE and DSA, complement factors (incl. C3c and C4) are depleted to a considerable extent (-90% for TPE, -55% for DSA), while in MBP, complement factor concentrations remain unaltered. We further demonstrate that the removal efficacy of sFlt-1 in the MBP approach is strongly dependent on the nanoparticle type and dose and can be optimized to reach clinically feasible throughputs. CONCLUSIONS: Taken together, the highly selective removal of sFlt-1 and potential other disease-causing factors by extracorporeal magnetic blood purification may offer new prospects for preeclamptic patients.


Assuntos
Remoção de Componentes Sanguíneos , Pré-Eclâmpsia , Gravidez , Humanos , Feminino , Fator A de Crescimento do Endotélio Vascular , Pré-Eclâmpsia/terapia , Troca Plasmática , Fator de Crescimento Placentário , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Sulfato de Dextrana , Remoção de Componentes Sanguíneos/métodos , Fenômenos Magnéticos
5.
NMR Biomed ; 35(6): e4690, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34994020

RESUMO

Microscopic magnetic field inhomogeneities caused by iron deposition or tissue-air interfaces may result in rapid decay of transverse magnetization in MRI. The aim of this study is to detect and quantify the distribution of iron-based nanoparticles in mouse models by applying ultrashort-echo-time (UTE) sequences in tissues exhibiting extremely fast transverse relaxation. In 24 C57BL/6 mice (two controls), suspensions containing either non-oxidic Fe or AuFeOx nanoparticles were injected into the tail vein at two doses (200 µg and 600 µg per mouse). Mice underwent MRI using a UTE sequence at 4.7 T field strength with five different echo times between 100 µs and 5000 µs. Transverse relaxation times T2 * were computed for the lung, liver, and spleen by mono-exponential fitting. In UTE imaging, the MRI signal could reliably be detected even in liver parenchyma exhibiting the highest deposition of nanoparticles. In animals treated with Fe nanoparticles (600 µg per mouse), the relaxation time substantially decreased in the liver (3418 ± 1534 µs (control) versus 228 ± 67 µs), the spleen (2170 ± 728 µs versus 299 ± 97 µs), and the lungs (663 ± 101 µs versus 413 ± 99 µs). The change in transverse relaxation was dependent on the number and composition of the nanoparticles. By pixel-wise curve fitting, T2 * maps were calculated showing nanoparticle distribution. In conclusion, UTE sequences may be used to assess and quantify nanoparticle distribution in tissues exhibiting ultrafast signal decay in MRI.


Assuntos
Ferro , Nanopartículas , Animais , Modelos Animais de Doenças , Imageamento por Ressonância Magnética/métodos , Camundongos , Camundongos Endogâmicos C57BL
6.
Small ; : e2004615, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33090693

RESUMO

The understanding of living systems and their building blocks relies on the assessment of structure-function relationships at the nanoscale. Although electron microscopy (EM) gives access to ultrastructural imaging with nanometric resolution, the unambiguous localization of specific molecules is challenging. An EM approach capable of localizing biomolecules with respect to the cellular ultrastructure will offer a direct route to the molecular blueprints of biological systems. In an approach departing from conventional correlative imaging, an electron beam may be used as excitation source to generate optical emission with nanometric resolution, that is, cathodoluminescence (CL). Once suitable luminescent labels become available, CL may be harnessed to enable identification of biomolecule labels based on spectral signatures rather than electron density and size. This work presents CL-enabled immunolabeling based on rare-earth element doped nanoparticle-labels allowing specific molecules to be visualized at nanoscale resolution in the context of the cellular ultrastructure. Folic acid decorated nanoparticles exhibiting single particle CL emission are employed to specifically label receptors and identify characteristic receptor clustering on the surface of cancer cells. This demonstration of CL immunotargeting gives access to protein localization in the context of the cellular ultrastructure and paves the way for immunolabeling of multiple proteins in EM.

7.
Nano Lett ; 19(9): 6013-6018, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31373824

RESUMO

The mechanistic understanding of structure-function relationships in biological systems heavily relies on imaging. While fluorescence microscopy allows the study of specific proteins following their labeling with fluorophores, electron microscopy enables holistic ultrastructural analysis based on differences in electron density. To identify specific proteins in electron microscopy, immunogold labeling has become the method of choice. However, the distinction of immunogold-based protein labels from naturally occurring electron dense granules and the identification of several different proteins in the same sample remain challenging. Correlative cathodoluminescence electron microscopy (CCLEM) bioimaging has recently been suggested to provide an attractive alternative based on labels emitting characteristic light. While luminescence excitation by an electron beam enables subdiffraction imaging, structural damage to the sample by high-energy electrons has been identified as a potential obstacle. Here, we investigate the feasibility of various commonly used luminescent labels for CCLEM bioimaging. We demonstrate that organic fluorophores and semiconductor quantum dots suffer from a considerable loss of emission intensity, even when using moderate beam voltages (2 kV) and currents (0.4 nA). Rare-earth element-doped nanocrystals, in particular Y2O3:Tb3+ and YVO4:Bi3+,Eu3+ nanoparticles with green and orange-red emission, respectively, feature remarkably high brightness and stability in the CCLEM bioimaging setting. We further illustrate how these nanocrystals can be readily differentiated from morphologically similar naturally occurring dense granules based on optical emission, making them attractive nanoparticle core materials for molecular labeling and (multi)color CCLEM.


Assuntos
Substâncias Luminescentes/química , Microscopia Eletrônica , Imagem Molecular , Pontos Quânticos/química , Luminescência , Medições Luminescentes , Metais Terras Raras/química , Nanopartículas/química , Difração de Raios X
8.
Analyst ; 144(23): 6850-6857, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31591608

RESUMO

Despite its crucial role, the placenta is the least understood human organ. Recent clinical studies indicate a direct association between placental calcification and maternal and offspring health. This study reveals distinct characteristics of minerals formed during gestational ageing using cutting-edge nano-analytical characterization and paves the way for investigations focused on the identification of potential markers for disease risks in a clinical setting based on atypical placental mineral fingerprints.


Assuntos
Calcificação Fisiológica/fisiologia , Minerais/análise , Placenta/metabolismo , Animais , Gatos , Cães , Feminino , Cavalos , Humanos , Microscopia Eletrônica de Varredura , Minerais/química , Minerais/metabolismo , Placenta/ultraestrutura , Gravidez , Coelhos , Análise Espectral , Tomografia Computadorizada por Raios X
9.
Crit Care ; 19: 239, 2015 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-26025027

RESUMO

This viewpoint summarizes a selection of nanotechnology-based key concepts relevant to critical care medicine. It focuses on novel approaches for a trigger-dependent release of antimicrobial substances from degradable nano-sized carriers, the ultra-sensitive detection of analytes in body fluid samples by plasmonic and fluorescent nanoparticles, and the rapid removal of pathogens from whole blood using magnetic nanoparticles. The concepts presented here could significantly contribute to the prevention, diagnosis and therapy of bacterial infections in future and it is now our turn to bring them from the bench to the bedside.


Assuntos
Anti-Infecciosos/administração & dosagem , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/tratamento farmacológico , Portadores de Fármacos/administração & dosagem , Nanotecnologia/métodos , Animais , Infecções Bacterianas/prevenção & controle , Humanos , Nanotecnologia/tendências
10.
Adv Healthc Mater ; 13(10): e2302950, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38245823

RESUMO

Hip arthroplasty effectively treats advanced osteoarthritis and is therefore entitled as "operation of the 20th century." With demographic shifts, the USA alone is projected to perform up to 850 000 arthroplasties annually by 2030. Many implants now feature a ceramic head, valued for strength and wear resistance. Nonetheless, a fraction, up to 0.03% may fracture during their lifespan, demanding complex removal procedures. To address this, a radiation-free, fluorescence-based image-guided surgical technique is presented. The method uses the inherent fluorescence of ceramic implant materials, demonstrated through chemical and optical analysis of prevalent implant types. Specifically, Biolox delta implants exhibited strong fluorescence around 700 nm with a 74% photoluminescence quantum yield. Emission tails are identified extending into the near-infrared (NIR-I) biological transparency range, forming a vital prerequisite for the label-free visualization of fragments. This ruby-like fluorescence could be attributed to Cr within the zirconia-toughened alumina matrix, enabling the detection of even deep-seated millimeter-sized fragments via camera-assisted techniques. Additionally, fluorescence microscopy allowed detection of µm-sized ceramic particles, enabling debris visualization in synovial fluid as well as histological samples. This label-free optical imaging approach employs readily accessible equipment and can seamlessly transition to clinical settings without significant regulatory barriers, thereby enhancing the safety, efficiency, and minimally invasive nature of fractured ceramic implant removal procedures.


Assuntos
Prótese de Quadril , Cirurgia Assistida por Computador , Fluorescência , Cerâmica , Zircônio
11.
Adv Sci (Weinh) ; 11(29): e2400673, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38775058

RESUMO

Anastomotic leakage (AL) is the leaking of non-sterile gastrointestinal contents into a patient's abdominal cavity. AL is one of the most dreaded complications following gastrointestinal surgery, with mortality rates reaching up to 27%. The current diagnostic methods for anastomotic leaks are limited in sensitivity and specificity. Since the timing of detection directly impacts patient outcomes, developing new, fast, and simple methods for early leak detection is crucial. Here, a naked eye-readable, electronic-free macromolecular network drain fluid sensor is introduced for continuous monitoring and early detection of AL at the patient's bedside. The sensor array comprises three different macromolecular network sensing elements, each tailored for selectivity toward the three major digestive enzymes found in the drainage fluid during a developing AL. Upon digestion of the macromolecular network structure by the respective digestive enzymes, the sensor produces an optical shift discernible to the naked eye. The diagnostic efficacy and clinical applicability of these sensors are demonstrated using clinical samples from 32 patients, yielding a Receiver Operating Characteristic Area Under the Curve (ROC AUC) of 1.0. This work has the potential to significantly contribute to improved patient outcomes through continuous monitoring and early, low-cost, and reliable AL detection.


Assuntos
Fístula Anastomótica , Diagnóstico Precoce , Humanos , Fístula Anastomótica/diagnóstico , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação
12.
Adv Mater ; 36(23): e2310301, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38298130

RESUMO

Female sterilization via fallopian tube ligation is a common procedure; However, after the operation, over 10% of women seek re-fertilization, which is frequently unsuccessful. In addition, there is evidence that fallopian tubes contribute to the spread of endometriotic tissue as they serve as channels for proinflammatory media entering the abdominal cavity via retrograde menstruation. Here, stimuli-degradable hydrogel implants are presented for the functional, biocompatible, and reversible occlusion of fallopian tubes. The hydrogel implants, designed with customized swelling properties, mechanically occlude fallopian tubes in a high-performance manner with burst pressures reaching 255-558 mmHg, exceeding normal abdominal pressures (95 mmHg). Their damage-free removal can be achieved within 30 min using near-visible UV light or a glutathione solution, employing a method akin to standard fallopian tube perfusion diagnostics. Ultrasound-guided implant placement is demonstrated using a clinical hysteroscope in a human-scale uterus model and biocompatibility in a porcine in vivo model. Importantly, the prevention of live sperm as well as endometrial cell passage through blocked fallopian tubes is demonstrated. Overall, a multifunctional system is presented that constitutes a possible means of on-demand, reversible contraception along with the first-ever mechanical approach to abdominal endometriosis prevention and treatment.


Assuntos
Endometriose , Tubas Uterinas , Hidrogéis , Hidrogéis/química , Feminino , Endometriose/patologia , Animais , Humanos , Suínos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia
13.
Front Bioeng Biotechnol ; 12: 1363126, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38532882

RESUMO

Background: Seroma formation is a common postoperative complication. Fibrin-based glues are typically employed in an attempt to seal the cavity. Recently, the first nanoparticle (NP)-based treatment approaches have emerged. Nanoparticle dispersions can be used as tissue glues, capitalizing on a phenomenon known as 'nanobridging'. In this process, macromolecules such as proteins physically adsorb onto the NP surface, leading to macroscopic adhesion. Although significant early seroma reduction has been shown, little is known about long-term efficacy of NPs. The aim of this study was to assess the long-term effects of NPs in reducing seroma formation, and to understand their underlying mechanism. Methods: Seroma was surgically induced bilaterally in 20 Lewis rats. On postoperative day (POD) 7, seromas were aspirated on both sides. In 10 rats, one side was treated with NPs, while the contralateral side received only NP carrier solution. In the other 10 rats, one side was treated with fibrin glue, while the other was left untreated. Seroma fluid, blood and tissue samples were obtained at defined time points. Biochemical, histopathological and immunohistochemical assessments were made. Results: NP-treated sides showed no macroscopically visible seroma formation after application on POD 7, in stark contrast to the fibrin-treated sides, where 60% of the rats had seromas on POD 14, and 50% on POD 21. At the endpoint (POD 42), sides treated with nanoparticles (NPs) exhibited significant macroscopic differences compared to other groups, including the absence of a cavity, and increased fibrous adhesions. Histologically, there were more macrophage groupings and collagen type 1 (COL1) deposits in the superficial capsule on NP-treated sides. Conclusion: NPs not only significantly reduced early manifestations of seroma and demonstrated an anti-inflammatory response, but they also led to increased adhesion formation over the long term, suggesting a decreased risk of seroma recurrence. These findings highlight both the adhesive properties of NPs and their potential for clinical therapy.

14.
Anesthesiology ; 119(4): 901-6, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23867232

RESUMO

BACKGROUND: Sepsis remains a leading cause of death in intensive care units. There is growing evidence that volatile anesthetics have beneficial immunomodulatory effects on complex inflammation-mediated conditions. The authors investigated the effect of volatile anesthetics on the overall survival of mice in a sepsis model of cecal ligation and puncture (CLP). METHODS: Mice (N = 12 per treatment group) were exposed to anesthetic concentrations of desflurane, isoflurane, and sevoflurane either during induction of sepsis or when the mice showed pronounced symptoms of inflammation. Overall survival, as well as organ function and inflammation was compared with the CLP group without intervention. RESULTS: With desflurane and sevoflurane conditioning (1.2 minimal alveolar concentration for 2 h immediately after induction of CLP) overall survival was improved to 58% and 83%, respectively, compared with 17% in the untreated CLP group. Isoflurane did not significantly affect outcome. Application of sevoflurane 24 h after sepsis induction significantly improved overall survival to 66%. CONCLUSIONS: Administration of the volatile anesthetics desflurane and sevoflurane reduced CLP-induced mortality. Anesthesia may be a critical confounder when comparing study data where different anesthesia protocols were used.


Assuntos
Anestésicos Inalatórios/farmacologia , Ceco/lesões , Sepse/mortalidade , Anestésicos Inalatórios/metabolismo , Animais , Desflurano , Modelos Animais de Doenças , Inflamação/complicações , Inflamação/metabolismo , Isoflurano/análogos & derivados , Isoflurano/metabolismo , Isoflurano/farmacologia , Ligadura , Masculino , Éteres Metílicos/metabolismo , Éteres Metílicos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Sepse/complicações , Sepse/metabolismo , Sevoflurano , Ferimentos Perfurantes
15.
ACS Mater Au ; 3(1): 24-27, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36647456

RESUMO

Close collaboration between basic researchers and clinicians is at the root of medical material and technology innovation. However, the distinctly different educational curricula and various boundary conditions put barriers on such interactions. This short perspective describes current challenges and provides subsequent solutions that may help research laboratories to overcome frequent hurdles and maximize interdisciplinary interactions. The involvement of various stakeholders is key to establishing an environment for barrier-free, effective collaboration, overcoming disciplinary boundaries and creating a strong source of inspiration and motivation for biomedical innovations with clinical impact.

16.
Nanoscale ; 15(45): 18139-18155, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37946534

RESUMO

The field of nanomedicine is rapidly evolving, with new materials and formulations being reported almost daily. In this respect, inorganic and inorganic-organic composite nanomaterials have gained significant attention. However, the use of new materials in clinical trials and their final approval as drugs has been hampered by several challenges, one of which is the complex and difficult to control nanomaterial chemistry that takes place within the body. Several reviews have summarized investigations on inorganic nanomaterial stability in model body fluids, cell cultures, and organisms, focusing on their degradation as well as the influence of corona formation. However, in addition to these aspects, various chemical reactions of nanomaterials, including phase transformation and/or the formation of new/secondary nanomaterials, have been reported. In this review, we discuss recent advances in our understanding of biochemical transformations of medically relevant inorganic (composite) nanomaterials in environments related to their applications. We provide a refined terminology for the primary reaction mechanisms involved to bridge the gaps between different disciplines involved in this research. Furthermore, we highlight suitable analytical techniques that can be harnessed to explore the described reactions. Finally, we highlight opportunities to utilize them for diagnostic and therapeutic purposes and discuss current challenges and research priorities.


Assuntos
Nanomedicina , Nanoestruturas , Nanomedicina/métodos , Nanoestruturas/química , Técnicas de Cultura de Células
17.
Mater Horiz ; 10(10): 4059-4082, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37555747

RESUMO

Radiotherapy is a key pillar of solid cancer treatment. Despite a high level of conformal dose deposition, radiotherapy is limited due to co-irradiation of organs at risk and subsequent normal tissue toxicities. Nanotechnology offers an attractive opportunity for increasing the efficacy and safety of cancer radiotherapy. Leveraging the freedom of design and the growing synthetic capabilities of the nanomaterial-community, a variety of engineered nanomaterials have been designed and investigated as radiosensitizers or radioenhancers. While research so far has been primarily focused on gold nanoparticles and other high atomic number materials to increase the absorption cross section of tumor tissue, recent studies are challenging the traditional concept of high-Z nanoparticle radioenhancers and highlight the importance of catalytic activity. This review provides a concise overview on the knowledge of nanoparticle radioenhancement mechanisms and their quantification. It critically discusses potential radioenhancer candidate materials and general design criteria for different radiation therapy modalities, and concludes with research priorities in order to advance the development of nanomaterials, to enhance the efficacy of radiotherapy and to increase at the same time the therapeutic window.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Radiossensibilizantes , Nanopartículas Metálicas/uso terapêutico , Ouro , Radiossensibilizantes/uso terapêutico , Nanotecnologia
18.
ACS Appl Mater Interfaces ; 15(32): 38367-38380, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37549199

RESUMO

Metal-organic frameworks (MOFs) have found increasing applications in the biomedical field due to their unique properties and high modularity. Although the limited stability of MOFs in biological environments is increasingly recognized, analytical techniques have not yet been harnessed to their full potential to assess the biological fate of MOFs. Here, we investigate the environment-dependent biochemical transformations of widely researched nanosized MOFs (nMOFs) under conditions relevant to their medical application. We assess the chemical stability of antimicrobial zinc-based drug delivery nMOFs (Zn-ZIF-8 and Zn-ZIF-8:Ce) and radio-enhancer candidate nMOFs (Hf-DBA, Ti-MIL-125, and TiZr-PCN-415) containing biologically nonessential group IV metal ions. We reveal that even a moderate decrease in pH to values encountered in lysosomes (pH 4.5-5) leads to significant dissolution of ZIF-8 and partial dissolution of Ti-MIL-125, whereas no substantial dissolution was observed for TiZr-PCN-415 and Hf-DBA nMOFs. Exposure to phosphate-rich buffers led to phosphate incorporation in all nMOFs, resulting in amorphization and morphological changes. Interestingly, long-term cell culture studies revealed that nMOF (bio)transformations of, e.g., Ti-MIL-125 were cellular compartment-dependent and that the phosphate content in the nMOF varied significantly between nMOFs localized in lysosomes and those in the cytoplasm. These results illustrate the delicate nature and environment-dependent properties of nMOFs across all stages of their life cycle, including storage, formulation, and application, and the need for in-depth analyses of biotransformations for an improved understanding of structure-function relationships. The findings encourage the considerate choice of suspension buffers for MOFs because these media may lead to significant material alterations prior to application.


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Sistemas de Liberação de Medicamentos , Metais/química , Compostos Orgânicos , Biotransformação
19.
Adv Biol (Weinh) ; 7(7): e2300075, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37178330

RESUMO

Inorganic nanomaterials have gained increasing attention in radiation oncology, owing to their radiation therapy enhancing properties. To accelerate candidate material selection and overcome the disconnect between conventional 2D cell culture and in vivo findings, screening platforms unifying high-throughput with physiologically relevant endpoint analysis based on 3D in vitro models are promising. Here, a 3D tumor spheroid co-culture model based on cancerous and healthy human cells is presented for the concurrent assessment of radio-enhancement efficacy, toxicity, and intratissural biodistribution with full ultrastructural context of radioenhancer candidate materials. Its potential for rapid candidate materials screening is showcased based on the example of nano-sized metal-organic frameworks (nMOFs) and direct benchmarking against gold nanoparticles (the current "gold standard"). Dose enhancement factors (DEFs) ranging between 1.4 and 1.8 are measured for Hf-, Ti-, TiZr-, and Au-based materials in 3D tissues and are overall lower than in 2D cell cultures, where DEF values exceeding 2 are found. In summary, the presented co-cultured tumor spheroid-healthy fibroblast model with tissue-like characteristics may serve as high-throughput platform enabling rapid, cell line-specific endpoint analysis for therapeutic efficacy and toxicity assessment, as well as accelerated radio-enhancer candidate screening.


Assuntos
Nanopartículas Metálicas , Estruturas Metalorgânicas , Neoplasias , Humanos , Técnicas de Cocultura , Estruturas Metalorgânicas/farmacologia , Estruturas Metalorgânicas/uso terapêutico , Ouro/toxicidade , Ouro/uso terapêutico , Distribuição Tecidual , Esferoides Celulares , Nanopartículas Metálicas/toxicidade , Neoplasias/radioterapia
20.
Biomater Sci ; 11(24): 7826-7837, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37878039

RESUMO

Radiotherapy is a cornerstone of cancer treatment. However, due to the low tissue specificity of ionizing radiation, damage to the surrounding healthy tissue of the tumor remains a significant challenge. In recent years, radio-enhancers based on inorganic nanomaterials have gained considerable interest. Beyond the widely explored metal and metal oxide nanoparticles, 2D materials, such as MXenes, could present potential benefits because of their inherently large specific surface area. In this study, we highlight the promising radio-enhancement properties of Ti3C2Tx MXenes. We demonstrate that atomically thin layers of titanium carbides (Ti3C2Tx MXenes) are efficiently internalized and well-tolerated by mammalian cells. Contrary to MXenes suspended in aqueous buffers, which fully oxidize within days, yielding rice-grain shaped rutile nanoparticles, the MXenes internalized by cells oxidize at a slower rate. This is consistent with cell-free experiments that have shown slower oxidation rates in cell media and lysosomal buffers compared to dispersants without antioxidants. Importantly, the MXenes exhibit robust radio-enhancement properties, with dose enhancement factors reaching up to 2.5 in human soft tissue sarcoma cells, while showing no toxicity to healthy human fibroblasts. When compared to oxidized MXenes and commercial titanium dioxide nanoparticles, the intact 2D titanium carbide flakes display superior radio-enhancement properties. In summary, our findings offer evidence for the potent radio-enhancement capabilities of Ti3C2Tx MXenes, marking them as a promising candidate for enhancing radiotherapy.


Assuntos
Nanopartículas Metálicas , Sarcoma , Humanos , Animais , Raios X , Titânio/farmacologia , Sarcoma/radioterapia , Antioxidantes , Óxidos , Mamíferos
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