Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 240
Filtrar
1.
Nano Lett ; 21(22): 9551-9559, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34738816

RESUMO

Hollow mesoporous organosilica nanoparticles (HMONs) are widely considered as a promising drug nanocarrier, but the loaded drugs can easily leak from HMONs, resulting in the considerably decreased drug loading capacity and increased biosafety risk. This study reports the smart use of core/shell Fe3O4/Gd2O3 (FG) hybrid nanoparticles as a gatekeeper to block the pores of HMONs, which can yield an unreported large loading content (up to 20.4%) of DOX. The conjugation of RGD dimer (R2) onto the DOX-loaded HMON with FG capping (D@HMON@FG@R2) allowed for active tumor-targeted delivery. The aggregated FG in D@HMON@FG@R2 could darken the normal tissue surrounding the tumor due to the high r2 value (253.7 mM-1 s-1) and high r2/r1 ratio (19.13), and the intratumorally released FG as a result of reducibility-triggered HMON degradation could brighten the tumor because of the high r1 value (20.1 mM-1 s-1) and low r2/r1 ratio (7.01), which contributed to high contrast magnetic resonance imaging (MRI) for guiding highly efficient tumor-specific DOX release and chemotherapy.

2.
Transl Oncol ; 15(1): 101264, 2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34781185

RESUMO

Magnetic nanoparticles (MNPs) have been extensively researched and implemented in biomedicine for more than half a century due to their non-invasive nature, ease of temporal and spatial manipulation, and considerable biocompatibility. However, the complex magnetic behaviour of MNPs is influenced by several parameters (e.g., particle size, shape, composition, core-shell structure, etc.), among which the amount of transition metal doping plays an important factor. For this reason, the doping of ferrite with transition metals has been used as an effective strategy to precisely tailor MNPs to achieve satisfactory performance in biomedical applications. In this review, we first introduced the main properties of coordinated MNPs (including magnetic moment and saturated magnetisation) and provide a comprehensive overview of the mechanistic studies related to the doping of transition metal ions into ferrite to precisely modulate its magnetic properties. We also highlighted the potential mechanisms and recent advances in transition metal ion-doped MNPs (TMNPs) for bioimaging (magnetic resonance imaging and magnetic particle imaging) and tumour therapy (e.g., magneto-mechanical killing, magnetothermal therapy, and drug delivery). Finally, we summarised the current challenges and future trends of TMNPs in the biomedical field based on the latest advances by researchers.

3.
Chem Commun (Camb) ; 57(93): 12417-12435, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34734601

RESUMO

Covalent organic frameworks (COFs), as a new type of crystalline porous materials, mainly consist of light-weight elements (H, B, C, N and O) linked by dynamic covalent bonds to form periodical structures of two or three dimensions. As an attribute of their low density, large surface area, and excellent adjustable pore size, COFs show great potential in many fields including energy storage and separation, catalysis, sensing, and biomedicine. However, compared with metal organic frameworks (MOFs), the relatively large size and irregular morphology of COFs affect their biocompatibility and bioavailability in vivo, thus impeding their further biomedical applications. This Review focuses on the controlled design strategies of nanoscale COFs (NCOFs), unique properties of NCOFs for biomedical applications, and recent progress in NCOFs for cancer therapy. In addition, current challenges for the biomedical use of NCOFs and perspectives for further improvements are presented.

4.
Artigo em Inglês | MEDLINE | ID: mdl-34780685

RESUMO

Chemodynamic therapy (CDT), deemed as a cutting-edge antineoplastic therapeutic tactics, efficaciously suppresses tumors via catalytically yielding hydroxyl radicals (•OH) in tumor regions. Nevertheless, its biomedical applications are often restricted by the limited hydrogen peroxide (H2O2) level and upregulated antioxidant defense. Herein, a versatile nanoreactor is elaborately designed via integrating Cu2-xS and MnO2 for T1-weighted magnetic resonance (MR) imaging-guided CDT, synergistically enhanced through hypothermal ablation and oxidation resistance reduction, thereby displaying splendid antitumor efficiency as well as suppression on pulmonary metastasis. The as-synthesized Cu2-xS@MnO2 nanoreactors afford acid-dependent Cu-based and glutathione (GSH)-activated Mn-based catalytic properties for bimodal CDT. Owing to excellent absorbance at the second near-infrared (NIR-II) window, the Cu2-xS furnishes hypo-photo-thermal therapy (PTT) against tumor growth and ameliorates the catalytic performance for thermal-enhanced CDT. Additionally, MnO2 significantly downregulates GSH and glutathione peroxidase 4, which synergistically boosts CDT via promoting oxidative stress, simultaneously generating Mn2+ for MR contrast improvement and activatable tumor imaging. Therefore, this study proffers a new attempt centered on the collaborative strategy integrating NIR-II hypothermal PTT and synergistically enhanced CDT for tumor eradication.

5.
J Phys Chem Lett ; : 11280-11287, 2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34767373

RESUMO

Zeolitic imidazolate frameworks (ZIFs), widely regarded as promising materials for application in catalysis and separation, hold an increasingly significant position in drug delivery systems for their high drug loading capacity. Focused specifically on the rational design of targeting and bioresponsive nanovehicles, a neuropeptide Y1 receptor ligand (Y1L)-modified cell membrane camouflaged bioresponsive ZIF system (Y1L-RBC@ZIF-90@Ce6) was constructed for targeted photodynamic therapy of breast cancer. The biomimetic ZIF-based nanocarrier enhanced tumor accumulation by both neuropeptide Y1 receptor-targeted guidance and long-term stability. Y1L served as a good ligand-mediated selective targeting molecule for breast cancer, and red blood cell membrane-camouflaged nanocomposites displayed favorable biocompatibility. With the dual response of the ZIF to pH and adenosine triphosphate, the stimulus responsive photosensitizer Chlorin e6 delivery system effectively suppressed tumors in vivo. This work offers a platform for developing much safer and more efficient photodynamic therapy for the treatment of Y1R-overexpressed breast cancer.

6.
Nanoscale ; 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34761764

RESUMO

Polypyrrole (PPy) nanoparticles have been widely studied in tumor photothermal therapy (PTT) for their significant photostability, good biocompatibility, and excellent photothermal performance. Herein, we report bovine serum albumin (BSA) stabilized PPy that were mineralized by MnO2 nanozyme on the surface (PPy@BSA-MnO2) to achieve synergistic photothermal and chemodynamic therapy (CDT) for breast cancer. In this multifunctional nanoplatform, the surface-loaded MnO2 undergoes a redox reaction with glutathione (GSH) to generate glutathione disulfide (GSSG) and Mn2+. Then, Mn2+ can convert H2O2 into a highly cytotoxic ˙OH to achieve chemodynamic therapy (CDT) and possess good magnetic resonance (MR) T1-weighted imaging capabilities to realize contrast imaging of the 4T1 tumor-bearing mouse models. In addition, PPy nanoparticles can efficiently convert near-infrared light energy into heat and achieve PTT. Most importantly, PPy@BSA-MnO2 nanoprobes have excellent in vitro 4T1 cell-killing effect and in vivo tumor-suppressive properties. The acute toxicity assessment results indicate that PPy@BSA-MnO2 nanoprobes have good biological safety. Therefore, the as-prepared multifunctional PPy@BSA-MnO2 nanoprobes possess excellent performance to promote MRI-guided PTT/CDT synergistic therapy for breast cancer treatment and have extensive clinical transformation and application prospects.

7.
J Nanobiotechnology ; 19(1): 299, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34592992

RESUMO

Long-lasting moisture retention is a huge challenge to humectants, and effective methods or additives for promote these functions are limited, especially nano-additives. Carbon dots (CDs) have attracted increasing research interest due to its ultra-small size, excellent optical properties and low toxicity, etc. However, most of researches have been focused on the photoexcited CDs and its subsequent photophysical and chemical processes, such as photoluminescence, photodynamic, photothermal and photocatalytic behavior. The intrinsic chemo-physical properties of the pristine CDs are not fully explored. Here, we report an excellent moisture retention capability of a new carmine cochineal-derived CDs (Car-CDs) for the first time. The relationship between the structure of Car-CDs and its moisture retention capability is revealed. More interestingly, the effective applications of Car-CDs in moisturizing lipstick are demonstrated. This work expands the research and application of CDs into a broad, new area, potentially in skin care.

8.
Pathogens ; 10(10)2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34684215

RESUMO

This study utilized modeling and simulation to examine the effectiveness of current and potential future COVID-19 response interventions in the West African countries of Guinea, Liberia, and Sierra Leone. A comparison between simulations can highlight which interventions could have an effect on the pandemic in these countries. An extended compartmental model was used to run simulations incorporating multiple vaccination strategies and non-pharmaceutical interventions (NPIs). In addition to the customary categories of susceptible, exposed, infected, and recovered (SEIR) compartments, this COVID-19 model incorporated early and late disease states, isolation, treatment, and death. Lessons learned from the 2014-2016 Ebola virus disease outbreak-especially the optimization of each country's resource allocation-were incorporated in the presented models. For each country, models were calibrated to an estimated number of infections based on actual reported cases and deaths. Simulations were run to test the potential future effects of vaccination and NPIs. Multiple levels of vaccination were considered, based on announced vaccine allocation plans and notional scenarios. Increased vaccination combined with NPI mitigation strategies resulted in thousands of fewer COVID-19 infections in each country. This study demonstrates the importance of increased vaccinations. The levels of vaccination in this study would require substantial increases in vaccination supplies obtained through national purchases or international aid. While this study does not aim to develop a model that predicts the future, it can provide useful information for decision-makers in low- and middle-income nations. Such information can be used to prioritize and optimize limited available resources for targeted interventions that will have the greatest impact on COVID-19 pandemic response.

9.
Pathogens ; 10(10)2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34684297

RESUMO

Epidemiological modeling and simulation can contribute cooperatively across multifaceted areas of biosurveillance systems. These efforts can be used to support real-time decision-making during public health emergencies and response operations. Robust epidemiological modeling and simulation tools are crucial to informing risk assessment, risk management, and other biosurveillance processes. The Defense Threat Reduction Agency (DTRA) has sponsored the development of numerous modeling and decision support tools to address questions of operational relevance in response to emerging epidemics and pandemics. These tools were used during the ongoing COVID-19 pandemic and the Ebola outbreaks in West Africa and the Democratic Republic of the Congo. This perspective discusses examples of the considerations DTRA has made when employing epidemiological modeling to inform on public health crises and highlights some of the key lessons learned. Future considerations for researchers developing epidemiological modeling tools to support biosurveillance and public health operations are recommended.

10.
Biomater Sci ; 9(22): 7591-7602, 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34668000

RESUMO

Photothermal therapy (PTT), as a promising antineoplastic therapeutic strategy, has been harnessed to restrain tumor growth through near-infrared (NIR) irradiation mediated thermal ablation. Nevertheless, its biological applications are hampered by thermal diffusion and up-regulated heat shock proteins (HSPs). Herein, a versatile nanotheranostic agent is developed via integrating Zn0.2Fe2.8O4 nanoparticles (NPs), polydopamine (PDA), and MnO2 NPs for T1/T2 dual-modal magnetic resonance (MR) imaging-guided and self-augmented PTT. The as-designed Zn0.2Fe2.8O4@PDA@MnO2 NPs adequately serve as a PTT agent to realize effective photothermal conversion and obtain local hyperthermia. Additionally, the Zn0.2Fe2.8O4@PDA@MnO2 NPs can significantly consume overexpressed glutathione (GSH) and generate Mn2+ in the tumor microenvironment (TME), thus destroying redox homeostasis and catalytically generating hydroxyl radicals (˙OH) for HSP suppression and PTT enhancement. Meanwhile, Mn2+ and Zn0.2Fe2.8O4 NPs significantly strengthen T1- and T2-weighted MR contrast for tumor imaging and PTT guidance. Hence, this study offers proof of concept for self-augmented PTT and T1/T2 dual-modal MR imaging for tumor elimination.


Assuntos
Hipertermia Induzida , Nanopartículas , Imageamento por Ressonância Magnética , Compostos de Manganês , Óxidos , Terapia Fototérmica , Nanomedicina Teranóstica , Microambiente Tumoral
11.
ACS Nano ; 15(9): 15069-15084, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34420298

RESUMO

The existence of cancer stem cells (CSCs) poses a major obstacle for the success of current cancer therapies, especially the fact that non-CSCs can spontaneously turn into CSCs, which lead to the failure of the treatment and tumor relapse. Therefore, it is very important to develop effective strategies for the eradication of the CSCs. In this work, we have developed a CSCs-specific targeted, retinoic acid (RA)-loaded gold nanostars-dendritic polyglycerol (GNSs-dPG) nanoplatform for the efficient eradication of CSCs. The nanocomposites possess good biocompatibility and exhibit effective CSCs-specific multivalent targeted capability due to hyaluronic acid (HA) decorated on the multiple attachment sites of the bioinert dendritic polyglycerol (dPG). With the help of CSCs differentiation induced by RA, the self-renewal of breast CSCs and tumor growth were suppressed by the high therapeutic efficacy of photothermal therapy (PTT) in a synergistic inhibitory manner. Moreover, the stemness gene expression and CSC-driven tumorsphere formation were significantly diminished. In addition, the in vivo tumor growth and CSCs were also effectively eliminated, which indicated superior anticancer activity, effective CSCs suppression, and prevention of relapse. Taken together, we developed a CSCs-specific targeted, RA-loaded GNSs-dPG nanoplatform for the targeted eradication of CSCs and for preventing the relapse.


Assuntos
Ouro , Neoplasias , Glicerol , Células-Tronco Neoplásicas , Terapia Fototérmica , Polímeros , Tretinoína/farmacologia
12.
J Mater Chem B ; 9(33): 6623-6633, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34378616

RESUMO

Cancer treatment has been recently energized by nanomaterials that simultaneously offer diagnostic and therapeutic effects. Among the imaging and treatment modalities in frontline research today, magnetic resonance imaging (MRI) and phototherapy have gained significant interest due to their noninvasiveness among other intriguing benefits. Herein, Fe(iii) was adsorbed on titanium dioxide to develop magnetic Fe-TiO2 nanocomposites (NCs) which leverage the Fe moiety in a double-edge-sword approach to: (i) achieve T1-weighted MRI contrast enhancement, and (ii) improve the well-established photodynamic therapeutic efficacy of TiO2 nanoparticles. Interestingly, the proposed NCs exhibit classic T1 MRI contrast agent properties (r1 = 1.16 mM-1 s-1) that are comparable to those of clinically available contrast agents. Moreover, the NCs induce negligible cytotoxicity in traditional methods and show remarkable support to the proliferation of intestine organoids, an advanced toxicity evaluation system based on three-dimensional organoids, which could benefit their potential safe application for in vivo cancer theranostics. Aided by the Fenton reaction contribution of the Fe component of the Fe-TiO2 NCs, considerable photo-killing of cancer cells is achieved upon UV irradiation at very low (2.5 mW cm-2) intensity in typical cancer PDT. It is therefore expected that this study will guide the engineering of other biocompatible magnetic titania-based nanosystems with multi-faceted properties for biomedical applications.

13.
Adv Mater ; 33(37): e2102054, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34309925

RESUMO

Arsenical drugs have achieved hallmark success in treating patients with acute promyelocytic leukemia, but expanding their clinical utility to solid tumors has proven difficult with the contradiction between the therapeutic efficacy and the systemic toxicity. Here, leveraging efforts from materials science, biocompatible PEGylated arsenene nanodots (AsNDs@PEG) with high monoelemental arsenic purity that can selectively and effectively treat solid tumors are synthesized. The intrinsic selective killing effect of AsNDs@PEG is closely related to high oxidative stress in tumor cells, which leads to an activated valence-change of arsenic (from less toxic As0 to severely toxic oxidation states), followed by decreased superoxide dismutase activity and massive reactive oxygen species (ROS) production. These effects occur selectively within cancer cells, causing mitochondrial damage, cell-cycle arrest, and DNA damage. Moreover, AsNDs@PEG when applied in a multi-drug combination strategy with ß-elemene, a plant-derived anticancer drug, achieves synergistic antitumor outcomes, and its newly discovered on-demand photothermal properties facilitate the elimination of the tumors without recurrence, potentially further expanding its clinical utility. In line of the practicability for a large-scale fabrication and negligible systemic toxicity of AsNDs@PEG (even at high doses and with repetitive administration), a new-concept arsenical drug with high therapeutic efficacy for selective solid tumor therapy is provided.

14.
Sci China Life Sci ; 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34258713

RESUMO

The detection of circulating tumor cells (CTCs) is a crucial tool for early cancer diagnosis, prognosis, and postoperative evaluation. However, detection sensitivity remains a major challenge because CTCs are extremely rare in peripheral blood. To effectively detect CTCs, octahedral Ag2O nanoparticles (NPs) with high dispersibility, good biocompatibility, remarkable surface-enhanced Raman scattering (SERS) enhancement, and obvious enhancement selectivity are designed as an SERS platform. Ag2O NPs with many oxygen vacancy defects are successfully synthesized, which exhibit an ultra-high SERS enhancement factor (1.98×106) for 4-mercaptopyridine molecules. The remarkable SERS activity of octahedral Ag2O NPs is derived from the synergistic effect of the surface defect-promoted photo-induced charge transfer (PICT) process and strong vibration coupling resonance in the Ag2O-molecule SERS complex, greatly amplifying the molecular Raman scattering cross-section. The promoted PICT process is confirmed using ultraviolet-visible (UV-Vis) absorption spectroscopy, demonstrating that obvious PICT resonance occurs in Ag2O SERS system under visible light. An additional growth step of SERS bioprobe is proposed by modifying the Raman signal molecules and functional biological molecules on Ag2O NPs for CTC detection. The Ag2O-based SERS bioprobe exhibits excellent detection specificity for different cancer cells in rabbit blood. Importantly, the high-sensitivity Ag2O-based SERS bioprobe satisfies the requirement for rare CTC detection in the peripheral blood of cancer patients, and the detection limit can reach 1 cell per mL. To our knowledge, this study is the first time that a semiconductor SERS substrate has been successfully utilized in CTC detection. This work provides new insights into CTC detection and the development of novel semiconductor-based SERS platforms for cancer diagnosis.

15.
Cancers (Basel) ; 13(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34298600

RESUMO

Triple-negative breast cancer (TNBC) is highly recurring and metastatic breast cancer with overexpressing epidermal growth factor receptor (EGFR). Herein, a series of in vitro and in vivo analyses were used to explore the therapeutic effect of EGFR-targeting nano-micelles (PLGA-PEG/DOX@anti-EGFR) combined with ultrasound-mediated cavitation (UMC). The prepared nano-micelle drug carriers have good biocompatibility and can greatly increase the drug accumulation in tumor regions, thereby reducing off-target toxicity while enhancing anti-tumor efficacy. Moreover, an in vivo analysis of the practical utility of this treatment modality was conducted by using SonoVueTM microbubbles to achieve cavitation under different power intensity levels, with an ultrasonic power intensity of 0.5 W/cm2 maximizing the intra-tumoral blood perfusion. Relative to PLGA-PEG@DOX/anti-EGFR nano-micelles treatment alone, the combination with UMC was better able to suppress tumor growth even at low concentrations. As such, combining actively targeted drug-carrier molecules with UMC represents an effective approach to enhancing therapeutic efficacy while reducing the adverse, systemic effects associated with DOX and other chemotherapeutic drugs, and it can be considered as a promising clinical prospect in the treatment of TNBC.

16.
J Environ Sci (China) ; 104: 351-364, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33985738

RESUMO

Cadmium contamination of soil is a global issue and in-situ remediation technology as a promising mitigation strategy has attracted more and more attention. Many nanomaterials have been applied for the in-situ remediation of cadmium-contaminated soil due to their excellent properties of the nano-scale size effect. In this work, recent research progress of various nanomaterials, including carbon nanomaterials, metal-based nanomaterials and nano mineral materials, in the removal of cadmium and in-situ remediation of cadmium-contaminated soil were systematically discussed. Additional emphases were particularly laid on both laboratory and field restoration effects. Moreover, the factors which can affect the stability of cadmium, main interaction mechanisms between nanomaterials and cadmium in the soil, and potential future research direction were also provided. Therefore, it is believed that this work will ultimately contribute to the myriad of environmental cleanup advances, and further improve human health and sustainable development.


Assuntos
Recuperação e Remediação Ambiental , Nanoestruturas , Poluentes do Solo , Cádmio/análise , Humanos , Solo , Poluentes do Solo/análise
17.
Nanoscale ; 13(13): 6461-6474, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33885526

RESUMO

Unlike stable atherosclerotic plaques, vulnerable plaques are very likely to cause serious cardio-cerebrovascular diseases. Meanwhile, how to non-invasively identify vulnerable plaques at early stages has been an urgent but challenging problem in clinical practices. Here, we propose a macrophage-targeted and in situ stimuli-triggered T1-T2 switchable magnetic resonance imaging (MRI) nanoprobe for the non-invasive diagnosis of vulnerable plaques. Precisely, single-dispersed iron oxide nanoparticles (IONPs) modified with hyaluronic acid (HA), denoted as IONP-HP, show macrophage targetability and T1 MRI enhancement (r2/r1 = 3.415). Triggered by the low pH environment of macrophage lysosomes, the single-dispersed IONP-HP transforms into a cluster analogue, which exhibits T2 MRI enhancement (r2/r1 = 13.326). Furthermore, an in vivo switch of T1-T2 enhancement modes shows that the vulnerable plaques exhibit strong T1 enhancement after intravenous administration of the nanoprobe, followed by a switch to T2 enhancement after 9 h. In contrast, stable plaques show only slight T1 enhancement but without T2 enhancement. It is therefore imperative that the intelligent and novel nanoplatform proposed in this study achieves a substantial non-invasive diagnosis of vulnerable plaques by means of a facile but effective T1-T2 switchable process, which will significantly contribute to the application of materials science in solving clinical problems.


Assuntos
Meios de Contraste , Placa Aterosclerótica , Humanos , Imageamento por Ressonância Magnética , Placa Amiloide , Placa Aterosclerótica/diagnóstico por imagem
18.
Micromachines (Basel) ; 12(4)2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33918189

RESUMO

Separation and detection are ubiquitous in our daily life and they are two of the most important steps toward practical biomedical diagnostics and industrial applications. A deep understanding of working principles and examples of separation and detection enables a plethora of applications from blood test and air/water quality monitoring to food safety and biosecurity; none of which are irrelevant to public health. Microfluidics can separate and detect various particles/aerosols as well as cells/viruses in a cost-effective and easy-to-operate manner. There are a number of papers reviewing microfluidic separation and detection, but to the best of our knowledge, the two topics are normally reviewed separately. In fact, these two themes are closely related with each other from the perspectives of public health: understanding separation or sorting technique will lead to the development of new detection methods, thereby providing new paths to guide the separation routes. Therefore, the purpose of this review paper is two-fold: reporting the latest developments in the application of microfluidics for separation and outlining the emerging research in microfluidic detection. The dominating microfluidics-based passive separation methods and detection methods are discussed, along with the future perspectives and challenges being discussed. Our work inspires novel development of separation and detection methods for the benefits of public health.

19.
Nano Lett ; 21(7): 2730-2737, 2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33797257

RESUMO

Recently, magnetic particle imaging (MPI) has shown diverse biomedical applications such as cell tracking, lung perfusion, image-guided hyperthermia, and so forth. However, the currently reported MPI agents cannot achieve the possible theoretical detection limit of MPI (20 nM). A previous theoretical study has shown that the MPI performance of superparamagnetic iron oxide nanoparticles (SPIONs) can be enhanced by carbon supporting and metal doping. In the current study, a series of mixed metal metal-organic framework-derived carbon supporting SPIONs were synthesized by pyrolysis. Among the synthesized SPIONs, the MPI signal intensity of ZnFe2O4/C@PDA was found to be 4.7 times higher than the commercial MPI contrast (Vivotrax) having the same Fe concentration. ZnFe2O4/C@PDA also showed the highest MPI intensity in tumor-bearing-mice among all tested samples. Furthermore, they were found highly biocompatible and showed linear cell quantification. This work can open new avenues for the design and development of novel and high-performance MPI agents.

20.
ACS Appl Mater Interfaces ; 13(13): 14928-14937, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33759491

RESUMO

In order to achieve safe and high-efficient photodynamic therapy (PDT), it was a powerful strategy of constructing O2-generated nanozyme with intelligent "off/on" modulation and enhancement. Herein, a kind of H2O2-responsive nanozyme was developed for off/on modulation and enhancement of magnetic resonance (MR) imaging and PDT, in which great amounts of gold nanoclusters (AuNCs) were loaded into mesoporous silica to form nanoassembly, and manganese dioxide (MnO2) nanosheets were wrapped as switching shield shell (AuNCs@mSiO2@MnO2). In a neutral physiological environment, stable MnO2 shells eliminated singlet oxygen (1O2) generation to switch off PDT and MR imaging. However, in an acidic tumor microenvironment, the MnO2 shell reacted with H2O2, in which MnO2 degradation switched on MR imaging and PDT, and the generated O2 further enhanced PDT. H2O2-responsive MnO2 degradation brought about excellent MR imaging with a longitudinal relaxation rate of 25.31 mM-1 s-1, and simultaneously sufficient O2 generation guaranteed a 74% high 1O2 yield. Under the irradiation of a 635 nm laser, the viability of MDA-MB-435 cells was reduced to 4%, and the tumors completely disappeared, demonstrating strong PDT performance. Therefore, H2O2-responsive AuNCs@mSiO2@MnO2 nanozyme showed excellent off/on modulation and enhancement of MR imaging and PDT and was a promising intelligent nanoprobe for safe and high-efficiency theranostics.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/tratamento farmacológico , Ouro/uso terapêutico , Compostos de Manganês/uso terapêutico , Nanopartículas/uso terapêutico , Óxidos/uso terapêutico , Fármacos Fotossensibilizantes/uso terapêutico , Animais , Linhagem Celular Tumoral , Feminino , Ouro/química , Humanos , Peróxido de Hidrogênio/metabolismo , Imageamento por Ressonância Magnética , Compostos de Manganês/química , Camundongos , Camundongos Nus , Nanopartículas/química , Óxidos/química , Fotoquimioterapia , Fármacos Fotossensibilizantes/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...