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1.
ACS Appl Mater Interfaces ; 16(5): 6208-6220, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38279946

RESUMEN

Quantum dots (QDs) are colloidal semiconductor nanoparticles acting as fluorescent probes for detection, disease diagnosis, and photothermal and photodynamic therapy. However, their performance in cancer treatment is limited by inadequate tumor accumulation and penetration due to the larger size of nanoparticles compared to small molecules. To address this challenge, charge reversal nanoparticles offer an effective strategy to prolong blood circulation time and achieve enhanced endocytosis and tumor penetration. In this study, we leveraged the overexpressed γ-glutamyl transpeptidase (GGT) in many human tumors and developed a library of modular peptides to serve as water-soluble surface ligands of QDs. We successfully transferred the QDs from the organic phase to the aqueous phase within 5 min. And through systematic tuning of the peptide sequence, we optimized the fluorescent stability of QDs and their charge reversal behavior in response to GGT. The resulting optimal peptide stabilized QDs in aqueous solution with a high fluorescent retention rate of 93% after three months and realized the surface charge reversal of QDs triggered by GGT in vitro. The binding between the peptide and QD surface was investigated by using saturation transfer differential nuclear magnetic resonance (STD NMR). Thanks to its charge reversal ability, the GGT-responsive QDs exhibited enhanced cellular uptake in GGT-expressing cancer cells and deeper penetration in the 3D multicellular spheroids. This enzyme-responsive modular peptide can lead to specific tumor targeting and deeper tumor penetration, holding great promise to enhance the treatment efficacy of QD-based theranostics.


Asunto(s)
Nanopartículas , Neoplasias , Puntos Cuánticos , Humanos , Puntos Cuánticos/química , Péptidos/química , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Secuencia de Aminoácidos
2.
Neuroscience ; 537: 21-31, 2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-38040086

RESUMEN

BACKGROUND AND PURPOSE: Apoptosis is involved in the occurrence and development of acute ischemic stroke (AIS). This study aimed to assess whether Chuanzhitongluo (CZTL), a multi-target and multi-pathway compound preparation, plays a neuroprotective role in AIS by modulating neuronal apoptosis via the PI3K/AKT signaling pathway. METHODS: A mouse model of AIS was established by photochemical processes. Cerebral infarction volume was measured by 2% staining with 2, 3, and 5-triphenyl tetrazole chloride (TTC). Neuron apoptosis was assessed by TUNEL staining. Apoptosis RNA arrays were used to detect changes in apoptosis-related gene expression profiles. Western blotting was used to detect proteins involved in the PI3K/AKT signaling pathway. RESULTS: The study demonstrated that CZTL could potentially mitigate neuronal apoptosis in AIS mice. This appears to be achieved via the up-regulation of certain genes such as BCL-2, Birc6, and others, coupled with the down-regulation of genes like BAX, Bid, and Casp3. Further validation revealed that CZTL could enhance the expression of BCL-2 and reduce the expression of Cleaved Caspase-3 and BAX at both the gene and protein levels. The study also found that CZTL can enhance the phosphorylation level of the PI3K/AKT signaling pathway. In contrast to these findings, the PI3K inhibitor LY294002 notably amplified neuronal apoptosis in AIS mice. CONCLUSIONS: These findings imply that CZTL's ability to inhibit neuronal apoptosis may be linked to the activation of AIS's PI3K/AKT signaling pathway.


Asunto(s)
Accidente Cerebrovascular Isquémico , Proteínas Proto-Oncogénicas c-akt , Ratas , Animales , Ratones , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteína X Asociada a bcl-2/metabolismo , Ratas Sprague-Dawley , Transducción de Señal , Apoptosis , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo
3.
Nanoscale ; 15(33): 13603-13616, 2023 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-37555299

RESUMEN

Advanced nanoplatforms equipped with different functional moieties for theranostics hold appealing promise for reshaping precision medicine. The reliable construction of an individual nanomaterial with intrinsic near-infrared (NIR) photofunction and magnetic domains is much desired but largely unexplored in a direct aqueous synthesis system. Herein, we develop an aqueous phase synthetic strategy for Mn2+ doping of ZnS shell grown on Zn-Cu-In-Se core quantum dots (ZCISe@ZnS:Mn QDs), providing the optimal NIR fluorescence quantum efficiency of up to 18.9% and meanwhile efficiently introducing paramagnetic domains. The relaxometric properties of the water-soluble Mn-doped QDs make them desirable for both the longitudinal and transverse (T1 and T2) magnetic resonance (MR) contrast enhancement due to the shell lattice-doped Mn2+ ions with slow tumbling rates and favoured spin-proton dipolar interactions with surrounding water molecules. Surprisingly, the incorporation of Mn2+ ions into the shell is found to significantly enhance the production of reactive oxygen species (ROS) by combining both the chemodynamic and photodynamic processes upon NIR light irradiation, showing great potential for efficient photo-assisted ablation of cancer cells. Furthermore, a broad-spectrum excitation range beneficial for bright NIR fluorescence imaging of breast cancer has been proven and offers high flexibility in the choice of incident light sources. Multiparametric MR imaging of the brain has also been successfully demonstrated in vivo.


Asunto(s)
Puntos Cuánticos , Humanos , Cobre , Indio , Agua
4.
ACS Nano ; 17(12): 11290-11308, 2023 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-37276377

RESUMEN

Cancer phototheranostics have the potential for significantly improving the therapeutic effectiveness, as it can accurately diagnose and treat cancer. However, the current phototheranostic platforms leave much to be desired and are often limited by tumor hypoxia. Herein, a Schottky junction nanozyme has been established between a manganese-bridged cobalt-phthalocyanines complex and Ti3C2Tx MXene nanosheets (CoPc-Mn/Ti3C2Tx), which can serve as an integrative type I and II photosensitizer for enhancing cancer therapeutic efficacy via a photoacoustic imaging-guided multimodal chemodynamic/photothermal/photodynamic therapy strategy under near-infrared (808 nm) light irradiation. The Schottky junction not only possessed a narrow-bandgap, enhanced electron-hole separation ability and exhibited a potent redox potential but also enabled improved H2O2 and O2 supplying performances in vitro. Accordingly, the AS1411 aptamer-immobilized CoPc-Mn/Ti3C2Tx nanozyme illustrated high accuracy and excellent anticancer efficiency through a multimodal therapy strategy in in vitro and in vivo experiments. This work presents a valuable method for designing and constructing a multifunctional nanocatalytic medicine platform for synergistic cancer therapy of solid tumors.


Asunto(s)
Nanopartículas , Neoplasias , Fotoquimioterapia , Humanos , Fotoquimioterapia/métodos , Peróxido de Hidrógeno , Titanio/uso terapéutico , Neoplasias/diagnóstico por imagen , Neoplasias/tratamiento farmacológico , Línea Celular Tumoral , Microambiente Tumoral , Nanopartículas/uso terapéutico
5.
J Nanobiotechnology ; 21(1): 4, 2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36597067

RESUMEN

BACKGROUND: Although the promising advancements of current therapeutic approaches is available for the squamous cell carcinoma (SCC) patients, the clinical treatment of SCC still faces many difficulties. The surgical irreparable disfigurement and the postoperative wound infection largely hamper the recovery, and the chemo/radiotherapy leads to toxic side effects. RESULTS: Herein, a novel pH/Hyaluronidase (HAase) dual-stimuli triggered smart nanoprobe FeIIITA@HA has been designed through the biomineralization of Fe3+ and polyphenol tannic acid (TA) under the control of hyaluronic acid (HA) matrix. With the HA residues on the outer surface, FeIIITA@HA nanoprobes can specifically target the SCC cells through the over-expressed CD44, and accumulate in the carcinoma region after intravenously administration. The abundant HAase in carcinoma microenvironment will trigger the degradation of HA molecules, thereby exposing the FeIIITA complex. After ingesting by tumor cells via CD44 mediated endocytosis, the acidic lysosomal condition will further trigger the protonation of TA molecules, finally leading to the Fe3+ release of nanoprobe, and inducing a hybrid ferroptosis/apoptosis of tumor cells through peroxidase activity and glutathione depletion. In addition, Owing to the outstanding T1 magnetic resonance imaging (MRI) performance and phototermal conversion efficiency of nanoprobes, the MRI-guided photothermal therapy (PTT) can be also combined to complement the Fe3+-induced cancer therapy. Meanwhile, it was also found that the nanoprobes can promote the recruitment of CD4+ and CD8+ T cells to inhibit the tumor growth through the cytokines secretion. In addition, the FeIIITA@HA nanoprobes can be eliminated from the body and no obvious adverse side effect can be found in histological analysis, which confirmed the biosafety of them. CONCLUSION: The current FeIIITA@HA nanoprobe has huge potential in clinical translation in the field of precise diagnosis and intelligent synergistic therapy of superficial SCC. This strategy will promisingly avoid the surgical defects, and reduce the systemic side effect of traditional chemotherapy, paving a new way for the future SCC treatment.


Asunto(s)
Carcinoma de Células Escamosas , Nanopartículas , Neoplasias , Humanos , Linfocitos T CD8-positivos , Neoplasias/tratamiento farmacológico , Fototerapia/métodos , Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/tratamiento farmacológico , Línea Celular Tumoral , Nanopartículas/uso terapéutico , Nanopartículas/química , Microambiente Tumoral
6.
Proc Natl Acad Sci U S A ; 119(51): e2211534119, 2022 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-36508653

RESUMEN

Food fortification is an effective strategy to address vitamin A (VitA) deficiency, which is the leading cause of childhood blindness and drastically increases mortality from severe infections. However, VitA food fortification remains challenging due to significant degradation during storage and cooking. We utilized an FDA-approved, thermostable, and pH-responsive basic methacrylate copolymer (BMC) to encapsulate and stabilize VitA in microparticles (MPs). Encapsulation of VitA in VitA-BMC MPs greatly improved stability during simulated cooking conditions and long-term storage. VitA absorption was nine times greater from cooked MPs than from cooked free VitA in rats. In a randomized controlled cross-over study in healthy premenopausal women, VitA was readily released from MPs after consumption and had a similar absorption profile to free VitA. This VitA encapsulation technology will enable global food fortification strategies toward eliminating VitA deficiency.


Asunto(s)
Deficiencia de Vitamina A , Vitamina A , Femenino , Ratas , Animales , Alimentos Fortificados , Estudios Cruzados , Culinaria , Micronutrientes
7.
ACS Nano ; 16(5): 8076-8094, 2022 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-35442624

RESUMEN

Improving the effectiveness of cancer therapy will require tools that enable more specific cancer targeting and improved tumor visualization. Theranostics have the potential for improving cancer care because of their ability to serve as both diagnostics and therapeutics; however, their diagnostic potential is often limited by tissue-associated light absorption and scattering. Herein, we develop CuInSe2@ZnS:Mn quantum dots (QDs) with intrinsic multifunctionality that both enable the accurate localization of small metastases and act as potent tumor ablation agents. By leveraging the growth kinetics of a ZnS shell on a biocompatible CuInSe2 core, Mn doping, and folic acid functionalization, we produce biocompatible QDs with high near-infrared (NIR)-II fluorescence efficiency up to 31.2%, high contrast on magnetic resonance imaging (MRI), and preferential distribution in 4T1 breast cancer tumors. MRI-enabled contrast of these nanoprobes is sufficient to timely identify small metastases in the lungs, which is critically important for preventing cancer spreading and recurrence. Further, exciting tumor-resident QDs with NIR light produces both fluorescence for tumor visualization through radiative recombination pathways as well as heat and radicals through nonradiative recombination pathways that kill cancer cells and initiate an anticancer immune response, which eliminates tumor and prevents tumor regrowth in 80% of mice.


Asunto(s)
Neoplasias , Puntos Cuánticos , Ratones , Animales , Compuestos de Zinc , Neoplasias/patología , Imagen por Resonancia Magnética/métodos
8.
Adv Mater ; 34(21): e2202168, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35362203

RESUMEN

Nanovaccines have emerged as promising alternatives or complements to conventional cancer treatments. Despite the progresses, specific co-delivery of antigen and adjuvant to their corresponding intracellular destinations for maximizing the activation of antitumor immune responses remains a challenge. Herein, a lipid-coated iron oxide nanoparticle is delivered as nanovaccine (IONP-C/O@LP) that can co-deliver peptide antigen and adjuvant (CpG DNA) into cytosol and lysosomes of dendritic cells (DCs) through both membrane fusion and endosome-mediated endocytosis. Such two-pronged cellular uptake pattern enables IONP-C/O@LP to synergistically activate immature DCs. Iron oxide nanoparticle also exhibits adjuvant effects by generating intracellular reactive oxygen species, which further promotes DC maturation. IONP-C/O@LP accumulated in the DCs of draining lymph nodes effectively increases the antigen-specific T cells in both tumor and spleen, inhibits tumor growth, and improves animal survival. Moreover, it is demonstrated that this nanovaccine is a general platform of delivering clinically relevant peptide antigens derived from human papilloma virus 16 to trigger antigen-specific immune responses in vivo.


Asunto(s)
Nanopartículas , Neoplasias , Adyuvantes Inmunológicos/farmacología , Animales , Antígenos , Células Dendríticas , Inmunoterapia , Ratones , Ratones Endogámicos C57BL , Neoplasias/terapia , Péptidos
9.
Innovation (Camb) ; 2(4): 100174, 2021 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-34766099

RESUMEN

A vast majority of cancer deaths occur as a result of metastasis. Unfortunately, effective treatments for metastases are currently lacking due to the difficulty of selectively targeting these small, delocalized tumors distributed across a variety of organs. However, nanotechnology holds tremendous promise for improving immunotherapeutic outcomes in patients with metastatic cancer. In contrast to conventional cancer immunotherapies, rationally designed nanomaterials can trigger specific tumoricidal effects, thereby improving immune cell access to major sites of metastasis such as bone, lungs, and lymph nodes, optimizing antigen presentation, and inducing a persistent immune response. This paper reviews the cutting-edge trends in nano-immunoengineering for metastatic cancers with an emphasis on different nano-immunotherapeutic strategies. Specifically, it discusses directly reversing the immunological status of the primary tumor, harnessing the potential of peripheral immune cells, preventing the formation of a pre-metastatic niche, and inhibiting the tumor recurrence through postoperative immunotherapy. Finally, we describe the challenges facing the integration of nanoscale immunomodulators and provide a forward-looking perspective on the innovative nanotechnology-based tools that may ultimately prove effective at eradicating metastatic diseases.

10.
J Phys Chem Lett ; 12(29): 7067-7075, 2021 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-34291946

RESUMEN

Near-infrared persistent luminescent (or afterglow) nanoparticles with the biologically appropriate size are promising materials for background-free imaging applications, while the conventional batch synthesis hardly allows for reproducibility in controlling particle size because of the random variations of reaction parameters. Here, highly efficient chemistry was matched with an automated continuous flow approach for directly synthesizing differently sized ZnGa2O4:Cr3+ (ZGC) nanoparticles exhibiting long persistent luminescence. The key flow factors responsible for regulating the particle formation process, especially the high pressure-temperature and varied residence time, were investigated to be able to tune the particle size from 2 to 6 nm and to improve the persistent luminescence. Upon silica shell encapsulation of the nanoparticles accompanied by an annealing process, the persistent luminescence of the resulting particles was remarkably enhanced. High-fidelity automated flow chemistry demonstrated here offers an alternative for producing ZGC nanoparticles and will be helpful for other compositionally complex metal oxide nanoparticles.

11.
Adv Sci (Weinh) ; 8(8): 2004044, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33898188

RESUMEN

Hypoxia is considered as a key microenvironmental feature of solid tumors. Luminescent transition metal complexes particularly those based on iridium and ruthenium have shown remarkable potentials for constructing sensitive oxygen-sensing probes due to their unique oxygen quenching pathway. However, the low aqueous solubility of these complexes largely retards their sensing applications in biological media. Moreover, it remains difficult so far to use the existing complexes typically possessing only one luminescent domain to quantitatively detect the intratumoral hypoxia degree. Herein, an Ir(III) complex showing red emissions is designed and synthesized, and innovatively encapsulated within a hydrophobic pocket of Cyanine7-modified cyclodextrin. The Ir(III) complex enables the oxygen detection, while the cyclodextrin is used not only for improving the water solubility and suppressing the luminescence quenching effect of the surrounding aqueous media, but also for carrying Cyanine7 to establish a ratiometric oxygen fluorescence probe. 2D nuclear magnetic resonance is carried out to confirm the host-guest structure. The oxygen-responsive ability of the resulting ratiometric probe is evaluated through in vitro cell and multicellular experiments. Further animal studies about tumor oxygen level mapping demonstrate that the probe can be successfully used for quantitatively visualizing tumor hypoxia in vivo.


Asunto(s)
Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/fisiopatología , Ciclodextrinas , Iridio , Espectroscopía de Resonancia Magnética/métodos , Hipoxia Tumoral/fisiología , Animales , Modelos Animales de Enfermedad , Colorantes Fluorescentes , Humanos , Luminiscencia , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos
12.
Nanoscale ; 13(18): 8514-8523, 2021 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-33908437

RESUMEN

Spinel oxide nanocrystals are appealing hosts for Cr3+ for forming persistent luminescent nanomaterials due to their suitable fundamental bandgaps. Benefiting from their antisite defect-tolerant nature, zinc gallate doped with Cr3+ ions has become the most studied near-infrared (NIR) persistent luminescent material. However, it remains challenging to achieve persistent luminescence from its inexpensive analogs, e.g., zinc aluminate (ZnAl2O4). Because the radius difference of the cations in the latter system is bigger, it is intrinsically unfavorable for ZnAl2O4 to form Zn-Al antisite defects under mild conditions. Herein, we report a wet-chemical synthetic route for preparing Cr3+-doped ZnAl2O4 nanoparticles with long NIR persistent luminescence. It was demonstrated that methanol (MeOH) as an important component of the mixed solvent played a critical role in tailoring the morphology of the resulting ZnAl2O4:Cr nanocrystals. It could particularly drive the formation of antisite defects in the resulting coral-like nanoparticles bearing zinc-rich cores and zinc gradient peripheries. To disclose the effects of MeOH on the formation of antisite defects as well as particle morphologies, small molecules released during the pyrolysis of metal acetylacetonate precursors were analyzed by using gas chromatography-mass spectrometry. In combination with density functional theory (DFT) calculations, it was found that MeOH can effectively catalyze the thermolysis of metal acetylacetonate precursors, in particular Zn(acac)2. Therefore, MeOH exhibits remarkable effects on the formation of antisite defects by balancing the decomposition rates of Zn(acac)2 and Al(acac)3 through its volume fraction in the reaction system. This work thus constitutes a hitherto less common strategy for achieving NIR persistent luminescence from Cr3+-doped ZnAl2O4 nanoparticles by engineering the cation defects under mild conditions.

13.
ACS Nano ; 15(1): 873-883, 2021 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-33404214

RESUMEN

Ultrathin two-dimensional (2D) semiconductors exhibit outstanding properties, but it remains challenging to obtain monolayer-structured inorganic semiconductors naturally occurring as nonlayered crystals. Copper sulfides are a class of widely studied nonlayered metal chalcogenide semiconductors. Although 2D copper sulfides can provide extraordinary physical and chemical applications, investigations of 2D copper sulfides in the extreme quantum limit are constrained by the difficulty in preparing monolayered copper sulfides. Here, we report a subnanometer-thin quasi-copper-sulfide (q-CS) semiconductor formed upon self-assembly of copper(I)-dodecanethiol complexes. Extended X-ray absorption fine structure analysis revealed that the existence of Cu-Cu bonding endowed the layer-structured q-CS with semiconductor properties, such as appreciable interband photoluminescence. Theoretical studies on the band structure demonstrated that the optical properties of copper-dodecanethiol assemblies were dominated by the q-CS layer and the photoluminescence originated from exciton radiative recombination across an indirect band gap, borne out by experimental observation at higher temperatures, but with the onset of a direct emission process at cryogenic temperatures. The following studies revealed that the metal-metal bonding occurred not only in copper-alkanethiolate complex assemblies with variable alkyl chain length but also in silver-alkanethiolate and cadmium-alkanethiolate assemblies. Therefore, the current studies may herald a class of 2D semiconductors with extremely thin thickness out of nonlayered metal sulfides to bridge the gap between conventional inorganic semiconductors and organic semiconductors.

15.
Front Chem ; 8: 832, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33173764

RESUMEN

The rare-earth nanocrystals containing Er3+ emitters offer very promising tools for imaging applications, as they can not only exhibit up-conversion luminescence but also down-conversion luminescence in the second near-infrared window (NIR II). Doping non-lanthanide cations into host matrix was demonstrated to be an effective measure for improving the luminescence efficiency of Er3+ ions, while still awaiting in-depth investigations on the effects of dopants especially those with high valence states on the optical properties of lanthanide nanocrystals. To address this issue, tetravalent Zr4+ doped hexagonal NaGdF4:Yb,Er nanocrystals were prepared, and the enhancement effects of the Zr4+ doping level on both up-conversion luminescence in the visible window and down-conversion luminescence in NIR II window were investigated, with steady-state and transient luminescence spectroscopies. The key role of the local crystal field distortions around Er3+ emitters was elucidated in combination with the results based on both of Zr4+ and its lower valence counterparts, e.g., Sc3+, Mg2+, Mn2+. Univalent ions such as Li+ was utilized to substitute Na+ ion rather than Gd3+, and the synergistic effects of Zr4+ and Li+ ions by co-doping them into NaGdF4:Yb,Er nanocrystals were investigated toward optimal enhancement. Upon optimization, the up-conversion emission of co-doped NaGdF4:Yb,Er nanocrystals was enhanced by more than one order of magnitude compared with undoped nanocrystals. The current studies thus demonstrate that the local crystal field surrounding emitters is an effective parameter for manipulating the luminescence of lanthanide emitters.

16.
J Mater Chem B ; 2020 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-33021617

RESUMEN

Correction for 'Enabling nanopore technology for sensing individual amino acids by a derivatization strategy' by Xiaojun Wei et al., J. Mater. Chem. B, 2020, 8, 6792-6797, DOI: 10.1039/D0TB00895H.

17.
ACS Nano ; 14(9): 12113-12124, 2020 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-32790340

RESUMEN

Benefiting from near-infrared persistent luminescence, chromium-doped zinc gallate nanoparticles have become appealing for background-free biomedical imaging applications, where autofluorescence from adjacent tissues no longer poses a problem. Nevertheless, the synthesis of persistent luminescent nanoparticles with controllable and biologically appropriate size, high luminescence intensity, and long persistent duration remains very challenging. Herein, we report a solvothermal synthetic route for preparing differently sized ZnGa2O4:Cr nanoparticles with a particle size tunable from 4 to 31 nm and afterglow duration longer than 20 h. The route involves lower reaction temperatures and involves no reworking of the particles postsynthesis, providing materials that have far fewer unwanted defects and much higher luminescence yields (up to 51%). It was found that methanol played a paramount role in obtaining the Cr3+-doped ZnGa2O4 nanoparticles. The effects of methanol were discussed in combination with NMR spectroscopy studies and theoretical calculations, and the underlying alcohol-mediated growth and doping mechanisms were elucidated, which will be beneficial for developing highly persistent luminescent nanoparticles.

18.
J Mater Chem B ; 8(31): 6792-6797, 2020 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-32495805

RESUMEN

Nanopore technology holds remarkable promise for sequencing proteins and peptides. To achieve this, it is necessary to establish a characteristic profile for each individual amino acid through the statistical description of its translocation process. However, the subtle molecular differences among all twenty amino acids along with their unpredictable conformational changes at the nanopore sensing region result in very low distinguishability. Here we report the electrical sensing of individual amino acids using an α-hemolysin nanopore based on a derivatization strategy. Using derivatized amino acids as detection surrogates not only prolongs their interactions with the sensing region, but also improves their conformational variation. Furthermore, we show that distinct characteristics including current blockades and dwell times can be observed among all three classes of amino acids after 2,3-naphthalenedicarboxaldehyde (NDA)- and 2-naphthylisothiocyanate (NITC)-derivatization, respectively. These observable characteristics were applied towards the identification and differentiation of 9 of the 20 natural amino acids using their NITC derivatives. The method demonstrated herein will pave the way for the identification of all amino acids and further protein and peptide sequencing.


Asunto(s)
Aminoácidos/análisis , Aminoácidos/química , Nanoporos , Nanotecnología/instrumentación , Proteínas de Escherichia coli/química , Proteínas Hemolisinas/química , Límite de Detección , Conformación Proteica
19.
ACS Appl Mater Interfaces ; 12(10): 11934-11944, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-31975580

RESUMEN

Epitaxially growing a semiconductor shell on the surface of upconversion nanocrystals to form a core/shell structure is believed to be a promising strategy to improve the luminescent efficiency of lanthanide ions doped in particle cores and, meanwhile, enriches the optical properties of the resulting nanocrystals. However, liquid-phase synthesis of such core/shell-structured nanocrystals comprised of a lanthanide ion-doped core and semiconductor shell remains challenging because of the chemical incompatibilities between lanthanides and the most intermediate gap semiconductors. In this context, the successful growth of ZnS shell on a KMnF3 core codoped with Yb3+/Er3+ ions is reported to enhance the upconversion luminescence of Er3+ ions. The underlying core/shell formation mechanism is elucidated in detail combining the hard-soft acid-base theory with structural analysis of the resulting nanocrystals. Quite unexpectedly, Mn2+ diffusion across the core/shell interface occurs during ZnS shell growth, giving rise to Mn2+ emission from the ZnS shell. Thus, the resulting core/shell particles exhibited unique up/downconversion luminescence from doped lanthanide metal ions and transition-metal ions, respectively. By manipulating the ion diffusion and shell growth kinetics, the upconversion and downconversion luminescent performance of KMnF3:Yb,Er@ZnS nanocrystals are further optimized and the related mechanisms are discussed. Further, temperature-dependent upconversion and downconversion photoluminescence properties of KMnF3:Yb,Er@ZnS nanocrystals show potential for ratiometric luminescence temperature sensing.

20.
ACS Appl Bio Mater ; 3(6): 3785-3791, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35025248

RESUMEN

In nature, antifreeze proteins (AFPs) present in plants, fish, and insects living in cold regions exhibit unique abilities to decrease the freezing temperature of water, inhibiting ice growth and recrystallization. However, AFPs suffer from difficult extraction, low stability, and potential immunogenicity, which limit their wide applications in cryopreservation. Thus, AFP-inspired cryoprotectants with low cytotoxicity, simple design, and large-scale production are highly desired. Herein, carbon dots (CDs) from glucose (G-CDs) are synthesized by hydrothermal carbonization. The adsorption on ice crystals provides the G-CDs with an ice-shaping effect while inhibiting ice growth and recrystallization. The high inhibition of ice recrystallization activity and low cytotoxicity of the G-CDs make them promising cryoprotectant materials. Thus, G-CDs without any organic solvent can significantly improve sheep red blood cell recovery to ca. 60%. The use of glucose as a starting material provides these G-CDs with low-cost, biocompatibility, commercial availability, and mass-production characteristics, paving the way for the synthesis of both cryopreservation material CDs from sugars.

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