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1.
J Colloid Interface Sci ; 581(Pt A): 21-30, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768732

RESUMO

Lanthanide ion (Ln3+)-doped nanoscale hydroxyapatites (nHAp) with tunable luminescence have attracted increasing attention due to their potential applications as useful biomedical tools (e.g., imaging and clinical therapy). In this study, we reported that doping Terbium (III) ions (Tb3+) in self-activated luminescent nHAp via a facile hydrothermal reaction, using trisodium citrate (Cit3-), generates unique emission-tunable probes known as Cit/Tb-nHAp. The morphology, crystal phase, and luminescence properties of these Cit/Tb-nHAp probes are studied in detail. Moreover, the results demonstrate that the luminescence of self-activated nHAp originates from the carbon dots trapped within the nHAp crystals, in which partial energy transfer occurs from carbon dots (CDs) to Tb3+. The color tunability is successfully achieved by regulating the addition of Cit3-. Biocompatibility study indicates that when co-cultured with C6 glioma cells in vitro for 3 days, ≤800 ppm Cit/Tb-nHAp is not cytotoxic for C6 glioma cells. We also present in vitro data showing efficient cytoplasmic localization of transferrin conjugated Cit/Tb-nHAp into C6 glioma cells by fluorescence cell imaging. We have successfully engineered Cit/Tb-nHAp, a promising biocompatible agent for future in vitro and in vivo fluorescence bioimaging.

2.
Sci Rep ; 10(1): 18636, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33122804

RESUMO

This study was performed to investigate the Eustachian tube as a potential route for contralateral spreading following intratympanic nanoparticle (NP)-conjugated gentamicin injection in a rat model. Sprague-Dawley rats were divided into three groups and substances were injected in the right ear: group 1 (fluorescent magnetic nanoparticles [F-MNPs], n = 4), group 2 (F-MNP-conjugated gentamicin [F-MNP@GM], n = 2), and control group (no injections, n = 2). T2-weighted sequences corresponding to the regions of interest at 1, 2, and 3 h after intratympanic injection were evaluated, along with immunostaining fluorescence of both side cochlea. The heterogeneous signal intensity of F-MNPs and F-MNP@GM on T2-weighted images, observed in the ipsilateral tympanum, was also detected in the contralateral tympanum in 4 out of 6 rats, recapitulating fluorescent nanoparticles in the contralateral cochlear hair cells. Computational simulations demonstrate the contralateral spreading of particles by gravity force following intratympanic injection in a rat model. The diffusion rate of the contralateral spreading relies on the sizes and surface charges of particles. Collectively, the Eustachian tube could be a route for contralateral spreading following intratympanic injection. Caution should be taken when using the contralateral ear as a control study investigating inner-ear drug delivery through the transtympanic approach.

3.
ACS Nano ; 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32298072

RESUMO

The astrophysical phenomenon of mimetic helical magnetic field (hB)-assisted self-assembly is herein introduced to build helical superstructures that display chiroptical properties. As a building block, magnetoplasmonic (MagPlas) Ag@Fe3O4 core-shell nanoparticles are used to guide plasmonic Ag nanoparticles onto a helical magnetic flux. The chirality of the assembled helical structures and tailored circular dichroism are successfully tuned in real time, and the handedness of the assembled structures is dynamically switched by the hB at the millisecond level, which is at least 6000-fold faster than other template-assisted methods. The peak position of circular dichroism can be reconfigured by altering the plasmonic resonance or coupling by controlling the size of the Ag core and magnetic flux density. The hB-induced chirality modulation represents a method to control the polarization state of light at the nexus of plasmonics, magnetic self-assembly, colloidal science, liquid crystals, and chirality. It presents active and dynamic chiral assemblies of magnetoplasmonic nanomaterials, enabling further practical applications in optical devices.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32181632

RESUMO

One-dimensional nanostructures with controllable aspect ratios are essential for a wide range of applications. An approach for magnetic superparticle (SP) assembly over large areas (55 mm × 25 mm) is introduced via co-assistance of electrostatic and magnetic fields, so-called magnetic layer-by-layer assembly, on an arbitrary hydrophilic substrate within minutes. The SP structures [diameter (d) = 120-350 nm] of Fe3O4 or Ag@Fe3O4 composites composed of hundreds of magnetite nanocrystals (d = 10-20 nm) are used as colloidal monomers to fabricate arrays of high aspect ratio (up to 102) linear nanochains, viz. colloidal polymers, where thermal disturbances were minimized. The arrays of colloidal polymers exhibit strong optical polarization effects owing to their geometrical anisotropy, which can be used as a simple optical filter. Furthermore, by using the binary colloidal mixture of different magnetic colloids, including different sized Fe3O4 and magnetoplasmonic Ag@Fe3O4, low aspect ratio (2-15) colloidal chains, viz. magnetic/plasmonic oligomers, with tunable lengths were fabricated, affording a facile but an effective approach to modulate the optical properties of the chains. The scalable fabrication of well-aligned, linear colloidal polymers and oligomers opens up appealing opportunities for the development of sensors, subwavelength waveguides, optical tweezers, and enhanced solar harvesting devices.

5.
J Colloid Interface Sci ; 569: 1-11, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32092600

RESUMO

Whitlockite (WH, Ca18Mg2(HPO4)2(PO4)12) is the second most abundant bone mineral and has attracted attention as one of the novel bone regenerative materials. It has proven to enhance growth and promote osteogenesis of stem cells. However, investigating the mechanism of formation of pure phase WH nanocrystals remains a challenge. In this study, we introduced an interesting synthesis approach of WH nanocrystals using a tri-solvent system for the solid-liquid-solution (SLS) process. The ratio of precursor and reaction solvent composition was optimized to generate WH nanocrystals with tunable size, morphology (nanoplates, nanospheres), and surface properties (hydrophobic, hydrophilic), which is impossible to achieve using the traditional precipitation method. Molecular dynamics (MD) simulations revealed that the growth direction of nanoplates is highly related to the surfactant and its binding affinity. Finite element method (FEM) simulations elucidated that the ratio of ethanol/water plays an important role in defining the crystallinity and morphology of WH. In this study, we demonstrated that the cell proliferation of human bone marrow-derived mesenchymal stem cells (hBMSCs) is enhanced upon treatment with WH. The results of quantitative real-time polymerase chain reaction (qPCR) revealed that WH can positively accelerate the osteogenic differentiation in hBMSCs. The as-synthesized WH has a great potential in the future to be used in osteogenic tissue engineering. This study opens a new horizon for the synthesis and application of WH.


Assuntos
Materiais Biocompatíveis/química , Fosfatos de Cálcio/química , Células-Tronco Mesenquimais/metabolismo , Nanopartículas/química , Tecidos Suporte/química , Regeneração Óssea , Calcificação Fisiológica , Proliferação de Células , Células Cultivadas , Etanol/química , Análise de Elementos Finitos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Simulação de Dinâmica Molecular , Osteogênese , Solventes/química , Propriedades de Superfície , Engenharia Tecidual , Água
6.
ACS Appl Mater Interfaces ; 12(5): 6598-6606, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31922383

RESUMO

The Lorentz or Kelvin force generated by an externally applied magnetic field may introduce additional convection of the electrolyte near the working electrode and consequently produces magnetocurrent (MC), which can be attributed to the magnetohydrodynamic (MHD) flow and an extra electrochemical reaction. A magnetoplasmonic (MagPlas) composite of metallic and superparamagnetic nanoparticles (NPs) with a permanent dipole or magnetic moment have additional degree or order, which corresponds to directional correlation to electric and magnetic dipoles. In particular, an ordered self-assembly may boost up the MHD flow on a collectively reactive surface, leading to remarkable electrochemical performance. In this article, a proof-of-concept work explores the effect of the magnetic field on the electrocatalytic activity of the oxygen reduction reaction (ORR) as well as [Fe(CN)6]3-/4- redox probes using a precisely controlled three-dimensional (3D) nanostructure of a silver core and a porous magnetic shell (Ag@Fe3O4) assembly. Then, the reduction current was carefully monitored in the presence of a magnetic field (B, up to 380 mT), resulting in an extraordinary increment of reduction current (IR) of [Fe(CN)6]3- by 23% and a 1.13-fold high ORR efficiency owing to the additional magnetic field (Bin) from the 3D magnetoplasmonic nanoassembly. The computational simulation explained the plausible mechanism of current enhancement from the MagPlas nanoassembly. From our experimental and computational studies, it is probable that the 3D MagPlas nanoassembly is a unique and efficient catalyst under a low external magnetic field, which would be useful for further biomedical and energy-related applications.

7.
J Biomed Mater Res A ; 105(6): 1736-1745, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28076883

RESUMO

Carbon nanotubes, with their unique and outstanding properties, such as strong mechanical strength and high electrical conductivity, have become very popular for the repair of tissues, particularly for those requiring electrical stimuli. Polydimethylsiloxane (PDMS)-based elastomers have been used in a wide range of biomedical applications because of their optical transparency, physiological inertness, blood compatibility, non-toxicity, and gas permeability. In present study, most of artificial nerve guidance conduits (ANGCs) are not transparent. It is hard to confirm the position of two stumps of damaged nerve during nerve surgery and the conduits must be cut open again to observe regenerative nerves after surgery. Thus, a novel preparation method was utilized to produce a transparent sheet using PDMS and multiwalled carbon nanotubes (MWNTs) via printing transfer method. Characterization of the PDMS/MWNT (PM) sheets revealed their unique physicochemical properties, such as superior mechanical strength, a certain degree of electrical conductivity, and high transparency. Characterization of the in vitro and in vivo usability was evaluated. PM sheets showed high biocompatibility and adhesive ability. In vivo feasibility tests of rat brain tissue and sciatic nerve revealed the high transparency of PM sheets, suggesting that it can be used in the further development of ANGCs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1736-1745, 2017.


Assuntos
Encéfalo/fisiologia , Materiais Revestidos Biocompatíveis/química , Dimetilpolisiloxanos/química , Regeneração Tecidual Guiada/métodos , Nanotubos de Carbono/química , Nervo Isquiático/fisiologia , Animais , Adesão Celular , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/toxicidade , Dimetilpolisiloxanos/toxicidade , Humanos , Masculino , Nanotubos de Carbono/toxicidade , Regeneração Nervosa , Ratos Sprague-Dawley
8.
J Biomed Nanotechnol ; 13(12): 1715-1724, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29490759

RESUMO

Many artificial materials have been used for mastoid cavity obliteration in canal wall down tympanomastoidectomy. Among the artificial materials, hydroxyapatite is most popular material for mastoid cavity obliteration. Hydroxyapatite is biostable and osteoconductive, but it has poor mechanical properties, especially brittleness. To overcome the limitation, hydroxyapatite has been combined with natural chitosan polymer, which is biocompatible and flexible, to produce a hydroxyapatite-chitosan patch via a sublimation-assisted compression process. We evaluated this hydroxyapatite-chitosan patch for tympanic cavity obliteration in a rat model by comparing it with sham surgery group, bone cement and homologous cartilage. The cavity obliteration ratio and new bone formation in tympanic bullae were determined by computed tomography, histological analysis, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Comparing the hydroxyapatite-chitosan patch with homologous cartilage and bone cement, the tympanic cavity obliteration ratio was superior in the patch group (40.96 ± 7.79%) than other groups (32.23 ± 6.93% and 16.07 ± 6.10%). Even the hydroxyapatite-chitosan patch made no difference in new bone formation ratio ranging from 27.92 ± 11.08 to 29.17 ± 10.96% with other groups. In conclusion, hydroxyapatite-chitosan patch for mastoid cavity obliteration showed easy handling, flexibility, favorable osteogenesis and biostability.


Assuntos
Quitosana , Durapatita , Processo Mastoide , Timpanoplastia , Animais , Regeneração Óssea , Ratos
9.
J Biomed Mater Res A ; 105(6): 1637-1645, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28032681

RESUMO

Chitosan, produced from chitin, is one of the polymers with promising applications in various fields. However, despite diverse research studies conducted on its biocompatibility, its uses are still limited. The main reason is the degree of deacetylation (DOD), which represents the proportion of deacetylated units in the polymer and is directly correlated with its biocompatibility property. In this article, the in vivo biocompatibility of three chitosan-hydroxyapatite composite films composed of chitosan with different DOD values was investigated by traditional biological protocols and novel optical spectroscopic analyses. The DOD of the chitosan obtained from three different manufacturers was estimated and calculated by Raman spectroscopy, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. The chitosan with the higher DOD induced a higher incidence of inflammation in skin cells. The amino group density, biodegradability, and crystallinity of chitosan are the three possible factors that need to be considered when determining the biocompatibility of the films for in vivo application, as they led to complicated biological results, resulting in either better or worse inflammation even when using chitosan products with the same DOD. This basic study on the relationship between the DOD and inflammation is valuable for the development of further chitosan-based researches. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1637-1645, 2017.


Assuntos
Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , Quitosana/efeitos adversos , Quitosana/química , Durapatita/efeitos adversos , Durapatita/química , Inflamação/induzido quimicamente , Acetilação , Animais , Inflamação/patologia , Espectroscopia de Ressonância Magnética , Masculino , Ratos Sprague-Dawley , Pele/efeitos dos fármacos , Pele/patologia , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Tecidos Suporte/efeitos adversos , Tecidos Suporte/química
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