Composite Fiber Networks Based on Polycaprolactone and Bioactive Glass-Ceramics for Tissue Engineering Applications

In this work, composite fibers connected in three-dimensional porous scaffolds were fabricated by electrospinning, starting from polycaprolactone and inorganic powders synthesized by the sol-gel method. The aim was to obtain materials dedicated to the field of bone regeneration, with controllable properties of bioresorbability and bioactivity. The employed powders were nanometric and of a glass-ceramic type, a fact that constitutes the premise of a potential attachment to living tissue in the physiological environment. The morphological characterization performed on the composite materials validated both the fibrous character and oxide powder distribution within the polymer matrix. Regarding the biological evaluation, the period of immersion in simulated body fluid led to the initiation of polymer degradation and a slight mineralization of the embedded particles, while the osteoblast cells cultured in the presence of these scaffolds revealed a spatial distribution at different depths and a primary networking tendency, based on the composites’ geometrical and dimensional features.

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Luminescence of SiO2-BaF2:Tb3+, Eu3+ Nano-Glass-Ceramics Made from Sol–Gel Method at Low Temperature

Nanomaterials ◽

10.3390/nano12020259 ◽

2022 ◽

Vol 12 (2) ◽

pp. 259

Author(s):

Natalia Pawlik ◽

Barbara Szpikowska-Sroka ◽

Tomasz Goryczka ◽

Ewa Pietrasik ◽

Wojciech A. Pisarski

Keyword(s):

Sol Gel ◽

Three Dimensional ◽

Glass Ceramics ◽

Emission Spectra ◽

Scanning Calorimetry ◽

Light Emitting ◽

Co Doping ◽

Dsc Measurements ◽

Decay Times

The synthesis and characterization of multicolor light-emitting nanomaterials based on rare earths (RE3+) are of great importance due to their possible use in optoelectronic devices, such as LEDs or displays. In the present work, oxyfluoride glass-ceramics containing BaF2 nanocrystals co-doped with Tb3+, Eu3+ ions were fabricated from amorphous xerogels at 350 °C. The analysis of the thermal behavior of fabricated xerogels was performed using TG/DSC measurements (thermogravimetry (TG), differential scanning calorimetry (DSC)). The crystallization of BaF2 phase at the nanoscale was confirmed by X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM), and the changes in silicate sol–gel host were determined by attenuated total reflectance infrared (ATR-IR) spectroscopy. The luminescent characterization of prepared sol–gel materials was carried out by excitation and emission spectra along with decay analysis from the 5D4 level of Tb3+. As a result, the visible light according to the electronic transitions of Tb3+ (5D4 → 7FJ (J = 6–3)) and Eu3+ (5D0 → 7FJ (J = 0–4)) was recorded. It was also observed that co-doping with Eu3+ caused the shortening in decay times of the 5D4 state from 1.11 ms to 0.88 ms (for xerogels) and from 6.56 ms to 4.06 ms (for glass-ceramics). Thus, based on lifetime values, the Tb3+/Eu3+ energy transfer (ET) efficiencies were estimated to be almost 21% for xerogels and 38% for nano-glass-ceramics. Therefore, such materials could be successfully predisposed for laser technologies, spectral converters, and three-dimensional displays.

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Morphological Characterization of Nanofibers: Methods and Application in Practice

Journal of Nanomaterials ◽

10.1155/2012/327369 ◽

2012 ◽

Vol 2012 ◽

pp. 1-14 ◽

Cited By ~ 50

Author(s):

Jakub Širc ◽

Radka Hobzová ◽

Nina Kostina ◽

Marcela Munzarová ◽

Martina Juklíčková ◽

...

Keyword(s):

Specific Surface ◽

Mercury Porosimetry ◽

Three Dimensional ◽

Nitrogen Adsorption ◽

Morphological Characterization ◽

Biologically Active ◽

Porous Scaffolds ◽

Electrospinning Technique ◽

Pore Size Distributions

Biomedical applications such as wound dressing for skin regeneration, stem cell transplantation, or drug delivery require special demands on the three-dimensional porous scaffolds. Besides the biocompatibility and mechanical properties, the morphology is the most important attribute of the scaffold. Specific surface area, volume, and size of the pores have considerable effect on cell adhesion, growth, and proliferation. In the case of incorporated biologically active substances, their release is also influenced by the internal structure of nanofibers. Although many scientific papers are focused on the preparation of nanofibers and evaluation of biological tests, the morphological characterization was described just briefly as service methods. The aim of this paper is to summarize the methods applicable for morphological characterization of nanofibers and supplement it by the results of our research. Needleless electrospinning technique was used to prepare nanofibers from polylactide, poly(ε-caprolactone), gelatin, and polyamide. Scanning electron microscopy was used to evaluate the fiber diameters and to reveal eventual artifacts in the nanofibrous structure. Nitrogen adsorption/desorption measurements were employed to measure the specific surface areas. Mercury porosimetry was used to determine total porosities and compare pore size distributions of the prepared samples.

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Morphological Characterization of 3D Porous Scaffolds Based on Portland Cement

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.396-398.687 ◽

2008 ◽

Vol 396-398 ◽

pp. 687-690 ◽

Cited By ~ 2

Author(s):

Alexandra A.P. Mansur ◽

Herman S. Mansur

Keyword(s):

Portland Cement ◽

Three Dimensional ◽

Morphological Characteristics ◽

Bone Substitutes ◽

Morphological Characterization ◽

Porous Scaffolds ◽

Air Voids ◽

Total Immersion ◽

Potential Use

There is a constant need for bone substitutes. This work was focused on evaluating morphological characteristics of new bioceramic three-dimensional scaffold for bone tissue engineering based on Portland cement with air-voids introduced by outgassing reaction product from lime and aluminum powder. Pores morphology was observed using scanning electron microscopy (SEM). Bulk density, apparent density, and apparent porosity were measured by Archimedes method. Water absorption by total immersion and by capillarity was also investigated. The results have indicated that cement based scaffolds exhibit a hierarchical structure with interconnected macropores and a micropores framework that indicate potential use of the developed porous materials as bone substitutes.

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Construction of the Cellulose Nanofibers (CNFs) Aerogel Loading TiO2 NPs and Its Application in Disposal of Organic Pollutants

Polymers ◽

10.3390/polym13111841 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1841

Author(s):

Kang Li ◽

Xuejie Zhang ◽

Yan Qin ◽

Ying Li

Keyword(s):

High Efficiency ◽

Sol Gel ◽

Cellulose Nanofibers ◽

Three Dimensional ◽

Good Mechanical Property ◽

Polar Groups ◽

Dimensional Network ◽

Natural Polysaccharide ◽

Valuable Method ◽

Adsorption Capability

Aerogels have been widely used in the adsorption of pollutants because of their large specific surface area. As an environmentally friendly natural polysaccharide, cellulose is a good candidate for the preparation of aerogels due to its wide sources and abundant polar groups. In this paper, an approach to construct cellulose nanofibers aerogels with both the good mechanical property and the high pollutants adsorption capability through chemical crosslinking was explored. On this basis, TiO2 nanoparticles were loaded on the aerogel through the sol-gel method followed by the hydrothermal method, thereby the enriched pollutants in the aerogel could be degraded synchronously. The chemical cross-linker not only helps build the three-dimensional network structure of aerogels, but also provides loading sites for TiO2. The degradation efficiency of pollutants by the TiO2@CNF Aerogel can reach more than 90% after 4 h, and the efficiency is still more than 70% after five cycles. The prepared TiO2@CNF Aerogels have high potential in the field of environmental management, because of the high efficiency of treating organic pollutes and the sustainability of the materials. The work also provides a choice for the functional utilization of cellulose, offering a valuable method to utilize the large amount of cellulose in nature.

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Hyperspectral Three-Dimensional Fluorescence Imaging Using Snapshot Optical Tomography

Sensors ◽

10.3390/s21113652 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3652

Author(s):

Cory Juntunen ◽

Isabel M. Woller ◽

Yongjin Sung

Keyword(s):

Fourier Transform ◽

3D Imaging ◽

Optical Tomography ◽

Three Dimensional ◽

High Spectral Resolution ◽

Functional Information ◽

Fluorescent Beads ◽

Different Depths ◽

Projection Images ◽

Imaging Performance

Hyperspectral three-dimensional (3D) imaging can provide both 3D structural and functional information of a specimen. The imaging throughput is typically very low due to the requirement of scanning mechanisms for different depths and wavelengths. Here we demonstrate hyperspectral 3D imaging using Snapshot projection optical tomography (SPOT) and Fourier-transform spectroscopy (FTS). SPOT allows us to instantaneously acquire the projection images corresponding to different viewing angles, while FTS allows us to perform hyperspectral imaging at high spectral resolution. Using fluorescent beads and sunflower pollens, we demonstrate the imaging performance of the developed system.

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Construction of a Three-Dimensional BaTiO3 Network for Enhanced Permittivity and Energy Storage of PVDF Composites

Materials ◽

10.3390/ma14133585 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3585

Author(s):

Xueqing Bi ◽

Lujia Yang ◽

Zhen Wang ◽

Yanhu Zhan ◽

Shuangshuang Wang ◽

...

Keyword(s):

Energy Storage ◽

Polyvinylidene Fluoride ◽

Dielectric Breakdown ◽

Breakdown Strength ◽

Sol Gel ◽

Three Dimensional ◽

Low Dielectric ◽

Energy Storage Properties ◽

Discharge Energy Density ◽

Pure Pvdf

Three-dimensional BaTiO3 (3D BT)/polyvinylidene fluoride (PVDF) composite dielectrics were fabricated by inversely introducing PVDF solution into a continuous 3D BT network, which was simply constructed via the sol-gel method using a cleanroom wiper as a template. The effect of the 3D BT microstructure and content on the dielectric and energy storage properties of the composites were explored. The results showed that 3D BT with a well-connected continuous network and moderate grain sizes could be easily obtained by calcining a barium source containing a wiper template at 1100 °C for 3 h. The as-fabricated 3D BT/PVDF composites with 21.1 wt% content of 3D BT (3DBT–2) exhibited the best comprehensive dielectric and energy storage performances. An enhanced dielectric constant of 25.3 at 100 Hz, which was 2.8 times higher than that of pure PVDF and 1.4 times superior to the conventional nano–BT/PVDF 25 wt% system, was achieved in addition with a low dielectric loss of 0.057 and a moderate dielectric breakdown strength of 73.8 kV·mm−1. In addition, the composite of 3DBT–2 exhibited the highest discharge energy density of 1.6 × 10−3 J·cm−3 under 3 kV·mm−1, which was nearly 4.5 times higher than that of neat PVDF.

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Macroporous chitosan/methoxypoly(ethylene glycol) based cryosponges with unique morphology for tissue engineering applications

Scientific Reports ◽

10.1038/s41598-021-82484-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Pradeep Kumar ◽

Viness Pillay ◽

Yahya E. Choonara

Keyword(s):

Tissue Engineering ◽

Polymer Network ◽

Three Dimensional ◽

Hysteresis Loops ◽

Interpenetrating Polymer Network ◽

Morphological Data ◽

Porous Scaffolds ◽

Morphological Variations ◽

Molecular Stability ◽

The Matrix

AbstractThree-dimensional porous scaffolds are widely employed in tissue engineering and regenerative medicine for their ability to carry bioactives and cells; and for their platform properties to allow for bridging-the-gap within an injured tissue. This study describes the effect of various methoxypolyethylene glycol (mPEG) derivatives (mPEG (-OCH3 functionality), mPEG-aldehyde (mPEG-CHO) and mPEG-acetic acid (mPEG-COOH)) on the morphology and physical properties of chemically crosslinked, semi-interpenetrating polymer network (IPN), chitosan (CHT)/mPEG blend cryosponges. Physicochemical and molecular characterization revealed that the –CHO and –COOH functional groups in mPEG derivatives interacted with the –NH2 functionality of the chitosan chain. The distinguishing feature of the cryosponges was their unique morphological features such as fringe thread-, pebble-, curved quartz crystal-, crystal flower-; and canyon-like structures. The morphological data was well corroborated by the image processing data and physisorption curves corresponding to Type II isotherm with open hysteresis loops. Functionalization of mPEG had no evident influence on the macro-mechanical properties of the cryosponges but increased the matrix strength as determined by the rheomechanical analyses. The cryosponges were able to deliver bioactives (dexamethasone and curcumin) over 10 days, showed varied matrix degradation profiles, and supported neuronal cells on the matrix surface. In addition, in silico simulations confirmed the compatibility and molecular stability of the CHT/mPEG blend compositions. In conclusion, the study confirmed that significant morphological variations may be induced by minimal functionalization and crosslinking of biomaterials.

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