scholarly journals Analytical Techniques for the Characterization of Bioactive Coatings for Orthopaedic Implants

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1936
Author(s):  
Katja Andrina Kravanja ◽  
Matjaž Finšgar

The development of bioactive coatings for orthopedic implants has been of great interest in recent years in order to achieve both early- and long-term osseointegration. Numerous bioactive materials have been investigated for this purpose, along with loading coatings with therapeutic agents (active compounds) that are released into the surrounding media in a controlled manner after surgery. This review initially focuses on the importance and usefulness of characterization techniques for bioactive coatings, allowing the detailed evaluation of coating properties and further improvements. Various advanced analytical techniques that have been used to characterize the structure, interactions, and morphology of the designed bioactive coatings are comprehensively described by means of time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), 3D tomography, quartz crystal microbalance (QCM), coating adhesion, and contact angle (CA) measurements. Secondly, the design of controlled-release systems, the determination of drug release kinetics, and recent advances in drug release from bioactive coatings are addressed as the evaluation thereof is crucial for improving the synthesis parameters in designing optimal bioactive coatings.

Author(s):  
O. SREEKANTH REDDY ◽  
M. C. S. SUBHA ◽  
T. JITHENDRA ◽  
C. MADHAVI ◽  
K. CHOWDOJI RAO ◽  
...  

Objective: The aim of the present study was to fabricate and evaluate the drug release studies using Sodium Alginate (SA) and Gelatin (GE) microbeads intercalated with Kaolin (KA) nanoclay for sustained release of D-Penicillamine (D-PA). Methods: Sodium alginate/gelatin/Kaolin blend microbeads were prepared by an extrusion method by using glutaraldehyde (GA) as a crosslinker. The obtained microbeads were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X–ray diffraction (XRD). Drug release kinetics of the microbeads was investigated in simulated intestinal fluid (pH 7.4) at 37 °C. Results: Microbeads formation was confirmed by FTIR spectroscopy. X-RD reveals that the KA should be intercalated with the drug and also it confirms the molecular level dispersion of D-Penicillamine into microbeads. Scanning Electron Microscopy (SEM) studies reveal that the beads were in spherical shape with some wrinkled depressions on the surface. The in vitro release study indicates the D-Penicillamine released in a controlled manner. The in vitro release kinetics was assessed by Korsmeyer-Peppas equation and the ‘n’ value lies in between 0.557-0.693 indicates Non-Fickian diffusion process. Conclusion: The results suggest that the developed KA intercalated microbeads are good potential drug carrier for the controlled release of D-PA.


Author(s):  
Tassew Belete Bahru ◽  
Eyasu Gebrie Ajebe

The combination of nanotechnology with molecular biology, information technology and instrumentation, is opening the door to a new industrial age. The aim of this review article is to summarize the current knowledge of nanotechnology in synthesizing, identifying and characterization of nanomaterials using analytical techniques. Physical and chemical approach synthesis of nanomaterials befalls challenges in the development of analytical techniques used to characterize them. The major techniques include: Transmission Electron Microscopy, Scanning Electron Microscopy, Atomic Force Microscopy, Dynamic Light Scattering, X ray Photoelectron Spectroscopy, X-ray Diffraction, Single Phase Inductively Coupled Plasma Mass Spectroscopy, X ray Fluorescence Spectroscopy, Auger Electron Spectroscopy, X ray Absorption Fine Structure, Capillary Electrophoretic Separations, Magnetic nano particles coupled HPLC and Dynamic light scattering. Nanomaterials have been characterized for the extensive potential applications in optics, electronics, magnetics, and catalysts; chemical sensing, biomedicine, micro reactor, and they have been applied in food, biological, environmental and pharmaceuticals uses. In spite of the extended use of nano particles in diverse consumer products, there is a great concern over the unexpected impact or effects on humans due to exposure.


2020 ◽  
Vol 10 (4) ◽  
pp. 518-533 ◽  
Author(s):  
Kehinde M. Ibiyeye ◽  
Abu B.Z. Zuki ◽  
Norshariza Nurdin ◽  
Mokrish Ajat

Background: Cockleshell-derived aragonite calcium carbonate nanoparticles were prepared by the top-down approach for combine delivery of two types of drugs. Objective: The aim of this study was to synthesize and characterize thymoquinone-doxorubicin loaded cockle shell-derived aragonite calcium carbonate nanoparticle. Aragonite calcium carbonate nanoparticles encapsulating thymoquinone and doxorubicin alone were also prepared. Methods: The blank and drug-loaded nanoparticles were characterized by field emission scanning electron microscopy, transmission electron microscopy, Zeta potential, Fourier transformed infrared and X-ray diffraction. Drug delivery properties, in vitro drug release study at pH 7.4, 6 and 4.8, and effect of blank nanoparticles on MCF10A, 3T3, MDA MB231 cells were also analyzed. Results: The blank and drug-loaded nanoparticles were pleomorphic and their sizes varying from 53.65 ± 10.29 nm to 60.49 ± 11.36 nm with an overall negative charge. The entrapment efficiency of thymoquinone and doxorubicin were 41.6 and 95.8, respectively. The FTIR showed little alteration after loading thymoquinone and doxorubicin while XRD patterns revealed no changes in the crystallizations of nanoparticles after drug loading. The drug release kinetics of doxorubicin and thymoquinone from the nanoparticles showed a continuous and gradual release after an initial burst release was observed. At pH 4.8, about 100% of drug release was noticed, 70% at pH 6 while only 50% at pH 7.4. The cell viability was 80% at a concentration of 1000 ug/ml of blank nanoparticle. Conclusion: The cockle shell-derived pH sensitive aragonite calcium carbonate nanoparticle provides an effective and simple means of multiple drug delivery and function as a platform for pH controlled release of loaded therapeutic agents.


2008 ◽  
Vol 80 (11) ◽  
pp. 2327-2343 ◽  
Author(s):  
V. Subramanian ◽  
Hongwei Zhu ◽  
Bingqing Wei

Manganese oxides have been synthesized by a variety of techniques in different nanostructures and studied for their properties as electrode materials in two different storage applications, supercapacitors (SCs) and Li-ion batteries. The composites involving carbon nanotubes (CNTs) and manganese oxides were also prepared by a simple room-temperature method and evaluated as electrode materials in the above applications. The synthesis of nanostructured manganese oxides was carried out by simple soft chemical methods without any structure directing agents or surfactants. The prepared materials were well characterized using different analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), surface area studies, etc. The electrochemical properties of the nanostructured manganese oxides and their composites were studied using cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopic (EIS) studies. The influence of structural/surface properties on the electrochemical performance of the synthesized manganese oxides is reviewed.


Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 103 ◽  
Author(s):  
Christian Tolle ◽  
Jan Riedel ◽  
Carina Mikolai ◽  
Andreas Winkel ◽  
Meike Stiesch ◽  
...  

Nanoparticles can be used as a smart drug delivery system, when they release the drug only upon degradation by specific enzymes. A method to create such responsive materials is the formation of hydrogel nanoparticles, which have enzymatically degradable crosslinkers. Such hydrogel nanoparticles were prepared by ionotropic gelation sodium alginate with lysine-rich peptide sequences—either α-poly-L-lysine (PLL) or the aggrecanase-labile sequence KKKK-GRD-ARGSV↓NITEGE-DRG-KKKK. The nanoparticle suspensions obtained were analyzed by means of dynamic light scattering and nanoparticle tracking analysis. Degradation experiments carried out with the nanoparticles in suspension revealed enzyme-induced lability. Drugs present in the polymer solution during the ionotropic gelation can be encapsulated in the nanoparticles. Drug loading was investigated for interferon- (IFN-) as a model, using a bioluminescence assay with MX2Luc2 cells. The encapsulation efficiency for IFN- was found to be approximately 25%. The nanoparticles suspension can be used to spray-coat titanium alloys (Ti-6Al-4V) as a common implant material. The coatings were proven by ellipsometry, reflection-absorption infrared spectroscopy, and X-ray photoelectron spectroscopy. An enzyme-responsive decrease in layer thickness is observed due to the degradation of the coatings. The Alg/peptide coatings were cytocompatible for human gingival fibroblasts (HGFIB), which was investigated by CellTiterBlue and lactate dehydrogenase (LDH) assay. However, HGFIBs showed poor adhesion and proliferation on the Alg/peptide coatings, but these could be improved by modification of the alginate with a RGD-peptide sequence. The smart drug release system presented can be further tailored to have the right release kinetics and cell adhesion properties.


1985 ◽  
Vol 50 ◽  
Author(s):  
S. Myhra ◽  
R. L. Segall ◽  
R. ST. C. Smart ◽  
P. S Turner ◽  
T. J. White

AbstractHigh resolution electron microscopy and scanning electron microscopy were used to determine the distribution of intergranular films and microvoids in Synroc C. Diffraction contrast derived from these films, which were 1–3 nm thick, showed then to be ill-defined crystallographically, and they may be described as glassy. Pores were usually several micrometers in extent and occurred principally in rutile-rich areas. The chemical composition of these structural features was obtained using analytical transmission electron microscopy, secondary ion mass spectrometry, x-ray photoelectron spectroscopy and scanning Auger microscopy. Within intergranular films, elemental enhancement of cesium, sodium, potassium and aluminium, and possibly silicon and molybdenum was observed. Enhancement of cesium, sodium, phosphorous, aluminium and silicon was found at triple points. Fracture faces preferentially expose grain boundaries, and dissolution of these surfaces proceeds rapidly at ambient temperatures. During the fabrication of Synroc C, microvoids trap cesium vapour, and after cooling this condenses onto pore surfaces. Recognition of the (simulated) waste species which segregate at grain boundaries and pores, permitted the reinterpretation of published leach data for monolithic and crushed Synroc C.


2021 ◽  
Vol 12 ◽  
pp. 1365-1371
Author(s):  
Vladislav Dřínek ◽  
Stanislav Tiagulskyi ◽  
Roman Yatskiv ◽  
Jan Grym ◽  
Radek Fajgar ◽  
...  

Chemical vapor deposition was applied to synthetize nanostructured deposits containing several sorts of nanoobjects (i.e., nanoballs, irregular particles, and nanowires). Analytical techniques, that is, high-resolution transmission electron microscopy, scanning electron microscopy, electron dispersive X-ray analysis, selected area electron diffraction, and X-ray photoelectron spectroscopy, showed that unlike nanoballs and particles composed of crystalline germanium, the layer was made of chromium germanide CrGex. The nanowires possessed a complex structure, namely a thin crystalline germanium core and amorphous CrGex coating. The composition of the nanowire coating was [Cr]/[Ge] = 1:(6–7). The resistance of the nanowire–deposit system was estimated to be 2.7 kΩ·cm using an unique vacuum contacting system.


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