In this work, bioactive glass (BG) particles synthesized by a sol-gel method, hyaluronic acid (HYA) and collagen (COL) extracted from chicken eggshell membrane (ESM), and as-purchased polycaprolactone (PCL) were used to obtain a novel bioactive scaffold using the gel-pressing technique. Two composite mixtures in weight percent were obtained and identified as SCF-1 and SCF-2, and were characterized by using FTIR, XRD, and SEM techniques. Subsequently, the composite materials applied as coatings were evaluated in simulated body fluid solutions using electrochemical techniques. The results of bioactivity and biodegradability evaluations, carried out by immersing in simulated body fluid and phosphate-buffered saline solution, showed that the SCF-1 sample presented the best biocompatibility. In accordance with the potentiodynamic results, the 316L-SS and the SCF-1-coated SS showed a very similar corrosion potential (E corr ), around −228 mV, and current density (i corr ) values in close proximity, while the SCF-2-coated SS showed more positive E corr around −68 mV and lower i corr value in one order of magnitude. These results agree with those obtained by electrochemical impedance spectroscopy, which show a corrosion mechanism governed by activation and finite diffusion through the porous layer. In addition, results were complemented by dynamic compression testing under oscillating forces to identify the developed scaffolds’ response under external forces, where the SCF-1 scaffold presented a maximum compression. The degradation resistance, bioactivity, and mechanically obtained measurements provided interesting results for potential further studies in tissue engineering.

Development of Bioactive Glass-Collagen-Hyaluronic Acid-Polycaprolactone Scaffolds for Tissue Engineering Applications

The limitations associated with the clinical use of autographs and allografts are driving efforts to develop relevant and applicable biomaterial substitutes. In this research, 3D porous scaffolds composed of bioactive glass (BG) obtained through the sol-gel technique and polylactic acid (PLA) synthesized via lactic acid (LA) ring-opening polymerization were prepared by the gel-pressing technique. Two different weight compositions were evaluated, namely, BG70-PLA30 and BG30-PLA70. The structure and morphology of the resulting scaffolds were analysed by FTIR, XRD, SEM, and under ASTM F1635 standard characterizations. The results confirmed that BG promotes the formation of a hydroxy-carbonated apatite (HAp) layer on composites when immersed in simulated body fluid (SBF). Biodegradability evaluations were carried out according to the ISO 10993-13:2010 standard. In addition, electrochemical evaluations were performed in both Hank’s and SBF solutions at 37 °C in order to analyse the degradation of the material. This evaluation allowed us to observe that both samples showed an activation mechanism in the early stages followed by pseudo-passivation due to physical bioactive glass characteristics, suggesting an improvement in the formation of the HAp nucleation. The described composites showed excellent resistance to degradation and outstanding suitability for bone tissue engineering applications.

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Characterization and Evaluation of Composite Biomaterial Bioactive Glass–Polylactic Acid for Bone Tissue Engineering Applications

This paper addresses the chemical synthesis and characterization of a composite formed by Li2O-Al2O3-Al3Fe-Al3Fe5O12/PCL which were obtained by the process of reduction of ferric chloride (FeCl3) with lithium aluminum hydride (LiAlH4) in an open atmosphere. The goal of the development of this hybrid material was to perform a superparamagnetic material with several potential applications. The results of the characterizations by scanning electron microscopy (SEM) and vibrating sample magnetometer showed a Li2O-Al2O3-Al3Fe-Al3Fe5O12 “desert rose stone”-like morphology 3D hierarchical powders formation when particles were sintered at 850 °C. Homogeneous nanometric particles after calcination at 1100 °C were observed. X-ray diffraction analysis were performed to determine their composition. Subsequently, the superparamagnetic powders were added by dispersion in a polycaprolactone (PCL) matrix, and then, were evaluated by SEM for the observation of their morphologies. The composite material presented a polymer network with an opened structure, a well dispersion of the oxides particles into the interstices with irregular topography and reliefs.

Development of a hybrid metal-oxides (Li2O-Al2O3-Al3Fe-Al3Fe5O12) reinforced polycaprolactone composite

Evaluation of the electrochemical behavior of TiO2/Al2O3/PCL composite coatings in Hank’s solution

In this study, a chemical reduction synthesis method of iron aluminum (FeAl) nano-dimensional intermetallic powders is described. The process has two stages: a salt reduction and solvent evaporation by a heat treatment at 1100∘C. The precursors of the synthesis are ferric chloride, aluminum foil chips, a mix of Toluene/THF in a 75/25 volume relationship, and concentrated hydrochloric acid as initiator of the reaction. The reaction time was 20 days, the product obtained was dried at 60 ∘C for 2 h and calcined at 400, 800, and 1100 ∘C for 4 h each. To characterize and confirm the obtained synthesis products, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) techniques were used. The results of morphology and chemical characterization of nano-dimensional powders obtained showed a formation of agglomerated particles of a size range of approximately 150 nm to 1.0 μm. Composition of powders was identified as corundum (Al2O3), iron aluminide (FeAl3), and iron-aluminum oxides (Fe0. 53Al0. 47)2O3 phases. The oxide phases formation were associated with the reaction of atmospheric concentration-free oxygen during synthesis and sintering steps, reducing the concentration of the iron aluminum phase.

L. Ballesteros-Almanza

Papers

Evaluation of the electrochemical behavior of TiO2/Al2O3/PCL composite coatings in Hank’s solution

Chemical Reduction Synthesis of Iron Aluminum Powders