Implanted biomedical devices can induce adverse responses in the human body, which can cause failure of the implant-referred to as implant failure. Early implant failure is induced numerous factors, ...most importantly, infection and inflammation. Natural products are, today, one of the main sources of new drug molecules due to the development of pathogenic bacterial strains that possess resistance to more antibiotics used currently in various diseases. The aim of this work is the sol⁻gel synthesis of antibacterial biomedical implants. In the silica matrix, different percentages (6, 12, 24, 50 wt %) of polyethylene glycol (PEG) or poly(ε-caprolactone) (PCL) were embedded. Subsequently, the ethanol solutions with high amounts of chlorogenic acid (CGA 20 wt %) were slowly added to SiO₂/PEG and SiO₂/PCL sol. The interactions among different organic and inorganic phases in the hybrid materials was studied by Fourier transform infrared (FTIR) spectroscopy. Furthermore, the materials were soaked in simulated body fluid (SBF) for 21 days and the formation of a hydroxyapatite layer on their surface was evaluated by FTIR and XRD analysis. Finally,
and
were incubated with several hybrids, and the diameter of zone of inhibition was observed to assessment the potential antibacterial properties of the hybrids.
The sol–gel route represents a valuable technique to obtain functional materials, in which organic and inorganic members are closely connected. Herein, four hybrid materials, containing caffeic acid ...entrapped in a silica matrix at 5, 10, 15, and 20 wt.%, were synthesized and characterized through Fourier-Transform Infrared (FT-IR) and Ultraviolet-Visible (UV–Vis) spectroscopy. FT-IR analysis was also performed to evaluate the ability to induce the hydroxyapatite nucleation. Despite some structural changes occurring on the phenol molecular skeleton, hybrid materials showed scavenging properties vs. 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) radical cation (ABTS•+), which was dependent on the tested dose and on the caffeic acid wt.%. The SiO2/caffeic acid materials are proposed as valuable antibacterial agents against Escherichia coli and Enterococcus faecalis.
Collagen-based membranes are class III-medical devices widely used in dental surgical procedures to favour bone regeneration. Here, we aimed to provide biophysical and biochemical data on this type ...of devices to support their optimal use and design/manufacturing. To the purpose, four commercial, non-crosslinked collagen-based-membranes, obtained from various sources (equine tendon, pericardium or cortical bone tissues, and porcine skin), were characterized in vitro. The main chemical, biophysical and biochemical properties, that have significant clinical implications, were evaluated. Membranes showed similar chemical features. They greatly differed in morphology as well as in porosity and density and showed a diverse ranking in relation to these latter two parameters. Samples highly hydrated in physiological medium (swelling-ratio values in the 2.5-6.0 range) and, for some membranes, an anisotropic expansion during hydration was, for the first time, highlighted. Rheological analyses revealed great differences in deformability (150-1500kPa G') also alerting about the marked variation in membrane mechanical behaviour upon hydration. Samples proved diverse sensitivity to collagenase, with the cortical-derived membrane showing the highest stability. Biological studies, using human-bone-derived cells, supported sample ability to allow cell proliferation and to prompt bone regeneration, while no relevant differences among membranes were recorded. Prediction of relative performance based on the findings was discussed. Overall, results represent a first wide panel of chemical/biophysical/biochemical data on collagen-based-membranes that 1) enhances our knowledge of these products, 2) aids their optimal use by providing clinicians with scientific basis for selecting products based on the specific clinical situation and 3) represents a valuable reference for optimizing their manufacturing.
The use of oral iron integration is commonly recommended for the treatment of iron deficiency, nevertheless the diagnosis and treatment of this disease could clearly be improved. The aim of this work ...was the synthesis of therapeutic systems, iron (II) based, by sol-gel method. In an SiO₂ matrix, we embedded different weight percentages of polyethylene glycol (PEG
) and ferrous citrate (Fe(II)C
) for drug delivery applications. Fourier Transform Infrared (FTIR) spectroscopy was used to study the interactions among different components in the hybrid materials. Release kinetics in a simulated body fluid (SBF) were investigated and the amount of Fe
released was detected by Ultraviolet⁻Visible spectroscopy (UV-VIS) after reaction with ortho-phenantroline. Furthermore, the biological characterization was carried out. The bioactivity of the synthesized hybrid materials was evaluated by the formation of a layer of hydroxyapatite on the surface of samples soaked in SBF using FTIR spectroscopy. Finally, also, the potential antibacterial properties of the different materials against two different bacteria,
and
, were investigated.
The need to improve the expectancy and quality of life of subjects affected by disabling pathologies that require the replacement or regeneration of tissues or parts of the body has fueled the ...development of innovative, better-performing materials that are capable of integrating into and being tolerated by body tissues. Materials with these characteristics, i.e., bio-functionality, bio-safety, and biocompatibility, are defined as biomaterials. One of the many methods for producing such materials is the sol–gel technique. This process is mainly used for the preparation of ceramic oxides at low temperatures, through hydrolysis and polycondensation reactions of organometallic compounds within a hydroalcoholic solution. This study is based on a specific type of biomaterial: organic–inorganic hybrids. The aim of this study is to provide an overview of the advantages and disadvantages of the sol–gel technique, as well as describe the preparation and chemical and biological characterization, uses, and future prospects of these biomaterials. In particular, the use of plant drugs as organic components of the hybrid material is the innovation of this manuscript. The biological properties of plant extracts are numerous, and for this reason, they deserve great attention from the scientific community.
Zirconia widely used in biomedical applications has three crystalline forms, but the transformation from tetragonal to monoclinic is a serious problem in the biomedical field. In this regards, silica ...was added to stabilize the tetragonal zirconia phase. In fact, in this study four SiO2/ZrO2 composites with different percentages of zirconia were synthesized with the sol-gel method. The aim of the present study was to check the suitability of these materials as a vector in the adsorption of an active drug. After the sintering process at different temperatures the materials have been chemically and biologically characterized. The interactions between the inorganic matrices and the identification of the different crystalline phases depending on the temperature of the thermal treatment were evaluated by Fourier transform infrared (FTIR) spectroscopy and XRD analysis. Furthermore, the absorption of ampicillin was carried out using UV–Vis. The bioactivity was studied after soaking the materials in simulated body fluid (SBF) for 21 days, by observing the characteristic peaks of hydroxyapatite by FTIR analysis. Finally, after drug absorption the materials were incubated against Escherichia coli in order to evaluate the antibacterial properties and the release of the drug from the different composites.
Fly ash recycling reduces the amount of waste to be treated or disposed in landfills, allowing both to decrease the environmental damage and to save the costs of transport and disposal of waste. ...Systems with different percentages in mass of fly ash (20, 50 and 70 mass%) and the remaining part of pure metakaolin were synthesized. The effect of fly ash on the mechanical and thermal properties of a new geopolymer has been investigated in this paper. Fourier transform infrared spectroscopy has allowed us to verify the bonds formation between the geopolymeric matrix and the fly ash. The consolidation of the materials has been confirmed by pH and conductivity at up to 28 days of hardening. Dynamic mechanical analysis, differential scanning calorimetry and thermogravimetric analysis were performed in order to evaluate the thermo-mechanical performance of this new geopolymer in comparison with its counterpart pure geopolymer.
Simulated synovial fluid (SSF) is a fluid that approximates the biological environment of a human joint because it is based on hyaluronic acid. The soaking of biomedical grade ultra high molecular ...weight polyethylene (UHMWPE) in SSF for longer periods results in ageing of the polymer, hardening the surface, and improving the surface roughness and wettability. This is because SSF progressively penetrates inside the polymer inducing oxidative degradation. Nanocomposite of UHMWPE reinforced with carbon nanofiller (CF) exhibits a higher resistance to the degradation of SSF compared to the control sample (pure UHMWPE).CNF, homogeneously distributed in the polymeric matrix, closes the pores among the grain boundaries of UHMWPE matrix, hindering the SSF insertion within it and its degrading action.
The formation of pro-oxidant species after implantation of biomaterials could be responsible for the failure of the implant itself, because of oxidative stress-induced damage. In this work, the ...SiO₂/polyethylene glycol (PEG)/chlorogenic acid (CGA) hybrids synthesized by the sol⁻gel method with 50 wt% of the polymer and different amounts of CGA (5, 10, 15 and 20 wt%) were studied. The hybrids soaked in simulated body fluid (SBF) showed the formation of hydroxyapatite layers on their surface, suggesting that the hybrids are bioactive. Their radical scavenging capacity towards DPPH
and ABTS
(2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), evaluated at three different doses (0.5, 1 and 2 mg), showed probe- and dose-dependent behavior. In addition, the antioxidant properties of CGA were not affected by the presence of high amounts of the polymer. The in vitro biocompatibility in three cell lines (NIH 3T3, HaCaT and SH-SY5Y) was assessed by using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Apart from SH-SY5Y, the cell viability-expressed as mitochondrial redox activity percentage of cells directly exposed to powders-and morphology was not affected, suggesting that the hybrids have the ability to interfere and act selectively against tumor cells. The antibacterial properties of the different materials against
and
were affected by different amounts of the natural antioxidant component.
Quercetin, whose health‐promoting effects are acclaimed, is entrapped in a silica‐based and silica/polymer hybrid material via sol–gel route, to develop new antioxidant biomaterials for preventing ...the onset of ROS‐related diseases. The materials’ morphology is detected by SEM analysis, whereas the chemical characterization is achieved by spectroscopic and spectrometric techniques. Despite an oxidation reaction in the quercetin structure, DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) and ABTS 2,2′‐azinobis‐(3‐ethylbenzothiazolin‐6‐sulfonic acid) data show that all the materials preserve its antioxidant efficacy. MTT 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide test indicates a mild cytotoxicity in NIH‐3T3, PC12, and U251 cells. Furthermore, materials with the highest quercetin percentage are able to inhibit the H2O2‐induced intracellular ROS production in murine fibroblasts.
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