A Novel Strategy for Creating an Antibacterial Surface Using a Highly Efficient Electrospray-Based Method for Silica Deposition

Adhesion of bacteria on biomedical implant surfaces is a prerequisite for biofilm formation, which may increase the chances of infection and chronic inflammation. In this study, we employed a novel electrospray-based technique to develop an antibacterial surface by efficiently depositing silica homogeneously onto polyethylene terephthalate (PET) film to achieve hydrophobic and anti-adhesive properties. We evaluated its potential application in inhibiting bacterial adhesion using both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria. These silica-deposited PET surfaces could provide hydrophobic surfaces with a water contact angle greater than 120° as well as increased surface roughness (root mean square roughness value of 82.50 ± 16.22 nm and average roughness value of 65.15 ± 15.26 nm) that could significantly reduce bacterial adhesion by approximately 66.30% and 64.09% for E. coli and S. aureus, respectively, compared with those on plain PET surfaces. Furthermore, we observed that silica-deposited PET surfaces showed no detrimental effects on cell viability in human dermal fibroblasts, as confirmed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide and live/dead assays. Taken together, such approaches that are easy to synthesize, cost effective, and efficient, and could provide innovative strategies for preventing bacterial adhesion on biomedical implant surfaces in the clinical setting.

Biological Characterization of Polymeric Matrix and Graphene Oxide Biocomposites Filaments for Biomedical Implant Applications: A Preliminary Report

Carbon nanostructures application, such as graphene (Gr) and graphene oxide (GO), provides suitable efforts for new material acquirement in biomedical areas. By aiming to combine the unique physicochemical properties of GO to Poly L-lactic acid (PLLA), PLLA-GO filaments were produced and characterized by X-ray diffraction (XRD). The in vivo biocompatibility of these nanocomposites was performed by subcutaneous and intramuscular implantation in adult Wistar rats. Evaluation of the implantation inflammatory response (21 days) and mesenchymal stem cells (MSCs) with PLLA-GO took place in culture for 7 days. Through XRD, new crystallographic planes were formed by mixing GO with PLLA (PLLA-GO). Using macroscopic analysis, GO implanted in the subcutaneous region showed particles’ organization, forming a structure similar to a ribbon, without tissue invasion. Histologically, no tissue architecture changes were observed, and PLLA-GO cell adhesion was demonstrated by scanning electron microscopy (SEM). Finally, PLLA-GO nanocomposites showed promising results due to the in vivo biocompatibility test, which demonstrated effective integration and absence of inflammation after 21 days of implantation. These results indicate the future use of PLLA-GO nanocomposites as a new effort for tissue engineering (TE) application, although further analysis is required to evaluate their proliferative capacity and viability.

Electrochemical and biological behaviour of near β Titanium alloy for biomedical implant applications

Pulsed laser deposition technique (PLD) is one of the methods to coat hydroxyapatite on near beta titanium alloys (Ti-13Nb-13Zr) implants which are used in orthopaedics and dentistry applications. In this study, Hydroxyapatite (HA) ceramics in the form of calcium phosphate (Cap) were deposited on nearβ Titanium alloys (Ti-13Nb-13Zr) by the pulsed laser deposition method. The coated thin film was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM) with Energy dispersive spectroscopy (EDS) and atomic microscopy (AFM). The corrosion studies were carried out coated and uncoated samples using potentiodynamic polarisation studies in simulated body fluid (Hanks’ solution). The bioactivity of the Hap-coated samples on nearβ Titanium alloys was evaluated by immersing them in simulated body fluid (SBF) for nine days. XRD and EDS analysis confirmed the presence of hydroxyapatite. The corrosion studies showed that the treated samples have better corrosion resistance compared to uncoated substrates. The formation of apatite on treated samples revealed the bioactivity of the Hap-coated substrates. HA-coated nearβ Titanium alloys provide higher corrosion protection than substrates, which can be used for biomedical implant applications.

E-shape Metamaterials Embedded Implantable Antenna for ISM-band Biomedical Applications

This paper presents a compact antenna based on two different metamaterial resonators, the E-shape resonators and the interdigital resonators suitable for biomedical implant applications. The proposed antennas operate in the industrial, scientific, and medical (ISM) bands in the frequency band of 2.4–2.5 GHz. The integration of metamaterial (MTM) in the design leading to the reduce size of these antennas and gaining enhancement. The overall size of the proposed antennas is\(8\times 7\times 1.27{\mathbf{m}\mathbf{m}}^{3}\). The implantable antennas contain two layers of the substrate; the lower layer comprises the MTM resonators and the upper, superstrate layer. To order to observe the exposure of electromagnetic energy to human tissues, the specific absorption rates (SARs) of the proposed antennas are also calculated in the layer model. The antennas are designed and simulated by the two software simulators CST and HFSS.