Publications

Local cancer treatment by in situ injections of thermo-responsive hydrogels (HG) offers several advantages over conventional systemic anti-cancer treatments. In this work, a biodegradable and multicompartmental HG composed of N-isopropylacrylamide, cellulose, citric acid, and ceric ammonium nitrate was developed for the controlled release of hydrophilic (doxorubicin) and hydrophobic (niclosamide) drugs. The formulation presented ideal properties regarding thermo-responsiveness, rheological behavior, drug release profile, biocompatibility, and biological activity in colon and ovarian cancer cells. Cellulose was found to retard drugs release rate, being only 4 % of doxorubicin and 30 % of niclosamide released after 1 week. This low release was sufficient to cause cell death in both cell lines. Moreover, HG demonstrated a proper injectability, in situ prevalence, and safety profile in vivo. Overall, the HG properties, together with its natural and eco-friendly composition, create a safe and efficient platform for the local treatment of non-resectable tumors or tumors requiring pre-surgical adjuvant therapy.

JTD Keywords: biodegradable, cellulose, controlled-release formulation, drug delivery systems, hydrogel, thermo-responsiveness, Ammonium-nitrate, Biodegradable, Cancer treatment, Cellulose, Controlled-release formulation, Delivery, Drug delivery systems, Hydrogel, Reduce, Thermo-responsiveness

Atmospheric pressure plasma jets have been shown to impact several cancer cell lines, both in vitro and in vivo. These effects are based on the biochemistry of the reactive oxygen and nitrogen species generated by plasmas in physiological liquids, referred to as plasma-conditioned liquids. Plasma-conditioned media are efficient in the generation of reactive species, inducing selective cancer cell death. However, the concentration of reactive species generated by plasma in the cell culture media of different cell types can be highly variable, complicating the ability to draw precise conclusions due to the differential sensitivity of different cells to reactive species. Here, we compared the effects of direct and indirect plasma treatment on non-malignant bone cells (hOBs and hMSCs) and bone cancer cells (SaOs-2s and MG63s) by treating the cells directly or exposing them to previously treated cell culture medium. Biological effects were correlated with the concentrations of reactive species generated in the liquid. A linear increase in reactive species in the cell culture medium was observed with increased plasma treatment time independent of the volume treated. Values up to 700 µM for H2O2 and 140 µM of NO2− were attained in 2 mL after 15 min of plasma treatment in AdvDMEM cell culture media. Selectivity towards bone cancer cells was observed after both direct and indirect plasma treatments, leading to a decrease in bone cancer cell viability at 72 h to 30% for the longest plasma treatment times while maintaining the survival of non-malignant cells. Therefore, plasma-conditioned media may represent the basis for a potentially novel non-invasive technique for bone cancer therapy.

JTD Keywords: expression, in-vitro, jet, mechanisms, nitrate, nitrite, osteosarcoma cells, reactive oxygen, Cold atmospheric plasma

Here we have developed a simple method for the fabrication of disposable implantable all-solid-state ion-selective electrodes (ISE) in an array format without using complex fabrication equipment or clean room facilities. The electrodes were designed in a needle shape instead of planar electrodes for a full contact with the tissue. The needle-shape platform comprises 12 metallic pins which were functionalized with conductive inks and ISE membranes. The modified microelectrodes were characterized with cyclic voltammetry, scanning electron microscope (SEM), and optical interferometry. The surface area and roughness factor of each microelectrode were determined and reproducible values were obtained for all the microelectrodes on the array. In this work, the microelectrodes were modified with membranes for the detection of pH and nitrate ions to prove the reliability of the fabricated sensor array platform adapted to an endoscope.

JTD Keywords: Chemical sensors, Cyclic voltammetry, Electrochemistry, Endoscopy, Fabrication, Implants (surgical), Microelectrodes, Needles, Nitrates, Scanning electron microscopy, Biomedicine, Fabricated sensors, Fabrication equipment, Implantable devices, Implantable sensors, Optical interferometry, Planar electrode, Roughness factor, Ion selective electrodes