Publications

Prostate cancer remains one of the leading causes of cancer-related mortality. Although there were advances in cancer therapy, there is a need for advanced drug delivery strategies to improve the spatiotemporal control of therapeutic action. Here, we developed conductive, redox-responsive hybrid sponges based on glutathione-extended waterborne polyurethane (WPU-GSSG) and the electroactive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) for dual-stimuli-triggered release of anticancer peptide in locoregional tumor therapy. WPU/PEDOT porous scaffolds presented lightweight and mechanically resilient structures with homogeneous loading of the pentapeptide Cys-Arg-N-methyl-Glu-Lys-Ala (CR(NMe)EKA). PEDOT incorporation significantly enhanced the electrochemical properties of the sponges, providing reversible redox activity, reduced impedance, and near-ideal capacitive behavior. The sponges supported cell adhesion and high cell viability within the three-dimensional architecture. In vitro release studies demonstrated that peptide delivery is regulated by a synergistic combination of redox and electrical stimuli. A mimetic tumor microenvironment accelerated peptide release relative to physiological conditions. Electrostimulation (+0.5 V chronoamperometry) further enhanced release kinetics, and the combined application of redox and electrical triggers enabled peptide release of up to similar to 94%, demonstrating tunable stimulus-responsive delivery. Functional assays on cancer cells supported the therapeutic potential of this platform. While WPU alone was fully cytocompatible and PEDOT-containing sponges exhibited moderate electrostimulation-dependent effects, CR(NMe)EKA-loaded conductive sponges induced a pronounced reduction in cancer cell viability under electrostimulation, decreasing survival to similar to 20%. Although further in vivo validation is required, these findings highlight the potential of multifunctional WPU/PEDOT sponges for localized, stimuli-responsive peptide delivery.

JTD Keywords: Cancer, Cell-line, Citrate transport, Design, Electrostimulation, Locoregional drugdelivery, Nanoparticle, Pedot, Ph, Polyurethane, Porosity, Prostate cancer, Redox, Scaffolds

Bioelectrical cues are essential for cardiac function and regeneration, yet current electrostimulation strategies rely on invasive electrodes that limit spatial control and clinical translation. Here, we report magnetoelectric nanocomposite hydrogels that combine core-shell CoFe2O4@BiFeO3 magnetoelectric nanoparticles (ME NPs) with a photo-cross-linked methacrylated gelatin (GelMA) network, enabling wireless electroactivity through externally applied magnetic fields within a soft, biomimetic three-dimensional scaffold. Structural and physicochemical analyses confirmed the successful synthesis of crystalline core-shell ME NPs with strong interfacial coupling, as demonstrated by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and magnetic hysteresis measurements showing exchange bias effects. Homogeneous incorporation of ME NPs within GelMA produced highly porous and interconnected hydrogels, as revealed by scanning electron microscopy and microcomputed tomography. The presence of nanoparticles reduced equilibrium swelling and refined pore architecture, suggesting increased effective cross-linking density and nanoparticle-polymer interactions. Mechanical testing showed soft elastomeric behavior with compressive moduli compatible with cardiac tissue. Under dynamic magnetic stimulation, magnetoelectric hydrogels significantly enhanced cardiac cell viability, proliferation, and morphological organization compared with pristine GelMA controls. After 10 days, the metabolic activity of cells cultured on GelMA-ME NP hydrogels under stimulation was approximately 3-fold higher than that of unstimulated GelMA. These results demonstrate that magnetoelectric hydrogels provide an effective platform for wireless electrostimulation, offering promising opportunities for cardiac tissue engineering and implantable bioelectronic therapies without wired electrodes.

JTD Keywords: Cardiac tissue engineering, Core-shell nanoparticles, Fields, Gelma hydrogels, Magnetoelectric nanocomposites, Tissue, Wireless electrostimulation

Very recently, the controlled release of dopamine (DA), a neurotransmitter whose deficiency is associated with Parkinson's disease, has been postulated as a good alternative to the oral administration of levodopa (L-Dopa), a dopamine precursor, to combat the effects of said disease. However, this is still a very little explored field and there are very few carriers that are capable of releasing DA, a small and water-soluble molecule, in an efficient and controlled manner. In this work, we report a carrier based on a conductive hydrogel capable of loading DA and releasing it progressively and efficiently (100 % release) in a period of five days by applying small electrical stimuli (-0.4 V) daily for a short time (1 min). The hydrogel (CMC/PEDOT), which is electrically active, has been prepared from sodium carboxymethylcellulose and poly(3,4-ethylenedioxythiophene) microparticles, using citric acid as a cross-linking agent. Furthermore, the results have shown that when relatively hydrophobic small molecules, such as chloramphenicol, are loaded, the electrostimulated release is significantly less efficient, demonstrating the usefulness of CMC/PEDOT as a carrier for neurotransmitters.

JTD Keywords: Amines, Carboxymethyl cellulose, Carboxymethylcellulose, Conducting hydrogels, Conducting polymers, Controlled release, Crosslinking, Dopamine, Drug-delivery system, Electrostimulation, Hydrogels, Joining, Levodopa, Loading, Molecules, Neurophysiology, Neurotransmitter release, Neurotransmitters release, Oral administration, Parkinson's disease, Parkinsons-disease, Poly(3,4-ethylenedioxythiophene), Release, Sodium, Transport, Water-soluble molecule

Innovative insulin delivery systems contemplate combining multi-pharmacokinetic profiles for glycemic control. Two device configurations have been designed for the controlled release of insulin using the same chemical compounds. The first insulin delivery system, which displays a rapid release response that, in addition, is enhanced on a short time scale by electrical stimulation, consists on an insulin layer sandwiched between a conducting poly(3,4-ethylenedioxythiophene) (PEDOT) film and a poly-gamma-glutamic acid (gamma-PGA) hydrogel. The second system is constituted by gamma-PGA hydrogel loaded with insulin and PEDOT nanoparticles by in situ gelation. In this case, the insulin release, which only starts after the degradation of the hydrogel over time (i.e. on a long time scale), is slow and sustained. The combination of an on-demand and fast release profile with a sustained and slow profile, which act on different time scales, would result in a very efficient regulation of diabetes therapy in comparison to current systems, allowing to control both fast and sustained glycemic events. Considering that the two systems developed in this work are based on the same chemical components, future work will be focused on the combination of the two kinetic profiles by re-engineering a unique insulin release device using gamma-PGA, PEDOT and insulin.

JTD Keywords: Conducting polymer, Constant, Diabetes, Diabetes-mellitus, Drug-delivery, Electrodes, Electrostimulation, Glucose-responsive hydrogels, Hydrogel, Molecular dynamics, Molecular-dynamics, Nanogels, Nanoparticles, Poly(3,4-ethylenedioxythiophene), Risk

We describe a multi-tasking flexible system that is able to release a wide spectrum antibiotic (levofloxacin, LVX) under electrostimulation and act as a pH sensor for detecting bacterial infections. Combining anodic polymer-ization with plasma polymerization processes we engineered dual pH-and electro-responsive polymeric systems. Particularly, the manufactured devices consisted on a layer of poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PHEDOT) loaded with the LVX antibiotic and coated with a plasma polymer layer of poly(acrylic acid) (PAA). The PHEDOT acted as conductive and electro-responsive agent, while the PAA provided pH responsiveness, changing from a compact globular conformation in acid environments to an expanded open coil conformation in alkaline environments. The assembly between the PHEDOT layer and the PAA coating affected the electro-chemical response of the former, becoming dependent on the pH detected by the latter. The conformational change experienced by the PAA layer as a function of the pH and the redox properties of PHEDOT were leveraged for the electrochemical detection of bacteria growth and for regulating the release of the LVX antibiotic, respectively. The effectiveness of the system as a stimulus-responsive antibiotic carrier and pH sensor was also investigated on strains of Escherichia coli and Streptococcus salivarius.

JTD Keywords: Conducting polymer, Delivery, Drug delivery, Electrostimulation, Levofloxacin, Ph sensor, Plasma, Poly(acrylic acid), Selective detection