by Keyword: Drug release

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Enshaei, H., Puiggalí-Jou, A., del Valle, L. J., Turon, P., Saperas, N., Alemán, C., (2021). Nanotheranostic interface based on antibiotic-loaded conducting polymer nanoparticles for real-time monitoring of bacterial growth inhibition Advanced Healthcare Materials

Conducting polymers have been increasingly used as biologically interfacing electrodes for biomedical applications due to their excellent and fast electrochemical response, reversible doping–dedoping characteristics, high stability, easy processability, and biocompatibility. These advantageous properties can be used for the rapid detection and eradication of infections associated to bacterial growth since these are a tremendous burden for individual patients as well as the global healthcare system. Herein, a smart nanotheranostic electroresponsive platform, which consists of chloramphenicol (CAM)-loaded in poly(3,4-ethylendioxythiophene) nanoparticles (PEDOT/CAM NPs) for concurrent release of the antibiotic and real-time monitoring of bacterial growth is presented. PEDOT/CAM NPs, with an antibiotic loading content of 11.9 ± 1.3% w/w, are proved to inhibit the growth of Escherichia coli and Streptococcus sanguinis due to the antibiotic release by cyclic voltammetry. Furthermore, in situ monitoring of bacterial activity is achieved through the electrochemical detection of β-nicotinamide adenine dinucleotide, a redox active specie produced by the microbial metabolism that diffuse to the extracellular medium. According to these results, the proposed nanotheranostic platform has great potential for real-time monitoring of the response of bacteria to the released antibiotic, contributing to the evolution of the personalized medicine.

Keywords: Bacterial detection, Chloramphenicol, Conducting polymers, Drug release, Electrochemical sensors, Electrostimulated release, Polythiophene

Khurana, K., Guillem-Marti, J., Soldera, F., Mücklich, F., Canal, C., Ginebra, M. P., (2020). Injectable calcium phosphate foams for the delivery of Pitavastatin as osteogenic and angiogenic agent Journal of Biomedical Materials Research - Part B Applied Biomaterials 108, (3), 760-770

Apatitic bone cements have been used as a clinical bone substitutes and drug delivery vehicles for therapeutic agents in orthopedic applications. This has led to their combination with different drugs with known ability to foster bone formation. Recent studies have evaluated Simvastatin for its role in enhanced bone regeneration, but its lipophilicity hampers incorporation and release to and from the bone graft. In this study, injectable calcium phosphate foams (i-CPF) based on α-tricalcium phosphate were loaded for the first time with Pitavastatin. The stability of the drug in different conditions relevant to this study, the effect of the drug on the i-CPFs properties, the release profile, and the in vitro biological performance with regard to mineralization and vascularization were investigated. Pitavastatin did not cause any changes in neither the micro nor the macro structure of the i-CPFs, which retained their biomimetic features. PITA-loaded i-CPFs showed a dose-dependent drug release, with early stage release kinetics clearly affected by the evolving microstructure due to the setting of cement. in vitro studies showed dose-dependent enhancement of mineralization and vascularization. Our findings contribute towards the design of controlled release with low drug dosing bone grafts: i-CPFs loaded with PITA as osteogenic and angiogenic agent.

Keywords: Controlled drug release, Endothelial progenitor cells, Mineralization, Rat mesenchymal stem cells, Vascularization

Khurana, Kanupriya, Müller, Frank, Jacobs, Karin, Faidt, Thomas, Neurohr, Jens-Uwe, Grandthyll, Samuel, Mücklich, Frank, Canal, Cristina, Pau Ginebra, Maria, (2018). Plasma polymerized bioceramics for drug delivery: Do surface changes alter biological behaviour? European Polymer Journal 107, 25-33

One of the treatments for recurrent or complicated osteomyelitis is by local antibiotherapy mediated by suitable bone grafts. β–Tricalcium Phosphate (β–TCP) bioceramic is a resorbable bone graft. Its microporosity allows for incorporation of drugs, but a too fast release is often obtained. Complex strategies have been explored to obtain controlled drug release. In this work, plasma polymerization of a biocompatible polymer was investigated on β-TCP. Polyethyleneglycol (PEG)-like polymer coatings of different thickness were deposited on microporous β-TCP loaded with antibiotics. A highly hydrophobic surface was obtained despite the hydrophilicity of the PEG-like layer produced, which was associated to the roughness of the β-TCP substrate. The bioceramics nevertheless retained their suitable biological behavior with regard to human osteoblast cells. The microbiological activity of the antibiotics was preserved, and the coatings reduced the total amount of drug released as a function of the increasing plasma treatment time.

Keywords: Plasma polymerization, β–Tricalcium phosphate, PEG-like polymer, Antibiotics, Drug release, Biocompatibility