Fe70Pd30 system possesses magnetic shape memory-effect, which can be used in medicine purposes for triggering the drugs, for example. We report on successful direct electrochemical synthesis of Fe-Pd nanotubes. The tubes are ferromagnetic with high Ms=170 emu/g. For the application in medicine, the nanotubes were functionalized with the model drug paracetamol. The proposed type of release, with an initial burst and a slower release of the remaining drug, could be suitable for applications where a fast action is required, which then has to be maintained for a certain time period.
COBISS.SI-ID: 25576999
Mass transport and kinetic parameters of the Fe-Pd electrodeposition were evaluated and plating conditions for achieving the composition of Fe70 at%, important for magnetic shape memory effect were proposed.
COBISS.SI-ID: 27452967
The electrochemical study of the Fe-Pd electrolyte showed that the electrodeposition of Fe-Pd alloy behaves differently than the deposition of single metal. It was found out that CV cycling is necessary in order to understand real-time behaviour during the electrodeposition, since the conditions in the electrodeposition change as soon as the first layers of Fe or Pd are deposited. Deposition of Fe from Fe-Pd electrolyte was found to start at –0.6 V (more than 500 mV more positive in comparison to Fe from single electrolyte). This can be attributed to the catalytic behaviour of Pd-layer which deposited prior to Fe. These results contribute to the understanding of the binary alloy Fe-Pd deposition behavior which is of importance for further tailoring of the composition and the final magnetic properties.
COBISS.SI-ID: 28199975
With the advancement of drug delivery systems based on mesoporous silica nanoparticles (MSNs), a simple and efficient method regulating the drug release kinetics is needed. We developed redox-responsive release systems with three levels of hindrance around the disulfide bond. A model drug (rhodamine B dye) was loaded into MSNs' mesoporous voids. The pore opening was capped with beta-cyclodextrin in order to prevent leakage of drug. Indeed, in absence of a reducing agent the systems exhibited little leakage, while the addition of dithiothreitol cleaved the disulfide bonds and enabled the release of cargo. The release rate and the amount of released dye were tuned by the level of hindrance around disulfide bonds, with the increased hindrance causing a decrease in the release rate as well as in the amount of released drug. Thus, we demonstrated the ability of the present mesoporous systems to intrinsically control the release rate and the amount of the released cargo by only minor structural variations. Furthermore, an in vivo experiment on zebrafish confirmed that the present model delivery system is nonteratogenic.
COBISS.SI-ID: 26701351
To elucidate the importance of the size of capping agents in stimulus-induced release systems from mesoporous silica nanoparticles (MSNs), the effectiveness of poly(propylene imine) dendrimers in controlling the model drug release was studied. MCM-41-type MSNs were synthesized and characterized. Fluorescent compounds (fluorescein disodium salt and carboxyfluorescein) were loaded in the porous structure of the MSNs and entrapped in the silica matrix with the dendrimers of generations I through V by anchoring dendrimers on the MSN surface through disulfide bonds. Stimulus-induced release of the cargo was studied in the presence of dithiothreitol (DTT). Dendrimers of generations I and II were found to be more effective in model drug retention and subsequent release than higher generations. Moreover, MSNs modified with larger amounts of dendrimers lowered the cargo release in the presence of DTT. These findings are of importance for optimizing drug delivery systems based on responsive MSNs as they enable tuning of the amount of the released cargo by choosing the capping agent of appropriate size.
COBISS.SI-ID: 5234714