Laser-generated bioactive hydrogels as ion-release systems for burn wound therapy

Abstract

Here, we investigated the fabrication of bioactive metal nanoparticle-loaded hydrogels, their immobilization into non-woven electrospun microfibers and their biocompatibility. For this purpose, zinc and iron nanoparticles were synthesized by pulsed laser ablation of corresponding metal targets in an aqueous monomer solution. This solution was simultaneously and consecutively polymerized yielding loaded hydrogels. The laser ablation process was investigated concerning the influence of different laser parameters on the ablation efficiency, including the determination of the cavitation bubble dynamics. The in situ fabrication of stable nanoparticle polymer composites, namely nanoparticle-loaded microgels, using the laser ablation method was established. The microgels described were immobilized by electrospinning in order to achieve surface modified microfibers. Electron microscopy and inductively coupled plasma mass spectrometry were used to characterize the suitability of the zinc nanoparticle-loaded microgels immobilized in microfibers for a zinc ion release over a period of five days without release of the nanoparticles. The amounts of ions and the release rates were regulated by variations of the composites used for the electrospinning process. Parallely, in vitro indirect biocompatibility and bioresponse tests showed no cytotoxicity not from the hydrogels nor from the microfibers. Cell proliferation was increased for both systems separately and for their combination. The ion releases of the iron and zinc nanoparticle-loaded microgels were too low to induce any subsequent effect on cell culture.