Water-based, surfactant-free cytocompatible nanoparticle-microgel-composite biomaterials – rational design by laser synthesis, processing into fiber pads and impact on cell proliferation

Abstract

Abstract:This work highlights the laser-based aqueous synthesis and processing of nanocomposites, composed of zinc or iron nanoparticles embedded in a N-Vinylcaprolactam microgel matrix, with potential applicability as ion releasing fiber pads for wound healing. An in situ laser process for microgel synthesis is developed and optimized for high embedded nanoparticle yields, evaluating influences of laser repetition rate and monomer concentration. The impact of the nanoparticles on polymerization was increased by embedded zinc oxide nanoparticles, and reduced in the presence of iron oxide. Furthermore, TEM images verified that the nanoparticles were homogeneously embedded into the polymer matrix. The nanoparticle-loaded microgels were thermally stable up to 429°C, which ensures that the composites maintain their integrity after heat sterilization and during rapid prototyping by thermal polymer processing. The general suitability of the hydrogels as active biomaterial for wound healing was assessed in toxicity, cell proliferation and migration assays using human dermal fibroblasts and keratinocytes, where cytocompatibility was verified, while the proliferation was affected by the gel alone as well as the embedded nanoparticles. The hydrogels were processed to suit their use as a biomaterial for wound coverages via electrospinning resulting in a centimeter scale fully cytocompatible fiber pad with the nanoparticle-filled microgel capsules supported on the fiber's surface.

Two Birds with One Stone: Spontaneous Size Separation and Growth Inhibition of Femtosecond Laser-Generated Surfactant-Free Metallic Nanoparticles via ex Situ SU-8 Functionalization

“…After SU-8 degradation at 700 °C, 22 wt % pyrolysate is residual, which is close to 25 wt % residue of SU-8 pyrolysate reported elsewhere. 65 Deduced from the TGA curve, 66 the Ag NP content is estimated to be 4 wt %. Epoxide rings are good synthetic intermediates; therefore, it is speculated that the epoxy groups of SU-8 should be first converted into hydroxyl groups and then act as initiator sites for the free-radical polymerization of SU-8 photoresist.…”

Matrix-specific mechanism of Fe ion release from laser-generated 3D-printable nanoparticle-polymer composites and their protein adsorption properties

“…With high power laser systems, the productivity of metal nanoparticles can reach 4 g h −1 in water [39]. However, significantly reduced values are commonly found in organic solvents [36] and few works reported the NP productivity in polymer solutions [40].…”

Iron Nanoparticle Composite Hydrogels for Studying Effects of Iron Ion Release on Red Blood Cell In Vitro Production

“…27,28 When PLAL is carried out directly in a monomer solution (in situ), the generated nanoparticles immediately interact with the monomers, which stabilize the particles and enable monodisperse particles with mean diameters <10 nm. 29 In a consecutive step, the monomers can be subjected to polymerization, for example, by UV-light irradiation. For hydrogel nanocomposite synthesis, even this step is obsolete, as the nanoparticles are directly synthesized by PLAL in the aqueous hydrogel solution.…”

“…In a consecutive step, the nanoparticles are embedded into the polymer matrix, which often requires matrix-coupling reagents . As an alternative approach, pulsed laser ablation in liquids (PLAL), for the fabrication of the corresponding nanocomposites is highly promising. , This method has been intensively studied and is based on the irradiation of bulk metal targets by pulsed lasers in liquid yielding colloidal nanoparticles. , When PLAL is carried out directly in a monomer solution ( in situ ), the generated nanoparticles immediately interact with the monomers, which stabilize the particles and enable monodisperse particles with mean diameters <10 nm . In a consecutive step, the monomers can be subjected to polymerization, for example, by UV-light irradiation.…”