The concentrations of the redox pair hydrogen peroxide (HO) and oxygen (O) can promote or decelerate the progression and duration of the wound healing process. Although HO can reach critically high concentrations and prohibit healing, a sufficient O inflow to the wound is commonly desired. Herein, we describe the fabrication and use of a membrane that can contemptuously decrease HO and increase O levels. Therefore, hematite nanozyme particles were integrated into electrospun and cross-linked poly(vinyl alcohol) membranes. Within the dual-compound membrane, the polymeric mesh provides a porous scaffold with high water permeability and the nanozymes act as a catalyst with catalase-like activity that can efficiently convert HO into O, as shown by a catalase assay. When comparing the growth of fibroblasts at an HO concentration of 50 μM, the growth was largely enhanced when applying the nanozyme dressing. Thus, application of the nanozyme dressing can significantly reduce the harmful effect of higher HO concentrations. The described catalytic membranes could be used in the future to provide an improved environment for cell proliferation in wounds and thus applied as advanced wound healing dressings.

Rational design of nanocarriers for drug delivery approaches requires an unbiased knowledge of uptake mechanisms and intracellular trafficking pathways. Here we dissected these processes using a quantitative proteomics approach. We isolated intracellular vesicles containing superparamagnetic iron oxide polystyrene nanoparticles and analyzed their protein composition by label-free quantitative mass spectrometry. The proteomic snapshot of organelle marker proteins revealed that an atypical macropinocytic-like mechanism mediated the entry of nanoparticles. We show that the entry mechanism is controlled by actin reorganization, atypical macropinocytic signaling, and ADP-ribosylation factor 1. Additionally, our proteomics data demonstrated a central role for multivesicular bodies and multilamellar lysosomes in trafficking and final nanoparticle storage. This was confirmed by confocal microscopy and cryo-TEM measurements. By quantitatively analyzing the protein composition of nanoparticle-containing vesicles, our study clearly defines the routes of nanoparticle entry, intracellular trafficking, and the proteomic milieu of a nanoparticle-containing vesicle.

From particles to fibers: Nanofibers with different morphologies and periodicities can be fabricated by supraparticular assembly of magnetic spherical nanoparticles. A linear sintering process is used to merge the assembled colloids together. The structure of the obtained fibers is controlled by the process parameters and the morphology of the spherical colloidal building blocks.

A three-component nanocapsule-based system allows monitoring the health cycle of coatings via autonomous visual highlighting of damages and reversible erasing through healing.