Author Correction: Defined Geldrop Cultures Maintain Neural Precursor Cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Defined Geldrop Cultures Maintain Neural Precursor Cells.

Distinct micro-environmental properties have been reported to be essential for maintenance of neural precursor cells (NPCs) within the adult brain. Due to high complexity and technical limitations, the natural niche can barely be studied systematically in vivo. By reconstituting selected environmental properties (adhesiveness, proteolytic degradability, and elasticity) in geldrop cultures, we show that NPCs can be maintained stably at high density over an extended period of time (up to 8 days).

Defined polymer-peptide conjugates to form cell-instructive starPEG-heparin matrices in situ.

Poly(ethylene glycol)-peptide- and glycosaminoglycan-peptide conjugates obtained by a regio-selective amino acid protection strategy are converted into cell-instructive hydrogel matrices capable of inducing morphogenesis in embedded human vascular endothelial cells and dorsal root ganglia.

Quantifying the effect of covalently immobilized enzymes on biofilm formation by atomic force microscopy-based single-cell force spectroscopy.

A novel atomic force microscopy-based single-cell force spectroscopy assay to quantify the adhesion of bacterial cells to surfaces was developed. The assay was applied to quantify the effect of two biofilm-degrading enzymes, the protease Subtilisin A and glycoside hydrolase cellulase, on the attachment of the biofilm-forming bacterial strain Cobetia marina. Insights on the mechanism of the initial adhesion and on the nature of the adhesion-mediating molecules were gained.

A novel, biased-like SDF-1 derivative acts synergistically with starPEG-based heparin hydrogels and improves eEPC migration in vitro.

The CXC chemokine stromal cell-derived factor-1α (SDF-1α, CXCL12) has been proven to recruit CXCR4 positive stem and progenitor cells of different sources to defected heart sites, with significant clinical benefits. However, the rapid proteolytic inactivation by inflammation-related proteases, inaccurate drug delivery or inappropriate local concentrations belong to the largest disadvantages for feasible application. Herein, we present a switchable, biased-like SDF-1α variant, AAV-[S4V]-SDF-1α, whose distinct activity is coupled to the inflammation-associated presence of dipeptidylpeptidase-4 (DPP-4), which cleaves an alanine-alanine dipeptide from the precursor.