The challenge of mimicking the extracellular matrix with artificial scaffolds that are able to reduce immunoresponse is still unmet. Recent findings have shown that mesenchymal stem cells (MSC) infiltrating into the implanted scaffold have effects on the implant integration by improving the healing process. Toward this aim, a novel polyamidoamine-based nanocomposite hydrogel is synthesized, cross-linked with porous nanomaterials (i.e., mesoporous silica nanoparticles), able to release chemokine proteins. A comprehensive viscoelasticity study confirms that the hydrogel provides optimal structural support for MSC infiltration and proliferation. The efficiency of this hydrogel, containing the chemoattractant stromal cell-derived factor 1α (SDF-1α), in promoting MSC migration in vitro is demonstrated. Finally, subcutaneous implantation of SDF-1α-releasing hydrogels in mice results in a modulation of the inflammatory reaction. Overall, the proposed SDF-1α-nanocomposite hydrogel proves to have potential for applications in tissue engineering.

One of the major problems related to the use of dyes in industrial applications is their elimination from the water or soil and eventually their recovery and reutilization. In this context, a new biocompatible material, previously considered suitable for biomedical applications, is presented for the first time, as an innovative adsorbent material for wastewater treatment. A polyamidoamine‐based hydrogel, prepared by Michael‐type polyaddition in water, is used for efficiently adsorbing two anionic toxic textile dyes from aqueous solutions. Several parameters affecting the adsorption process, such as the pH of solutions containing dyes, the amount of hydrogel and dyes, and the effect of temperature, are investigated. Moreover, the hydrogel dehydration and swollen conditions by using dye water solution are studied by Thermo‐Gravimetry (TG) and Differential Scanning Calorimetry (DSC) analyses, finding that the dehydration temperature plays a relevant role in determining the subsequent adsorbing behavior. The material characterization shows that the adsorption process can be attributed to a combination of electrostatic attraction and intermolecular interactions between hydrogel functional groups and the dye molecules. Visible absorption spectroscopy and Fourier Transform InfraRed‐Attenuated Total Reflectance (FTIR‐ATR) support the findings. The kinetics of the dye adsorption process are also evaluated, together with the adsorption isotherms.

An emerging field regarding N^C^N terdentate Pt(II) complexes is their application as luminescent labels for bio-imaging. In fact, phosphorescent Pt complexes possess many advantages such as a wide emission color tunability, a better stability towards photo-and chemical degradation, a very large Stokes shift, and long-lived luminescent excited states with lifetimes typically two to three orders of magnitude longer than those of classic organic fluorophores. Here, we describe the synthesis and photophysical characterization of three new neutral N^C^N terdentate cyclometallated Pt complexes as long-lived bio-imaging probes. The novel molecular probes bear hydrophilic (oligo-)ethyleneglycol chains of various lengths to increase their water solubility and bio-compatibility and to impart amphiphilic nature to the molecules.The complexes are characterized by a high cell permeability and a low cytotoxicity, with an internalization kinetics that depends on both the length of the ethyleneglycol chain and the ancillary ligand.

Biocompatible soft materials have recently found applications in interventional endoscopy to facilitate resection of mucosal tumors. When neoplastic lesions are in organs that can be easily damaged by perforation, such as stomach, intestine and esophagus, the formation of a submucosal fluid cushion (SFC) is needed to lift the tumor from the underlying muscle during the resection of neoplasias. Such procedure is called endoscopic submucosal dissection (ESD). We describe an injectable, biodegradable, hybrid hydrogel able to form a SFC and to facilitate ESD. The hydrogel, based on polyamidoamines, contains breakable silica nanocapsules covalently bound to its network, and able to release biomolecules. To promote degradation, the hydrogel is composed of cleavable disulfide moieties that are reduced by the cells through secretion of glutathione. The same 3 stimulus triggers the breaking of the silica nanocapsules; therefore, the entire hybrid material can be completely degraded and its decomposition depends entirely on the presence of cells. Interestingly the hydrogel precursor solution showed rapid gelation when injected in vivo and afforded a long-lasting high mucosal elevation, keeping the cushion volume constant during the dissection. This novel material can provide a solution to ESD limitations and promote healing of tissues after surgery

Bas-Rhin. LDC especially acknowledges AXA Research funds. PHS and SVA acknowledge the Max Planck Society for generous funding. The authors thank Pengkun Chen for nitrogen adsorption and XPS measurements, Jeannette Steffen for ICP-AES measurements and Heike Runge for SEM assistance. 2 TOC Bottom-up synthesis of flat, disc-shaped mesoporous silica nanoparticles, Nanodiscs (NDs), and their delivery applications are reported. The NDs can be readily internalized by cells or assembled in ordered monolayers, promptly releasing their payload both once internalized or in contact with cells adhering to their flat surface. The initial biological investigations underscore the potential these particles hold for intracellular and surface-mediated delivery applications, representing a significant addition to the biomedical MSNs toolbox.

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L. De Cola and co‐workers report a nanocomposite hydrogel able to induce in vitro chemotaxis of stem cells on page 4881. The cover image shows a nanocomposite hydrogel containing mesoporous silica nanoparticles integrated into the polymeric network. The controlled release of SDF‐1α from the hydrogel induced the chemotaxis of stem cells, while the optimal mechanical properties enhanced stem cells proliferation. These attractive properties together with the low inflammatory response in vivo make this hydrogel a promising material for tissue engineering applications.