Synergistic effect of κ-carrageenan and gelatin blends towards adipose tissue engineering.

The current paper focuses on the functionalization of κ-carrageenan and gelatin as extracellular matrix polysaccharide and protein mimic respectively to produce hydrogel films for adipose tissue engineering. More specifically, κ-carrageenan as well as gelatin have been functionalized with methacrylate and methacrylamide moieties respectively to enable subsequent UV-induced crosslinking in the presence of a photo-initiator. The gel fraction, the mass swelling ratio and the mechanical properties of both the one-component hydrogels and the protein/polysaccharide blends have been evaluated. The mechanical and swelling properties of the blends could be tuned by varying the hydrogel composition as well as the crosslinking method applied. The in vitro biocompatibility assays indicated a significantly higher cell viability of adipose tissue-derived mesenchymal stem cells seeded onto the blends as compared to the one-component hydrogels. The results show that the blends of gelatin and κ-carrageenan clearly outperform the one-component hydrogels in terms of adipose tissue engineering potential.

Soft tissue fillers for adipose tissue regeneration: From hydrogel development toward clinical applications.

There is a clear and urgent clinical need to develop soft tissue fillers that outperform the materials currently used for adipose tissue reconstruction. Recently, extensive research has been performed within this field of adipose tissue engineering as the commercially available products and the currently existing techniques are concomitant with several disadvantages. Commercial products are highly expensive and associated with an imposing need for repeated injections. Lipofilling or free fat transfer has an unpredictable outcome with respect to cell survival and potential resorption of the fat grafts. Therefore, researchers are predominantly investigating two challenging adipose tissue engineering strategies: in situ injectable materials and porous 3D printed scaffolds. The present work provides an overview of current research encompassing synthetic, biopolymer-based and extracellular matrix-derived materials with a clear focus on emerging fabrication technologies and developments realized throughout the last decade. Moreover, clinical relevance of the most promising materials will be discussed, together with potential concerns associated with their application in the clinic.

Fabrication and characterization of microlens arrays using a cantilever-based spotter.

We present a quantitative study on the fabrication of microlenses using a low-cost polymer dispending technique. Our method is based on the use of a silicon micro-cantilever robotized spotter system. We first give a detailed description of the technique. In a second part, the fabricated microlenses are fully characterized by means of SEM (Scanning Electron Microscope), AFM (Atomic Force Microscopy) non contact optical profilometry and Mach-Zehnder interferometry. Diameters in the range [25-130mum] are obtained with an average surface roughness of 2.02nm. Curvature radii, focal lengths as well as aberrations are also measured for the first time: the fabricated microlenses present focal lengths in the range [55-181mum] and exhibit high optical quality only limited by diffraction behaviour with RMS aberration lower than lambda/14.

Sub-second liquid chromatographic separations by means of shear-driven chromatography.

Utilizing the concept of shear-driven chromatography, we have been able to realize reversed-phase LC separations in flat rectangular nano-channels coated with a C8 monolayer and being as thin as 100 nm. At this scale, the separation kinetics are strongly enhanced, as is witnessed by the extremely short time (< 0.1 s) needed to separate a mixture of coumarin dyes. The observed plate numbers are still relatively small, because the experiments were conducted in ultra-short columns (< or = 1 mm) and under injection band width-limiting conditions.