Amylase inhibitors, also known as starch blockers, contain substances that prevent dietary starches from being absorbed by the body via inhibiting breakdown of complex sugars to simpler ones. In this sense, these materials are projected as having potential applications in diabetes control. In this context, we report on zinc oxide nanoparticles as possible alpha-amylase inhibitors. Zinc oxide nanoparticles have been synthesized using soft-chemistry approach and 1-thioglycerol was used as a surfactant to yield polycrystalline nanoparticles of size ∼18 nm, stabilized in wurtzite structure. Conjugation study and structural characterization have been done using x-ray diffraction technique, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and transmission electron microscopy. Cytotoxicity studies on human fibrosarcoma (HT-1080) and skin carcinoma (A-431) cell lines as well as mouse primary fibroblast cells demonstrate that up to a dose of 20 μg/ml, ZnO nanoparticles are nontoxic to the cells. We report for the first time the alpha-amylase inhibitory activity of ZnO nanoparticles wherein an optimum dose of 20 μg/ml was sufficient to exhibit 49% glucose inhibition at neutral pH and 35 °C temperature. This inhibitory activity was similar to that obtained with acarbose (a standard alpha-amylase inhibitor), thereby projecting ZnO nanoparticles as novel alpha-amylase inhibitors.

Electrospinning is a long-known polymer processing technique that has received more interest and attention in recent years due to its versatility and potential use in the field of biomedical research. The fabrication of three-dimensional (3D) electrospun matrices for drug delivery and tissue engineering is of particular interest. In the present study, we identified optimal conditions to generate novel electrospun polymeric scaffolds composed of poly-d/l-lactide and poly-l-lactide in the ratio 50:50. Scanning electron microscopic analyses revealed that the generated poly(d/l-lactide-co-l-lactide) electrospun hybrid microfibers possessed a unique porous high surface area mimicking native extracellular matrix (ECM). To assess cytocompatibility, we isolated dermal fibroblasts from human skin biopsies. After 5 days of in vitro culture, the fibroblasts adhered, migrated and proliferated on the newly created 3D scaffolds. Our data demonstrate the applicability of electrospun poly(d/l-lactide-co-l-lactide) scaffolds to serve as substrates for regenerative medicine applications with special focus on skin tissue engineering.

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Radiopaque biodegradable polymers have been synthesized by ring-opening polymerization of L/DL-lactide and caprolactone with the iodine-containing starter molecule 2,2-bis(hydroxymethyl)propane-1,3-diyl bis(2,3,5-triiodobenzoate) followed by chain elongation with a diacid chloride or diisocyanates. The resulting polyesters and poly(ester-urethanes) exhibited a radiopacity of 60−124% relative to an aluminium sample of the same thickness. The polymers were processed into monofilament fibres by melt-spinning and into fibre meshes by electrospinning. All polymers were biodegradable in simulated body fluid medium under in vitro conditions and showed an excellent in vitro cytocompatibility even after several months of hydrolytic degradation. A current drawback is the relatively low tensile strength of the polymer monofilaments, which needs to be improved for applications as textile structures. Nevertheless, the new radiopaque and biodegradable polymers are promising candidates in fields of application where radiopacity of implants is an important parameter.

Polyester knitted fabrics have been equipped with antibacterial properties by coating with aqueous suspensions of zinc oxide (ZnO) with different particle diameters. It can be shown that the antibacterial efficacy against Staphylococcus aureus and Klebsiella pneumonia and the permanence of the coating after defined washing cycles depends on the composition of the ZnO dispersion. To improve the wettability of the textile, the combustion chemical vapor deposition (CCVD) is used to generate a hydrophilic nano layer of a hydroxyl terminated silicon network on the surface of the textiles. The comparison of CCVD-treated and untreated polyester samples does not show differences in the antibacterial activity. The influence of the coating in terms of amount and particle size of ZnO on the viability and proliferation of 3T3 mouse fibroblast cells is examined. A particle content of a maximum of 20 µg ZnO/cm 2 is found to be cytocompatible for coating of textiles.