Water Bound to Gelatin as Shown by Molecular Structure Studies

Triethyleneglycol dimethacrylate addition improves the 3D-printability and construct properties of a GelMA-nHA composite system towards tissue engineering applications

In tissue engineering, there is a growing interest in the development of 3D printable bone tissue-inspired nanocomposites. However, most such nanocomposites have poor mechanical properties, owing to poor dispersion of the mineral phase (e.g. nano-hydroxyapatite, nHA) within the organic phase (e.g. methacrylated gelatin, GelMA) and low volume fractions of each phase. Triethyleneglycol dimethacrylate (TEGDMA) is commonly added to dental resin-based composites to improve the properties of the dental resin. Here, the effects of substituting a portion of the water phase in a GelMA-nHA composite with TEGDMA were evaluated. TEGDMA improved the dispersion of nHA within the highly-concentrated GelMA-based composite ink, as well as increased the ink's shear yield strength and reduced the critical energy for ink cure. As a result, the printability of the composite ink was greatly improved upon TEGDMA inclusion. Lastly, while the swelling of the cast composite in 37 °C water increased slightly, the mechanical properties (tensile strength, toughness, and stiffness) of the cast composite increased by at least an order of magnitude upon TEGDMA addition, and all composites demonstrated MSC cytocompatibility after 24 h. Overall, TEGDMA shows promise as an additive to tune properties of the GelMA-nHA system towards use in tissue engineering applications.

Critical review of water activities and microbiology of drying of meats

The drying of meat is one of the least expensive and most effective ways to preserve meat. This article reviews the influence of intrinsic and extrinsic parameters of foods in relation to the drying of meat and the role of microbial activities in the drying and storage of meat. The critical role of water activity and its relationship with other physical and chemical parameters and microbial survival in the drying of meat is also reviewed in detail. This article ends with a description of the various methods to measure water activity in foods. The conclusion is that the drying of meat is a highly complex phenomenon which is influenced by the composition of meat, its water holding capacity, the processing of meat, and various microorganisms found on meat before and after the drying process. There is no doubt that the drying of meat is an effective preservation process, but attention should be placed on the possible survival of microorganisms in the process in order to prevent spoilage and food-borne diseases.