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Nanotechnology is an emerging field of science, and nanotechnological concepts have been intensively studied for potential applications in the food industry. Nanoparticles (with dimensions ranging from one to several hundred nanometers) have specific characteristics and better functionality, thanks to their size and other physicochemical properties. Polyphenols are recognized as active compounds that have several putative beneficial properties, including antioxidant, antimicrobial, and anticancer activity. However, the use of polyphenols as functional food ingredients faces numerous challenges, such as their poor stability, solubility, and bioavailability. These difficulties could be solved relatively easily by the application of encapsulation. The objective of this review is to present the most recent accomplishments in the usage of polyphenol-loaded nanoparticles in food science. Nanoparticles loaded with polyphenols and their applications as active ingredients for improving physicochemical and functional properties of food, or as components of active packaging materials, were critically reviewed. Potential adverse effects of polyphenol-loaded nanomaterials are also discussed.

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In this study a bottom-up approach of designing functional ingredients from green tea extract is proposed by a systematic investigation of 12 different natural biopolymers and their efficiency as carrier materials of green tea bioactive compounds by spray drying at low temperature (130°C). Screening of carriers revealed that inulin and whey proteins provide the highest product yields (67.04 and 65.18 %, respectively) and, accompanied with pectin, also the highest total polyphenols (67.5-82.2 %) and flavan-3-ols (93.7-75.9 %) loading capacity. Up to 162 mg/g of (−)−epigallocatechin gallate (EGCG) was achieved, while low-caffeine contents (<5 mg/g) indicated the potential of obtaining lowcaffeine functional ingredients. Employing alginate, carageenan and gums (acacia gum and xanthan) enabled the best colour preservation and highest chlorophyll content. Reconstituted green tea microencapsulates comprising modified starch, inulin or carageenan exhibited the lowest bitterness and astringency and the highest green tea flavour intensity as the most favourable sensory properties. An artificial neural network (ANN) designed based on the experimentally obtained results revealed hydrocolloid gums as the best encapsulants for achieving good physical properties, high EGCG contents and prolonged dissolution/release profiles while pectin, inulin and modified starch as the optimal ones in terms of the product yields, loading capacities and sensory properties. This indicates that a formulation comprising a combination of all of those biopolymers would provide potentially functional ingredients with encapsulated green tea phytochemicals, retained colour and improved sensory properties.

Remodelling of collagen fibers has been described during every phase of cancer genesis and progression. Changes in morphology and organization of collagen fibers contribute to the formation of microenvironment that favors cancer progression and development of metastasis. However, there are only few data about remodelling of collagen fibers in healthy looking mucosa distant from the cancer. Using SHG imaging, electron microscopy and specialized softwares (CT-FIRE, CurveAlign and FiberFit), we objectively visualized and quantified changes in morphology and organization of collagen fibers and investigated possible causes of collagen remodelling (change in syntheses, degradation and collagen cross-linking) in the colon mucosa 10 cm and 20 cm away from the cancer in comparison with healthy mucosa. We showed that in the lamina propria this far from the colon cancer, there were changes in collagen architecture (width, straightness, alignment of collagen fibers and collagen molecules inside fibers), increased representation of myofibroblasts and increase expression of collagen-remodelling enzymes (LOX and MMP2). Thus, the changes in organization of collagen fibers, which were already described in the cancer microenvironment, also exist in the mucosa far from the cancer, but smaller in magnitude. Extracellular matrix (ECM) is no longer considered as an inert substrate, a three-dimensional network which only "fills the spaces" between cells and provide mechanical support 1,2. Today, ECM is known to be a complex and dynamic structure, whose chemical and biophysical properties affect cell adhesion 3 , proliferation 4 morphology 5 , migration 6 , regulate tissue morphogenesis 7,8 and fluid volume in tissues 9. The most abundant component of ECM in the lamina propria of the colon mucosa is type I collagen. Remodelling of collagen fibers has been described in almost every solid cancer, including colorectal cancer. During tumor formation and progression, collagen remodelling is constantly carried out: degradation, synthesis, cross-linking of fibers, change of fiber orientation, and interaction of cells of the innate and acquired immune system with collagen fibers 10,11. Changes in morphology, representation, and organization of collagen fibers contribute to the formation of the microenvironment that favors tumor progression, primarily through its effect on cell migration and polarization 12. Also, remodelling of collagen fibers on premetastatic sites is of great importance in determination of survival and growth of disseminated cancer cells, and thus, formation of metastasis 13,14. Remodelling of collagen fibers may be a result of changes in synthesis, degradation or cross-linking. Main cells responsible for synthesis of collagen in colon mucosa are fibroblasts and myofibroblasts. The most important enzymes for degradation of collagen fibers are matrix metalloproteinases (MMPs). It has been shown that expression of MMP2 and MMP9 is increased in colorectal cancer and influences its progression and