New foods and natural biological modulators have recently become of scientific interest in the investigation of the value of traditional medical therapeutics. Glucans have an important part in this renewed interest. These fungal wall components are claimed to be useful for various medical purposes and they are obtained from medicinal mushrooms commonly used in traditional Oriental medicine. The immunotherapeutic properties of fungi extracts have been reported, including the enhancement of anticancer immunity responses. These properties are principally related to the stimulation of cells of the innate immune system. The discovery of specific receptors for glucans on dendritic cells (dectin-1), as well as interactions with other receptors, mainly expressed by innate immune cells (e.g., Toll-like receptors, complement receptor-3), have raised new attention toward these products as suitable therapeutic agents. We briefly review the characteristics of the glucans from mycelial walls as modulators of the immunity and their possible use as antitumor treatments.

For centuries human civilization has cultivated oats, and now they are consumed in various forms of food, from instant breakfasts to beverages. They are a nutrient-rich food containing linear mixed-linkage (1 → 3) (1 → 4)-β-d-glucans, which are relatively well soluble in water and responsible for various biological effects: the regulation of the blood cholesterol level, as well as being anti-inflammatory, prebiotic, antioxidant, and tumor-preventing. Numerous studies, especially in the last two decades, highlight the differences in the biological properties of the oat β-d-glucan fractions of low, medium, and high molecular weight. These fractions differ in their features due to variations in bioavailability related to the rheological properties of these polysaccharides, and their association with food matrices, purity, and mode of preparation or modification. There is strong evidence that, under different conditions, the molecular weight may determine the potency of oat-extracted β-d-glucans. In this review, we intend to give a concise overview of the properties and studies of the biological activities of oat β-d-glucan preparations depending on their molecular weight and how they represent a prospective ingredient of functional food with the potential to prevent or modulate various pathological conditions.

Nanoparticles are constructs that can be used for cellular interventions and targeted drug delivery. They are useful for overcoming the dose-related toxic effects of drugs or diagnostic preparations by predominant or selective accumulation in the pathologic tissues. Gadolinium(III) compounds are largely used as contrast agents in magnetic resonance imaging (MRI) but may have toxic effects, especially in nephropathic patients, due to the dose required for use in MRI. Here, we describe the preparation of new multifunctional NaGdF₄:Yb³⁺/Er³⁺ nanoparticles, their characteristic properties, and some preliminary data about their effect on cell viability and tissue localization. Hexagonal-phase NaGdF₄ nanocrystals that were doped with optically active Yb³⁺ and Er³⁺ ions, were synthesized by coprecipitation of lanthanide chlorides in octadec-1-ene at high temperature, stabilized by oleic acid, and subsequently coated with a thin silica layer. The morphology, elemental composition, crystalline structure, and SiO₂ coating of the prepared NaGdF₄:Yb³⁺/Er³⁺@SiO₂ nanoparticles were characterized in detail by transmission electron microscopy (TEM) combined with energy-dispersive spectroscopy (TEM/EDX) and selected area electron diffraction (TEM/SAED) and attenuated total reflection Fourier transform infrared (ATR FTIR) spectroscopy. The upconversion and paramagnetic properties of the particles were measured using confocal microscopy and MRI, respectively. The biocompatibility of the NaGdF₄:Yb³⁺/Er³⁺@SiO₂ nanoparticles was tested in vitro using mouse 3T3 fibroblasts and B16F10 melanoma cells. Particle localization was evaluated ex vivo in tumor, liver, and brain tissues of B16F10 melanoma bearing mice after intravenous administration. The NaGdF₄:Yb³⁺/Er³⁺@SiO₂ particles proved to be non-toxic at moderate concentrations. Particle localization within the organs was demonstrated by analysis of the tissues using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and showed vascular localization.

Nanoparticle (NP)-based materials are promising agents for enhancing cancer diagnosis and treatment. Once functionalized for selective targeting of tumor-expressed molecules, they can specifically deliver drugs and diagnostic molecules inside tumor cells. In the present work, we evaluated the in vivo melanoma-targeting ability of a nanovector (HFt-MSH-PEG) based on human protein ferritin (HFt), functionalized with both melanoma-targeting melanoma stimulating hormone (α-MSH) and stabilizing poly(ethylene glycol) (PEG) molecules. Independent and complementary techniques, such as whole-specimen confocal microscopy and magnetic resonance imaging, were used to detect in vivo localization of NP constructs with suitable tracers (i.e., fluorophores or magnetic metals). Targeted HFt-MSH-PEG NPs accumulated persistently at the level of primary melanoma and with high selectivity with respect to other organs. Melanoma localization of untargeted HFt-PEG NPs, which lack the -MSH moiety, was less pronounced. Furthermore, HFt-MSH-PEG NPs accumulated to a significantly lower extent and with a different distribution in a diverse type of tumor (TS/A adenocarcinoma), which does not express α-MSH receptors. Finally, in a spontaneous lung metastasis model, HFt-MSH-PEG NPs localized at the metastasis level as well. These results suggest that HFt-MSH-PEG NPs are suitable carriers for selective in vivo delivery of diagnostic or therapeutic agents to cutaneous melanoma.

Cancer, bacteria, and immunity relationships are much-debated topics in the last decade. Microbiome’s importance for metabolic and immunologic modulation of the organism adaptation and responses has become progressively evident, and models to study these relationships, especially about carcinogenesis, have acquired primary importance. The availability of germ-free (GF) animals, i.e., animals born and maintained under completely sterile conditions avoiding the microbiome development offers a unique tool to investigate the role that bacteria can have in carcinogenesis and tumor development. The comparison between GF animals with the conventional (CV) counterpart with microbiome can help to evidence conditions and mechanisms directly involving bacterial activities in the modulation of carcinogenesis processes. Here, we review the literature about spontaneous cancer and cancer modeling in GF animals since the early studies, trying to offer a practical overview on the argument.

Dictyosphaerium chlorelloides is a green microalga from the Chlorella clade that produces highly viscous exocellular polysaccharides. The cell wall polysaccharides of this alga have not been studied in detail. In this article, water-soluble polysaccharides from D. chlorelloides biomass were extracted with hot water and purified by preparative chromatography. The composition, structural features and molecular masses of subsequently eluted fractions F1, F2, F3, F4 and F5 (minor) were determined. Three high-yield products F1, F3 and F4 consisted mainly of galactopyranosyl, 2-O-methyl-galactopyranosyl, rhamnopyranosyl and mannopyranosyl units at different proportions, while F2 was rich in glucose. Immunoactivity of these fractions was evidenced in a mixed population of immune cells derived from mice spleens after incubation with polysaccharides by flow cytometry, MTT and Immunospot assays. These fractions, except F2, demonstrated selective immunostimulant activity, and the F1 fraction induced the most potent effect, closely followed by the F3 and F4 fractions. The in vivo mechanism of their action is associated with the activation of innate immunity and shapes the immune response to the Th1 type.