Self-assembled nanogels made of hydrophobized mannan or pullulan were obtained using a versatile, simple, reproducible and low-cost method. Structural features, size, shape, surface charge and stability of the nanogels were studied using hydrogen nuclear magnetic resonance, cryo-field emission scanning electron microscopy and dynamic light scattering. Nanogel based on vinyl methacrylated mannan was selected for further characterization among others because its synthesis is much easier, cheaper and less time consuming, its cmc and size are smaller, it is less polydisperse, and more stable at pH 3–8, in salt or urea solutions being consequently more suitable for biological applications. Proteins (bovine serum albumin or ovalbumin) and hydrophobic drugs (curcumin) are spontaneously incorporated in the mannan nanogel, being stabilized by the hydrophobic domains randomly distributed within the nanogel, opening the possibility for the development of applications as potential delivery systems for therapeutic molecules. No cytotoxicity is detected up to about 0.4 mg/mL of mannan nanogel in mouse embryo fibroblast cell line 3T3 and mouse bone marrow-derived macrophages (BMDM) using cell proliferation, lactate dehydrogenase and Live/Dead assays. Comet assay, under the tested conditions, reveals no DNA damage in fibroblasts, which seems to occur in the case of BMDM. The internalization kinetics, uptake mechanisms and intracellular trafficking pathways of mannan nanogel in mouse BMDM was assessed by flow cytometry and confocal laser scanning microscopy, using fluorescently conjugated nanogel. The mannan nanogel does not affect blood coagulation, does not induce complement activation and retards the fibril formation of both Alzheimer’s disease-associated amyloidβpeptide and haemodialysis-associated amyloidosisβ2 microglobulin, as was assessed by fluorometric thrombin generation assay, Western blot, and continuous thioflavin T fluorescence assay, respectively. Mannan nanogel has potential immunological adjuvant activity, as evaluated on the specific immune response to ovalbumin in intradermally immunized BALB/c mice. Elicited ovalbumin-specific antibodies were predominantly of IgG1 subclass indicating a T helper 2-type bias.
