The incoherent quasi-elastic neutron scattering study of poly(vinyl alcohol) based hydrogels was carried out to elucidate the dynamic state of water caged in polymeric matrixes with different degree of cross-linking and nature of the cross-linking agent. This investigation focuses on the determination of the relationship occurring between the diffusional parameters of water and the polymer network architecture. Analyzing the broadening factor of the dynamic structure factor, a marked supercooling of water was detected in all the matrixes under consideration. In all cases, the activation energies were about 4 kcal/mol indicating a hydrogen bond regime governing the matrix-solvent interaction. In some favorable cases, an insight on the polymer dynamics was also possible. The q-dependence of the broadening factor of polymer relaxation component revealed a behavior compatible with a bound random jump dynamics and concerning segmental motions of the chain coupled with the interaction with water.

complex drug delivery systems that are challenging to scale up and therefore have limited clinical and commercial translation. Although numerous nanoparticles have been widely developed and used for various applications, including biomedical applications, [2] there is a growing interest in nontoxic and degradable alternatives to first-generation synthetic nanomaterials. Ideally the synthesis of such nanoparticles needs to be cost effective, simple, green, reproducible, scalable, and the constitutive building blocks of the nanoparticles should be nontoxic, functional, biodegradable, and available on a large scale. Naturally occurring nanoparticles could be such a valid alternative. These nanoparticles include intracellular structures, such as magnetosomes [3] and glycogen, and extracellular assemblies such as lipoproteins and viruses. [3] Among these, glycogen is the most abundant and versatile biological nanoparticle, which fulfils the requirements for the fabrication of nanostructured biomaterials. Glycogen is nature's prime nanoparticle that exists in most organisms, from bacteria and archaea to humans, [4,5] as a vital component of the cellular energy machinery. It is a highly branched polysaccharide comprising repeating units of glucose connected by linear α-d-(1,4) glycosidic linkages with α-d-(1,6) branching, structured into roughly spherical nanoparticles that have a high water solubility and molecular weight.The use of polysaccharides as components for advanced materials has been an attractive concept for decades. [6,7] A key motive is that polysaccharides, as a natural biomaterial, are endowed with a level of biodegradability and biocompatibility. In addition, they can be easily modified chemically or biochemically to produce functional derivatives, which are important for various therapeutic applications. [8] The structures of polysaccharides vary considerably but span from linear to highly branched polymers with molecular weights ranging from thousands to millions, composed of mono-or disaccharides, or short-chain oligomers bound together by glycosidic linkages. [9] There is a rich history of research on the use of polysaccharides in a range of therapeutic applications including: i) soft tissue engineering, [10,11] where the materials can be designed to mimic the mechanical properties of the extracellular matrix in the tissue; ii) as drug, protein, or gene delivery systems, [7,12,13] where polysaccharides have a large number of reactive groups [14] that allow for tunable properties [12] such as pH-responsiveness; [15] and iii) as nanoprobes for cellular Biological nanoparticles found in living systems possess distinct molecular architectures and diverse functions. Glycogen is a unique biological polysaccharide nanoparticle fabricated by nature through a bottom-up approach. The biocatalytic synthesis of glycogen has evolved over time to form a nanometer-sized dendrimer-like structure (20-150 nm) with a highly branched surface and a dense core. This makes glycogen markedly different from other natur...

Recently, several studies have indicated an increased interest in the scientific community regarding the application of Cannabis sativa plants, and their extracts, for medicinal purposes. This plant of enormous medicinal potential has been legalised in an increasing number of countries globally. Due to the recent changes in therapeutic and recreational legislation, cannabis and cannabinoids are now frequently permitted for use in clinical settings. However, with their highly lipophilic features and very low aqueous solubility, cannabinoids are prone to degradation, specifically in solution, as they are light-, temperature-, and auto-oxidation-sensitive. Thus, plant-derived cannabinoids have been developed for oral, nasal-inhalation, intranasal, mucosal (sublingual and buccal), transcutaneous (transdermal), local (topical), and parenteral deliveries. Among these administrations routes, topical and transdermal products usually have a higher bioavailability rate with a prolonged steady-state plasma concentration. Additionally, these administrations have the potential to eliminate the psychotropic impacts of the drug by its diffusion into a nonreactive, dead stratum corneum. This modality avoids oral administration and, thus, the first-pass metabolism, leading to constant cannabinoid plasma levels. This review article investigates the practicality of delivering therapeutic cannabinoids via skin in accordance with existing literature.

There is a need for effective vaccine delivery systems and vaccine adjuvants without extraneous excipients that can compromise or minimize their efficacy. Vaccine adjuvants cytosine–phosphate–guanosine oligodeoxynucleotides (CpG ODNs) can effectively activate immune responses to secrete cytokines. However, CpG ODNs are not stable in serum due to enzymatic cleavage and are difficult to transport through cell membranes. Herein, DNA microcapsules made of CpG ODNs arranged into 3D nanostructures are developed to improve the serum stability and immunostimulatory effect of CpG. The DNA microcapsules allow encapsulation and co‐delivery of cargoes, including glycogen. The DNA capsules, with >4 million copies of CpG motifs per capsule, are internalized in cells and accumulate in endosomes, where the Toll‐like receptor 9 is engaged by CpG. The capsules induce up to 10‐fold and 20‐fold increases in tumor necrosis factor (TNF)‐α and interleukin (IL)‐6 secretion, respectively, in RAW264.7 cells compared with CpG ODNs. Furthermore, the microcapsules stimulate TNF‐α and IL‐6 secretion in a concentration‐ and time‐dependent manner. The immunostimulatory activity of the capsules correlates to their intracellular trafficking, endosomal confinement, and degradation, assessed by confocal and super‐resolution microscopy. These DNA capsules can serve as both adjuvants to stimulate an immune reaction and vehicles to encapsulate vaccine peptides/genes to achieve synergistic immune effects.