Research Progress of Aluminum Phosphate Adjuvants and Their Action Mechanisms.

Although hundreds of different adjuvants have been tried, aluminum-containing adjuvants are by far the most widely used currently. It is worth mentioning that although aluminum-containing adjuvants have been commonly applied in vaccine production, their acting mechanism remains not completely clear. Thus far, researchers have proposed the following mechanisms: (1) depot effect, (2) phagocytosis, (3) activation of pro-inflammatory signaling pathway NLRP3, (4) host cell DNA release, and other mechanisms of action. Having an overview on recent studies to increase our comprehension on the mechanisms by which aluminum-containing adjuvants adsorb antigens and the effects of adsorption on antigen stability and immune response has become a mainstream research trend. Aluminum-containing adjuvants can enhance immune response through a variety of molecular pathways, but there are still significant challenges in designing effective immune-stimulating vaccine delivery systems with aluminum-containing adjuvants. At present, studies on the acting mechanism of aluminum-containing adjuvants mainly focus on aluminum hydroxide adjuvants. This review will take aluminum phosphate as a representative to discuss the immune stimulation mechanism of aluminum phosphate adjuvants and the differences between aluminum phosphate adjuvants and aluminum hydroxide adjuvants, as well as the research progress on the improvement of aluminum phosphate adjuvants (including the improvement of the adjuvant formula, nano-aluminum phosphate adjuvants and a first-grade composite adjuvant containing aluminum phosphate). Based on such related knowledge, determining optimal formulation to develop effective and safe aluminium-containing adjuvants for different vaccines will become more substantiated.

A comparison study on the release kinetics and mechanism of bovine serum albumin and nanoencapsulated albumin from hydrogel networks.

An in situ-forming biodegradable hydrogel network has been developed to achieve extended release of protein drugs. Hyaluronic acids (HA) were selected as the scaffolding materials, and modified to afford thiolated HA (HASH) and methacrylated HA (HAME). Under near physiological conditions, a mixture of HASH and HAME achieved efficient sol-gel transition within 10 min at 37 °C. A systematic study was performed to characterize the morphology, rheological properties, swelling, degradation, and biocompatibility of the obtained hydrogel networks. Next, bovine serum albumin (BSA) and its nanocapsules were entrapped in the hydrogel network. Standard in vitro release studies and mathematic modeling were performed to gain insights into the release kinetics and mechanisms of protein drugs from the hydrogel network. For the hydrogel-nanocapsule hybrid system, a mathematical model combining the release processes from nanocapsules and hydrogel networks has been proposed to describe the release behavior of BSA from nanocapsules entrapped in the hydrogel network.

TransportDB: a comprehensive database resource for cytoplasmic membrane transport systems and outer membrane channels.

TransportDB (http://www.membranetransport.org/) is a comprehensive database resource of information on cytoplasmic membrane transporters and outer membrane channels in organisms whose complete genome sequences are available. The complete set of membrane transport systems and outer membrane channels of each organism are annotated based on a series of experimental and bioinformatic evidence and classified into different types and families according to their mode of transport, bioenergetics, molecular phylogeny and substrate specificities. User-friendly web interfaces are designed for easy access, query and download of the data. Features of the TransportDB website include text-based and BLAST search tools against known transporter and outer membrane channel proteins; comparison of transporter and outer membrane channel contents from different organisms; known 3D structures of transporters, and phylogenetic trees of transporter families. On individual protein pages, users can find detailed functional annotation, supporting bioinformatic evidence, protein/DNA sequences, publications and cross-referenced external online resource links. TransportDB has now been in existence for over 10 years and continues to be regularly updated with new evidence and data from newly sequenced genomes, as well as having new features added periodically.