RESUMEN
Hypercrosslinked porous organic polymers (HCPs), a novel type of porous materials synthesized via the Friedel-Crafts reaction, are widely used in gas storage, heterogeneous catalysis, chromatographic separation, and organic pollutant capture. HCPs have the advantages of a wide monomer source, low cost, mild synthesis conditions, and easy functionalization. In recent years, HCPs have shown great application potential in solid phase extraction. Given their high specific surface area, excellent adsorption properties, diverse chemical structures, and easy chemical modification, HCPs have been successfully applied to the extraction of different types of analytes with efficient extraction performance. Based on the chemical structure of HCPs, their target analytes, and the adsorption mechanism, HCPs can be classified as hydrophobic, hydrophilic, and ionic species. Hydrophobic HCPs are usually constructed as extended conjugated structures by overcrosslinking aromatic compounds as monomers. Common monomers include ferrocene, triphenylamine, triphenylphosphine, etc. This type of HCPs shows good adsorption effects on nonpolar analytes such as benzuron herbicides and phthalates through strong π-π and hydrophobic interactions. Hydrophilic HCPs are prepared by introducing polar monomers or crosslinking agents, or by modifying polar functional groups. This type of adsorbent is commonly used to extract polar analytes such as nitroimidazole, chlorophenol, tetracycline, etc. In addition to hydrophobic forces, polar interactions, such as hydrogen-bonding and dipole-dipole interactions, also occur between the adsorbent and analyte. Ionic HCPs are mixed-mode solid phase extraction materials formed by introducing ionic functional groups into the polymer. Mixed-mode adsorbents usually have a dual reversed-phase/ion-exchange retention mechanism, which helps control the retention behavior of the adsorbent by adjusting the elution strength of the eluting solvent. In addition, the extraction mode can be switched by controlling the pH of the sample solution and eluting solvent. In this manner, matrix interferences can be removed while the target analytes are enriched. Ionic HCPs present a unique advantage in the extraction of acid-base drugs in water. The combination of new HCP extraction materials with modern analytical techniques, such as chromatography and mass spectrometry, has been widely used in environmental monitoring, food safety, and biochemical analyses. In this review, the characteristics and synthesis methods of HCPs are briefly introduced, and the application progress of different types of HCPs in cartridge-based solid phase extraction is described. Finally, the future outlook of HCP applications is discussed.
RESUMEN
Pulmonary anthrax is the most fatal clinical form of anthrax and currently available injectable vaccines do not provide adequate protection against it. Hence, next-generation vaccines that effectively induce immunity against pulmonary anthrax are urgently needed. In the present study, we prepared an attenuated and low protease activity Bacillus anthracis strain A16R-5.1 by deleting five of its extracellular protease activity-associated genes and its lef gene through the CRISPR-Cas9 genome editing system. This mutant strain was then used to formulate a lethal toxin (LeTx)-free culture supernatant extract (CSE) anthrax vaccine, of which half was protective antigen (PA). We generated liquid, powder, and powder reconstituted formulations that could be delivered by aerosolized intratracheal inoculation. All of them induced strong humoral, cellular, and mucosal immune responses. The vaccines also produced LeTx neutralizing antibodies and conferred full protection against the lethal aerosol challenges of B. anthracis Pasteur II spores in mice. Compared to the recombinant PA vaccine, the CSE anthrax vaccine with equal PA content provided superior immunoprotection against pulmonary anthrax. The preceding results suggest that the CSE anthrax vaccine developed herein is suitable and scalable for use in inhalational immunization against pulmonary anthrax.
