We show that a finitely generated, residually finite group has the Haagerup property (Gromov's a‐T‐menability) if and only if one (or equivalently, all) of its box spaces admits a fibred coarse embedding into Hilbert space. In contrast, the box spaces of a finitely generated, residually finite hyperbolic group with property (T) do not admit a fibred coarse embedding into Hilbert space, but do admit a fibred coarse embedding into an ℓp‐space for some p>2.

Cationic β-lactoglobulin (CBLG) was developed as a bioavailability enhancer for poorly absorbed bioactives. At most 11 anionic amino acid residues of β-lactoglobulin (BLG) were substituted by ethylenediamine (EDA), resulting in a highly positive surface charge (zeta potential up to 39 mV at pH 7.0) and significantly increased surface hydrophobicity. These changes conferred CBLG with desirable water solubility and improved mucoadhesion by at most 252%, according to quartz crystal microbalance (QCM) study. Furthermore, CBLG inherited the unique resistance to gastric digestion from BLG, while the digestion under simulated intestinal condition was significantly improved. The latter was possibly due to the formation of aspartic acid-EDA conjugates, together with the randomization of protein conformation related with decreased percentage of β-sheet. Compared to BLG, CBLG formed smaller (75-94 nm), more uniform nanoparticles by the acetone-desolvation method. These merits made CBLG a useful material that provides desirable solubility, controlled release, and enhanced absorption to nutraceuticals or drugs.

No abstract

BLG (beta-lactoglobulin) and CBLG (cationic BLG developed by our lab) were evaluated as potential nutraceutical/drug carriers. The cationic corona conferred CBLG with superior integrity and drug retention under gastrointestinal conditions, at most 40-fold higher mucoadhesion, up to 30-fold greater transepithelial permeation and, at most 285% higher cellular uptake, compared to BLG. Furthermore, the more hydrophilic CBLG species exhibited better mucoadhesion, while the more hydrophobic one exhibited higher cellular uptake. Intriguingly, protein molecules were more cytotoxic and exhibited up to 175% higher tight junction-opening capacity than did protein nanoparticles, whereas the nanoparticles displayed up to 770% higher mucoadhesion, greater transepithelial permeation and elevated cellular uptake. Finally, all these surface properties and performances were significantly altered as CBLG bound to serum proteins. Possible mechanisms underlying these findings are discussed in detail. This research sheds some light on the development of protein-based nanoencapsulants and their performance upon oral administration.