Water-Based Synthesis of β-Sheet-Like Supramolecular Metallohydrogel Organized by Using a Native Ultrashort Peptide Sequence.

Designing supramolecular hydrogels using short peptides is challenging. To control self-assembly, a certain amount of organic solvent is typically added to the system, or the short peptide is modified with a functional group that is hydrophobic, hydrophilic, or highly coordinative. We discovered that l-His-l-Ile-l-Thr (HIT), a very short unmodified "native" tripeptide, selectively responds to Cu ions in pure water to form a transparent supramolecular metallohydrogel.

Enhanced water dispersibility and Caco-2 cell monolayer permeability of quercetin by complexation with casein hydrolysate.

Although quercetin (Que) has many beneficial therapeutic effects on the human body, its oral bioavailability is poor because of its low water solubility. Herein, we describe the preparation of casein hydrolysate (Pep ) and its use as a dispersant to enhance the water dispersibility of Que resulting in an improvement of its bioavailability. By complexation with Pep , the apparent solubility of Que in the complex (Que@Pep ) was significantly increased under acidic and neutral conditions.

Dominant factors that determine the dissolution state of complexes between poorly water-soluble ingredients and casein hydrolysate.

Casein hydrolysate (Pep) is a dispersant for poorly water-soluble drugs and nutraceutical ingredients. However, two types of complexes may be between Pep and poorly water-soluble molecules: those that are (1) dispersed as hydrocolloids in aqueous media with a particle size of 100-500 nm; and (2) not hydrocolloids, as indicated by permeability of the complex through an ultrafiltration (UF) membrane and the fact that the particle size is ambiguous by dynamic light scattering. This study was conducted to clarify the factors that determine the dissolution state of the complexes between poorly water-soluble ingredients and casein hydrolysate.

Enhanced water dispersibility and permeability through a Caco-2 cell monolayer of β-cryptoxanthin extracted from kumquats by complexation with casein.

β-Cryptoxanthin (BCX) possesses potential therapeutic and health benefits. However, BCX absorption is low because of its poor aqueous solubility. In this study, a complex between BCX and casein (Cas) was prepared to improve the water dispersibility and bioavailability of BCX.

Development of highly water-dispersible complexes between coenzyme Q and protein hydrolysates.

The water-solubility of coenzyme Q (CoQ) is extremely low because of its hydrophobicity, which results in low bioavailability. In this study, peptide mixtures derived from different proteins (casein, albumin, gelatin, lysozyme, zein and hemoglobin) were prepared and used as dispersants ofCoQ. Most peptide mixtures, except for that derived from lysozyme, enhanced the water-dispersibility of CoQ by forming complexes with CoQ.

Poly(amine-co-ester) nanoparticles for effective Nogo-B knockdown in the liver.

Degradable poly(amine-co-ester) (PACE) terpolymers hold tremendous promise for siRNA delivery because these materials can be formulated into delivery vehicles with highly efficient siRNA encapsulation, providing effective knockdown with low toxicity. Here, we demonstrate that PACE nanoparticles (NPs) provide substantial protein knockdown in human embryonic kidney cells (HEK293) and hard-to-transfect primary human umbilical vein endothelial cells (HUVECs). After intravenous administration, NPs of solid PACE (sPACE)-synthesized with high monomer content of a hydrophobic lactone-accumulated in the liver and, to a lesser extent, in other tissues.

Improvements in the water dispersibility of paclitaxel by complexing with synthetic peptides derived from β-casein.

Recently, digestive peptides prepared as a casein hydrolysate have been found to be an effective dispersant for the poorly water-soluble drug paclitaxel (Ptx). A major hydrophobic peptide in the digested peptides was identified as YQEPVLGPVRGPFPIIV (PepY) by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry with the "LIFT" technique. In the present study, three peptides PepY, VVVPPFLQPEVMGVSKV (PepV), and KFQSEEQQQTEDELQDK (PepK) were chemically synthesized by Fmoc solid-phase synthesis to compare their function as dispersants for Ptx.

Enhancing the water dispersibility of paclitaxel by complexation with hydrophobic peptides.

The complex between paclitaxel (Ptx) and a peptide mixture (Pep) was prepared to enhance of the water-dispersibility of Ptx. Pep was prepared by enzymatic hydrolysis of casein, followed by fractionation using ammonium sulfate precipitation and ultrafiltration. The Ptx and Pep complex (Ptx-Pep) was prepared by mixing an ethanol solution of Ptx and an aqueous solution of Pep followed by lyophilization.

Enhancement of water solubility of indomethacin by complexation with protein hydrolysate.

Complex formation between indomethacin (Indo) and casein hydrolysate was developed as a novel technique for enhancing the water solubility of Indo. The complex (Indo-Pep) was prepared by mixing an ethanol solution of Indo and an aqueous solution of peptide mixture, followed by lyophilization. The water solubility of Indo-Pep under weakly acidic and neutral conditions is much higher than that of Indo alone.