Synthesis, Characterization, and Retinol Stabilization of Fatty Amide-β-cyclodextrin Conjugates

Conversion of Retinyl Palmitate to Retinol by Wheat Bran Endogenous Lipase Reduces Vitamin A Stability

Wheat bran can be used as a cost-effective food ingredient to stabilise vitamin A. However, wheat bran endogenous enzymes have been shown to reduce vitamin A stability. In this study, we elucidated the mechanism for this negative effect in an accelerated storage experiment with model systems consisting of native or toasted wheat bran, soy oil and retinyl palmitate (RP). Both native and toasted wheat bran substantially stabilised RP. While RP was entirely degraded after ten days of storage in the absence of wheat bran, the RP retention after ten days was 22 ± 2% and 75 ± 5% in the presence of native and toasted bran, respectively. The significantly stronger stabilising effect of toasted bran was attributed to the absence of bran endogenous enzymes. In contrast to toasted bran systems, noticeable free fatty acid production was observed for native bran systems. However, this did not result in a pronounced lipid oxidation. Next to lipid hydrolysis, wheat bran lipase was shown to hydrolyse retinyl esters to the less stable retinol and fatty acids. This reaction could explain the major part, about 66 ± 5%, of the difference in RP stabilisation between native and toasted wheat bran.

Improvement of mild photoaged facial skin in middle-aged Chinese females by a supramolecular retinol plus acetyl hexapeptide-1 containing essence

Background

The anti-ageing gold standard, retinol, has been widely recognized for its anti-wrinkle benefits in the Chinese population. Studies have shown that Asians are more sensitive to retinol compared to their Caucasian counterparts, and it is generally recommended to use retinol once a day in the evening. However, there are few reports on the most appropriate concentration and frequency of retinol use in the general Chinese population.

Objectives

In this study, supramolecular retinol was prepared using cyclodextrin encapsulation technology, and the most appropriate concentration for the general Chinese population was investigated. Then, a cosmetic essence was developed by combining the classic supramolecular retinol, which promotes collagen regeneration, with acetyl hexapeptide-1, a popular ingredient known for reducing expression lines. The safety and efficacy of this cosmetic essence were studied through clinical tests.

Methods

First, a patch test was conducted on 32 healthy Chinese subjects to compare the tolerance of supramolecular retinol to non-encapsulated retinol and to select the optimal concentration of retinol. Then, an 8-week clinical study was conducted using a twice-daily cosmetic essence containing 0.1% supramolecular retinol and 0.02% acetyl hexapeptide-1 to treat mild photoaging in 32 middle-aged Chinese women. Dermatological evaluations and instrument measurements were taken at baseline, 4 weeks, and 8 weeks. Efficacy was assessed using facial skin wrinkles, textures, elasticity, firmness, pores, gloss and stratum corneum hydration. Tolerability was assessed throughout the study.

Results

Our patch test results showed that supramolecular retinol was better tolerated than non-encapsulated retinol, and our findings suggest that 0.1% was the approximate optimal retinol concentration for the general Chinese population. The cosmetic essence studied was effective in improving the appearance of photoaged skin in the Chinese population in all aspects studied and was well tolerated.

Conclusions

0.1% retinol is suitable for twice daily use in the general Chinese population. Data and records on efficacy dimensions of skin textures, elasticity, firmness, pores, gloss and stratum corneum hydration for retinol in the Chinese population are supplemented with our study. Cosmeceutical approaches targeting both static and dynamic wrinkles are of value for treating the photoaged Chinese population.

Oral Targeted Delivery of Imatinib by pH Responsive Copolymer Modulates Liver Fibrosis in the Mice Model

Liver fibrosis is a significant cause of morbidity and mortality without approved treatment. The therapeutic effects of Imatinib as a tyrosine kinase inhibitor on reversing liver fibrosis have already been shown. However, considering the conventional route of Imatinib administration, the amount of drug to be used is very high, and its side effects are raised. Therefore, we designed an efficient pH-sensitive polymer for the targeted delivery of Imatinib in treating a carbon tetrachloride (CCl4)-induced liver fibrosis. This nanotherapeutic system-based Vitamin A (VA)-modified Imatinib-loaded poly (lactic-co-glycolic acid)/Eudragit S100 (PLGA-ES100) has been successfully fabricated by adapting the solvent evaporation technique. The applying ES100 on the surface of our desired nanoparticles (NPs) protects drug release at the acidic pH of the gastric and guarantees the effective release of Imatinib at a higher pH of the intestine. Besides, VA-functionalized NPs could be an ideal efficient drug delivery system due to the high capacity of hepatic cell lines to absorb VA. For induction of liver fibrosis, CCL4 was intraperitoneally (IP) injected twice a week for six weeks in BALB/c mice. Oral administration of VA-targeted PLGA-ES100 NPs loaded with Rhodamine Red™ by live animal imaging showed a preferential accumulation of the selected NPs in the liver of mice. Besides, administrating targeted Imatinib-loaded NPs significantly decreased serum levels of ALT, and AST, and also reduced the expression of extracellular matrix components, including collagen I, collagen III, and α-SMA, considerably. Interestingly, histopathological evaluation of liver tissues through H&E and Masson's trichrome staining showed that oral administration of targeted Imatinib-loaded NPs reduced hepatic damage by enhancing hepatic structure condition. Also, the Sirius-red staining indicated a reduction in collagen expression during treatment with targeted NP containing Imatinib. The immunohistochemistry result on liver tissue shows a significant decrease in the expression of α-SMA in groups treated with targeted NP. In the meantime, administration of a very scarce dose of Imatinib via targeted NP caused a substantial decline in the expression of fibrosis marker genes (Collagen I, Collagen III, α-SMA). Our results confirmed that novel pH-sensitive VA-targeted PLGA-ES100 NPs could efficiently deliver Imatinib to the liver cells. Loading Imatinib in the PLGA-ES100/VA might overcome many challenges facing conventional Imatinib therapy, including gastrointestinal pH, the low concentration at the target region, and toxicity.

Encapsulation of sesamol and retinol using alginate and chitosan-coated W/O/W multiple emulsions containing Tween 80 and Span 80

The conditions of production of multiple W/O/W nanoemulsions containing sesamol and retinol were optimized using response surface methodology (RSM). Span 80 (5, 10, and 15 % w/v), Tween 80 (1, 5.5, and 10 % w/v), and water in oil ratio (W/O) (20, 30, and 40 %) were considered as independent variables while encapsulation efficiency (EE%) and particle size were taken as dependent variables. Alginate (Alg) and chitosan (CS) were also applied to form a deposit layer. An optimum sample with an EE of 92.93 % and particle size of 381.94 nm was produced when Tween 80, Span 80, and W/O were 6.24 %, 10.84 %, and 37.70 %, respectively. Based on the Fourier transform infrared spectroscopy (FTIR), detection of hydrophobic band (2899 cm^-1) approved the physical entrapment of biomolecules. Differential scanning calorimetry (DSC) indicated an endothermic peak at 236.48 °C associated with the ionic interactions of Alg-CS. Confocal laser scanning microscopy (CLSM) indicated Alg-CS complex deposit layer formed by electrostatic attraction surrounding the W/O/W multiple layers. The in vitro release of sesamol and retinol was 39 % of sesamol and 22 % of retinol in simulated gastric fluid (SGF) and 56 % and 22 % in simulated intestinal fluid (SIF), respectively.

An overview from simple host-guest systems to progressively complex supramolecular assemblies

Supramolecular chemistry involving macrocyclic hosts is a highly interdisciplinary and fast-growing research field in chemistry, biochemistry, and materials science. Host-guest based supramolecular assemblies, as constructed through non-covalent interactions, are highly dynamic in nature, and can be tuned easily using their responses to various external stimuli, providing a convenient approach to achieve excellent functional materials. Macrocyclic hosts, particularly cyclodextrins, cucurbit[n]urils, and calix[n]arenes, which have unique features like possessing hydrophobic cavities of different sizes, along with hydrophilic external surfaces, which are also amenable towards easy derivatizations, are versatile cavitands or host molecules to encapsulate diverse guest molecules to form stable host-guest complexes with many unique structures and properties. Interestingly, host-guest complexes possessing amphiphilic properties can easily lead to the formation of various advanced supramolecular assemblies, like pseudorotaxanes, rotaxanes, polyrotaxanes, supramolecular polymers, micelles, vesicles, supramolecular nanostructures, and so on. Moreover, these supramolecular assemblies, with varied morphologies and responsiveness towards external stimuli, have immense potential for applications in nanotechnology, materials science, biosensors, drug delivery, analytical chemistry and biomedical sciences. In this perspective, we present a stimulating overview, discussing simple host-guest systems to complex supramolecular assemblies in a systematic manner, aiming to encourage future researchers in this fascinating area of supramolecular chemistry to develop advanced supramolecular materials with superior functionalities, for their deployment in diverse applied areas.

Triple-target stimuli-responsive anti-COVID-19 face mask with physiological virus-inactivating agents

Conventional face masks to prevent SARS-CoV-2 transmission are mostly based on a passive filtration principle. Ideally, anti-COVID-19 masks should protect the carrier not only by size exclusion of virus aerosol particles, but also be able to capture and destroy or inactivate the virus. Here we present the proof-of-concept of a filter mat for such a mask, which actively attracts aerosol droplets and kills the virus. The electrospun mats are made of polycaprolactone (PCL) a hydrophilic, functionalizable and biodegradable polyester, into which inorganic polyphosphate (polyP) a physiological biocompatible, biodegradable and antivirally active polymer (chain length, ∼40 Pi units) has been integrated. A soluble Na-polyP as well as amorphous calcium polyP nanoparticles (Ca-polyP-NP) have been used. In this composition, the polyP component of the polyP-PCL mats is stable in aqueous protein-free environment, but capable of transforming into a gel-like coacervate upon contact with divalent cations and protein like mucin present in (virus containing) aerosol droplets. In addition, the Ca-polyP-NP are used as a carrier of tretinoin (all-trans retinoic acid) which blocks the function of the SARS-CoV-2 envelope (E) protein, an ion channel forming viroporin. The properties of this novel mask filter mats are as follows: First, to attract and to trap virus-like particles during the polyP coacervate formation induced in situ by aerosol droplets on the spun PCL fibers, as shown here by using SARS-CoV-2 mimicking fluorescent nanoparticles. Second, after disintegration the NP by the aerosol-mucus constituents, to release polyP that binds to and abolishes the function of the receptor binding domain of the viral spike protein. Third, to destroy the virus by releasing tretinoin, as shown by the disruption of virus-mimicking liposomes with the integrated recombinant viral viroporin. It is proposed that these properties, which are inducible (stimuli responsive), will allow the design of antiviral masks that are smart.

ANALYSIS OF CARBOHYDRATES AND GLYCOCONJUGATES BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY: AN UPDATE FOR 2015-2016

This review is the ninth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2016. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented over 30 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show no sign of deminishing. © 2020 Wiley Periodicals, Inc.

Complex systems that incorporate cyclodextrins to get materials for some specific applications

Cyclodextrins (CDs) are a family of biodegradable cyclic hydrocarbons composed of α-(1,4) linked glucopyranose subunits, the more common containing 6, 7 or 8 glucose units are named α, β and γ-cyclodextrins respectively. Since the discovery of CDs, they have attracted interest among scientists and the first studies were about the properties of the native compounds and in particular their use as catalysts of organic reactions. Characteristics features of different types of cyclodextrins stimulated investigation in different areas of research, due to its non-toxic and non-inmunogenic properties and also to the development of an improved industrial production. In this way, many materials with important properties have been developed. This mini-review will focus on chemical systems that use cyclodextrins, whatever linked covalently or mediated by the non covalent interactions, to build complex systems developed mainly during the last five years.