Characterisation of spray dried microencapsules with amorphous lutein nanoparticles: Enhancement of processability, dissolution rate, and storage stability

A design of Tetrastigma hemsleyanum's flavonoid loaded polyvinylpyrrolidone nanoparticles for improving its bioavailability and biological activities

Flavonoids in plant extracts exhibit significant biological activities but are limited by their low bioavailability. This research aimed to improve the functional properties by synthesizing polyvinylpyrrolidone (PVP) nanoparticles using flavonoids derived from T. hemsleyanum. 208 flavonoids were identified using ultrahigh-performance-mass/mass spectrometry and used for nanoparticle preparation. The nanoparticles exhibited 24 % and 55 % higher equilibrium dissolution rates in simulated intestinal and gastric fluids than free flavonoids. With spherical morphologies, 100 nm size and - 26.7 mV zeta potential, these nanoparticles showed remarkable improvements in biological activities, including 1.5-fold enhancement in antioxidant capacity, HeLa cell inhibition, and antimicrobial efficacy, and a 5-fold increase in anti-inflammatory effects compared to unencapsulated flavonoids. This research has established a methodological system that could effectively enhance the utilization rate of flavonoids in plant extracts, offering promising potential for application in functional foods.

The study on preparation, stability and anti-allergic efficacy of phycocyanin microcapsules

The study aimed to investigate the stability and anti-allergic efficacy of phycocyanin through the construction of microcapsules. Phycocyanin (PC), a blue pigment found in microalgae, has attracted significant attention due to its anti-allergic properties. However, it is susceptible to instability when exposed to light, heat, and changes in pH. To address this issue, phycocyanin microcapsules were prepared using sodium alginate (SA), calcium chloride and chitosan (CS) as wall materials. The structures of microcapsules were carried out using scanning electron microscopy (SEM), fourier transform infrared spectroscopy, and particle size measurements that confirmed the successful encapsulation of PC within the microcapsules. The optimal effect was achieved when the mass ratio of PC to SA was 1:3, resulting in an embedding rate of 70.92 %. Stability studies shown that phycocyanin microcapsules exhibited the highest pigment retention rate under conditions of pH 6, darkness and a temperature of 37 °C. Furthermore, in vivo testing on mouse revealed a strong anti-allergic effect. These findings indicate that microcapsules prepared with phycocyanin as the core material exhibit high stability and a favorable anti-allergic effect, suggesting significant potential. This study serves as a reference for the further development of anti-allergic foods that can effectively prevent or alleviate food allergies.

Recent updates of carotenoid encapsulation by spray-drying technique

Carotenoids are compounds sensitive to environmental factors such as light, heat, and oxygen, which can result in the loss of their properties due to isomerisation and oxidation. To overcome this problem, spray drying encapsulation has been widely used as a method to protect and stabilise carotenoids in different wall materials. This article summarises the findings and research on spray drying encapsulation of carotenoids over the past 15 years, with an emphasis on the importance of controlling the operational conditions of the drying process and the association of different wall materials (proteins and polysaccharides), promising to increase encapsulation efficiency and stabilise carotenoids, with perspectives and trends in applications. The use of spray drying for carotenoid microencapsulation can open up new opportunities for controlled delivery of beneficial compounds. Based on the study, it is expected to provide information for researchers, professionals, and companies interested in the development of functional food products.

pH-driven fabrication of a caseinate-pectin polyelectrolyte complex as a promising carrier for lutein and zeaxanthin delivery: Microencapsulation, stability, and sustained release properties

In this study, caseinate-pectin polyelectrolyte complexes and co-solutions were successfully fabricated at pH 3.0 and 7.0, respectively, to encapsulate bioactive molecules. During the fabrication process, the effect of the sequence in which each component was added on lutein/zeaxanthin (Lut/Zx) complexation with sodium caseinate (NaCas) was investigated. The protective effect of the polyelectrolyte complex and co-solution for Lut/Zx in liquid formulations was compared with that of a binary system containing only caseinate and Lut/Zx. Compared with the binary system, the polyelectrolyte complex at pH 3.0 further enhanced the chemical stability of Lut/Zx during storage, whereas the co-solution at pH 7.0 did not exhibit this ability. Unexpectedly, NaCas-Lut/Zx - pectin (NC-L/Z-P) with a theoretically sandwich structure did not exhibit better protection than NaCas-pectin-Lut/Zx (NC-P-L/Z). Fluorescence quenching spectra revealed that the addition of NaCas to Lut/Zx and ultimately to pectin resulted in the formation of a sandwich structure, which was soon followed by structural rebalancing. Finally, freshly prepared NC-L/Z-P complexes were lyophilized to stabilize their sandwich structure, resulting in improved encapsulation and sustained-release properties compared with those of the dried NC-P-L/Z. These results suggest that protein-polysaccharide complexes, combined with timely dehydration, enhance the combination of Lut/Zx with caseinate, leading to heightened protective effects.

Microencapsulated granaticins from Streptomyces vilmorinianum YP1: Optimization, physiochemical characterization and storage stability

Granaticins are natural pigments derived from microorganisms with promising bioactivity. However, their practical applications have been restricted due to inherent instability. To improve the stability of granaticins from the novel strain Streptomyces vilmorinianum YP1, microcapsules were prepared using gum Arabic (GA) by a freeze-drying method. The optimal parameters for microencapsulation were determined using response surface methodology. Under the optimal conditions (GA 9.2% (v/v), a wall/-core ratio 4.8 (w/w), encapsulating temperature 29 °C), the maximum encapsulation efficiency achieved was 93.64%. The microcapsules were irregular single crystals with an average particle size of 206.37 ± 2.51 nm. Stability testing indicated improved stability of the microencapsulated granaticins. Notably, granaticnic B retention increased by 17.0% and 6.6% after exposure to sunlight and storage at 4 °C, respectively. These finding suggest that GA as a well material significantly enhances the stability of granaticins from S. vilmorinianum YP1, facilitating their potential applications.

Cocrystal of Lutein with Improved Stability and Bioavailability

Lutein (LT) is a natural carotenoid and is widely used for its vision protection and antioxidant activity. However, the long-chain polyene structure makes lutein sensitive to light and oxygen and poses many difficulties in the production, processing, and storage. In addition, the special chemical structure of LT leads to low solubility and bioavailability. In this study, we propose an efficient solution to address these issues. A cocrystal of LT with adipic acid (LT-APC) was obtained for the first time. The cocrystals were fully characterized. After cocrystallization, the melting point of marketed LT was increased. The chemical stability of LT was significantly improved, and the influence of impurities on stability was limited. Dissolution experiments were performed in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) and the cocrystal generated a much higher apparent solubility. To deepen insight into the mechanisms underlying the cocrystal's improved solubility, wettability tests were performed by contact angle determination and film flotation methods. The cocrystal presented better wettability than the marketed LT. Finally, pharmacokinetic studies of marketed LT and its cocrystal were conducted in rats. The results showed that the cocrystal exhibited 3.4 times higher C max and 2.2 times higher AUC at a single dose compared with marketed LT.

Improvements of Solubility and Bioavailability of Lutein Through Grafting with Hydrophilic Polyacrylic Acid

In this study, polyacrylic acid grafted lutein (PAA-g-lutein) was prepared by hydrophilic modification of lutein with polyacrylic acid (PAA) through Steglish esterification method. The unreacted lutein was loaded in micelles formed by self-assembly of graft copolymers in water to form composite nanoparticles. The bioaccessibility and bioavailability of lutein nanoparticles were studied by in vitro and in vivo digestion experiments. Compared with free lutein, the saturated solubility and bioaccessibility of lutein nanoparticles were increased by 78 times and 3.6 times, respectively. The pharmacokinetics results in the mice model showed that the maximum concentration (Cmax) and area under concentration-time curve (AUC) of plasma of mice were increased by 3.05 and 6.07 times with lutein nanoparticles compared with free lutein. Meanwhile, the prepared lutein nanoparticles also promoted the accumulation of lutein in the liver, mesenteric adipose, and eyeballs. These results indicate that graft copolymerization of lutein with water-soluble polymers to form nanoparticles is an effective method to promote the bioavailability of lutein in vivo. Moreover, this method is simple and applicable, and can also be used for the modification of other bioactive molecules.

Characterization of Spray-Dried Microcapsules of Paprika Oleoresin Induced by Ultrasound and High-Pressure Homogenization: Physicochemical Properties and Storage Stability

As an indispensable process in the microencapsulation of active substances, emulsion preparation has a significant impact on microencapsulated products. In this study, five primary emulsions of paprika oleoresin (PO, the natural colourant extracted from the fruit peel of Capsicum annuum L.) with different particle sizes (255-901.7 nm) were prepared using three industrialized pulverization-inducing techniques (stirring, ultrasound induction, and high-pressure homogenization). Subsequently, the PO emulsion was microencapsulated via spray drying. The effects of the different induction methods on the physicochemical properties, digestive behaviour, antioxidant activity, and storage stability of PO microencapsulated powder were investigated. The results showed that ultrasound and high-pressure homogenization induction could improve the encapsulation efficiency, solubility, and rehydration capacity of the microcapsules. In vitro digestion studies showed that ultrasound and high-pressure homogenization induction significantly increased the apparent solubility and dissolution of the microcapsules. High-pressure homogenization induction significantly improved the antioxidant capacity of the microcapsules, while high-intensity ultrasound (600 W) induction slowed down the degradation of the microcapsule fats and oils under short-term UV and long-term natural light exposure. Our study showed that ultrasound and high-pressure homogenization equipment could successfully be used to prepare emulsions containing nanoscale capsicum oil resin particles, improve their functional properties, and enhance the oral bioavailability of this bioactive product.

Excipient-free nanodispersions dominated by amphiphilic glycosides for bioavailability enhancement of hydrophobic aglycones, a case of glycyrrhetinic acid with diammonium glycyrrhizinate

Natural aglycones, a major ingredient accompanied by glycosides in plants, have played an important role in the treatment of various diseases. However, their bioavailability is limited by their poor water solubility. In contrast to previous efforts that required the use of new exotic materials which may raise concerns about biocompatibility, we report the first case of excipient-free nanodispersions in which an insoluble glycyrrhetinic acid (GA) assembled with its amphiphilic parent drug diammonium glycyrrhizinate (DG) into water-dispersible nanodispersions (130.8 nm for particle size and 91.74% for encapsulation efficiency). This strategy largely increased GA's water apparent solubility by hundreds of times to 549.0 μg/mL with a high cumulative dissolution percentage in vitro greater than 80% in 5 min. The study on the formation mechanism showed that the OH, C-O and C=O group stretching peaks shifted in the FTIR spectra of GA-DG nanodispersions, while the COOH peak (δ _COOH 12.19 ppm) disappeared in the ¹H NMR spectrum of GA-DG nanodispersions, indicating that carboxyl groups on GA may interact with the hydroxyl groups of DG in solution. Molecular dynamics simulations suggested that both hydrophobic interactions and hydrogen-bond interactions contribute to the coassembly of GA and DG molecules in aqueous solution. Oral pharmacokinetic studies in rats demonstrated that such nanodispersions have a significant increase in C_max and AUC_0-t of 2.45- and 3.45-fold compared with those for GA, respectively. Therefore, this strategy, employing amphiphilic glycosides as excipients to prepare nanodispersions, not using new materials, paves the way for the further application of hydrophobic aglycone drugs.