Host-guest complexes of estragole with β-cyclodextrin: an experimental and theoretical investigation

Microencapsulation of multi-component traditional Chinese herbs extracts and its application to traditional Chinese medicines loaded textiles

Extracts of traditional Chinese herbs (TCH) contain a variety of anti-allergic, anti-inflammatory and other bioactive factors. However, the defect of easy degradation or loss of active ingredients limits its application in traditional Chinese medicines (TCM) loaded textiles. In this work, TCH extracts containing different active ingredients were innovatively proposed as the core material of microcapsules. The feasibility of microencapsulation of multi-component TCH extracts in the essential oil state was initially demonstrated. Polyacrylate was also used as a binder to load the microcapsules onto the fabric to improve the durability and wash resistance of the treated fabric. Modeling the oil release of microcapsules for controlled release under different conditions may provide new possible uses for the materials. Results show that the constructed microcapsule has a smooth surface without depression and can be continuously released for over 30 days. The release behavior of microcapsules follows different release mechanisms and can be modulated by temperature and water molecules. The incorporation of microcapsules and polyacrylate does not significantly change the fabric's air permeability, water vapor transmission and hydrophilicity. The washing durability and friction properties of the microcapsule-based fabric are greatly improved, and it can withstand 30 washing tests and 200 friction tests. Moreover, the results of methyl thiazolyl tetrazolium (MTT) release assay using human dermal papilla cells (HDP) as an in vitro template confirm that the microcapsule has no toxic effects on human cells. Therefore, the successful microencapsulation of multi-component TCH extracts indicates their potential application in the field of TCM-loaded textiles.

Application of Starch, Cellulose, and Their Derivatives in the Development of Microparticle Drug-Delivery Systems

Micro- and nanotechnologies have been intensively studied in recent years as novel platforms for targeting and controlling the delivery of various pharmaceutical substances. Microparticulate drug delivery systems for oral, parenteral, or topical administration are multiple unit formulations, considered as powerful therapeutic tools for the treatment of various diseases, providing sustained drug release, enhanced drug stability, and precise dosing and directing the active substance to specific sites in the organism. The properties of these pharmaceutical formulations are highly dependent on the characteristics of the polymers used as drug carriers for their preparation. Starch and cellulose are among the most preferred biomaterials for biomedical applications due to their biocompatibility, biodegradability, and lack of toxicity. These polysaccharides and their derivatives, like dextrins (maltodextrin, cyclodextrins), ethylcellulose, methylcellulose, hydroxypropyl methylcellulose, carboxy methylcellulose, etc., have been widely used in pharmaceutical technology as excipients for the preparation of solid, semi-solid, and liquid dosage forms. Due to their accessibility and relatively easy particle-forming properties, starch and cellulose are promising materials for designing drug-loaded microparticles for various therapeutic applications. This study aims to summarize some of the basic characteristics of starch and cellulose derivatives related to their potential utilization as microparticulate drug carriers in the pharmaceutical field.

Preparation of aromatic β-cyclodextrin nano/microcapsules and corresponding aromatic textiles: A review

Fragrance finishing of textiles is receiving substantial interest, with aromatherapy being one of the most popular aspects of personal health care. However, the longevity of aroma on textiles and presence after subsequent launderings are major concerns for aromatic textiles directly loaded with essential oils. These drawbacks can be weakened by incorporating essential oil-complexed β-cyclodextrins (β-CDs) onto various textiles. This article reviews various preparation methods of aromatic β-cyclodextrin nano/microcapsules, as well as a wide variety of methods for the preparation of aromatic textiles based on them before and after forming, proposing future trends in preparation processes. The review also covers the complexation of β-CDs with essential oils, and the application of aromatic textiles based on β-CD nano/microcapsules. Systematic research on the preparation of aromatic textiles facilitates the realization of green and simple industrialized large-scale production, providing needed application potential in the fields of various functional materials.

Preparation and characterization of inclusion complex of Myristica fragrans Houtt. (nutmeg) essential oil with 2-hydroxypropyl-β-cyclodextrin

Nutmeg essential oil (NEO) is a natural condimentwith versatile biological activities. However, the application of NEO in food has several limitations due to its poor stability and low aqueous solubility. To overcome the shortcomings, this paper focused on the preparation of the inclusion complex (IC) of NEO with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) by the coprecipitation method. The optimal condition was inclusion temperature 36 ℃, time 247 min, stirring speed 520 r/min, and wall-core ratio 12:1, resulting in a recovery of 80.63%. The formation of IC was verified by various methods such as scanning electron microscopy, Fourier transform infrared spectroscopy and nuclear magnetic resonance. The improvement of thermal stability, antioxidant, and nitrite scavenging activities of NEO after encapsulation was proven. Moreover, the controlled release of NEO from IC can be implemented by regulating the temperature and relative humidity. Overall, NEO/HP-β-CD IC has great application potential in food industries.

Current Status of Quantum Chemical Studies of Cyclodextrin Host-Guest Complexes

This article aims to review the application of various quantum chemical methods (semi-empirical, density functional theory (DFT), second order Møller-Plesset perturbation theory (MP2)) in the studies of cyclodextrin host-guest complexes. The details of applied approaches such as functionals, basis sets, dispersion corrections or solvent treatment methods are analyzed, pointing to the best possible options for such theoretical studies. Apart from reviewing the ways that the computations are usually performed, the reasons for such studies are presented and discussed. The successful applications of theoretical calculations are not limited to the determination of stable conformations but also include the prediction of thermodynamic properties as well as UV-Vis, IR, and NMR spectra. It has been shown that quantum chemical calculations, when applied to the studies of CD complexes, can provide results unobtainable by any other methods, both experimental and computational.

Cyclodextrins as carriers for volatile aroma compounds: A review

Cyclodextrins (CDs) are edible and biocompatible natural cyclic compounds that can encapsulate essential oils, flavours, volatile aroma compounds, and other substances. Complexation with CD-based materials improves the solubility and stability of volatile compounds and protects the bioactivity of the core materials. Therefore, the development of CD/volatile compound nanosystems is a key research area in the food, cosmetic, and pharmaceutical industries. This review briefly introduces the main types of natural CD; preparation methods of CD-based materials as carriers for aromatic substances or essential oils; characterisation methods used to calculate the interaction between CDs and volatile aroma compounds; molecular docking and simulation methods; and the application of CD-based nanosystems in different industries. The review aims to provide guidance for relevant practitioners in selecting appropriate CD materials and characterisation methods.

Microcapsules based on octenyl succinic anhydride (OSA)-modified starch and maltodextrins changing the composition and release property of rose essential oil

Octenyl succinic anhydride (OSA)-modified starch and maltodextrins (MDs) are important carbohydrate polymers as wall materials. However, few studies have shown whether these two wall materials affect the composition of core materials. In this work, we investigated the effects of OSA-modified starch and MD on the release property of essential oils. Results showed that among the seven characteristic aroma components (CACs) of rose essential oil (REO), the esters released the fastest, followed by the alcohols, while the release of the phenols was the slowest. Environmental factors such as temperature and relative humidities (RHs) had significant influences on the release kinetics of CACs in REO. This work provides new insights into the use of OSA-modified starch and MDs as wall materials for encapsulating complex and bioactive components.

Microspheres of essential oil in polylactic acid and poly(methyl methacrylate) matrices and their blends

This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains. The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5-9.5 µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10 ± 10.0 wt. % for PLA system and 76.0 ± 3.3 wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same.