Chiral SiO2 and Ag@SiO2 Materials Templated by Complexes Consisting of Comblike Polyethyleneimine and Tartaric Acid.

A facile avenue to fabricate micrometer-sized chiral (L-, D-) and meso-like (dl-) SiO2 materials with unique structures by using crystalline complexes (cPEI/tart), composed of comblike polyethyleneimine (cPEI) and L-, D-, or dl-tartaric acid, respectively, as catalytic templates is reported. Interestingly, both chiral crystalline complexes appeared as regularly left- and right-twisted bundle structures about 10 µm in length and about 5 µm in diameter, whereas the dl-form occurred as circular structures with about 10 µm diameter. Subsequently, SiO2 @cPEI/tart hybrids with high silica content (>55.0 wt %) were prepared by stirring a mixture containing tetramethoxysilane (TMOS) and the aggregates of the crystalline complexes in water. The chiral SiO2 hybrids and calcined chiral SiO2 showed very strong CD signals and a nanofiber-based morphology on their surface, whereas dl-SiO2 showed no CD activity and a nanosheet-packed disklike shape. Furthermore, metallic silver nanoparticles (Ag NPs) were encapsulated in each silica hybrid to obtain chiral (D and L forms) and meso-like (dl form) Ag@SiO2 composites. Also, the reaction between L-cysteine (Lcys) and these Ag@SiO2 composites was preliminarily investigated. Only chiral L- and D-Ag@SiO2 composites promoted the reaction between Lcys and Ag NPs to produce a molecular [Ag-Lcys]n complex with remarkable exciton chirality, whereas the reaction hardly occurred in the case of meso-like (dl-) Ag@SiO2 composite.

Biomimetic synthesis of shaped and chiral silica entities templated by organic objective materials.

Organic molecules with accompanying self-organization have been a great subject in chemistry, material science and nanotechnology in the past two decades. One of the most important roles of organized organic molecules is the capability of templating complexly structured inorganic materials. The focus of this Minireview is on nanostructured silica with divergent morphologies and/or integrated chirality directed by organic templates of self-assembled polyamine/polypeptides/block copolymers, chiral organogels, self-organized chiral amphiphiles and chiral crystalline complexes, etc., by biomimetic silicification and conventional sol-gel reaction. Among them, biosilica (diatoms and sponges)-inspired biomimetic silicifications are particularly highlighted.

[Advance in studies on anti-diabetic mechanism of Gardeniae Fructus and its active ingredient geniposide].

The diabetes is mainly treated by the oral administration of western medicines at present. Despite their rapid curative effect, there have been still many reports for the western medicines about their clinical adverse reactions, failure of effective prevention and treatment of complications and drug resistance. Hence, they are not suitable for long-term administration. Traditional Chinese medicines have a long history in treating diabetes mellitus (DM) , which is commonly known as Xiaokezheng in the theory of traditional Chinese medicines. In recent years, many scholars have taken extracts from traditional Chinese medicines or separated active constituents as the study objects in the expectation of developing new-type drugs for treating and preventing diabetes. Therefore, a large number of study reports have been emerged in this field. Due to their significant glucose-reducing effect and specific effect in treating complications of diabetes, traditional Chinese medicine Gardeniae Fructus and its iridoid component geniposide shall be given full attention. This paper summarized the advance in studies on the curative effect and action mechanism of Gardeniae Fructus and geniposide in preventing and treating diabetes.

[Study on dosage form design for improving oral bioavailability of traditional Chinese medicines].

Both chemical drugs and traditional Chinese medicines have the problem of low bioavailability. However, as traditional Chinese medicines are a multi-component complex, their dosage forms are required to be designed in line with their characteristics, in order to improve the bioavailability of traditional Chinese medicines. Traditional Chinese medicines are mostly prepared into pill, powder, paste, elixir and decoction, but with such drawbacks as high administration dose and poor efficacy. With the process of modernization of traditional Chinese medicines, new-type preparations have be developed and made outstanding achievements. However, they fail to make an organic integration between traditional Chinese medicine theories and modern preparation theories. Characteristics of traditional Chinese medicines are required to be taken into account during the development of traditional Chinese medicines. In the article, multi-component preparation technology was adopted to establish a multi-component drug release system of traditional Chinese medicines on the basis of multiple components of traditional Chinese medicines.