Bioapplication of cyclodextrin-containing montmorillonite

In vitro and in vivo degradation, biocompatibility and bone repair performance of strontium-doped montmorillonite coating on Mg-Ca alloy

Poor bone growth remains a challenge for degradable bone implants. Montmorillonite and strontium were selected as the carrier and bone growth promoting elements to prepare strontium-doped montmorillonite coating on Mg-Ca alloy. The surface morphology and composition were characterized by SEM, EDS, XPS, FT-IR and XRD. The hydrogen evolution experiment and electrochemical test results showed that the Mg-Ca alloy coated with Sr-MMT coating possessed optimal corrosion resistance performance. Furthermore, in vitro studies on cell activity, ALP activity, and cell morphology confirmed that Sr-MMT coating had satisfactory biocompatibility, which can significantly avail the proliferation, differentiation, and adhesion of osteoblasts. Moreover, the results of the 90-day implantation experiment in rats indicated that, the preparation of Sr-MMT coating effectively advanced the biocompatibility and bone repair performance of Mg-Ca alloy. In addition, The Osteogenic ability of Sr-MMT coating may be due to the combined effect of the precipitation of Si4+ and Sr2+ in Sr-MMT coating and the dissolution of Mg2+ and Ca2+ during the degradation of Mg-Ca alloy. By using coating technology, this study provides a late-model strategy for biodegradable Mg alloys with good corrosion resistance, biocompatibility. This new material will bring more possibilities in bone repair.

Cyclodextrin-pillar[n]arene hybridized macrocyclic systems

Cyclodextrin (CD) and pillar[n]arene are significant macrocyclic host molecules in supramolecular chemistry, and have either similar or contrasting physicochemical properties, for example, both can provide capable cavities available for recognizing various favorite guest molecules, while they usually possess different solubility in aqueous solutions, and exhibit diverse chiral characteristics. To balance their similarity and differences inherited from each chemical structure and incorporate both advantages, the CD-pillar[n]arene hybrid macrocyclic system was recently developed. In this review, we will focus on the preparation and application of CD-pillar[n]arene hybrid macrocyclic systems. Both noncovalent interactions and covalent bonds were employed in the synthesis strategies of building the hybrid macrocyclic system, which was in the form of host-guest inclusion, self-assembly, conjugated molecules, and polymeric structures. Furthermore, the CD-pillar[n]arene hybrid macrocyclic system has been primarily applied for the removal of organic pollutants from water, induced chirality, as well as photocatalysis due to the integration of both cavities from CD and pillar[n]arene as hybrid hosts and chiral characteristics inherited from their chemical structures.