Applications of Biopolymers for Drugs and Probiotics Delivery

Research regarding the use of biopolymers has been of great interest to scientists, the medical community, and the industry especially in recent years. Initially used for food applications, the special properties extended their use to the pharmaceutical and medical industries. The practical applications of natural drug encapsulation materials have emerged as a result of the benefits of the use of biopolymers as edible coatings and films in the food industry. This review highlights the use of polysaccharides in the pharmaceutical industries and as encapsulation materials for controlled drug delivery systems including probiotics, focusing on their development, various applications, and benefits. The paper provides evidence in support of research studying the use of biopolymers in the development of new drug delivery systems, explores the challenges and limitations in integrating polymer-derived materials with product delivery optimization, and examines the host biological/metabolic parameters that can be used in the development of new applications.

Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions

In this review, we describe the recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities, some of which have not been observed in or achieved by biological systems. In addition, a brief historical overview of the helical assemblies of small molecules and remarkable progress in the synthesis of single-stranded and multistranded helical foldamers and polymers, their properties, structures, and functions, mainly since 2009, will also be described.

Double-stranded polymeric ladderphanes

Double-stranded polymeric ladderphanes are obtained by ring-opening metathesis polymerization (ROMP) of bisnorbornene derivatives by the first generation of Grubbs catalyst (G-I). A range of two- and three-dimensional organic and organometallic linkers are used to connect two norbornene units. The structures of these double-stranded polymers are proved by spectroscopic means and scanning tunneling microscopic (STM) images. Hydrolytic cleavages of these ladderphanes give the corresponding single-stranded polymers with the same degree of polymerization and polydispersity as those of the double-stranded counterparts. Helical polymeric ladderphanes are also synthesized similarly when chiral linkers are used. Strong intereactions between adjacent linkers have been revealed by their physical properties in these polymers. Chemical modification of ladderphanes is achieved by bis-dihydroxylation, diimide reduction of double bonds, and electrochemical oxidation of linkers. Unsymmetrical ladderphanes with well-defined lengths and narrow dispersity are also obtained by replication and by sequential polymerization.