Configurational Entropy-Enabled Thermostability of Cell Membranes in Extremophiles: From Molecular Mechanism to Bioinspired Design

Topologically Engineered Supramolecular Cyclolipid Nanoparticles: A Custom-Tailored Delivery System for Inhaled Combination Therapy

Lipid nanoparticles (LNPs) have shown promising potential in the development of nucleic acid therapeutics and vaccines; however, unsatisfactory endosomal escape efficiency and physiological stability hinder their clinical applications. Herein, we design and synthesize a novel topologically engineered cyclodextrin-cored lipid (cyclolipid) featuring seven tertiary amine groups, seven secondary amine groups, and 14 hydrophobic alkyl tails to fabricate two-component supramolecular cyclolipid nanoparticles (CNPs). Benefiting from its cone-shaped structure, the cyclolipid facilitates the transition of endosomal membranes from the lamellar phase to the unstable hexagonal II phase, thereby promoting membrane destabilization and endosomal escape of CNPs. Additionally, the high density of ionizable sites enhances the binding capacity with RNA, while multiple hydrophobic alkyl chains strengthen the stability of CNPs, thus guaranteeing the in vivo circulation stability. Interestingly, the cavity of the cyclolipid enables the encapsulation of pirfenidone (PFD, an antifibrotic drug) through host-guest interactions, offering a promising strategy for synergistic therapy. Rationally optimizing the components and physicochemical properties of CNPs dramatically promotes mucus penetration capability, thereby enhancing their bioavailability in the lungs and avoiding unwanted side effects toward other organs. Leveraging their exceptional ability for achieving physiological stability, mucus penetration, and endosomal escape, siRNA targeting heat shock protein 47 (siHsp47) and PFD are codelivered by CNPs (CNPs@siHsp47/PFD) for the treatment of pulmonary fibrosis. CNPs@siHsp47/PFD synergistically alleviates pulmonary fibrosis, achieving therapeutic outcomes comparable to those of healthy mice, highlighting the outstanding potential of CNPs as the next-generation delivery platform for drug and gene combination therapy.

Self-Assembly at Curved Biointerfaces

Most of the biological interfaces are curved. Understanding the organizational structures and interaction patterns at such curved biointerfaces is therefore crucial not only for deepening our comprehension of the principles that govern life processes but also for designing and developing targeted drugs aimed at diseased cells and tissues. Despite the considerable efforts dedicated to this area of research, our understanding of curved biological interfaces is still limited. Many aspects of these interfaces remain elusive, presenting both challenges and opportunities for further exploration. In this review, we summarize the structural characteristics of biological interfaces found in nature, the current research status of materials associated with curved biointerfaces, and the theoretical advancements achieved to date. Finally, we outline future trends and challenges in the theoretical and technological development of curved biointerfaces. By addressing these challenges, people could bridge the knowledge gap and unlock the full potential of curved biointerfaces for scientific and technological advancements, ultimately benefiting various fields and improving human health and well-being.

Surface Wetting Behaviors of Hydroxyl-Terminated Polybutadiene: Molecular Mechanism and Modulation

The surface wetting or coating of materials by polymers is crucial for designing functional interfaces and various industrial applications. However, the underlying mechanisms remain elusive. In this study, the wetting behavior of hydroxyl-terminated polybutadiene (HTPB) on a quartz surface was systematically investigated using computer simulation methods. A notable tip-dominant surface adsorption mode of HTPB was identified, where the hydroxyl group at the end of the polymer chain binds to the surface to initiate the wetting process. Moreover, it was found that with the increase in the degree of polymerization (e.g., from DP = 10 to 30), spontaneous adsorption of HTPB becomes increasingly difficult, with a three-fold increase in the adsorption time. These results suggest a competition mechanism between enthalpy (e.g., adhesion between the polymer and the surface) and entropy (e.g., conformational changes in polymer chains) that underlies the wetting behavior of HTPB. Based on this mechanism, two strategies were employed: altering the degree of polymerization of HTPB and/or regulating the amount of interfacial water molecules (e.g., above or below the threshold amount of 350 on a 10 × 10 nm2 surface). These strategies effectively modulate HTPB's surface wetting process. This study provides valuable insights into the mechanisms underlying the surface adsorption behavior of HTPB and offers guidance for manipulating polymer wetting processes at interfaces.

The entropy-controlled strategy in self-assembling systems

Self-assembly of various building blocks has been considered as a powerful approach to generate novel materials with tailorable structures and optimal properties. Understanding physicochemical interactions and mechanisms related to structural formation and transitions is of essential importance for this approach. Although it is well-known that diverse forces and energies can significantly contribute to the structures and properties of self-assembling systems, the potential entropic contribution remains less well understood. The past few years have witnessed rapid progress in addressing the entropic effects on the structures, responses, and functions in the self-assembling systems, and many breakthroughs have been achieved. This review provides a framework regarding the entropy-controlled strategy of self-assembly, through which the structures and properties can be tailored by effectively tuning the entropic contribution and its interplay with the enthalpic counterpart. First, we focus on the fundamentals of entropy in thermodynamics and the entropy types that can be explored for self-assembly. Second, we discuss the rules of entropy in regulating the structural organization in self-assembly and delineate the entropic force and superentropic effect. Third, we introduce the basic principles, significance and approaches of the entropy-controlled strategy in self-assembly. Finally, we present the applications where this strategy has been employed in fields like colloids, macromolecular systems and nonequilibrium assembly. This review concludes with a discussion on future directions and future research opportunities for developing and applying the entropy-controlled strategy in complex self-assembling systems.