Progress in Polymer Science最新文献

In the last decades, nanoscale drug delivery systems have gained great attention partly due to their ability to improve the bioavailability of water insoluble drugs. To this end, the general aim in developing nanomedicine is to enhance efficacy, drug stability and drug safety profile ideally by an active- or passive-cell specific targeting effect. Alteration of dose-response and potential personalization might be future trademarks of nanomedicine. Macromolecular prodrugs (MPDs) represent a sub-class of polymer-drug conjugates featuring a degradable linkage between a macromolecule and a drug. MPDs are in particular interesting due to their capability to prolong blood circulation and to reduce side effects caused by minimized premature drug leakage. The maximum drug loading capacity is another advantage of MPDs over conventional nanomedicines. The chemical accessibility of drug conjugates and polymer carrier materials as well as recent developments in the MPD design of the last five years are summarized in this review article.

The "Janus" feature/structure inspired by the ancient Roman double-sided protector is prominent in the field of materials science due to its unique "asymmetric" concept and flexible and adjustable characteristics. The emergence of numerous biomaterials based on Janus properties/structures provides a different approach to material design for complex biomedical scenarios. Gel materials with excellent water absorption, flexibility and biocompatibility in various biomedical applications have greatly increased, and the structural design and functional integration of gels have reached some bottleneck. The Janus properties/structures completely subvert the traditional concept of "homogeneous gel" and break the limitation of "two-sided consistency" in biomedical gels. The concept of "two-sided asymmetry" led by "Adhesion-antiadhesion properties" and "hydrophilic-hydrophobic properties" has emerged and expanded the broad biomedical application prospects of Janus gels. In this review, we first summarize the various structural characteristics of Janus gel materials and the preparation technology of these gels, and explore the secret behind Janus structures from the raw materials and design concepts. Secondly, different kinds of asymmetries, including “hydrophilic-hydrophobic properties”, “Adhesion-antiadhesion properties”, structural heterogeneity and other unusual asymmetry, are discussed to show the relationship between Janus characteristics and structure. The applications of advanced Janus gels in biomedical fields such as tissue repair, anti-adhesion, substance delivery, hemostasis and human activity sensing are emphatically reviewed. In addition, the latest challenges and possible future direction of Janus gel are proposed.

A mechanical bond serves as a distinctive approach for harnessing the most beneficial features of both covalent and supramolecular chemistries, offering stability and structural adaptability owing to its unique dynamic nature. Molecules formed by mechanical bonding, known as mechanically interlocked molecules (MIMs) including catenanes, rotaxanes, and knots have opened new possibilities. Notably, the introduction of mechanically interlocked structures into polymers has led to the emergence of novel polymeric materials referred to as mechanically interlocked polymers (MIPs), such as polyrotaxanes and polycatenanes. The interlocked nature of these architectures can lead to particular conformational freedom and high mobility of their components, resulting in exceptional properties, such as ultra-stretchability, toughness, and immediate recoverability. These properties have found potential applications in diverse fields, including the development of tough hydrogels, scratch-resistant coatings, smart actuators, and batteries. Recent years have witnessed a surge in the synthesis and investigation of a diverse array of rotaxane-based MIPs, an essential class that has enabled researchers to begin grasping the impact of incorporating mechanical bonds within polymer structures, and of their mobility, on material properties. In this review, an overview of the dynamics of ring-containing polymers is presented. The review encompasses macromolecular rotaxanes, polyrotaxanes, and slide-ring networks, including the role of ring mobility in shaping the dynamics and properties of rotaxane polymers.

Polycatechols are a class of polymers bearing multiple catechol moieties. These polymers possess unique physiochemical properties such as antioxidant, bioadhesive, metal chelating, and dynamic covalent bonding. As a result, polycatechols have shown great promise in various biomedical applications i.e. drug delivery, gene and protein delivery, free radical scavenging, antimicrobials, bio-adhesions, tissue engineering, and bioimaging. The polymers have strong binding affinities with biomolecules such as genes, proteins, phospholipids, and extracellular matrices via non-covalent interactions, and are proposed as effective carriers for biotherapy and bioadhesives for tissue engineering. The abundant catechol moieties on polycatechols allow strong free radical scavenging to treat oxidative stress and inflammation. In addition, polycatechols form dynamic covalent linkages with boronate ligands, and are used to modulate the quorum-sensing signaling in bacteria, or deliver anticancer drug bortezomib to tumor microenvironments. Besides, polycatechols coordinate with metal ions such as gadolinium (III) to provide contrast reagents for magnetic resonance imaging. In this critical review, currently developed synthetic methods for polycatechols and their physiochemical properties will be introduced. The design principles for polycatechols in detailed biomedical applications will be intensively described. Finally, current challenges and future perspectives in the development of next-generation polycatechols will be discussed.

Over the past decades, there has been a flourishing of phase-separated polymer gels. Unlike traditional design methods that rely on chemical structure and polymer network construction, phase separation enables polymers to tune morphologies across the microscopic, mesoscopic, and macroscopic levels, thereby creating a new path for regulating and innovating the performance of polymer gels. This comprehensive review offers a deep dive into the mechanisms underlying phase separation formation in polymer gels and makes a particular focus on the methods used to induce phase separation in polymer gels. Additionally, the review highlights the potential performance improvements and innovations of polymer gels based on phase separation and explores the promising applications of phase separation polymers in various fields. Finally, this review emphasizes the potential benefits yet significant challenges associated with phase-separated polymer gels. The versatility and multi-scale applicability of this approach make it a promising pathway for developing cutting-edge materials with tailored properties and functionalities.

Converting lignin into useful colloidal entities with uniform size and shape offers exciting opportunities for utilization; however, this endeavor requires overcoming challenges caused by structural heterogeneity and gaining further understanding to exploit its unique functional possibilities. Still, colloidal lignin has already provided new insights into bio-polymeric materials and has triggered various innovative applications that have inspired the scientific community. This review aims to provide a comprehensive discussion of the current understanding of colloidal lignin and its emergent applications. First, a fundamental overview of lignin, including its chemistry and processing is provided. Subsequently, a multitude of technical routes to tune the properties of colloidal lignin using nano-/micro-fabrication approaches to control macroscale properties is presented. Thereafter, examples of innovative material technologies based on colloidal lignin in areas such as pollution remediation, polymeric materials, macromolecular materials, and drug delivery are given. Finally, open challenges and suggestions for future research will be discussed to guide future research to rationally expand the portfolio of promising lignin-based technologies.

The pursuit of achieving both ceramic-like hardness and polymer-like flexibility in a coating, known as a polymer–ceramic hybrid coating, is a challenging yet highly desirable goal. The application of these coatings spans various domains such as foldable displays, wearable devices, maritime industries, and biomedical engineering. Particularly, endowing polymer–ceramic hybrid coatings with functions such as transparency, anti-liquid adhesion, anti-biofouling, and self-healing expand their potential in fields necessitating highly protective performance, which have gained significant attention in recent years. In this comprehensive review, our main objective is to provide interested readers with a clear framework for assessment and future exploration of this topic. We systematically outline the fundamentals of functional polymer-ceramic hybrid coatings, explaining their fabrication intricacies. Additionally, we explore their practical applications, intricately tailored to the unique requirements of each field. Concluding our review, we address the key challenges facing modern functional polymer–ceramic coatings and propose potential paths for future advancements.

Liquid crystal elastomers (LCEs) have long held significant promise as materials for artificial muscles and smart actuators. Recent advancements in this field have introduced innovative LCE structures at various scales, resulting in novel properties and functionalities that further accentuate their actuation advantages, bolstering their potential as future soft actuation systems. The ongoing pursuit of enhanced performance and functionality in LCE actuators, essential for advancing them towards superior material-based machines and devices, is intricately linked to the understanding of the fundamental structure-property-function relationships. This review provides a perspective on these relationships across multiple structural levels, encompassing chemical structures, mesophase structures, and micro-to-macroscale programmed structures. It delves into the impact of various LCE structures on key actuation-related properties, actuation features, and functionalities. This review aspires to provide valuable insights into the design of high-performance LCE actuators, the development of exceptional actuation modes and behaviors, and the expansion of achievable functionality.

Coacervation is a liquid-liquid phase separation phenomenon. It involves the formation of a dense coacervate phase, rich in concentrated materials, and a co-existing immiscible dilute supernatant. This phenomenon can occur either from a homogeneous aqueous solution (simple coacervation) or when two different macromolecular aqueous solutions (proteins, polymers, and colloids) are brought into contact (complex coacervation). Coacervation has historical significance as it may have played a role in the origin of life, concentrating nutritious materials through liquid-liquid phase separation. It also reveals the underlying mechanisms of many biological phenomena such as intracellular biomolecular condensates, extracellular matrices, squid beak's gradient properties, sessile organism's wet adhesion, Alzheimer's diseases, and more. Coacervation provides insights and inspires promising solutions in areas like artificial cells/tissues, gradient materials, gene/drug delivery, underwater adhesives, and beyond. The driving forces of coacervation are noncovalent molecular interactions, often referred to as ‘chemistry beyond the molecule’, including hydrophobic interaction, electrostatic interaction, hydrogen-bonding interaction, cation-π interaction, π-π interaction, multivalency, etc. In this work, we have systematically reviewed the underlying noncovalent molecular interactions of simple coacervation and complex coacervation, respectively. We summarize commonly used materials and their corresponding molecular structures, discussing their applications. Some remaining challenge issues and perspectives for future studies are also presented. Understanding the underlying noncovalent molecular interactions of coacervation, alongside insights into molecular compositions and structures, can better guide the design of novel materials, elucidate various biological phenomena, and contribute to the development and optimization of relevant engineering technologies.

Structural characterization of polymer materials is a major step in the process of creating materials' design-structural-property relationships. With growing interests in artificial intelligence (AI)-driven materials design and high-throughput synthesis and measurements, there is now a critical need for development of complementary data-driven approaches (e.g., machine learning models and workflows) to enable fast and automated interpretation of the characterization results. This review sets out with a description of the needs for machine learning specifically in the context of three commonly used structural characterization techniques for polymer materials: microscopy, scattering, and spectroscopy. Subsequently, a review of notable work done on development and application of machine learning models / workflows for these three types of measurements is provided. Definitions are provided for common machine learning terms to help readers who may be less familiar with the terminologies used in the context of machine learning. Finally, a perspective on the current challenges and potential opportunities to successfully integrate such data-driven methods in parallel/sequentially with the measurements is provided. The need for innovative interdisciplinary training programs for researchers regardless of their career path/employment in academia, national laboratories, or research and development in industry is highlighted as a strategy to overcome the challenge associated with the sharing and curation of data and unifying metadata.