Polylactic acid film surface functionalized by zwitterionic poly[2-(methacryloyloxy)ethyl choline phosphate] with improved biocompatibility

Self-Adaptive Release of Stem Cell-Derived Exosomes from a Multifunctional Hydrogel for Accelerating MRSA-Infected Diabetic Wound Repair

Chronic diabetic wounds are prone to severe skin necrosis and bacterial infections, with elevated reactive oxygen species (ROS) and persistent inflammation further hindering the healing process. Developing smart dressings with multifunctional therapeutic capabilities to simultaneously combat infections, reduce oxidative stress, alleviate inflammation, and promote tissue regeneration remains a significant challenge. Here, we introduce a self-adaptive yet multifunctional hydrogel (Exo-Gel) designed to accelerate methicillin-resistant Staphylococcus aureus (MRSA)-infected diabetic wound repair. Exo-Gel utilizes choline phosphate (CP) groups to both anchor stem cell-derived exosomes (Exo) via electrostatic interactions and disrupt bacterial membranes, providing inherent bacteriostatic effects. Additionally, ROS-responsive thioketal (TK) linkers enable the self-adaptive release of exosomes based on local ROS levels while also scavenging excess ROS. This synergistic system facilitates wound healing by modulating oxidative stress, reducing inflammation, promoting M2 macrophage polarization, and enhancing cell proliferation, myofibroblast migration, angiogenesis, and collagen deposition to accelerate tissue regeneration. In diabetic Sprague-Dawley rats with MRSA-infected full-thickness wounds, Exo-Gel achieved remarkable bacteriostatic activity and accelerated wound healing. Exo-Gel offers a cost-effective, multifunctional, and self-adaptive therapeutic strategy for managing chronic diabetic wounds, requiring no external components or operations, making it highly practical and translatable for clinical applications.

Zwitterionic Hydrogels: From Synthetic Design to Biomedical Applications

Zwitterionic hydrogels have emerged as a highly promising class of biomaterials, attracting considerable attention due to their unique properties and diverse biomedical applications. Zwitterionic moieties, with their balanced positive and negative charges, endow hydrogels with exceptional hydration, resistance to nonspecific protein adsorption, and low immunogenicity due to their distinctive molecular structure. These properties facilitate various biomedical applications, such as medical device coatings, tissue engineering, drug delivery, and biosensing. This review explores the structure-property relationships in zwitterionic hydrogels, highlighting recent advances in their design principles, synthesis methods, structural characteristics, and biomedical applications. To meet the evolving and growing demand for the biomedical field, this review examines current challenges and explores future research directions for optimizing the multifunctional properties of zwitterionic hydrogels. As promising candidates for advanced biomaterials, zwitterionic hydrogels are poised to address critical challenges in biomedical applications, paving the way for improved therapeutic outcomes and broader applicability in healthcare.

Design, preparation, and characterization of lubricating polymer brushes for biomedical applications

The lubrication modification of biomedical devices significantly enhances the functionality of implanted interventional medical devices, thereby providing additional benefits for patients. Polymer brush coating provides a convenient and efficient method for surface modification while ensuring the preservation of the substrate's original properties. The current research has focused on a "trial and error" method to finding polymer brushes with superior lubricity qualities, which is time-consuming and expensive, as obtaining effective and long-lasting lubricity properties for polymer brushes is difficult. This review summarizes recent research advances in the biomedical field in the design, material selection, preparation, and characterization of lubricating and antifouling polymer brushes, which follow the polymer brush development process. This review begins by examining various approaches to polymer brush design, including molecular dynamics simulation and machine learning, from the fundamentals of polymer brush lubrication. Recent advancements in polymer brush design are then synthesized and potential avenues for future research are explored. Emphasis is placed on the burgeoning field of zwitterionic polymer brushes, and highlighting the broad prospects of supramolecular polymer brushes based on host-guest interactions in the field of self-repairing polymer brush applications. The review culminates by providing a summary of methodologies for characterizing the structural and functional attributes of polymer brushes. It is believed that a development approach for polymer brushes based on "design-material selection-preparation-characterization" can be created, easing the challenge of creating polymer brushes with high-performance lubricating qualities and enabling the on-demand creation of coatings. STATEMENT OF SIGNIFICANCE: Biomedical devices have severe lubrication modification needs, and surface lubrication modification by polymer brush coating is currently the most promising means. However, the design and preparation of polymer brushes often involves "iterative testing" to find polymer brushes with excellent lubrication properties, which is both time-consuming and expensive. This review proposes a polymer brush development process based on the "design-material selection-preparation-characterization" strategy and summarizes recent research advances and trends in the design, material selection, preparation, and characterization of polymer brushes. This review will help polymer brush researchers by alleviating the challenges of creating polymer brushes with high-performance lubricity and promises to enable the on-demand construction of polymer brush lubrication coatings.