Janus-Inspired Core-Shell Structure Hydrogel Programmatically Releases Melatonin for Reconstruction of Postoperative Bone Tumor

A novel strategy for addressing post-surgical abdominal adhesions: Janus hydrogel

Abdominal adhesions are a frequent complication after abdominal surgery, which can cause significant pain and burden to patients. Despite various treatment options, including surgical intervention and pharmacotherapy, these often fail to consistently and effectively prevent postoperative abdominal adhesions. Janus hydrogel is famous for its asymmetric characteristics, which shows great prospects in the prevention and treatment of abdominal adhesion. This review outlines the preparation methods, mechanisms of action, and key applications of Janus hydrogel in the prevention of postoperative abdominal adhesions. Furthermore, we examine the current limitations of the Janus hydrogel anti-adhesion barrier and explore potential future directions for its development.

Melatonin-Loaded Hydrogel Modulates Circadian Rhythms and Alleviates Oxidative Stress and Inflammation to Promote Wound Healing

Circadian rhythm disruption, commonly caused by factors such as jet lag and shift work, is increasingly recognized as a critical factor impairing wound healing. Although melatonin is known to regulate circadian rhythms and has potential in wound repair, its clinical application is limited by low bioavailability. To address these challenges, we developed an alginate-based dual-network hydrogel as a delivery system for melatonin, ensuring its stable and sustained release at the wound site. This approach enhances the efficacy of melatonin in modulating the wound healing process. We investigated the effects of circadian rhythm disruption on the wound microenvironment under the influence of the melatonin-loaded hydrogel with a focus on its biocompatibility, hemostatic properties, and antioxidant response functions. Additionally, we elucidated the mechanisms by which the melatonin-loaded hydrogel system promotes wound healing. Our findings provide insights into the relationship between circadian rhythm disruption and wound healing, offering a promising strategy for the management of chronic wounds associated with circadian rhythm disorders.

Multiple-Effect Combined Hydrogels: "Temporal Regulation" Treatment of Osteosarcoma-Associated Bone Defects with Switchable Hyperthermia and Bioactive Agents

Achieving the clinically staged treatment of osteosarcoma-associated bone defects encounters the multiple challenges of promptly removing postoperative residual tumor cells and bacterial infection, followed by bone reconstruction. Herein, a core/shell hydrogel with multiple-effect combination is designed to first exert antitumor and antibacterial activities and then promote osteogenesis. Specifically, doxorubicin (DOX) is loaded by magnesium-iron-based layered double hydroxide (LDH) to prepare LDOX, which is introduced into a thermo-sensitive hydrogel to serve as an outer shell of the core/shell hydrogel, meanwhile, LDH-contained liquid crystal hydrogel, abbreviated as LCgel-L, is served as an inner core. At the early stage of treatment, the dissociation of the outer shell triggered by moderate hyperthermia led to the thermo-sensitive release of LDOX, which can be targeted for the release of DOX within tumor cells, thereby promptly removing postoperative residual tumor cells based on the synergistic effect of photothermal therapy (PTT) and DOX, and postoperative bacterial infection can also be effectively prevented by PTT simultaneously. More importantly, the dissociation of the outer shell prompted the full exposure of the inner core, which will exert osteogenic activity based on the synergy of liquid crystal hydrogel as well as LDH-induced mild hyperthermia and ion effects, thereby enabling "temporal regulation" treatment of osteosarcoma-associated bone defects. This study provides a valuable insight for the development of osteosarcoma-associated bone repair materials.

Exploring the frontiers: The potential and challenges of bioactive scaffolds in osteosarcoma treatment and bone regeneration

The standard treatment for osteosarcoma combines surgery with chemotherapy, yet it is fraught with challenges such as postoperative tumor recurrence and chemotherapy-induced side effects. Additionally, bone defects after surgery often surpass the body's regenerative ability, affecting patient recovery. Bioengineering offers a novel approach through the use of bioactive scaffolds crafted from metals, ceramics, and hydrogels for bone defect repair. However, these scaffolds are typically devoid of antitumor properties, necessitating the integration of therapeutic agents. The development of a multifunctional therapeutic platform incorporating chemotherapeutic drugs, photothermal agents (PTAs), photosensitizers (PIs), sound sensitizers (SSs), magnetic thermotherapeutic agents (MTAs), and naturally occurring antitumor compounds addresses this limitation. This platform is engineered to target osteosarcoma cells while also facilitating bone tissue repair and regeneration. This review synthesizes recent advancements in integrated bioactive scaffolds (IBSs), underscoring their dual role in combating osteosarcoma and enhancing bone regeneration. We also examine the current limitations of IBSs and propose future research trajectories to overcome these hurdles.

Recent advances of injectable in situ-forming hydrogels for preventing postoperative tumor recurrence

The unavoidable residual tumor tissue from surgery and the strong aggressiveness of tumor cells pose challenges to the postoperative treatment of tumor patients, accompanied by in situ tumor recurrence and decreased quality of life. Therefore, there is an urgent need to explore appropriate postoperative therapeutic strategies to remove residual tumor cells after surgery to inhibit tumor recurrence and metastasis after surgery. In recent years, with the rapid development of biomedical materials, the study of local delivery systems as postoperative delivery of therapeutic agents has gradually attracted the attention of researchers. Injectable in situ-forming hydrogel is a locally administered agent injected in situ as a solution that can be loaded with various therapeutic agents and rapidly gels to form a semi-solid gel at the treatment site. This type of hydrogel tightly fills the surgical site and covers irregular excision surfaces. In this paper, we review the recent advances in the application of injectable in situ-forming hydrogels in postoperative therapy, focusing on the matrix materials of this type of hydrogel and its application in the postoperative treatment of different types of tumors, as well as discussing the challenges and prospects of its clinical application.

Janus structure hydrogels: recent advances in synthetic strategies, biomedical microstructure and (bio)applications

Janus structure hydrogels (JSHs) are novel materials. Their primary fabrication methods and various applications have been widely reported. JSHs are primarily composed of Janus particles (JNPs) and polysaccharide components. They exhibit two distinct physical or chemical properties, generating intriguing characteristics due to their asymmetric structure. Normally, one side (adhesive interface) is predominantly constituted of polysaccharide components, primarily serving excellent adhesion. On the other side (functional surface), they integrate diverse functionalities, concurrently performing a plethora of synergistic functions. In the biomedical field, JSHs are widely applied in anti-adhesion, drug delivery, wound healing, and other areas. It also exhibits functions in seawater desalination and motion sensing. Thus, JSHs hold broad prospects for applications, and they possess significant research value in nanotechnology, environmental science, healthcare, and other fields. Additionally, this article proposes the challenges and future work facing these fields.

Innovative Biomaterials for Bone Tumor Treatment and Regeneration: Tackling Postoperative Challenges and Charting the Path Forward

Surgical resection of bone tumors is the primary approach employed in the treatment of bone cancer. Simultaneously, perioperative interventions, particularly postoperative adjuvant anticancer strategies, play a crucial role in achieving satisfactory therapeutic outcomes. However, the occurrence of postoperative bone tumor recurrence, metastasis, extensive bone defects, and infection are significant risks that can result in unfavorable prognoses or even treatment failure. In recent years, there has been significant progress in the development of biomaterials, leading to the emergence of new treatment options for bone tumor therapy and bone regeneration. This progress report aims to comprehensively analyze the strategic development of unique therapeutic biomaterials with inherent healing properties and bioactive capabilities for bone tissue regeneration. These composite biomaterials, classified into metallic, inorganic non-metallic, and organic types, are thoroughly investigated for their responses to external stimuli such as light or magnetic fields, internal interventions including chemotherapy or catalytic therapy, and combination therapy, as well as their role in bone regeneration. Additionally, an overview of self-healing materials for osteogenesis is provided and their potential applications in combating osteosarcoma and promoting bone formation are explored. Furthermore, the safety concerns of integrated materials and current limitations are addressed, while also discussing the challenges and future prospects.

3D Bioprinted Tumor-Stroma Models of Triple-Negative Breast Cancer Stem Cells for Preclinical Targeted Therapy Evaluation

Breast cancer stem cells (CSCs) play a pivotal role in therapy resistance and tumor relapse, emphasizing the need for reliable in vitro models that recapitulate the complexity of the CSC tumor microenvironment to accelerate drug discovery. We present a bioprinted breast CSC tumor-stroma model incorporating triple-negative breast CSCs (TNB-CSCs) and stromal cells (human breast fibroblasts), within a breast-derived decellularized extracellular matrix bioink. Comparison of molecular signatures in this model with different clinical subtypes of bioprinted tumor-stroma models unveils a unique molecular profile for artificial CSC tumor models. We additionally demonstrate that the model can recapitulate the invasive potential of TNB-CSC. Surface-enhanced Raman scattering imaging allowed us to monitor the invasive potential of tumor cells in deep z-axis planes, thereby overcoming the depth-imaging limitations of confocal fluorescence microscopy. As a proof-of-concept application, we conducted high-throughput drug testing analysis to assess the efficacy of CSC-targeted therapy in combination with conventional chemotherapeutic compounds. The results highlight the usefulness of tumor-stroma models as a promising drug-screening platform, providing insights into therapeutic efficacy against CSC populations resistant to conventional therapies.

Janus hydrogels: merging boundaries in tissue engineering for enhanced biomaterials and regenerative therapies

In recent years, the design and synthesis of Janus hydrogels have witnessed a thriving development, overcoming the limitations of single-performance materials and expanding their potential applications in tissue engineering and regenerative medicine. Janus hydrogels, with their exceptional mechanical properties and excellent biocompatibility, have emerged as promising candidates for various biomedical applications, including tissue engineering and regenerative therapies. In this review, we present the latest progress in the synthesis of Janus hydrogels using commonly employed preparation methods. We elucidate the surface and interface interactions of these hydrogels and discuss the enhanced properties bestowed by the unique "Janus" structure in biomaterials. Additionally, we explore the applications of Janus hydrogels in facilitating regenerative therapies, such as drug delivery, wound healing, tissue engineering, and biosensing. Furthermore, we analyze the challenges and future trends associated with the utilization of Janus hydrogels in biomedical applications.