Injectable Bioadhesive Hydrogels Scavenging ROS and Restoring Mucosal Barrier for Enhanced Ulcerative Colitis Therapy

Marine polysaccharides hydrogel with encapsulated mesalazine for the treatment of ulcerative colitis: Integrative effects on inflammation, microbiota, and mucosal repair

Ulcerative colitis is a chronic non-specific inflammatory disease of the intestine that significantly impacts patient quality of life. This study introduces a OF/CC/SM hydrogel containing oxidized fucoidan (OF), carboxymethyl chitosan (CC), and silk sericin-stabilized mesalazine (SM), designed for rectal administration to target mesalazine delivery specifically to the colon. The OF/CC/SM hydrogel demonstrated good biocompatibility (cell compatibility > 99 %), injectability, and adhesion strength, ensuring effective mesalazine retention and release. In vitro assays confirmed the hydrogel's antioxidant and anti-inflammatory properties, which were further validated in vivo using a mouse model of ulcerative colitis. Rectal administration of OF/CC/SM hydrogel significantly relieved weight loss, lowered disease activity index scores, and prevented intestinal shortening associated with dextran sulfate sodium (DSS) treatment. The hydrogel decreased the expression of proinflammatory cytokines (e.g., tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β)), while normalized the level of biomarkers (e.g., inducible nitric oxide synthase (iNOS), myeloperoxidase (MPO), catalase (CAT), and malondialdehyde (MDA)). Additionally, the OF/CC/SM hydrogel modulated the gut microbiota, increasing beneficial bacteria while decreasing potentially harmful species. Histopathological analysis revealed a reduction in inflammatory infiltration and improved mucosal architecture. Additionally, in vivo imaging studies confirmed sustained presence of OF/CC/SM hydrogel in the intestines following rectal administration, highlighting its potential for enhanced therapeutic efficacy in treating ulcerative colitis.

Effect of hydrogel drug delivery system for treating ulcerative colitis: A preclinical meta-analysis

Hydrogel drug delivery systems (DDSs) for treating ulcerative colitis (UC) have garnered attention. However, there is a lack of meta-analysis summarizing their effectiveness. Therefore, this study aimed to conduct a meta-analysis of pre-clinical evidence comparing hydrogel DDSs with free drug administration. Subgroup analyses were performed based on hydrogel materials (polysaccharide versus non-polysaccharide) and administration routes of the hydrogel DDSs (rectal versus oral). The outcome indicators included colon length, histological scores, tumor necrosis factor-α (TNF-α), zonula occludens protein 1(ZO-1), and area under the curve (AUC). The results confirmed the therapeutic enhancement of the hydrogel DDSs for UC compared with the free drug group. Notably, no significant differences were found between polysaccharide and non-polysaccharide materials, however, oral administration was found superior regarding TNF-α and AUC. In conclusion, oral hydrogel DDSs can serve as potential excellent dosage forms in oral colon -targeting DDSs, and in the design of colon hydrogel delivery systems, polysaccharides do not show advantages compared with other materials.

Bionic double-crosslinked hydrogel of poly (γ-glutamic acid)/poly (N-(2-hydroxyethyl) acrylamide) with ultrafast gelling process and ultrahigh burst pressure for emergency rescue

Injectable adhesive hydrogels combining rapid gelling with robust adhesion to wet tissues are highly required for fast hemostasis in surgical and major trauma scenarios. Inspired by the cross-linking mechanism of mussel adhesion proteins, we developed a bionic double-crosslinked (BDC) hydrogel of poly (γ-glutamic acid) (PGA)/poly (N-(2-hydroxyethyl) acrylamide) (PHEA) fabricated through a combination of photo-initiated radical polymerization and hydrogen bonding cross-linking. The BDC hydrogel exhibited an ultrafast gelling process within 1 s. Its maximum adhesion strength to wet porcine skin reached 254.5 kPa (9 times higher than that of cyanoacrylate (CA) glue) and could withstand an ultrahigh burst pressure of 626.4 mmHg (24 times higher than that of CA glue). Notably, the BDC hydrogel could stop bleeding within 10 s from a rat liver incision 10 mm long and 5 mm deep. The wound treated with the BDC hydrogel healed faster than the control groups, underlining the potential for emergency rescue and wound care scenarios.

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.

Systemic platelet inhibition with localized chemotherapy by an injectable ROS-scavenging gel against postsurgical breast cancer recurrence and metastasis

Early solid tumors benefit from surgical resection, but residual stubborn microtumors, pro-inflammatory microenvironment and activated platelets at the postoperative wound site are prone to recurrence and metastasis, resulting in poor prognosis. Here, we developed a dual-pronged strategy consisting of (i) in-situ forming ROS-scavenging gels loaded with anticancer drugs at the postoperative wound site to improve the tumor microenvironment and inhibit the recurrence of residual microtumors after orthotopic surgery, and (ii) systemic administration of clopidegrol via albumin nanoparticles for inhibiting activated platelets in the circulation thus inhibiting tumor remote migration. In a mouse model of postoperative recurrence and metastasis of orthotopic 4T1 breast cancer, the dual-pronged strategy greatly inhibited postoperative orthotopic tumor recurrence and reduced lung metastasis. This work provides an effective strategy for the postoperative intervention and treatment of solid tumors to inhibit postoperative tumor recurrence and metastasis, which has the potential to improve the prognosis and survival of patients with postoperative solid tumors. STATEMENT OF SIGNIFICANCE: Early-stage solid tumors benefit from surgical resection. However, the presence of residual microtumors, pro-inflammatory tumor microenvironment, and activated platelets at the postoperative wound site lead to recurrence and metastasis, ultimately resulting in poor prognosis. Here, we have devised a dual-pronged approach that includes (i) in-situ forming ROS-scavenging gels loaded with anticancer drugs (TM@Gel) at the wound site after surgery to enhance the tumor microenvironment (TME) and hinder the reappearance of residual microtumors, and (ii) systemic administration of clopidegrol through albumin nanoparticles (HHP) for inhibiting activated platelets in the circulation thus impeding tumor distant migration. This work provides a viable option for postoperative intervention and treatment of solid tumors to suppress postoperative tumor recurrence and metastasis.

Bioadhesive and Injectable Hydrogels and Their Correlation with Mesenchymal Stem Cells Differentiation for Cartilage Repair: A Mini-Review

Injectable bioadhesive hydrogels, known for their capacity to carry substances and adaptability in processing, offer great potential across various biomedical applications. They are especially promising in minimally invasive stem cell-based therapies for treating cartilage damage. This approach harnesses readily available mesenchymal stem cells (MSCs) to differentiate into chondrocytes for cartilage regeneration. In this review, we investigate the relationship between bioadhesion and MSC differentiation. We summarize the fundamental principles of bioadhesion and discuss recent trends in bioadhesive hydrogels. Furthermore, we highlight their specific applications in conjunction with stem cells, particularly in the context of cartilage repair. The review also encompasses a discussion on testing methods for bioadhesive hydrogels and direct techniques for differentiating MSCs into hyaline cartilage chondrocytes. These approaches are explored within both clinical and laboratory settings, including the use of genetic tools. While this review offers valuable insights into the interconnected aspects of these topics, it underscores the need for further research to fully grasp the complexities of their relationship.