Injectable Hydrogels Including Magnetic Nanosheets for Multidisciplinary Treatment of Hepatocellular Carcinoma via Magnetic Hyperthermia

External stimuli-driven catalytic hydrogels for biomedical applications

Hydrogels, bearing three-dimensional networks formed through chemical or physical crosslinking of hydrophilic macromolecules, benefit from their biocompatibility, tunable properties, and high loading capacities, and thus hold great promise for biomedical applications. Recent advancements have increasingly focused on the integration of non-invasive external stimuli-such as light, heat, electricity, magnetism, and ultrasound-into hydrogel design. These external stimuli-driven catalytic hydrogels can dynamically respond to these stimuli, allowing for high spatial and temporal precision in their application. This capability enables in situ activation, controlled degradation, and catalytic reactions, making them ideal for next-generation clinical interventions. This review discusses the design strategies for external stimuli-driven catalytic hydrogels, concentrating on essential mechanisms of catalytic processes aimed at optimizing therapeutic efficacy. The discussion highlights the importance of precise control over the chemical and physical properties of hydrogels in response to specific stimuli, elucidating the regulatory mechanisms that dictate hydrogel behavior and deepening the understanding of their applications with enhanced spatial and temporal resolution.

Minimalistic Implant for Percutaneous Magnetic Hyperthermia-Based Combination Therapy of Hepatocellular Carcinoma

Percutaneous local thermal therapy, containing radio frequency and microwave ablation, is widely utilized in the clinical management of hepatocellular carcinoma (HCC) due to its minimal invasiveness and favorable therapeutic outcomes. However, its further development is limited by a prolonged ablation duration and the risk of excessive heating. Magnetic hyperthermia therapy (MHT) provides a new perspective for percutaneous tumor thermal ablation due to its superior tissue penetration capability and safety. Herein, an iron foam-agarose gel-drug (IF-Aga-drug) implant is prepared using a minimalistic method for percutaneous combination therapy of HCC. The excellent conductivity of IF endows it with strong heating capability owing to eddy current loss in an alternating magnetic field (AMF), while the abundant pores provide ample space for drug loading. Agarose gel imparts the IF platform with universal and efficient drug-loading capacity and controlled drug-release capability that is responsive to magnetic hyperthermia. Doxorubicin (DOX) is utilized as a representative drug to construct the IF-Aga-DOX implant, which is successfully employed in ultrasound-guided, magnetic hyperthermia-based combination chemotherapy for orthotopic HCC in rabbits under ultralow-power magnetic field intensities (Happl·fappl = 2.25 × 108 A m-1 s-1). The developed IF-Aga-drug implant platform offers a convenient and versatile strategy for percutaneous tumor therapy.

In Situ Fabrication of Electrospun Magnetic Film under Laparoscopic Guidance for Preventing Postoperative Recurrence of Hepatocellular Carcinoma

Despite laparoscopic-guided minimally invasive hepatectomy emerging as the primary approach for resecting hepatocellular carcinoma (HCC), there is still a significant gap in suitable biomaterials that seamlessly integrate with these techniques to achieve effective hemostasis and suppress residual tumors at the surgical margin. Electrospun films are increasingly used for wound closure, yet the employment of prefabricated electrospun films for hemostasis during minimally invasive HCC resection is hindered by prolonged operation times, complexity in implementation, limited visibility during surgery, and inadequate postoperative prevention of HCC recurrence. In this study, montmorillonite-iron oxide sheets are integrated into the polyvinylpyrrolidone (PVP) polymer framework, enhancing the resulting electrospun PVP/montmorillonite-iron oxide (MI) film (abbreviated as PMI) with robustness, hemostatic capability, and magnetocaloric properties. In contrast to the in vitro prefabricated electrospun films, the electrospun PMI film is designed to be formed in situ on liver wounds under laparoscopic guidance during hepatectomy. This design affords superior wound adaptability, facilitating meticulous wound closure and expeditious hemostasis, thereby simplifying the operative process and ultimately alleviating the workload of healthcare professionals. Moreover, when exposed to an alternating magnetic field, the film can efficiently ablate residual tumors, significantly augmenting the treatment efficacy of HCC.

Injectable Magnetic Hydrogel Incorporated with Anti-Inflammatory Peptide for Efficient Magnetothermal Treatment of Endometriosis

Endometriosis is a prevalent gynecological condition characterized by chronic pelvic pain, dysmenorrhea, and infertility, affecting ≈176 million women of reproductive age worldwide. Current treatments, including pharmacological and surgical interventions, are often associated with significant side effects and high recurrence rates. Consequently, there is an urgent need for innovative and safer therapeutic approaches. In this study, an injectable magnetic hydrogel nanosystem is developed designed for the dual-purpose magnetothermal and anti-inflammatory treatment of endometriosis. This hydrogel incorporates Fe3O4 nanoparticles alongside an anti-inflammatory peptide. Upon magnetic activation, the Fe3O4 nanoparticles induce a localized hyperthermic response, raising the temperature of endometriotic lesions to 63.3 °C, effectively destroying endometriotic cells. Concurrently, the thermally responsive hydrogel facilitates the controlled release of the anti-inflammatory peptide, thus modulating the inflammatory milieu. The biocompatibility and complete in vivo degradability of the hydrogel further enhance its therapeutic potential. The in vivo studies demonstrated that this injectable magnetic hydrogel system achieved a 90% reduction in the volume of endometriotic lesions and significantly decreased inflammatory markers, offering a promising non-invasive treatment modality for endometriosis. By integrating precise lesion ablation with the modulation of the inflammatory microenvironment, this system represents a novel approach to the clinical management of endometriosis.

Recent advances on thermosensitive hydrogels-mediated precision therapy

Precision therapy has become the preferred choice attributed to the optimal drug concentration in target sites, increased therapeutic efficacy, and reduced adverse effects. Over the past few years, sprayable or injectable thermosensitive hydrogels have exhibited high therapeutic potential. These can be applied as cell-growing scaffolds or drug-releasing reservoirs by simply mixing in a free-flowing sol phase at room temperature. Inspired by their unique properties, thermosensitive hydrogels have been widely applied as drug delivery and treatment platforms for precision medicine. In this review, the state-of-the-art developments in thermosensitive hydrogels for precision therapy are investigated, which covers from the thermo-gelling mechanisms and main components to biomedical applications, including wound healing, anti-tumor activity, osteogenesis, and periodontal, sinonasal and ophthalmic diseases. The most promising applications and trends of thermosensitive hydrogels for precision therapy are also discussed in light of their unique features.

Progress in injectable hydrogels for the treatment of incompressible bleeding: an update

Uncontrollable haemorrhage from deep, noncompressible wounds remains a persistent and intractable challenge, accounting for a very high proportion of deaths in both war and disaster situations. Recently, injectable hydrogels have been increasingly studied as potential haemostatic materials, highlighting their enormous potential for the management of noncompressible haemorrhages. In this review, we summarize haemostatic mechanisms, commonly used clinical haemostatic methods, and the research progress on injectable haemostatic hydrogels. We emphasize the current status of injectable hydrogels as haemostatic materials, including their physical and chemical properties, design strategy, haemostatic mechanisms, and application in various types of wounds. We discuss the advantages and disadvantages of injectable hydrogels as haemostatic materials, as well as the opportunities and challenges involved. Finally, we propose cutting-edge research avenues to address these challenges and opportunities, including the combination of injectable hydrogels with advanced materials and innovative strategies to increase their biocompatibility and tune their degradation profile. Surface modifications for promoting cell adhesion and proliferation, as well as the delivery of growth factors or other biologics for optimal wound healing, are also suggested. We believe that this paper will inform researchers about the current status of the use of injectable haemostatic hydrogels for noncompressible haemorrhage and spark new ideas for those striving to propel this field forward.