Sandwich-Like Fibers/Sponge Composite Combining Chemotherapy and Hemostasis for Efficient Postoperative Prevention of Tumor Recurrence and Metastasis

One hydrophobic coating enables macro- and micro-scale blood contact activation

Efforts to develop hemostatic materials/devices have focused solely on enhanced liquid adsorption for concentrating blood components and/or new material forms for covering/sealing injured blood vessels. Considering the increasing coagulopathy conditions and versatile material forms, it is assumed to be valuable but inaccessible for creating universal hemostatic surfaces regardless of liquid-absorption property and coagulation component deficiency. Herein, we illustrate a facile polyphenol/alkyl (ATA) coating for macro-to-micro scale hemostatic materials that can integrate the virtues of contact-activation hemostatic property, low liquid-absorption property and applicability for healthy/coagulopathy conditions. Medical gauze with adequate ATA content, of highly hydrophobic surface that can reduce unnecessary blood absorption and bacterial adhesion at wounds, possesses the significantly higher hemostatic property than the pristine gauze. Macro-scale dressings/sheets and micro-scale particles are further modified with ATA for enhancing hemostatic properties, which verifies the valuable substrate compatibility and reveals the contact-activation hemostatic mechanism as the regulated blood (component)-material interactions. Not limited to the hemorrhage control in healthy rats/rabbits, these ATA-modified materials achieve potent hemostatic performance for intravascular hemostasis and coagulopathy condition. Our work thereby pioneers not only one potent hydrophobic coating for promising hemostatic materials, but also the appealing polyphenol/alkyl system for regulating protein/cell-material interactions.

An injectable hydrogel for hemostasis and tumor suppression in intraoperative breast cancer

In the period between surgery and systemic therapy for breast cancer, residual tumor cells may proliferate, leading to tumor recurrence. Additionally, intraoperative wound bleeding may cause surgical failure or the spread of tumor cells. This study introduces an innovative injectable hydrogel composed of oxidized hyaluronic acid (OHA) loaded 5-fluorouracil (5-FU) and N-carboxyethyl chitosan (CEC), designed for intraoperative hemostasis and tumor suppression in intraoperative breast cancer. The CEC/OHA injectable hydrogel was synthesized through a Schiff base reaction between the aldehyde group of OHA and the amino group of CEC, incorporating 5-FU during hydrogel formation. This CEC/OHA injectable hydrogel demonstrated hemostatic effects comparable to gelatin sponges in both an in vivo rat liver hemorrhage model and an in vitro rat tail amputation model. When loaded with 5-FU, the injectable hydrogel effectively inhibited the proliferation of MDA-MB-231 breast cancer cells in vitro, significantly inhibited tumor growth and recurrence in vivo, and did not induce significant damage or inflammatory response in any major organ. This CEC/OHA & 5-FU injectable hydrogel is envisioned as a complementary therapeutic regimen during the intraoperative period in breast cancer surgery to prevent hemostasis and tumor recurrence.

A self-gelling hemostatic powder boosting radiotherapy-elicited NK cell immunity to combat postoperative hepatocellular carcinoma relapse

Liver resection represents a main curative treatment for patients with early-stage hepatocellular carcinoma (HCC), but there is a rather high incidence of postoperative HCC relapse, which severely shortens long-term survival time. Currently, no standard adjuvant strategies are available for preventing HCC relapse in clinical practice. Impaired natural killer (NK) cell anti-tumor immunity has been disclosed as a crucial root of HCC relapse, indicating that reinstating NK cell anti-tumor immunity may show promise to curb HCC relapse. Coincidently, mounting evidence shows that radiotherapy (RT) can trigger NK cell anti-tumor immunity, though its mechanisms have never been completely elucidated. Herein, we uncover that RT can induce immunogenic cell death and activate cGAS-STING pathway in HCC cells to elicit NK cell anti-tumor immunity. However, RT is also revealed to enhance autophagy and CD73 expression in HCC cells, as well as neutrophil extracellular traps (NETs) formation, which largely limits RT-induced activation of NK cell anti-tumor immunity. Therefore, a cocktail of autophagy inhibitor 3-methyladenine, CD73 inhibitor ARL 67156 trisodium and NETs lyase DNase I may sensitize RT to reinvigorate NK cell anti-tumor immunity and thus prevent HCC relapse postresection. To minimize therapy-related side effects, a nanocomposite powder encapsulating such a triple-drug cocktail is developed. This powder can rapidly form adhesive hydrogel in situ after applied to surgical margin, consequently fulfilling liver-localized sustained drug delivery. Importantly, it can sensitize RT to reinstate NK cell anti-tumor immunity to combat postoperative HCC relapse in Heap1-6-HCC murine model. Besides, this powder can also generate rapid hemostasis in rat and porcine models. Altogether, this work provides an innovative strategy to thwart postoperative HCC relapse and bleeding.

A spreadable self-gelling hemostatic powder sensitizes CAR-NK cell therapy to prevent hepatocellular carcinoma recurrence postresection

Adoptive natural killer cell therapy (ANKCT) harbors great potential for combating postsurgical hepatocellular carcinoma (HCC) recurrence, but its efficacy is limited by tumor microenvironment (TME)-meditated repression on NK cell function and insufficient NK cell homing to tumor sites. Therefore, herein we develop a nanocomposite sprayable self-gelling powder enabling liver-localized codelivery of three FDA-approved drugs including calcitriol (Cal), gemcitabine (Gem), and tazemetostat (Taz) to address these challenges. This powder can be laparoscopically spread to liver wound sites, where it rapidly absorbs interfacial liquid to form a bulk adhesive pressure-resistant hydrogel in situ, implying its application potential in minimally surgery. Moreover, its application to liver resection bed significantly sensitizes allogenic NK and EpCAM chimeric antigen receptor modified-NK-92 (EpCAM-CAR-NK) cell infusion to prevent HCC recurrence in orthotopic Heap1-6 tumor-bearing and patient-derived tumor xenograft (PDX) HCC murine models. Additionally, this powder can allow for an effective hemostatic effect in rat and porcine models due to its powerful tissue adhesion-seal and erythrocyte-aggregating effects. Altogether, our newly developed hemostatic self-gelling powder can significantly sensitize ANKCT to combat HCC recurrence in a manner compatible with surgical treatment of HCC.

A gelable polymer loaded with curcumin and apatinib absorbed in gelatin sponge delays postoperative residual tumor growth

Surgical resection of the tumor remains the preferred treatment for most solid tumors at an early stage, however, residual tumor cells after surgical resection poses a considerable obstacle in cancer treatment. Here, we developed a gel carrier using a cellulose-based gel-forming polymer (CT) combined with gelatin sponge (GS) to fill the resection cavity and delay postoperative residual tumor growth. The fabricated gel exhibited a porous nature along with gradual swelling and erosion over time. Curcumin (Cur) and apatinib (Apa) were loaded into CT gel (CT-CA), and a sustained release behavior was observed at pH 7.4 and 6.4 at 37 °C. The preclinical studies indicated that the mouse weight and tissue exhibited no apparent change after administration of the GS-CT compared with the control. The in vivo fluorescence images showed that GS-CT has the capability to regulate the release of Cur and Apa, facilitating the accumulation of these two agents at the surgical tumor site. Moreover, GS-CT loaded Cur and Apa (GS-CT-CA) delayed postoperative residual tumor growth in intraperitoneal and subcutaneous postoperative mouse models. These findings demonstrated that our gel carrier system significantly prevents postoperative residual tumor growth because of enhanced drug accumulation and sustained drug release at the tumor site.

Non-antibiotic dependent photothermal antibacterial hemostatic MXene hydrogel for infectious wounds healing

On account of the existence of antibiotic resistance, the wound healing of pathogenic infection is still a challenge in modern society. A desirable wound dressing should own the abilities of adhesiveness, hemostasis and good mechanical property, meanwhile the property of eliminating bacteria without side effects is also highly needed. In this work, we established a kind of hydrogel based on carboxymethyl cellulose-graft-tyramine (CMC-Ty) and MXene (Ti3C2Tx) through employing H2O2/HRP (horseradish peroxidase) as the initiator, then the as-prepared hydrogel (named CMC-Ty/MXene) was immersed in tannic acid (TA) solution, and this TA-treated hydrogel was called CMC-Ty/MXene+TA. By employing TA as the multi-functional H-bond provider, the adhesiveness, hemostatic ability, mechanical property and bactericidal performance of the hydrogel was enhanced. And MXene in this system exerted benign photothermal antimicrobial performance, it was able to transform near-infrared (NIR) light into heat, then the bacteria would be physically damaged (thermal destruction) due to the hyperthermy, hence the antibacterial effect of which will not be restricted by antibiotic resistance. The temperature of the hydrogel in the experimental group can be increased by 25 °C after irradiation by 808 nm NIR light for 10 min, and the bactericidal efficiency against both E. coli and S. aureus reached >99 %. In vivo tests demonstrated that with the assistance of NIR irradiation, the hydrogel can distinctly accelerate the S. aureus infected wound closure. We envisage that this non-antibiotic dependent multifunctional photothermal hydrogel can provide a promise for bacteria-invaded wound healing.

Bicomponent nano- and microfiber aerogels for effective management of junctional hemorrhage

Managing junctional hemorrhage is challenging due to ineffective existing techniques, with the groin being the most common site, accounting for approximately 19.2% of potentially survivable field deaths. Here, we report a bicomponent nano- and microfiber aerogel (NMA) for injection into deep, narrow junctional wounds to effectively halt bleeding. The aerogel comprises intertwined poly(lactic acid) nanofibers and poly(ε-caprolactone) microfibers, with mechanical properties tunable through crosslinking. Optimized aerogels demonstrate improved resilience, toughness, and elasticity, enabling rapid re-expansion upon blood contact. They demonstrate superior blood absorption and clotting efficacy compared to commercial products (i.e., QuikClot® Combat Gauze and XStat®). Most importantly, in a lethal swine junctional wound model (Yorkshire swine, both male and female, n = 5), aerogel treatment achieved immediate hemostasis, a 100% survival rate, no rebleeding, hemodynamic stability, and stable coagulation, hematologic, and arterial blood gas testing.

Smart design in biopolymer-based hemostatic sponges: From hemostasis to multiple functions

Uncontrolled hemorrhage remains the leading cause of death in clinical and emergency care, posing a major threat to human life. To achieve effective bleeding control, many hemostatic materials have emerged. Among them, nature-derived biopolymers occupy an important position due to the excellent inherent biocompatibility, biodegradability and bioactivity. Additionally, sponges have been widely used in clinical and daily life because of their rapid blood absorption. Therefore, we provide the overview focusing on the latest advances and smart designs of biopolymer-based hemostatic sponge. Starting from the component, the applications of polysaccharide and polypeptide in hemostasis are systematically introduced, and the unique bioactivities such as antibacterial, antioxidant and immunomodulation are also concerned. From the perspective of sponge structure, different preparation processes can obtain unique physical properties and structures, which will affect the material properties such as hemostasis, antibacterial and tissue repair. Notably, as development frontier, the multi-functions of hemostatic materials is summarized, mainly including enhanced coagulation, antibacterial, avoiding tumor recurrence, promoting tissue repair, and hemorrhage monitoring. Finally, the challenges facing the development of biopolymer-based hemostatic sponges are emphasized, and future directions for in vivo biosafety, emerging materials, multiple application scenarios and translational research are proposed.

Cascaded immunotherapy with implantable dual-drug depots sequentially releasing STING agonists and apoptosis inducers

Non-nucleotide stimulators of interferon gene (STING) agonists hold promise as immunotherapeutic agents for postsurgical adjuvant treatment of tumors. However, their limited effect duration hampers therapeutic effectiveness, necessitating prolonged administration of multiple doses that heightens infection risk and impacts patient compliance. Here, we develop an implantable dual-drug depot in a sandwich-like configuration, with a non-nucleotide STING agonist (MSA-2) in the outer layers of 3D-printed scaffolds and an immunogenic apoptosis inducer (doxorubicin, DOX) in the inner layer of electrospun fibers. We discover that MSA-2 can elicit endoplasmic reticulum stress-mediated and general immunogenic apoptosis of cancer cells. The stimulations with tumor-associated antigens and damage-associated molecular patterns from cancer cells, along with proinflammatory factors secreted by matured dendritic cells and M1-polarized macrophages, can depolymerize intracellular microtubules guiding activated STING trafficking towards lysosomes for degradation. Collectively, the dual-drug depots can initiate a long-lasting cascaded immunotherapy and chemotherapy, suppressing postsurgical tumor recurrence and metastasis.

Evaluation of Different Commercial Sealing Hemostatic Patches for Their Selection as Reservoirs for Localized Intraperitoneal Chemotherapy

Peritoneal carcinomatosis (PC) is typically treated by cytoreductive surgery (CRS) and subsequent chemotherapy. Sealing hemostatic patches (HP) are often used during these surgeries to prevent complications such as uncontrolled bleeding. These HP are made of biomaterials like oxidized cellulose or collagen with a binding agent, and beyond their usual function, they could also be used as drug delivery systems (DDS) for localized intraperitoneal chemotherapy in the tissue attached. Our first aim was to characterize and compare three different commercial HP (TachoSil®, Hemopatch®, and VerisetTM). Hemopatch® emerged as the most suitable candidate due to its combination of properties, including slow degradation, high hydrophilicity, excellent biological fluid absorption capacity, and moderate adhesive capacity alongside hemostasis. Utilizing Hemopatch® as a scaffold, we developed a new device incorporating a hyaluronic acid hydrogel loaded with cisplatin or olaparib. This approach facilitated sustained drug release for over 6 days, maintaining the anticancer efficacy of these agents on OVCAR-3 cells. In conclusion, integrating a DDS into HP shows potential for precisely delivering chemotherapeutic agents to any residual microscopic disease in PC following CRS.

Enhanced hemostatic efficacy of cryogel with copper ion-loaded mesoporous bioactive glasses for acute and persistent bleeding

Uncontrolled acute and persistent bleeding, as well as with infection, is a great challenge because of the high mortality during treating the patients with injuries, complex surgery or bone marrow failure. Here, we develop an external form of natural components which is based on phosphorylated methacrylated gelatin (GelMA, G) cryogel (GP) loaded with tannic acid (TA)-mixed copper ion (Cu2+) mesoporous bioactive glasses (MBG), named after GP@MBG-Cu-TA cryogel, to address the goals of reduce persistent bleeding and enhance antibacterial activity. Structurally, GP@MBG-Cu-TA cryogel is based on GP, MBG loaded with TA and Cu2+ adheres to GP via hydrogen bonding. In vitro, GP@MBG-Cu-TA cryogel displays a good biocompatibility, hemostatic and antimicrobial capability. In vivo studies, GP@MBG-Cu-TA cryogel can enhance the hemostatic effect in the liver injury in SD rats for the acute bleeding, as well as in the aplastic anemia and hemophilia A mice with tail amputation for the persistent bleeding. In addition, GP@MBG-Cu-TA cryogel accelerates the skin wound repair in the mice with the bacterial contamination at the injury site. In sum, GP@MBG-Cu-TA cryogel is not only endowed with dual function of hemostatic and antimicrobial capability, but also can stop bleeding of the objects with either normal or abnormal coagulation function. Thus, GP@MBG-Cu-TA cryogel provides a promising candidate dressing for managing bleeding and bacterial complications in clinic.

Hemoadhican Fiber Composite with Carbon Dots for Treating Severe Hemorrhage and Infected Wounds

Uncontrolled bleeding and infection following trauma continue to pose significant clinical challenges. This study employs hemoadhican (HD) polysaccharide, known for its superior hemostatic properties, as the foundational material to synthesize antibacterial carbon dots (H-CDs) through a hydrothermal method at various temperatures. The H-CDs exhibiting optimal antimicrobial properties were identified via in vitro antimicrobial characterization. The selected H-CDs possess nanoscale dimensions and a positive surface charge. They contain aldehyde groups and generate reactive oxygen species, which effectively eliminate bacteria. Subsequently, H-CDs were integrated into HD fibers (CDs-HD fibers) using a wet-spinning technique. The water vapor transmission rate, blood contact angle, and in vitro antimicrobial efficacy were evaluated. In a rat model of severe femoral artery hemorrhage and a noncompressible hepatic hemorrhage model, CDs-HD fibers demonstrated superior hemostatic performance compared to the commercially available QuikClot Combat Gauze. Furthermore, in a rat model of mixed bacterial wound infection, CDs-HD fibers significantly enhanced epithelial tissue remodeling and collagen deposition. In vivo studies confirmed the excellent biocompatibility of CDs-HD fibers. These findings suggest that CDs-HD fibers hold promise as a potential dressing for managing severe bleeding and preventing wound infections.

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.

pH-responsive hydrogel with gambogic acid and calcium nanowires for promoting mitochondrial apoptosis in osteosarcoma

Calcium (Ca2+) overload therapy gained significant attention in oncology. However, its therapeutic efficacy remained limited due to insufficient Ca2+ accumulation at the tumor site and suboptimal intracellular Ca2+ influx. In this study, gambogic acid (GA), a natural phenolic compound known to promote Ca2+ influx, was encapsulated within an enzyme-triggered, pH-responsive hydrogel (GM@Lip@CHP-Gel) containing Ca2+ hydrogen phosphate nanowires (CHP) to achieve a synergistic approach for bone tumor therapy. GM@Lip@CHP-Gel selectively responded to the slightly acidic tumor microenvironment, triggering degradation of its 3D network structure and sustaining the release of GA and Ca2+ into tumor cells. GA subsequently stimulated Ca2+ influx in tumor cells, effectively disrupting Ca2+ homeostasis. CHP nanowires served as a continuous Ca2+ source, enhancing GA-mediated Ca2+ overload and promoting mitochondrial apoptosis in tumor cells. The combined strategy resulted in an in vivo tumor suppression rate of 79 % and a lung metastasis inhibition rate of 89.4 %, with a protective effect on bone tissue. The naturally derived, Ca2+-mediated treatment demonstrated physiochemical stability in physiological environments and minimized side effects on healthy organs, positioning it as a promising approach for clinical bone cancer therapy.

Flower-Like Nanosensors for Photoacoustic-Enhanced Lysosomal Escape and Cytoplasmic Marker-Activated Fluorescence: Enabling High-Contrast Identification and Photothermal Ablation of Minimal Residual Disease in Breast Cancer

The clearance of minimal residual disease (MRD) after breast cancer surgery is crucial for inhibiting metastasis and recurrence. However, the most promising biomarker-activated fluorescence imaging strategies encounter accessibility issues of the delivered sensors to cytoplasmic targets. Herein, a flower-like composite nanosensor with photoacoustic (PA) effect-enhanced lysosomal escape and cytoplasmic marker-activated fluorescence is developed to address this challenge. Specifically, the incorporation of Co2+ into the synthesis of 2D Zn2+-derived metal-organic frameworks enabled rapid dopamine polymerization and deposition. Subsequently, the composite nanoflower (FHN), characterized by an average size of ≈80 nm and petal thickness of ≈6 nm, is formed through the sealing of micropores and simultaneous cross-linking of nanosheets. The pronounced reduction in thermal conductivity of FHN, and superposition of interpetal thermal fields under a pulsed laser (PL), lead to enhanced PA effect and membrane permeability. Thereby, nanosensors efficiently escape from lysosomes resulting in synergistic fluorescence activation by dual-factors (ATP, miRNA-21) and DNA probes installed on FHN. A subsequently high tumor-to-normal tissue signal ratio (TNR) of 17.4 lead to precise guidance of NIR irradiation for efficient MRD eradication and recurrence inhibition. This study provides a new approach for high-contrast identification and precise ablation of MRD based on the synergistic response of endogenous and exogenous factors.

Preparation of accelerated-wound-healing lignin/dopamine-based nano-Fe3O4 hydrogels in sensing

Flexible conductive hydrogels hold great promise for applications in motion and medical detection. It is difficult to produce conductive hydrogel epidermal sensors in wearable hydrogels with dependable adhesion, sensing, and wound-healing properties. Nano-Fe3O4 was used as physical cross-linking points in the polyacrylamide/polyvinyl alcohol double network (PP) to increase the strain capacity of the hydrogel. The conductive lignin-dopamine (LD) was immobilized on the surface of Fe3O4 particles, and the LD-coated Fe3O4 was then incorporated into the double network hydrogel to create the PP/LD/Fe3O4 hydrogel. This work was done to look into the possibility of using Fe3O4 hydrogels as flexible strain sensors. The addition of LD/Fe3O4 caused the composite hydrogel to strain up to 124 %, with a modulus of elasticity of 21,308 Pa and electrical conductivity as high as 2.3 S•m-1 following the introduction of LD/Fe3O4. Moreover, the PP/LD/Fe3O4 hydrogel's adhesive qualities offered adequate antimicrobial properties and promoted wound healing. These results indicate that the developed electricity-responsive and tissue-adhesive hydrogel dressing offers a candidate to serve as a tissue sealant for wound healing.

Mesoporous silica thin film as effective coating for enhancing osteogenesis through selective protein adsorption and blood clotting

The role of blood clots in tissue repair has been identified for a long time; however, its participation in the integration between implants and host tissues has attracted attention only in recent years. In this work, a mesoporous silica thin film (MSTF) with either vertical or parallel orientation was deposited on titania nanotubes surface, resulting in superhydrophilic nanoporous surfaces. A proteomic analysis of blood plasma adsorption revealed that the MSTF coating could significantly increase the abundance of acidic proteins and the adsorption of coagulation factors (XII and XI), with the help of cations (Na+, Ca2+) binding. As a result, both the activation of platelets and the formation of blood clots were significantly enhanced on the MSTF surface with more condensed fibrin networks. The two classical growth factors of platelets-derived growth factors-AB and transformed growth factors-βwere enriched in blood clots from the MSTF surface, which accounted for robust osteogenesis bothin vitroandin vivo. This study demonstrates that MSTF may be a promising coating to enhance osteogenesis by modulating blood clot formation.

Postoperative tumor treatment strategies: From basic research to clinical therapy

Despite progression in advanced treatments for malignant tumors, surgery remains the primary treatment intervention, which removes a large portion of firm tumor tissues; however, the postoperative phase poses a possible risk for provincial tumor recurrence and metastasis. Consequently, the prevention of tumor recurrence and metastasis has attracted research attention. In this review, we summarized the postoperative treatment strategies for various tumors from both basic research and clinical perspectives. We delineated the underlying factors contributing to the recurrence of malignant tumors with a substantial prevalence rate, related molecular mechanisms of tumor recurrence post‐surgery, and related means of monitoring recurrence and metastasis after surgery. Furthermore, we described relevant therapeutic approaches for postoperative tumor recurrence, including chemotherapy, radiation therapy, immunotherapy, targeted therapy, and photodynamic therapy. This review focused on the emerging technologies used for postoperative tumor treatment in recent years in terms of functional classification, including the prevention of postoperative tumor recurrence, functional reconstruction, and monitoring of recurrence. Finally, we discussed the future development and deficiencies of postoperative tumor therapy. To understand postoperative treatment strategies for tumors from clinical treatment and basic research and further guide the research directions for postoperative tumors.

Tannic acid and silicate-functionalized polyvinyl alcohol-hyaluronic acid hydrogel for infected diabetic wound healing

Healing of chronic diabetic wounds is challenging due to complications of severe inflammatory microenvironment, bacterial infection and poor vascular formation. Herein, a novel injectable polyvinyl alcohol-hyaluronic acid-based composite hydrogel was developed, with tannic acid (TA) and silicate functionalization to fabricate an 'all-in-one' hydrogel PTKH. On one hand, after being locally injected into the wound site, the hydrogel underwent a gradual sol-gel transition in situ, forming an adhesive and protective dressing for the wound. Manipulations of rheological characteristics, mechanical properties and swelling ability of PTKH could be performed via regulating TA and silicate content in hydrogel. On the other hand, PTKH was capable of eliminating reactive oxygen species overexpression, combating infection and generating a cell-favored microenvironment for wound healing acceleration in vitro. Subsequent animal studies demonstrated that PTKH could greatly stimulate angiogenesis and epithelization, accompanied with inflammation and infection risk reduction. Therefore, in consideration of its impressive in vitro and in vivo outcomes, this 'all-in-one' multifunctional hydrogel may hold promise for chronic diabetic wound treatment.

Preparation and Application of Hemostatic Hydrogels

Hemorrhage remains a critical challenge in various medical settings, necessitating the development of advanced hemostatic materials. Hemostatic hydrogels have emerged as promising solutions to address uncontrolled bleeding due to their unique properties, including biocompatibility, tunable physical characteristics, and exceptional hemostatic capabilities. In this review, a comprehensive overview of the preparation and biomedical applications of hemostatic hydrogels is provided. Particularly, hemostatic hydrogels with various materials and forms are introduced. Additionally, the applications of hemostatic hydrogels in trauma management, surgical procedures, wound care, etc. are summarized. Finally, the limitations and future prospects of hemostatic hydrogels are discussed and evaluated. This review aims to highlight the biomedical applications of hydrogels in hemorrhage management and offer insights into the development of clinically relevant hemostatic materials.

Gelatin-based biomaterials and gelatin as an additive for chronic wound repair

Disturbing or disrupting the regular healing process of a skin wound may result in its progression to a chronic state. Chronic wounds often lead to increased infection because of their long healing time, malnutrition, and insufficient oxygen flow, subsequently affecting wound progression. Gelatin-the main structure of natural collagen-is widely used in biomedical fields because of its low cost, wide availability, biocompatibility, and degradability. However, gelatin may exhibit diverse tailored physical properties and poor antibacterial activity. Research on gelatin-based biomaterials has identified the challenges of improving gelatin's poor antibacterial properties and low mechanical properties. In chronic wounds, gelatin-based biomaterials can promote wound hemostasis, enhance peri-wound antibacterial and anti-inflammatory properties, and promote vascular and epithelial cell regeneration. In this article, we first introduce the natural process of wound healing. Second, we present the role of gelatin-based biomaterials and gelatin as an additive in wound healing. Finally, we present the future implications of gelatin-based biomaterials.

Development of a tannic acid- and silicate ion-functionalized PVA-starch composite hydrogel for in situ skeletal muscle repairing

The repair capacity of skeletal muscle is severely diminished in massive skeletal muscle injuries accompanied by inflammation, resulting in muscle function loss and scar tissue formation. In the current work, we developed a tannic acid (TA)- and silicate ion-functionalized tissue adhesive poly(vinyl alcohol) (PVA)-starch composite hydrogel, referred to as PSTS (PVA-starch-TA-SiO32-). It was formed based on the hydrogen bonding of TA to organic polymers, as well as silicate-TA ligand interaction. PSTS could be gelatinized in minutes at room temperature with crosslinked network formation, making it applicable for injection. Further investigations revealed that PSTS had skeletal muscle-comparable conductivity and modulus to act as a temporary platform for muscle repairing. Moreover, PSTS could release TA and silicate ions in situ to inhibit bacterial growth, induce vascularization, and reduce oxidation, paving the way to the possibility of creating a favorable microenvironment for skeletal muscle regeneration and tissue fibrosis control. The in vivo model confirmed that PSTS could enhance muscle fiber regeneration and myotube formation, as well as reduce infection and inflammation risk. These findings thereby implied the great potential of PSTS in the treatment of formidable skeletal muscle injuries.

Enteromorpha Prolifera Polysaccharide-Derived Injectable Hydrogel for Fast Intraoperative Hemostasis and Accelerated Postsurgical Wound Healing Following Tumor Resection

Intraoperative bleeding and delayed postsurgical wound healing caused by persistent inflammation can increase the risk of tumor recurrence after surgical resection. To address these issues, Enteromorpha prolifera polysaccharide (PEP) with intrinsic potentials for hemostasis and wound healing, is chemically modified into aldehyde-PEP and hydrazine-PEP. Thereby, an injectable double-network hydrogel (OPAB) is developed via forming dual dynamic bonding of acylhydrazone bonds between the decorated aldehyde and hydrazine groups and hydrogen bonds between hydroxyl groups between boric acid and PEP skeletons. The OPAB exhibits controllable shape-adaptive gelation (35.0 s), suitable mechanical properties, nonstimulating self-healing (60 s), good wet tissue adhesion (30.9 kPa), and pH-responsive biodegradability. For in vivo models, owing to these properties, OPAB can achieve rapid hemostasis within 30 s for the liver hemorrhage, and readily loading of curcumin nanoparticles to remarkably accelerate surgical wound closure by alleviating inflammation, re-epithelialization, granulation tissue formation, and collagen deposition. Overall, this multifunctional injectable hydrogel is a promising material that facilitates simultaneous intraoperative hemorrhage and postsurgical wound repair, holding significant potential in the clinical managements of bleeding and surgical wounds for tumor resection.

Supramolecular prodrug-like nanotheranostics with dynamic and activatable nature for synergistic photothermal immunotherapy of metastatic cancer

Synergistic photothermal immunotherapy has attracted widespread attention due to the mutually reinforcing therapeutic effects on primary and metastatic tumors. However, the lack of clinical approval nanomedicines for spatial, temporal, and dosage control of drug co-administration underscores the challenges facing this field. Here, a photothermal agent (Cy7-TCF) and an immune checkpoint blocker (NLG919) are conjugated via disulfide bond to construct a tumor-specific small molecule prodrug (Cy7-TCF-SS-NLG), which self-assembles into prodrug-like nano-assemblies (PNAs) that are self-delivering and self-formulating. In tumor cells, over-produced GSH cleaves disulfide bonds to release Cy7-TCF-OH, which re-assembles into nanoparticles to enhance photothermal conversion while generate reactive oxygen species (ROSs) upon laser irradiation, and then binds to endogenous albumin to activate near-infrared fluorescence, enabling multimodal imaging-guided phototherapy for primary tumor ablation and subsequent release of tumor-associated antigens (TAAs). These TAAs, in combination with the co-released NLG919, effectively activated effector T cells and suppressed Tregs, thereby boosting antitumor immunity to prevent tumor metastasis. This work provides a simple yet effective strategy that integrates the supramolecular dynamics and reversibility with stimuli-responsive covalent bonding to design a simple small molecule with synergistic multimodal imaging-guided phototherapy and immunotherapy cascades for cancer treatment with high clinical value.

3D sponge loaded with cisplatin-CS-calcium alginate MPs utilized as a void-filling prosthesis for the efficient postoperative prevention of tumor recurrence and metastasis

Intraoperative bleeding is a pivotal factor in the initiation of early recurrence and tumor metastasis following breast cancer excision. Distinct advantages are conferred upon postoperative breast cancer treatment through the utilization of locally administered implant therapies. This study devised a novel 3D sponge implant containing cisplatin-loaded chitosan-calcium alginate MPs capable of exerting combined chemotherapy and hemostasis effects. This innovative local drug-delivery implant absorbed blood and residual tumor cells post-tumor resection. Furthermore, the cisplatin-loaded chitosan-calcium alginate MPs sustainably targeted and eliminated cancer cells, thereby diminishing the risk of local recurrence and distant metastasis. This hydrogel material can also contribute to breast reconstruction, indicating the potential application of the 3D sponge in drug delivery for breast cancer treatment.

Inflammation-Driven Nanohitchhiker Enhances Postoperative Immunotherapy by Alleviating Prostaglandin E2-Mediated Immunosuppression

Inflammation contributes to the immunosuppressive microenvironment and leads to the recurrence of surgically resected tumors. The COX-2/PGE2 axis is considered a key player in shaping the immunosuppression microenvironment. However, targeted modulation of the postoperative tumor microenvironment is challenging. To specifically curb the inflammation and alleviate immunosuppression, here, we developed a PGE2 inhibitor celecoxib (CXB)-loaded bionic nanoparticle (CP@CM) coated with activated murine vascular endothelial cell (C166 cells) membrane to target postoperative melanoma and inhibit its recurrence. CP@CM adhered to inflammatory white blood cells (WBCs) through the adhesion molecules, including ICAM-1, VCAM-1, E-selectin, and P-selection, expressed on the surface of C166 cells. Leveraging the natural tropism of the WBC to the inflammatory postoperative tumor site, CP@CM efficiently targeted postoperative tumors. In melanoma postoperative recurrence models, CXB significantly reduced PGE2 secretion and the recruitment of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Treg) by inhibiting the activity of COX-2. This was followed by an increase in the infiltration of CD8+ T cells and CD4+ T cells in tumor tissues. Additionally, the immune responses were further enhanced by combining a PD-L1 monoclonal antibody. Ultimately, this immunotherapeutic strategy reversed the tumor immunosuppressive microenvironment and inhibited tumor recurrence, demonstrating a promising potential for postoperative immunotherapy for melanoma.

Exploring the vast potentials and probable limitations of novel and nanostructured implantable drug delivery systems for cancer treatment

Conventional cancer chemotherapy regimens, albeit successful to some extent, suffer from some significant drawbacks, such as high-dose requirements, limited bioavailability, low therapeutic indices, emergence of multiple drug resistance, off-target distribution, and adverse effects. The main goal of developing implantable drug delivery systems (IDDS) is to address these challenges and maintain anti-cancer drugs directly at the intended sites of therapeutic action while minimizing inevitable side effects. IDDS possess numerous advantages over conventional drug delivery, including controlled drug release patterns, one-time drug administration, as well as loading and stabilizing poorly water-soluble chemotherapy drugs. Here, we summarized conventional and novel (three-dimensional (3D) printing and microfluidic) preparation techniques of different IDDS, including nanofibers, films, hydrogels, wafers, sponges, and osmotic pumps. These systems could be designed with high biocompatibility and biodegradability features using a wide variety of natural and synthetic polymers. We also reviewed the published data on these systems in cancer therapy with a particular focus on their release behavior. Various release profiles could be attained in IDDS, which enable predictable, adjustable, and sustained drug releases. Furthermore, multi-step or stimuli-responsive drug release could be obtained in these systems. The studies mentioned in this article have proven the effectiveness of IDDS for treating different cancer types with high prevalence, including breast cancer, and aggressive cancer types, such as glioblastoma and liver cancer. Additionally, the challenges in applying IDDS for efficacious cancer therapy and their potential future developments are also discussed. Considering the high potential of IDDS for further advancements, such as programmable release and degradation features, further clinical trials are needed to ensure their efficiency. The overall goal of this review is to expand our understanding of the behavior of commonly investigated IDDS and to identify the barriers that should be addressed in the pursuit of more efficient therapies for cancer. See also the graphical abstract(Fig. 1).

NETosis: Sculpting tumor metastasis and immunotherapy

The process of neutrophil extracellular traps (NETs) formation, called NETosis, is a peculiar death modality of neutrophils, which was first observed as an immune response against bacterial infection. However, recent work has revealed the unique biology of NETosis in facilitating tumor metastatic process. Neutrophil extracellular traps released by the tumor microenvironment (TME) shield tumor cells from cytotoxic immunity, leading to impaired tumor clearance. Besides, tumor cells tapped by NETs enable to travel through vessels and subsequently seed distant organs. Targeted ablation of NETosis has been proven to be beneficial in potentiating the efficacy of cancer immunotherapy in the metastatic settings. This review outlines the impact of NETosis at almost all stages of tumor metastasis. Furthermore, understanding the multifaceted interplay between NETosis and the TME components is crucial for supporting the rational development of highly effective combination immunotherapeutic strategies with anti-NETosis for patients with metastatic disease.

Tuning Blood-Material Interactions to Generate Versatile Hemostatic Powders and Gels

Polymer-based hemostatic materials/devices have been increasingly exploited for versatile clinical scenarios, while there is an urgent need to reveal the rational design/facile approach for procoagulant surfaces through regulating blood-material interactions. In this work, degradable powders (PLPS) and thermoresponsive gels (F127-PLPS) are readily developed as promising hemostatic materials for versatile clinical applications, through tuning blood-material interactions with optimized grafting of cationic polylysine: the former is facilely prepared by conjugating polylysine onto porous starch particle, while F127-PLPS is prepared by the simple mixture of PLPS and commercial thermosensitive polymer. In vitro and in vivo results demonstrate that PLPS2 with the optimal-/medium content of polylysine grafts achieve the superior hemostatic performance. The underlying procoagulant mechanism of PLPS2 surface is revealed as the selective fibrinogen adsorption among the competitive plasma-protein-adsorption process, which is the foundation of other blood-material interactions. Moreover, in vitro results confirm the achieved procoagulant surface of F127-PLPS through optimal PLPS2 loading. Together with the tunable thermoresponsiveness, F127-PLPS exhibits outstanding hemostatic utilization in both femoral-artery-injury and renal-artery-embolization models. The work thereby pioneers an appealing approach for generating versatile polymer-based hemostatic materials/devices.

Development and evaluation of tilapia skin-derived gelatin, collagen, and acellular dermal matrix for potential use as hemostatic sponges

Hemostasis plays a critical role in the early stage of wound healing, especially in acute wounds which can significantly improve the survival of patients. Based on the excellent biocompatibility of natural biomaterials, in this study, we prepared a series of novel hemostatic sponges by using tilapia skin, a marine biological resource, and extracting tilapia skin-derived gelatin, collagen, and acellular dermal matrix through five different methods. Using in vitro sheep blood and in vivo rat liver hemorrhage models, we found that tilapia skin sponges had excellent coagulation and hemostatic abilities. Among them, the collagen sponge exhibited optimal hemostasis performance because it could accelerate clotting by binding to the specific sites of blood cells and platelets. Furthermore, the sponges' porous structure enhanced the capability to absorb blood, thus effectively promoting hemostasis. In summary, we reported an efficient and convenient method to prepare marine biological resources into sponges, which provided a novel class of alternatives for hemostasis in acute wounds with broad application prospects.

Polydopamine functionalized polyurethane shape memory sponge with controllable expansion performance triggered by near-infrared light for incompressible hemorrhage control

Uncontrolled expansion of shape memory sponges face a significant challenge in the treatment of lethal incompressible hemorrhage, which can lead to blood overflow or damage to the surrounding tissue. Herein, we developed a polydopamine functionalized polyurethane shape memory sponge (PDA-TPI-PU) with a controllable degree of expansion by near-infrared (NIR) light-triggered stimulation for the treatment of incompressible hemorrhage. The sponge has excellent liquid absorption performance and robust mechanical strength as well as good photothermal conversion ability. Under NIR light of 0.32 W/cm2, the maximum recovery rate of the fixed-shape compression sponge was 91% within 25 s in air and 80% within 25 s in blood. In the SD rat liver penetrating injury model, compared with commercial medical gelatin sponge and PVA sponge, the PDA-TPI-PU sponge could effectively control the bleeding under the NIR light irradiation and did not cause excessive compression of the wound. The sponge with these characteristics shows potential application prospects as a hemostatic material.

A Natural Self-Assembled Gel-Sponge with Hierarchical Porous Structure for Rapid Hemostasis and Antibacterial

Developing hemostatic agents with reliable biosafety and high efficiency has paramount clinical significance for saving lives. Herein, inspired from traditional Chinese medicine, a sponge (BC-S) with hierarchical porous structure is proposed for the treatment of bleeding. The BC-S is prepared by a simple self-assembly method employing Bletilla Striata polysaccharide and quaternary amine alkaloids (QA) from Bletilla Striata and Coptidis Rhizoma. The ideal cation donor encapsulated in the helical structure of BSP enlarges the inter-layer space of sponge by the action of electrostatic repulsion, forming wider channels which can accelerate the diversion speed of absorbed blood. Then, platelets and erythrocytes are trapped tightly in the reticular structure and extruded to deformation, activation. Subsequently, fibrin network forms and reinforces the internal multilayer mesh, blocks the outflow of blood. QA is released from the sponge skeleton mainly driven by a combination of surface erosion and potentially solution diffusion among pore to provide long-term antibacterial activity. Benefiting from the well-designed structure and the effective hemostatic mechanism, the BC-S displays more excellent hemostatic performance in different models in vivo and in vitro compared with typical gelatin hemostatic sponge. This work is expected to boost the development of emerging hemostatic agents.

Multimode-Responsive Luminescence of Er3+ Single-Activated CaF2 Phosphor for Advanced Information Encryption

The current optical anticounterfeit strategies that rely on multimode luminescence in response to the photon or thermal stimuli have significant importance in the field of anticounterfeiting and information encryption. However, the dependence on light and heat sources might limit their flexibility in practical applications. In this work, Er3+ single-doped CaF2 phosphors that show multistimuli-responsive luminescence have been successfully prepared. The as-obtained CaF2:Er3+ phosphor exhibits green photoluminescence (PL) and color-tunable up-conversation (UC) luminescence from red to green due to the cross-relaxation of Er3+ ions. Additionally, as-obtained CaF2:Er3+ phosphors also display green mechano-luminescence behavior, which is induced by the contact electrification between the CaF2 particles and PDMS polymers, enabling the phosphor to flexibly respond to mechanical stimuli. Moreover, feasible anticounterfeiting schemes with the capability of multistimuli-responsive and flexible decryption have been constructed, further expanding the application of optical materials in the field of advanced anticounterfeiting and information encryption.

Cryo-shocked cancer cell microgels for tumor postoperative combination immunotherapy and tissue regeneration

Prevention of recurrence/metastasis and tissue regeneration are critical for post-surgery treatment of malignant tumors. Here, to address these needs, a novel type of microgel co-loading cryo-shocked cancer cells, immunoadjuvant, and immune checkpoint inhibitor is presented by microfluidic electrospray technology and liquid nitrogen treatment. Owing to the encapsulation of cryo-shocked cancer cells and immunoadjuvant, the microgels can recruit dendritic cells and activate them in situ, and evoke a robust immune response. Moreover, with the combination of the immune checkpoint inhibitor, the antitumor immune response is further enhanced by inhibiting the interaction of PD1 and PDL1. With this, the excellent anti-recurrence and anti-metastasis efficacy of the microgels are demonstrated in an orthotopic breast cancer mouse model. Besides, because of the excellent biocompatibility and appropriate degradation performance, the microgels can provide support for normal cell adhesion and growth, which is beneficial to tissue reconstruction. These properties indicate the great value of the cryo-shocked cancer cell microgels for efficient tumor postoperative combination immunotherapy and tissue regeneration.

Progress in construction and release of natural polysaccharide-platinum nanomedicines: A review

Natural polysaccharides are natural biomaterials that have become candidate materials for nano-drug delivery systems due to their excellent biodegradability and biocompatibility. Platinum (Pt) drugs have been widely used in the clinical therapy for various solid tumors. However, their extensive systemic toxicity and the drug resistance acquired by cancer cells limit the applications of platinum drugs. Modern nanobiotechnology provides the possibility for targeted delivery of platinum drugs to the tumor site, thereby minimizing toxicity and optimizing the efficacies of the drugs. In recent years, numerous natural polysaccharide-platinum nanomedicine delivery carriers have been developed, such as nanomicelles, nanospheres, nanogels, etc. Herein, we provide an overview on the construction and drug release of natural polysaccharide-Pt nanomedicines in recent years. Current challenges and future prospectives in this field are also put forward. In general, combining with irradiation and tumor microenvironment provides a significant research direction for the construction of natural polysaccharide-platinum nanomedicines and the release of responsive drugs in the future.

An aminocaproic acid-grafted chitosan derivative with superior antibacterial and hemostatic properties for the prevention of secondary bleeding

Uncontrolled bleeding is one of the leading causes of human mortality. Existing hemostatic materials or techniques cannot meet the clinical requirements for safe and effective hemostasis. The development of novel hemostatic materials has always been of great interest. Chitosan hydrochloride (CSH), a derivative of chitin, is extensively used on wounds as an antibacterial and hemostatic agent. However, the formation of intra- or intermolecular hydrogen bonds between hydroxyl and amino groups limits its water solubility and dissolution rate and affects its effectiveness in promoting coagulation. Herein, we covalently grafted aminocaproic acid (AA) to the hydroxyl and amino groups of CSH via ester and amide bonds, respectively. The solubility of CSH in water (25 °C) was 11.39 ± 0.98 % (w/v), whereas the AA-grafted CSH (CSH-AA) reached 32.34 ± 1.23 % (w/v). Moreover, the dissolution rate of CSH-AA in water was 6.46 times higher than that of CSH. Subsequent studies proved that CSH-AA is non-toxic, biodegradable, and has superior antibacterial and hemostatic properties to CSH. Additionally, anti-plasmin activity can be exerted by the dissociated AA from the CSH-AA backbone, which can help to lessen secondary bleeding.

Biomimetic Metal-Chalcogenide Agents Enable Synergistic Cancer Therapy via Microwave Thermal-Dynamic Therapy and Immune Cell Activation

Microwave thermal dynamic therapy (MTDT), which combines thermal effects and reactive oxygen species (ROS) by microwave activation, seems to be a promising anticancer therapeutic method. A multifunctional agent for achieving synergistic localized cancer treatment is the key to exploit the strategy to inhibit tumor cell recurrence and metastasis. In the study, a ZIF-67 based theranostic agent loaded with metal-chalcogenide open framework 3 (MCOF3) and heat shock protein 70 (HSP70) as the inner component was studied, coupled with targeting cancer cell membrane (TCM) as the biomimetic outer shell. We found that metal ions in MCOF3 enabled the composite agents to show peroxide-like activity to produce •OH and destroy cancer cells. And then, the microwave (MW) thermal sensitizer of ZIF-67 was used to specifically convert the MW energy into thermal energy and selectively heat the tumor via the cell's targeting. Additionally, the effect of continuous MW thermal therapy has been shown to promote the expression of HSP70, and further activate the effector of CD4 T cell and CD8α T cell. As such, the agents effectively inhibit the tumor cell growth under MW irradiation in vitro and in vivo due to the synergistic effects of MTDT and immune cell activation. The study provides an emerging strategy to ablation cancer effectively.

Recent Advances of Platinum-Based Anticancer Complexes in Combinational Multimodal Therapy

Platinum drugs with manifest therapeutic effects are widely used, but their systemic toxicity and the drug resistance acquired by cancer cells limit their clinical applications. Thus, the exploration on appropriate methods and strategies to overcome the limitations of traditional platinum drugs becomes extremely necessary. Combination therapy of platinum drugs can inhibit tumor growth and metastasis in an additive or synergistic manner, and can potentially reduce the systemic toxicity of platinum drugs and overcome platinum-resistance. This review summarizes the various modalities and current progress in platinum-based combination therapy. The synthetic strategies and therapeutic effects of some platinum-based anticancer complexes in the combination of platinum drugs with gene editing, ROS-based therapy, thermal therapy, immunotherapy, biological modelling, photoactivation, supramolecular self-assembly and imaging modality are briefly described. Their potential challenges and prospects are also discussed. It is hoped that this review will inspire researchers to have more ideas for the future development of highly effective platinum-based anti-cancer complexes.

CD44-Targeted Photoactivatable Polymeric Nanosystem with On-Demand Drug Release as a "Photoactivatable Bomb" for Combined Photodynamic Therapy-Chemotherapy of Cancer

Nowadays, the combined use of chemotherapy and photodynamic therapy (PDT) remains the most popular strategy for cancer treatment with high theraprutic efficacy. However, targeted therapy with the on-demand release of drugs is what most clinical treatments lack, leading to heavy side effects. Herein, a new CD44-targeted and red-light-activatable nanosystem, Ru-HA@DOX nanoparticles (NPs), was developed by conjugating hydrophilic biodegradable hyaluronic acid (HA) and hydrophobic photoresponsive ruthenium (Ru) complexes, which could encapsulate the chemotherapeutic drug doxrubicin (DOX). Ru-HA@DOX NPs can selectively accumulate at the tumor through the enhanced permeability and retention (EPR) effect and CD44-mediated endocytosis, thus avoiding off-target toxicity during circulation. After 660 nm of irradiation at the tumor site, Ru-HA@DOX NPs, as a "photoactivatable bomb", was split via the photocleavable Ru-N coordination bond to fast release DOX and produce singlet oxygen (¹O₂) for PDT. In general, Ru-HA@DOX NPs retained its integrity before irradiation and possessed minimal cytotoxicity, while under red-light irradiation, Ru-HA@DOX NPs showed significant cytotoxicity due to the release of DOX and production of ¹O₂ at the tumor. Chemotherapy-PDT of Ru-HA@DOX NPs resulted in a significant inhibition of tumor growth in A549-tumor-bearing mice and reduced the cardiotoxicity of DOX. Therefore, this study offers a novel CD44-targeted drug-delivery system with on-demand drug release for synergistic chemotherapy-PDT.

Tunicate-mimetic antibacterial hydrogel based on metal ion crosslinking and chitosan functionalization for wound healing

With the increasing prevalence of drug-resistant bacterial infections and frequent occurrences of slow wound healing, the development of novel antibacterial wound dressings has become a serious challenge. Hydrogel dressings have attracted extensive attention on wound healing due to their unique three-dimensional network structures and properties. However, it is a challenge to develop natural long-acting antibacterial hydrogels with multiple functions such as excellent cell affinity, wet adhesion and mechanical properties. Inspired by the wound healing mechanism and adhesion characteristics of tunicates, a series of biomimetic antibacterial hydrogels were prepared by utilizing pyrogallol-modified chitosan (GACS) and polyvinyl alcohol (PVA) as matrix, zinc ions (Zn²⁺) as crosslinking and antibacterial agents, and ethyl N-lauroyl l-arginate hydrochloride (LAE) as the antibacterial active ingredient. The morphology, swelling, water retention, degradability, wet adhesion, biocompatibility, mechanical and rheological properties of PVA/GACS/Zn²⁺/LAE hydrogels were evaluated. And the adhesion ability conferred by the pyrogallol structures enabled the hydrogel with enhanced antibacterial effect and hemostatic ability. Moreover, the in vivo experiments on rat models with full-thickness infected wounds confirmed that PVA/GACS/Zn²⁺/LAE hydrogels could efficiently kill bacteria, significantly improve the wound microenvironment, greatly promote fibroblast proliferation and collagen deposition and ultimately accelerate wound healing. In a word, this study provided a feasible and simple way for the development of biomimetic antibacterial hydrogel dressings applied in infected wounds, which could not only seal wounds with various shapes and provide a moist and antibacterial environment for wounds, but also have certain mechanical strength, excellent wound adhesion, good biocompatibility and hemostatic performance.

Interpenetrating network expansion sponge based on chitosan and plasma for ultrafast hemostasis of arterial bleeding wounds

Preventing arterial hemorrhage by intervening within the first few minutes is critical to the patient's life. Hemostatic materials have been developed over the last decades to address this issue, nevertheless these materials alone do not contribute to improve the survival effects in many extreme conditions, which is usually caused by penetrating arterial bleeding wounds that are incompressible and deep arterial bleeding with irregularly shapes. It is well known that, after calcium ion stimulation, many intriguing changes occurred in the major components of plasma, including the activation of several coagulation factors, such as the conversion of fibrinogen to fibrin, prothrombin to thrombin, and so on. Therefore, we constructed an expansion sponge with interpenetrating network based on chitosan and plasma, while various activated coagulation factors in plasma were also loaded into the pore structure of chitosan sponges. The prepared CS-PG sponge is capable of providing a simpler and more efficient method for treating high-pressure arterial bleeding wounds, which includes three steps: Rapid sealing and adhension, Thrombin catalysis and Activated autocoagulation. As the next generation bioactive materials, compared to conventional hemostatic materials, CS-PG sponge demonstrated superior hemostatic characteristics in both rabbit femoral artery damage and rat liver injury models.

A quaternized chitosan and carboxylated cellulose nanofiber-based sponge with a microchannel structure for rapid hemostasis and wound healing

A hemostatic sponge should perform rapid hemostasis and exhibit antibacterial properties, whilst being non-toxic, breathable, and degradable. This study prepared a hemostatic sponge (CQTC) with microchannels, specifically a microchannel structure based on quaternized chitosan (QCS) and carboxylated cellulose nanofibers (CCNF) obtained by using tannic acid and Cu²⁺ complex (crosslinking agent). The sponge had low density and high porosity, while being degradable. The combination of microchannels and three-dimensional porous structure of CQTC leads to excellent liquid absorption and hemostasis ability, based on a liquid absorption rate test and in vitro hemostasis experiment. In addition, CQTC exhibited excellent antibacterial activity against both gram-negative and gram-positive bacteria, and it promoted wound healing. In conclusion, this porous and microchannel hemostatic sponge has broad application prospects as a clinical wound hemostatic material.

Bioabsorbable nano-micelle hybridized hydrogel scaffold prevents postoperative melanoma recurrence

The residual and scattered small tumor tissue or cells after surgery are the main reason for tumor recurrence. Chemotherapy has a powerful ability to eradicate tumors but always accompanied by serious side effects. In this work, tissue-affinity mercapto gelatin (GelS) and dopamine-modified hyaluronic acid (HAD) were employed to fabricate a hybridized cross-linked hydrogel scaffold (HG) by multiple chemical reactions, which could integrate the doxorubicin (DOX) loaded reduction-responsive nano-micelle (PP/DOX) into this scaffold via click reaction to obtain the bioabsorbable nano-micelle hybridized hydrogel scaffold (HGMP). With the degradation of HGMP, PP/DOX was slowly released and formed targeted PP/DOX with degraded gelatin fragments as target molecules, which increased the intracellular accumulation, and inhibited the aggregation of B16F10 cells in vitro. In mouse models, HGMP absorbed the scattered B16F10 cells and released targeted PP/DOX to suppress tumorigenesis. For another, implantation of HGMP at the surgical site reduced the recurrence rate of postoperative melanoma and inhibited the growth of recurrent tumors. Meanwhile, HGMP significantly relieved the damage of free DOX to hair follicle tissue. This bioabsorbable nano-micelle hybridized hydrogel scaffold provided a valuable strategy for adjuvant therapy after tumor surgery.

A Super Tough, Rapidly Biodegradable, Ultrafast Hemostatic Bioglue

Death happening due to massive hemorrhage has been involved in military conflicts, traffic accidents, and surgical injuries of various human disasters. Achieving rapid and effective hemostasis to save lives is crucial in urgent massive bleeding situations. Herein, a covalent cross-linked AG-PEG glue based on extracellular matrix-like amino-gelatin (AG) and PEG derivatives is developed. The AG-PEG glue gelatinizes fast and exhibits firm and indiscriminate close adhesion with various moist tissues upon being dosed. The formed glue establishes an adhesive and robust barrier to seal the arterial, hepatic, and cardiac hemorrhagic wounds, enabling it to withstand up to 380 mmHg blood pressure in comparison with normal systolic blood pressure of 60-180 mmHg. Remarkably, massive bleeding from a pig cardiac penetrating hole with 6 mm diameter is effectively stopped using the glue within 60 s. Postoperative indexes of the treated pig gradually recover and the cardiac wounds regrow significantly at 14 days. Possessing on-demand solubility, self-gelling, and rapid degradability, the AG-PEG glue may provide a fascinating stop-bleeding approach for clinical hemostasis and emergency rescue.

A natural polyphenol-functionalized chitosan/gelatin sponge for accelerating hemostasis and infected wound healing

Natural polymers have been particularly appealing for constructing hemostatic materials/devices, but it is still desirable to develop new natural polymer-based biomaterials with balanced hemostatic and wound-healing performance. In this work, a natural polyphenol-functionalized chitosan/gelatin sponge (PCGS) was prepared by the lyophilization of a chitosan/gelatin mixture solution (under a self-foaming condition to prepare the CGS) and subsequent chemical cross-linking with procyanidin (PC). Compared with the original CGS, PCGS exhibited an enhanced liquid-absorption ability, reduced surface charges, and similar/low hemolysis rate. Benefiting from such a liquid-absorption ability (∼4000% for whole blood and normal saline) and moderate surface charges, PCGS exhibited high in vitro hemostatic property and promising hemostatic performance in an in vivo femoral-artery-injury model. In addition, PCGS possessed higher antioxidant property and slightly decreased antibacterial ability than CGS, owing to the incorporation of PC. The feasibility of PCGS for treating infected wounds was further confirmed in an in vivo infected-tooth-extraction model, as the typical complication of intractable tooth-extraction bleeding. The present work demonstrated a facile approach for developing multifunctional hemostatic materials through the flexible management of natural polymers and polyphenols.

Aspirin-Loaded Cross-Linked Lipoic Acid Nanodrug Prevents Postoperative Tumor Recurrence by Residual Cancer Cell Killing and Inflammatory Microenvironment Improvement

In addition to residual cancer cells, the surgery resection-induced hyperinflammatory microenvironment is a key factor that leads to postsurgical cancer recurrence. Herein, we developed a dual-functional nanodrug Asp@cLANVs for postsurgical recurrence inhibition by loading the classical anti-inflammatory drug aspirin (Asp) into cross-linked lipoic acid nanovesicles (cLANVs). The Asp@cLANVs can not only kill residual cancer cells at the doses comparable to common cytotoxic drugs by synergistic interaction between Asp and cLANVs, but also improve the postsurgical inflammatory microenvironment by their strongly synergistic anti-inflammation activity between Asp and cLANVs. Using mice bearing partially removed NCI-H460 tumors, we found that Asp@cLANVs gave a much lower recurrence rate (33.3%) compared with the first-line cytotoxic drug cisplatin (100%), and no mice died for at least 60 days after Asp@cLANV treatment while no mouse survived beyond day 43 in the cisplatin group. This dual-functional nanodrug constructs the first example that combines residual cancer cell killing and postoperative inflammation microenvironment improvement to suppress postsurgical cancer recurrence.

Recent progress of hydrogel-based local drug delivery systems for postoperative radiotherapy

Surgical resection and postoperative radiotherapy remained the most common therapeutic modalities for malignant tumors. However, tumor recurrence after receiving such combination is difficult to be avoided because of high invasiveness and radiation resistance of cancer cells during long-term therapy. Hydrogels, as novel local drug delivery systems, presented excellent biocompatibility, high drug loading capacity and sustained drug release property. Compared with conventional drug formulations, hydrogels are able to be administered intraoperatively and directly release the entrapped therapeutic agents to the unresectable tumor sites. Therefore, hydrogel-based local drug delivery systems have their unique advantages especially in sensitizing postoperative radiotherapy. In this context, classification and biological properties of hydrogels were firstly introduced. Then, recent progress and application of hydrogels for postoperative radiotherapy were summarized. Finally, the prospects and challenges of hydrogels in postoperative radiotherapy were discussed.

Dual drug-loaded hydrogels with pH-responsive and antibacterial activity for skin wound dressing

Antibacterial and hemostatic properties are essential for wound healing dressing. In this study, a new type of hydrogel composed of gelatin methacryloyl (GelMA) and hyaluronic acid-aldehyde (HA-CHO) is fabricated by photo-crosslinking and respectively loaded with a single drug gentamicin sulfate (GS), and two drugs of GS and lysozyme (LZM). The composite hydrogel of GelMA and HA-CHO is successfully synthesized by the aldehyde and Schiff base reactions. The structures and compositions of the hydrogels with and without drug loaded are characterized by FT-IR, ¹H NMR, and XPS. Furthermore, the microstructure and swelling behaviour of hydrogels prove that the content of HA-CHO has a significant role in the formation of hydrogels with dense porous structures and super absorbent. pH 7.4 and pH 5.0 conditions are used to evaluate the drug release behaviour of the obtained hydrogels. The released amount of GS of the drug-loaded hydrogels in the acidic buffer is more than that of the physiological environment because of the cleaved Schiff base bonds and the electrostatic interaction. Especially for the dual drug-loaded hydrogel GelMA/HA-CHO/GS/LZM, the released ratio of GS is elevated from 59 % in pH 7.4 buffer to about 78 % in pH 5.0 buffer within the first 6 h, which verifies the excellent pH-stimulus responsiveness. These endow the GS-LZM dual drug-loaded hydrogels with superior antibacterial efficiencies to that of the single GS drug-loaded hydrogels, no drug-loaded hydrogels, and SEBS control, especially in inhibiting S. aureus in a lower concentration of 10⁶ CFU mL^-1, which can be attributed to the synergistic effect of LZM and GS. For S. aureus at 10⁶ CFU mL^-1, the bacterial survival of GelMA/HA-CHO/GS/LZM is 1.1 %, which shows outstanding antibacterial effect. Hence, the drug-loaded hydrogels, especially the dual drug-loaded hydrogels with pH-responsive, antibacterial, and hemostatic properties have great potential as wound healing materials.