Inflammation-Responsive Drug-Loaded Hydrogels with Sequential Hemostasis, Antibacterial, and Anti-Inflammatory Behavior for Chronically Infected Diabetic Wound Treatment

Transformative lactera-polypyrrole@carrageenan microparticles leveraging NIR for skin regeneration and stress relief

Effective wound healing remains a significant challenge in regenerative medicine, particularly in minimizing inflammation and promoting scarless recovery. This study introduces a bioengineered LAC-PPy@Car MF composite, designed to leverage near-infrared (NIR)-induced photothermal therapy alongside biotherapeutics to facilitate tissue regeneration. The composite integrates the photothermal properties of polypyrrole (PPy) with the anti-inflammatory and regenerative potential of Lactera (LAC) and Carrageenan (Car). Upon NIR activation, the composite generates localized mild-hyperthermia, reducing oxidative stress, enhancing Aryl Hydrocarbon Receptor (AhR) activity, and upregulating heat shock proteins (HSP). These effects synergistically create a bioactive environment conducive to cellular proliferation and tissue repair. Biochemical evaluations demonstrate that LAC-PPy@Car MF effectively reduces oxidative stress, stimulates fibroblast migration, and promotes the proliferation of skin cells. Immunofluorescence staining reveals significant activation of AhR and HSP in treated tissues, correlating with cellular proliferation and improved skin architecture. The NIR-triggered photothermal effect contributes to the therapeutic potential of the composite, ensuring precise and minimally invasive treatment for burn injuries. These findings position phototherapeutic LAC-PPy@Car MF as a promising candidate for advanced wound healing applications. Its dual functionality, combining photothermal therapy with bioactive healing properties, offers a transformative approach to regenerative medicine, paving the way for improved clinical outcomes in wound care.

A multifunctional mitochondria-protective gene delivery platform promote intervertebral disc regeneration

Intervertebral disc degeneration (IDD) is a deleterious condition driven by localized inflammation and the associated disruption of the normal homeostatic balance between anabolism and catabolism, contributing to progressive functional abnormalities within the nucleus pulposus (NP). Despite our prior evidence demonstrating that a miR-21 inhibitor can have regenerative effects that counteract the progression of IDD, its application for IDD treatment remains limited by the inadequacy of current local delivery systems. Here, an injectable tannic acid (TA)-loaded hydrogel gene delivery system was developed and used for the encapsulation of a multifunctional mitochondria-protecting gene nanocarrier (PHs). This engineered platform was designed for the sustained on-demand delivery of both miR-21 inhibitor and ss-31 (mitochondrial-targeted peptide) constructs to the NP. This prepared hydrogel could be implanted into the intervertebral disc using a minimally invasive approach whereupon it was able to rapidly release TA. Sustained PHs release was then achieved as appropriate through a mechanism mediated by the activity of MMP-2. Following the targeted uptake of PHs by degenerated NP cells, the subsequent release of encapsulated miR-21 inhibitor suppressed apoptotic cell death and modulated the metabolism of the extracellular matrix (ECM) by targeting the Spry1 gene. At the same time, ss-31 was able to target damaged mitochondria and alleviate inflammatory activity via the suppression of mitochondrial ROS-NLRP3-IL-1β/Caspase1 pathway activity. Synergistic ECM regeneration and anti-inflammatory effects were sufficient to provide therapeutic benefits in an in vivo model of IDD. Together, these results thus highlight this hydrogel-based gene delivery platform as a promising novel approach to the treatment of IDD.

Dissolving Microneedles Embedded with Photosensitizers for Targeted Eradication of Gram-Positive Bacteria in Multidrug-Resistant Biofilms in Diabetic Wound Infections

Chronic nonhealing wounds, common in diabetic patients, represent a major clinical challenge, causing significant morbidity and healthcare costs. Persistent bacterial biofilms are a critical obstacle to wound healing, necessitating their effective elimination to promote rapid recovery. In photodynamic antimicrobial therapy (PDAT), enhancing the interaction between the photosensitizer and bacterial biofilms is key to achieving efficient antimicrobial and antibiofilm effects. Here, a novel dissolvable microneedle patch containing a benzoxaborole (BOB)-functionalized photosensitizer is designed, TPI-BOB, for bacteria-specific targeting and localized PDAT of multidrug-resistant biofilm infections in diabetic wounds. TPI-BOB integrates a BOB moiety for selective bacterial binding and a pyridine-based cationic group to enhance electrostatic interactions, showing superior antimicrobial activity in Gram-positive bacteria, particularly MRSA. To further optimize therapeutic delivery and combat biofilm-associated infections, TPI-BOB is incorporated into dissolvable microneedles, which rapidly disintegrate upon application to wound sites. This microneedle system facilitates localized, efficient delivery of TPI-BOB to bacterial biofilms, where it triggers photodynamic action under white-light irradiation. This treatment eradicates the biofilm, initiating tissue repair that reduces inflammation, promotes collagen deposition, and stimulates angiogenesis, accelerating healing. This work presents a novel strategy combining PDAT with microneedle-mediated drug delivery, offering a promising approach for treating diabetic wounds and other biofilm-related infections.

Metal-polyphenol nanoparticles-loaded carboxymethyl cellulose-based microneedle for promoting the healing of diabetic wounds

Inflammation and infection are significant barriers to the healing of diabetic wounds. Infectious wounds are often associated with the formation of bacterial biofilms, which impede the penetration of conventional drugs. In this study, we developed a novel metal-polyphenol composite nanoparticle (EGCG-Cu2+ NPs) by combining epigallocatechin gallate (EGCG) with Cu2+ and incorporated these nanoparticles into microneedles (MNs) made from polyvinylpyrrolidone (PVP) and sodium carboxymethyl cellulose (CMCNa). The resulting EGCG-Cu2+ MNs exhibited remarkable anti-inflammatory and antibacterial properties, achieving over 95 % inhibition against S. aureus and P. aeruginosa. Moreover, they effectively scavenged reactive oxygen species (ROS), inhibited the M1 polarization of macrophages, and promoted their M2 polarization. In diabetic wound infection models, the EGCG-Cu2+ MNs enhanced collagen deposition and angiogenesis, resulting in over 92 % wound closure within 14 days. This study provides a significant theoretical basis for innovative treatment strategies for infectious diabetic wounds, highlighting its promising clinical application potential.

A methacrylated pullulan hydrogel incorporating phycocyanin-functionalized copper sulfide nanoparticles for photothermal antibacterial therapy and improved wound healing

Bacteria-associated wound infections impose a significant burden on patients and healthcare systems. Consequently, there is an urgent need to develop a novel multifunctional antibiotic-free dressing that can effectively prevent wound infections and promote healing. In this study, a multifunctional hydrogel (PulMA/CuS@PC) was synthesized by encapsulating phycocyanin-Functionalized copper sulfide nanoparticles (CuS@PC) in photo-crosslinkable methacrylated pullulan (PluMA), exhibiting photothermal antibacterial properties and enhanced wound healing capabilities. The PulMA/CuS@PC hydrogel exhibits excellent mechanical properties, favorable swelling ability, good biocompatibility, and effective photothermal antibacterial activity. The incorporation of CuS@PC NPs significantly enhances the hydrogel's photothermal antibacterial efficacy against Escherichia coli and Staphylococcus aureus. Furthermore, the PulMA/CuS@PC hydrogel demonstrated substantial wound healing capability in a mouse model of full-thickness skin infection. This was evidenced by a marked reduction in inflammatory response as well as notable improvements in both wound healing and collagen deposition. This study underscores the potential clinical application of the developed multifunctional PulMA/CuS@PC hydrogel as an innovative wound dressing designed to prevent infection while facilitating skin regeneration.

Construction of pH-Sensitive Multifunctional Hydrogel with Synergistic Anti-Inflammatory Effect for Treatment of Diabetic Wounds

Background/Objectives: A sustainable inflammatory response is a significant obstacle for diabetic wound care. In this study, the pH-sensitive multifunctional hydrogel ODex/BSA-Zn was fabricated via a Schiff base and coordination force for the first time. Methods: The hydrogel consisted of oxidized dextran (ODex), bovine serum albumin (BSA), and zinc ions (Zn2+) in the absence of an additional crosslinking agent. Results: The hydrogel showed excellent mechanical stability, fast self-healing ability, and significant anti-inflammatory effects, as demonstrated by the formation of dynamic covalent bonds between the aldehyde group (-CHO) of ODex and the amino group (-NH2) of BSA via the Schiff base reaction, as well as the metal-ion coordination reaction of Zn2+ with the imidazole ring of BSA. In a diabetic mouse full-thickness cutaneous defect wound model, the ODex/BSA-Zn hydrogel could effectively inhibit the inflammatory response and increase collagen deposition, thereby accelerating the transition of macrophage M1 to M2 and promoting wound closure. This study offers a promising therapeutic approach for managing long-term diabetic ulcers.

Review: Advances in multifunctional hydrogels based on carbohydrate polymer and protein in the treatment of diabetic wounds

Diabetic wounds healing is often severely slowed by hyperglycemia, elevated oxidative stress, bacterial infections, and persistent inflammation. This review focuses on the development of hydrogels derived from carbohydrate polymer and protein to facilitate diabetic wound healing. We discuss the primary sources of cellulose, chitosan, hyaluronic acid, sodium alginate, collagen, and gelatin along with their advantages in the preparation of hydrogels. Based on the microenvironment of diabetic wounds, i.e., hyperglycemia, increased oxidative stress, and persistent inflammation, the application of multifunctional hydrogels in promoting diabetic wounds, including stimulus responsiveness, injection self-healing, antibacterial, antioxidant, anti-inflammatory, and synergistic effects, is discussed. We address the main challenges and future perspectives of multifunctional hydrogels based on carbohydrate polymer and protein in the treatment of diabetic wounds.

Stimuli-Responsive Nanomedicines for the Treatment of Non-cancer Related Inflammatory Diseases

Nanomedicines offer a means to overcome the limitations associated with traditional drug dosage formulations by affording drug protection, enhanced drug bioavailability, and targeted drug delivery to affected sites. Inflamed tissues possess unique microenvironmental characteristics (including excessive reactive oxygen species, low pH levels, and hypoxia) that stimuli-responsive nanoparticles can employ as triggers to support on-demand delivery, enhanced accumulation, controlled release, and activation of anti-inflammatory drugs. Stimuli-responsive nanomedicines respond to physicochemical and pathological factors associated with diseased tissues to improve the specificity of drug delivery, overcome multidrug resistance, ensure accurate diagnosis and precision therapy, and control drug release to improve efficacy and safety. Current stimuli-responsive nanoparticles react to intracellular/microenvironmental stimuli such as pH, redox, hypoxia, or specific enzymes and exogenous stimuli such as temperature, magnetic fields, light, and ultrasound via bioresponsive moieties. This review summarizes the general strategies employed to produce stimuli-responsive nanoparticles tailored for inflammatory diseases and all recent advances, reports their applications in drug delivery, and illustrates the progress made toward clinical translation.

Engineered Exosomes Loaded in Intrinsic Immunomodulatory Hydrogels with Promoting Angiogenesis for Programmed Therapy of Diabetic Wounds

Inducing rapid angiogenesis by delivering specific biological cues is critical for diabetic wound healing. Nevertheless, the angiogenesis is hindered by the inflammatory microenvironment, and the immune cells fail to orchestrate immune responses to wound healing. Herein, vascular endothelial growth factor (VEGF) plasmids-loaded macrophage exosomes (Exos) were fabricated and enfolded in injectable self-healing hydrogels for programmed therapy of diabetic wounds through sequentially intrinsically modulating the inflammatory microenvironment and promoting angiogenesis. The hydrogels, formed via dynamical Schiff base reactions using modified polysaccharides, intrinsically regulate the inflammatory microenvironment via broad-spectrum antioxidant activity and macrophage phenotype regulation, restoring tissue redox and immune homeostasis. Furthermore, the hydrogels can stabilize and release the engineered exosomes. By integration of generation and release of VEGF by plasmids-loaded macrophage Exos, VEGF secretion by M2 macrophages, and enhanced binding of VEGF to VEGF receptor 2 by high affinity of sulfated chitosan, the intrinsic immunomodulatory hydrogels effectively promote the angiogenesis and accelerate the diabetic wound healing process.

Functional hydrogels for accelerated wound healing: advances in conductive hydrogels and self-powered electrical stimulation

Compared to traditional dressings, hydrogel dressings not only protect the wound surface and prevent bacterial infection but also possess excellent moisturizing properties, which can provide an optimal moist environment for wound healing, and exhibit good biocompatibility, making them considered the best wound treatment materials. This review focuses on the research status and application progress of various functional hydrogel dressings, such as hemostatic, antimicrobial, anti-inflammatory, antioxidant, and conductive hydrogels. It proposes the combination of conductive hydrogels with flexible solar cells to form self-powered devices. Compared to traditional externally powered devices, this approach can reduce carbon footprints by utilizing clean energy, aligning with carbon neutrality policy requirements. Additionally, it eliminates the need for frequent battery replacement or power connections, effectively saving labor and operational costs. Self-powered devices can convert solar energy into electrical energy, which is conducted to the wound site through hydrogels, generating continuous electrical stimulation (ES). This electrical stimulation guides the directional migration of keratinocytes and fibroblasts toward the center of the wound; activates the MAPK/ERK signaling pathway to accelerate the cell cycle process, and upregulates the expression of vascular endothelial growth factor, thereby inducing endothelial cell proliferation and lumen formation. These multiple mechanisms work synergistically to promote wound healing. Finally, the review provides an outlook on the emergence and applications of multifunctional hydrogels and stimuli-responsive hydrogels, highlighting common challenges in the future development of hydrogels, such as weak mechanical strength and poor long-term stability, as well as feasible solutions to these issues.

Biobased Physicochemical Reversible Dual-Cross-Linked Hydrogel: Self-Healing, Antibacterial, Antioxidant, and Hemostatic Properties for Diabetic Wound Healing

Skin wound healing remains challenging due to a lack of ideal wound dressings suitable for acute and chronic wounds. This study introduced a biocompatible hydrogel wound dressing, synthesized through a green chemistry approach, specifically designed to meet the dual needs of acute and chronic wound care. The innovative strategy utilized sustainable biomaterials, soy protein, and vanillin, to construct a physical-reversible chemical dual-cross-linked hydrogel exhibiting high mechanical strength, excellent adhesion, and toughness. Schiff base reversible covalent bonds enabled rapid self-healing within 10 s, significantly improving durability. In a rat liver hemorrhage model, the hydrogel rapidly sealed wounds, achieving effective hemostasis, indicating great potential for acute wound care. Furthermore, vanillin imparted the hydrogel with antimicrobial and antioxidant properties, effectively accelerating diabetic chronic wound healing. This safe and efficient advanced biobased hydrogel offers a novel perspective for wound treatment and holds significant promise for clinical applications.

An injectable responsive exosome-releasing hydrogel based on sodium alginate restores motor and bladder function by alleviating the injury microenvironment and facilitating distal nerve repair

In the early stage of spinal cord injury (SCI), excessive reactive oxygen species (ROS) accumulate at the injury site to establish a microenvironment favoring complex secondary injuries, including cavity formation, and impacting the distal lumbosacral spinal cord. Currently, no definitive clinical treatment is available for SCI. Here, we created an responsive and injectable hydrogel composite (GEL-EXO) by modifying and cross-linking biological macromolecules sodium alginate (SA) and gelatin in the form of embedded exosomes. This GEL-EXO composite integrated the bioactivity of exosomes with the gap-filling function of hydrogels. Our experiments demonstrated that the composite could simultaneously repair spinal cord tissues at the injury site and the distal lumbosacral region, thereby restoring motor function and reinitiating bladder function. This therapeutic strategy may promise a brand-new holistic intervention for SCI.

Advanced therapeutic strategy: A single-dose injection of a dual-loaded 6-mercaptopurine gelatin-based hydrogel for effective inhibition of tumor growth

The suboptimal aqueous solubility and pronounced systemic toxicity pose significant constraints on the clinical utility of 6-mercaptopurine (6-MP). This study presents an innovative approach using injectable sustained-release hydrogels for localized drug delivery. A gelatin-based anticancer hydrogel (Gel-MP@Gel@6-MP) was developed to deliver 6-MP through both physical encapsulation and chemical coupling via CS bonds, providing a multistage sustained release platform. In vitro experiments demonstrated that physically encapsuled drug achieved rapid release within 4 h, comparable to intravenous administration kinetics. Furthermore, in the presence of glutathione (GSH), nucleophilic attack triggered slow release of S-(6-purinyl) glutathione (PG) and a minor amount of 6-MP, with sustained release observed for up to 96 h. This suggests that, in contrast to conventional delivery methods, the proposed system not only facilitates an initial high-concentration drug release lasting hours, but also enables the sustained release of drug fragments over an extended period of several days, owing to the gradual cleavage of chemical bonds following one single injection. Ultimately, in vivo antitumor studies revealed superior tumor inhibition with Gel-MP@Gel@6-MP compared to free 6-MP. This dual drug loading strategy significantly prolongs drug action duration and obviates the necessity for repeated drug administrations, thereby revealing the diverse modes of drug administration.

Silver Nanoparticles Prepared Using Magnolia officinalis Are an Effective Antimicrobial Agent on Candida albicans, Escherichia coli, and Staphylococcus aureus

Silver nanoparticles (AgNPs) prepared by plants are simple, eco-friendly, and economical. In this study, Magnolia officinalis (MO) extract was applied to synthesize MO@AgNPs. Ultraviolet-visible (UV-vis) spectrum analysis indicated a peak at 440 nm. Most of the particles were spherical with sizes from 1 to approximately 60 nm based on transmission electron microscopy (TEM). X-ray diffraction (XRD) patterns showed a face-centered cubic crystal structure. The zeta value of MO@AgNPs was - 36.5 ± 0.6 mV, which was stable at 25 °C and 4 °C. Growth kinetic studies and the Kirby-Bauer diffusion method showed significant inhibitory activity on Candida albicans (ATCC 10231), Escherichia coli (ATCC BAA-2340), and Staphylococcus aureus (ATCC 25923); the minimum inhibitory concentrations (MIC) were 3, 9, and 9 μg/mL, and corresponding minimum bactericidal concentrations (MBC) were 5, 11, and 9 μg/mL, respectively. MO@AgNPs exhibited better antifungal activity compared to AgNPs prepared using sodium citrate. Further research revealed that MO@AgNPs increased the permeability of bacterial cell membranes. Moreover, the effect of MO@AgNPs on Candida albicans was significantly enhanced by blocking autophagy. The reactive oxygen species (ROS) induced by MO@AgNPs in Candida albicans was limited and may be related to its good antioxidant activity. Finally, MO@AgNPs have no significant cytotoxicity to the human liver LO2 cell line under 20 μg/mL.

Skin-Inspired and Self-Regulated Hydrophobic Hydrogel for Diabetic Wound Therapy

Diabetic wounds are refractory and recurrent diseases that necessitate the development of multifunctional dressings. Inspired by the structure and function of the skin, we herein delicately design a novel swollen hydrophobic hydrogel (QL@MAB) composed of hydrophobic methyl acrylate (MA) and (3-acrylamidophenyl)boronic acid (AAPBA) network and co-loaded with antioxidant quercetin (Q) and antibiotic levofloxacin (L) for efficient diabetic wound therapy. The hydrophobic MA segments undergo phase separation to form a dense "epidermis", ensuring prolonged drug diffusion, long-term water retention, and high water content. Meanwhile, the AAPBA segments generate glucose-labile "sweat pores" via borate ester bonds with the polyphenol drug Q. Upon encountering the hyperglycemic wound microenvironment, the "sweat pores" are dilated due to the cleavage of the borate ester bonds and exposure of the diffusion channel, facilitating drug release for accelerated wound healing. In the infected diabetic rats, QL@MAB achieves rapid wound debridement and re-epithelization while promoting angiogenesis, hair follicle regeneration, and extracellular matrix remodeling. Taken together, this study not only represents a multipronged dressing for effective interventions of diabetic wounds but also contributes to the rational design of smart hydrogels tailored for biomedical applications.

A Narrative Review of Bioactive Hydrogel Microspheres: Ingredients, Modifications, Fabrications, Biological Functions, and Applications

Hydrogel microspheres are important in regenerative medicine and tissue engineering, acting as cargos of cells, drugs, growth factors, bio-inks for 3D printing, and medical devices. The antimicrobial and anti-inflammatory characteristics of hydrogel microspheres are good for treating injured tissues. However, the biological properties of hydrogel microspheres should be modified for optimal treatment of various body parts with different physiological and biochemical environments. In addition, specific preparation methods are required to produce customized hydrogel microspheres with different shapes and sizes for various clinical applications. Herein, the advances in hydrogel microspheres for biomedical applications are reviewed. Synthesis methods for hydrogel precursor solutions, manufacturing methods, and strategies for enhancing the biological functions of these hydrogel microspheres are described. The involvement of bioactive hydrogel microspheres in tissue repair is also discussed. This review anticipates fostering more insights into the design, production, and application of hydrogel microspheres in biomedicine.

Recent advances in the development of hydrogel dressings for the treatment of pressure ulcers/injuries

Pressure ulcers, also known as pressure injuries, are common conditions that result from chronic bedrest. These ulcers significantly affect quality of life and substantially burden individuals and society with health costs. The prevention and treatment of pressure ulcers is a primary concern for health care professionals. Dressings play a crucial role in the treatment of pressure ulcers. Hydrogels are innovative safe materials that show great promise for clinical applications. Recent research has demonstrated the potential of hydrogel dressings to promote the healing of pressure ulcers and chronic wounds. This review aims to summarize the mechanisms and effects of hydrogel dressings and to discuss considerations for their use in patients with pressure injuries under different circumstances. Hydrogel dressings, especially loaded with unique cargo, may represent promising new options for the treatment of pressure ulcers. However, additional clinical studies are urgently needed to validate the efficacy and accessibility of hydrogels in clinical practice.

Catalase-like Nanozyme-Hybrid Hydrogels Utilizing Endogenous ROS as an Oxygen Source To Synergically Regulate Oxidative Stress and Hypoxia for Enhanced Diabetic Wound Healing

High levels of reactive oxygen species (ROS) and hypoxia in diabetic wounds significantly hinder the healing process. In this work, a kind of catalase-like nanozyme-hybrid hydrogel was developed to explore the potential of harnessing endogenous excessive ROS as an oxygen source to synergistically regulate oxidative stress and hypoxia, thereby enhancing diabetic wound healing. The hydrogels exhibited rapid degradation and controlled release of ferrihydrite nanozymes in response to oxidative stress, which continuously catalyzed the decomposition of H2O2 to generate oxygen, effectively scavenging ROS and reducing the risk of local oxygen toxicity. The hydrogels relieved intracellular oxidative stress and the hypoxic microenvironment simultaneously in vitro. The hydrogel dressings effectively inhibited oxidative damage at wound sites, promoted epidermis formation and collagen deposition, and significantly accelerated wound healing in db/db mice. Therefore, the catalase-like nanozyme-hybrid hydrogels represent a promising strategy for diabetic wound dressings, addressing both oxidative stress and hypoxia to improve healing outcomes.

Instantaneous Self-Healing Chitosan Hydrogels with Enhanced Drug Leakage Resistance for Infected Stretchable Wounds Healing

Self-healing hydrogels are intelligent wound dressings to repair structural damage caused by limb movement, demonstrating advantages in stretchable wound management. Chitosan is widely used in the preparation of hydrogels due to the biocompatibility and biodegradability. However, the self-healing efficiency and mechanical strength of chitosan hydrogels are not ideal. To address the issues, three self-healing hydrogels: the single schiff base network hydrogels (OH), the double schiff-base bond network hydrogel (OHD), and borate ester bond/schiff base bond (OHPB) are designed. The self-healing time of OHPB is only 0.7 s measured by real-time electrochemical test, while the self-healing time of OH and OHD is 3.5 h and 1.5 h. Furthermore, OHPB hydrogel exhibits the desirable mechanical strength and tissue adhesion. Following the destruction-repair process, CIP and exosome loaded OHPB (ec⊂OHPB) hydrogel displays approximate 100% drug leakage resistance to achieve long-term antibacterial, cells migration promotion and M2 polarization. ec⊂OHPB hydrogel significantly accelerates infected stretchable wounds healing by relieving inflammation, facilitating angiogenesis and collagen deposition, promoting epidermal remodeling. Consequently, OHPB hydrogel with instantaneous self-healing property and enhanced drug leakage resistance performance makes it possible to broaden the application prospects of chitosan hydrogel dressings.

Boosting mRNA-Engineered Monocytes via Prodrug-Like Microspheres for Bone Microenvironment Multi-Phase Remodeling

Monocytes, as progenitors of macrophages and osteoclasts, play critical roles in various stages of bone repair, necessitating phase-specific regulatory mechanisms. Here, icariin (ICA) prodrug-like microspheres (ICA@GM) are developed, as lipid nanoparticle (LNP) transfection boosters, to construct mRNA-engineered monocytes for remodeling the bone microenvironment across multiple stages, including the acute inflammatory and repair phases. Initially, ICA@GM is prepared from ICA-conjugated gelatin methacryloyl via a microfluidics system. Then, monocyte-targeting IL-4 mRNA-LNPs are then prepared and integrated into injectable microspheres (mRNA-ICA@GM) via electrostatic and hydrogen bond interactions. After bone-defect injection, LNPs are controlled released from mRNA-ICA@GM within 3 days, rapidly transfecting monocytes for monocyte IL-4 mRNA-engineering, which effectively suppressed acute inflammatory responses via polarization programming and paracrine signaling. Afterwards, ICA is sustainably released as well via cleavable boronate esters across multiple stages, cooperatively boosting the mRNA-engineered monocytes to inhibit coenocytic fusion and osteoclastic function. Both in vitro and in vivo data indicated that mRNA-ICA@GM can not only reverse the inflammatory environment but also suppress monocyte-derived osteoclast formation to accelerate bone repair. In summary, mRNA-engineered monocytes and ICA prodrug-like microspheres are combined to achieve long-lasting multi-stage bone microenvironment regulation, offering a promising repair strategy.

Harnessing Nature's Power: Plant and Polymeric-Based Antibacterials as Potential Therapeutics for Infectious Skin Wound Healing

This comprehensive review explores the potential of plant- and biopolymeric-based antibacterials as innovative therapeutic agents for infectious skin wound healing. By researching the antibacterial properties of various plants, the review highlights their application in skin tissue engineering. Beyond reviewing antibacterial plant extracts, the article delves into the limitations these natural compounds face, such as hydrophilicity, drug release rates, cell attachment, and scaffold stability when integrated into tissue engineering constructs. The review also emphasizes the role of biopolymeric materials, hydrogel optimization, and crosslinkers to improve scaffold performance. This review provides a roadmap for future research by addressing critical factors in scaffold construction. In the end, it aims to guide the development of more effective wound dressings and tissue scaffolds, combining the natural power of plants with advanced biopolymeric materials for enhanced wound healing therapies.

Construction of GOx-loaded metal organic frameworks antibacterial composite hydrogels for skin wound healing

Bacterial infections and inflammation severely impede wound healing. Here, we developed a zwitterionic hydrogel incorporating MOF/GOx for pH-responsive, controlled drug release. The multifunctional hydrogel embedded with MOF/GOx was successfully prepared through the Schiff base reaction between the copolymer poly[(2-methacryloyloxyethyl phosphorylcholine)-co-(4-formylphenyl methacrylate)] (PMF) and the branched polyethylenimine (PEI) modified by the zwitterionic monomer ((4-hydroxyphenyl)sulfonyl)(4-(trimethylammonio)butanoyl)amide (AB), which possessed excellent injectable and self-healing ability, a highly sensitive and reversible responsiveness to pH changes, and good biocompatibility. Moreover, the MOF/GOx-PP composite hydrogel under exposure to a slightly acidic environment would rupture, and the slowly released MOF/GOx triggered a cascade-catalyzed reaction that could inhibit and kill Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and, simultaneously, mouse experiments indicated that the wound healing rate showed 93 % wound closure in 7 days compared to 67 % with controls. The multifunctional antibacterial hydrogel has immense potential as a dressing in the treatment of infected wounds.

Low-temperature cold plasma promotes wound healing by inhibiting skin inflammation and improving skin microbiome

Wound healing includes four consecutive and overlapping stages of hemostasis, inflammation, proliferation, and remodeling. Factors such as aging, infection, and chronic diseases can lead to chronic wounds and delayed healing. Low-temperature cold plasma (LTCP) is an emerging physical therapy for wound healing, characterized by its safety, environmental friendliness, and ease of operation. This study utilized a self-developed LTCP device to investigate its biological effects and mechanisms on wound healing in adult and elderly mice. Histopathological studies found that LTCP significantly accelerated the healing rate of skin wounds in mice, with particularly pronounced effects in elderly mice. LTCP can markedly inhibit the expression of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) and senescence-associated secretory phenotype factors (MMP-3, MMP-9), while significantly increasing the expression of tissue repair-related factors, such as VEGF, bFGF, TGF-β, COL-I, and α-SMA. It also regulated the expression of genes related to cell proliferation and migration (Aqp5, Spint1), inflammation response (Nlrp3, Icam1), and angiogenesis (Ptx3, Thbs1), promoting cell proliferation and inhibit apoptosis. Furthermore, LTCP treatment reduced the relative abundance of harmful bacteria such as Delftia, Stenotrophomonas, Enterococcus, and Enterobacter in skin wounds, while increasing the relative abundance of beneficial bacteria such as Muribaculaceae, Acinetobacter, Lachnospiraceae NK4A136_group, and un_f__Lachnospiraceae, thereby improving the microbial community structure of skin wounds. These research findings are of significant implications for understanding the mechanism of skin wound healing, as well as for the treatment and clinical applications of skin wounds, especially aging skin.

12-Hydroxy-Lauric Acid Tethered Self-Assembled Heterochiral Diphenylalanine-Based Mechanoresponsive and Proteolytically Stable Hydrogel: A Dual Player for Handling Cancer and Bacterial Challenges

Deciphering the most promising strategy for the evolution of cancer patient management remains a multifaceted, challenging affair to date. Additionally, such approaches often lead to microbial infections as side effects, probably due to the compromised immunity of the patients undergoing such treatment. Distinctly, this work delineates a rational combinatorial strategy harnessing stereogenic harmony in the diphenylalanine fragment, tethering it to an amphiphile 12-hydroxy-lauric acid at the N-terminus (compounds I-III) such that a potential therapeutic could be extracted out from the series. Aligned to the goal, the cytotoxic properties and cell viability of the compounds were investigated using two distinct cell lines: MCF-7 (human breast cancer cell) and HEK 293 (human embryonic kidney). Our rigorous investigations revealed that compounds I-III exhibited substantial cytotoxic impact on the MCF7 cell line. But from a pool of three constructs, compound III (12-hydroxy-lauric acid -d-Phe-l-Phe-OH) showed better selectivity toward cancerous MCF7 over normal HEK 293 in comparison to others, backed by computational calculations. Henceforth, it was fished out from the series and used for its elaborate anticancer activities using cell reactive oxygen species generation, DNA fragmentation, and caspase-dependent gene expression employing extrinsic and intrinsic apoptotic factors as well as inflammatory biomarkers, namely, TNF-α and IL1-β. We anticipated that compound III, possessing mechanoresponsiveness and a nanofibrillar network, could be administered in patients with injections because of its shear-thinning properties. Moreover, the optimum partition coefficient of compound III might have allowed the scaffold to penetrate the cellular membranes and form a dilactate complex (compound VI) when exposed to the accumulated lactates/lactic acids, a common phenomenon observed within the hypoxic cancerous tumor cores, in accordance with the Warburg mechanism, thereby evading the cytotoxicity within normal cells. Besides, the supramolecular β-sheets of compound III manifest substantial antimicrobial efficacy against the common pathogens, two Gram-positive bacteria, S. aureus and B. subtilis, two Gram-negative bacteria, E. coli and P. aeruginosa, and a fungus, C. albicans, along with proteolytic stability and high mechanical strength at physiological pH. Overall, we speculate that the discovery of these multifunctional bioinspired materials holds future promise as preferential therapeutics for the remediation of immune-susceptible cancer patients, afflicted by microbial infections arising alone or as side effects of chemotherapeutic medications.

Nanoparticle-Reinforced Hydrogel with a Well-Defined Pore Structure for Sustainable Drug Release and Effective Wound Healing

Impaired chronic wounds are a common complication of diabetes. Inhibited angiogenesis and dysfunctional inflammation render diabetic wound healing a critical challenge. Herein, a sustainable therapeutic composite hydrogel is presented for diabetic wound healing, consisting of a cocktail formulation of anti-inflammatory and local anesthetic nanoparticles incorporated into a composite hydrogel. The surface-modified drug nanoparticles are loaded into the biocompatible hydrogels and cross-linked with a gel precursor to enhance the structure. The sustainable delivery system achieves more than 90% drug release, with a total therapy duration tunable from 4 to 72 h. Through the long-lasting anti-inflammatory and analgesic effects of the composite hydrogel, diabetic wounds are swiftly transitioned into the proliferation phase, augmenting the survival and migration of keratinocytes and facilitating neovascularization and collagen alignment in diabetic wounds. These effects significantly improve the wound healing rate and skin regeneration process, achieving a healing rate that is 17 times that of untreated wounds. This study demonstrates that the hydrogel platform loaded with cocktail drug nanoparticles is promising for the rapid healing of diabetic wounds.

Oxygen-Bonded Amorphous Transition Metal Dichalcogenides with pH-Responsive Reactive Oxygen Biocatalysis for Combined Antibacterial and Anti-inflammatory Therapies in Diabetic Wound Healing

Diabetic wound healing is a formidable challenge, often complicated by biofilms, immune dysregulation, and hindered vascularization within the wound environments. The intricate interplay of these microenvironmental factors has been a significant oversight in the evolution of therapeutic strategies. Herein, the design of an efficient and versatile oxygen-bonded amorphous transition metal dichalcogenide biocatalyst (aRuS-Or) with pH-responsive reactive oxygen biocatalysis for combined antibacterial and anti-inflammatory therapies in promoting diabetic wound healing is reported. Leveraging the incorporation of Ru─O bonds, aRuS-Or exhibits optimized adsorption/desorption behavior of oxygen intermediates, thereby enhancing both the reactive oxygen species (ROS) generation activity in acidic conditions and ROS scavenging performance in neutral environments. Remarkably, aRuS-Or demonstrates exceptional bactericidal potency within infected milieus through biocatalytic ROS generation. Beyond its antimicrobial capability, post-eradication, aRuS-Or serves a dual role in mitigating oxidative stress in inflammatory wounds, providing robust cellular protection and fostering an M2-phenotype polarization of macrophages, which is pivotal for accelerating the wound repair process. The findings underscore the multifaceted efficacy of aRuS-Or, which harmoniously integrates high antibacterial action with anti-inflammatory and pro-angiogenic properties. This triad of functionalities positions aRuS-Or as a promising candidate for the comprehensive management of complex diabetic ulcers, addressing the unmet needs in the current therapeutics.

Development of a pH-Responsive Antimicrobial and Potent Antioxidant Hydrogel for Accelerated Wound Healing: A Game Changer in Drug Delivery

Stimuli-responsive hydrogels have the capability to alter their state in response to changes in physiological signals within their application environment, providing distinct benefits in drug delivery applications. Here, the acidic pH typically found in acutely infected wounds can be effectively managed by incorporating a pH-responsive Ag+ loaded system within the hydrogel, thereby ensuring efficient drug use and preventing potential toxicity from the sudden release of silver ions. The antimicrobial composite hydrogel HAMA/GelMA-CA/Ag+ provides some tissue adhesion and accelerates wound healing. GelMA-CA is synthesized by modifying gelatin methacryloyl (GelMA) with caffeic acid (CA), while hyaluronic acid methacryloyl (HAMA) is introduced to prepare a double network hydrogel. Silver nitrate is then introduced to make it pH-responsive through the formation of coordination between the polyphenolic structure of caffeic acid and the silver ions. The composite hydrogel exhibited excellent antioxidant properties and strong antimicrobial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, the composite hydrogel accelerated the promotion of wound healing in a rat model of S. aureus-infected wounds. In conclusion, the HAMA/GelMA-CA/Ag+ hydrogel is a promising bioactive material that can be used as a wound dressing to promote the healing of acutely infected wounds.

Application of Self-Healing Hydrogels in the Treatment of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IDD) is one of the leading causes of chronic pain and disability, and traditional treatment methods often struggle to restore its complex biomechanical properties. This article explores the innovative application of self-healing hydrogels in the treatment of IDD, offering new hope for disc repair due to their exceptional self-repair capabilities and adaptability. As a key support structure in the human body, intervertebral discs are often damaged by trauma or degenerative changes. Self-healing hydrogels not only mimic the mechanical properties of natural intervertebral discs but also self-repair when damaged, thereby maintaining stable functionality. This article reviews the self-healing mechanisms and design strategies of self-healing hydrogels and, for the first time, outlines their potential in the treatment of IDD. Furthermore, the article looks forward to future developments in the field, including intelligent material design, multifunctional integration, encapsulation and release of bioactive molecules, and innovative combinations with tissue engineering and stem cell therapy, offering new perspectives and strategies for IDD treatment.

Ameliorating macrophage pyroptosis via ANXA1/NLRP3/Caspase-1/GSDMD pathway: Ac2-26/OGP-loaded intelligent hydrogel enhances bone healing in diabetic periodontitis

Craniofacial bone defect healing in periodontitis patients with diabetes background has long been difficult due to increased blood glucose levels which cause overproduction of reactive oxygen species (ROS) and a low pH environment. These conditions negatively affect the function of macrophages, worsen inflammation and oxidative stress, and ultimately, hinder osteoblasts' bone repair potential. In this study, we for the first time found that annexin A1 (ANXA1) expression in macrophages was reduced in a diabetic periodontitis (DP) environment, with the activation of the NLRP3/Caspase-1/GSDMD signaling pathway, and, eventually, increased macrophage pyroptosis. Next, we have developed a new GPPG intelligent hydrogel system which was ROS and pH responsive, and loaded with Ac2-26, an ANXA1 bioactive peptide, and osteogenic peptide OGP as well. We found that Ac2-26/OGP/GPPG can effectively reduce ROS, mitigates macrophage pyroptosis via the ANXA1/NLRP3/Caspase-1/GSDMD pathway and enhanced osteogenic differentiation. The effect of Ac2-26/OGP/GPPG in regulation of pyroptosis and bone defect repair was also further validated by animal experiments on periodontitis-induced tooth loss model in diabetic rats. To conclude, our study unveils the effect of ANXA1 on macrophage pyroptosis in periodontitis patients with diabetes, based on which we introduced a promising innovative hydrogel system for improvement of bone defects repair in DP patients via targeting macrophage pyroptosis and enhancing osteogenic potential.

Mechanism study of Dual-Emission ratiometric fluorescent pH-Sensitive carbon quantum dots and its application on mornitoring enzymatic catalysis

Carbon dots (CQD) have received significant attention as a novel ratiometric fluorescent pH nanoprobe, owing to their favorable optical properties and excellent biocompatibility. Despite their appealing features, the precise mechanism behind the pH-sensitive photoluminescence of CQDs remains to be fully understood. This study endeavors to unravel the mechanism underlying the pH-responsive ratiometric fluorescence in dual-emission CQDs, synthesized through a one-step hydrothermal method using o-phenylenediamine and oxalic acid as precursors. The resultant CQDs exhibit inherent dual-emission at wavelengths of 383 nm and 566 nm, with the ratiometric fluorescence response tailored by the ratio of precursors, providing a robust tool for pH sensing across a range of 2 to 6. Detailed characterizations, including chemical, morphological, and optical analyses, alongside theoretical insights from time-dependent density functional theory (TD-DFT), elucidate the mechanism underlying the pH-dependent luminescence, attributed to the electron cloud transmission between amide and adjacent carboxyl groups on the CQD surface. The superior performance of these CQDs in real-time pH monitoring is demonstrated through their application in glucose oxidase-catalyzed reactions, showcasing their potential as efficient, reliable nanoprobes for biomedical research and diagnostic applications.

Application of an Injectable Thermosensitive Hydrogel Drug Delivery System for Degenerated Intervertebral Disc Regeneration

Intervertebral disc degeneration is characterized by a localized, chronic inflammatory response leading to a synthesis/catabolism imbalance within the nucleus pulposus (NP) and progressive functional impairment within the NP. Polyphenol molecules have been widely used in anti-inflammatory therapies in recent years; therefore, we designed an injectable, temperature-sensitive hydrogel PLGA-PEG-PLGA-based drug delivery system for local and sustained delivery of two drugs tannic acid (TA) and resveratrol (Res), with the hydrogel carrying TA directly and Res indirectly (carried directly by inflammation-responsive nanoparticles). The delivery system presents good injectability at room temperature and forms a gel in situ upon entering the intervertebral disc. The delivery system can rapidly release TA and sustain Res release. In vitro and in vivo experiments have shown that this hydrogel drug delivery system is effective in anti-inflammation of degenerated intervertebral discs and promotes the regeneration of extracellular matrix in the NP.

Electroconductive Nanocellulose, a Versatile Hydrogel Platform: From Preparation to Biomedical Engineering Applications

Nanocelluloses have garnered significant attention recently in the attempt to create sustainable, improved functional materials. Nanocellulose possesses wide varieties, including rod-shaped crystalline cellulose nanocrystals and elongated cellulose nanofibers, also known as microfibrillated cellulose. In recent times, nanocellulose has sparked research into a wide range of biomedical applications, which vary from developing 3D printed hydrogel to preparing structures with tunable characteristics. Owing to its multifunctional properties, different categories of nanocellulose, such as cellulose nanocrystals, cellulose nanofibers, and bacterial nanocellulose, as well as their unique properties are discussed here. Here, different methods of nanocellulose-based hydrogel preparation are covered, which include 3D printing and crosslinking methods. Subsequently, advanced nanocellulose-hydrogels addressing conductivity, shape memory, adhesion, and structural color are highlighted. Finally, the application of nanocellulose-based hydrogel in biomedical applications is explored here. In summary, numerous perspectives on novel approaches based on nanocellulose-based research are presented here.

Smart hydrogel-based trends in future tendon injury repair: A review

Despite advances in tissue engineering for tendon repair, rapid functional repair is still challenging due to its specificity and is prone to complications such as postoperative infections and tendon adhesions. Smart responsive hydrogels provide new ideas for tendon therapy with their flexibly designed three-dimensional cross-linked polymer networks that respond to specific stimuli. In recent years, a variety of smart-responsive hydrogels have been developed for the treatment of tendon disorders, showing great research promise and ability to address complex challenges. This article provides a comprehensive review of recent advances in the field of smart-responsive hydrogels for the treatment of tendon disorders, with a special focus on their response properties to different physical, chemical and biological stimuli. The multiple functional properties of these innovative materials are discussed in depth, including excellent biocompatibility and biodegradability, excellent mechanical properties, biomimetic structural design, convenient injectability, and unique self-healing capabilities. These properties enable the smart-responsive hydrogels to demonstrate significant advantages in solving difficult problems in the treatment of tendon disorders, such as precise drug delivery, tendon adhesion prevention and postoperative infection control. In addition, the article looks at the future prospects of smart-responsive hydrogels and analyses the challenges they may face in achieving widespread application.

Exploring the potential of polysaccharides-based injectable self-healing hydrogels for wound healing applications: A review

In recent decades, significant advancements have been made in wound healing treatments, mainly due to the development of biopolymer-based hydrogels. These injectable self-healing hydrogels have attracted considerable interest because of their unique attributes, including reversible chemistry, injectability, and printability. Unlike traditional hydrogels, injectable polysaccharide-based self-healing hydrogels offer numerous benefits. They can be tailored to fit individual patients, significantly advancing personalized medicine. Upon injection, these hydrogels transform in situ into a substance that effectively covers the entire lesion in all three dimensions, reaching irregular and deep lesions. Injectable self-healing hydrogels also play a pivotal role in promoting tissue regeneration. Their diffusive and viscoelastic properties allow for the controlled delivery of cells or therapeutics in a spatiotemporal manner, provide mechanical support, and facilitate the local recruitment and modulation of host cells. Consequently, these hydrogels have revolutionized innovative approaches to tissue regeneration and are ideally suited for managing chronic wounds. This review paper presents a comprehensive classification of injectable self-healing hydrogels commonly used in chronic wound repair and provides a detailed analysis of the various applications of injectable self-healing hydrogels in treating chronic wounds, thereby illuminating this rapidly evolving field.

Photothermal enhanced antibacterial chitosan-based polydopamine composite hydrogel for hemostasis and burn wound repairing

Bleeding and bacterial infection are common problems associated with wound treatment, while effective blood clotting and vessel regeneration promotion are the primary considerations to design the wound dressing materials. This research presents a chitosan-based hydrogel with grafted quaternary ammonium and polyphosphate (QCSP hydrogel) as the antibacterial hemostatic dressing to achieve burn wound treatment. The tissue adhesion of the hydrogel sealed the blood flow and the polyphosphate grafted to the chitosan promoted the activation of coagulation factor V to enhance the hemostasis. At the same time, the grafted quaternary ammonium enhanced the antibacterial ability of the biodegradable hydrogel wound dressing. In addition, the polydopamine as a photothermal agent was composited into the hydrogel to enhance the antibacterial and reactive oxygen scavenging performance. The in vivo hemostasis experiment proved the polyphosphate enhanced the coagulation property. Moreover, this photothermal property of the composite hydrogel enhanced the burn wound repairing rate combined with the NIR stimulus. As a result, this hydrogel could have potential application in clinic as dressing material for hemostasis and infection prone would repairing.

Endogenous/exogenous stimuli‐responsive smart hydrogels for diabetic wound healing

Diabetes significantly impairs the body's wound‐healing capabilities, leading to chronic, infection‐prone wounds. These wounds are characterized by hyperglycemia, inflammation, hypoxia, variable pH levels, increased matrix metalloproteinase activity, oxidative stress, and bacterial colonization. These complex conditions complicate effective wound management, prompting the development of advanced diabetic wound care strategies that exploit specific wound characteristics such as acidic pH, high glucose levels, and oxidative stress to trigger controlled drug release, thereby enhancing the therapeutic effects of the dressings. Among the solutions, hydrogels emerge as promising due to their stimuli‐responsive nature, making them highly effective for managing these wounds. The latest advancements in mono/multi‐stimuli‐responsive smart hydrogels showcase their superiority and potential as healthcare materials, as highlighted by relevant case studies. However, traditional wound dressings fall short of meeting the nuanced needs of these wounds, such as adjustable adhesion, easy removal, real‐time wound status monitoring, and dynamic drug release adjustment according to the wound's specific conditions. Responsive hydrogels represent a significant leap forward as advanced dressings proficient in sensing and responding to the wound environment, offering a more targeted approach to diabetic wound treatment. This review highlights recent advancements in smart hydrogels for wound dressing, monitoring, and drug delivery, emphasizing their role in improving diabetic wound healing. It addresses ongoing challenges and future directions, aiming to guide their clinical adoption.

Tunicate cellulose nanocrystals strengthened injectable stretchable hydrogel as multi-responsive enhanced antibacterial wound dressing for promoting diabetic wound healing

The intricate microenvironment of diabetic wounds characterized by hyperglycemia, intense oxidative stress, persistent bacterial infection and complex pH fluctuations hinders the healing process. Herein, an injectable multifunctional hydrogel (QPTx) was developed, which exhibited excellent mechanical performance and triple responsiveness to pH, temperature, and glucose due to dynamic covalent cross-linking involving dynamic Schiff base bonds and phenylboronate esters with phenylboronic-modified quaternized chitosan (QCS-PBA), polydopamine coated tunicate cellulose crystals (PDAn@TCNCs) and polyvinyl alcohol (PVA). Furthermore, the hydrogels can incorporate insulin (INS) drugs to adapt to the complex and variable wound environment in diabetic patients for on-demand drug release that promote diabetic wound healing. Based on various excellent properties of the colloidal materials, the hydrogels were evaluated for self-healing, rheological and mechanical properties, in vitro insulin response to pH/temperature/glucose release, antibacterial, antioxidant, tissue adhesion, coagulation, hemostasis in vivo and in vitro, and biocompatibility and biodegradability. By introducing PDAn@TCNCs particles, the hydrogel has photothermal antibacterial activity, enhanced adhesion and oxidation resistance. We further demonstrated that these hydrogel dressings significantly improved the healing process compared to commercial dressings (Tegaderm™) in full-layer skin defect models. All indicated that the glucose-responsive QPTx hydrogel platform has great potential for treating diabetic wounds.

A ROS-Responsive Lipid Nanoparticles Release Multifunctional Hydrogel Based on Microenvironment Regulation Promotes Infected Diabetic Wound Healing

The continuous imbalance of the diabetic wound microenvironment is an important cause of chronic nonhealing, which manifests as a vicious cycle between excessive accumulation of reactive oxygen species (ROS) and abnormal healing. Regulating the microenvironment by suppressing wound inflammation, oxidative stress, and bacterial infection is a key challenge in treating diabetic wounds. In this study, ROS-responsive hydrogels are developed composed of silk fibroin methacrylated (SFMA), modified collagen type III (rCol3MA), and lipid nanoparticles (LNPs). The newly designed hydrogel system demonstrated stable physicochemical properties and excellent biocompatibility. Moreover, the release of antimicrobial peptide (AMP) and puerarin (PUE) demonstrated remarkable efficacy in eradicating bacteria, regulating inflammatory responses, and modulating vascular functions. This multifunctional hydrogel is a simple and efficient approach for the treatment of chronic diabetic infected wounds and holds tremendous potential for future clinical applications.

Chitosan/rutin multifunctional hydrogel with tunable adhesion, anti-inflammatory and antibacterial properties for skin wound healing

Effective wound care remains a significant challenge due to the need for infection prevention, inflammation reduction, and minimal tissue damage during dressing changes. To tackle these issues, we have developed a multifunctional hydrogel (CHI/CPBA/RU), composed of chitosan (CHI) modified with 4-carboxyphenylboronic acid (CPBA) and the natural flavonoid, rutin (RU). This design endows the hydrogel with body temperature-responsive adhesion and low temperature-triggered detachment, thus enabling painless removal during dressing changes. The CHI/CPBA/RU hydrogels exhibit excellent biocompatibility, maintaining over 97 % viability of L929 cells. They also demonstrate potent intracellular free radical scavenging activity, with scavenging ratios ranging from 53 % to 70 %. Additionally, these hydrogels show anti-inflammatory effects by inhibiting pro-inflammatory cytokines (TNF-α, IL-6, and iNOS) and increasing anti-inflammatory markers (Arg1 and CD206) in RAW 264.7 macrophages. Notably, they possess robust antimicrobial properties, inhibiting over 99.9 % of the growth of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus growth. In vivo testing on a murine full-thickness skin defect model shows that the hydrogel significantly accelerates wound healing by reducing inflammation, increasing collagen deposition, and promoting angiogenesis, achieving 98 % healing by day 10 compared to 78 % in the control group. These attributes make the polysaccharide-based hydrogel a promising material for advanced wound care.

Oligolysine-based hydrogel dressing with antibacterial, anti-inflammatory, and tissue-adhesion activities for infected wound treatment

Fabricating injectable hydrogel with multiple functions and effective promotion of wound repair has a great prospect in treatment of bacterial infected wounds. Herein, a pH/reactive oxygen species (ROS) dual responsive injectable hydrogel (PVBDL-gel) was constructed, the PVBDL-gel was cross-linked by dynamic Schiff base bonds and borate ester bonds between poly(vanillin acrylate-co-3 acrylamide phenylboronic acid-co-N,N-dimethylacrylamide) (P(VA-co-AAPBA-co-DMA)), oligolysines and polyvinyl alcohol (PVA). The anti-inflammatory drug, dexamethasone sodium phosphate (DEX), was encapsulated in this hydrogel. The hydrogel exhibited excellent degradability, stable rheology and suitable tissue adhesion, more importantly, which showing pH/ROS responsive ability and controllable releasing of DEX. In vitro and in vivo experiment results showed that the PVBDL-gel with good biocompatibility and efficient anti-infection ability can effectively eradicate 99.9 % of pathogenic bacteria within 3 h and promote the repair and regeneration of bacterial infection wounds. This novel multifunctional injectable hydrogel has great application in the field of bacterial infection wound repair.

Overview of Venous Thromboembolism and Emerging Therapeutic Technologies Based on Nanocarriers-Mediated Drug Delivery Systems

Venous thromboembolism (VTE) is a serious health condition and represents an important cause of morbidity and, in some cases, mortality due to the lack of effective treatment options. According to the Centers for Disease Control and Prevention, 3 out of 10 people with VTE will have recurrence of a clotting event within ten years, presenting a significant unmet medical need. For some VTE patients, symptoms can last longer and have a higher than average risk of serious complications; in contrast, others may experience complications arising from insufficient therapies. People with VTE are initially treated with anticoagulants to prevent conditions such as stroke and to reduce the recurrence of VTE. However, thrombolytic therapy is used for people with pulmonary embolism (PE) experiencing low blood pressure or in severe cases of DVT. New drugs are under development, with the aim to ensure they are safe and effective, and may provide an additional option for the treatment of VTE. In this review, we summarize all ongoing trials evaluating anticoagulant interventions in VTE listed in clinicaltrials.gov, clarifying their underlying mechanisms and evaluating whether they prevent the progression of DVT to PE and recurrence of thrombosis. Moreover, this review summarizes the available evidence that supports the use of antiplatelet therapy for VTE. Since thrombolytic agents would cause off-target effects, targeted drug delivery platforms are used to develop various therapeutics for thrombotic diseases. We discuss the recent advances achieved with thrombus-targeting nanocarriers as well as the major challenges associated with the use of nanoparticle-based therapeutics.

Multifunctional chitosan-based hydrogels loaded with iridium nanoenzymes for skin wound repair

Hemostasis, infection, oxidative stress, and inflammation still severely impede the wound repair process. It is significant to develop multifunctional wound dressings that can function as needed in various stages of wound healing. In this study, iridium nanoparticles (IrNPs) with multi-enzyme mimetic activity were complexed with chitosan (CS) and fucoidan (FD) for the first time to make a multifunctional CS/FD/IrNPs hydrogel with excellent antioxidant effect. The hydrogel has excellent physicochemical properties. In particular, the incorporation of IrNPs imparts excellent antioxidant properties to the hydrogel, which could scavenge reactive oxygen species (ROS). In addition, the hydrogel shows excellent hemostatic and antibacterial properties. The CS/FD/IrNPs hydrogel performs fast and efficient hemostasis in 21 s. Moreover, the blood loss of the CS/FD/IrNPs hydrogel group was approximately 10% of that in the control group and the antibacterial rate of CS/FD/IrNPs hydrogel against E. coli and S. aureus was up to 95 %. In vivo results demonstrate that CS/FD/IrNPs hydrogel promotes wound healing by attenuating ROS levels, reducing oxidative damage, mitigating inflammation, and accelerating angiogenesis. To summarize, the CS/FD/IrNPs hydrogel system, with hemostatic, antibacterial, antioxidant, anti-inflammatory and pro-healing activities, can be a promising and effective strategy for the treatment of clinically difficult-to-heal wounds.

A gold nanoparticle-based photothermal hydrogel assisted by an N-halamine polymer for bacteria-infected skin wound healing

Bacteria-infected wounds and antibiotic misuse have become a challenge in the treatment of clinical infections. Therefore, there is an urgent need to design non-antibiotic-dependent multifunctional wound dressings for the treatment of bacterially infected wounds. In this study, an injectable antibacterial hydrogel (pAMPS-Cl/AuNR@HA-DA) based on gold nanorods (AuNR) and N-halamine (pAMPS-Cl) with significant photothermal antibacterial properties was developed. The obtained pAMPS-Cl/AuNR@HA-DA hydrogel showed a sponge-like structure with excellent injectability, self-healing, tissue adhesion, and good hemocompatibility. In addition, the hydrogel exhibited excellent in vitro antibacterial capacity under near-infrared (NIR) laser irradiation through the synergistic action of photothermal therapy (PTT) and chemical release therapy. It also showed an excellent ability to eliminate bacterial infection and promote wound healing, indicating that the pAMPS-Cl/AuNR@HA-DA composite hydrogel could be a promising dressing for the treatment of skin wounds.

Stimuli-responsive drug delivery systems for inflammatory skin conditions

Inflammatory skin conditions highly influence the quality of life of the patients suffering from these disorders. Symptoms include red, itchy and painful skin lesions, which are visible to the rest of the world, causing stigmatization and a significantly lower mental health of the patients. Treatment options are often unsatisfactory, as they suffer from either low patient adherence or the risk of severe side effects. Considering this, there is a need for new treatments, and notably of new ways of delivering the drugs. Stimuli-responsive drug delivery systems are able to deliver their drug cargo in response to a given stimulus and are, thus, promising for the treatment of inflammatory skin conditions. For example, the use of external stimuli such as ultraviolet light, near infrared radiation, or alteration of magnetic field enables drug release to be precisely controlled in space and time. On the other hand, internal stimuli induced by the pathological condition, including pH alteration in the skin or upregulation of reactive oxygen species or enzymes, can be utilized to create drug delivery systems that specifically target the diseased skin to achieve a better efficacy and safety. In the latter context, however, it is of key importance to match the trigger mechanism of the drug delivery system to the actual pathological features of the specific skin condition. Hence, the focus of this article is placed not only on reviewing stimuli-responsive drug delivery systems developed to treat specific inflammatory skin conditions, but also on critically evaluating their efficacy in the context of specific skin diseases. STATEMENT OF SIGNIFICANCE: Skin diseases affect one-third of the world's population, significantly lowering the quality of life of the patients, who deal with symptoms such as painful and itchy skin lesions, as well as stigmatization due to the visibility of their symptoms. Current treatments for inflammatory skin conditions are often hampered by low patient adherence or serious drug side effects. Therefore, more emphasis should be placed on developing innovative formulations that provide better efficacy and safety for patients. Stimuli-responsive drug delivery systems hold considerable promise in this regard, as they can deliver their cargo precisely where and when it is needed, reducing adverse effects and potentially offering better treatment outcomes.

Microneedle transdermal drug delivery as a candidate for the treatment of gouty arthritis: Material structure, design strategies and prospects

Gouty arthritis (GA) is caused by monosodium urate (MSU) crystals deposition. GA is difficult to cure because of its complex disease mechanism and the tendency to reoccur. GA patients require long-term uric acid-lowering and anti-inflammatory treatments. In the past ten years, as a painless, convenient and well-tolerated new drug transdermal delivery method, microneedles (MNs) administration has been continuously developed, which can realize various drug release modes to deal with various complex diseases. Compared with the traditional administration methods (oral and injection), MNs are more conducive to the long-term independent treatment of GA patients because of their safe, efficient and controllable drug delivery ability. In this review, the pathological mechanism of GA and common therapeutic drugs for GA are summarized. After that, MNs drug delivery mechanisms were summarized: dissolution release mechanism, swelling release mechanism and channel-assisted release mechanism. According to drug delivery patterns of MNs, the mechanisms and applications of rapid-release MNs, long-acting MNs, intelligent-release MNs and multiple-release MNs were reviewed. Additionally, existing problems and future trends of MNs in the treatment of GA were also discussed. STATEMENT OF SIGNIFICANCE: Gout is an arthritis caused by metabolic disease "hyperuricemia". Epidemiological studies show that the number of gouty patients is increasing rapidly worldwide. Due to the complex disease mechanism and recurrent nature of gout, gouty patients require long-term therapy. However, traditional drug delivery modes (oral and injectable) have poor adherence, low drug utilization, and lack of local localized targeting. They may lead to adverse effects such as rashes and gastrointestinal reactions. As a painless, convenient and well-tolerated new drug transdermal delivery method, microneedles have been continuously developed, which can realize various drug release modes to deal with gouty arthritis. In this review, the material structure, design strategy and future outlook of microneedles for treating gouty arthritis will be reviewed.

Injectable Oxygen-Carrying Microsphere Hydrogel for Dynamic Regulation of Redox Microenvironment of Wounds

The delayed healing of infected wounds can be attributed to the increased production of reactive oxygen species (ROS) and consequent damages to vascellum and tissue, resulting in a hypoxic wound environment that further exacerbates inflammation. Current clinical treatments including hyperbaric oxygen therapy and antibiotic treatment fail to provide sustained oxygenation and drug-free resistance to infection. To propose a dynamic oxygen regulation strategy, this study develops a composite hydrogel with ROS-scavenging system and oxygen-releasing microspheres in the wound dressing. The hydrogel itself reduces cellular damage by removing ROS derived from immune cells. Simultaneously, the sustained release of oxygen from microspheres improves cell survival and migration in hypoxic environments, promoting angiogenesis and collagen regeneration. The combination of ROS scavenging and oxygenation enables the wound dressing to achieve drug-free anti-infection through activating immune modulation, inhibiting the secretion of pro-inflammatory cytokines interleukin-6, and promoting tissue regeneration in both acute and infected wounds of rat skins. Thus, the composite hydrogel dressing proposed in this work shows great potential for dynamic redox regulation of infected wounds and accelerates wound healing without drugs.

Mitochondria-engine with self-regulation to restore degenerated intervertebral disc cells via bioenergetic robust hydrogel design

Previous studies have confirmed that intervertebral disc degeneration (IDD) is closely associated with inflammation-induced reactive oxygen species (ROS) and resultant cell mitochondrial membrane potential (MMP) decline. Clearance of ROS in an inflammatory environment is essential for breaking the vicious cycle of MMP decline. Additionally, re-energizing the mitochondria damaged in the inflammatory milieu to restore their function, is equally important. Herein, we proposed an interesting concept of mitochondrion-engine equipped with coolant, which enables first to "cool-down" the inflammatory environment, next to restore the MMP, finally to allow cells to regain normal energy metabolism through materials design. As such, we developed a multi-functional composite composed of a reactive oxygen species (ROS)-responsive sodium alginate/gelatin hydrogel infused into a rigid 3D-printed thermoplastic polyurethane (TPU) scaffold. The TPU scaffold was coated with conductive polypyrrole (PPy) to electrophoretically deposit l-arginine, which could upregulate the Mammalian target of rapamycin (mTOR) pathway, thus increasing MMP and energy metabolism to stimulate extracellular matrix synthesis for IVD repair. While the ROS-responsive hydrogel acting as the "mito-engine coolant" could scavenge the excessive ROS to create a favorable environment for IVD cells recovery. Demonstrated by in vitro and in vivo evaluations, the mito-engine system markedly promoted the proliferation and collagen synthesis of nucleus pulposus cells while enhancing the mitochondrial respiration and MMP under oxidative stress. Radiological and histological assessments in vivo revealed the efficacy of this system in IVD repair. This unique bioinspired design integrated biomaterial science with mitochondrial biology, presents a promising paradigm for IDD treatment.

A Descriptive Review on the Potential Use of Diatom Biosilica as a Powerful Functional Biomaterial: A Natural Drug Delivery System

Although various chemically synthesized materials are essential in medicine, food, and agriculture, they can exert unexpected side effects on the environment and human health by releasing certain toxic chemicals. Therefore, eco-friendly and biocompatible biomaterials based on natural resources are being actively explored. Recently, biosilica derived from diatoms has attracted attention in various biomedical fields, including drug delivery systems (DDS), due to its uniform porous nano-pattern, hierarchical structure, and abundant silanol functional groups. Importantly, the structural characteristics of diatom biosilica improve the solubility of poorly soluble substances and enable sustained release of loaded drugs. Additionally, diatom biosilica predominantly comprises SiO2, has high biocompatibility, and can easily hybridize with other DDS platforms, including hydrogels and cationic DDS, owing to its strong negative charge and abundant silanol groups. This review explores the potential applications of various diatom biosilica-based DDS in various biomedical fields, with a particular focus on hybrid DDS utilizing them.

Notch-Targeted Therapeutic in Colorectal Cancer by Notch1 Attenuation Via Tumor Microenvironment-Responsive Cascade DNA Delivery

The Notch signaling is a key molecular pathway that regulates cell fate and development. Aberrant Notch signaling can lead to carcinogenesis and progression of malignant tumors. However, current therapies targeting Notch pathway lack specificity and induce high toxicity. In this report, a tumor microenvironment-responsive and injectable hydrogel is designed to load plasmid DNA complexes as a cascade gene delivery system to achieve precise Notch-targeted gene therapy of colorectal cancer (CRC). The hydrogels are prepared through cross-linking between phenylboric acid groups containing poly(oligo(ethylene glycol)methacrylate) (POEGMA) and epigallocatechin gallate (EGCG), used to load the complexes between plasmid DNA encoding short hairpin RNAs of Notch1 (shNotch1) and fluorinated polyamidoamine (PAMAM-F) (PAMAM-F/shNotch1). In response to low pH and H2O2 in tumor microenvironment, the hydrogel can be dissociated and release the complexes for precise delivery of shNotch1 into tumor cells and inhibit Notch1 activity to suppress malignant biological behaviors of CRC. In the subcutaneous tumor model of CRC, PAMAM-F/shNotch1-loaded hydrogels can accurately attenuate Notch1 activity and significantly inhibit tumor growth without affecting Notch signal in adjacent normal tissues. Therefore, this therapeutic system can precisely inhibit Notch1 signal in CRC with high responsiveness and low toxicity, providing a promising Notch-targeted gene therapeutic for human malignancy.