Directed self-assembly of herbal small molecules into sustained release hydrogels for treating neural inflammation

A multifunctional hydrogel loaded with magnesium-doped bioactive glass-induced vesicle clusters enhances diabetic wound healing by promoting intracellular delivery of extracellular vesicles

The treatment of diabetic wounds (DWs) poses a significant medical challenge. Mesenchymal stem cell-derived small extracellular vesicles (sEVs) have demonstrated potential in accelerating healing by delivering growth factors and microRNAs. However, the rapid clearance by the circulatory system limits their concentration and bioavailability within cells. This study employed magnesium-doped bioactive glass (MgBG) to autonomously program sEVs into a vesicle cluster (EPPM), which was subsequently incorporated into a hydrogel to create a comprehensive repair system that enhanced the delivery of both sEVs and MgBG, thereby promoting rapid healing of diabetic wounds. This hydrogel exhibited excellent injectable, self-healing and bioadhesive properties, making it an ideal physical barrier for DWs. In addition, the hydrogels also possessed photoresponsive properties that facilitated their bactericidal activity. The released EPPM significantly increased the intracellular uptake and accumulation of sEVs, with approximately 8.2-fold enhancement in macrophages and 16.7-fold in endothelial cells. The EPPM clusters efficiently induce macrophage M2 polarization, reduce inflammatory responses at the wound site, and recruit cells, thereby promoting angiogenesis and collagen deposition. This integrated repair system provided a new platform for the comprehensive treatment of diabetic wounds.

Anti-neuroinflammatory agent rhein lysinate-based self-assembled injectable hydrogel loaded with ZL006 for promoting post-stroke functional recovery

The therapeutic agent-based self-assembled hydrogel is gaining interest for biomedical applications, because it overcomes the poor biodegradability and low therapeutic agent loading of conventional polymer gelator-based hydrogel. Here, we present rhein lysinate (RHL), a therapeutic agent that self-assembles to form a stable hydrogel through the π-π stacking and hydrogen bonding interactions, while also exerting anti-neuroinflammatory effect. As a small molecular hydrogelator, RHL has significantly improved water solubility and enhanced self-assembly and gelation capabilities compared to the natural anthraquinone rhein. The relaxed gel-forming conditions enhance the practical application potential of self-assembled hydrogel of RHL (RHL gel). The RHL gel can be loaded with the bioactive agents such as 5-Fluorouracil, temozolomide, edaravone, and ZL006, mainly based on efficient stacking between aromatic rings in the bioactive agents and anthraquinone rings in the hydrogel network structure. The pre-gelled RHL gel and ZL006-loaded RHL gel (ZL006-RHL gel) exhibit shear-thinning behavior, flowing like a liquid under high shear stress during injection. Once this shear stress is removal within the body, they rapidly recover to the initial solid-like state. When a single dose of ZL006-RHL gel is administrated to stroke cavity in the subacute phase of stroke, RHL gel matrix effectively reduces post-stroke neuroinflammation, creates a favorable environment for ZL006 to enhance neuroplasticity, and confers a sustained and stable action to ZL006, leading to a long-lasting improvement of motor performance. This study may provide a valuable strategy for therapeutic intervention to promote post-stroke functional recovery, for which there are no clinically available drugs.

Hydrogel adhesives for tissue recovery

Hydrogel adhesives (HAs) are promising and rewarding tools for improving tissue therapy management. Such HAs had excellent properties and potential applications in biological tissues, such as suture replacement, long-term administration, and hemostatic sealing. In this review, the common designs and the latest progress of HAs based on various methodologies are systematically concluded. Thereafter, how to deal with interfacial water to form a robust wet adhesion and how to balance the adhesion and non-adhesion are underlined. This review also provides a brief description of gelation strategies and raw materials. Finally, the potentials of wound healing, hemostatic sealing, controlled drug delivery, and the current applications in dermal, dental, ocular, cardiac, stomach, and bone tissues are discussed. The comprehensive insight in this review will inspire more novel and practical HAs in the future.

Sinomenine-glycyrrhizic acid self-assembly enhanced the anti-inflammatory effect of sinomenine in the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a common chronic systemic autoimmune disease that causes cartilage and bone damage in multiple joints, ultimately leading to disability. There is an urgent need to develop multidimensional strategies to treat RA. Sinomenine (SIN) has the distinctive pharmacological activity in treating RA, but its broader clinical application is limited by its exceedingly short half-life and adverse digestive tract effects. To overcome this obstacle, a self-assembled nanohydrogel (S-G hydrogel) was designed and produced with sinomenine (SIN) and glycyrrhizic acid (GA) without carriers or catalysts through noncovalent bonding. The S-G hydrogel could promote the absorption of SIN probably by protecting SIN from releasing and degrading in the acid circumstances. Oral intake of the S-G hydrogel significantly suppressed the overactivation of neutrophil via the Nf-κb and Mapk pathways in mice with RA. Furthermore, the S-G hydrogel regulated neutrophil activity by reversing apoptosis delay and decreasing autophagy-dependent NET formation. In summary, this study presents a self-assembled hydrogel with promising potential for clinical application, and offers a novel strategy to develop new drugs from the existing patent medicine composed of compounds from traditional Chinese medicine, as well as a special insight to elucidate the herb-matching mechanism in decoction prescriptions.

Transdermal anti-inflammatory effects and mechanisms of hydrogel patches containing seco-iridoids from Gentiana macrophylla Pall

Gentiana macrophylla Pall. (GMP), known as "Qinjiao" in the Chinese Pharmacopeia, has a long history of clinical application in treating rheumatoid arthritis, primarily due to its iridoid components. However, the transdermal anti-inflammatory efficacy, active ingredients, and underlying mechanisms of these components remain under-investigated. This study aimed to clarify the transdermal anti-inflammatory effects and mechanisms of seco-iridoids from GMP by establishing a hydrogel patch transdermal drug delivery system. Using crude and refined GMP iridoid extracts as active components, the hydrogel patch system was established based on physicochemical properties, skin irritation tests, in vitro drug release, and skin permeation. The anti-inflammatory efficacy of these iridoid hydrogel patches was assessed using a carrageenan-induced paw edema model in mice. Content analysis and skin permeation studies identified gentiopicroside (GPS) and swertiamarin (SWE) as the key bioactive constituents. The hydrogel patch system demonstrated superior skin permeation and sustained drug release profiles compared to oral administration, addressing issues of poor bioavailability and rapid metabolism. Mechanistic studies revealed that these seco-iridoids exert their anti-inflammatory effects primarily through modulation of the iNOS/COX-2/NF-κB signaling cascade. Pharmacokinetic evaluations showed significant improvements in bioavailability and prolonged drug release, highlighting the clinical advantages of the transdermal approach. This work lays a solid foundation for the further optimization and clinical translation of GMP-based transdermal formulations, providing a framework for the investigation of iridoid transdermal systems and their therapeutic applications in inflammatory conditions.

EGR1-Driven Re-Epithelialization Enabled by Rutin-Based Self-Assembled Hydrogel Platform for Oral Ulcer Therapy

Oral ulcer (OU) is a highly prevalent mucosal disease characterized by persistent epithelial disruption. The primary challenge in its prolonged healing process is the disorder of re-epithelialization. This study develops a self-assembled hydrogel platform based on the natural small molecule rutin, which overcomes the re-epithelialization barrier through the synergistic effects of early growth response factor 1 (EGR1) gene programming and microenvironment remodeling. In this hydrogel, rutin formed supramolecular structures via hydrogen bonds and π-π interactions without structural modification. In vitro experiments confirm that rutin-based self-assembled hydrogel (RUTG) possesses excellent sustained-release properties and biocompatibility. Moreover, RUTG specifically regulates the transcriptional activation and translation of EGR1, thereby mediating the expression of re-epithelialization-related protein SOX9, and ultimately accelerating cell proliferation and migration as well as promoting re-epithelialization. Additionally, RUTG demonstrates beneficial anti-inflammatory and antioxidant properties, effectively remodeling the local microenvironment. In vivo studies using an oral ulcer model further confirm that RUTG could significantly accelerate the re-epithelialization process, shorten the ulcer healing cycle, and achieve functional tissue reconstruction. Collectively, this carrier-free hydrogel system, which integrates gene programming with microenvironment modulation to achieve efficient re-epithelialization, holds promise for introducing novel approaches to the treatment of oral ulcers.

Calycosin-7-glucoside-Loaded Hydrogel Promotes Wound Healing in Gestational Diabetes Mellitus

The prevalence of gestational diabetes mellitus (GDM) is currently on the rise globally, which heightens the risk of adverse pregnancy outcomes and subsequently increases the likelihood of cesarean delivery. GDM can induce hyperglycemic conditions in cesarean wounds, leading to delayed wound healing and complications such as itching, pain, and scarring. These complications significantly impact the quality of life and mental health of mothers. Furthermore, there is a lack of effective clinical prevention strategies. Consequently, the need to improve wound healing after cesarean sections in women with GDM is a pressing concern that warrants our attention. To maximize the therapeutic impact and extend the bioavailability of calycosin-7-glucoside (CG), it was integrated into a hybridized hydrogel (GOHA) as a drug carrier to create the GOHACG hydrogel. Bases on our tests, the GOHACG hydrogel demonstrated a strong capacity for water absorption, appropriate pore size, and good biocompatibility to adjust to the in situ surroundings of the wound. GOHACG also promoted epidermal regeneration, collagen deposition, angiogenesis, and the conversion of macrophages from the M1 to M2 phenotype. Indicating a reduction in the inflammatory response, accelerated wound repair, and minimized skin scarring in a postcesarean delivery model involving gestational diabetic mellitus mice. In brief, the GOHACG possesses significant properties that enhance wound healing in GDM model, suggesting its potential effects in treating wound healing of GDM.

Atomic Insights Into Self-Assembly of Zingibroside R1 and its Therapeutic Action Against Fungal Diseases

Natural products are a crucial resource for drug discovery, but poor understanding of the molecular-scale mechanisms of their self-assembly into soluble, bioavailable hydrogels limits their applications and therapeutic potential. It is demonstrated that Zingibroside R1 (ZR1), derived from Panax notoginseng, undergoes spontaneous self-assemble into a hydrogel comprising helical nanofibrils with potent antifungal activity lacking in its monomeric state. Cryogenic electron microscopy (cryo-EM) revealed an intricate hydrogen-bonding network that facilitates ZR1 nanofibril formation, characterized by a hydrophobic core and hydrophilic exterior architecture, which underpin its binding activity with cell wall in the vulvovaginal candidiasis (VVC) pathogen, C. albicans. The hydrogen-bonding interface between ZR1 gel and glucan compromises membrane integrity, inhibiting C. albicans proliferation in vitro and in VVC model mice in vivo. ZR1 gel could also deliver probiotic Lactobacillus, synergistically inhibiting VVC and restoring the vaginal microenvironment. This study advances the mechanistic understanding of ZR1's structure-function relationships, offering valuable insights into the rational design and therapeutic optimization of natural product-based hydrogels.

Advancing the Identification of Bioactive Molecules and the Construction of a Synergistic Drug Delivery System in Combating Lung Injury

In recent years, pneumonia caused by multiple viruses has posed a significant threat to public health, particularly affecting vulnerable populations such as the elderly and immunocompromised individuals. Current treatments primarily focused on antiviral medications, lacking "miracle cure" and innovative approaches for the pathological damage caused by viruses. Since 2019, Traditional Chinese Medicine (TCM) has shown remarkable efficacy in treating coronavirus disease 2019 (COVID-19). However, the application is hindered by intricate mechanisms, variable quality, and slow onset. Clinically, Ge-Gen Decoction (GGD) effectively reduced the severity in patients with viral infections. Taking COVID-19 as a case, the bioactive ingredients from GGD: glabridin (GLA) and puerarin (PUE) are identified. Interestingly, it was discovered that PUE can self-assemble into a 3D hydrogel structure upon heating and cooling, namely PUE@gel. This process mirrored the formation of gel-like precipitates in GGD post-decoction. Motivated by this phenomenon, a decoction-mimicking drug delivery system, glabridin─puerarin self-assembled hydrogel (GLA-PUE@gel) was constructed, which exhibits strong anti-inflammatory and antioxidant properties, comparable to GGD at the same dosage. Additionally, PUE that has a high biosafety threshold can competitively bind to angiotensin converting enzyme 2 (ACE2) on host cells, preventing SARS-CoV-2 from invading. This study offered a promising approach for treating virus-induced lung injury.

An antioxidant, antibacterial, and immunoregulatory konjac glucomannan-based nanocomposite hydrogel for promoting skin wound healing

Managing open skin wounds remains a notable challenge in clinical practice, with wound dressings gradually becoming an essential strategy for such treatment. To effectively regulate the wound healing microenvironment, we developed an antibiotic-free nanocomposite hydrogel by combining guanosine-based supramolecular G-quadruplexes (G4), angiogenic deferoxamine (DFO), konjac glucomannan (KGM), and zinc ions through a one-pot mixing strategy. The borate esters in G4 endow the hydrogel with a strong radical-scavenging ability. As a mannose-containing polysaccharide, KGM does not affect the self-assembly of G-quartets and also induces macrophage polarization toward the anti-inflammatory M2 phenotype without requiring expensive exogenous cytokines. Zinc ions were introduced to enhance the hydrogel's mechanical properties by forming coordination interactions with DFO and endowing the hydrogel with excellent antibacterial properties. Collectively, this biocompatible hydrogel accelerates skin wound closure and promotes mature tissue regeneration by stimulating macrophage polarization toward the M2 phenotype, expediting collagen deposition, alleviating inflammation, and enhancing angiogenesis. Overall, this multifunctional hydrogel can serve as a versatile wound dressing material in regenerative medicine.

Calcium-ion-driving assembly of polysaccharide deriving from Zizyphus jujuba to hemostatic hydrogel for treating diabetic wound

Due to good biocompatibility and biodegradable, natural polysaccharide-based hydrogels have received worldwide attentions, where polysaccharide polymers were usually chemically modified to meet the specific elastic requirements. However, it remained highly challenging to develop polysaccharide-based hydrogels with desired mechanical properties and biological functions devoid of any structural modifications. Herein, with the coordination of Ca2+ (15.0 mM), the jujuba polysaccharide (JPS, 1 %) was facilely fabricated to a hydrogel (JPS-gel) within 1 min at pH 10, where the residual proteins also played crucial roles on the assembly. The JPS-gel showed outstanding stability and mechanical properties, which were tunable by adjusting the content of Ca2+/JPS. The JPS-gel also revealed excellent biocompatibility, and could expedite the migration and proliferation of healing-related cells, angiogenesis and alleviate inflammation response. More interestingly, the JPS-gel had hemostatic capacity, where the hemostatic time and blood loss in liver incision model were 13 ± 3 s and 6.3 ± 1.6 mg after 120 s treatment with JPS-gel, respectively. All these superiorities endowed JPS-gel high performance healing in diabetic wounds (10 days). Specially, the expressions of inflammation-related genes were downregulated, but gene expressions associated with cell migration and proliferation, and angiogenesis were upregulated, thus uncovering the action mechanism of JPS-gel on accelerating wound contraction.

Mechanistic exploration of licorice reconciling Medicine:Huangqi Guizhi Wuwu decoction and Shaoyao Gancao decoction compatibility as an example

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza uralensis Fisch. (GU) is a pivotal botanical in traditional Chinese medicine (TCM), because of its ability to reconcile various herbs, and its crucial role in numerous formulas. Huanggui Shaogan decoction (HSGD) is an empirical formula, developed by Huangqi Guizhi Wuwu decoction (HGD) and Shaoyao Gancao decoction (SGD), and prepared by adding GU to HGD. However, the mechanisms of GU reconciling medicine remain incompletely characterized.

AIM OF THE STUDY

This study aimed to explain mechanisms of GU reconciling medicine based on the differences of components, pharmacological efficacy, and the existence of the components.

METHODS

Differential components between HSGD and HGD were systematically identified using LC‒MS/MS coupled with chemometric analysis. The existence states and binding affinities of these differential components were further characterized via ultrafiltration separation. The therapeutic potential of HSGD was validated in a murine model of oxaliplatin-induced peripheral neuropathy (OIPN).

RESULTS

Twenty-two differential chemical components between HSGD and HGD were identified, including flavonoids, saponins, gingerol, and monoglycoside. The transmittance of flavonoids and gingerols increased in HSGD. However, the transmittance of astragalus saponins decreased, which may be due to micelle association and the increase in molecular clusters. HSGD could enhance the mechanical pain threshold, alleviate cold nociceptive hypersensitivity, relieve dorsal root ganglia neuron injury, and decrease the expression of nerve growth factor, 5-hydroxytryptamine, substance P, and calcitonin gene-related peptide better. The differential correlation analysis revealed the relationship between differential components and pharmacological indicators. The above results indicated that different herbs combinations had a greater impact on the dissolution and molecular state of the components of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao.

CONCLUSION

The study highlights the solubilizing effect of GU within HSGD, and it also improves the efficacy of the treatment of OIPN, which underpins its compatibility rationality. It provided an inspiration for the study of other TCM formulas.

Self-assembling chemodrug fiber-hydrogel for transarterial chemoembolization and radiotherapy-enhanced antitumor immunity

Hydrogel, as a promising embolic material for hepatocellular carcinoma (HCC), may fully embolize both major vessels and peripheral microvessels. A self-assembling hydrogel composed of chemotherapeutic drugs offers significant clinical benefits without carrier introduction. Herein, we developed a sustained drug-releasing complex hydrogel (RKT@gel), which was fabricated by the self-assembly of raltitrexed chemotherapeutic drugs (R@gel), along with the incorporation of kaempferol and tantalum nanoparticles (Ta NPs). Kaempferol enhances the mechanical strength of R@gel and inhibits hypoxia-induced angiogenesis post-embolization, improving embolization effectiveness. In addition to enabling X-ray-guided transarterial chemoembolization (TACE), Ta NPs enhance radiation sensitivity. These synergistic effects of RKT@gel not only significantly induce immunogenic cell death, thereby enhancing the activation of dendritic cells, but also activate major histocompatibility complex class I (MHC-I)-mediated antitumor immune recognition and cytotoxicity. In vivo, RKT@gel achieves enhanced tumor deposition and sustained drug release, effectively suppressing tumor progression. Additionally, when combined with radiotherapy, RKT@gel achieves efficient antitumor immunoactivation. Overall, this versatile composite hydrogel not only achieves effective embolization therapy but also substantially triggers antitumor immune responses with good biocompatibility. This multifunctional design provides a TACE-based multidisciplinary strategy for HCC.

Post-Stroke Recovery: A Review of Hydrogel-Based Phytochemical Delivery Systems

Stroke remains a leading cause of disability worldwide, underscoring the urgent need for novel and innovative therapeutic strategies to enhance neuroprotection, support regeneration, and improve functional recovery. Previous research has shown that phytochemicals such as curcumin, tannic acid, gallic acid, ginsenosides, resveratrol, and isorhamnetin display extensive neuroprotective properties, including antioxidant, anti-inflammatory, and anti-apoptotic effects. These natural compounds could also promote neurogenesis, angiogenesis, and the preservation of the blood-brain barrier. Despite their promising bioactivities, clinical application is often limited by poor solubility, bioavailability, and suboptimal pharmacokinetics. Hydrogels offer a promising solution by encapsulating and controlling the gradual release of these phytochemicals directly at the site of injury. Recent advancements in hydrogel formulations, constructed from biopolymers and functionalized using nanotechnological approaches, could significantly improve the solubility, stability, and targeted delivery of phytochemicals. Controlled release profiles from pH-sensitive and environment-responsive hydrogels could ensure that the compounds' therapeutic effects are optimally timed with individual and critical stages of post-stroke repair. Moreover, hydrogel scaffolds with tailored material properties and biocompatibility can create a favorable microenvironment, reducing secondary inflammation, enhancing tissue regeneration, and potentially improving functional and cognitive outcomes following stroke. This review explores the potential of integrating phytochemicals within hydrogel-based delivery systems specifically designed for post-stroke recovery. The design and synthesis of biocompatible, biodegradable hydrogels functionalized especially with phytochemicals and their applications are also discussed. Lastly, we emphasize the need for additional robust and translatable preclinical studies.

Review on application of silk fibroin hydrogels in the management of wound healing

Wounds are regarded as disruptions in the integrity of human skin tissues, and the process of wound healing is often characterized as protracted and complex, primarily due to the potential infection or inflammation caused by microorganisms. The quest for innovative solutions that accelerate wound healing while prioritizing patient safety and comfort has emerged as a focal point. Within this pursuit, silkworm silk fibroin-a natural polymer extracted from silk cocoons-exhibits a distinctive combination of properties including biocompatibility, biodegradability, superior mechanical strength, water absorption, and low immunogenicity, which align closely with the demands of contemporary wound care. Its remarkable biocompatibility facilitates seamless integration with host tissues, thereby minimizing the risk of rejection or adverse reactions. Furthermore, its intrinsic degradability permits controlled release of therapeutic agents, promoting an optimal microenvironment conducive to healing. This review investigates the multifaceted potential of silk fibroin specifically as a wound dressing material and examines the intricate nuances associated with its application in hydrogels for wound healing, aiming to furnish a thorough overview for both researchers and clinicians. By scrutinizing underlying mechanisms, current applications, and prospective directions, we aspire to cultivate new insights and inspire innovative strategies within this rapidly evolving field.

Recent Advances in the Application of Hydrogels as Drug Carriers in Inflammatory Bowel Disease: A Review

Inflammatory bowel disease (IBD) is a chronic and refractory disease with increasing incidence, adversely impacting millions of patients worldwide. Current therapeutic strategies for IBD often exhibit considerable adverse effects, limited efficacy, and a high tendency for recurrence, highlighting the urgent need for novel therapeutic agents. Hydrogel, a three-dimensional hydrophilic network polymer material known for its excellent biocompatibility and responsiveness to stimuli, has been effectively utilized as a drug carrier across various therapeutic systems. The hydrogels' application in IBD treatment holds significant promise for enhancing therapeutic outcomes. This review synthesizes recent advancements in leveraging hydrogels as drug carriers for IBD management. The discussion encompasses the response mechanisms of hydrogels, their application in IBD therapy, and methods of administration. As drug delivery matrices, hydrogels exhibit considerable potential for treating IBD.

Design of indomethacin novel small molecule hydrogels for concomitant release and permeability increases

With the expansion of gel research, organic small molecule gels are beginning to gain attention. Whether the small-molecule gel approach can be a new formulation strategy of solubilization and permeation promotion for poorly soluble drugs needs to be explored in this study. The model ingredient indomethacin (IND) as a nonsteroidal anti-flammatory drug shows limited therapeutic application mainly due to its low water solubility. Herein, the IND small molecule hydrogel was design to co-formed with a small molecule ligand by integrating theory-model-experiment techniques. Then, the formed IND small molecule hydrogels (i.e., IND-MEG hydrogel and IND-ARG hydrogel) with meglumine (MEG) or arginine (ARG) appeared typical 3-D network with good rheology. In comparison to crystalline IND, the solubilities of IND-MEG hydrogel and IND-ARG hydrogel exhibited 506.71-fold and 479.63-fold improvements, respectively. Meanwhile, both IND hydrogels performed significantly enhanced release rate and degree, and maintained supersaturation for a long time arising from the complexation reaction of IND and ligand, which was revealed by phase solubility and fluorescence quenching studies. Furthermore, the designed IND hydrogels significantly promoted IND membrane permeability compared to the commercial IND hydrogel, and enhanced the development potential of novel IND hydrogels for oral and transdermal applications. Therefore, this study provides a new formulation technique to increase the solubility/release and permeability of poorly water-soluble drugs by designing their small molecule hydrogel systems.

A New Screening Strategy for Flavonoid Components to Obtain a Satisfactory Co-Amorphous System with Piperine

Flavonoids are a large class of compounds with a variety of biological activities. Nevertheless, their therapeutic application remains limited due to the generally low water solubility. In the present study, an integrated approach was provided to guide the design of flavonoid co-amorphous systems co-formed with piperine (PIP). Firstly, 7 flavonoid compounds showed good miscibility with PIP from 13 flavonoid candidates. Then, molecular dynamics simulation confirmed hydrogen bond formation between 5 flavonoid compounds (i.e., BAI, HES, ISO, NAR and KAE) and PIP. Herein, 5 flavonoid compounds were successfully co-amorphized with PIP by the melting and quench cooling method, which were proved via PLM, PXRD and DSC measurements. FTIR results showed the potential hydrogen bond interactions between -OH of flavonoid molecules and C = O of PIP molecule in the formed co-amorphous systems, which were consistent with RDF analyses in molecular models. For dissolution tests, 4 co-amorphous systems (i.e., BAI-PIP CM, HES-PIP CM, ISO-PIP CM and NAR-PIP CM) appeared abnormally reduced dissolution compared to their original crystalline counterparts arising from the formation of gels during dissolution, while only KAE-PIP CM displayed significantly enhanced dissolution (5.83-fold of crystalline KAE at 12 h) with long-time supersaturated concentration. Meanwhile, KAE-PIP CM kept physically stable at least 3 months under 25°C and 40°C conditions, and possessed excellent physical stability over individual amorphous components, which was attributed to the stronger intermolecular interaction by higher binding energy analysis. Therefore, this study provides a design strategy to guide the screening of flavonoid co-amorphous systems through combining theory-model-experiment techniques.

All-Small-Molecule Supramolecular Hydrogel Combining Self-Delivery and ROS-Responsive Release for Inhibiting Tumor Growth and Postoperative Recurrence

Supramolecular hydrogels show unprecedented advantages and have attracted widespread attention in biomedical sciences. However, it is challenging for bioactive star molecules, such as celastrol, to meet ideal formation conditions. Here, we report a dynamic covalent method to construct a dihydrol-type celastrol-phenylenediboronic acid-guanosine (DHcelPBG) supramolecular hydrogel. The DHcelPBG hydrogel can effectively accelerate 4T1 cell apoptosis by modulating the PI3K/Akt signaling pathway. Especially, the DHcelPBG hydrogel can serve as a self-delivery platform for reactive oxygen species (ROS)-facilitated self-release. An excessive ROS-containing tumor microenvironment can promote the obtained DHcelPBG hydrogel to kill more 4T1 tumor cells. Meanwhile, the hydrogel also exhibits distinguished degradability and biocompatibility. Subsequently, the orthotopic 4T1 tumor model results further demonstrate that the DHcelPBG hydrogel remarkably inhibits tumor growth and does not damage healthy tissue. In the postoperative recurrence 4T1 tumor model, the DHcelPBG hydrogel also effectively prevents postoperative tumor recurrence and lung metastasis without causing adverse side effects, resulting in an extended lifetime. The DHcelPBG hydrogel also exhibits distinguished degradability and biocompatibility. The DHcelPBG hydrogel integrates ROS-responsiveness, localized self-delivery, and antitumor activity into one system for breast cancer treatment with fewer side effects, showing great potential for clinical transformation in cancer therapy.

Deprotonation-Constructed Instant Gelation Coating for Staphylococcus Disinfection and Preservation of Fresh Food in Multiple Scenarios

The ancient proverb "disease enters through the mouth" elucidates the connection between food and pathogens, underscoring the pivotal role of food preservation in preventing foodborne diseases. Drawing inspiration from ancient food preservation techniques such as waxing and the use of spices, a novel approach combining the deprotonation-induced solid-liquid phase separation of natural polymer solutions with the solubilization of plant-derived antibacterial compounds has been developed. The "two-step soaking" construction strategy enables the creation of biodegradable and adaptable for hydrogel coatings with micro-scale thickness. These multifunctional coatings can be applied to the surfaces of fresh fruits, vegetables, and meats in 35 s, providing both moisture retention and antioxidant protection. The coating's versatility allows for the targeted can achieve the elimination of various Staphylococcus and other bacterial strains through the selection of bactericides with differing antibacterial mechanisms. The scalability of this approach offers significant potential for broad applications in sterilization and food preservation in across diverse contexts.

An ATP-activated spatiotemporally controlled hydrogel prodrug system for treating multidrug-resistant bacteria-infected pressure ulcers

Adenosine triphosphate (ATP)-activated prodrug approaches demonstrate potential in antibacterial uses. However, their efficacy frequently faces obstacles due to uncontrolled premature activation and spatiotemporal distribution differences under physiological circumstances. Herein, we present an endogenous ATP-activated prodrug system (termed ISD3) consisting of nanoparticles (indole-3-acetic acid/zeolitic imidazolate framework-8@polydopamine@platinum, IZPP) embedded in a silk fibroin-based hydrogel, aimed at treating multidrug-resistant (MDR) bacteria-infected pressure ulcers. Initially, an ultraviolet-triggered adhesive ISD3 barrier is formed over the pressure ulcer wound by a simple local injection. Subsequently, the bacteria-secreted ATP prompts the degradation of IZPP, allowing the loaded IAA prodrug and nanozyme to encounter spatiotemporally on a single carrier, thereby efficiently generating reactive oxygen species (ROS). Exposure to 808 nm near-infrared light enhances the catalytic reaction speed, boosting ROS levels for stronger antibacterial action. Once optimal antibacterial action is reached, ISD3 switches to a dormant state, halting any further ROS production. Moreover, the bioactive components in ISD3 can exert anti-inflammatory functions, aiding in pressure ulcer recovery. Overall, our research introduces a hydrogel prodrug strategy activated by bacterial endogenous ATP, which precisely manages ROS generation and accelerates the recovery of MDR bacteria-infected pressure ulcers.

Hydrogel-Based Scaffolds: Advancing Bone Regeneration Through Tissue Engineering

Bone tissue engineering has emerged as a promising approach to addressing the limitations of traditional bone grafts for repairing bone defects. This regenerative medicine strategy leverages biomaterials, growth factors, and cells to create a favorable environment for bone regeneration, mimicking the body's natural healing process. Among the various biomaterials explored, hydrogels (HGs), a class of three-dimensional, hydrophilic polymer networks, have gained significant attention as scaffolds for bone tissue engineering. Thus, this review aimed to investigate the potential of natural and synthetic HGs, and the molecules used for its functionalization, for enhanced bone tissue engineering applications. HGs offer several advantages such as scaffolds, including biocompatibility, biodegradability, tunable mechanical properties, and the ability to encapsulate and deliver bioactive molecules. These properties make them ideal candidates for supporting cell attachment, proliferation, and differentiation, ultimately guiding the formation of new bone tissue. The design and optimization of HG-based scaffolds involve adapting their composition, structure, and mechanical properties to meet the specific requirements of bone regeneration. Current research focuses on incorporating bioactive molecules, such as growth factors and cytokines, into HG scaffolds to further enhance their osteoinductive and osteoconductive properties. Additionally, strategies to improve the mechanical strength and degradation kinetics of HGs are being explored to ensure long-term stability and support for new bone formation. The development of advanced HG-based scaffolds holds great potential for revolutionizing bone tissue engineering and providing effective treatment options for patients with bone defects.

Crosstalk-Assisted Augmented Activity of Polyphenolic Molecules: A Study Using Fluorescence Lifetime Imaging Microscopy

Self-assembly of small molecules has always been an attractive topic of research in the field of physical chemistry. Fluorescence lifetime imaging microscopy (FLIM) expands our understanding by offering a molecular-level perspective to gain deeper knowledge about the microenvironments. In this work, we have unveiled the self-aggregation mechanism of two naturally occurring polyphenolic molecules named gallic acid (GA) and its derivative methyl gallate (MG), resulting in ineffectiveness as a drug molecule. GA prefers rod-like morphology, in contrast to MG, which shows a cotton-like structure. However, when both are present in an equimolar ratio, the cross-assembly manifests a fibrillar structure that loses its initial individualities. Using FLIM, we have unveiled the mechanism of structural transition and morphological information on the aggregated assemblies. Although the parental polyphenols construct significantly rigid morphologies, the cross-assembly manifests improper packing due to mismatch in their backbone, as evident from lifetime information using FLIM. Furthermore, under physiological conditions, the cross-assembly disintegrates; however, the parental molecules prevail their architectures. The co-polyphenols show prominent dose-dependent cytotoxicity and mitigate the progression of cancer cells compared to the individual polyphenols, opening up a convenient way to enhance a drug's efficacy.

Chinese herbal medicine-inspired construction of multi-component hydrogels with antibacterial and wound-healing-promoting functions

Chinese herbal medicine (CHM) has offered a great treasure and source of inspiration for developing innovative medicinal materials and therapy. In this work, inspired by the macroscopic compatibility of Puerariae Lobatae Radix and Gypsum Ustum in CHM, the puerarin (PUE) and CaSO4 (Ca) as the main constituents, respectively, from the two herbs are co-assembled into two-component molecular hydrogels. Such two-component gels exhibited enhanced mechanical properties compared with the single-component PUE gel due to the introduction of crosslinking hydrogen bonds between PUE and Ca. Importantly, the two-component gels show good biocompatibility and antibacterial and antioxidant properties. Moreover, in vivo wound healing experiments on an E. coli-infected mouse model together with the histological and immunological analyses were conducted, revealing that the two-component gels possessed good wound-healing-promoting functions. Our research shows how the medication practice of CHM can contribute to the development of novel bio-soft materials. It is anticipated that more herbal medicine-inspired medicinal materials will be built and tailored for specific bio-applications.

How Advanced are Self-Assembled Nanomaterials for Targeted Drug Delivery? A Comprehensive Review of the Literature

The development of effective drug delivery systems is a key focus in pharmaceutical research, aiming to enhance therapeutic efficacy while minimizing adverse effects. Self-assembled nanostructures present a promising solution due to their tunable properties, biocompatibility, and ability to encapsulate and deliver therapeutic agents to specific targets. This review examines recent advancements in drug-based self-assembled nanostructures for targeted delivery applications, including drug-drug conjugates, polymeric-based architectures, biomolecules, peptides, DNA, squalene conjugates and amphiphilic drugs. Various strategies for fabricating these nanostructures are discussed, with an emphasis on the design principles and mechanisms underlying their self-assembly and potential for targeted drug delivery to specific tissues or cells. Furthermore, the integration of targeting ligands, stimuli-responsive moieties and imaging agents into these nanostructures is explored for enhanced therapeutic outcomes and real-time monitoring. Challenges such as stability, scalability and regulatory hurdles in translating these nanostructures from bench to bedside are also addressed. Drug-based self-assembled nanostructures represent a promising platform for developing next-generation targeted drug delivery systems with improved therapeutic efficacy and reduced side effects.

Carrier-free nanoparticles-new strategy of improving druggability of natural products

There are abundant natural products resources and extensive clinical use experience in China. However, the active components of natural products generally have problems such as poor water solubility and low bioavailability, which limit their druggability. Carrier-free nanoparticles, such as nanocrystals, self-assembled nanoparticles, and extracellular vesicles derived from both animal and plant sources, have great application potential in improving the safety and efficacy of drugs due to their simple and flexible preparation methods, high drug loading capacity and delivery efficiency, as well as long half-life in blood circulation. It has been widely used in biomedical fields such as anti-tumor, anti-bacterial, anti-inflammatory and anti-oxidation. Therefore, based on the natural products that have been used in clinic, this review focuses on the advantages of carrier-free nanoparticles in delivering active compounds, in order to improve the delivery process of natural products in vivo and improve their draggability.

Formation of self-assembly aggregates in traditional Chinese medicine decoctions and their application in cancer treatments

Traditional Chinese Medicine (TCM) formulas, based on the principles of Chinese medicine, have a long history and are widely applied in the treatment of diseases. Compared to single-component drugs, TCM formulas demonstrate superior therapeutic efficacy and fewer side effects owing to their synergistic effects and mechanisms of detoxification and efficacy enhancement. However, various drawbacks, such as the uncertainty of functional targets and molecular mechanisms, poor solubility of components, and low bioavailability, have limited the global promotion and application of TCM formulas. To overcome these limitations, self-assembled aggregate (SA) nanotechnology has emerged as a promising solution. SA nanotechnology significantly enhances the bioavailability and anti-tumor efficacy of TCM by improving its absorption, distribution, and precise targeting capabilities, thereby providing an innovative solution for the modernization and internationalization of TCM. This review delves into the nature and common interactions of SAs based on the latest research developments. The structural characteristics of SAs in TCM formulas, paired-herb decoctions, and single-herb decoctions are analyzed and their self-assembly mechanisms are systematically elucidated. In addition, this article elaborates on the advantages of SAs in cancer treatment, particularly in enhancing the bioavailability and targeting capabilities. Furthermore, this review aims to provide new perspectives for the study of TCM compatibility and its clinical applications, thereby driving the innovative development of nanomaterials in this field. On addressing the technological challenges, SAs are expected to further promote the global application and recognition of TCM in the healthcare sector.

Natural drug delivery systems for the treatment of neurodegenerative diseases

Today, herbal drugs are prominent in the pharmaceutical industry due to their well-known therapeutic and side effects. Plant-based compounds often face limitations such as poor solubility, low bioavailability, and instability in physiological environments, restricting their therapeutic efficacy and delivery. Nanotechnology-based solutions, including nanoparticle formulations and advanced delivery systems like liposomes and transfersomes, address these issues by enhancing solubility, stability, bioavailability, and targeted delivery, thereby optimizing the therapeutic potential of phytoactive compounds. Neuroinflammation can be a cause of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases, or amyotrophic lateral sclerosis. Consequently, there is a need for the optimal delivery of a pharmacological anti-inflammatory agents to the CNS. Thus, the non-invasive administration of a stable compound at a therapeutic concentration is needed to assure molecule crossing through the blood-brain barrier. Natural resources have more structural diversity and novelty than synthetic compounds, e.g. plant-derived drug products have higher molecular weights, incorporate more oxygen atoms, and are more complex. As a result, plant-derived products have unique features which can be used to effectively modulate neuroinflammation. Therefore, this review aims to identify herbal molecules capable of targeting neuroinflammation and present novel strategies for their efficient delivery.

Ordered Assembly of Natural Phenolic Building Blocks for Supramolecular Crystalline Materials

Biomacromolecules such as DNA, proteins, and lipids in nature are constructed by 'bottom-up' assembly with diverse functions and structural ordered characteristics. Supramolecular assemblies have been employed to mimic the natural complexity by manipulating the subtle variations of functional groups. Nevertheless, the intricate design of the driving forces or sophisticated synthesis of molecular skeletons poses challenges in fabricating highly ordered assemblies. Natural phenolic molecules with anisotropic functional groups exhibit potential as versatile building blocks for a wide range of supramolecular crystalline materials with tailored assembly and controlled functionalities. The inherent and anisotropic phenolic groups engage in ordered assembly with various materials via directional covalent bonds (e. g., condensation and coordination) as well as multiple molecular interactions (e. g., hydrogen bonding and π-π interactions), leading to the formation of supramolecular crystalline materials with diverse functionalities. This Concept presents the assembly mechanisms of crystalline phenolic materials and their applications, showcasing the effective utilization of ordered assembly by natural phenolic building blocks.

A novel supramolecular nanodrugs for improving the cognitive function of schizophrenia by protecting active lactone of arecoline

Over 30 % of patients with schizophrenia experience treatment resistance and severe side effects. The limited efficacy of antipsychotic therapies poses a challenge, partly due to the blood-brain barrier (BBB) and the non-selective targeting of these drugs. Herein, we report on arecoline (ARE), a water soluble natural small molecule, which was successfully constructed a phospholipid complex by noncovalent interactions. Most striking, this arecoline-phospholipid complex nanoplatforms (ARE-PC NPs) could prevent the hydrolyzation of its ester group by carboxylesterases, which showed sustained release, superior physiological stability and long circulatory capability. Both in vitro cells and in vivo mice speculated that this ARE-PC NPs might has a high cellular uptake and stronger penetration ability of the BBB. Additionally, our results demonstrated that this phospholipid complex might facilitate ARE delivery to the brain tissue and obviously improve the schizophrenia-like behavior in cuprizone induced animal models. This study highlights ARE-PC NPs as a promising antipsychotic nanodrug for the therapy of schizophrenia.

Amphiphilic Gelator-Based Shear-Thinning Hydrogel for Minimally Invasive Delivery via Endoscopy Catheter to Remove Gastrointestinal Polyps

Injectable polymeric hydrogels delivered via endoscopic catheter have emerged as promising submucosal agents, offering durable, long-lasting cushions to enhance the efficacy of endoscopic submucosal dissection (ESD) for the removal of small, flat polyps from the gastrointestinal tract (GIT). However, polymer-based injections do not meet the easy-injectability criteria via catheter because their high viscosity tends to clog the catheter needle. To the best of knowledge, for the first time, report the fabrication of an amphiphile-based small molecule hydrogel of diglycerol monostearate (DGMS) that self-assembles to form hydrogel (DGMSH) for delivery via an endoscopic catheter. Physicochemical characterization of the hydrogel reveals its fibrous morphology, shear-thinning behaviour, and easy injectability, along with its scalability and long shelf-life (6 months). Ex vivo studies on the goat's stomach and intestine demonstrate the ease of injectability through the catheters and the development of visible submucosal cushion depots with the desired height. Moreover, the hydrogel can encapsulate both hydrophobic and hydrophilic drugs/dyes. In vivo studies in small animals have found that the hydrogel depot is durable, biocompatible, non-immunogenic, and has a hemostatic effect. Endoscopic studies in the porcine model demonstrate a safe injection and endoscopic excision of GI polyps acting as a suitable agent for ESD.

Adhesive and antibacterial guar gum-based nanocomposite hydrogel for remodeling wound healing microenvironment

Hydrogels are promising wound dressings due to their extracellular matrix-like properties and tunable structure-function characteristics. Besides the physical isolation effect, hydrogel dressings are highly expected to possess tissue-adhesive performance and antibacterial capacity, which are beneficial for their clinical translations. Herein, a guar gum (GG)-based nanocomposite hydrogel was fabricated by mixing methacrylated GG (GGMA), acrylic acid, acrylated 3-aminophenylboronic acid, mangiferin (MF)-loaded cetyltrimethyl ammonium chloride (CTAC) micelles (MF@CTAC) and radical initiator. This hydrogel exhibited stable and tunable mechanical property as well as excellent biocompatibility. Borate crosslinking and physical interactions of the hydrogel produced a certain degree of self-healing ability, good tissue adhesive and hemostatic capacity. MF endowed the hydrogel with good antioxidant ability and excellent synergistic antibacterial ability with CATC. In vivo experiments indicated that the hydrogel significantly accelerated wound healing with a narrower wound edge, thicker granulation tissue, maturer epidermis and dermis tissue, higher collagen deposition level, milder inflammatory response, and enhanced angiogenesis. The hydrogel without adding antibiotics and other exogenous active ingredients showed great application potential as a versatile wound dressing material.

Two-Component Hydrogels Built from Chinese Herbal Medicine-Derived Glycyrrhizic Acid and Puerarin: Assembly Mechanism, Self-Healing Properties, and Selective Antibacterial Activity

Chinese herbal medicine has offered a great treasure for discovering intrinsically bioactive low molecular weight gelators (LMWGs). Herein, the two-component hydrogels comprising glycyrrhizic acid (GA) and puerarin (PUE), the primary bioactive components, respectively, from herbs Glycyrrhiza uralensis Fisch and Pueraria lobata are successfully prepared. Combined spectroscopic characterizations reveal that hydrogen bonds are formed between GA and PUE molecules, which further drives the growth of nanofiber assemblies into gel networks. Importantly, micromorphological observation by scanning electron microscopy (SEM), synchrotron small-angle X-ray scattering (SAXS), and molecular dynamic simulation suggest that a coassembly pathway is involved in the gelling process. Such two-component hydrogels exhibit good injectable, self-healing, and adhesive properties. Interestingly, the mixed GA-PUE hydrogels demonstrate a more efficient and selective antibacterial activity toward S. aureus instead of E. coli, and a PUE ratio-dependent antibacterial activity toward S. aureus is also observed. Our work highlights that CHM-derived LMWGs can provide a scaffold for developing multicomponent hydrogels, which may afford novel and distinct properties compared with their individual ones. It is assumed that more multicomponent supramolecular hydrogels derived from CHM would appear to better address the challenges, particularly in the biomedical field.

Chiral helix amplification and enhanced bioadhesion of two-component low molecular weight hydrogels regulated by OH to eradicate MRSA biofilms

The supramolecular chemistry of small chiral molecules has attracted widespread attention owing to their similarity to natural assembly codes. Two-component low-molecular-weight (LMW) hydrogels are crucial as they form helical structures via chirality transfer, enabling diverse functions. Herein, we report a pair of two-component chiral LMW hydrogels based on the small molecular drugs baicalin (BA), scutellarin (SCU) and berberine (BBR). The two hydrogels exhibited different helicities and abilities to adhere to methicillin-resistant staphylococcus aureus (MRSA) biofilms. The BA or SCU can each laterally interact with BBR in a tail-to-tail configuration, forming a stable hydrophobic structure, while hydrophilic glucuronide groups are exposed to a water solution to form a hydrogel. However, the tiny variant steric hindrance of the terminal OH moiety of SCU affects π-π stacking in the layered assembly, resulting in SCU-BBR having much stronger chirality deviation and supramolecular chirality amplification than BA-BBR. Thereafter, the OH group in SCU-BBR forms more intermolecular hydrogen bonds with MRSA biofilms, enhancing stronger adhesion and better scavenging effects than BA-BBR. This work provides a unique chiral supramolecular assembly pattern, expands the antibacterial application prospect of a two-component LMW hydrogel accompanying chirality amplification, and provides a new perspective and strategy for biofilm removal.

Albumin as an Effective Auxiliary Agent for the Enriched Extraction of Anthraquinones and Curcumin from Plant Matrices

Nowadays, several processes to enrich desired bioactive compounds in plant extracts have been developed. The objective of the present study was to assess the performance of bovine serum albumin in increasing the extractive yields of anthraquinones and diarylheptanoids from their respective raw plant powder extracts. Aloe emodin, rhein, emodin, and chrysophanol, from Polygonum cuspidatum, Senna alexandrina, Rhamnus frangula, and Rheum palmatum, and curcumin from Curcuma longa were analyzed in parent dry extracts, solubilized either with water, ethanol, or hydro-alcoholic mixtures, and in ones treated with aqueous solutions of bovine serum albumin by HPLC with UV/Vis detection. The different ratios between the volumes of solvents, powdered plant extracts, and bovine serum albumin were tested. The addition of albumin provided an increase in the yields of aloe emodin in the range 7.8-50.4-fold; of rhein in the range 6.1-14.1-fold; of emodin in the range 19.7-39.7-fold; of chrysophanol in the range 15.1-28.7-fold; and, finally, of curcumin of 32.1-fold. The addition of bovine serum albumin in the processing of plant extracts has been shown to be a novel and a valid alternative, comparing favourably to already reported methodologies. The easy-to-handle procedures, readily accessible facilities, and the employment of cheap substrates and reagents represent the most evident advantages of the methodology described herein.

Photo-controlled multifunctional hydrogel for photothermal sterilization and microenvironment amelioration of infected diabetic wounds

Diabetic foot ulcers are linked to a high disability rate, with no effective treatment currently available. Addressing infection, reducing oxidative stress, and safely managing chronic inflammation remain major challenges. In this study, a composite hydrogel dressing was developed using natural substances or clinically approved components (dopamine, D-alpha-tocopheryl polyethylene glycol succinate, and rhein). Upon near-infrared laser irradiation, the composite system rapidly heats and solidifies into a gel with photothermal antibacterial properties. Additionally, the decomposition of hydrogen peroxide releases oxygen, alleviating wound hypoxia. The hydrogel exhibited strong bactericidal activity against multiple bacterial strains. Without laser irradiation, the hydrogel effectively scavenged various free radicals and intracellular reactive oxygen species, restoring redox balance. Furthermore, it significantly reduced the expression of inflammatory cytokines, including interleukin-6 and interleukin-1β. In a diabetic mouse wound model infected with S. aureus, the mild photothermal therapy, combined with the antibacterial action of rhein, effectively managed bacterial infections, reduced inflammation, and promoted wound healing. Consequently, the photo-controlled therapeutic approach, offering antibacterial, antioxidant, and anti-inflammatory effects, holds promise for the effective treatment and management of infected diabetic wounds.

Intrinsic immunomodulatory hydrogels for chronic inflammation

The immune system plays a pivotal role in maintaining physiological homeostasis and influencing disease processes. Dysregulated immune responses drive chronic inflammation, which in turn results in a range of diseases that are among the leading causes of death globally. Traditional immune interventions, which aim to regulate either insufficient or excessive inflammation, frequently entail lifelong comorbidities and the risk of severe side effects. In this context, intrinsic immunomodulatory hydrogels, designed to precisely control the local immune microenvironment, have recently attracted increasing attention. In particular, these advanced hydrogels not only function as delivery mechanisms but also actively engage in immune modulation, optimizing interactions with the immune system for enhanced tissue repair, thereby providing a sophisticated strategy for managing chronic inflammation. In this tutorial review, we outline key elements of chronic inflammation and subsequently explore the strategic design principles of intrinsic immunomodulatory hydrogels based on these elements. Finally, we examine the challenges and prospects of such immunomodulatory hydrogels, which are expected to inspire further preclinical research and clinical translation in addressing chronic inflammation.

Imatinib@glycymicelles entrapped in hydrogel: preparation, characterization, and therapeutic effect on corneal alkali burn in mice

Imatinib (IMB) is a type of tyrosine kinase inhibitor with great application potential for inhibiting corneal neovascularization (CNV), but its poor water solubility limits its application in eye disease treatment. In this study, novel IMB@glycymicelles entrapped in hydrogel (called IMB@glycymicelle-hydrogel) were prepared, characterized, and evaluated for their therapeutic effects on corneal alkali burn in mice. Imatinib could be successfully loaded in glycymicelles using glycyrrhizin as a nanocarrier with an optimized weight ratio of IMB:nanocarrier. The apparent solubility of IMB was significantly improved from 61.69 ± 5.55 μg/mL to bare IMB to 359,967.62 ± 20,059.42 μg/mL to IMB@glycymicelles. Then, the IMB@glycymicelles were entrapped in hydrogel fabricated with hydroxypropyl methylcellulose and sodium hyaluronate (HA) to prolong retention time on the ocular surface. Rabbit eye tolerance tests showed that IMB@glycymicelle-hydrogel possessed good ocular safety profiles. In a mouse model of corneal alkali burns, the topical administration of IMB@glycymicelle-hydrogel showed strong efficacy by prompting corneal wound healing, recovering corneal sensitivity, relieving corneal opacities, and inhibiting CNV, and these efficacy evaluation parameters were better than those of the positive drug HA. Overall, these results demonstrated that IMB@glycymicelle-hydrogel may be a promising candidate for the effective treatment of alkali ocular damage.

Simple Preparation and Bone Regeneration Effects of Poly(vinyl alcohol)-Resveratrol Self-Cross-Linked Hydrogels

Hydrogels have broad application prospects in bone repair. Pure poly(vinyl alcohol) (PVA) hydrogels have limited applications because of their low hardness and poor mechanical properties. This study found that resveratrol (Res) and PVA self-assembled and cross-linked through the formation of strong hydrogen bonds after freeze-thawing, forming an easily available PVA-Res supramolecular hydrogel through a green process. PVA-Res hydrogels with different Res wt %:10 wt % PVA ratios were prepared through freeze-thawing and designated as 0.4, 1.2, and 2.0 wt % PVA-Res hydrogels. Rheological studies demonstrated that the viscoelastic modulus of the PVA-Res hydrogels was significantly improved compared to pure PVA hydrogels. The viscoelastic modulus G' of 1.2% PVA-Res hydrogel was 2299 Pa, which was 8.5-fold that of the pure PVA hydrogel. We conducted a study on cell proliferation and osteogenic differentiation using MC3T3-E1 (preosteoblasts from newborn mouse calvaria). The results showed that the 0.4% PVA-Res hydrogel promotes alkaline phosphatase activity and mineral deposition. Real-time quantitative PCR (RT-qPCR) analysis demonstrated that the 0.4% PVA-Res hydrogel upregulated the expression of osteogenic differentiation-related genes (BMP-9, OCN, and ALP). Furthermore, RT-qPCR and flow cytometry demonstrated that the 0.4% PVA-Res hydrogel could effectively promote the M2 transformation and polarization of mouse mononuclear macrophage leukemia cells (Raw 264.7). The expression of related genes, such as Arg-1 and CD206, significantly increased, whereas that of M1 polarization-related genes, such as iNOS and TNF-α, significantly decreased. In summary, PVA-Res supramolecular hydrogels are potential materials for use in bone repair.

Chaihu-Shugan-San Ameliorated Osteoporosis of Mice with Depressive Behavior Caused by Chronic Unpredictable Mild Stress via Repressing Neuroinflammation and HPA Activity

Objective

Depression and osteoporosis are usually concurrent health problems. This study aimed to explore the development of osteoporosis in depressive mice model and investigate the beneficial effects of the classical herbal formula Chaihu-Shugan-San (CHSG) on the brain and bone.

Methods

CHSG powder was prepared by spray-drying following extraction with water. The fingerprint of CHSG was analyzed using liquid chromatography. The depressive-like model was established by chronic unpredictable mild stress (CUMS) in female mice. The depressive behaviors and trabecular bone properties (measured by micro-CT) were detected at 2, 4, 6, and 8 weeks of CUMS. RT-PCR, immunoblotting and immunofluorescence were applied to measure expression of inflammatory cytokines and morphology of microglias in the hippocampus. Biochemical measurements and histological staining on the adrenal gland were carried out to assess the activity of hypothalamic-pituitary-adrenal (HPA) axis. Histological staining, three-point bending strength, and the expression of regulators involved in bone metabolism were determined.

Results

The treatment with CHSG for 8 weeks could ameliorate depressive behaviors, and down-regulate mRNA expression and tissue content of inflammatory factors IL-1β and IL-6 in hippocampus of CUMS mice. The inhibition of CHSG on neuroinflammation might be attributed to its repression of activity in microglias and NLRP3-triggered inflammation pathway. The serum of rats dramatically alleviated LPS-induced phosphorylation of nuclear NFκB (P65) and IκBα and up-regulation of IL-1β and IL-6 proteins in microglia BV2 cells. CUMS induced over-activity of HPA axis shown by the elevation in serum level of ACTH and corticosterone and in area percentage of zona fasciculata, intriguingly, CHSG reversed those changes in HPA system, ameliorated the reduction in mechanical strength and bone mineral density, and regulated bone metabolism factors of CUMS mice.

Conclusion

The chronic stress-induced depression resulted in bone disorders developing to osteoporosis. Chaihu-Shugan-San exerted beneficial effects on skeletal tissue by ameliorating neuroinflammation and HPA over-activity of mice with depression.

Self-assembled carrier-free formulations based on medicinal and food active ingredients

The popularity of medicinal plants, which have a unique system and are mostly used in compound form for the prevention and treatment of a wide range of diseases, is growing worldwide. In recent years, with advances in chemical separation and structural analysis techniques, many of the major bioactive molecules of medicinal plants have been identified. However, the active ingredients in medicinal plants often possess chemical characteristics, including poor water solubility, stability and bioavailability, which limit their therapeutic applications. To address this problem, self-assembly of small molecules from medicinal food sources provides a new strategy. Driven by various types of acting forces, medicinal small molecules with modifiable groups, multiple sites of action, hydrophobic side chains, and rigid backbones with self-assembly properties are able to form various supramolecular network hydrogels, nanoparticles, micelles, and other self-assemblies. This review first summarizes the forms of self-assemblies such as supramolecular network hydrogels, nanoparticles, and micelles at the level of the action site, and discusses the recent studies on the active ingredients in medicinal plants that can be used for self-assembly, in addition to summarizing the advantages of self-assemblies for a variety of disease applications, including wound healing, antitumor, anticancer, and diabetes mellitus. Finally, the problems of self-assemblers and the possible directions for future development are presented. We firmly believe that self-assemblers have the potential to develop effective compounds from drug-food homologous plants, providing valuable information for drug research and new strategies and perspectives for the modernization of Chinese medicine.

Recent advances in carrier-free natural small molecule self-assembly for drug delivery

Natural small-molecule drugs have been used for thousands of years for the prevention and treatment of human diseases. Most of the natural products available on the market have been modified into various polymer materials for improving the solubility, stability, and targeted delivery of drugs. However, these nanomedicines formed based on polymer carriers would produce severe problems such as systemic toxicity and kidney metabolic stress. In contrast, the carrier-free nanomedicines formed by their self-assembly in water have inherent advantages such as low toxicity, good biocompatibility, and biodegradability. This review summarizes the assembly process and application of natural small-molecule products, which are mainly driven by multiple non-covalent interactions, and includes single-molecule assembly, bimolecular assembly, drug-modified assembly, and organogels. Meanwhile, the molecular mechanism involved in different self-assembly processes is also discussed. Self-assembly simulation and structural modification of natural small-molecule products or traditional Chinese medicine molecules using molecular dynamics simulation and computer-assisted methods are proposed, which will lead to the discovery of more carrier-free nanomedicine drug delivery systems. Overall, this review provides an important understanding and strategy to study single-molecule and multi-molecule carrier-free nanomedicines.

Active herbal ingredients and drug delivery design for tumor therapy: a review

Active herbal ingredients are gaining recognition for their potent anti-tumor efficacy, attributable to various mechanisms including tumor cell inhibition, immune system activation, and tumor angiogenesis inhibition. Recent studies have revealed that numerous anti-tumor herbal ingredients, such as ginsenosides, ursolic acid, oleanolic acid, and Angelica sinensis polysaccharides, can be utilized to develop smart drug carriers like liposomes, micelles, and nanoparticles. These carriers can deliver active herbal ingredients and co-deliver anti-tumor drugs to enhance drug accumulation at tumor sites, thereby improving anti-tumor efficacy. This study provides a comprehensive analysis of the mechanisms by which these active herbal ingredients-derived carriers enhance therapeutic outcomes. Additionally, it highlights the structural properties of these active herbal ingredients, demonstrating how their unique features can be strategically employed to design smart drug carriers with improved anti-tumor efficacy. The insights presented aim to serve as a reference and guide future innovations in the design and application of smart drug carriers for cancer therapy that leverage active herbal ingredients.

Revealing the scientific connotation of compatibility of Chinese medicine medica based on self-assembly technology

Chinese materia medica (CMM) compatibility is one core content in the theory of Traditional Chinese Medicine (TCM), and elaborating the scientific connotation of CMM compatibility is of great significance to promote the modernization of TCM. Self-assembly is the combination of active ingredients into aggregates through non-covalent bonds, such as hydrogen bonding, electrostatic interactions, ionic interactions, and hydrophobic interactions. The complex properties and special structures of CMM components create the basis for self-assembly. The self-assembled materials formed after CMM compatibility is an important part of the material basis for the efficacy of TCM, which can help explain the scientific connotations of CMM compatibility. This review summarizes the self-assembly phenomenon from the perspective of drug pair combinations in recent decades and explains the scientific connotation of CMM compatibility about the material basis, pharmacodynamic changes, and mechanism of action, providing new ideas and methods for the study of TCM.

Natural polysaccharide hydrogel with bioadhesion characters to synergistically enhance berberine's antibacterial effect by regulating the PTS system of Staphylococcus aureus

The global spread of Staphylococcus aureus (S. aureus) not only causes significant economic losses but also poses a serious threat to public health. Consequently, there is an urgent need for multidimensional strategies to develop antimicrobial dressings to combat bacterial infections. In response, we have developed a plant polysaccharide antibacterial hydrogel formed through the self-assembly of edible Kudzu powder (KP) and the natural star molecule berberine (BBR). Rheological tests show that natural polysaccharide KP-BBR hydrogel (BBR@KP) exhibits excellent injectability and adhesion. And the degradation of the hydrogel exceeded 90 % within 3 days. The synergistic effect of these two ingredients enhances the antibacterial activity of BBR and can increase the MIC of BBR to 0.05 mM. Specifically, KP promotes the affinity of the Phosphoenolpyruvate Phosphotransferase System (PTS) of S. aureus, enabling KP, with its bioadhesive properties, to adhere to the bacterial surface and continuously release BBR. Subsequently, BBR effectively exerts its antibacterial effect by inhibiting the synthesis of histidine and isoleucine. Furthermore, the BBR@KP hydrogel exhibits negligible cytotoxicity and hemolytic toxicity, underscoring its favorable biosafety profile. This synergistic natural antibacterial hydrogel, formulated through a green and straightforward methodology, not only holds promise for broad clinical applications but also provides novel perspectives for the utilization and development of plant polysaccharides in the biomedical field.

Counter-intuitive discovery in the formulation of poorly water-soluble drugs: Amorphous small-molecule gels

Amorphous strategies have been extensively used in improving the dissolution of insoluble drugs for decades due to their high free energy. However, the formation of amorphous small-molecule gels (ASMGs) presents a counter-intuitive discovery that significantly limits their practical application. Recently, ASMGs have garnered attention because of their noncovalent structures, excellent biodegradability, and significant potential in various drug delivery systems in the pharmaceutical field. Hence, a comprehensive review is necessary to contribute to a better understanding of recent advances in ASMGs. This review aimed to introduce the main formation mechanisms, summarize possible influencing factors, generalize unique properties, outline elimination strategies, and discuss clinical application potential with preclinical cases of ASMGs. Moreover, few ASMGs are advanced to clinical stages. Intensive clinical research is needed for further development. We hope that this review can provide more efficient and rational guidance for exploring further clinical applications of ASMGs.

Small Molecule Hydrogels Loading Small Molecule Drugs from Chinese Medicine for the Enhanced Treatment of Traumatic Brain Injury

Self-assembly of hydrogels for mechanical support and drug delivery has been extensively researched in traumatic brain injury (TBI), where treatment options are limited. The chief challenge is that most self-assembled hydrogels rely on high molecular carriers or the incorporation of exogenous inactive substances as mediators. It is difficult for these drug delivery systems to achieve clinical translation due to concerns regarding biological safety. Here we report a small molecule hydrogel (GBR-gel) loading small molecule drugs (glycyrrhizic acid, berberine, and rhein) that originated from popular Chinese medicines without additional drug loading or inactive components under physiological conditions. In the long run, GBR-gel possesses several advantages, including ease of preparation, cost-effectiveness, and high biocompatibility. As a proof-of-concept, GBR-gel allows for prompt administration at the site of brain injury to exert potent pharmacodynamic effects. Further single-cell RNA sequencing and experimental validation indicated that GBR-gel can effectively rescue the suppressed glutamatergic synapse pathway after TBI, thereby attenuating inflammatory responses and neural impairments. Our work provides an alternative strategy for timely intervention of TBI.

Enzymatically Triggered Drug Release from Microgels Controlled by Glucose Concentration

This study aims to design microgels for controlled drug release via enzymatically generated pH changes in the presence of glucose. Modern medicine is focused on developing smart delivery systems with controlled release capabilities. In response to this demand, we present the synthesis, characterization, and enzymatically triggered drug release behavior of microgels based on poly(acrylic acid) modified with glucose oxidase (GOx) (p(AA-BIS)-GOx). TEM images revealed that the sizes of air-dried p(AA-BIS)-GOx microgels were approximately 130 nm. DLS measurements showed glucose-triggered microgel size changes upon glucose addition, which depended on buffer concentration. Enzymatically triggered drug release experiments using doxorubicin-loaded microgels with immobilized GOx demonstrated that drug release is strongly dependent on glucose and buffer concentration. The highest differences in release triggered by 5 and 25 mM glucose were observed in HEPES buffer at concentrations of 3 and 9 mM. Under these conditions, 80 and 52% of DOX were released with 25 mM glucose, while 47 and 28% of DOX were released with 5 mM glucose. The interstitial glucose concentration in a tumor ranges from ∼15 to 50 mM. Normal fasting blood glucose levels are about 5.5 mM, and postprandial (2 h after a meal) glucose levels should be less than 7.8 mM. The obtained results highlight the microgel's potential for drug delivery using the enhanced permeability and retention (EPR) effect, where drug release is controlled by enzymatically generated pH changes in response to elevated glucose concentrations.

Natural Biological Solutions for Chronic Pathological Problems

Naturally sourced biomolecules and their derivatives have had significant historical impacts in terms of their biomedical application [...].

Enhanced Mechanical Strength and Sustained Drug Release in Carrier-Free Silver-Coordinated Anthraquinone Natural Antibacterial Anti-Inflammatory Hydrogel for Infectious Wound Healing

The persistent challenge of healing infectious wounds and the rise of bacterial resistance represent significant hurdles in contemporary medicine. In this study, based on the natural small molecule drug Rhein self-assembly to form hydrogels and coordinate assembly with silver ions (Ag+), a sustained-release carrier-free hydrogel with compact structure is constructed to promote the repair of bacterial-infected wounds. As a broad-spectrum antimicrobial agent, Ag+ can avoid the problem of bacterial resistance caused by the abuse of traditional antibiotics. In addition, due to the slow-release properties of Rhein hydrogel, continuous effective concentration of Ag+ at the wound site can be ensured. The assembly of Ag+ and Rhein makes the hydrogel system with enhanced mechanical stability. More importantly, it is found that Rhein effectively promotes skin tissue regeneration and wound healing by reprogramming M1 macrophages into M2 macrophages. Further mechanism studies show that Rhein realizes its powerful anti-inflammatory activity through NRF2/HO-1 activation and NF-κB inhibition. Thus, the hydrogel system combines the excellent antibacterial properties of Ag+ with the excellent anti-inflammatory and tissue regeneration ability of Rhein, providing a new strategy for wound management with dual roles.