Oral nanotherapeutics based on Antheraea pernyi silk fibroin for synergistic treatment of ulcerative colitis

Antheraea pernyi silk nanofibrils with inherent RGD motifs accelerate diabetic wound healing: A novel drug-free strategy to promote hemostasis, regulate immunity and improve re-epithelization

The chronic inflammation and matrix metalloprotease (MMP)-induced tissue degradation significantly disrupt re-epithelization and delay the healing process of diabetic wounds. To address these issues, we produced nanofibrils from Antheraea pernyi (Ap) silk fibers via a facile and green treatment of swelling and shearing. The integrin receptors on the cytomembrane could specifically bind to the Ap nanofibrils (ApNFs) due to their inherent Arg-Gly-Asp (RGD) motifs, which activated platelets to accelerate coagulation and promoted fibroblast migration, adhesion and spreading. These degradable nanofibrils served as effective competitive substrates to reduce MMP-induced tissue degradation. ApNFs and their enzymatic hydrolysates could modulate macrophage polarization due to their RGD motifs. RNA sequencing further revealed that ApNFs treatment activated the JAK2-STAT5b and PI3K-Akt signaling pathways while suppressed the NF-κB, IL-17 and TNF signaling pathways in macrophages. The full-thickness skin wound experiments confirmed that ApNFs significantly accelerated wound healing in both diabetic and non-diabetic rats. Notably, in diabetic wound, ApNFs and their enzymatic hydrolysates polarized the accumulated M1-type macrophages into M2-type, which promoted the wound to get rid of the inflammatory stage and transition to the following proliferative stage, improving the wound healing percentage on day 14 from 74.9 % to 93.2 % by facilitating collagen deposition, angiogenesis and re-epithelization. These results demonstrate that ApNFs are promising drug-free diabetic wound dressings with favorable inherent immunoregulatory properties for biomedical translation.

Auranofin loaded silk fibroin nanoparticles for colorectal cancer treatment

Colorectal cancer (CRC) is the second most common cause of cancer related deaths worldwide and the prevalence in young people especially is increasing annually. In the search for innovative approaches to treat the disease, drug delivery systems (DDS) are promising owing to their unique properties, which allow improved therapeutic results with lower drug concentrations, overcoming drug resistance and at the same time potentially reducing side effects. Silk fibroin is a biopolymer that can be processed to obtain biocompatible and biodegradable nanoparticles that can be efficiently loaded by surface adsorption with small-molecule therapeutics and allow their transport and sustained release by modulating their pharmacokinetics. Auranofin (AF) has recently been repurposed for its strong anticancer activity and is currently in clinical trials. Its mechanism of action is through the inhibition of thioredoxin reductase enzymes, which play an essential role in several intracellular processes and are overexpressed in some tumours. Taking into account that AF has a low solubility in water, we propose silk fibroin nanoparticles (SFN) as AF carrier in order to improve its bioavailability, increasing cellular absorption and preventing its degradation or avoiding some resistance mechanisms. Here we report the preparation and characterization of a new formulation of AF-loaded silk fibroin nanoparticles (SFN-AF), its functionalization with FITC for the analysis of cellular uptake, as well as its cytotoxic activity against cell lines of human colorectal cancer (HT29 and HCT116) in both 2D and 3D cell cultures. 3D spheroid models provide a 3D environment which mimics the 3D aspects of CRC observed in vivo and represents an effective 3D environment to screen therapeutics for the treatment of CRC. The loaded nanoparticles showed a spherical morphology with a hydrodynamic diameter of ~ 160 nm and good stability in aqueous solution due to their negative surface charges. FESEM-EDX analysis revealed a homogeneous distribution of Au clusters with high electron density on the surface of the nanoparticles. SFN-AF incubated in phosphate buffer at 37 °C released 77% of the loaded AF over 10 days, showing an initial burst and then sustained release. Flow cytometry analysis showed that FITC-SFN-AF was efficiently internalized by both cell lines, which was confirmed by confocal microscopy imaging. SFN enhanced the cytotoxicity of AF in 2D cultures in both CRC lines. Promising results were also obtained in 3D culture paving the way for future application of this strategy as a therapy for CRC.

Magnetite Micro/Nanorobots for Efficient Targeted Alleviation of Inflammatory Bowel Disease

Millions of people worldwide have inflammatory bowel disease (IBD). Self-driven micro/nanorobots (MNRs) are efficient in the treatment of IBD. However, their lack of controllability regarding direction of motion in the organism and their inability to achieve continuous navigation limits their further application. In this study, polydopamine is wrapped around the magnetite surface, loaded with an anti-inflammatory drug resveratrol, and wrapped with pH-responsive sodium alginate to obtain magnetic MNRs. MNRs can be driven by magnetic fields to achieve directional movement and targeted transportation. In addition, MNRs can effectively remove reactive oxygen species from the inflammation site, repair intestinal damage, inhibit the cellular pathway of pro-inflammatory factors, such as MAPK and NF-κB pathways, and restore intestinal flora, thereby relieving IBDs. MNRs are safe and effective for in vivo treatment of IBD and have proven to be a promising therapeutic platform. This MNRs therapeutic strategy provides new insights into comprehensive IBD therapy.

Lactobacillus acidophilus extracellular vesicles-coated UiO-66-NH2@siRNA nanoparticles for ulcerative colitis targeted gene therapy and gut microbiota modulation

Ulcerative colitis (UC) is a complex and chronic inflammatory bowel disease whose pathogenesis involves genetic and environmental factors, which poses a challenge for treatment. Here, we have designed an innovative integrated therapeutic strategy using Lactobacillus acidophilus extracellular vesicles (EVs) to encapsulate UiO-66-NH2 nanoparticles bounded with TNF-α siRNA (EVs@UiO-66-NH2@siRNA) for UC treatment. This system shows superior affinity to inflammation-related cells due to the Lactobacillus acidophilus EVs can maintain immune homeostasis by regulating the secretion of cytokines in vitro. siRNA can specifically target the key inflammatory TNF-α in UC and silence its gene expression, thereby regulating the process of inflammatory response. After oral administration, EVs@UiO-66-NH2@siRNA demonstrates an accurate delivery of TNF-α siRNA to colonize the colon site and exerts a siRNA therapeutic effect by inhibiting the expression of TNF-α, which alleviates the intestinal inflammation in DSS-induced UC model. Moreover, this system can modulate the types and compositional structures of gut microbiota and metabolites to achieve an anti-inflammatory phenotype, which is helpful for the repair of intestinal homeostasis. We also have proved that UiO-66-NH2 nanoparticles exhibit a high loading capacity for TNF-α siRNA and good pH responsiveness, improving the potent release of siRNA in colon tissue. Collectively, the EVs@UiO-66-NH2@siRNA nano-delivery system demonstrate a feasible combination therapeutic strategy for UC through gut microecology modulation, immune regulation and TNF-α siRNA silence, which may provide a potential targeted treatment approach for inflammatory bowel disease.

Dextran sulfate-coated curcumin nanocrystals for the treatment of DSS-induced ulcerative colitis in mice

Ulcerative colitis is an inflammatory disease that primarily involves intestinal inflammation and epithelial damage. The nano-targeted drug delivery system delivers drugs to the disease site, exerting effects such as inhibiting inflammatory response and reducing reactive oxygen species expression, thereby promoting recovery from ulcerative colitis. In this experiment, dextran sulfate-coated curcumin nanocrystals (NBD) were prepared for the oral treatment of ulcerative colitis (UC). NBD not only significantly enhances the water solubility and stability of curcumin but also possesses the ability of sustained release and targeting inflammatory macrophages. The sustained release effect of NBD was demonstrated by in vitro release experiments. In simulated gastric fluid, the cumulative release amount of NBD at 2 h was 21.99 ± 1.93 %, while in simulated colonic fluid, the cumulative release amount of NBD at 12 h was 84.98 ± 2.02 %. The ability of NBD to target inflammatory macrophages was verified through the transwell system, rat one-way intestinal perfusion experiment and in vivo imaging system. The in vitro and in vivo (mice) anti-inflammatory and antioxidant capacities of NBD were validated using immunofluorescence experiment, ELISA kits and reactive oxygen species-related detection kits. The results indicated that NBD could reduce inflammatory responses, promote macrophage polarization and inhibit oxidative stress. In addition, the therapeutic effect of NBD was further confirmed in this experiment by the clostridium perfringens-induced necrotizing enteritis model in chickens. In conclusion, NBD might be a potential pharmaceutical preparation for the treatment of UC.

Multifunctional applications of silk fibroin in biomedical engineering: A comprehensive review on innovations and impact

Silk fibroin (SF) is a biomaterial naturally produced by certain insects (notably silkworms), animals such as spiders, or through recombinant methods in genetically modified organisms. Its exceptional mechanical properties, biocompatibility, degradability, and bioactivity have inspired extensive research. In biomedicine, SF has been utilized in various forms, including gels, membranes, microspheres, and more. It also demonstrates versatility for applications across medical devices, regenerative medicine, tissue engineering, and related fields. This review explores the current research status, advantages, limitations, and potential application pathways of SF in biomedical engineering. The objective is to stimulate innovative ideas and perspectives for research and applications involving silk.

Inflammatory Microenvironment-Responsive Microsphere Vehicles Modulating Gut Microbiota and Intestinal Inflammation for Intestinal Stem Cell Niche Remodeling in Inflammatory Bowel Disease

Intestinal stem cells (ISCs) engage in proliferation to maintain a stable stem cell population and differentiate into functional epithelial subpopulations. This intricate process is upheld by various signals derived from the host and gut microbiota, establishing an ISC niche. However, during inflammatory bowel disease (IBD), this signaling niche undergoes dramatic changes, leading to impaired ISC and hindered restoration of the damaged intestinal epithelial barrier. This study introduces intestinal inflammatory microenvironment-responsive microsphere vehicles designed to remodel the ISC niche, offering an approach to treat IBD. Using an advanced emulsion technique, these microsphere vehicles specifically target colonic inflammation sites, delivering a responsive release of MXene and l-arginine. This delivery system is formulated to modulate intestinal flora and immune responses effectively. l-arginine is converted into nitric oxide to regulate the gut microbiome, while MXene serves as a nanoimmunomodulator to stabilize immune homeostasis. Our findings demonstrate that the anti-inflammatory properties of the microspheres are key to promoting epithelial repair and remodeling of the ISC niche. This study highlights the role of antioxidant microspheres as anti-inflammatory agents that indirectly support ISC function and gut regeneration.

Silk Fibroin Nanoparticles for Enhanced Cuproptosis and Immunotherapy in Pancreatic Cancer Treatment

Cuproptosis is a newly discovered copper ion-dependent programmed cell death. Elesclomol (ES) is a Cu2+ transporter that delivers Cu2+ into tumor cells, causing cell death at toxic doses. However, ES has a short blood half-life, limiting its accumulation in tumors. This study introduces Tussah silk fibroin nanoparticles (TSF@ES-Cu NPs) to protect ES and Cu2+. TSF, with a stable structure, resists metabolism in circulation. Targeting tumors with natural RGD peptides and TSF's unique secondary structure, enhances drug enrichment and special release in pancreatic tumors, improving treatment efficacy. In vitro, TSF@ES-Cu induces tumor cell cuproptosis, releases DAMPs, promotes dendritic cells (DCs) maturation, and macrophage M1 polarization. In vivo, TSF@ES-Cu reshapes the tumor microenvironment (TME), increasing mature DCs from 22.7% to 43.3%, CD8+ T cells from 5.08% to 17.1%, and reducing M2 macrophages from 50.7% to 18.4%. Additionally, the combined anti-tumor efficacy of TSF@ES-Cu and αPDL-1 is 1.6 times higher than TSF@ES-Cu alone and 2.5 times higher than αPDL-1 alone. In summary, this study reports that the combination of TSF@ES-Cu and αPDL-1 effectively induces cuproptosis and reshapes the TME, offering a new approach for copper nanomaterial-based tumor immunotherapy.

Functional chitosan/HP-β-CD hydrogel for targeted co-delivery of Rhubarb-derived nanovesicles and kaempferol for alleviating ulcerative colitis

Ulcerative colitis (UC) remains a major challenge in clinical treatment due to its multivariate pathology. Developing an oral formulation that encapsulates and delivers multiple active ingredients to target colon tissues by suppressing intestinal inflammation and restoring the intestinal barrier is crucial for effectively treating UC. Here, we developed rhubarb-derived nanovesicles (RNs) and a supramolecular hydrogel platform formed by furfural-functionalized chitosan-mannose polymer and synthesized 3-maleimide HP-β-CD, with kaempferol (Kae) integrated into the hydrophobic cavity. The hydrogel's cross-linking network effectively encapsulates RNs, forming the Kae/CMCHD@RNs system. Rheology, SEM, TGA, degradation behavior, in vitro drug release, and a macrophage-targeted permeability test were performed. The results indicate that the hydrogel utilizes pH/enzyme sensitivity to ensure sustained release in the colon, while also facilitating targeted delivery to macrophages. In vivo imaging further reveals a prolonged local drug retention time in the colon. Moreover, both in vitro and in vivo studies demonstrate RNs and Kae exhibit synergistic therapeutic effects for UC, including inflammation reduction, oxidative stress alleviation, M1-to-M2 macrophage repolarization, and restoration of the intestinal barrier. Consequently, this study underscores the potential of Kae/CMCHD@RNs as a promising therapeutic approach for managing UC.

Tailored strategies based on polysaccharide structural and functional properties for nutrients delivery in inflammatory bowel disease

Many food nutrients suffer from a series of limitations such as poor water solubility, low stability and inadequate bioavailability. These challenges can be effectively improved by food-based delivery systems (FDSs). FDSs are a series of functional carriers developed based on food-borne macromolecules. Natural polysaccharides are widely used in FDSs due to their good bioactivity, functional properties, and biocompatibility. The complex structural and physicochemical properties of polysaccharides have led to the extremely diverse development of FDSs based on polysaccharides. This review summarizes the application of natural polysaccharides from different sources in the development of different types of FDSs and their functional properties. It also emphasizes the feasibility and theoretical strategies to tailor satisfactory properties (shape, size, surface charge and targeting properties) of polysaccharides-based oral delivery systems (PODS) based on the diverse structural characteristics (e.g., solubility, ion type, molecular weight) and bioactivities of polysaccharides. PODS are designed to meet the diverse requirements in term of stability, toxicity, adhesion, cellular uptake, retention time and release behavior. This review also discusses the advantages of PODS in addressing nutrient deficiencies in gastrointestinal environment, with a focus on their role in nutritional interventions for inflammatory bowel disease. This review contributed to the development for novel PODS with specific demand.

Yeast-Inspired Orally-Administered Nanocomposite Scavenges Oxidative Stress and Restores Gut Immune Homeostasis for Inflammatory Bowel Disease Treatment

Excessive oxidative stress, dysregulated immune homeostasis, and disruption of the intestinal epithelial barrier are crucial features of inflammatory bowel disease (IBD). Traditional treatments focusing solely on inflammation resolution remain unsatisfactory. Herein, a yeast-inspired orally administered nanocomposite was developed. First, the MD@MPDA core was fabricated by integrating manganese dioxide (MnO2) nanozymes onto diallyl trisulfide (H2S prodrug)-loaded mesoporous polydopamine nanoparticles (MPDA). Then, yeast cell wall (YCW) was chosen to encapsulate MD@MPDA, namely, YMD@MPDA. The β-glucan embedded in the YCW shell not only protected the nanocomposite from the harsh gastrointestinal environment but also allowed the targeting enrichment in the inflamed colon. Furthermore, M1 macrophages triggered the intracellular GSH-responsive H2S release in the pathological microenvironment. MD@MPDA effectively alleviated inflammatory responses by MnO2-mediated ROS-scavenging and H2S-participated immunomodulation. The synergistic action contributed to macrophage mitochondrial function restoration and M2 polarization by suppressing NOX4 signaling and p38 MAPK pro-inflammatory signaling. In the mice model of dextran sulfate sodium (DSS)-induced IBD, the multipronged manner of scavenging oxidative stress, remodeling innate and adaptive immune homeostasis, and reshaping gut microbiota caused by YMD@MPDA effectively ameliorated inflammation and restored intestinal barrier functions. Overall, the YMD@MPDA nanocomposite provides a promising codelivery strategy of antioxidative nanozymes and gas prodrugs for the comprehensive management of IBD.

Compliant immune response of silk-based biomaterials broadens application in wound treatment

The unique properties of sericin and silk fibroin (SF) favor their widespread application in biopharmaceuticals, particularly in wound treatment and bone repair. The immune response directly influences wound healing cycle, and the extensive immunomodulatory functions of silk-based nanoparticles and hydrogels have attracted wide attention. However, different silk-processing methods may trigger intense immune system resistance after implantation into the body. In this review, we elaborate on the inflammation and immune responses caused by the implantation of sericin and SF and also explore their anti-inflammatory properties and immune regulatory functions. More importantly, we describe the latest research progress in enhancing the immunotherapeutic and anti-inflammatory effects of composite materials prepared from silk from a mechanistic perspective. This review will provide a useful reference for using the correct processes to exploit silk-based biomaterials in different wound treatments.

Protocatechuic acid/sodium alginate multilayer coating induced by metal ion enhanced the ulcerative colitis alleviations of Lactiplantibacillus plantarum

Oral intake of probiotics is a promising approach to alleviate colitis. However, environmental sensitivity of the gastrointestinal tract and poor adhesion of probiotics to the intestine hamper the remedial effects. In this study, a simple yet effective novel probiotic multilayer coating consisting of Fe3+-protocatechuic acid (PCA) crosslinked network and Ca2+-induced sodium alginate (SA) for arming Lactiplantibacillus plantarum (LP) was developed. In the dextran sulfate sodium-induced colitis mouse model, SA-PCA-LP effectively alleviated colitis by regulating the expression of inflammatory cytokines, and repairing gut barriers. In addition, SA-PCA-LP regulated the gut microbiota and promoted the production of short-chain fatty acids, which further promoted the remission of colitis. Untargeted metabolomics also revealed that the scymnol, adenosine 5'-monophosphat, guanidylic acid, and 9H-purine-9-ol were significantly up-regulated in SA-PCA-LP group. In general, the novel coating strategies developed in the present study will motivate researchers to arm probiotics with various prebiotics to effectively alleviate colitis.

Treatment of ulcerative colitis via the in situ restoration of local immune and microbial homeostasis by oral administration of Tremella polysaccharide drug-carrying hydrogel

Ulcerative colitis (UC) is a prevalent inflammatory bowel disease, and conventional treatments, such as anti-inflammatory medications and surgery, often prove inadequate due to frequent recurrences and various complications. To alleviate patient suffering, there is an urgent need for a therapeutic system that specifically delivers drugs to the colon for wound healing, inflammation relief, and restoration of microbial homeostasis. In this paper, we developed a Tremella polysaccharide drug-carrying hydrogel that adheres to the inflamed colonic mucosa, forming an effective artificial barrier and releasing the drug in situ to restore local immune and microbial balance. The hydrogel backbone was synthesized through the chemical cross-linking of Tremella polysaccharide with 1,4-butanediol diglycidyl ether in an alkaline environment. During this process, Soluplus® and TPGS-encapsulated ginsenoside compound K adhered to the hydrogel backbone due to electrostatic attraction. The enhanced adhesion following cross-linking enables the hydrogel to stably attach to the inflamed colonic mucosa, releasing mixed micelles that improve drug penetration and absorption by inhibiting the cellular efflux protein P-glycoprotein. This mechanism promotes local immune recovery and eliminates harmful intestinal flora, providing significant relief from UC symptoms. This natural polysaccharide-based hydrogel represents a highly effective oral treatment for UC.

Antioxidant hydrogel from poly(aspartic acid) and carboxymethylcellulose with quercetin loading as burn wound dressing

Susceptibility to infection and excessive accumulation of reactive oxygen species (ROS) are the greatest obstacles for burn wound healing. In this research, the 5-aminosalicylic acid (ASA) grafted poly(aspartic hydrazide) (PASH) was synthesized by successive ploysuccinimide (PSI) ring opening reaction and reacted with oxidized carboxymethyl cellulose (DCMC) to fabricate biodegradable hydrogel through Schiff-base cross-linking. Moreover, the hydrogel was loaded with quercetin (QT) to enhance its anti-inflammatory performance. The ASA moiety endowed the hydrogel with the free radical scavenging ability and mussel inspired tissue adhesion to maintain the healing bioenvironment of the wound. The loading of QT gave the hydrogel more phenolic hydroxy group and further enhanced the antioxidant capacity of the hydrogel. The in vitro experiment revealed the grafted ASA moiety and the loaded QT greatly enhanced the ROS elimination property and antibacterial property. Moreover, the QT loaded hydrogel accelerated the burn wound repairing rate in the in vivo mice model. Based on above result, the PASH/DCMC could act as a new platform for QT loading to promote the burn wound repairing.

Layer by layer self-assembled hyaluronic acid nanoarmor for the treatment of ulcerative colitis

Natural compound-based treatments provide innovative ways for ulcerative colitis therapy. However, poor targeting and rapid degradation curtail its application, which needs to be addressed. Inspired by biomacromolecule-based materials, we have developed an orally administrated nanoparticle (GBP@HA NPs) using bovine serum albumin as a carrier for polyphenol delivery. The system synergizes galactosylated bovine serum albumin with two polyphenols, epigallocatechin gallate and tannic acid, which is then encased in "nanoarmor" of ε-Polylysine and hyaluronic acid to boost its stability and targeting. Remarkably, the nanoarmor demonstrated profound therapeutic effects in both acute and chronic mouse models of ulcerative colitis, mitigating disease symptoms via multiple mechanisms, regulating inflammation related factors and exerting a modulatory impact on gut microbiota. Further mechanistic investigations indicate that GBP@HA NPs may act through several pathways, including modulation of Keap1-Nrf2 and NF-κB signaling, as well as Caspase-1-dependent pyroptosis. Consequently, this novel armored nanotherapy promotes the way for enhanced polyphenol utilization in ulcerative colitis treatment research.

Extracellular Vesicles from Nanomedicine-Trained Intestinal Microbiota Substitute for Fecal Microbiota Transplant in Treating Ulcerative Colitis

The biosafety concerns associated with fecal microbiota transplant (FMT) limit their clinical application in treating ulcerative colitis (UC). Gut microbiota secrete abundant extracellular vesicles (Gm-EVs), which play a critical role in bacteria-to-bacteria and bacteria-to-host communications. Herein, intestinal microbiota are trained using tea leaf lipid/pluronic F127-coated curcumin nanocrystals (CN@Lp127s), which can maintain stability during transit through the gastrointestinal tract. Compared with FMT, Gm-EVs derived from healthy mice significantly improve treatment outcomes against UC by reducing colonic inflammatory responses, restoring colonic barrier function, and rebalancing intestinal microbiota. Strikingly, Gm-EVs obtained from CN@Lp127-trained healthy mice exhibit a superior therapeutic effect on UC compared to groups receiving FMT from healthy mice, Gm-EVs from healthy mice, and FMT from CN@Lp127-trained healthy mice. Oral administration of Gm-EVs from CN@Lp127-trained healthy mice not only alleviates colonic inflammation, promotes mucosal repair, and regulates gut microbiota but also regulates purine metabolism to decrease the uric acid level, resulting in a robust improvement in the UC. This study demonstrates the UC therapeutic efficacy of Gm-EVs derived from nanomedicine-trained gut microbiota in regulating the immune microenvironment, microbiota, and purine metabolism of the colon. These EVs provide an alternative platform to replace FMT as a treatment for UC.

Oral food-derived whey protein isolate-Tremella fuciformis polysaccharides pickering emulsions with adhesive ability to delivery magnolol for targeted treatment of ulcerative colitis

Magnolol (Mag) is a promising natural compound with therapeutic potential for ulcerative colitis (UC). Here we designed and fabricated an oral food-grade whey protein isolate-Tremella fuciformis polysaccharides (WPI-TFPS) stabilized pickering emulsions to encapsulate Mag (Mag-WPI-TFPS) for targeted treatment of UC. With the assistance of the WPI-TFPS, pickering emulsions were well encapsulated and formed stable microparticles with a particle size of approximately 9.49 ± 0.047 μm, a 93.63 ± 0.21 % encapsulation efficiency and a loading efficiency of 21.53 ± 0.01 %. In vitro, the formulation exhibited sustained-release properties in simulated colon fluid with a cumulative release rate of 60.78 % at 48 h. In vivo, the Mag-WPI-TFPS specifically accumulated in the colon tissue for 24 h with stronger fluorescence intensity, which demonstrated that TFPS and WPI had a good adherence ability to inflamed mucosa by electrostatic attraction and ligand-receptor interactions. As expected, compared with Free-Mag, the oral administration of Mag-WPI-TFPS remarkably alleviated the symptoms of UC and protected the colon tissue in DSS-induced UC mice. More importantly, WPI-TFPS enhanced gut microbiota balance by increasing the diversity and relative abundances of Lactobacillaceae and Firmicutes. Overall, this study presents a convenient, eco-friendly, food-derived oral formulation with potential as a dietary supplement for targeted UC treatment.

Acid-Resistant Nano-antioxidants Based on Epigallocatechin Gallate Alleviate Acute Intestinal and Kidney Inflammation

Epigallocatechin gallate (EGCG)-based nanosystems have garnered significant attention for their ability to alleviate inflammation due to their excellent anti-inflammatory properties and enhanced drug delivery capabilities. However, the degradation of EGCG in strongly acidic environments poses a challenge for potential administration, particularly in oral formulations, where gastric resistance is essential. In this study, we develop a "disintegration and reorganization" strategy to create acid-resistant antioxidant nanoparticles (EGA NPs) based on EGCG and 5-aminosalicylic acid (5-ASA) for mitigating inflammation in colitis and acute kidney injury. At acidic pH, the ester bond in EGCG breaks down, producing two building blocks. These, together with 5-ASA and formaldehyde, form oligomers through a combination of phenol-aldehyde condensation and the Mannich reaction. The resulting oligomers self-assemble into EGA NPs, which exhibit significant stability under both acidic and neutral pH conditions. This stability makes them suitable for oral administration, allowing them to withstand harsh gastric conditions, as well as for intravenous injection. Importantly, these oligomers retain the antioxidant and anti-inflammatory properties of EGCG, effectively scavenging reactive oxygen species and reducing intracellular oxidative stress. Additionally, EGA shows potential as a drug carrier, efficiently loading the anti-inflammatory agent curcumin (Cur) to form Cur@EGA NPs. In vivo studies demonstrate the efficacy of Cur@EGA and EGA in alleviating acute colitis and kidney injury following oral and intravenous administration, respectively. These nanoparticulate formulations exhibit superior inflammation reduction compared to free Cur in vivo. Overall, our findings introduce a novel acid-resistant nanoplatform based on EGCG for the treatment of acute inflammation.

Nanotechnology for Targeted Inflammatory Bowel Disease Therapy: Challenges and Opportunities

Inflammatory bowel disease (IBD) is a complex and recurring inflammatory disorder that affects the gastrointestinal tract and is influenced by genetic predisposition, immune dysregulation, the gut microbiota, and environmental factors. Advanced therapies, such as biologics and small molecules, target diverse immune pathways to manage IBD. Nanoparticle (NP)-based drugs have emerged as effective tools, offering controlled drug release and targeted delivery. This review highlights NP modifications for anti-inflammatory purposes, utilizing changes such as those in size, charge, redox reactions, and ligand-receptor interactions in drug delivery systems. By using pathological and microenvironmental cues to guide NP design, precise targeting can be achieved. In IBD, a crucial aspect of NP intervention is targeting specific types of cells, such as immune and epithelial cells, to address compromised intestinal barrier function and reduce overactive immune responses. This review also addresses current challenges and future prospects, with the goal of advancing the development of NP-mediated strategies for IBD treatment.

Colon Targeting pH-Responsive Coacervate Microdroplets for Treatment of Ulcerative Colitis

Ulcerative colitis (UC), an immune-mediated chronic inflammatory disease, drastically impacts patients' quality of life and increases their risk of colorectal cancer worldwide. However, effective oral targeted delivery and retention of drugs in colonic lesions are still great challenges in the treatment of UC. Coacervate microdroplets, formed by liquid-liquid phase separation, are recently explored in drug delivery as the simplicity in fabrication, spontaneous enrichment on small molecules and biological macromolecules, and high drug loading capacity. Herein, in this study, a biocompatible diethylaminoethyl-dextran hydrochloride/sodium polyphenylene sulfonate coacervates, coated with eudragit S100 to improve the stability and colon targeting ability, named EU-Coac, is developed. Emodin, an active ingredient in traditional Chinese herbs proven to alleviate UC symptoms, is loaded in EU-Coac (EMO@EU-Coac) showing good stability in gastric acid and pepsin and pH-responsive release behavior. After oral administration, EMO@EU-Coac can effectively target and retain in the colon, displaying good therapeutic effects on UC treatment through attenuating inflammation and oxidative stress response, repairing colonic epithelia, as well as regulating intestinal flora balance. In short, this study provides a novel and facile coacervate microdroplet delivery system for UC treatment.

Bioinspired and bioderived nanomedicine for inflammatory bowel disease

Due to its chronic nature and complex pathophysiology, inflammatory bowel disease (IBD) poses significant challenges for treatment. The long-term therapies for patients, often diagnosed between the ages of 20 and 40, call for innovative strategies to target inflammation, minimize systemic drug exposure, and improve patients' therapeutic outcomes. Among the plethora of strategies currently pursued, bioinspired and bioderived nano-based formulations have garnered interest for their safety and versatility in the management of IBD. Bioinspired nanomedicine can host and deliver not only small drug molecules but also biotherapeutics, be made gastroresistant and mucoadhesive or mucopenetrating and, for these reasons, are largely investigated for oral administration, while surprisingly less for rectal delivery, recommended first-line treatment approach for several IBD patients. The use of bioderived nanocarriers, mostly extracellular vesicles (EVs), endowed with unique homing abilities, is still in its infancy with respect to the arsenal of nanomedicine under investigation for IBD treatment. An emerging source of EVs suited for oral administration is ingesta, that is, plants or milk, thanks to their remarkable ability to resist the harsh environment of the upper gastrointestinal tract. Inspired by the unparalleled properties of natural biomaterials, sophisticated avenues for enhancing therapeutic efficacy and advancing precision medicine approaches in IBD care are taking shape, although bottlenecks arising either from the complexity of the nanomedicine designed or from the lack of a clear regulatory pathway still hinder a smooth and efficient translation to the clinics. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Gas-propelled nanomotors alleviate colitis through the regulation of intestinal immunoenvironment-hematopexis-microbiota circuits

The progression of ulcerative colitis (UC) is associated with immunologic derangement, intestinal hemorrhage, and microbiota imbalance. While traditional medications mainly focus on mitigating inflammation, it remains challenging to address multiple symptoms. Here, a versatile gas-propelled nanomotor was constructed by mild fusion of post-ultrasonic CaO2 nanospheres with Cu2O nanoblocks. The resulting CaO2-Cu2O possessed a desirable diameter (291.3 nm) and a uniform size distribution. It could be efficiently internalized by colonic epithelial cells and macrophages, scavenge intracellular reactive oxygen/nitrogen species, and alleviate immune reactions by pro-polarizing macrophages to the anti-inflammatory M2 phenotype. This nanomotor was found to penetrate through the mucus barrier and accumulate in the colitis mucosa due to the driving force of the generated oxygen bubbles. Rectal administration of CaO2-Cu2O could stanch the bleeding, repair the disrupted colonic epithelial layer, and reduce the inflammatory responses through its interaction with the genes relevant to blood coagulation, anti-oxidation, wound healing, and anti-inflammation. Impressively, it restored intestinal microbiota balance by elevating the proportions of beneficial bacteria (e.g., Odoribacter and Bifidobacterium) and decreasing the abundances of harmful bacteria (e.g., Prevotellaceae and Helicobacter). Our gas-driven CaO2-Cu2O offers a promising therapeutic platform for robust treatment of UC via the rectal route.

Recent progress on engineered micro/nanomaterials mediated modulation of gut microbiota for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a type of chronic recurrent inflammation disease that mainly includes Crohn's disease and ulcerative colitis. Currently, the treatments for IBD remain highly challenging, with clinical treatment drugs showing limited efficacy and adverse side effects. Thus, developing drug candidates with comprehensive therapeutic effects, high efficiency, and low toxicity is urgently needed. Recently, micro/nanomaterials have attracted considerable interest because of their bioavailability, multitarget and efficient effects on IBD. In addition, gut modulation plays a substantial role in restoring intestinal homeostasis. Therefore, efficient microbiota-based strategies modulating gut microenvironment have great potential in remarkably treating IBD. With the development of micro- and nanomaterials for the treatment of IBD and more in-depth studies of their therapeutic mechanisms, it has been found that these treatments also have a tendency to positively regulate the intestinal flora, resulting in an increase in the beneficial flora and a decrease in the level of pathogenic bacteria, thus regulating the composition of the intestinal flora to a normal state. In this review, we first present the interactions among the immune system, intestinal barrier, and gut microbiome. In addition, recent advances in administration routes and methods that positively arouse the regulation of intestinal flora for IBD using probiotics, prebiotics, and redox-active micro/nanomaterials have been reviewed. Finally, the key challenges and critical perspectives of gut microbiota-based micro/nanomaterial treatment are also discussed.

Recent advances in molecular mechanisms of skin wound healing and its treatments

The skin, being a multifaceted organ, performs a pivotal function in the complicated wound-healing procedure, which encompasses the triggering of several cellular entities and signaling cascades. Aberrations in the typical healing process of wounds may result in atypical scar development and the establishment of a persistent condition, rendering patients more vulnerable to infections. Chronic burns and wounds have a detrimental effect on the overall quality of life of patients, resulting in higher levels of physical discomfort and socio-economic complexities. The occurrence and frequency of prolonged wounds are on the rise as a result of aging people, hence contributing to escalated expenditures within the healthcare system. The clinical evaluation and treatment of chronic wounds continue to pose challenges despite the advancement of different therapeutic approaches. This is mainly owing to the prolonged treatment duration and intricate processes involved in wound healing. Many conventional methods, such as the administration of growth factors, the use of wound dressings, and the application of skin grafts, are used to ease the process of wound healing across diverse wound types. Nevertheless, these therapeutic approaches may only be practical for some wounds, highlighting the need to advance alternative treatment modalities. Novel wound care technologies, such as nanotherapeutics, stem cell treatment, and 3D bioprinting, aim to improve therapeutic efficacy, prioritize skin regeneration, and minimize adverse effects. This review provides an updated overview of recent advancements in chronic wound healing and therapeutic management using innovative approaches.

A Gas Therapy Strategy for Intestinal Flora Regulation and Colitis Treatment by Nanogel-Based Multistage NO Delivery Microcapsules

Current approaches to treating inflammatory bowel disease focus on the suppression of overactive immune responses, the removal of reactive intestinal oxygen species, and regulation of the intestinal flora. However, owing to the complex structure of the gastrointestinal tract and the influence of mucus, current small-molecule and biologic-based drugs for treating colitis cannot effectively act at the site of colon inflammation, and as a result, they tend to exhibit low efficacies and toxic side effects. In this study, nanogel-based multistage NO delivery microcapsules are developed to achieve NO release at the inflammation site by targeting the inflammatory tissues using the nanogel. Surprisingly, oral administration of the microcapsules suppresses the growth of pathogenic bacteria and increases the abundance of probiotic bacteria. Metabolomics further show that an increased abundance of intestinal probiotics promotes the production of metabolites, including short-chain fatty acids and indole derivatives, which modulate the intestinal immunity and restore the intestinal barrier via the interleukin-17 and PI3K-Akt signaling pathways. This work reveals that the developed gas therapy strategy based on multistage NO delivery microcapsules modulates the intestinal microbial balance, thereby reducing inflammation and promoting intestinal barrier repair, ultimately providing a new therapeutic approach for the clinical management of colitis.

Bioinspired and biomimetic strategies for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease with high morbidity and an increased risk of cancer or death, resulting in a heavy societal medical burden. While current treatment modalities have been successful in achieving long-term remission and reducing the risk of complications, IBD remains incurable. Nanomedicine has the potential to address the high toxic side effects and low efficacy in IBD treatment. However, synthesized nanomedicines typically exhibit some degree of immune rejection, off-target effects, and a poor ability to cross biological barriers, limiting the development of clinical applications. The emergence of bionic materials and bionic technologies has reshaped the landscape in novel pharmaceutical fields. Biomimetic drug-delivery systems can effectively improve biocompatibility and reduce immunogenicity. Some bioinspired strategies can mimic specific components, targets or immune mechanisms in pathological processes to produce targeting effects for precise disease control. This article highlights recent research on bioinspired and biomimetic strategies for the treatment of IBD and discusses the challenges and future directions in the field to advance the treatment of IBD.

Transient Mild Photothermia Improves Therapeutic Performance of Oral Nanomedicines with Enhanced Accumulation in the Colitis Mucosa

The treatment outcomes of oral medications against ulcerative colitis (UC) have long been restricted by low drug accumulation in the colitis mucosa and subsequent unsatisfactory therapeutic efficacy. Here, high-performance pluronic F127 (P127)-modified gold shell (AuS)-polymeric core nanotherapeutics loading with curcumin (CUR) is constructed. Under near-infrared irradiation, the resultant P127-AuS@CURs generate transient mild photothermia (TMP; ≈42 °C, 10 min), which facilitates their penetration through colonic mucus and favors multiple cellular processes, including cell internalization, lysosomal escape, and controlled CUR release. This strategy relieves intracellular oxidative stress, improves wound healing, and reduces immune responses by polarizing the proinflammatory M1-type macrophages to the anti-inflammatory M2-type. Upon oral administration of hydrogel-encapsulating P127-AuS@CURs plus intestinal intralumen TMP, their therapeutic effects against acute and chronic UC are demonstrated to be superior to those of a widely used clinical drug, dexamethasone. The treatment of P127-AuS@CURs (+ TMP) elevates the proportions of beneficial bacteria (e.g., Lactobacillus and Lachnospiraceae), whose metabolites can also mitigate colitis symptoms by regulating genes associated with antioxidation, anti-inflammation, and wound healing. Overall, the intestinal intralumen TMP offers a promising approach to enhance the therapeutic outcomes of noninvasive medicines against UC.

Protein Coronas Derived from Mucus Act as Both Spear and Shield to Regulate Transferrin Functionalized Nanoparticle Transcellular Transport in Enterocytes

The epithelial mucosa is a key biological barrier faced by gastrointestinal, intraoral, intranasal, ocular, and vaginal drug delivery. Ligand-modified nanoparticles demonstrate excellent ability on this process, but their efficacy is diminished by the formation of protein coronas (PCs) when they interact with biological matrices. PCs are broadly implicated in affecting the fate of NPs in vivo and in vitro, yet few studies have investigated PCs formed during interactions of NPs with the epithelial mucosa, especially mucus. In this study, we constructed transferrin modified NPs (Tf-NPs) as a model and explored the mechanisms and effects that epithelial mucosa had on PCs formation and the subsequent impact on the transcellular transport of Tf-NPs. In mucus-secreting cells, Tf-NPs adsorbed more proteins from the mucus layers, which masked, displaced, and dampened the active targeting effects of Tf-NPs, thereby weakening endocytosis and transcellular transport efficiencies. In mucus-free cells, Tf-NPs adsorbed more proteins during intracellular trafficking, which enhanced transcytosis related functions. Inspired by soft coronas and artificial biomimetic membranes, we used mucin as an "active PC" to precoat Tf-NPs (M@Tf-NPs), which limited the negative impacts of "passive PCs" formed during interface with the epithelial mucosa and improved favorable routes of endocytosis. M@Tf-NPs adsorbed more proteins associated with endoplasmic reticulum-Golgi functions, prompting enhanced intracellular transport and exocytosis. In summary, mucus shielded against the absorption of Tf-NPs, but also could be employed as a spear to break through the epithelial mucosa barrier. These findings offer a theoretical foundation and design platform to enhance the efficiency of oral-administered nanomedicines.

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

An Engineered Butyrate-Derived Polymer Nanoplatform as a Mucosa-Healing Enhancer Potentiates the Therapeutic Effect of Magnolol in Inflammatory Bowel Disease

Colonic epithelial damage and dysregulated immune response are crucial factors in the progression and exacerbation of inflammatory bowel disease (IBD). Nanoenabled targeted drug delivery to the inflamed intestinal mucosa has shown promise in inducing and maintaining colitis remission, while minimizing side effects. Inspired by the excellent antioxidative and anti-inflammatory efficacy of naturally derived magnolol (Mag) and gut homeostasis regulation of microbiota-derived butyrate, we developed a pH/redox dual-responsive butyrate-rich polymer nanoparticle (PSBA) as an oral Mag delivery system for combinational therapy of IBD. PSBA showed a high butyrate content of 22% and effectively encapsulated Mag. The Mag-loaded nanoparticles (PSBA@Mag) demonstrated colonic pH and reduction-responsive drug release, ensuring efficient retention and adhesion in the colon of colitis mice. PSBA@Mag not only normalized the level of reactive oxygen species and inflammatory effectors in inflamed colonic mucosa but also restored the epithelial barrier function in both ulcerative colitis and Crohn's disease mouse models. Importantly, PSBA promoted the migration and healing ability of intestinal epithelial cells in vitro and in vivo, sensitizing the therapeutic efficacy of Mag in animal models. Moreover, transcriptomics and metabolism analyses revealed that PSBA@Mag mitigated inflammation by suppressing the production of pro-inflammatory cytokines and chemokines and restoring the lipid metabolism. Additionally, this nanomedicine modulated the gut microbiota by inhibiting pathogenic Proteus and Escherichia-Shigella and promoting the proliferation of beneficial probiotics, including Lachnoclostridium, Lachnospiraceae_NK4A136_group and norank_f_Ruminococcaceae. Overall, our findings highlight the potential of butyrate-functionalized polymethacrylates as versatile and effective nanoplatforms for colonic drug delivery and mucosa repair in combating IBD and other gastrointestinal disorders.

Natural lipid nanoparticles extracted from Morus nigra L. leaves for targeted treatment of hepatocellular carcinoma via the oral route

The clinical application of conventional medications for hepatocellular carcinoma treatment has been severely restricted by their adverse effects and unsatisfactory therapeutic effectiveness. Inspired by the concept of 'medicine food homology', we extracted and purified natural exosome-like lipid nanoparticles (LNPs) from black mulberry (Morus nigra L.) leaves. The obtained MLNPs possessed a desirable hydrodynamic particle size (162.1 nm), a uniform size distribution (polydispersity index = 0.025), and a negative surface charge (-26.6 mv). These natural LNPs were rich in glycolipids, functional proteins, and active small molecules (e.g., rutin and quercetin 3-O-glucoside). In vitro experiments revealed that MLNPs were preferentially internalized by liver tumor cell lines via galactose receptor-mediated endocytosis, increased intracellular oxidative stress, and triggered mitochondrial damage, resulting in suppressing the viability, migration, and invasion of these cells. Importantly, in vivo investigations suggested that oral MLNPs entered into the circulatory system mainly through the jejunum and colon, and they exhibited negligible adverse effects and superior anti-liver tumor outcomes through direct tumor killing and intestinal microbiota modulation. These findings collectively demonstrate the potential of MLNPs as a natural, safe, and robust nanomedicine for oral treatment of hepatocellular carcinoma.

Transparent silk fibroin film-facilitated infected-wound healing through antibacterial, improved fibroblast adhesion and immune modulation

The clinical application of regenerated silk fibroin (RSF) films for wound treatment is restricted by its undesirable mechanical properties and lack of antibacterial activity. Herein, different pluronic polymers were introduced to optimize their mechanical properties and the RSF film with 2.5% pluronic F127 (RSFPF127) stood out to address the above issues owing to its satisfactory mechanical properties, hydrophilicity, and transmittance. Diverse antibacterial agents (curcumin, Ag nanoparticles, and antimicrobial peptide KR-12) were separately encapsulated in RSFPF127 to endow it with antibacterial activity. In vitro experiments revealed that the medicated RSFPF127 could persistently release drugs and had desirable bioactivities toward killing bacteria, promoting fibroblast adhesion, and modulating macrophage polarization. In vivo experiments revealed that medicated RSFPF127 not only eradicated methicillin-resistant Staphylococcus aureus in the wound area and inhibited inflammatory responses, but also facilitated angiogenesis and re-epithelialization, regardless of the types of antibacterial agents, thus accelerating the recovery of infected wounds. These results demonstrate that RSFPF127 is an ideal matrix platform to load different types of drugs for application as wound dressings.

Efficient oral delivery of resveratrol-loaded cyclodextrin-metal organic framework for alleviation of ulcerative colitis

Developing innovative strategies for the oral administration of phytochemicals presents a promising approach to addressing intestinal diseases. However, numerous challenges persist, including limited therapeutic efficacy, poor bioavailability, and inadequate biocompatibility. In this study, we employed a cross-linked cyclodextrin-metal organic framework (CDF) to encapsulate resveratrol (Res), generating Res-CDF, which was subsequently incorporated into natural polysaccharide hydrogel microspheres (Res-CDF in MPs) for targeted oral delivery to alleviate ulcerative colitis (UC). The underlying adsorption mechanism of Res by γ-CD elucidated by molecular dynamics simulations. Importantly, the Res-CDF in MPs formulation protected against gastric acid degradation while preserving the bioactivity of Res. Moreover, the design enabled specific release of Res-CDF in response to the mildly alkaline environment of the intestinal tract, followed by sustained Res release. In UC mice model, Res-CDF in MPs demonstrated potent anti-inflammatory effects by attenuating pro-inflammatory cytokine production and exhibited antioxidant properties. Additionally, Res-CDF in MPs enhanced the expression of tight junction proteins ZO-1, Occludin, and mucin-2 (Muc-2), thereby maintaining normal intestinal barrier function. This innovative oral delivery strategy capitalizes on the advantageous properties of polysaccharide hydrogel and CDF to augment bioavailability of phytochemicals, laying the groundwork for developing novel oral interventions employing natural phytochemicals to address intestinal-related diseases.

Marine biomaterials in biomedical nano/micro-systems

Marine resources in unique marine environments provide abundant, cost-effective natural biomaterials with distinct structures, compositions, and biological activities compared to terrestrial species. These marine-derived raw materials, including polysaccharides, natural protein components, fatty acids, and marine minerals, etc., have shown great potential in preparing, stabilizing, or modifying multifunctional nano-/micro-systems and are widely applied in drug delivery, theragnostic, tissue engineering, etc. This review provides a comprehensive summary of the most current marine biomaterial-based nano-/micro-systems developed over the past three years, primarily focusing on therapeutic delivery studies and highlighting their potential to cure a variety of diseases. Specifically, we first provided a detailed introduction to the physicochemical characteristics and biological activities of natural marine biocomponents in their raw state. Furthermore, the assembly processes, potential functionalities of each building block, and a thorough evaluation of the pharmacokinetics and pharmacodynamics of advanced marine biomaterial-based systems and their effects on molecular pathophysiological processes were fully elucidated. Finally, a list of unresolved issues and pivotal challenges of marine-derived biomaterials applications, such as standardized distinction of raw materials, long-term biosafety in vivo, the feasibility of scale-up, etc., was presented. This review is expected to serve as a roadmap for fundamental research and facilitate the rational design of marine biomaterials for diverse emerging applications.

Nanocrystalline Cellulose Modulates Dysregulated Intestinal Barriers in Ulcerative Colitis

Ulcerative colitis (UC) is a recurrent chronic inflammation of the colon with increasing incidence and prevalence, which could increase the risk of colorectal cancer. It is urgent to find an effective method with few side effects. Nanocrystalline cellulose (NCC), which is from plant fibers, has a good biocompatibility and high biosafety. Herein, we used NCC to treat UC and evaluated its treatment effect by the disease activity index, intestinal pathology, inflammatory cytokines, tight junction proteins, and mucins. We studied the impact of NCC on mucin expression and gut microbiota to discuss the therapeutic mechanism. NCC can effectively treat UC by regulating the MAPK pathway of mucin 2 and the relative abundance of Akkermansia and Odoribacter, which could not cause the body damage. NCC could not cause body damage compared to the medications, while it had a better effect on the regulation of MUC2 compared to the present drug substitutes. NCC is a practical alternative for the treatment of UC.

pH/enzyme dual sensitive Gegenqinlian pellets coated with Bletilla striata polysaccharide membranes for the treatment of ulcerative colitis

Gegen Qinlian Decoction, derived from Zhang Zhongjing's Treatise on Typhoid Fever, has been widely used in the treatment of various common diseases, frequently-occurring diseases and difficult and complicated diseases, such as ulcerative colitis. In this study, Bletilla striata polysaccharide (BSP) was innovatively used as a film coating material to prepare Gegen Qinlian pellets with dual sensitivity of pH enzyme for the treatment of ulcerative colitis. BSP has the ability to repair the inflamed colon mucosa and can produce synergistic effects, while avoiding the adverse therapeutic effects caused by the early release of drugs from a single pH-sensitive pellets in the small intestine. The prepared pellets have a uniform particle size, good roundness, a particle size range from 0.8 mm to 1.0 mm, and a particle yield is 85.6 %. The results of in vitro release showed that ES-BSP pellets hardly released drugs in the pH range of 1.2-6.8. However, in the colon mimic fluid containing specific enzymes, the drug release was significantly accelerated, demonstrating the sensitivity of the pellets to pH enzymes. In vivo and ex vivo fluorescence imaging of small animals showed that Gegen Qinlian pellets with dual sensitivity of pH enzyme remained longer in the colon compared with pH-sensitive pellets. In vivo pharmacodynamics study showed that the Gegen Qinlian pellets with dual sensitivity of pH enzyme had a better therapeutic effect in the rat model of the ulcerative colon than the commercially available Gegenqinlian pellets in the control group.

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

Despite the progress in the therapy of ulcerative colitis (UC), long-lasting UC remission can hardly be achieved in the majority of UC patients. The key pathological characteristics of UC include an impaired mucosal barrier and local inflammatory infiltration. Thus, a two-pronged approach aiming at repairing damaged mucosal barrier and scavenging inflammatory mediators simultaneously might hold great potential for long-term remission of UC. A rectal formulation can directly offer preferential and effective drug delivery to inflamed colon. However, regular intestinal peristalsis and frequent diarrhea in UC might cause transient drug retention. Therefore, a bioadhesive hydrogel with strong interaction with intestinal mucosa might be preferable for rectal administration to prolong drug retention. Here, we designed a bioadhesive hydrogel formed by the cross-linking of sulfhydryl chondroitin sulfate and polydopamine (CS-PDA). The presence of PDA would ensure the mucosa-adhesive behavior, and the addition of CS in the hydrogel network was expected to achieve the restoration of the intestinal epithelial barrier. To scavenge the key player (excessive reactive oxygen species, ROS) in inflamed colon, sodium ferulic (SF), a potent ROS inhibitor, was incorporated into the CS-PDA hydrogel. After rectal administration, the SF-loaded CS-PDA hydrogel could adhere to the colonic mucosa to allow prolonged drug retention. Subsequently, sustained SF release could be achieved to persistently scavenge ROS in inflammatory areas. Meanwhile, the presence of CS would promote the restoration of the mucosal barrier. Ultimately, scavenging ROS and restoring the mucosal barrier could be simultaneously achieved via this SF-loaded bioadhesive hydrogel scaffold. Our two-pronged approach might provide new insight for effective UC treatment.

Simulation of Cortical and Cancellous Bone to Accelerate Tissue Regeneration

Different tissues have complex anisotropic structures to support biological functions. Mimicking these complex structures in vitro remains a challenge in biomaterials designs in support of tissue regeneration. Here, inspired by different types of silk nanofibers, a composite materials strategy was pursued towards this challenge. A combination of fabrication methods was utilized to achieve separate control of amorphous and beta-sheet rich silk nanofibers in the same solution. Aqueous solutions containing these two structural types of silk nanofibers were then simultaneously treated with an electric field and with ethylene glycol diglycidyl ether (EGDE). Under these conditions, the beta-sheet rich silk nanofibers in the mixture responded to the electric field while the amorphous nanofibers were active in the crosslinking process with the EGDE. As a result, cryogels with anisotropic structures were prepared, including mimics for cortical- and cancellous-like bone biomaterials as a complex osteoinductive niche. In vitro studies revealed that mechanical cues of the cryogels induced osteodifferentiation of stem cells while the anisotropy inside the cryogels influenced immune reactions of macrophages. These bioactive cryogels also stimulated improved bone regeneration in vivo through modulation of inflammation, angiogenesis and osteogenesis responses, suggesting an effective strategy to develop bioactive matrices with complex anisotropic structures beneficial to tissue regeneration.

Structurally dynamic self-healable hydrogel cooperatively inhibits intestinal inflammation and promotes mucosal repair for enhanced ulcerative colitis treatment

Hydrogels are a class of biocompatible materials with versatile functions that have been increasing explored for the localized treatment of ulcerative colitis (UC), but various mechanical stimuli may cause premature hydrogel breakage and detachment, impeding their further clinical translation. Here we report a multifunctional mechanically-resilient self-healing hydrogel for effective UC treatment, which is synthesized through the host-guest interaction between dopamine/β-cyclodextrin-modified hyaluronic acid (HA-CD-DA) and amantadine-modified carboxymethyl chitosan (CMCS-AD). The excessive β-CD cavities allow the incorporation of dexamethasone (DEX), while the porous hydrogel network potentiates the encapsulation of basic fibroblast growth factor (bFGF) and L-alanyl-l-glutamine (ALG). DA moieties in HA components allow firm adhesion of the hydrogel to the ulcerative lesions after in-situ implantation, while the reversible host-guest interaction between CD and AD could enhance the persistence of hydrogel. The hydrogel demonstrated favorable biocompatibility and could continuously release DEX to induce M1-to-M2 repolarization of mucosal macrophages through inhibiting the toll-like receptor 4 (TLR4)-nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) axis. Furthermore, the co-delivered bFGF and ALG facilitates the regeneration of ulcerative mucosa and restore its barrier functions to ameliorate UC symptoms. The mechanically resilient hydrogel offers an integrative approach for UC therapy in the clinics.

Mulberry Biomass-Derived Nanomedicines Mitigate Colitis through Improved Inflamed Mucosa Accumulation and Intestinal Microenvironment Modulation

The therapeutic outcomes of conventional oral medications against ulcerative colitis (UC) are restricted by inefficient drug delivery to the colitis mucosa and weak capacity to modulate the inflammatory microenvironment. Herein, a fluorinated pluronic (FP127) was synthesized and employed to functionalize the surface of mulberry leaf-derived nanoparticles (MLNs) loading with resveratrol nanocrystals (RNs). The obtained FP127@RN-MLNs possessed exosome-like morphologies, desirable particle sizes (around 171.4 nm), and negatively charged surfaces (-14.8 mV). The introduction of FP127 to RN-MLNs greatly improved their stability in the colon and promoted their mucus infiltration and mucosal penetration capacities due to the unique fluorine effect. These MLNs could efficiently be internalized by colon epithelial cells and macrophages, reconstruct disrupted epithelial barriers, alleviate oxidative stress, provoke macrophage polarization to M2 phenotype, and down-regulate inflammatory responses. Importantly, in vivo studies based on chronic and acute UC mouse models demonstrated that oral administration of chitosan/alginate hydrogel-embedding FP127@RN-MLNs achieved substantially improved therapeutic efficacies compared with nonfluorinated MLNs and a first-line UC drug (dexamethasone), as evidenced by decreased colonic and systemic inflammation, integrated colonic tight junctions, and intestinal microbiota balance. This study brings new insights into the facile construction of a natural, versatile nanoplatform for oral treatment of UC without adverse effects.

Cyclosporine A-loaded colon-targeted oral nanomicelles self-assembly by galactosylated carboxymethyl chitosan for efficient ulcerative colitis therapy

An oral galactosylated carboxymethyl chitosan polymeric nanomicelles (Gal-N-CMCS NPs) embedded in chitosan-alginate hydrogel (CA-Gel) was developed to load cyclosporine A (CyA) as therapeutic agents against ulcerative colitis (UC). Galactose modified CMCS with macrophage targeting characteristic and CyA via a simple ultrasonication method to form Gal-N-CMCS/CyA NPs, and mixed CA-Gel to acquire the final formulation (Gal-N-CMCS/CyA Gel). The generated Gal-N-CMCS/CyA NPs displayed a desirable particle size (206.8 nm), negative surface charge (-19.5 mV), and high encapsulating efficiency (89.6%). The morphology and release profiles were also charactered by transmission electron microscope [1] and dialysis method, respectively. Strikingly, the mucus penetration of Gal-N-CMCS/CyA NPs exceeded 90% within 90 min. The Gal-N-CMCS NPs internalized by macrophages were 3.3-fold higher than CMCS-N NPs, thereby, enhancing the anti-inflammatory activities of NPs. Meanwhile, these NPs exhibited excellent biocompatibility, reduced the toxic effect of CyA, and targeting ability on inflammatory macrophages both in vitro and in vivo. Most importantly, in vivo studies revealed that CyA NPs could efficiently target the inflamed colon, remarkably alleviate inflammation, repair mucosal and reconstructed colonic epithelial barriers in UC mice induced by dextran sulfate sodium (DSS) via Toll-like receptor 4 -Nuclear factor kappa-B (TLR4-NF-κB) pathway. Our findings suggest that these high-performance and facilely fabricated Gal-N-CMCS/CyA NPs could be developed as a promising drug carrier for oral UC treatment.

Sprayable Berberine-Silk Fibroin Microspheres with Extracellular Matrix Anchoring Function Accelerate Infected Wound Healing through Antibacterial and Anti-inflammatory Effects

The conventional method of applying local medications for treating wound infections is often ineffective because of the dilution of drugs by the excess wound exudate. In addition, there have been insufficient studies investigating the adhesion between drug-loaded nanomaterials and cells or tissue. To address this intractable problem, berberine-silk fibroin microspheres (Ber@MPs) with an extracellular matrix-anchoring function were developed in this study. The microspheres were prepared from silk fibroin using the polyethylene glycol emulsion precipitation method. Subsequently, berberine was loaded onto the microspheres. Our results revealed that Ber@MPs firmly anchored to cells, continuously releasing berberine in the microenvironment. Moreover, both Ber@MPs and Ber@MPs-cell complexes exerted a strong and long-lasting antibacterial effect against Staphylococcus aureus and Staphylococcus epidermidis in the microenvironment, despite the large amount of wound exudate. In addition, Ber@MPs effectively resisted the inflammatory response induced by lipopolysaccharides and accelerated the migration of fibroblasts and neovascularization of endothelial cells cultured in inflammation-induced media. Finally, the in vivo experiments confirmed that the Ber@MP spray accelerated the healing of infected wounds via its antibacterial and anti-inflammatory effects. Therefore, this study provides a novel strategy for treating infected wounds in the presence of excess exudate.

Stimuli-responsive silk fibroin for on-demand drug delivery

Stimuli-responsive "smart" hydrogel biomaterials have attracted great attention in the biomedical field, especially in designing novel on-demand drug delivery systems. As a handful natural biomaterial approved by US Food and Drug Administration, silk fibroin (SF) has unique high temperature resistance as well as tunable structural composition. These properties make it one of the most ideal candidates for on-demand drug delivery. Meanwhile, recent advances in polymer modification and nanomaterials have fostered the development of various stimuli-responsive delivery systems. Here, we first review the recent advance in designing responsive SF-based delivery systems in different stimulus sources. These systems are able to release mediators in a desired manner in response to specific stimuli in active or passive manners. We then describe applications of these specially designed responsive delivery systems in wound healing, tumor therapy, as well as immunomodulation. We also discuss the future challenges and prospects of stimuli-responsive SF-based delivery systems.

Oral Metal-Free Melanin Nanozymes for Natural and Durable Targeted Treatment of Inflammatory Bowel Disease (IBD)

Oral antioxidant nanozymes bring great promise for inflammatory bowel disease (IBD) treatment. To efficiently eliminate reactive oxygen species (ROS), various metal-based nanozymes have been developed for the treatment of IBD but their practical applications are seriously impaired by unstable ROS-eliminating properties and potential metal ion leakage in the digestive tract. Here, the authors for the first time propose metal-free melanin nanozymes (MeNPs) with excellent gastrointestinal stability and biocompatibility as a favorable therapy strategy for IBD. Moreover, MeNPs have extremely excellent natural and long-lasting characteristics of targeting IBD lesions. In view of the dominant role of ROS in IBD, the authors further reveal that oral administration of MeNPs can greatly alleviate the six major pathological features of IBD: oxidative stress, endoplasmic reticulum stress, apoptosis, inflammation, gut barrier disruption, and gut dysbiosis. Overall, this strategy highlights the great clinical application prospects of metal-free MeNPs via harnessing ROS scavenging at IBD lesions, offering a paradigm for antioxidant nanozyme in IBD or other inflammatory diseases.

Unravelling the potential of insects for medicinal purposes - A comprehensive review

Entomotherapy, the use of insects for medicinal purposes, has been practised for centuries in many countries around the world. More than 2100 edible insect species are eaten by humans, but little is known about the possibility of using these insects as a promising alternative to traditional pharmaceuticals for treating diseases. This review offers a fundamental understanding of the therapeutic applications of insects and how they might be used in medicine. In this review, 235 insect species from 15 orders are reported to be used as medicine. Hymenoptera contains the largest medicinal insect species, followed by Coleoptera, Orthoptera, Lepidoptera, and Blattodea. Scientists have examined and validated the potential uses of insects along with their products and by-products in treating various diseases, and records show that they are primarily used to treat digestive and skin disorders. Insects are known to be rich sources of bioactive compounds, explaining their therapeutic features such as anti-inflammatory, antimicrobial, antiviral, and so on. Challenges associated with the consumption of insects (entomophagy) and their therapeutic uses include regulation barriers and consumer acceptance. Moreover, the overexploitation of medicinal insects in their natural habitat has led to a population crisis, thus necessitating the investigation and development of their mass-rearing procedure. Lastly, this review suggests potential directions for developing insects used in medicine and offers advice for scientists interested in entomotherapy. In future, entomotherapy may become a sustainable and cost-effective solution for treating various ailments and has the potential to revolutionize modern medicine.

Hyaluronic acid-functionalized redox-responsive organosilica nanoparticles for targeted resveratrol delivery to attenuate acrylamide-induced toxicity

The purpose of this study is to construct a redox-responsive and targeted nanoparticle to effectively deliver resveratrol (Res) for alleviating acrylamide (ACR) toxicity. Here, Res-loaded tetrasulfide-containing organosilica nanoparticles (DSMSNs) functionalized with hyaluronic acid on the surface (DSMSNs@Res@HA) were prepared. The DSMSNs@Res@HA nanoparticles were spherical with an encapsulation efficiency of 46.68 ± 1.64 % and a hydrated particle size of about 237.73 nm. As expected, DSMSNs@Res@HA were capable of significantly protecting PC12 cells against ACR-induced damage in oxidative stress, mitochondrial membrane potential decrease, and cell apoptosis compared with free Res and DSMSNs@Res at the equivalent dose. Moreover, DSMSNs@Res@HA could be biodegraded and released Res in response to GSH stimulus. In vivo experiments suggested that DSMSNs@Res@HA significantly reduced histological damage in the brain, liver, and kidney of rats compared with free Res and DSMSNs@Res. After oral administration of DSMSNs@Res@HA, the intestinal flora of ACR-treated rats could be effectively regulated by improving the species uniformity and abundance as well as recovering the species diversity. According to these findings, DSMSNs@Res@HA is worth further investigation as a potential therapeutic nanomedicine to alleviate ACR toxicity and restore gut microbiota diversity.

Mussel-inspired alkaline phosphatase-specific coating on orthopedic implants for spatiotemporal modulating local osteoimmune microenvironment to facilitate osseointegration

Inadequate initial osseointegration and consequent prosthesis loosening are the most severe complications after artificial arthroplasty. Proper immune responses are crucial for the successful implantation of artificial prostheses. Macrophages are central in osteoimmunomodulation because they exert distinct functions with highly plasticity. Herein, we developed an alkaline phosphatase (ALP) sensitive mussel-inspired coating on orthopedic implants for promoting osseointegration. First, the resveratrol-alendronate complexes were deposited on titanium implant surface through mussel-inspired interfacial interactions. Upon prosthesis implantation, macrophages first polarized towards M1 type to initiate inflammatory responses and bone regeneration. As osteogenesis progresses, increasing amounts of ALP secreted by osteoblasts was cleaved the resveratrol-alendronate complexes. Then, the released resveratrol further promoted osteogenic differentiation of BMSCs and induced locoregional macrophages M2 polarization. Our results demonstrated that the bioinspired osteoimmunomodulation coating remarkably facilitated the prosthesis-bone integration by spatiotemporally modulating macrophages switching from M1 to M2 polarization in response to a real-time healing signal during osteogenesis. In summary, the mussel-inspired osteoimmunomodulation coating technology may provide a new approach for promoting osseointegration after artificial arthroplasty.

Fabrication of Silk Hydrogel Scaffolds with Aligned Porous Structures and Tunable Mechanical Properties

The effectiveness of cell culture and tissue regeneration largely depends on the structural and physiochemical characteristics of tissue-engineering scaffolds. Hydrogels are frequently employed in tissue engineering because of their high-water content and strong biocompatibility, making them the ideal scaffold materials for simulating tissue structures and properties. However, hydrogels created using traditional methods have low mechanical strength and a non-porous structure, which severely restrict their application. Herein, we successfully developed silk fibroin glycidyl methacrylate (SF-GMA) hydrogels with oriented porous structures and substantial toughness through directional freezing (DF) and in situ photo-crosslinking (DF-SF-GMA). The oriented porous structures in the DF-SF-GMA hydrogels were induced by directional ice templates and maintained after photo-crosslinking. The mechanical properties, particularly the toughness, of these scaffolds were enhanced compared to the traditional bulk hydrogels. Interestingly, the DF-SF-GMA hydrogels exhibit fast stress relaxation and variable viscoelasticity. The remarkable biocompatibility of the DF-SF-GMA hydrogels was further demonstrated in cell culture. Accordingly, this work reports a method to prepare tough SF hydrogels with aligned porous structures, which can be extensively applied to cell culture and tissue engineering.