"Two-birds-one-stone" oral nanotherapeutic designed to target intestinal integrins and regulate redox homeostasis for UC treatment

Orally-deliverable liposome-microgel complexes dynamically remodel intestinal environment to enhance probiotic ulcerative colitis therapy via TLR4 inhibition and tryptophan metabolic crosstalk

Probiotics emerges as a promising option for ulcerative colitis (UC) treatment, but its application remains challenging due to insufficient colon-targeted delivery efficiency and survival against the inflammation-associated intestinal oxidative stress. To address these issues, here we report a supramolecular liposome-microgel complex (SLMC) incorporated with Bacillus subtilis spores (BSSs) and dexamethasone (DEX) for orally-deliverable probiotic UC therapy. Specifically, BSSs and cholesterols were conjugated with gelatin via diselenide ligation to prepare microgels, followed by supramolecular complexation with UC-targeted DEX-loaded liposome via microfluidic engineering. The orally-administered SLMC efficiently accumulated in UC-affected colonic sites to release BSSs and DEX. DEX elicited rapid anti-inflammatory effect to reduce ROS generation, which cooperated with the ROS consumption by spore germination and diselenide cleavage to orchestrate an anaerobic intestinal microenvironment, thus promoting Bacillus subtilis colonization to restore gut homeostasis and initiate anti-inflammatory microbiota-macrophage metabolic crosstalk. Indeed, in vivo analysis showed that the SLMC treatment markedly inhibited pro-inflammatory TLR4-NF-κB signaling activities in mucosal macrophages through localized DEX delivery and boosting tryptophan metabolite production, leading to robust and durable UC abolishment. This study offers a practical approach for improving UC treatment in the clinic.

Chiral Zinc Sulfide Nanoparticles Scavenging Reactive Oxygen Species for Remodeling Intestinal Homeostasis

Elevated levels of reactive oxygen species (ROS) and gut microbiota dysbiosis are crucial factors that exacerbate inflammatory bowel disease (IBD). To address this, we successfully synthesized zinc sulfide nanoparticles (ZnS NPs) with a particle size of approximately 500 nm and a maximum g-factor of 0.07, utilizing l-/d-cysteine as chiral ligands. Chirality gives NPs unique bioactivity. These chiral ZnS NPs could enter macrophages through the CD44 and clathrin pathways, which enhanced the ability to scavenge ROS, in turn significantly inhibited the NF-κB and NLRP3 signaling pathways, thereby reducing the secretion of TNF-α, IL-6, and IL-1β, while upregulating IL-10. In vivo experimental data showed that l-ZnS NPs outperformed 5-aminosalicylic acid, significantly improving body weight, reducing the IBD activity index, and attenuating tissue damage. Concurrently, l-ZnS NPs exhibited a marked prophylactic effect. The benchmark studies verified that l-ZnS NPs increased the abundance of the beneficial Lachnospiraceae NK4A136 by 10.55-fold and decreased harmful Enterobacter by 2914.00-fold, thereby reshaping the intestinal microecological balance. Pharmacokinetic and biosafety assessments confirmed the safety of l-ZnS NPs. Our findings indicate that chiral ZnS NPs hold great potential as nanodrugs for the treatment and prevention of IBD, providing an important foundation for the development of IBD therapeutic strategies.

Advanced oral drug delivery systems for gastrointestinal targeted delivery: the design principles and foundations

Oral administration has long been considered the most convenient method of drug delivery, requiring minimal expertise and invasiveness. Unlike injections, it avoids discomfort, wound infections, and complications, leading to higher patient compliance. However, the effectiveness of oral delivery is often hindered by the harsh biological barriers of the gastrointestinal tract, which limit the bioaccessibility and bioavailability of drugs. The development of oral drug delivery systems (ODDSs) represents a critical area for the advancement of pharmacotherapy. This review highlights the characteristics and precise targeting mechanisms of ODDSs. It first examines the unique properties of each gastrointestinal compartment, including the stomach, small intestine, intestinal mucus, intestinal epithelial barrier, and colon. Based on these features, it outlines the targeting strategies and design principles for ODDSs aimed at overcoming gastrointestinal barriers to enhance disease treatment. Lastly, the review discusses the challenges and potential future directions for ODDS development, emphasizing their importance for advancing drug delivery technologies and accelerating their future growth.

Stimulus-responsive nanomaterials for ocular antimicrobial therapy

Nanomaterials exhibit a promising new avenue for treating infectious keratitis, having garnered considerable interest in the ophthalmic medical community due to their unique properties including higher target specificity, enhanced bioactivity of loaded agents, reduced drug dosage, and stimulus-responsive drug release. These stimulus-responsive nanomaterial-mediated therapeutic strategies offer innovative approaches for managing ocular antimicrobial diseases. In this review, we aim to summarize current applications of stimulus-responsive nanotherapeutics for ocular antimicrobial therapy. We briefly introduce the basic ocular structure, ocular barrier, infectious keratitis classification, and its microenvironment. Following this, we summarize the nanotherapeutic antimicrobial strategies employed in treating ocular infections including endogenous stimulus-responsive ocular nanodrugs, sonodynamic therapy, and wearable device-based therapy, focusing on their design principles, developmental progress, and advantages and limitations. Finally, we critically evaluate the biosafety profiles of responsive nanomaterials, specifically addressing cytotoxicity and immune interactions. To conclude, we discuss key challenges in this research field and future opportunities with explicit emphasis on clinical translation and practical medical applications.

A versatile nanoplatform with excellent biofilm permeability and spatiotemporal ROS regulation for peri-implantitis treatment

Rationale: Dental implant restoration is essential for rehabilitating dentition defects. However, peri-implantitis (PI) seriously threatens the long-term stability of implants. Treating PI requires the complete eradication of plaque biofilm and the meticulous modulation of inflammatory responses. Antibacterial photodynamic therapy (aPDT) presents a promising potential in the antibacterial realm. Nonetheless, traditional aPDT for PI faces challenges such as inadequate biofilm penetration and distribution of photosensitizers, as well as a lack of precise bacteria targeting. Moreover, the excessive ROS generated by aPDT will aggravate the oxidative stress of peri-implant tissues, and this issue cannot be neglected. Methods: The CuTA-Por@ε-PL nanoplatforms (CPP NPs) were synthesized and characterized using dynamic light scattering, transmission electron microscopy, and dye probes in detail. The antibacterial and anti-inflammatory activities of CPP NPs were evaluated both in vitro and in vivo. Moreover, the in vivo therapeutic efficacy was successively analyzed through micro-CT, hematoxylin and eosin staining, Masson's staining, immunofluorescence staining, and colony formation units (CFU), among other techniques. Results: Porphyrin (Por), CuTA nanozyme with SOD/CAT activities, and ε-Polylysine (ε-PL) were combined to fabricate CPP NPs via a straightforward approach. The notable positive charge of CPP NPs facilitated biofilm penetration, distribution and precise bacteria targeting. Then, irradiation with a 660 nm laser triggered a ROS burst for biofilm elimination. After aPDT, CPP NPs scavenged the residual ROS and modulated host immunity by regulating macrophage polarization. As a result, CPP-treated groups demonstrated the most outstanding antibacterial and anti-inflammatory performance in the rat PI model. Conclusions: Given the pathogenesis of PI, this strategy rationally designed a multifunctional NP with antibacterial and anti-inflammatory functions via spatiotemporal ROS regulation. It provides a potentially novel approach for PI treatment, which may have a profound impact on improving the prognosis of patients with PI and advancing the field of implant dentistry.

Oral Akkermansia muciniphila Biomimetic Nanotherapeutics for Ulcerative Colitis Targeted Treatment by Repairing Intestinal Epithelial Barrier and Restoring Redox Homeostasis

The structural disruption of intestinal barrier and excessive reactive oxygen/nitrogen species (RONS) generation are two intertwined factors that drive the occurrence and development of ulcerative colitis (UC). Synchronously restoring the intestinal barrier and mitigating excess RONS is a promising strategy for UC management, but its treatment outcomes are still hindered by low drug accumulation and retention in colonic lesions. Inspired by intestine colonizing bacterium, we developed a mucoadhesive probiotic Akkermansia muciniphila-mimic entinostat-loaded hollow mesopores prussian blue (HMPB) nanotherapeutic (AM@HMPB@E) for UC-targeted therapy via repairing intestinal barrier and scavenging RONS. After oral administration, the negatively charged AM@HMPB@E specifically bind to the positively charged inflamed colon lesions via electrostatic interactions and Akkermansia muciniphila membrane-mediated bioadhesion mechanism. Subsequently, the superoxide dismutase (SOD)-, and catalase (CAT)-like HMPB eliminated RONS, thereby alleviating RONS-mediated inflammation and intestinal epithelial damage. Meanwhile, the UC-site locally released entinostat could repair the damaged intestinal epithelial barrier by inhibiting intestinal endothelial cell apoptosis and up-regulating the expression of tight junctions. Both in vitro and in vivo results shown that AM@HMPB@E not only exhibited an exceptional retention in the colitis site but also demonstrated superior therapeutic efficacy compared to the first-line drug sulfasalazine, as evidenced by the longer colon, less rectal bleeding and body weight loss. Collectively, our findings highlight the clinical application prospects of this synchronous nanotherapeutic strategy for UC treatment, offering a paradigm for the rational design of oral nanomedicine.

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.