Dong Yun Lee

Despite the potential of extracellular vesicles (EVs) and therapeutic proteins as carriers and cargos for oral delivery, their precise functional integration remains a persistent challenge, thereby limiting synergistic therapeutic outcomes. Here, we present a protein-hybrid, orally delivered EV strategy that integrates naturally bioactive EVs with self-loadable, backbone-cyclized immunoregulatory proteins for inflammatory bowel disease (IBD) therapy. Through computationally guided design and split intein-mediated backbone cyclization, we generated cyclized variants of key immunoregulatory proteins with improved functionality. Among these, C-R₄-tagged cyclization of phosphatase domain of T-cell protein tyrosine phosphatase (ppTCPTP) improved membrane permeability, thermal stability, and anti-inflammatory activity. This backbone cyclization enabled efficient and high-capacity loading of ppTCPTP into native EVs that are not amenable to genetic engineering. Notably, these protein-hybrid EVs exhibited acidic resistance for oral delivery and synergistically enhanced antioxidant and anti-inflammatory effects in murine IBD organoids and in vivo colitis models, markedly reducing intestinal inflammation and restoring epithelial barrier integrity. Our findings highlight the translational potential of this self-loadable protein-EV platform as a safe and potent oral biologic for IBD therapy.

Chronic diabetic wounds present substantial clinical challenges owing to sustained inflammation, compromised vascularization, and inadequate retention of therapeutic medications. Accordingly, motivated by mesenchymal stem cells (MSCs) that actively secrete bioactive exosomes in response to stimuli from the tissue microenvironment, a biomimetic microneedle (MN) platform (MSCi@MN) is created to address these challenges. The MSCi@MN exhibits a dual‐compartment structure composed of MSC‐derived extracellular nanovesicles (NV) conjugated with polydeoxyribonucleotide (PDRN; DNA), referred to as NV‐DNA, encapsulated within dissolvable MN tips, and photothermal‐responsive MXene nanoparticles (MX) incorporated into the base layer for targeted near‐infrared (NIR)‐activated drug delivery. Upon NIR irradiation, MSCi@MN quickly releases NV‐DNA, effectively modifying the immune responses by facilitating anti‐inflammatory M2 macrophage polarization and activating tolerogenic dendritic cells, thereby establishing a regenerative microenvironment. Transcriptomic research has verified that NV‐DNA synergistically promotes angiogenesis, cellular proliferation, and extracellular matrix remodeling by activating complementary molecular pathways. In animal models of diabetes, MSCi@MNs markedly expedite wound repair, diminish inflammation, enhance angiogenesis, and restore skin appendages without systemic adverse effects. This MSC‐inspired approach, which integrates biologically sensitive controlled release with robust immunoregenerative capabilities, has substantial potential for clinical use in chronic wound treatment and regenerative medicine.

To overcome Type 1 diabetes mellitus (T1DM), which can cause hyperglycemia due to diminished insulin secretion of β-cell function, islet transplantation has been developed with various strategies including pseudo-islet. However, conventional pseudo-islet formation techniques combining with other cells depend on natural cellular aggregation, which requires at least 5 days to form and even show segregation of distinct cell types, leading to diminished cell viability and function. Herein, we applied a subaqueous free-standing 3D cell culture (FS) device, which can reduce the spheroid formation time by trapped cell in nodes of acoustic standing wave. Briefly, Culturing with adipose-derived stem cells (ADSCs) to form heterotypic pseudo-islet (Hislet) in FS device dramatically reduced formation time less than one day. Hislet demonstrated enhancement of cell viability than conventional pseudo-islet formation method. Additionally, ADSCs combined Hislet proved strong secretion of various paracrine factors. Also results showed significantly increased angiogenesis effect and immunomodulation effect for various type of immune cells in Hislet compared to islet, which can enhance transplantation survival. Furthermore, Hislet validated glucose-regulating capacity and enhanced angiogenesis effect in vivo T1DM model. Throughout this study, we propose a novel strategy for forming Hislet that can overcome the limitations of conventional Islet and pseudo-islet for T1DM.

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder characterized by severe oxidative stress and intestinal barrier dysfunction. Conventional oral therapies are often limited by low bioavailability and off-target effects. Herein, we report the development of mucoadhesive nanotherapeutics engineered from low molecular weight chitosan oligosaccharide (COS) and glycyrrhizin (GL), a natural anti-inflammatory compound. Hydrophilic COS, selected for its potent antioxidant and mucoadhesive properties, was chemically conjugated with hydrophobic GL to facilitate self-assembly into stable COS-GL nanoparticles (∼129 nm). These nanoparticles exhibit enhanced retention at inflamed intestinal sites and preferential uptake by activated immune and epithelial cells. In vitro evaluations using transwell coculture systems and intestinal organoids revealed that COS-GL nanoparticles effectively suppress pro-inflammatory cytokine secretion, promote M1-to-M2 macrophage remodeling, neutralize reactive oxygen species (ROS), and restore intestinal barrier integrity by upregulating tight junction proteins. In a DSS-induced colitis mouse model, orally administered COS-GL nanoparticles outperform both their individual components and the standard therapeutic 5-aminosalicylic acid (5-ASA), mitigating inflammation and promoting mucosal healing. These findings establish COS-GL nanoparticles as a promising and effective nanotherapeutic platform for the targeted oral treatment of IBD.

Background: Pancreatic islet transplantation holds great potential as a therapeutic approach for treating type 1 diabetes mellitus (T1D). However, large islets suffer from hypoxia due to the limited diffusion distance of oxygen, leading to cell loss. Therefore, smaller spheroids are needed for better transplantation outcomes. This study aims to develop a method for forming highly functional islet spheroids using glycol chitosan (GC) derivatives, such as N-acetylated glycol chitosan (AGC) and N-hexanoyl glycol chitosan (HGC). Methods: Thermogelling polymers were produced by performing N-acylation of GC using the correspondingly carboxylic anhydrides. Islet spheroids were formed using a dual application with AGC-coated plates and HGC gelation. The AGC solution was applied to the plate for coating and evenly distributed using a 1 mL syringe. Then, the HGC encapsulated with islet single cells was cultured on top of it. Spheroid viability and functionality were evaluated using CCK-8 assay and glucose-stimulated insulin secretion assay. Results: The aqueous solutions of AGC (4%, w/v) and HGC (36% hexanoylation) (2%, w/v) demonstrated a sol–gel transition temperature around 37 °C, suitable for the physiological environment. These polymers also showed no cytotoxicity to intact islets. Islet single cells were cultured on HGC gels with varying degrees of hexanoylation (DH) values, where higher DH values led to smaller and more uniform spheroids. The resulting spheroids formed on AGC-coated plates and HGC36 gelation were smaller and more uniform than those formed on untreated plates. These spheroids exhibited significantly improved glucose responsiveness, with superior insulin secretion. Conclusion: The optimized method using AGC and HGC offers a more efficient way to produce smaller, uniform, and functional spheroids.