Hydrophobic, ultraviolet radiation-shielding, and antioxidant functionalities of TEMPO-oxidized cellulose nanofibril film coated with modified lignin nanoparticles.

In this study, lignin nanoparticles (LN) and octadecylamine-modified LN (LN-ODA) were utilized as coating materials to enhance the hydrophobic, antioxidant, and ultraviolet radiation-shielding (UV-shielding) properties of a TEMPO-oxidized nanocellulose film (TOCNF). The water contact angle (WCA) of the TOCNF was approximately 53° and remained stable for 1 min, while the modified LN-ODA-coated TOCNF reached over 130° and maintained approximately 85° for an hour. Pure TOCNF exhibited low antioxidant properties (4.7 %), which were significantly enhanced in TOCNF-LN (81.6 %) and modified LN-ODA (10.3 % to 27.5 %). Modified LN-ODA-coated TOCNF exhibited antioxidant properties two to six times higher than those of pure TOCNF. Modified LN-ODA exhibited thermal degradation max (Tmax) at 421 °C, while pure LN showed the main degradation temperature at approximately Tmax 330 °C. The thermal stability of TOCNF-LN-ODA-coated materials remained consistent with that of pure TOCNF, while the crystallinity index of the sample showed a slight decrease due to the amorphous nature of the lignin structure. The tensile strength of TOCNF was approximately 114.1 MPa and decreased to 80.1, 51.3, and 30.3 MPa for LN-ODA coating at 5, 10, and 15 g/m2, respectively.

Bioengineering toolkits for potentiating organoid therapeutics.

Organoids are three-dimensional, multicellular constructs that recapitulate the structural and functional features of specific organs. Because of these characteristics, organoids have been widely applied in biomedical research in recent decades. Remarkable advancements in organoid technology have positioned them as promising candidates for regenerative medicine. However, current organoids still have limitations, such as the absence of internal vasculature, limited functionality, and a small size that is not commensurate with that of actual organs. These limitations hinder their survival and regenerative effects after transplantation. Another significant concern is the reliance on mouse tumor-derived matrix in organoid culture, which is unsuitable for clinical translation due to its tumor origin and safety issues. Therefore, our aim is to describe engineering strategies and alternative biocompatible materials that can facilitate the practical applications of organoids in regenerative medicine. Furthermore, we highlight meaningful progress in organoid transplantation, with a particular emphasis on the functional restoration of various organs.

Recent advances in micro-physiological systems for investigating tumor metastasis and organotropism.

Tumor metastasis involves complex processes that traditional 2D cultures and animal models struggle to fully replicate. Metastatic tumors undergo a multitude of transformations, including genetic diversification, adaptation to diverse microenvironments, and modified drug responses, contributing significantly to cancer-related mortality. Micro-physiological systems (MPS) technology emerges as a promising approach to emulate the metastatic process by integrating critical biochemical, biomechanical, and geometrical cues at a microscale. These systems are particularly advantageous simulating metastasis organotropism, the phenomenon where tumors exhibit a preference for metastasizing to particular organs. Organotropism is influenced by various factors, such as tumor cell characteristics, unique organ microenvironments, and organ-specific vascular conditions, all of which can be effectively examined using MPS. This review surveys the recent developments in MPS research from the past five years, with a specific focus on their applications in replicating tumor metastasis and organotropism. Furthermore, we discuss the current limitations in MPS-based studies of organotropism and propose strategies for more accurately replicating and analyzing the intricate aspects of organ-specific metastasis, which is pivotal in the development of targeted therapeutic approaches against metastatic cancers.

Brain-Decellularized ECM-Based 3D Myeloid Sarcoma Platform: Mimicking Adaptive Phenotypic Alterations in the Brain.

Leukemia circulates in the bloodstream and induces various symptoms and complications. Occasionally, these cells accumulate in non-marrow tissues, forming a tumor-like myeloid sarcoma (MS). When the blast-stage leukemia cells invade the brain parenchyma, intracranial MS occurs, leading to a challenging prognosis owing to the limited penetration of cytostatic drugs into the brain and the development of drug resistance. The scarcity of tissue samples from MS makes understanding the phenotypic changes occurring in leukemia cells within the brain environment challenging, thereby hindering development of effective treatment strategies for intracranial MS. This study presents a novel 3D in vitro model mimicking intracranial MS, employing a hydrogel scaffold derived from the brain-decellularized extracellular matrix in which suspended leukemia cells are embedded, simulating the formation of tumor masses in the brain parenchyma. This model reveals marked phenotypic changes in leukemia cells, including altered survival, proliferation, differentiation, and cell cycle regulation. Notably, proportion of dormant leukemia stem cells increases and expression of multidrug resistance genes is upregulated, leading to imatinib resistance, mirroring the pathological features of in vivo MS tissue. Furthermore, suppression of ferroptosis is identified as an important characteristic of intracranial MS, providing valuable insights for the development of targeted therapeutic strategies.

Enrichment of Deleterious Mutated Genes Involved in Ciliary Function and Histone Modification in Brain Cancer Patient-Derived Xenograft Models.

Patient-derived xenograft (PDX) models, which can retain the characteristics of original tumors in an in vivo-mimicking environment, have been developed to identify better treatment options. However, although original tumors and xenograft tissues mostly share oncogenic mutations and global gene expression patterns, their detailed mutation profiles occasionally do not overlap, indicating that selection occurs in the xenograft environment. To understand this mutational alteration in xenografts, we established 13 PDX models derived from 11 brain tumor patients and confirmed their histopathological similarity. Surprisingly, only a limited number of somatic mutations were shared between the original tumor and xenograft tissue. By analyzing deleteriously mutated genes in tumors and xenografts, we found that previously reported brain tumor-related genes were enriched in PDX samples, demonstrating that xenografts are a valuable platform for studying brain tumors. Furthermore, mutated genes involved in cilium movement, microtubule depolymerization, and histone methylation were enriched in PDX samples compared with the original tumors. Even with the limitations of the heterogeneity of clinical lesions with a heterotropic model, our study demonstrates that PDX models can provide more information in genetic analysis using samples with high heterogeneity, such as brain tumors.

Predicting response to anti-EGFR antibody, cetuximab, therapy by monitoring receptor internalization and degradation.

Anti-epidermal growth factor receptor (EGFR) antibody, cetuximab, therapy has significantly improved the clinical outcomes of patients with colorectal cancer, but the response to cetuximab can vary widely among individuals. We thus need strategies for predicting the response to this therapy. However, the current methods are unsatisfactory in their predictive power. Cetuximab can promote the internalization and degradation of EGFR, and its therapeutic efficacy is significantly correlated with the degree of EGFR degradation. Here, we present a new approach to predict the response to anti-EGFR therapy, cetuximab by evaluating the degree of EGFR internalization and degradation of colorectal cancer cells in vitro and in vivo. Our newly developed fluorogenic cetuximab-conjugated probe (Cetux-probe) was confirmed to undergo EGFR binding, internalization, and lysosomal degradation to yield fluorescence activation; it thus shares the action mechanism by which cetuximab exerts its anti-tumor effects. Cetux-probe-activated fluorescence could be used to gauge EGFR degradation and showed a strong linear correlation with the cytotoxicity of cetuximab in colorectal cancer cells and tumor-bearing mice. The predictive ability of Cetux-probe-activated fluorescence was much higher than those of EGFR expression or KRAS mutation status. The Cetux-probes may become useful tools for predicting the response to cetuximab therapy by assessing EGFR degradation.

Endoscopically injectable and self-crosslinkable hydrogel-mediated stem cell transplantation for alleviating esophageal stricture after endoscopic submucosal dissection.

Esophageal stricture after extensive endoscopic submucosal dissection impairs the quality of life of patients with superficial esophageal carcinoma. Beyond the limitations of conventional treatments including endoscopic balloon dilatation and the application of oral/topical corticosteroids, several cell therapies have been recently attempted. However, such methods are still limited in clinical situations and existing setups, and the efficacies are less in some cases since the transplanted cells hardly remain at the resection site for a long time due to swallowing and peristalsis of the esophagus. Thus, a cell transplantation platform directly applicable with clinically established equipment and enabling stable retention of transplanted cells can be a promising therapeutic option for better clinical outcomes. Inspired by ascidians that rapidly self-regenerate, this study demonstrates endoscopically injectable and self-crosslinkable hyaluronate that allows both endoscopic injection in a liquid state and self-crosslinking as an in situ-forming scaffold for stem cell therapy. The pre-gel solution may compatibly be applied with endoscopic tubes and needles of small diameters, based on the improved injectability compared to the previously reported endoscopically injectable hydrogel system. The hydrogel can be formed via self-crosslinking under in vivo oxidative environment, while also exhibiting superior biocompatibility. Finally, the mixture containing adipose-derived stem cells and the hydrogel can significantly alleviate esophageal stricture after endoscopic submucosal dissection (75% of circumference, 5 cm in length) in a porcine model through paracrine effects of the stem cell in the hydrogel, which modulate regenerative processes. The stricture rates on Day 21 were 79.5% ± 2.0%, 62.8% ± 1.7%, and 37.9% ± 2.9% in the control, stem cell only, and stem cell-hydrogel groups, respectively (p < 0.05). Therefore, this endoscopically injectable hydrogel-based therapeutic cell delivery system can serve as a promising platform for cell therapies in various clinically relevant situations.

MSH2-MSH3 promotes DNA end resection during homologous recombination and blocks polymerase theta-mediated end-joining through interaction with SMARCAD1 and EXO1.

DNA double-strand break (DSB) repair via homologous recombination is initiated by end resection. The extent of DNA end resection determines the choice of the DSB repair pathway. Nucleases for end resection have been extensively studied. However, it is still unclear how the potential DNA structures generated by the initial short resection by MRE11-RAD50-NBS1 are recognized and recruit proteins, such as EXO1, to DSB sites to facilitate long-range resection. We found that the MSH2-MSH3 mismatch repair complex is recruited to DSB sites through interaction with the chromatin remodeling protein SMARCAD1. MSH2-MSH3 facilitates the recruitment of EXO1 for long-range resection and enhances its enzymatic activity. MSH2-MSH3 also inhibits access of POLθ, which promotes polymerase theta-mediated end-joining (TMEJ). Collectively, we present a direct role of MSH2-MSH3 in the initial stages of DSB repair by promoting end resection and influencing the DSB repair pathway by favoring homologous recombination over TMEJ.

Adhesive Hydrogel Patch-Mediated Combination Drug Therapy Induces Regenerative Wound Healing through Reconstruction of Regenerative Microenvironment.

Regenerative wound healing involves the scarless wound healing as observed in fetal skin. Multiple features of regenerative wound healing have been well studied; however, the practical application of pro-regenerative materials to recapitulate the regenerative wound healing in adult skins has not yet been achieved. In this study, the authors identified that their novel pro-regenerative material, pyrogallol-functionalized hyaluronic acid (HA-PG) patches in combination with protein transduction domain-fused Dishevelled (Dvl)-binding motif (PTD-DBM), a peptide inhibiting the CXXC-type zinc finger protein 5 (CXXC5)-Dvl interaction, promoted regenerative wound healing in mice. The HA-PG patches loaded with this competitor peptide and valproic acid (VPA), a glycogen synthase kinase 3ß (GSK3ß) inhibitor, significantly inhibited scar formation during wound healing. The HA-PG patches with PTD-DBM and/or VPA inhibit the expression of differentiated cell markers such as α-smooth muscle actin (α-SMA) while inducing the expression of stem cell markers such as CD105 and Nestin. Moreover, Collagen III, an important factor for regenerative healing, is critically induced by the HA-PG patches with PTD-DBM and/or VPA, as also seen in VPA-treated Cxxc5-/- mouse fibroblasts. Overall, these findings suggest that the novel regeneration-promoting material can be utilized as a potential therapeutic agent to promote both wound healing and scar attenuation.

Photoswitchable Microgels for Dynamic Macrophage Modulation.

Dynamic manipulation of supramolecular self-assembled structures is achieved irreversibly or under non-physiological conditions, thereby limiting their biomedical, environmental, and catalysis applicability. In this study, microgels composed of azobenzene derivatives stacked via π-cation and π-π interactions are developed that are electrostatically stabilized with Arg-Gly-Asp (RGD)-bearing anionic polymers. Lateral swelling of RGD-bearing microgels occurs via cis-azobenzene formation mediated by near-infrared-light-upconverted ultraviolet light, which disrupts intermolecular interactions on the visible-light-absorbing upconversion-nanoparticle-coated materials. Real-time imaging and molecular dynamics simulations demonstrate the deswelling of RGD-bearing microgels via visible-light-mediated trans-azobenzene formation. Near-infrared light can induce in situ swelling of RGD-bearing microgels to increase RGD availability and trigger release of loaded interleukin-4, which facilitates the adhesion structure assembly linked with pro-regenerative polarization of host macrophages. In contrast, visible light can induce deswelling of RGD-bearing microgels to decrease RGD availability that suppresses macrophage adhesion that yields pro-inflammatory polarization. These microgels exhibit high stability and non-toxicity. Versatile use of ligands and protein delivery can offer cytocompatible and photoswitchable manipulability of diverse host cells.

In situ microenvironment remodeling using a dual-responsive system: photodegradable hydrogels and gene activation by visible light.

A 3D microenvironment with dynamic cell-biomaterial interactions was developed using a dual-responsive system for in situ microenvironment remodeling and control of cellular function. A visible-light-responsive polymer was utilized to prepare a hydrogel with photodegradation properties, enabling in situ microenvironment remodeling. Additionally, a vascular endothelial growth factor (VEGF) gene activation unit that was responsive to the same wavelength of light was incorporated to support the potential application of the system in regenerative medicine. Following light exposure, the mechanical properties of the photodegradable hydrogel gradually deteriorated, and product analysis confirmed the degradation of the hydrogel, and thereby, 3D microenvironment remodeling. In situ microenvironment remodeling influenced stem cell proliferation and enlargement within the hydrogel. Furthermore, stem cells engineered to express light-activated VEGF and incorporated into the dual-responsive system were applied to wound healing and an ischemic hindlimb model, proving their potential application in regenerative medicine.

A Multimodal Approach to Huge Fibrous Dysplasia With Ocular Symptoms Using a Navigation System and Endoscope.

BACKGROUND: Fibrous dysplasia (FD) is a rare sporadic benign disease, which involves from single to several bones with unilateral distribution. Recently, image-based surgical navigation systems have played a significant role in surgical process on neurological and orthopedic operations. However, because an intraoral approach can visualize the field for maxillary surgery, there are few cases using endoscopes for excision of FD. Even though, a huge mass involving posterior side of maxillary sinus can be assisted with an endoscope to protect essential structures. To the best of our knowledge, this is the first report of plastic and reconstructive surgeons to perform the operation of a huge FD with both an endoscope and a navigation system. METHODS: Preoperative computed tomography scan and magnetic resonance imaging was performed for precise diagnosis and setting the navigation system (Medtronic Navigation, Louisville, CO). The main problem of the patient was exophthalmos and decreased visual acuity, the authors decided to remove the mass involving the intraorbital portion and sphenoidal portion. Moreover, the mass was extending to intracranium, cooperation with the department of neurosurgery and otolaryngology was planned. The tumor reached by the endoscope was resected as much as possible. During the excision of the sphenoidal portion by the head and neck surgeon of the department of otolaryngology, cerebrospinal fluid leakage was observed and repaired by the neurosurgeon. RESULTS: The exophthalmos measured by Hertel exophthalmometry was reduced only 1 mm, however, gross morphology of the patient was totally changed after the operation. Visual acuity of the right eye was improved from 0.3 to 0.9. The patient was followed up about 6 months and had a seizure event at 2 weeks after the surgery. Afterwards, the symptom has been well controlled by the medication. CONCLUSIONS: This multimodal approach offers a safe, rapid surgical aid in treating huge lesions involving orbital and intracranial area.

Cleavage-Responsive Biofactory T Cells Suppress Infectious Diseases-Associated Hypercytokinemia.

Severe infectious diseases, such as coronavirus disease 2019 (COVID-19), can induce hypercytokinemia and multiple organ failure. In spite of the growing demand for peptide therapeutics against infectious diseases, current small molecule-based strategies still require frequent administration due to limited half-life and enzymatic digestion in blood. To overcome this challenge, a strategy to continuously express multi-level therapeutic peptide drugs on the surface of immune cells, is established. Here, chimeric T cells stably expressing therapeutic peptides are presented for treatment of severe infectious diseases. Using lentiviral system, T cells are engineered to express multi-level therapeutic peptides with matrix metallopeptidases- (MMP-) and tumor necrosis factor alpha converting enzyme- (TACE-) responsive cleavage sites on the surface. The enzymatic cleavage releases γ-carboxyglutamic acid of protein C (PC-Gla) domain and thrombin receptor agonist peptide (TRAP), which activate endothelial protein C receptor (EPCR) and protease-activated receptor-1 (PAR-1), respectively. These chimeric T cells prevent vascular damage in tissue-engineered blood vessel and suppress hypercytokinemia and lung tissue damages in vivo, demonstrating promise for use of engineered T cells against sepsis and other infectious-related diseases.

Tissue extracellular matrix hydrogels as alternatives to Matrigel for culturing gastrointestinal organoids.

Matrigel, a mouse tumor extracellular matrix protein mixture, is an indispensable component of most organoid tissue culture. However, it has limited the utility of organoids for drug development and regenerative medicine due to its tumor-derived origin, batch-to-batch variation, high cost, and safety issues. Here, we demonstrate that gastrointestinal tissue-derived extracellular matrix hydrogels are suitable substitutes for Matrigel in gastrointestinal organoid culture. We found that the development and function of gastric or intestinal organoids grown in tissue extracellular matrix hydrogels are comparable or often superior to those in Matrigel. In addition, gastrointestinal extracellular matrix hydrogels enabled long-term subculture and transplantation of organoids by providing gastrointestinal tissue-mimetic microenvironments. Tissue-specific and age-related extracellular matrix profiles that affect organoid development were also elucidated through proteomic analysis. Together, our results suggest that extracellular matrix hydrogels derived from decellularized gastrointestinal tissues are effective alternatives to the current gold standard, Matrigel, and produce organoids suitable for gastrointestinal disease modeling, drug development, and tissue regeneration.

Precision targeting tumor cells using cancer-specific InDel mutations with CRISPR-Cas9.

An ideal cancer therapeutic strategy involves the selective killing of cancer cells without affecting the surrounding normal cells. However, researchers have failed to develop such methods for achieving selective cancer cell death because of shared features between cancerous and normal cells. In this study, we have developed a therapeutic strategy called the cancer-specific insertions-deletions (InDels) attacker (CINDELA) to selectively induce cancer cell death using the CRISPR-Cas system. CINDELA utilizes a previously unexplored idea of introducing CRISPR-mediated DNA double-strand breaks (DSBs) in a cancer-specific fashion to facilitate specific cell death. In particular, CINDELA targets multiple InDels with CRISPR-Cas9 to produce many DNA DSBs that result in cancer-specific cell death. As a proof of concept, we demonstrate here that CINDELA selectively kills human cancer cell lines, xenograft human tumors in mice, patient-derived glioblastoma, and lung patient-driven xenograft tumors without affecting healthy human cells or altering mouse growth.

Core Extirpation and Zygoma Reduction: A New Surgical Approach for Fibrous Dysplasia of Zygomaticomaxillary Region.

INTRODUCTION: In case of zygomaticomaxillary fibrous dysplasia (FD), surgical treatment is often required due to visual disturbance, exophthalmos, and also necessary for cosmetic reasons. However, it is not easy to determine the timing and method of operation. The objective of our study is to define a new surgical option, for the treatment of FD of zygomaticomaxillary area. MATERIALS AND METHODS: Five patients affected by FD of their zygomaticomaxillary area who underwent surgery with a core extirpation were included in this study. A retrospective chart review and pre- and post-operative analysis of computed tomography scan were performed. RESULTS: All patients underwent core extirpation surgery and zygoma reduction was combined in 2 patients. All patients showed the cessation of the increase of external size postoperatively and results of the operation were well maintained over the follow-up period of 1 year. CONCLUSIONS: In this article, we present our experiences in the management of FD using the core extirpation with or without zygoma reduction, focusing on surgical indication, techniques, and results. Although there are limitations due to selective operative indication, the procedure can be usefully performed to prevent external growth and avoid repetitive surgery.

Polycaprolactone Mesh for Asian Rhinoplasty: Outcomes and Complications of Composite Septal Extension Graft Compared to Mesh-Only Graft.

Despite the great demand of aesthetic rhinoplasty in Asian population, it is difficult to obtain the lasting ideal tip projection along with lengthening of the nose due to the small and weak nasal septum. The shortage of available septal cartilage to work with is another major obstacle. A retrospective study was conducted between January 2017 and December 2019 in Seoul, Korea. A total of 774 patients underwent septorhinoplasty using polycaprolactone (PCL) mesh for the cosmetic enhancement of the nasal tip and the projection. Comparisons of aesthetic outcomes, patients' satisfaction surveys, and complications were performed between PCL mesh-only group and composite PCL group. Of all the patients, 97.5% of the patients in composite PCL group were rated more than 3 scores in aesthetic outcomes, whereas 90.4% in mesh-only group (p-value = 0.0002). About 96.7% of the patients with composite PCL rated their satisfaction level as more than satisfied, whereas 94.3% in mesh-only group (p-value = 0.0365). Overall, there were 17 patients in composite PCL group who exhibited complications including decreased tip projection, deviated nasal tip, mesh infection, and mesh exposure. However, there were two patients who had mesh injection in mesh-only group. Septorhinoplasty with septal extension graft using composite PCL graft provides robust support to the aesthetically modified projection and the lengthened nose without obvious complications on the nasal tip. Such technique allows surgeons to overcome the nature of Asian nose that is weak and small, and also provides satisfaction to patients who desire ideal tip projections and dramatic changes.

Effects of a Catechol-Functionalized Hyaluronic Acid Patch Combined with Human Adipose-Derived Stem Cells in Diabetic Wound Healing.

INTRODUCTION: Chronic inflammation and impaired neovascularization play critical roles in delayed wound healing in diabetic patients. To overcome the limitations of current diabetic wound (DBW) management interventions, we investigated the effects of a catechol-functionalized hyaluronic acid (HA-CA) patch combined with adipose-derived mesenchymal stem cells (ADSCs) in DBW mouse models. METHODS: Diabetes in mice (C57BL/6, male) was induced by streptozotocin (50 mg/kg, >250 mg/dL). Mice were divided into four groups: control (DBW) group, ADSCs group, HA-CA group, and HA-CA + ADSCs group (n = 10 per group). Fluorescently labeled ADSCs (5 × 105 cells/100 µL) were transplanted into healthy tissues at the wound boundary or deposited at the HA-CA patch at the wound site. The wound area was visually examined. Collagen content, granulation tissue thickness and vascularity, cell apoptosis, and re-epithelialization were assessed. Angiogenesis was evaluated by immunohistochemistry, quantitative real-time polymerase chain reaction, and Western blot. RESULTS: DBW size was significantly smaller in the HA-CA + ADSCs group (8% ± 2%) compared with the control (16% ± 5%, p < 0.01) and ADSCs (24% ± 17%, p < 0.05) groups. In mice treated with HA-CA + ADSCs, the epidermis was regenerated, and skin thickness was restored. CD31 and von Willebrand factor-positive vessels were detected in mice treated with HA-CA + ADSCs. The mRNA and protein levels of VEGF, IGF-1, FGF-2, ANG-1, PIK, and AKT in the HA-CA + ADSCs group were the highest among all groups, although the Spred1 and ERK expression levels remained unchanged. CONCLUSIONS: The combination of HA-CA and ADSCs provided synergistic wound healing effects by maximizing paracrine signaling and angiogenesis via the PI3K/AKT pathway. Therefore, ADSC-loaded HA-CA might represent a novel strategy for the treatment of DBW.

Immunomodulatory Scaffolds Derived from Lymph Node Extracellular Matrices.

Immunomodulation in the local tissue microenvironment is pivotal for the determination of macrophage phenotypes and regulation of functions necessary for pro-healing effects. Herein, we demonstrate that a lymph node extracellular matrix (LNEM) prepared by the decellularization of lymph node tissues can mimic lymph node microenvironments for immunomodulation in two-dimensional (2D) and three-dimensional (3D) formats. The LNEM exhibits strengthened immunomodulatory effects in comparison to conventional collagen-based platforms. A 3D LNEM hydrogel is more effective than the 2D LNEM coating in inducing M2 macrophage polarization. The 3D LNEM induces macrophage elongation and enhances the M2-type marker expression and the secretion of anti-inflammatory cytokines. Additionally, the phagocytic function of macrophages is improved upon exposure to the intricate 3D LNEM environment. We demonstrate the reduced susceptibility of liver organoids to a hepatotoxic drug when co-cultured with macrophages in a 3D LNEM. This effect could be attributed to the enhanced anti-inflammatory functions and indicates its potential as a drug-testing platform that enables drug responses similar to those observed in vivo. Finally, the implantation of an LNEM hydrogel in a mouse volumetric muscle loss model facilitates the recruitment of host macrophages to the site of injury and enhances macrophage polarization toward the M2 phenotype for tissue healing in vivo. Therefore, 3D immune system-mimicking biomaterials could serve as useful platforms for tissue modeling and regenerative medicine development.