Adhesive and Conductive Fibrous Hydrogel Bandages for Effective Peripheral Nerve Regeneration.

Peripheral nerve injury is a common disease resulting in reversible and irreversible impairments of motor and sensory functions. In addition to conventional surgical interventions such as nerve grafting and neurorrhaphy, nerve guidance conduits are used to effectively support axonal growth without unexpected neuroma formation. However, there are still challenges to secure tissue-mimetic mechanical and electrophysiological properties of the conduit materials.

Polymeric DNase-I nanozymes targeting neutrophil extracellular traps for the treatment of bowel inflammation.

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a family of chronic disorders along the gastrointestinal tract. Because of its idiopathic nature, IBD does not have a fundamental cure; current available therapies for IBD are limited to prolonged doses of immunomodulatory agents. While these treatments may reduce inflammation, limited therapeutic efficacy, inconsistency across patients, and adverse side effects from aggressive medications remain as major drawbacks.

Stretchable Gold Nanomembrane Electrode with Ionic Hydrogel Skin-Adhesive Properties.

Skin has a dynamic surface and offers essential information through biological signals originating from internal organs, blood vessels, and muscles. Soft and stretchable bioelectronics can be used in wearable machines for long-term stability and to continuously obtain distinct bio-signals in conjunction with repeated expansion and contraction with physical activities. While monitoring bio-signals, the electrode and skin must be firmly attached for high signal quality.

Ferritin Nanoshuttle for Long-Lasting Self-Healing of Phenolic Hydrogels.

Herein, we highlight a novel finding that ferritin can play a crucial role in the "self-healing lifetime" of soft phenolic materials. Ferritin interacts with a catechol-functionalized polymer to form a self-healable and adhesive hydrogel bidirectionally by providing and retrieving Fe. As a result of its unique role as a nanoshuttle to store and release iron, ferritin significantly increases the self-healing lifetime of the hydrogel compared with that afforded by catechol-Fe coordination through direct Fe addition without ferritin.

Biomaterials as therapeutic drug carriers for inflammatory bowel disease treatment.

Inflammatory bowel diseases (IBDs) are idiopathic gastrointestinal inflammatory disorders featuring chronic intestinal inflammation. Although IBDs are increasingly becoming globally prevalent, the exact etiology of IBD remains obscure. Recently, the ability of various drugs for mucosal healing such as corticosteroids, antibiotics, and immunosuppressants has been proven.

Engineering of Immune Microenvironment for Enhanced Tissue Remodeling.

The capability to restore the structure and function of tissues damaged by fatal diseases and trauma is essential for living organisms. Various tissue engineering approaches have been applied in lesions to enhance tissue regeneration after injuries and diseases in living organisms. However, unforeseen immune reactions by the treatments interfere with successful healing and reduce the therapeutic efficacy of the strategies.

Microfluidic device with brain extracellular matrix promotes structural and functional maturation of human brain organoids.

Brain organoids derived from human pluripotent stem cells provide a highly valuable in vitro model to recapitulate human brain development and neurological diseases. However, the current systems for brain organoid culture require further improvement for the reliable production of high-quality organoids. Here, we demonstrate two engineering elements to improve human brain organoid culture, (1) a human brain extracellular matrix to provide brain-specific cues and (2) a microfluidic device with periodic flow to improve the survival and reduce the variability of organoids.

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.

Gastrointestinal synthetic epithelial linings.

Epithelial tissues line the organs of the body, providing an initial protective barrier as well as a surface for nutrient and drug absorption. Here, we identified enzymatic components present in the gastrointestinal epithelium that can serve as selective means for tissue-directed polymerization. We focused on the small intestine, given its role in drug and nutrient absorption and identified catalase as an essential enzyme with the potential to catalyze polymerization and growth of synthetic biomaterial layers.

Three-dimensional brain-like microenvironments facilitate the direct reprogramming of fibroblasts into therapeutic neurons.

Biophysical cues can improve the direct reprogramming of fibroblasts into neurons that can be used for therapeutic purposes. However, the effects of a three-dimensional (3D) environment on direct neuronal reprogramming remain unexplored. Here, we show that brain extracellular matrix (BEM) decellularized from human brain tissue facilitates the plasmid-transfection-based direct conversion of primary mouse embryonic fibroblasts into induced neuronal (iN) cells.

Decellularized Tissue Matrix for Stem Cell and Tissue Engineering.

Decellularization is a technique to remove cellular components from native tissues, which could reduce immune reactions to the scaffolds. Decellularized matrices are valuable for tissue engineering, as they preserve tissue-specific structural, mechanical, and biochemical microenvironments, while promoting cellular engraftment and functions in the matrix. So far, various tissues have been decellularized by combinations of mechanical, chemical, and enzymatic processes and utilized in preparing bioscaffolds to provide tissue-specific environments for various cell types, including primary cells, progenitor cells, and stem cells.

Ferritin nanoparticles for improved self-renewal and differentiation of human neural stem cells.

Background: Biomaterials that promote the self-renewal ability and differentiation capacity of neural stem cells (NSCs) are desirable for improving stem cell therapy to treat neurodegenerative diseases. Incorporation of micro- and nanoparticles into stem cell culture has gained great attention for the control of stem cell behaviors, including proliferation and differentiation.

Method: In this study, ferritin, an iron-containing natural protein nanoparticle, was applied as a biomaterial to improve the self-renewal and differentiation of NSCs and neural progenitor cells (NPCs).

Highly durable and biocompatible periodical Si/DLC nanocomposite coatings.

Functional nanocomposite coatings comprised of periodically stacked nanolayers of diamond-like carbon (DLC) and amorphous silicon were developed for biomedical applications. The periodical nanocomposite structure provided high surface durability while silicon aided in reducing the residual stress. The structural, mechanical, tribological, and biomedical properties of the Si/DLC coatings deposited by magnetron sputtering were investigated systematically.

Single-Droplet Multiplex Bioassay on a Robust and Stretchable Extreme Wetting Substrate through Vacuum-Based Droplet Manipulation.

Herein, a droplet manipulation system with a superamphiphobic (SPO)-superamphiphilic (SPI) patterned polydimethylsiloxane (PDMS) substrate is developed for a multiplex bioassay from single-droplet samples. The SPO substrate is fabricated by sequential spraying of adhesive and fluorinated silica nanoparticles onto a PDMS substrate. It is subsequently subjected to oxygen plasma with a patterned mask to form SPI patterns.

Bio-artificial tongue with tongue extracellular matrix and primary taste cells.

Artificial taste devices for tastant sensing and taste information standardization are attracting increasing attention with the exponential growth of the food and beverage industries. Despite recent developments in artificial taste sensors incorporating polymers, lipid membranes, and synthetic vesicles, current devices have limited functionality and sensitivity, and are complex to manufacture. Moreover, such synthetic systems cannot simulate the taste signal transmissions that are critical for complicated taste perception.

Role of Pyridoxal 5'-Phosphate at the Titanium Implant Interface In Vivo: Increased Hemophilicity, Inactive Platelet Adhesion, and Osteointegration.

Titanium is the most biocompatible inorganic biomaterial with a long history of use in orthopedic and dental implants. However, promoting rapid and effective bone formation and integration onto etched, rough TiO surfaces has been a challenging topic. Here, 21 commercially available molecules are examined that met the following criteria: (1) contain phosphonic acid for stable immobilization onto TiO surfaces and (2) have a molecular weight less than 500 Da for negligible coating thickness.

Galactosylated Lipidoid Nanoparticles for Delivery of Small Interfering RNA to Inhibit Hepatitis C Viral Replication In Vivo.

Small interfering RNA (siRNA) delivery can provide an effective therapy for treating viral diseases by silencing genes involved in viral replication. In this study, a liver-targeting formulation of lipidoid nanoparticle for delivery of siRNA that targets protein kinase C-related kinase 2 (PRK2) to inhibit hepatitis C virus (HCV) replication is reported. The most effective, minimally cytotoxic lipidoid for siRNA delivery to hepatic cells is identified from a small library of alkyl epoxide-polyamine conjugates.

Protective effect of fermented Cyclopia intermedia against UVB-induced damage in HaCaT human keratinocytes.

Background: The fermented leaves and stems of Cyclopia intermedia are used to brew honeybush tea, a herbal tea indigenous to South Africa. The aim of this study was to evaluate the protective effect of fermented honeybush extracts (FH ex) and scale-up fermented honeybush extracts (SFH ex) against ultraviolet B (UVB)-induced damage in HaCaT keratinocytes. To this end, we examined UVB-induced cell viability, antioxidant enzymes, and inflammatory mediators in HaCaT cells.

Triboelectric Nanogenerator Accelerates Highly Efficient Nonviral Direct Conversion and In Vivo Reprogramming of Fibroblasts to Functional Neuronal Cells.

Triboelectric nanogenerators (TENGs) can be an effective cell reprogramming platform for producing functional neuronal cells for therapeutic applications. Triboelectric stimulation accelerates nonviral direct conversion of functional induced neuronal cells from fibroblasts, increases the conversion efficiency, and induces highly matured neuronal phenotypes with improved electrophysiological functionalities. TENG devices may also be used for biomedical in vivo reprogramming.

Path-programmable water droplet manipulations on an adhesion controlled superhydrophobic surface.

Here, we developed a novel and facile method to control the local water adhesion force of a thin and stretchable superhydrophobic polydimethylsiloxane (PDMS) substrate with micro-pillar arrays that allows the individual manipulation of droplet motions including moving, merging and mixing. When a vacuum pressure was applied below the PDMS substrate, a local dimple structure was formed and the water adhesion force of structure was significantly changed owing to the dynamically varied pillar density. With the help of the lowered water adhesion force and the slope angle of the formed dimple structure, the motion of individual water droplets could be precisely controlled, which facilitated the creation of a droplet-based microfluidic platform capable of a programmable manipulation of droplets.