Polydopamine is the first adhesive polymer that can functionalize surfaces made of virtually all material chemistries. The material‐independent surface modification properties of polydopamine allow the functionalization of various types of medical and energy devices. However, the mechanism of dopamine polymerization has not yet been clearly demonstrated. Covalent oxidative polymerization via 5,6‐dihydroxyindole (DHI), which is similar to the mechanism for synthetic melanin synthesis, has been the clue. Here, it is reported that a physical, self‐assembled trimer of (dopamine)2/DHI exists in polydopamine, which has been known to be formed only by covalent polymerization. It is also found that the trimeric complex is tightly entrapped within polydopamine and barely escapes from the polydopamine complex. The result explains the previously reported in vitro and in vivo biocompatibility. The study reveals a different perspective of polydopamine formation, where it forms in part by the self‐assembly of dopamine and DHI, providing a new clue toward understanding the structures of catecholamines such as melanin.
Purpose: To assess the immunologic effects of dabrafenib and trametinib in vitro and to test whether trametinib potentiates or antagonizes the activity of immunomodulatory antibodies in vivo.Experimental Design: Immune effects of dabrafenib and trametinib were evaluated in human CD4 þ and CD8 þ T cells from healthy volunteers, a panel of human tumor cell lines, and in vivo using a CT26 mouse model.
Conjugation of mussel-inspired catechol groups to various polymer backbones results in materials suitable as silicon anode binders. The unique wetness-resistant adhesion provided by the catechol groups allows the silicon nanoparticle electrodes to maintain their structure throughout the repeated volume expansion and shrinkage during lithiation cycling, thus facilitating substantially improved specific capacities and cycle lives of lithium-ion batteries.
Capture and release: The material‐independent surface chemistry of a poly(norepinephrine) (pNE) which exhibits perfect smoothness at the nanometer scale is controlled by 3,4‐dihydroxybenzaldehyde‐norepinephrine (DHBA‐NE) conjugates. The pNE layer containing DHBA‐NE serves to store and release small therapeutics such as nitric oxide.
Pancreatic ductal adenocarcinoma (PDAC) is usually detected late in the disease process. Clinical work-up through imaging and tissue biopsies is often complex and expensive due to a paucity of reliable biomarkers. Here, we used an advanced multiplexed plasmonic assay to analyze circulating, tumor-derived extracellular vesicles (tEV) in over 100 clinical populations. Using EV based protein marker profiling, we identified a signature of 5 markers (PDACEV signature) for PDAC detection. In our prospective cohort, the accuracy for the PDACEV signature was 84% (95% confidence interval, CI: 69–93%), but only 63–72% for single marker screening. GPC1 alone had a sensitivity of 82% (CI: 60–95%) and a specificity of 52% (CI: 30–74%) while the PDACEV signature showed a sensitivity of 86% (CI: 65–97%) and a specificity of 81% (CI: 58–95%). We show that the PDACEV signature of tEV offered higher sensitivity, specificity, and accuracy than existing serum (CA 19-9) or single tEV marker analyses. This approach should enhance the diagnosis of pancreatic cancer.
Photocrosslinkable materials have been frequently used for constructing soft and biomimetic hydrogels for tissue engineering. Although, ultraviolet (UV) light is commonly used for photocrosslinking such materials, its use has been associated with several biosafety concerns such as DNA damage, accelerated aging of tissues, and cancer. Here we report an injectable visible light crosslinked gelatin-based hydrogel for myocardium regeneration. Mechanical characterization revealed that the compressive moduli of the engineered hydrogels could be tuned in the range of 5–56 kPa, by changing the concentrations of the co-initiator and co-monomer in the precursor formulation. In addition, the average pore sizes (26–103 μm) and swelling ratio (7–13%) were also shown to be tunable by varying the hydrogel formulation. In vitro studies showed that visible light crosslinked GelMA hydrogels supported the growth and function of primary cardiomyocytes (CMs). In addition, the engineered materials were shown to be biocompatible in vivo, and could be successfully delivered to the heart after myocardial infarction in an animal model to promote tissue healing. The developed visible light crosslinked hydrogel could be used for the repair of various soft tissues such as the myocardium, and for the treatment of cardiovascular diseases with enhanced therapeutic functionality.
Adhesives play an important role in industrial fields such as electronics, architectures, energy plantation, and others. However, adhesives used for medical purpose are rather under‐developed compared with those used in industry and consumer products. One key property required for medical adhesives is to maintain their adhesiveness in the presence of body fluid. Here, an entirely new class of medical adhesives called TAPE is reported; this is produced by intermolecular hydrogen bonding between a well‐known polyphenol compound, tannic acid, and poly(ethylene glycol). The preparation method of TAPE is extremely easy, forming a few liters at once by just the simple mixing of the two compounds without any further chemical synthetic procedures. TAPE shows a 250% increase in adhesion strength compared with fibrin glue, and the adhesion is well maintained in aqueous environments. It is demonstrated that TAPE is an effective hemostatic material and a biodegradable patch for detecting gastroesophageal reflux disease in vivo. Widespread use of TAPE is anticipated in various medical and pharmaceutical applications such as muco‐adhesives, drug depots, and others, because of its scalability, adhesion, and facile preparation.
Nature has developed materials that are integrated and effective at controlling their properties of adhesiveness and cohesiveness; the chemistry of these materials has been optimized during evolution. For example, a catechol moiety found in the adhesive proteins of marine mussels regulates its properties between adhesion and cohesion, rapidly adapting to environmental conditions. However, in synthetic materials chemistry, introduced chemical moieties are usually monofunctional, either being adhesive or cohesive; typically, this is not effective compared to natural materials. Herein, it is demonstrated that hyaluronic acid‐catechol (HA‐catechol) conjugates can exhibit either adhesiveness, functionalizing the surface of materials, or cohesiveness, building 3D hydrogels. Up to now, catechol‐conjugated polymers have shown to be useful in one of these two functions. The usefulness of the polymer in stem cell engineering is demonstrated. A platform for neural stem cell culture may be prepared, utilizing the adhesive property of HA‐catechol, and hydrogels are fabricated to encapsulate the neural stem cells, utilizing the cohesive property of the HA conjugate. Moreover, the HA‐catechol hydrogels are highly neural stem cell compatible, showing better viability compared to existing methods based on HA hydrogels.
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