ACS Applied Bio Materials最新文献

Sulfur mustard (SM), a blister agent and toxic chemical warfare compound, leads to injuries in the skin, eyes, and lungs, with early diagnosis being difficult because of its incubation period. Developing scavengers for sulfur mustard (SM) and its simulant, 2-chloroethylsulfide (CEES), is essential due to the severe and long-lasting toxic effects these compounds have on the human body. Existing scavengers like cysteine, sodium hydrosulfide (NaHS), and sodium thiosulfate cannot cross the blood-brain barrier (BBB), rendering them ineffective for detoxifying SM in the brain and highlighting the need for lipophilic scavengers. In this study, an N-salicylaldehyde naphthyl thiourea probe (NCrHT) was developed for detecting SM simulant CEES and its in vivo and in vitro imaging capabilities were evaluated. Additionally, the detoxification potential of scavengers was tested under similar conditions, and we introduced N-acetyl cysteine, which is lipophilic in nature, as an effective scavenger for detoxifying CEES in the zebrafish brain.

Expanded polystyrene (EPS) remains a popular packaging material despite environmental concerns such as pollution, difficulty to recycle, and toxicity to wildlife. The goal of this study is to evaluate the potential of an ecofriendly alternative to traditional EPS composed of a mycelium biocomposite grown from agricultural waste. In this material, the mycelium spores are incorporated into cellulosic waste, resulting in a structurally sound biocomposite completely enveloped by mycelium fibers. One of the main criteria for shipping applications is the ability of a material to withstand extreme weather conditions. Accordingly, this study focused on evaluating a commercially available mycelium material before and after exposure to various weathering conditions, including high and low temperatures at different humidity levels. Fourier transform infrared spectroscopy (FTIR) was performed to examine any transformations in the mycelium structure and composition, whereas scanning electron microscopy (SEM) was used to reveal any changes in the morphology. Similarly, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analyses were conducted to evaluate the thermal behavior, whereas mechanical properties were measured by using shore hardness and Izod Impact testing. Although some irreversible changes were observed due to the exposure to high temperatures, the material exhibited good thermal stability and impact resistance. FTIR analysis demonstrated small changes in the biocomposite structure and protein rearrangement as a result of weathering, whereas SEM revealed some cracking in the cellulose substrate. A combination of low temperatures and humidity resulted in significant moisture absorption, as indicated by TGA and DSC. This in turn decreased the hardness of the fibers by nearly 2-fold; however, the impact strength of the entire biocomposite remained unchanged. Overall, these results provide important insight into the structure-property relationships of mycelium-based materials.

Plants as living organisms, as well as their material-structural components and physiological processes, offer promising elements for developing more sustainable technologies. Previously, we demonstrated that plants could acquire electronic functionality, as their enzymatic activity catalyzes the in vivo polymerization of water-soluble conjugated oligomers. We then leveraged plant-integrated conductors to develop biohybrid energy storage devices and circuits. Here, we extend the concept of plant biohybrids to develop plant-based energy-harvesting devices. We demonstrate plant biohybrids with modified roots that can convert common root exudates, such as glucose, to electricity. To do so, we developed a simple one-step approach to convert living roots to glucose-sensitive electrodes by dipping the root in a solution of the conjugated trimer ETE-S and the enzyme glucose dehydrogenase flavin adenine dinucleotide. The biohybrid device responds to glucose concentrations down to 100 μM while it saturates at 100 mM. The performance of our approach was compared with a classic mediator-based glucose biosensor functionalization method. While the latter method increases the stability of the sensor, it results in less sensitivity and damages the root structure. Finally, we show that glucose oxidation can be combined with the volumetric capacitance of p(ETE-S)-forming devices that generate current in the presence of glucose and store it in the same biohybrid root electrodes. The plant biohybrid devices open a pathway to biologically integrated technology that finds application in low-power devices, for example, sensors for agriculture or the environment.

Exosomes are small extracellular vesicles (EVs) constituting fully biological, cell-derived nanovesicles with great potential in cell-to-cell communication and drug delivery applications. The current gold standard for EV labeling and tracking is represented by fluorescent lipophilic dyes which, however, importantly lack selectivity, due to their unconditional affinity for lipids. Herein, an alternative EV fluorescent labeling approach is in-depth evaluated, by taking advantage of green fluorescent protein (GFP) farnesylation (GFP-f), a post-translational modification to directly anchor GFP to the EV membrane. The performance of GFP-f is analyzed, in terms of selectivity and efficiency, in several typical EV experimental setups such as delivery in recipient cells, surface engineering, and cargo loading. First, the capability of GFP and GFP-f to label exosomes was compared, showing significantly higher GFP protein levels and fluorescence intensity in GFP-f- than in GFP-labeled exosomes, highlighting the advantage of directly anchoring the GFP to the EV cell membrane. Then, the GFP-f tag was further compared to Vybrant DiD lipophilic dye labeling in exosome uptake studies, by capturing EV intracellular fluorescence in a time- and concentration-dependent manner. The internalization assay revealed a particular ability of GFP-f to monitor the uptake of tagged exosomes into recipient cells, with a significant peak of intensity reached 12 h after administration by GFP-f but not Vybrant-labeled EVs. Finally, the GFP-f labeling capability was challenged in the presence of a surface modification of exosomes and after transfection for siRNA loading. Results showed that both procedures can influence GFP-f performance compared to naïve GFP-f exosomes, although fluorescence is importantly maintained in both cases. Overall, these data provide direct insight into the advantages and limitations of GFP-f as a tagging protein for selectively and accurately tracking the exosome route from isolation to uptake in recipient cells, also in the context of EV bioengineering applications.

Pancreatic ductal adenocarcinoma (PDAC) is a cancer of the epithelia comprising the ductal network of the pancreas. During disease progression, PDAC tumors recruit fibroblasts that promote fibrosis, increasing local tissue stiffness and subjecting epithelial cells to increased compressive forces. Previous in vitro studies have documented cytoskeletal and nuclear adaptation following compressive stresses in two-dimensional (2D) and three-dimensional (3D) environments. However, a comparison of the responses of normal and tumor-derived ductal epithelia to physiologically relevant confinement remains underexplored, especially in 3D organoids. Here we control confinement with an engineered 3D microenvironment composed of Matrigel mixed with a low yield stress granular microgel. Normal and tumor-derived murine pancreas organoids (normal and tumor) were cultured for 48 h within this composite 3D environment or in pure Matrigel to investigate the effects of confinement on morphogenesis and lumen expansion. In confinement, tumor organoids (mT) formed a lumen that expanded rapidly, whereas normal organoids (mN) expanded more slowly. Moreover, a majority of normal organoids in more-confined conditions exhibited an inverted apicobasal polarity compared to those in less-confined conditions. Tumor organoids exhibited a collective "pulsing" behavior that increased in confinement. These pulses generated forces sufficient to locally overcome the yield stress of the microgels in the direction of organoid expansion. Normal organoids more commonly exhibit unidirectional rotation. Our in vitro microgel confinement platform enabled the discovery of two distinct modes of collective force generation in organoids that may shed light on the mutual interactions between tumors and the microenvironment. These insights into in vitro dynamics may deepen our understanding of how the confinement of healthy cells within a fibrotic tumor niche disrupts tissue organization and function in vivo.

A zwitterionic, stimuli-responsive liposomal system was meticulously designed for the precise and controlled delivery of curcumin, leveraging enzyme-specific and hyperthermic stimuli to enhance therapeutic outcomes. This platform is specifically engineered to release curcumin in response to phospholipase A2, an enzyme that degrades phospholipids, enabling highly targeted and site-specific drug release. Mild hyperthermia (40 °C) further enhances membrane permeability and activates thermosensitive carriers, optimizing drug delivery. Curcumin encapsulation is facilitated through a combination of zwitterionic and electrostatic interactions, significantly improving both loading capacity and encapsulation efficiency. A design of experiments (DoE) approach was employed to systematically optimize lipid-to-cholesterol ratios and formulation conditions. The liposomal system was thoroughly characterized using dynamic light scattering, zeta potential measurements, and transmission electron microscopy, ensuring stability and structural integrity. Notably, this system effectively encapsulates hydrophobic curcumin while maintaining particle size and bioactivity. In vitro studies revealed robust antioxidant and anti-ROS activities, alongside excellent biocompatibility, with no cytotoxicity observed at concentrations up to 2000 μg/mL. Furthermore, the zwitterionic liposomes enhanced M2 macrophage polarization and reduced oxidative stress. This advanced platform offers a promising, biocompatible solution for targeted curcumin delivery.

This study implemented the application of microcomputed tomography (micro-CT) as a characterization technique for the study and investigation of the microstructure of 3D scaffold structures produced via three-dimensional bioprinting (3DBP). The study focused on the preparation, characterization, and cytotoxicity analysis of gold nanoparticles (Au-NPs) incorporated into 3DBP hydrogels for micro-CT evaluation. The Au-NPs were characterized by using various techniques, including UV-vis spectrometry, dynamic light scattering (DLS), zeta potential measurement, and transmission electron microscopy (TEM). The characterization results confirmed the successful coating of the Au-NPs with 2 kDa methoxy-PEG and revealed their spherical shape with a mean core diameter of 66 nm. Cytotoxicity analysis using live-dead fluorescent microscopy indicated that all tested Au-NP solutions were nontoxic to AC16 cardiomyocytes in both 2D and 3D culture conditions. Scanning electron microscopy (SEM) showed distinguishable differences in image contrast and intensity between samples with and without Au-NPs, with high concentrations of Au-NPs displaying nanoparticle aggregates. Micro-CT imaging demonstrated that scaffolds containing Au-NPs depicted enhanced imaging resolution and quality, allowing for visualization of the microstructure. The 3D reconstruction of scaffold structures from micro-CT imaging using Dragonfly software further supported the improved visualization. Mechanical analysis revealed that the addition of Au-NPs enhanced the mechanical properties of acellular scaffolds, including their elastic moduli and complex viscosity, but the presence of cells led to biodegradation and reduced mechanical strength. These findings highlight the successful preparation and characterization of Au-NPs, their nontoxic nature in both 2D and 3D culture conditions, their influence on imaging quality, and the impact on the mechanical properties of 3D-printed hydrogels. These results contribute to the development of functional and biocompatible materials for tissue engineering and regenerative medicine applications.

Most ovarian carcinoma (OvCa) patients present with advanced disease at the time of diagnosis. Malignant, metastatic OvCa is invasive and has poor prognosis, exposing the need for improved therapeutic targeting. High CD47 (OvCa) and SIRPα (macrophage) expression has been linked to decreased survival, making this interaction a significant target for therapeutic discovery. Even so, previous attempts have fallen short, limited by CD47 antibody specificity and efficacy. Macrophages are an important component of the OvCa tumor microenvironment and are manipulated to aid in cancer progression via CD47-SIRPα signaling. Thus, we have leveraged lipid-based nanoparticles (LNPs) to design a therapy uniquely situated to home to phagocytic macrophages expressing the SIRPα protein in metastatic OvCa. CD47-SIRPα presence was evaluated in patient histological sections using immunohistochemistry. 3D tumor spheroids generated on a hanging drop array with OVCAR3 high-grade serous OvCa and THP-1-derived macrophages created a representative model of cellular interactions involved in metastatic OvCa. Microfluidic techniques were employed to generate LNPs encapsulating SIRPα siRNA (siSIRPα) to affect the CD47-SIRPα signaling between the OvCa and macrophages. siSIRPα LNPs were characterized for optimal size, charge, and encapsulation efficiency. Uptake of the siSIRPα LNPs by macrophages was assessed by Incucyte. Following 48 h of 25 nM siSIRPα treatment, OvCa/macrophage heterospheroids were evaluated for SIRPα knockdown, platinum chemoresistance, and invasiveness. OvCa patient tumors and in vitro heterospheroids expressed CD47 and SIRPα. Macrophages in OvCa spheroids increased carboplatin resistance and invasion, indicating a more malignant phenotype. We observed successful LNP uptake by macrophages causing significant reduction in SIRPα gene and protein expressions and subsequent reversal of pro-tumoral alternative activation. Disrupting CD47-SIRPα interactions resulted in sensitizing OvCa/macrophage heterospheroids to platinum chemotherapy and reversal of cellular invasion outside of heterospheroids. Ultimately, our results strongly indicate the potential of using LNP-based nanoimmunotherapy to reduce malignant progression of ovarian cancer.

3D bioprinting stands out as one of the most promising innovations in the field of high technologies for personalized biomedicine, enabling the fabrication of biomaterial-based scaffolds designed to repair, restore, or regenerate tissues and organs in the body. Among the various materials used as inks, hydrogels play a critical role due to their unique characteristics, including excellent biocompatibility, adjustable mechanical properties, and high solvent retention. This versatility makes them ideal for various applications such as biomedical devices, drug delivery, or flexible electronics. Although chitosan is a promising material for such applications, when used alone, it does not possess the necessary strength and stiffness for creating high-resolution 3D bioprinted structures. In this study, we propose a combined method for the fabrication of self-supporting 3D printed objects with an ink made of chitosan and tamarind gum. Our approach involves two key techniques. The first one is a controlled evaporation of the solvent, aiming to increase the concentration of the components of the ink. The second one relies on printing in a gelling bath composed of sodium hydroxide and ethanol, allowing for improved printability and long-term stability of the scaffolds. The results obtained revealed the possibility of modulating the concentration of the components based on the heating time. The latter positively influences not only the ink printability but also the properties of the resulting scaffolds such as their biodegradability and mechanical properties.

For developing a successful cancer therapeutic modality, the early precise detection of cancer cells in patient biopsies in oral squamous cell carcinoma (OSCC) is crucial. This could help researchers create new diagnostic and therapeutic tools and assist clinicians in recommending more effective treatment plans and improving patient survival. We have developed an SMPD, cyclooxygenase-2 (COX-2) targeting pH-activable fluorophore named CNP, combining a potent COX-2 inhibitor, celecoxib, linked to a naphthalimide fluorophore with an acidic microenvironment-responsive piperazine moiety for specific optical imaging of OSCC in cells and patient tissues. Compared to reference probe RNP lacking celecoxib, CNP selectively enters the COX-2 overexpressing oral cancer cells. Its acidity-responsive imaging response enhances selectivity over cancers with lower COX-2 expression levels and normal cells. Further, CNP is demonstrated in imaging OSCC cells in patient-derived biopsies. Thus, multifunctional CNP shows potential in exploring more reagents for fluorescence-based detection of OSCC cells in patient tissues with translational applications.