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. A three-dimensional culture modified with brain extracellular matrix significantly enhanced neurogenesis in developing brain organoids from human induced pluripotent stem cells. Cortical layer development, volumetric augmentation, and electrophysiological function of human brain organoids were further improved in a reproducible manner by dynamic culture in microfluidic chamber devices. Our engineering concept of reconstituting brain-mimetic microenvironments facilitates the development of a reliable culture platform for brain organoids, enabling effective modeling and drug development for human brain diseases.
Skeletal muscle has an inherent capacity for spontaneous regeneration. However, recovery after severe injuries such as volumetric muscle loss (VML) is limited. There is therefore a need to develop ...interventions to induce functional skeletal muscle restoration. One suggested approach includes tissue‐engineered muscle constructs. Tissue‐engineering treatments have so far been impeded by the lack of reliable cell sources and the challenges in engineering of suitable tissue scaffolds. To address these challenges, muscle extracellular matrix (MEM) and induced skeletal myogenic progenitor cells (iMPCs) are integrated within thermally drawn fiber based microchannel scaffolds. The microchannel fibers decorated with MEM enhance differentiation and maturation of iMPCs. Furthermore, engraftment of these bioengineered hybrid muscle constructs induce de novo muscle regeneration accompanied with microvessel and neuromuscular junction formation in a VML mouse model, ultimately leading to functional recovery of muscle activity.
A bioengineered skeletal muscle construct is generated by culturing induced skeletal myogenic progenitor cells in a thermally drawn polycaprolactone porous fiber scaffold modified with decellularized muscle extracellular matrix. The hybrid composite fiber shows favorable mechanical and biochemical signals for muscle reprogramming and maturation. The bioengineered muscle construct repairs volumetric muscle loss injury via de novo muscle regeneration and functional restoration.
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.
Exploitation of unique biochemical and biophysical properties of marine organisms has led to the development of functional biomaterials for various biomedical applications. Recently, ascidians have ...received great attention, owing to their extraordinary properties such as strong underwater adhesion and rapid self‐regeneration. Specific polypeptides containing 3,4,5‐trihydroxyphenylalanine (TOPA) in the blood cells of ascidians are associated with such intrinsic properties generated through complex oxidative processes. In this study, a bioinspired hydrogel platform is developed, demonstrating versatile applicability for tissue engineering and drug delivery, by conjugating pyrogallol (PG) moiety resembling ascidian TOPA to hyaluronic acid (HA). The HA–PG conjugate can be rapidly crosslinked by dual modes of oxidative mechanisms using an oxidant or pH control, resulting in hydrogels with different mechanical and physical characteristics. The versatile utility of HA–PG hydrogels formed via different crosslinking mechanisms is tested for different biomedical platforms, including microparticles for sustained drug delivery and tissue adhesive for noninvasive cell transplantation. With extraordinarily fast and different routes of PG oxidation, ascidian‐inspired HA–PG hydrogel system may provide a promising biomaterial platform for a wide range of biomedical applications.
Ascidian‐inspired, fast‐forming hyaluronic acid (HA) hydrogel systems are developed for versatile biomedical applications by dual modes of pyrogallol (PG)‐based oxidative crosslinking chemistry. HA–PG hydrogels prepared by oxidant or pH control exhibit different physical, mechanical, and degradation properties, allowing differential applications, i.e., either microparticles or tissue adhesives. Each HA–PG format is successfully tested for growth factor delivery for therapeutic angiogenesis and noninvasive cell therapy, respectively.
Microbeads have been utilized as efficient cell culture carriers and injectable scaffolds for cell transplantation. However, various polymers currently used to generate microbeads have limited ...applicability due to loss of biological functions and tissue‐specific effects. Here, a tissue bead platform is reported that can provide a tissue‐specific microenvironment to facilitate cell culture and potentiate cell therapy. Using a flow‐focusing microfluidic device, uniform‐sized tissue microbeads are fabricated with extracellular matrix (ECM) from various decellularized tissues. The tissue microbeads are tested for tissue‐specific encapsulation of induced hepatic (iHep), induced cardiac (iCar), and induced myogenic (iMyo) cells, which are directly reprogrammed from mouse primary fibroblasts. Tissue‐specific microbeads significantly enhanced the viability, lineage‐specific maturation, and functionality of each type of reprogrammed cell, as compared to functionality when using conventional microbeads from a single ECM component (collagen). Finally, tissue microbeads are confirmed to mediate the successful in vivo engraftment of reprogrammed cells (iHep and iMyo) after transplantation, potentiating cell therapy and promoting functional tissue regeneration in tissue defective animal models. The study suggests that the use of a decellularized tissue matrix combined with a microfluidic technique can be employed to produce tissue‐specific ECM microbeads with increased versatility and efficacy for reprogrammed cell‐based therapy.
“Tissue Beads”, a decellularized tissue‐derived microbead platform, is established via microfluidic fabrication for tissue‐specific cell culture and effective cell therapy. Tissue beads with a tissue‐specific extracellular matrix significantly improve viability, differentiation, and function of reprogrammed cells of different lineages. Moreover, tissue beads successfully mediate engraftment of transplanted reprogrammed cells and tissue regeneration for functional recovery in large tissue defects.
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► Salinomycin triggers caspase-dependent apoptosis by elevating the intracellular ROS level. ► Dissipation of MMP generated by elevated ROS is linked to the salinomycin-mediated cell ...death. ► The antioxidant
N-acetylcysteine prevented the escalation of oxidative stress by salinomycin. ► Salinomycin holds potential for inhibiting progression of therapy resistant prostate cancer.
The anticancer activity of salinomycin has evoked excitement due to its recent identification as a selective inhibitor of breast cancer stem cells (CSCs) and its ability to reduce tumor growth and metastasis
in vivo. In prostate cancer, similar to other cancer types, CSCs and/or progenitor cancer cells are believed to drive tumor recurrence and tumor growth. Thus salinomycin can potentially interfere with the end-stage progression of hormone-indifferent and chemotherapy-resistant prostate cancer. Androgen-responsive (LNCaP) and androgen-refractive (PC-3, DU-145) human prostate cancer cells showed dose- and time-dependent reduced viability upon salinomycin treatment; non-malignant RWPE-1 prostate cells were relatively less sensitive to drug-induced lethality. Salinomycin triggered apoptosis of PC-3 cells by elevating the intracellular ROS level, which was accompanied by decreased mitochondrial membrane potential, translocation of Bax protein to mitochondria, cytochrome
c release to the cytoplasm, activation of the caspase-3 and cleavage of PARP-1, a caspase-3 substrate. Expression of the survival protein Bcl-2 declined. Pretreatment of PC-3 cells with the antioxidant
N-acetylcysteine prevented escalation of oxidative stress, dissipation of the membrane polarity of mitochondria and changes in downstream molecular events. These results are the first to link elevated oxidative stress and mitochondrial membrane depolarization to salinomycin-mediated apoptosis of prostate cancer cells.
Tissue engineering of skeletal muscle has been proposed as a potential regenerative treatment for extensive muscle damage. In this regard, the highly organized structure of skeletal muscles makes the ...alignment of cells especially indispensable in muscle tissue engineering. However, achieving the desired alignment continues to prove challenging, particularly in 3D engineered tissue constructs. In this study, a biomimetic approach for the generation of functional skeletal muscle fascicle‐like tissues by recapitulating 3D muscle‐like cellular and extracellular organization, is demonstrated. Anisotropic 3D alignment of muscle extracellular matrix (MEM) nanofibrils capable of providing a pro‐myogenic microenvironment by regulating the kinetics of fibrillogenesis in a stretchable elastomeric chip, is achieved. Reprogrammed muscle progenitor cells develop myofibers along the aligned MEM nanofibrils in a 3D configuration, culminating in the structural and functional maturation of skeletal muscle. The resultant 3D muscle fascicle‐like constructs support de novo muscle regeneration and induce functional restoration of injured muscles in animal models inflicted with volumetric muscle loss and congenital muscular dystrophy. This study not only highlights the fundamental roles of the muscle–mimetic structural guidance cues for 3D muscle tissue engineering, but also unveils the clinical potential of artificial muscle constructs in regenerative medicine.
The highly organized structure of skeletal muscle is recapitulated by anisotropic 3D alignment of muscle extracellular matrix (MEM) nanofibrils by regulating the kinetics of fibrillogenesis in a stretchable elastomeric chip. Reprogrammed muscle progenitor cells develop myofibers along the aligned MEM nanofibrils, culminating in the structural and functional maturation of skeletal muscle for treating volumetric muscle loss and dystrophic muscle disorders.
The neurovascular unit, which consists of vascular cells surrounded by astrocytic end-feet and neurons, controls cerebral blood flow and the permeability of the blood-brain barrier (BBB) to maintain ...homeostasis in the neuronal milieu. Studying how some pathogens and drugs can penetrate the human BBB and disrupt neuronal homeostasis requires in vitro microphysiological models of the neurovascular unit. Here we show that the neurotropism of Cryptococcus neoformans-the most common pathogen causing fungal meningitis-and its ability to penetrate the BBB can be modelled by the co-culture of human neural stem cells, brain microvascular endothelial cells and brain vascular pericytes in a human-neurovascular-unit-on-a-chip maintained by a stepwise gravity-driven unidirectional flow and recapitulating the structural and functional features of the BBB. We found that the pathogen forms clusters of cells that penetrate the BBB without altering tight junctions, suggesting a transcytosis-mediated mechanism. The neurovascular-unit-on-a-chip may facilitate the study of the mechanisms of brain infection by pathogens, and the development of drugs for a range of brain diseases.
Stress-related symptoms are a global concern, impacting millions of individuals, yet effective and safe treatments remain scarce. Although multiple studies have highlighted the stress- alleviating ...properties of saffron extract, the underlying mechanisms remain unclear. This study employs the unpredictable chronic mild stress (CMS) animal model to investigate the impact of a standardized saffron extract, Affron
(AFN), on hypothalamic-pituitary-adrenal (HPA) axis regulation and neuroplasticity in Wistar rats following repeated oral administration. The research evaluates AFN's effects on various stress-related parameters, including hypothalamic gene expression, stress hormone levels, and the sucrose preference test. In animals subjected to continuous unpredictable CMS, repetitive administration of AFN at doses of 100 mg/kg and 200 mg/kg effectively normalized HPA axis dysregulation and enhanced neuroplasticity. Increased concentrations of AFN demonstrated greater efficacy. Following AFN oral administration, adrenocorticotropic and corticosterone hormone levels exhibited significant or nearly significant reductions in comparison to subjects exposed to stress only. These changes align with the alleviation of stress and the normalization of the HPA axis. These findings elucidate AFN's role in stress mitigation, affirm its health benefits, validate its potential as a treatment for stress-related symptoms, confirm its physiological effectiveness, and emphasize its therapeutic promise.
Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that ...this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs), including benzene, toluene, and xylene (BTX), as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX.
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