Biological Microenvironment Research Articles

Identification of Novel Tumor Microenvironment-Related Long Noncoding RNAs to Determine the Prognosis and Response to Immunotherapy of Hepatocellular Carcinoma Patients.

Introduction: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors with poor prognosis. The tumor microenvironment (TME) plays a vital role in HCC progression. Thus, this research was designed to analyze the correlation between the TME and the prognosis of HCC patients and to construct a TME-related long noncoding RNA (lncRNA) signature to determine HCC patients’ prognosis and response to immunotherapy. Methods: We assessed the stromal–immune–estimate scores within the HCC microenvironment using the ESTIMATE (Estimation of Stromal and Immune Cells in Malignant Tumor Tissues Using Expression Data) algorithm based on The Cancer Genome Atlas database, and their associations with survival and clinicopathological parameters were also analyzed. Thereafter, differentially expressed lncRNAs were filtered out according to the immune and stromal scores. Cox regression analysis was performed to build a TME-related lncRNA risk signature. Kaplan–Meier analysis was used to explore the prognostic value of the risk signature. Furthermore, we explored the biological functions and immune microenvironment features in the high- and low-risk groups. Lastly, we probed the association of the risk model with treatment responses to immune checkpoint inhibitors (ICIs) in HCC. Results: The stromal, immune, and estimate scores were obtained utilizing the ESTIMATE algorithm for patients with HCC. Kaplan–Meier analysis showed that high scores were significantly correlated with better prognosis in HCC patients. Six TME-related lncRNAs were screened to construct the prognostic model. The Kaplan–Meier curves suggested that HCC patients with low risk had better prognosis than those with high risk. Receiver operating characteristic (ROC) curve and Cox regression analyses indicated that the risk model could predict HCC survival exactly and independently. Functional enrichment analysis revealed that some tumor- and immune-related pathways were activated in the high-risk group. We also revealed that some immune cells, which were important in enhancing immune responses toward cancer, were significantly increased in the low-risk group. In addition, there was a close correlation between ICIs and the risk signature, which can be used to predict the treatment responses of HCC patients. Conclusion: We analyzed the influence of the stromal, immune, and estimate scores on the prognosis of HCC patients. A novel TME-related lncRNA risk model was established, which could be effectively applied as an independent prognostic biomarker and predictor of ICIs for HCC patients.

A conductive supramolecular hydrogel creates ideal endogenous niches to promote spinal cord injury repair

The current effective method for treatment of spinal cord injury (SCI) is to reconstruct the biological microenvironment by filling the injured cavity area and increasing neuronal differentiation of neural stem cells (NSCs) to repair SCI. However, the method is characterized by several challenges including irregular wounds, and mechanical and electrical mismatch of the material-tissue interface. In the current study, a unique and facile agarose/gelatin/polypyrrole (Aga/Gel/PPy, AGP3) hydrogel with similar conductivity and modulus as the spinal cord was developed by altering the concentration of Aga and PPy. The gelation occurred through non-covalent interactions, and the physically crosslinked features made the AGP3 hydrogels injectable. In vitro cultures showed that AGP3 hydrogel exhibited excellent biocompatibility, and promoted differentiation of NSCs toward neurons whereas it inhibited over-proliferation of astrocytes. The in vivo implanted AGP3 hydrogel completely covered the tissue defects and reduced injured cavity areas. In vivo studies further showed that the AGP3 hydrogel provided a biocompatible microenvironment for promoting endogenous neurogenesis rather than glial fibrosis formation, resulting in significant functional recovery. RNA sequencing analysis further indicated that AGP3 hydrogel significantly modulated expression of neurogenesis-related genes through intracellular Ca2+ signaling cascades. Overall, this supramolecular strategy produces AGP3 hydrogel that can be used as favorable biomaterials for SCI repair by filling the cavity and imitating the physiological properties of the spinal cord.

Investigation of the role of the autophagic protein LC3B in the regulation of human airway epithelium cell differentiation in COPD using a biomimetic model.

Chronic obstructive pulmonary disease (COPD) is one of the most lethal chronic disease worldwide; however, the establishment of reliable in vitro models for exploring the biological mechanisms of COPD remains challenging. Here, we determined the differences in the expression and characteristics of the autophagic protein LC3B in normal and COPD human small airway epithelial cells and found that the nucleus of COPD cells obviously accumulated LC3B. We next established 3D human small airway tissues with distinct disease characteristics by regulating the biological microenvironment, extracellular matrix, and air-liquid interface culture methods. Using this biomimetic model, we found that LC3B affects the differentiation of COPD cells into basal, secretory, mucous, and ciliated cells. Moreover, although chloroquine and ivermectin effectively inhibited the expression of LC3B in the nucleus, chloroquine specifically maintained the performance of LC3B in cytoplasm, thereby contributing to the differentiation of ciliated cells and subsequent improvement in the beating functions of the cilia, whereas ivermectin only facilitated differentiation of goblet cells. We demonstrated that the autophagic mechanism of LC3B in the nucleus is one factor regulating the ciliary differentiation and function of COPD cells. Our innovative model can be used to further analyze the physiological mechanisms in the in vitro airway environment.

Alginate-based 3D cell culture technique to evaluate the half-maximal inhibitory concentration: an in vitro model of anticancer drug study for anaplastic thyroid carcinoma

BackgroundThree-dimensional (3D) cell culture methods are identified for simulating the biological microenvironment and demonstrating more similarity to in vivo circumstances. Anaplastic thyroid carcinoma (ATC) is a lethal endocrine malignancy. Despite different treatment approaches, no improvement in the survival rate of the patients has been shown. In this study, we used the 3D in vitro ATC model to investigate the cytotoxic effect of BI-847325 anticancer drug in two-dimensional (2D)- and 3D- cultured cells.MethodsHuman ATC cell lines, C643 and SW1736, were cultured in one percentage (w/v) sodium alginate. Spheroids were incubated in medium for one week. The reproducibility of the fabrication of alginate beads was evaluated. Encapsulation of the cells in alginate was examined by DAPI (4′,6-diamidino-2-phenylindole) staining. Survival of alginate-encapsulated cells was evaluated by CFSE (5,6-Carboxyfluorescein N-hydroxysuccinimidyl ester) staining. The population doubling times of C643 and SW1736 cell lines cultured in 2D monolayer as well as in 3D system were calculated. The cytotoxic effect of BI-847325 on 2D- and 3D- cultured cell lines was assessed for 24–72 h by MTT [3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide] assay. Finally, the 3D culture results were compared with the 2D culture method.ResultsThe half-maximal inhibitory concentration (IC50) values of BI-847325 were higher in 3D culture compared to 2D culture. The cytotoxicity data indicated that 3D in vitro models were more resistant to chemotherapy agents.ConclusionsThe findings of this study are beneficial for developing in vitro ATC 3D models to analyze the efficacy of different chemotherapy drugs and formulations.

A signal processor made from DNA assembly and upconversion nanoparticle for pharmacokinetic study

The real-time drug-release monitoring is important for pharmacokinetic study toward clinical applications. The accuracy is usually severely affected by the fluctuation of complex biological microenvironment and dosage variation. Herein, a novel signal processor, upconversion nanoparticle (UCNP)-DNA nanocomplex (UCDC) was constructed via rational DNA design, enabling NIR-excited real-time in vivo drug-release monitoring, and realizing real-time pharmacokinetic monitoring. The signal processor was constructed by interfacial assembly of circular DNA on UCNP and the subsequent epitaxial assembly of ultralong DNA. Ultralong DNA chain was programed with multiple desired functional regions: double-stranded region for chemotherapy drugs integrating, DNA aptamer for tumor cells targeting and hairpin/i-motif switchable structure for tumor microenvironment responsive drug release. Based on filter effect of loaded drug molecules, efficient switch of real-time drug-release to optical signal was realized. For signal output, the ratiometer of red upconversion emission (UCLR) and NIR upconversion emission (UCLNIR) was monitored (UCLR/UCLNIR), with UCLNIR as an internal reference. In a breast cancer mouse model, the signal processor system achieved accurate and reliable localized drug-release monitoring, which effectively minimized the influence of the internal microenvironment and dosage variation.

Three-dimensional spheroids of dedifferentiated fat cells enhance bone regeneration.

IntroductionMesenchymal stromal/stem cells (MSCs) are multipotent, self-renewing cells that are extensively used in tissue engineering. Dedifferentiated fat (DFAT) cells are derived from adipose tissues and are similar to MSCs. Three-dimensional (3D) spheroid cultures comprising MSCs mimic the biological microenvironment more accurately than two-dimensional cultures; however, it remains unclear whether DFAT cells in 3D spheroids possess high osteogenerative ability. Furthermore, it is unclear whether DFAT cells from 3D spheroids transplanted into calvarial bone defects are as effective as those from two-dimensional (2D) monolayers in promoting bone regeneration.MethodsWe compared the in vitro osteogenic potential of rat DFAT cells cultured under osteogenic conditions in 3D spheroids with that in 2D monolayers. Furthermore, to elucidate the ability of 3D spheroid DFAT cells to promote bone healing, we examined the in vivo osteogenic potential of transplanting DFAT cells from 3D spheroids or 2D monolayers into a rat calvarial defect model.ResultsOsteoblast differentiation stimulated by bone morphogenetic protein-2 (BMP-2) or osteogenesis-inducing medium upregulated osteogenesis-related molecules in 3D spheroid DFAT cells compared with 2D monolayer DFAT cells. BMP-2 activated phosphorylation in the canonical Smad 1/5 pathways in 3D spheroid DFAT cells but phosphorylated ERK1/2 and Smad2 in 2D monolayer DFAT cells. Regardless of osteogenic stimulation, the transplantation of 3D DFAT spheroid cells into rat calvarial defects promoted new bone formation at a greater extent than that of 2D DFAT cells.ConclusionsCompared with 2D DFAT cells, 3D DFAT spheroid cells promote osteoblast differentiation and new bone formation via canonical Smad 1/5 signaling pathways. These results indicate that transplantation of DFAT cells from 3D spheroids, but not 2D monolayers, accelerates bone healing.

The calcifying interface in a stony coral primary polyp: An interplay between seawater and an extracellular calcifying space

Stony coral exoskeletons build the foundation for the most biologically diverse marine ecosystems on Earth, coral reefs, which face major threats due to many anthropogenic–related stressors. Therefore, understanding coral biomineralization mechanisms is crucial for coral reef management in the coming decades and for using coral skeletons in geochemical studies. This study combines in–vivo imaging with cryo-electron microscopy and cryo–elemental mapping to gain novel insights into the biological microenvironment and the ion pathways that facilitate biomineralization in primary polyps of the stony coral Stylophora pistillata. We document increased tissue permeability in the primary polyp and a highly dispersed cell packing in the tissue directly responsible for producing the coral skeleton. This tissue arrangement may facilitate the intimate involvement of seawater at the mineralization site, also documented here. We further observe an extensive filopodial network containing carbon-rich vesicles extruding from some of the calicoblastic cells. Single-cell RNA-Sequencing data interrogation supports these morphological observations by showing higher expression of genes involved in filopodia and vesicle structure and function in the calicoblastic cells. These observations provide a new conceptual framework for resolving the ion pathway from the external seawater to the tissue-mineral interface in stony coral biomineralization processes.

Materials science and design principles of therapeutic materials in orthopedic and bone tissue engineering

The successful materials design for bone‐tissue engineering needs to understand the structure and composition of host bone tissue, and selecting appropriate biomimetic natural or tunable synthetic materials (biomaterials), such as polymers, bioceramics, metals, and composites. Materials that improve bone tissue engineering have tremendous potential for clinical applications to treat and regenerate various bone injuries and fractures. The drive to design bone grafts for bridging the gaps in orthopedic tissue regeneration results in a significant research thrust for designing and developing material for bone tissue regeneration. Recently, numerous challenges, including biomaterial designing, can well suit the biological, chemical and mechanical microenvironment of natural orthopedic tissues and adopt vascularization. Novel bio‐inspired materials attempt to enhance the biofunctionality that reconstruct microlevel biofactor and topographical signals from the extracellular environment are rapidly developing. The most important paradigm shift in orthopedic tissue engineering is the careful selection of scaffold, signals, and cell types to design biomaterials. Notwithstanding, the clinical outcome of orthopedic tissue regeneration was so vibrant years ago; however, so far, it failed to achieve the expected results and failed to translate in the clinical setting. In the current review, we discuss the aims and mechanism of bone tissue regeneration, biomaterial designing, and orthopedic tissue engineering requirements. Next, we highlight the principle for orthopedic tissue engineering and describe the strategies for enhancing material Bio‐functionality. Finally, we give the bench to bedside concept and concluding remarks with a special focus on future. The main purpose of current paper is to give a comprehensive overview, which is helpful for the researcher to distill this information and design future research strategies for designing materials for orthopedic and bone tissue engineering.

Mie resonant scattering-based refractive index sensor using a quantum dots-doped polylactic acid nanowire

An optical refractive index (RI) nanosensor with a high sensitivity and figure of merit (FOM), good stability, and biocompatibility is of great significance for biological detection and sensing in narrow spaces. However, the current optical RI nanosensors are mainly fabricated using metals, semiconductors, and quartz, which are not biocompatible and are even biotoxic, and often face a trade-off between a high sensitivity and a high FOM. Moreover, the sensors are mainly based on surface plasmon resonance, photonic crystals, fiber grating, etc., and, thus, most of them usually require a laser source with a specific optical wavelength or harsh excitation conditions, which are likely to cause photodamage and are unfavorable for biological applications. Hence, polylactic acid (PLA), a flexible dielectric material with good biocompatibility, is functioned by doping high refractive index quantum dots (QDs) and fabricated as a nanowire RI sensor. Doping the QDs into a PLA nanowire can improve the light confinement ability and then enhance Mie resonant scattering of the PLA nanowire, which is very beneficial to obtain a higher quality factor and then a higher-performance nanowire sensor. Under irradiation of a white light source, a high sensitivity with 833.78 nm/RIU (per refractive index unit) and the highest FOM of 9.64 RIU−1 are obtained. The good reliability and reproducibility of the sensors are further demonstrated. By choosing a proper diameter, the scattering peak of the nanosensor can be tuned into a biofriendly spectral range (600–900 nm), which predicts that the PLA nanowire RI sensors have a great potential in biological microenvironment monitoring, biosensing, and biomedical treatment.

Engineering strategies to capture the biological and biophysical tumor microenvironment in vitro.

Despite decades of research and advancements in diagnostic and treatment modalities, cancer remains a major global healthcare challenge. This is due in part to a lack of model systems that allow investigating the mechanisms underlying tumor development, progression, and therapy resistance under relevant conditions in vitro. Tumor cell interactions with their surroundings influence all stages of tumorigenesis and are shaped by both biological and biophysical cues including cell-cell and cell-extracellular matrix (ECM) interactions, tissue architecture and mechanics, and mass transport. Engineered tumor models provide promising platforms to elucidate the individual and combined contributions of these cues to tumor malignancy under controlled and physiologically relevant conditions. This review will summarize current knowledge of the biological and biophysical microenvironmental cues that influence tumor development and progression, present examples of in vitro model systems that are presently used to study these interactions and highlight advancements in tumor engineering approaches to further improve these technologies.

Stimuli‐responsive hydrogels: Fabrication and biomedical applications

AbstractDue to their similarity to some bio‐architectures, for example, extracellular matrix, hydrogels are considered as bio‐inspired networks with bio‐mimetic and bio‐functional properties. With natural cytocompatibility and biocompatibility, hydrogels nowadays are more and more involved in various bio‐applications including shape morphing, artificial muscles, soft robotics, regenerative medicine, and so on. As an important subclass, stimuli‐responsive hydrogels have been attracting interest within decades. In response to single or multi‐triggers in biological microenvironment, stimuli‐responsive hydrogels can undergo phase transition, stiffness change, or biochemical properties activation, which make them intriguing biomaterials with broad applications including sensing, drug delivery, tissue engineering, and wound healing. This review presents typical synthetic and natural gelators comprising small molecules and polymers as building blocks of functional architectures. The fabrication strategies of hydrogels varied from supramolecular assembly to dynamic covalent binding are detailed. Various exogenous or endogenous, physical or chemical, and synthetic or natural stimuli together with response mechanism, design principle are demonstrated. Through recent examples from different perspectives, such as bionic devices, wound dressing, and cargo carrier, the benefits and opportunities of stimuli‐responsive hydrogels for biological applications are highlighted. Finally, the current challenges and future prospects in view of translation from fundamental researches to clinical application are briefly discussed.

Noncanonical Amino Acids for Hypoxia-Responsive Peptide Self-Assembly and Fluorescence

Design of endogenous stimuli-responsive amino acids allows for precisely modulating proteins or peptides under a biological microenvironment and thereby regulating their performance. Herein we report a noncanonical amino acid 2-nitroimidazol-1-yl alanine and explore its functions in creation of the nitroreductase (NTR)-responsive peptide-based supramolecular probes for efficient hypoxia imaging. On the basis of the reduction potential of the nitroimidazole unit, the amino acid was synthesized via the Mitsunobu reaction between 2-nitroimidazole and a serine derivate. We elucidated the relationship between the NTR-responsiveness of the amino acid and the structural feature of peptides involving a series of peptides. This eventually facilitates development of aromatic peptides undergoing NTR-responsive self-assembly by rationally optimizing the sequences. Due to the intrinsic role of 2-nitroimidazole in the fluorescence quench, we created a morphology-transformable supramolecular probe for imaging hypoxic tumor cells based on NTR reduction. We found that the resulting supramolecular probes penetrated into solid tumors, thus allowing for efficient fluorescence imaging of tumor cells in hypoxic regions. Our findings demonstrate development of a readily synthesized and versatile amino acid with exemplified properties in creating fluorescent peptide nanostructures responsive to a biological microenvironment, thus providing a powerful toolkit for synthetic biology and development of novel biomaterials.

Collagen-based biomaterials for bone tissue engineering

In recent years, there has been increasing interest in using biomimetic materials for bone tissue engineering. However, the high immunogenicity and low mechanical properties of biomimetic materials limit their applications in vivo. As an essential component of the extracellular matrix in bone tissue, collagen is ideal because it easily degrades and has strong plasticity and low immunogenicity. However, pure collagen alone does not yield satisfactory experimental results. Therefore, biomimetic bone tissue engineering scaffolds are often prepared together with other bioactive materials to better replicate the bone tissue’s biological microenvironment. To better understand the engineered scaffolds, we have summarized and analyzed current research in collagen-based biomimetic bone tissue engineering. This review focuses on the acquisition and processing of collagen, the mechanisms involved in collagen-induced osteogenesis, the biomimetic materials composed of collagen and different materials, and the application of collagen-based bioactive materials in bone tissue engineering.

Distinguishing normal and inflammatory models by viscosity changes with sensitively mitochondrial-trackable fluorescent probe

Biological microenvironment plays a momentous role in the regulation of various vital activities, and its abnormal changes are often closely related to some diseases. Viscosity, as an indispensable part of microenvironment parameters, has always been one of the research hotspots of investigators. Herein, we constructed a new red-emitting fluorescent probe (HVM) to identify the abnormal situation of mitochondria through viscosity changes in the biological microenvironment. Interestingly, HVM has excellent optical properties such as large stokes shift (160 nm), viscosity sensitivity (195-fold), high photostability, and biochemical properties with low cytotoxicity and excellent biocompatibility. For these reasons, the novel probe could successfully be used to identify the normal and inflammatory models via viscosity changes in biological experiments. Therefore, we provided a convenient synthetic route to obtain viscosity sensor HVM with excellent application properties.

Porous nerve guidance conduits reinforced with braided composite structures of silk/magnesium filaments for peripheral nerve repair

Peripheral nerve repair is a common but challenging surgical treatment. Many artificial nerve grafts have been developed, including nerve guidance conduits (NGCs) with biocompatibility, suitable mechanical properties and topography to guide axon growth. However, there remains a need to promote nerve regeneration and accelerate functional recovery using NGCs for nerve reconstruction. Here, silk fibroin (SF) and magnesium (S/Mg) filaments were braided into an inner layer of NGC and freeze-dried with a solution of SF and chitosan (CS). The mechanical stress of these S/Mg-SF/CS conduits reached 2.8 ± 0.2 N and possessed high compression strength. The conduits were evaluated with subcutaneous implantation. Sustainable mechanical function was demonstrated when used to repair 10 mm sciatic nerve gaps in rats. The hollow NGCs improved neurochemotaxis from the damaged nerves. The wet weight ratio of the gastrocnemius muscle, a target muscle for the sciatic nerve related to motor and sensory functions in the NGC group, reached 83.5% of that in the autologous group in 8 weeks; the nerve ports at both ends of the NGC grew well. When the distal end of the regenerated nerve was observed by Transmission Electron Microscopy (TEM), there was no significance difference in the diameter and thickness of the myelin sheath of the distal nerve between the autograft and S/Mg-SF/CS group, indicating that S/Mg-SF/CS NGC in this study promoted the growth of damaged nerves and provided appropriate physio mechanical guidance, thus suggesting potential utility for this approach in artificial nerve transplantation. Statement of significance1. Porous nerve guidance conduits (NGCs) is reinforced by a braided composite structure consisting of silk/magnesium filaments, which provides the NGC with appropriate physio-mechanical guidance as well as sufficient stability to support the biological micro-environment during early-stages of nerve regeneration and functional recovery.2. Sufficient mechanical properties, biocompatibility with Schwan cells and good performance after sciatic nerve transplantation demonstrates that the S/Mg-SF/CS NGC in this study promotes the growth of damaged nerves and provides a suitable physio-mechanical guide for potential in artificial nerve transplantation.3. A facile scalable manufacturing process is achieved by utilizing multidisciplinary engineering, such as textile technologies, biomaterial engineering and medical science.

Multistage Adaptive Nanoparticle Overcomes Biological Barriers for Effective Chemotherapy.

Drug delivery systems (DDS) are extensively studied to improve the solubility, stability, pharmacokinetic, and biodistribution of chemotherapeutics. However, the drug delivery efficiency of traditional DDS is often limited by the complicated biological barriers in vivo. Herein, a multistage adaptive nanoparticle (MAN) that simultaneously overcomes multiple biological barriers to achieve tumor-targeted drug delivery with high efficiency is presented. MAN has a core-shell structure, in which both the core and the shell are made of responsive polymers. This structure allows MAN to present different surface properties to adapt to its surrounding biological microenvironment, thereby achieving enhanced stability in blood circulation, improved tumor accumulation and cellular internalization in tumor tissues, and effective release of drug in cells. With these unique characteristics, the MAN loaded with docetaxel achieves effective tumor suppression with reduced systemic toxicity. Furthermore, MAN can load almost any hydrophobic drugs, providing a general strategy for the tumor-targeted delivery of hydrophobic drugs to overcome the multiple biological barriers and improve the efficacy of chemotherapy.

Perfluorocarbon nanoemulsions create a beneficial O2 microenvironment in N2-fixing biological | inorganic hybrid

Powered by renewable electricity, biological | inorganic hybrids employ water-splitting electrocatalysis and generate H2 as reducing equivalents for microbial catalysis. The approach integrates the beauty of biocatalysis with the energy efficiency of inorganic materials for sustainable chemical production. Yet a successful integration requires delicate control of the hybrid's extracellular chemical environment. Such an argument is evident in the exemplary case of O2 because biocatalysis has a stringent requirement of O2 but the electrocatalysis may inadvertently perturb the oxidative pressure of biological moieties. Here we report the addition of perfluorocarbon (PFC) nanoemulsions promote a biocompatible O2 microenvironment in a O2-sensitive N2-fixing biological | inorganic hybrid. Langmuir-type nonspecific binding between bacteria and nanoemulsions facilitates O2 transport in bacterial microenvironment and leads to a 250% increase in efficiency for organic fertilizers within 120 hours. Controlling the biological microenvironment with nanomaterials heralds a general approach accommodating the compatibility in biological | inorganic hybrids.

Dual-emission NIR fluorescent probe sensitive response biological microenvironment and sulfur dioxide

The viscosity and sulfur dioxide (SO2) of mitochondria are key indicators for changes in the cell microenvironment. At present, the emission wavelength of fluorescent probes responding to viscosity was relatively short. Among of them, fewer probes responded to both viscosity and sulfur dioxide. Herein, we developed a NIR (Near Infrared) fluorescent probe Mito-Th (740 nm) for simultaneous detecting SO2 and viscosity in mitochondria: N,N-dimethyl-4(thiophen-2-yl)-aniline acts as fluorescent rotors to regulate the twisted intramolecular charge transfer (TICT) process for achieving viscosity response; the C = C of indole salt linked to thiophene responding to the nucleophilic addition of SO2. Thus, the probe responded to viscosity and SO2 by red and blue fluorescence channels, respectively. More importantly, we have successfully applied the probe Mito-Th to monitor both viscosity and SO2 of mitochondria in cells and zebrafish, and revealed the relationship between viscosity and SO2 during mitochondrial dysfunction. It will provide guidance for the regulation of mitochondrial dysfunction.

Self-Standing Photo-Crosslinked Hydrogel Construct: in vitro Microphysiological Vascular Model

Modeling of the human vascular microphysiological system (MPS) has gained attention due to precise prediction of drug response and toxicity during drug screening process. Developing a physiologically equivalent vascular MPS still remains complex as it demands the recapitulation of dynamic structural and biological microenvironment similar to native vasculature. Hence, an ideal MPS would involve developing perfusable 3D in vitro models with multilayered human vascular cells encapsulated in a matrix to regulate the vascular tone resembling the native. Several attempts to model such anatomically accurate physiological and pathological blood vessels often fail to harmonize the essential vascular microenvironment. For instance, conventional microfluidic-based approaches employed for vascular MPS, though offering creation of perfusable channel, do not replicate the vascular hierarchical cellular arrangement due to planar geometry and confluent monolayered cell seeding. Also, recent advances with 3D biofabrication strategies are still limited by fabrication of small-diameter constructs and scalability besides post-processing techniques that indirectly distort the structural integrity of the hydrogel tubular constructs. These existing limitations toward fabricating a relevant vascular MPS demand a facile and mechanically stable construct. Hence, the present study is aimed toward developing a stable viable self-standing perfusable hydrogel construct by a rapid and scalable strategy toward vascular MPS application. The fabricated tubular constructs were found to be structurally stable with end-to-end perfusability exhibiting their potential as self-standing perfusable structures. Also, the construct exhibited nonhemolytic behavior with perfusion of red blood cells inside the luminal channel. The present study evidences creation of a dual-crosslinked stable, viable self-standing hydrogel construct with multilayered homogenous distribution of viable smooth muscle cells throughout the construct, thereby demonstrating its applicability as a promising 3D in vitro vascular microphysiological system.

Multiple-Molecule Drug Design Based on Systems Biology Approaches and Deep Neural Network to Mitigate Human Skin Aging.

Human skin aging is affected by various biological signaling pathways, microenvironment factors and epigenetic regulations. With the increasing demand for cosmetics and pharmaceuticals to prevent or reverse skin aging year by year, designing multiple-molecule drugs for mitigating skin aging is indispensable. In this study, we developed strategies for systems medicine design based on systems biology methods and deep neural networks. We constructed the candidate genomewide genetic and epigenetic network (GWGEN) via big database mining. After doing systems modeling and applying system identification, system order detection and principle network projection methods with real time-profile microarray data, we could obtain core signaling pathways and identify essential biomarkers based on the skin aging molecular progression mechanisms. Afterwards, we trained a deep neural network of drug–target interaction in advance and applied it to predict the potential candidate drugs based on our identified biomarkers. To narrow down the candidate drugs, we designed two filters considering drug regulation ability and drug sensitivity. With the proposed systems medicine design procedure, we not only shed the light on the skin aging molecular progression mechanisms but also suggested two multiple-molecule drugs for mitigating human skin aging from young adulthood to middle age and middle age to old age, respectively.