Strong near-infrared upconversion luminescence of the Er3+/Y3+ co-doped YbVO4 phosphor for multimode optical temperature measurement.

This study explored the enhancement of near-infrared emissions in YbVO4: Er3+ through Y3+ ion doping under a 980 nm laser excitation. The phosphor exhibits weak green emissions at 527 nm (2H11/2 â†’ 4I15/2) and 553 nm (4S3/2 â†’ 4I15/2), red emissions at 654 nm (4F9/2 â†’ 4I15/2), and a strong near-infrared emission at 803 nm (4I9/2 â†’ 4I15/2). Optimal doping concentration of Y3+ ion in YbVO4: 0.02 Er3+ was determined to be 0.1, resulting in a 7.6-fold enhancement of near-infrared luminescence. This enhancement is attributed to defect bands facilitating energy transfer from green and red levels to the near-infrared levels. Furthermore, a multi-mode temperature sensor based on YbVO4: Er3+/Y3+ was developed, offering four distinct temperature sensing modes: TCEL of 2H11/2/4S3/2, NTCEL of 2H11/2/4F9/2 and 4S3/2/4F9/2, and single luminescence emission intensity of 4I9/2 energy level. The sensor demonstrates maximum relative sensitivities of 1.17 % K-1 at 298 K, 0.66 % K-1 at 298 K, 0.41 % K-1 at 298 K and 1.29 % K-1 at 673 K. YbVO4: Er3+/Y3+ phosphor exhibits high temperature sensitivity, showcasing significant potential for optical temperature sensing applications.

Combination of Cinnamaldehyde/ß-cyclodextrin inclusion complex and L-phenylalanine effectively reduces the postharvest green mold in citrus fruit.

The essential oil and ß-cyclodextrin inclusion complex was able to inhibit the growth of Penicillium digitatum, a damaging pathogen that causes green mold in citrus fruit. In this study, cinnamaldehyde-ß-cyclodextrin inclusion complex (ß-CDCA) for controlling citrus green mold was synthesized by the co-precipitation method. Characterization of ß-CDCA revealed that the aromatic ring skeleton of cinnamaldehyde (CA) was successfully embedded into the cavity of ß-CD to form the inclusion complex. ß-CDCA inhibited P. digitatum at a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 4.0 g/L. FT-IR spectroscopy analysis, calcofluor white staining, extracellular alkaline phosphatase (AKP) activity and propidium iodide (PI) staining of hyphae morphology showed that ß-CDCA may damage the cell ultrastructure and membrane permeability of P. digitatum. The study further demonstrated that hydrogen peroxide (H2O2), malondialdehyde (MDA), and reactive oxygen species (ROS) markedly accumulated in 1/2 MIC ß-CDCA treated hyphae. This implied that ß-CDCA inhibited growth of P. digitatum by the triggering oxidative stress, which may have caused cell death by altering cell membrane permeability. In addition, in vivo results showed that ß-CDCA alone or combined with L-phenylalanine (L-PHe) displayed a comparable level to that of prochloraz. Therefore, ß-CDCA combined with L-PHe can thus be used as an eco-friendly preservative for the control green mold in postharvest citrus fruit.

Single-cell omics: experimental workflow, data analyses and applications.

Cells are the fundamental units of biological systems and exhibit unique development trajectories and molecular features. Our exploration of how the genomes orchestrate the formation and maintenance of each cell, and control the cellular phenotypes of various organismsis, is both captivating and intricate. Since the inception of the first single-cell RNA technology, technologies related to single-cell sequencing have experienced rapid advancements in recent years. These technologies have expanded horizontally to include single-cell genome, epigenome, proteome, and metabolome, while vertically, they have progressed to integrate multiple omics data and incorporate additional information such as spatial scRNA-seq and CRISPR screening. Single-cell omics represent a groundbreaking advancement in the biomedical field, offering profound insights into the understanding of complex diseases, including cancers. Here, we comprehensively summarize recent advances in single-cell omics technologies, with a specific focus on the methodology section. This overview aims to guide researchers in selecting appropriate methods for single-cell sequencing and related data analysis.

Large enhancement of red upconversion luminescence in beta Ba2Sc0.67Yb0.3Er0.03AlO5 phosphor via Mn2+ ions doping for thermometry.

Here, this study reports single-band red upconversion emission in ß-Ba2ScAlO5: Yb3+/Er3+ phosphor by doping Mn2+. The optimum concentration of Mn2+ ions in ß-Ba2ScAlO5: Yb3+/Er3+ phosphor was 0.20. The intensity of red and green emissions is increased by 27.4 and 19.3 times, respectively. Compared with the samples without Mn2+ ions, the red-green integral strength ratio of ß-Ba2ScAlO5: Yb3+/Er3+/Mn2+ sample was significantly increased by 28.4 times, reaching 110.9. The UCL mechanism was explored by analyzing the down-conversion luminescence spectra, absorption spectra, UCL spectra, and upconversion fluorescence lifetime decay curves of Yb3+/Er3+/Mn2+ co-doped ß-Ba2ScAlO5. The enhancement of upconversion red light is achieved through energy transfer between defect bands and Er3+ ions, as well as energy transfer between Mn2+ ions and Er3+ ions. In addition, the Mn2+ doped ß-Ba2ScAlO5: Yb3+/Er3+ red UCL phosphors have great potential for ambient temperature sensing in the 298-523 K temperature range. The maximum sensitivity of ß-Ba2ScAlO5: Yb3+/Er3+/Mn2+ phosphor as a temperature sensor at 523 K is 0.0247 K-1.

Octanal enhances disease resistance in postharvest citrus fruit by the biosynthesis and metabolism of aromatic amino acids.

Octanal was found to be able to reduce green mold incidence in citrus fruit by a defense response mechanism. However, the underlying mechanism remains largely unclear. Herein, the metabolomics, RNA-seq and biochemical analyses were integrated to explore the effect of octanal on disease resistance in harvested citrus fruit. Results showed that octanal fumigation at 40 µL L-1 was effective in controlling citrus green mold. Metabolomics analysis showed that octanal mainly led to the accumulation of some plant hormones including methyl jasmonate, abscisic acid, indole-3-butyric acid, indoleacetic acid (IAA), salicylic acid, and gibberellic acid and many phenylpropanoid metabolites including cinnamyl alcohol, hesperidin, dihydrokaempferol, vanillin, quercetin-3-O-malonylglucoside, curcumin, naringin, chrysin, coniferin, calycosin-7-O-ß-D-glucoside, trans-cinnamaldehyde, and 4',5,7-trihydroxy-3,6-dimethoxyflavone. Particularly, IAA and hesperidin were dramatically accumulated in the peel, which might be the contributors to the resistance response. Additionally, transcriptome analysis showed that octanal greatly activated the biosynthesis and metabolism of aromatic amino acids. This was further verified by the accumulation of some metabolites (shikimic acid, tryptophan, tyrosine, phenylalanine, IAA, total phenolics, flavonoids and lignin), increase in some enzyme activities (phenylalanine ammonia-lyase, tyrosine ammonia-lyase, 4-coumarate CoA ligase, cinnamic acid 4-hydroxylase, polyphenol oxidase, and peroxidase), up-regulation of some genes (tryptophan pyruvate aminotransferase, aldehyde dehydrogenase, shikimate kinase and shikimate dehydrogenase) expressions and molecular docking results. Thus, these results indicate that octanal is an efficient strategy for the control of postharvest green mold by triggering the defense response in citrus fruit.

Multi-slice spatial transcriptome domain analysis with SpaDo.

With the rapid advancements in spatial transcriptome sequencing, multiple tissue slices are now available, enabling the integration and interpretation of spatial cellular landscapes. Herein, we introduce SpaDo, a tool for multi-slice spatial domain analysis, including modules for multi-slice spatial domain detection, reference-based annotation, and multiple slice clustering at both single-cell and spot resolutions. We demonstrate SpaDo's effectiveness with over 40 multi-slice spatial transcriptome datasets from 7 sequencing platforms. Our findings highlight SpaDo's potential to reveal novel biological insights in multi-slice spatial transcriptomes.

Characterization of Antimicrobial Poly(Lactic Acid)- and Polyurethane-Based Materials Enduring Closed-Loop Recycling with Applications in Space.

Recent studies have shown that astronauts experience altered immune response behavior during spaceflight, resulting in heightened susceptibility to illness. Resources and resupply shuttles will become scarcer with longer duration spaceflight, limiting access to potentially necessary medical treatment and facilities. Thus, there is a need for preventative health countermeasures that can exploit in situ resource utilization technologies during spaceflight, such as additive manufacturing (i.e., 3D printing). The purpose of the current study was to test and validate recyclable antimicrobial materials compatible with additive manufacturing. Antimicrobial poly(lactic acid)- and polyurethane-based materials compatible with 3D printing were assessed for antimicrobial, mechanical, and chemical characteristics before and after one closed-loop recycling cycle. Our results show high biocidal efficacy (>90%) of both poly(lactic acid) and polyurethane materials while retaining efficacy post recycling, except for recycled-state polyurethane which dropped from 98.91% to 0% efficacy post 1-year accelerated aging. Significant differences in tensile and compression characteristics were observed post recycling, although no significant changes to functional chemical groups were found. Proof-of-concept medical devices developed show the potential for the on-demand manufacturing and recyclability of typically single-use medical devices using antimicrobial materials that could serve as preventative health countermeasures for immunocompromised populations, such as astronauts during spaceflight.

Long-term mortality in patients with end-stage renal disease undergoing hemodialysis and peritoneal dialysis: a propensity score matching retrospective study.

BACKGROUND: Hemodialysis (HD) and peritoneal dialysis (PD) are effective ways to treat end-stage renal disease (ERSD). This study aimed to investigate the differences in survival and the factors that influence it in patients with end-stage renal disease treated with HD or PD. METHODS: We retrospectively analyzed factors related to all-cause death with renal replacement therapy and compared the long-term mortality between HD and PD strategies in patients with ESRD who started HD or PD treatment in our renal HD center between January 1, 2008, and December 1, 2021. RESULTS: Overall, 1,319 patients were included, comprising 690 and 629 patients in the HD and PD groups, respectively, according to the inclusion criteria. After propensity matching, 922 patients remained, with 461 (50%) patients each in the two groups. There were no significant differences in the 1-, 2-, 3-, and 4-year mortality rates between the HD and PD groups (all p > .05). However, the 5- and 10-year mortality rates of the matched patients were 15.8%. 17.6% in the HD group and 21.0%. 27.3% in the PD group, respectively. The 5- and 10-year mortality rates were significantly lower in the HD group (all p < .05) as compared to the PD group. After matching, Kaplan-Meier curve analysis with log-rank test was performed, which showed a significant difference in the survival rates between the two groups (p = .001). Logistic multifactor regression analysis revealed that age, weight, hypertension, serum creatinine, and combined neoplasms influenced the survival rate of patients with ESRD (p < .05). In contrast, age, hypertension, parathyroid hormone (PTH), serum creatinine, and peripheral vascular diseases (PVD) influenced the survival rate of patients in the HD group (p < .05), and age and weight influenced the survival rate of patients in the PD group (p < .05). CONCLUSIONS: This study found that long-term mortality rates were higher in the PD group than that in the HD group, indicating that HD may be superior to PD.

Differentiated mesenchymal stem cells-derived exosomes immobilized in decellularized sciatic nerve hydrogels for peripheral nerve repair.

Peripheral nerve injury (PNI) and the limitations of current treatments often result in incomplete sensory and motor function recovery, which significantly impact the patient's quality of life. While exosomes (Exo) derived from stem cells and Schwann cells have shown promise on promoting PNI repair following systemic administration or intraneural injection, achieving effective local and sustained Exo delivery holds promise to treat local PNI and remains challenging. In this study, we developed Exo-loaded decellularized porcine nerve hydrogels (DNH) for PNI repair. We successfully isolated Exo from differentiated human adipose-derived mesenchymal stem cells (hADMSC) with a Schwann cell-like phenotype (denoted as dExo). These dExo were further combined with polyethylenimine (PEI), and DNH to create polyplex hydrogels (dExo-loaded pDNH). At a PEI content of 0.1%, pDNH showed cytocompatibility for hADMSCs and supported neurite outgrowth of dorsal root ganglions. The sustained release of dExos from dExo-loaded pDNH persisted for at least 21 days both in vitro and in vivo. When applied around injured nerves in a mouse sciatic nerve crush injury model, the dExo-loaded pDNH group significantly improved sensory and motor function recovery and enhanced remyelination compared to dExo and pDNH only groups, highlighting the synergistic regenerative effects. Interestingly, we observed a negative correlation between the number of colony-stimulating factor-1 receptor (CSF-1R) positive cells and the extent of PNI regeneration at the 21-day post-surgery stage. Subsequent in vitro experiments demonstrated the potential involvement of the CSF-1/CSF-1R axis in Schwann cells and macrophage interaction, with dExo effectively downregulating CSF-1/CSF-1R signaling.

Digital Light Processing 4D Printing of Poloxamer Micelles for Facile Fabrication of Multifunctional Biocompatible Hydrogels as Tailored Wearable Sensors.

The lack of both digital light processing (DLP) compatible and biocompatible photopolymers, along with inappropriate material properties required for wearable sensor applications, substantially hinders the employment of DLP 3D printing in the fabrication of multifunctional hydrogels. Herein, we discovered and implemented a photoreactive poloxamer derivative, Pluronic F-127 diacrylate, which overcomes these limitations and is optimized to achieve DLP 3D printed micelle-based hydrogels with high structural complexity, resolution, and precision. In addition, the dehydrated hydrogels exhibit a shape-memory effect and are conformally attached to the geometry of the detection point after rehydration, which implies the 4D printing characteristic of the fabrication process and is beneficial for the storage and application of the device. The excellent cytocompatibility and in vivo biocompatibility further strengthen the potential application of the poloxamer micelle-based hydrogels as a platform for multifunctional wearable systems. After processing them with a lithium chloride (LiCl) solution, multifunctional conductive ionic hydrogels with antifreezing and antiswelling properties along with good transparency and water retention are easily prepared. As capacitive flexible sensors, the DLP 3D printed micelle-based hydrogel devices exhibit excellent sensitivity, cycling stability, and durability in detecting multimodal deformations. Moreover, the DLP 3D printed conductive hydrogels are successfully applied as real-time human motion and tactile sensors with satisfactory sensing performances even in a -20 °C low-temperature environment.

Multiscale embedded printing of engineered human tissue and organ equivalents.

Creating tissue and organ equivalents with intricate architectures and multiscale functional feature sizes is the first step toward the reconstruction of transplantable human tissues and organs. Existing embedded ink writing approaches are limited by achievable feature sizes ranging from hundreds of microns to tens of millimeters, which hinders their ability to accurately duplicate structures found in various human tissues and organs. In this study, a multiscale embedded printing (MSEP) strategy is developed, in which a stimuli-responsive yield-stress fluid is applied to facilitate the printing process. A dynamic layer height control method is developed to print the cornea with a smooth surface on the order of microns, which can effectively overcome the layered morphology in conventional extrusion-based three-dimensional bioprinting methods. Since the support bath is sensitive to temperature change, it can be easily removed after printing by tuning the ambient temperature, which facilitates the fabrication of human eyeballs with optic nerves and aortic heart valves with overhanging leaflets on the order of a few millimeters. The thermosensitivity of the support bath also enables the reconstruction of the full-scale human heart on the order of tens of centimeters by on-demand adding support bath materials during printing. The proposed MSEP demonstrates broader printable functional feature sizes ranging from microns to centimeters, providing a viable and reliable technical solution for tissue and organ printing in the future.

Evaluation of Tyrosine Kinase Inhibitors Loaded Injectable Hydrogels for Improving Connexin43 Gap Junction Intercellular Communication.

Myocardial infarction (MI) is one of the leading causes of death in the developed world, and the loss of cardiomyocytes plays a critical role in the pathogenesis of heart failure. Implicated in this process is a decrease in gap junction intercellular communication due to remodeling of Connexin43 (Cx43). We previously identified that intraperitoneal injection of the Pyk2 inhibitor PF4618433 reduced infarct size, maintained Cx43 at the intercalated disc in left ventricle hypertrophic myocytes, and improved cardiac function in an MI animal model of heart failure. With the emergence of injectable hydrogels as a therapeutic toward the regeneration of cardiac tissue after MI, here, we provide proof of concept that the release of tyrosine kinase inhibitors from hydrogels could have beneficial effects on cardiomyocytes. We developed an injectable hydrogel consisting of thiolated hyaluronic acid and P123-maleimide micelles that can incorporate PF4618433 as well as the Src inhibitor Saracatinib and achieved sustained release (of note, Src activates Pyk2). Using neonatal rat ventricular myocytes in the presence of a phorbol ester, endothelin-1, or phenylephrine to stimulate cardiac hypertrophy, the release of PF4618433 from the hydrogel had the same ability to decrease Cx43 tyrosine phosphorylation and maintain Cx43 localization at the plasma membrane as when directly added to the growth media. Additional beneficial effects included decreases in apoptosis, the hypertrophic marker atrial natriuretic peptide (ANP), and serine kinases upregulated in hypertrophy. Finally, the presence of both PF4618433 and Saracatinib further decreased the level of ANP and apoptosis than each inhibitor alone, suggesting that a combinatorial approach may be most beneficial. These findings provide the groundwork to test if tyrosine kinase inhibitor release from hydrogels will have a beneficial effect in an animal model of MI-induced heart failure.

Engineering Neurotoxin-Functionalized Exosomes for Targeted Delivery to the Peripheral Nervous System.

The administration of therapeutics to peripheral nerve tissue is challenging due to the complexities of peripheral neuroanatomy and the limitations imposed by the blood-nerve barrier (BNB). Therefore, there is a pressing need to enhance delivery effectiveness and implement targeted delivery methods. Recently, erythrocyte-derived exosomes (Exos) have gained widespread attention as biocompatible vehicles for therapeutics in clinical applications. However, engineering targeted Exos for the peripheral nervous system (PNS) is still challenging. This study aims to develop a targeted Exo delivery system specifically designed for presynaptic terminals of peripheral nerve tissue. The clostridium neurotoxin, tetanus toxin-C fragment (TTC), was tethered to the surface of red blood cell (RBC)-derived Exos via a facile and efficient bio-orthogonal click chemistry method without a catalyst. Additionally, Cyanine5 (Cy5), a reactive fluorescent tag, was also conjugated to track Exo movement in both in vitro and in vivo models. Subsequently, Neuro-2a, a mouse neuronal cell line, was treated with dye-labeled Exos with/without TTC in vitro, and the results indicated that TTC-Exos exhibited more efficient accumulation along the soma and axonal circumference, compared to their unmodified counterparts. Further investigation, using a mouse model, revealed that within 72 h of intramuscular administration, engineered TTC-Exos were successfully transported into the neuromuscular junction and sciatic nerve tissues. These results indicated that TTC played a crucial role in the Exo delivery system, improving the affinity to peripheral nerves. These promising results underscore the potential of using targeted Exo carriers to deliver therapeutics for treating peripheral neuropathies.

Structure-decoupled functional connectome-based brain age prediction provides higher association to cognition.

Brain age prediction as well as the prediction difference has been well examined to be a potential biomarker for brain disease or abnormal aging process. However, less knowledge was reported for the cognitive association within normal population. In this study, we proposed a novel approach to brain age prediction by structure-decoupled functional connectome. The original functional connectome was decomposed and decoupled into a structure-decoupled functional connectome using structural connectome harmonics. Our method was applied to a large dataset of normal aging individuals and achieved a high correlation between predicted and chronological age (r = 0.77). Both the original FC and structure-decoupled FC could be well-trained in a brain age prediction model. Significant remarkable relationships between the brain age prediction difference (predicted age minus chronological age) and cognitive scores were discovered. However, the brain age-predicted difference driven by structure-decoupled FC showed a stronger correction to the two cognitive scores (MMSE: r = -0.27, P -value = 0.002; MoCA: r = -0.32, P -value = 0.0003). Our findings suggest that our structure-decoupled functional connectivity approach could provide a more individual-specific functional network, leading to improved brain age prediction performance and a better understanding of cognitive decline in aging.

Personalized tumor combination therapy optimization using the single-cell transcriptome.

BACKGROUND: The precise characterization of individual tumors and immune microenvironments using transcriptome sequencing has provided a great opportunity for successful personalized cancer treatment. However, the cancer treatment response is often characterized by in vitro assays or bulk transcriptomes that neglect the heterogeneity of malignant tumors in vivo and the immune microenvironment, motivating the need to use single-cell transcriptomes for personalized cancer treatment. METHODS: Here, we present comboSC, a computational proof-of-concept study to explore the feasibility of personalized cancer combination therapy optimization using single-cell transcriptomes. ComboSC provides a workable solution to stratify individual patient samples based on quantitative evaluation of their personalized immune microenvironment with single-cell RNA sequencing and maximize the translational potential of in vitro cellular response to unify the identification of synergistic drug/small molecule combinations or small molecules that can be paired with immune checkpoint inhibitors to boost immunotherapy from a large collection of small molecules and drugs, and finally prioritize them for personalized clinical use based on bipartition graph optimization. RESULTS: We apply comboSC to publicly available 119 single-cell transcriptome data from a comprehensive set of 119 tumor samples from 15 cancer types and validate the predicted drug combination with literature evidence, mining clinical trial data, perturbation of patient-derived cell line data, and finally in-vivo samples. CONCLUSIONS: Overall, comboSC provides a feasible and one-stop computational prototype and a proof-of-concept study to predict potential drug combinations for further experimental validation and clinical usage using the single-cell transcriptome, which will facilitate and accelerate personalized tumor treatment by reducing screening time from a large drug combination space and saving valuable treatment time for individual patients. A user-friendly web server of comboSC for both clinical and research users is available at www.combosc.top . The source code is also available on GitHub at https://github.com/bm2-lab/comboSC .

A Facile Strategy for the Fabrication of Cell-laden Porous Alginate Hydrogels Based on Two-phase Aqueous Emulsions.

Porous alginate hydrogels possess many advantages as cell carriers. However, current pore generation methods require either complex or harsh fabrication processes, toxic components, or extra purification steps, limiting the feasibility and affecting the cellular survival and function. In this study, a simple and cell-friendly approach to generate highly porous cell-laden alginate hydrogels based on two-phase aqueous emulsions is reported. The pre-gel solutions, which contain two immiscible aqueous phases of alginate and caseinate, are crosslinked by calcium ions. The porous structure of the hydrogel construct is formed by subsequently removing the caseinate phase from the ion-crosslinked alginate hydrogel. Those porous alginate hydrogels possess heterogeneous pores around 100 µm and interconnected paths. Human white adipose progenitors (WAPs) encapsulated in these hydrogels self-organize into spheroids and show enhanced viability, proliferation, and adipogenic differentiation, compared to non-porous constructs. As a proof of concept, this porous alginate hydrogel platform is employed to prepare core-shell spheres for coculture of WAPs and colon cancer cells, with WAP clusters distributed around cancer cell aggregates, to investigate cellular crosstalk. This efficacious approach is believed to provide a robust and versatile platform for engineering porous-structured alginate hydrogels for applications as cell carriers and in disease modeling.

γ-Cyclodextrin encapsulated thymol for citrus preservation and its possible mechanism against Penicillium digitatum.

The volatility of essential oils greatly limits their industrial applications. Here, we successfully prepared γ-cyclodextrin (γ-CD) inclusion compounds (γ-CDTL) containing thymol (TL) for the control of green mold caused by Penicillium digitatum (P. digitatum) in citrus fruit. In vitro experiment showed that the minimum fungicidal concentration (MFC) of γ-CDTL against the hyphae growth of P. digitatum was 2.0 g/L, and 8 × MFC treatment significantly reduced the occurrence of green mold in citrus fruit and had no adverse effect on fruit quality in vivo test compared to prochloraz. Scanning electron microscopy (SEM), x-ray diffraction (XRD), fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), physical properties and sustained release properties were also performed, results indicated that the hydrogen bonds between TL and γ-CD were the basis for the formation of γ-CDTL. We further investigated the inhibition mechanism of γ-CDTL. SEM and TEM experiments showed that γ-CDTL treatment caused severe damage to the hyphal morphology and cells in 30 min and disrupted the permeability of P. digitatum mycelial cell walls by increasing the chitinase activity, thus accelerating the leakage of intracellular lysates. However, the integrity of the cell membrane was obviously damaged only after 60 min of treatment. In conclusion, we prepared a novel inclusion complex γ-CDTL with obvious antifungal effects and preliminarily elucidated its inclusion mechanism and antifungal mechanism. γ-CDTL might be a potent alternative to chemical fungicides for controlling the postharvest decay of citrus.

Embedded Bioprinting of Breast Tumor Cells and Organoids Using Low-Concentration Collagen-Based Bioinks.

Bioinks for 3D bioprinting of tumor models should not only meet printability requirements but also accurately maintain and support phenotypes of tumor surrounding cells to recapitulate key tumor hallmarks. Collagen is a major extracellular matrix protein for solid tumors, but low viscosity of collagen solution has made 3D bioprinted cancer models challenging. This work produces embedded, bioprinted breast cancer cells and tumor organoid models using low-concentration collagen I based bioinks. The biocompatible and physically crosslinked silk fibroin hydrogel is used to generate the support bath for the embedded 3D printing. The composition of the collagen I based bioink is optimized with a thermoresponsive hyaluronic acid-based polymer to maintain the phenotypes of both the noninvasive epithelial and invasive breast cancer cells, as well as cancer-associated fibroblasts. Mouse breast tumor organoids are bioprinted using optimized collagen bioink to mimic in vivo tumor morphology. A vascularized tumor model is also created using a similar strategy, with significantly enhanced vasculature formation under hypoxia. This study shows the great potential of embedded bioprinted breast tumor models utilizing a low-concentration collagen-based bioink for advancing the understanding of tumor cell biology and facilitating drug discovery research.

Advances, challenges, and prospects for surgical suture materials.

As one of the long-established and necessary medical devices, surgical sutures play an essentially important role in the closing and healing of damaged tissues and organs postoperatively. The recent advances in multiple disciplines, like materials science, engineering technology, and biomedicine, have facilitated the generation of various innovative surgical sutures with humanization and multi-functionalization. For instance, the application of numerous absorbable materials is assuredly a marvelous progression in terms of surgical sutures. Moreover, some fantastic results from recent laboratory research cannot be ignored either, ranging from the fiber generation to the suture structure, as well as the suture modification, functionalization, and even intellectualization. In this review, the suture materials, including natural or synthetic polymers, absorbable or non-absorbable polymers, and metal materials, were first introduced, and then their advantages and disadvantages were summarized. Then we introduced and discussed various fiber fabrication strategies for the production of surgical sutures. Noticeably, advanced nanofiber generation strategies were highlighted. This review further summarized a wide and diverse variety of suture structures and further discussed their different features. After that, we covered the advanced design and development of surgical sutures with multiple functionalizations, which mainly included surface coating technologies and direct drug-loading technologies. Meanwhile, the review highlighted some smart and intelligent sutures that can monitor the wound status in a real-time manner and provide on-demand therapies accordingly. Furthermore, some representative commercial sutures were also introduced and summarized. At the end of this review, we discussed the challenges and future prospects in the field of surgical sutures in depth. This review aims to provide a meaningful reference and guidance for the future design and fabrication of innovative surgical sutures. STATEMENT OF SIGNIFICANCE: This review article introduces the recent advances of surgical sutures, including material selection, fiber morphology, suture structure and construction, as well as suture modification, functionalization, and even intellectualization. Importantly, some innovative strategies for the construction of multifunctional sutures with predetermined biological properties are highlighted. Moreover, some important commercial suture products are systematically summarized and compared. This review also discusses the challenges and future prospects of advanced sutures in a deep manner. In all, this review is expected to arouse great interest from a broad group of readers in the fields of multifunctional biomaterials and regenerative medicine.