A specific aggregation-induced emission-conjugated polymer enables visual monitoring of osteogenic differentiation

Fluorescent monitoring osteogenic differentiation of osteosarcoma cells with an aggregation-induced emission probe

Osteosarcoma is widely believed to be an osteogenic differentiation disorder. In recent years, to further understand this disease, a lot resources were poured into the potential link between differentiation defects and tumorigenesis. Long-term monitoring of the differentiation progress of osteosarcoma cells is of great importance. In order to better promote the research, we have developed a novel fluorescent probe called PTB-EDTA, which exhibits remarkable bio-compatibility and demonstrates high selectivity towards osteosarcoma cells. Not only is the PTB-EDTA is capable of live cell imaging while conventional histology requires to kill the cells, its fluorescence is also enhanced as the osteogenic differentiation proceeding. These properties make PTB-EDTA a promising tool for monitoring osteosarcoma cells.

The effects of matrix stiffness on immune cells in bone biology

Bone and immune cells typically inhabit the same microenvironment and engage in mutual interactions to collectively execute the functions of the "osteoimmune system." Establishing a harmonized and enduring osteoimmune system significantly enhances bone regeneration, necessitating the maintenance of bone and immune homeostasis. Recently, mechanobiology has garnered increasing interest in bone tissue engineering, with matrix stiffness emerging as a crucial parameter that has been extensively investigated. The effect of matrix stiffness on bone homeostasis remains relatively clear. Soft substrates tend to significantly affect the chondrogenic differentiation of bone marrow mesenchymal stem cells, whereas increasing matrix stiffness is advantageous for osteogenic differentiation. Increased stiffness increases osteoclast differentiation and activity. Additionally, there is increasing emphasis on immune homeostasis, which necessitates dynamic communication between immune cells. Immune cells are crucial in initiating bone regeneration and driving early inflammatory responses. Functional changes induced by matrix stiffness are pivotal for determining the outcomes of engineered tissue mimics. However, inconsistent and incomparable findings regarding the responses of different immune cells to matrix stiffness can be perplexing owing to variations in the stiffness range, measurement methods, and other factors. Therefore, this study aimed to provide a comprehensive review of the specific effects of matrix stiffness on diverse immune cells, with a particular focus on its implications for bone regeneration, which would offer theoretical insights into the treatment of large segmental bony defects and assist in the clinical development of new engineering strategies.

A porous form Coomassie brilliant blue G250-isorhamnetin fluorescent composite coated with acrylic resin for tumor cell imaging

Four distinct fluorescence complexes, the fluorescent complex-1 (FC-1), fluorescent complex-2 (FC-2), fluorescent complex third (FC-3) and fluorescent complex fourth (FC-4), were created using isorhamnetin and Coomassie brilliant blue G250 as raw materials. The issue of isorhamnetin's low solubility has been resolved, and isorhamnetin-coomassie brilliant blue G250 now has better biocompatibility. Four different forms of fluorescence compounds' ultraviolet absorption spectra were identified. It was discovered that FC-2, FC-3, and FC-4, respectively, had double peaks at 483-620 nm. FC-4 had the highest ultraviolet absorption intensity, whereas FC-1 exhibited the most consistent and longest wavelength of ultraviolet absorption. Transmission electron microscopy revealed that the acrylic resin evenly disseminated the Coomassie brilliant blue G250-isorhamnetin complex in an amorphous flocculent form. Human prostate cancer cells (PC3) and human cervical cancer cells (HeLa) were investigated in the (Cell Counting Kit-8) CCK8 experiment under 10 different concentration circumstances, and the proliferation impact was 64.30% and 68.06%, respectively. Shown the complex's strong anti-tumor properties and minimal cytotoxicity. Through in vitro imaging of tumor cells, it was found that FC-1's fluorescent complex has high selectivity and can accurately infiltrate tumor cells, proving that it is biocompatible. The design not only addresses the issue of isorhamnein-Coomassie Bright Blue G250's bioavailability, but it also has an effective visual fluorescence targeting effect.

Aggregation-Induced Emission (AIE), Life and Health

Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health.

Conjugated Polymeric Materials in Biological Imaging and Cancer Therapy

Conjugated polymers (CPs) have attracted much attention in the fields of chemistry, medicine, life science, and material science. Researchers have carried out a series of innovative researches and have made significant research progress regarding the unique photochemical and photophysical properties of CPs, expanding the application range of polymers. CPs are polymers formed by the conjugation of multiple repeating light-emitting units. Through precise control of their structure, functional molecules with different properties can be obtained. Fluorescence probes with different absorption and emission wavelengths can be obtained by changing the main chain structure. By modifying the side chain structure with water-soluble groups or selective recognition molecules, electrostatic interaction or specific binding with specific targets can be achieved; subsequently, the purpose of selective recognition can be achieved. This article reviews the research work of CPs in cell imaging, tumor diagnosis, and treatment in recent years, summarizes the latest progress in the application of CPs in imaging, tumor diagnosis, and treatment, and discusses the future development direction of CPs in cell imaging, tumor diagnosis, and treatment.

In Situ Imaging and Anti-inflammation of 3D Printed Scaffolds Enabled by AIEgen

Three-dimensional (3D) printed bioactive scaffolds have been widely used in the field of bone tissue engineering. However, its in vivo visualization and bacterial inflammation are intractable issues during the surgery and treatment. Herein, we first synthesized an aggregation-induced emission-active luminogen (AIEgen) named 4BC with efficient reactive oxygen species (ROS) generation. Then, a series of 3D bioactive scaffolds loaded with 4BC were fabricated by a precipitation adsorption method, namely 4BC@scaffolds, which showed good in situ imaging performance for the implanted scaffolds by using simple UV light irradiation. Among them, the 4BC@TMP scaffold composed of trimagnesium phosphate (TMP) had excellent bactericidal ability for Escherichia coli and Staphylococcus aureus in vitro and resisted bacterial inflammation in vivo through photodynamic action. H&E and immunofluorescence staining were performed to further evaluate the inhibitory effect of bacterial inflammation in vivo. This work verified that AIEgen-based 3D scaffolds are promising bioactive frameworks for bioimaging and antibacterial applications.

Noncancerous disease-targeting AIEgens

Noncancerous diseases include a wide plethora of medical conditions beyond cancer and are a major cause of mortality around the world. Despite progresses in clinical research, many puzzles about these diseases remain unanswered, and new therapies are continuously being sought. The evolution of bio-nanomedicine has enabled huge advancements in biosensing, diagnosis, bioimaging, and therapeutics. The recent development of aggregation-induced emission luminogens (AIEgens) has provided an impetus to the field of molecular bionanomaterials. Following aggregation, AIEgens show strong emission, overcoming the problems associated with the aggregation-caused quenching (ACQ) effect. They also have other unique properties, including low background interferences, high signal-to-noise ratios, photostability, and excellent biocompatibility, along with activatable aggregation-enhanced theranostic effects, which help them achieve excellent therapeutic effects as an one-for-all multimodal theranostic platform. This review provides a comprehensive overview of the overall progresses in AIEgen-based nanoplatforms for the detection, diagnosis, bioimaging, and bioimaging-guided treatment of noncancerous diseases. In addition, it details future perspectives and the potential clinical applications of these AIEgens in noncancerous diseases are also proposed. This review hopes to motivate further interest in this topic and promote ideation for the further exploration of more advanced AIEgens in a broad range of biomedical and clinical applications in patients with noncancerous diseases.

AIE-active macromolecules: designs, performances, and applications

Aggregation-induced emission (AIE) macromolecules as emerging luminescent materials gained increasing attention owing to their good processability, high brightness, wide functionality, and smart responsiveness, with great potential in many fields.

Two-Photon Near-Infrared AIE Luminogens as Multifunctional Gene Carriers for Cancer Theranostics

Construction of multifunctional nonviral gene vectors to execute defined tasks holds great potential for the precise and effective treatment of gene-associated diseases. Herein, we have developed four large π-conjugation triphenylamine derivatives bearing two polar [12]aneN₃ heads and a lipophilic tail for applications in gene delivery, one/two-photon-triggered near-infrared (NIR) fluorescence bioimaging, and combined photodynamic therapy (PDT) and gene therapy of cancer. These compounds possess typical NIR aggregation-induced emission characteristics, mega Stokes shifts, strong two-photon excitation fluorescence, and excellent DNA condensation abilities. Among them, vector 4 with a tail of n-hexadecane realized a transfection efficiency as high as 6.7 times that of the commercial transfection agent Lipofectamine 2000 in HEK293T cell lines. Using vector 4 as an example, transfection process tracking and ex vivo/in vivo tumoral imaging and retention with high resolution, high brightness, deep tissue penetration, and good biosafety were demonstrated. In addition, efficient singlet oxygen (¹O₂) generation by the DNA complex formed by vector 4 (4/DNA) resulted in effective PDT. Combined with anticancer gene therapy, collaborative cancer treatment with a dramatically enhanced cancer cell-killing effect was achieved. The development of this "three birds, one stone" approach suggests a new and promising strategy for better cancer treatment and real-time tracking of gene delivery.

Conjugated Polymers with Aggregation-Induced Emission Characteristics for Fluorescence Imaging and Photodynamic Therapy

Accurate diagnosis and treatment have been extensively developed in the field of biomedicine, which put forward higher requirements for the development of biomedical materials with high efficiency and selectivity. Among them, conjugated polymers featuring aggregation-induced emission (AIE) characteristics (AIE conjugated polymers) have stood out in recent years owing to their unique properties, such as intense solid emission, high light-harvesting ability, efficient energy transfer, and high ¹ O₂ generation ability, which empower them with effective biomedical functions in fluorescence imaging (FLI), photodynamic therapy (PDT), FLI-guided PDT, two-photon excited photodynamic therapy (2PE-PDT), etc. In this review, we highlight recent progress in AIE conjugated polymers and their applications in anticancer and antibacterial areas based on FLI and PDT, and summarize the mechanism of color-tuned fluorescence emission and efficient ¹ O₂ generation ability. The challenges and perspectives for the future development of AIE conjugated polymers are also discussed.

In vivo visualization assay to evaluate the effects of maternal exposure to mercury on offspring bioaccumulation in the oriental river prawn (Macrobrachium nipponense)

Mercury (Hg) is a persistent pollutant that accumulates in aquatic animals. However, studies related to understand how gonad tissue of this species responds to mercury exposure and elucidation of mercury bioaccumulation in crustacean offspring by cross-generational, are still sparse. The present study aimed to assess the bioaccumulation of Hg²⁺in vivo in prawn offspring by a specific aggregation-induced emission fluorogen (AIEgen). The 96 h median lethal concentration (LC₅₀) values of mercury to the juveniles were 0.072 mg/L. Hg²⁺ reduced growth performance, damaged oocyte quality, and inhibited ovary maturation, thus inhibiting gonadal maturation in intact prawns. F1 offspring were exposed to Hg²⁺ by direct transfer from their F0 parents, as shown by the distribution of mercury in gonads and fertilized eggs. In the medium containing oriental river prawn larvae, the Hg²⁺ concentration decreased rapidly, indicating fast initial larval uptake of Hg²⁺. Due to metal ion triggered AIE activity, analysis of fluorescence images showed that prawn offspring accumulated Hg²⁺ via maternal transfer, and there was a relationship among the photoluminescence intensity, the AIEgen concentration, and mercury levels. The quantitative detection of Hg²⁺ absorption from prawn larvae by the AIEgen represents a novel analytical technique to understand the dynamics of Hg²⁺ between maternal and offspring.

A Novel BODIPY Quaternary Ammonium Salt-Based Fluorescent Probe: Synthesis, Physical Properties, and Live-Cell Imaging

The development of biological fluorescent probes is of great significance to the field of cancer bio-imaging. However, most current probes within the bulky hydrophobic group have limited application in aqueous medium and restricted imaging under physiological conditions. Herein, we proposed two efficient molecules to study their physical properties and imaging work, and the absorption and fluorescence intensity were collected with varying ions attending in aqueous medium. We enhance the water solubility through the quaternization reaction and form a balance between hydrophilic and hydrophobicity with dipyrrome-theneboron difluoride (BODIPY) fluorophore. We introduced pyridine and dimethylaminopyridine (DMAP) by quaternization and connected the BODIPY fluorophore by ethylenediamine. The final synthesized probes have achieved ideal affinity with HeLa cells (human cervical carcinoma cell line) in live-cell imaging which could be observed by Confocal Microscope. The probes also have a good affinity with subcutaneous tumor cells in mice in in vivo imaging, which may make them candidates as oncology imaging probes.

Testing active membranes for bone regeneration: A review

OBJECTIVES

Maxillofacial bone defects are the main hindering conditions for traditional dental implant strategies. Guided Bone Regeneration (GBR) is used to handle this situation. The principle of GBR is to use a membrane to prevent the colonization of soft tissue cells of the bone defect and favors the migration of osteogenic linages. Current membranes do not completely fulfill the requirements that an optimal membrane should have, sometimes resulting in non-predictable results. Thus, the need to develop an ideal membrane to perform this duty is clear. Recent developments in bio-manufacturing are driving innovations in membranes technology permitting the active participation of the membrane in the healing and regenerative process trough native tissue mimicking, drug-delivery and cells interaction, away from being a passive barrier. New membranes features need specific evaluation techniques, beyond the International Standard for membrane materials (last reviewed in 2004), being this the rationale for the present review. Nanotechnology application has completely shifted the way of analyzing structural characterization. New progresses on osteoimmmunomodulation have also switched the understanding of cells-membranes interaction.

DATA AND SOURCES

To propose an updated protocol for GBR membranes evaluation, critical reading of the relevant published literature was carried out after a MEDLINE/PubMed database search.

CONCLUSIONS

The main findings are that a potential active membrane should be assessed in its nanostructure, physicochemical and nanomechanical properties, bioactivity and antibacterial, osteoblasts proliferation, differentiation and mineralization. Immunomodulation testing for macrophages recruitment and M2 phenotype promotion in osteoblasts co-culture has to be achieved to completely analyze membranes/tissue interactions.