Multifunctional microcapsules: A theranostic agent for US/MR/PAT multi-modality imaging and synergistic chemo-photothermal osteosarcoma therapy

Biopolymer-based bone scaffold for controlled Pt (IV) prodrug release and synergistic photothermal-chemotherapy and immunotherapy in osteosarcoma

Achieving bone defect repair while preventing tumor recurrence after osteosarcoma surgery has consistently posed a clinical challenge. Local treatment with 3D-printed scaffolds loaded with chemotherapeutic drugs can exert certain effects in tumor inhibition and bone regeneration. However, the non-specific activation of chemotherapeutic drugs leads to high local toxic side effects and the formation of an immunosuppressive tumor microenvironment, thereby limiting their clinical application and therapeutic efficacy. To address this, we designed a Pt (IV) prodrug with low toxicity and minimal side effects, which releases Pt (II) in response to glutathione. This prodrug was grafted onto polydopamine (PDA) through an amidation reaction, resulting in a composite nanomaterial (PDA@Pt) that possesses both photothermal synergistic chemotherapy and immuno-oncological properties. Subsequently, we innovatively employed selective laser sintering technology to incorporate PDA@Pt into a poly (L-lactic acid)/bioactive glass matrix, successfully constructing a composite scaffold with dual anti-tumor and bone repair capabilities. The study revealed that the composite scaffold significantly inhibited the growth of osteosarcoma cells and activated the cGAS-STING pathway by inducing DNA damage, ultimately converting the 'cold tumor' into a 'hot tumor.' Additionally, the composite scaffold could induce osteogenic differentiation of bone marrow mesenchymal stem cells and exhibited excellent bone repair capabilities in vivo.

Combination Using Magnetic Iron Oxide Nanoparticles and Magnetic Field for Cancer Therapy

Iron oxide nanoparticles (MNPs) demonstrate notable benefits in magnetic induction, attributed to their distinctive physical and chemical attributes. Emerging cancer treatment utilizing magnetic fields have also gathered increasing attention in the biomedical field. However, the defects of difficult dispersion and poor biocompatibility of MNPs seriously hinder their application. In order to overcome its inherent defects and maximize the therapeutic potential of MNPs, various functionalized MNPs have been developed, and numerous combined treatment methods based on MNPs have been widely studied. In this review, we compare and analyze the common nanoparticles based on MNPs with different sizes, shapes, and functional modifications. Additionally, we introduced the therapeutic mechanisms of the strategies, such as magnetically controlled targeting, magnetic hyperthermia, and magneto-mechanical effect, which based on the unique magnetic induction capabilities of MNPs. Finally, main challenges of MNPs as smart nanomaterials were also discussed. This review seeks to offer a thorough overview of MNPs in biomedicine and a new sight for their application in tumor treatment.

US/PA/MR multimodal imaging-guided multifunctional genetically engineered bio-targeted synergistic agent for tumor therapy

Focused ultrasound ablation surgery (FUAS) is a minimally invasive treatment option that has been utilized in various tumors. However, its clinical advancement has been hindered by issues such as low safety and efficiency, single image guidance mode, and postoperative tumor residue. To address these limitations, this study aimed to develop a novel multi-functional gas-producing engineering bacteria biological targeting cooperative system. Pulse-focused ultrasound (PFUS) could adjust the ratio of thermal effect to non-thermal effect by adjusting the duty cycle, and improve the safety and effectiveness of treatment.The genetic modification of Escherichia coli (E.coli) involved the insertion of an acoustic reporter gene to encode gas vesicles (GVs), resulting in gas-producing E.coli (GVs-E.coli) capable of targeting tumor anoxia. GVs-E.coli colonized and proliferated within the tumor while the GVs facilitated ultrasound imaging and cooperative PFUS. Additionally, multifunctional cationic polyethyleneimine (PEI)-poly (lactic-co-glycolic acid) (PLGA) nanoparticles (PEI-PLGA/EPI/PFH@Fe3O4) containing superparamagnetic iron oxide (SPIO, Fe3O4), perfluorohexane (PFH), and epirubicin (EPI) were developed. These nanoparticles offered synergistic PFUS, supplementary chemotherapy, and multimodal imaging capabilities.GVs-E.coli effectively directed the PEI-PLGA/EPI/PFH@Fe3O4 to accumulate within the tumor target area by means of electrostatic adsorption, resulting in a synergistic therapeutic impact on tumor eradication.In conclusion, GVs-E.coli-mediated multi-functional nanoparticles can synergize with PFUS and chemotherapy to effectively treat tumors, overcoming the limitations of current FUAS therapy and improving safety and efficacy. This approach presents a promising new strategy for tumor therapy.

Bibliometric and visualized analysis of ultrasound combined with microbubble therapy technology from 2009 to 2023

Background

In recent years, with the rapid advancement of fundamental ultrasonography research, the application of ultrasound in disease treatment has progressively increased. An increasing body of research indicates that microbubbles serve not only as contrast agents but also in conjunction with ultrasound, enhancing cavitation effects and facilitating targeted drug delivery, thereby augmenting therapeutic efficacy. The objective of this study is to explore the current status and prevailing research trends in this field from 2009 to 2023 through bibliometric analysis and to forecast future developmental trajectories.

Methods

We selected the Science Citation Index Expanded (SCI-Expanded) from the Web of Science Core Collection (WOSCC) as our primary data source. On 19 January 2024, we conducted a comprehensive search encompassing all articles and reviews published between 2009 and 2023 and utilized the bibliometric online analysis platform, CiteSpace and VOSviewer software to analyze countries/regions, institutions, authors, keywords, and references, used Microsoft Excel 2021 to visualize the trends of the number of articles published by year.

Results

Between 1 January 2009, and 31 December 2023, 3,326 publications on ultrasound combined with microbubble therapy technology were included. There were a total of 2,846 articles (85.6%) and 480 reviews (14.4%) from 13,062 scholars in 68 countries/regions published in 782 journals. China and the United States emerged as the primary contributors in this domain. In terms of publication output and global institutional collaboration, the University of Toronto in Canada has made the most significant contribution to this field. Professor Kullervo Hynynen has achieved remarkable accomplishments in this area. Ultrasound in Medicine and Biology is at the core of the publishing of research on ultrasound combined with microbubble therapy technology. Keywords such as "sonodynamic therapy," "oxygen," "loaded microbubbles" and "Alzheimer's disease" indicate emerging trends in the field and hold the potential to evolve into significant areas of future investigation.

Conclusion

This study provides a summary of the key contributions of ultrasound combined with microbubble therapy to the field's development over the past 15 years and delves into the historical underpinnings and contemporary trends of ultrasound combined with microbubble therapy technology, providing valuable guidance for researchers.

Interaction of Serum and Plasma Proteins with Polyelectrolyte Microparticles with Core/Shell and Shell-Only Structures

Polyelectrolyte microparticles (MPs) synthesized on calcium carbonate cores are considered a promising basis for new drug delivery systems. It is known that microparticles entering a physiological environment absorb proteins on their surface, which can change the properties of the microparticles and alter their functional activity. This study aimed to compare the compositions of the adsorbed protein layer formed on microparticles with the core/shell and shell structures obtained by layer-by-layer deposition. The difference in the microparticle structure was associated with changes in their surface topography and ζ-potential. These microparticles were incubated with human serum or plasma at 37°C for 24 h. The adsorbed proteins were eluted and analyzed by means of SDS-PAGE. The protein composition of the eluates was determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS); a total of 357 proteins were identified, and 183 of them were detected in all samples. Our results demonstrate that the relative abundance of proteins of different functional groups (immunoglobulins, complement proteins, and apolipoproteins) varied depending on the structure and surface characteristics of the polyelectrolyte microparticles and the incubation medium. Our findings expand the understanding of the influence of the physicochemical properties of the microparticles on their interaction with proteins, which can help to improve the design of microparticles for drug delivery.

Hyperpolarized 129Xe Atoms Sense the Presence of Drug Molecules in Nanohosts Revealed by Magnetic Resonance Imaging

Assessing the effectiveness of nanomedicines involves evaluating the drug content at the target site. Currently, most research focuses on monitoring the signal responses from loaded drugs, neglecting the changes caused by the nanohosts. Here, we propose a strategy to quantitatively evaluate the content of loaded drugs by detecting the signal variations resulting from the alterations in the microenvironment of the nanohosts. Specifically, hyperpolarized (HP) 129Xe atoms are employed as probes to sense the nanohosts' environment and generate a specific magnetic resonance (MR) signal that indicates their accessibility. The introduction of drugs reduces the available space in the nanohosts, leading to a crowded microenvironment that hinders the access of the 129Xe atoms. By employing 129Xe atoms as a signal source to detect the alterations in the microenvironment, we constructed a three-dimensional (3D) map that indicated the concentration of the nanohosts and established a linear relationship to quantitatively measure the drug content within the nanohosts based on the corresponding MR signals. Using the developed strategy, we successfully quantified the uptake of the nanohosts and drugs in living cells through HP 129Xe MR imaging. Overall, the proposed HP 129Xe atom-sensing approach can be used to monitor alterations in the microenvironment of nanohosts induced by loaded drugs and provides a new perspective for the quantitative evaluation of drug presence in various nanomedicines.

Zinc Doping Engineering in ZnxFe3-xO4 Heterostructures for Enhancing Photodynamic Therapy in the Near-Infrared-II Region

Currently, photodynamic therapy (PDT) is restricted by the laser penetration depth. Except for PDT at 1064 nm wavelength excitation, the development of other NIR-II-activated nanomaterials with a higher response depth is still hindered and rarely reported in the literature. To overcome these problems, we fabricated a nanoplatform with heterostructures that generate reactive oxygen species (ROS) and ferrite nanoparticles under a high concentration of zinc doping (ZnxFe3-xO4 NPs), which can achieve oxidative damage of tumor cells under near-infrared (NIR) illumination. The recombination of photoelectrons and holes has been markedly inhibited due to the formation of heterostructures in the interfaces, thus greatly enhancing the capability for ROS and oxygen production by modulating the single-component doping content. The efficiency of PDT was verified by in vivo and in vitro assays under NIR light. Our results revealed that NIR-II (1208 nm) light irradiation of ZnxFe3-xO4 NPs exerted a remarkable antitumor activity, superior to NIR-I light (808 nm). More importantly, the reported ZnxFe3-xO4 NPs strategy provides an opportunity for the success of comparison with light in the first and second near-infrared regions.

Injectable Hydrogels with Integrated Ph Probes and Ultrasound-Responsive Microcapsules as Smart Wound Dressings for Visual Monitoring and On-Demand Treatment of Chronic Wounds

Hydrogel dressings capable of infection monitoring and precise treatment administration show promise for advanced wound care. Existing methods involve embedd ingorganic dyes or flexible electronics into preformed hydrogels, which raise safety issues and adaptability challenges. In this study, an injectable hydrogel based smart wound dressing is developed by integrating food-derived anthocyanidin as a visual pH probe for infection monitoring and poly(L-lactic acid) microcapsules as ultrasound-responsive delivery systems for antibiotics into a poly(ethylene glycol) hydrogel. This straightforwardly prepared hydrogel dressing maintains its favorable properties for wound repair, including porous morphology and excellent biocompatibility. In vitro experiments demonstrated that the hydrogel enabled visual assessment of pH within the range of 5 ∼ 9.Meanwhile, the release of antibiotics could be triggered and controlled by ultrasound. In vivo evaluations using infected wounds and diabetic wounds revealed that the wound dressing effectively detected wound infection by monitoring pH levels and achieved antibacterial effects through ultrasound-triggered drug release. This led to significantly enhanced wound healing, as validated by histological analysis and the measurement of inflammatory cytokine levels. This injectable hydrogel-based smart wound dressing holds great potential for use in clinical settings to inform timely and precise clinical intervention and in community to improve wound care management.

Integrating Fluorescence and Magnetic Resonance Imaging in Biocompatible Scaffold for Real-Time Bone Repair Monitoring and Assessment

In situ monitoring of bone tissue regeneration progression is critical for the development of bone tissue engineering scaffold. However, engineered scaffolds that can stimulate osteogenic progress and allow for non-invasive monitoring of in vivo bone regeneration simultaneously are rarely reported. Based on a hard-and-soft integration strategy, a multifunctional scaffold composed of 3D printed microfilaments and a hydrogel network containing simvastatin (SV), indocyanine green-loaded superamphiphiles, and aminated ultrasmall superparamagnetic iron oxide nanoparticles (USPIO-NH2 ) is fabricated. Both in vitro and in vivo results demonstrate that the as-prepared scaffold significantly promotes osteogenesis through controlled SV release. The biocomposite scaffold exhibits alkaline phosphatase-responsive near-infrared II fluorescence imaging. Meanwhile, USPIO-NH2 within the co-crosslinked nanocomposite network enables the visualization of scaffold degradation by magnetic resonance imaging. Therefore, the biocomposite scaffold enables or facilitates non-invasive in situ monitoring of neo-bone formation and scaffold degradation processes following osteogenic stimulation, offering a promising strategy to develop theranostic scaffolds for tissue engineering.

Efficient Construction of pH-Stimuli-Responsive Colloidosomes with High Encapsulation Efficiency

Intelligent responsive colloidosomes have attracted increasing attention for their potential to enhance the efficacy and decrease the side effects of drugs in biomedical applications. However, a low encapsulation efficiency and complicated preparation method greatly limit their development. Herein, we report an efficient approach for the construction of pH-stimuli-responsive colloidosomes with high encapsulation efficiency by a high-gravity technology. The conditions under which latex particles with different methacrylic acid contents can successfully self-assemble into colloidosomes are explored. During the preparation process, emulsions emulsified for only 10 min at 2500 rpm in a unique high-gravity shearing surroundings are clarified owing to the greatly enhanced micromixing, while the emulsions emulsified for 30 min by a traditional high-speed shear machine at 4000 rpm are still yellow-white. More importantly, regular spherical colloidosomes encapsulating an anticancer drug doxorubicin not only achieve a small mean diameter of 2.82 μm but also realize a high encapsulation efficiency of 76.5%. The release performance of doxorubicin has an obvious pH-stimuli-responsive regularity and follows the first-order model of sustained release. The construction of intelligent responsive colloidosomes as drug carriers provides a route for controlled drug release and biomedical applications.

Theoretical simulation and experimental design of selenium and gold incorporated polymer-based microcarriers for ROS-mediated combined photothermal therapy

Recently, multi-modal combined photothermal therapy (PTT) with the use of photo-active materials has attracted significant attention for cancer treatment. However, drug carriers enabling efficient heating at the tumor site are yet to be designed: this is a fundamental requirement for broad implementation of PTT in clinics. In this work, we design and develop hybrid carriers based on multilayer capsules integrated with selenium nanoparticles (Se NPs) and gold nanorods (Au NRs) to realize reactive oxygen species (ROS)-mediated combined PTT. We show theoretically and experimentally that cooperative interaction of Se NPs with Au NRs improves the heat release efficiency of the developed capsules. In addition, after uptake by tumor cells, intracellular ROS level amplified by Se NPs inhibits the tumor growth. As a consequence, the synergy between Se NPs and Au NRs exhibits the advantages of hybrid carriers such as (i) improved photothermal conversion efficiency and (ii) dual-therapeutic effect. The results of in vitro and in vivo experiments demonstrate that the combination of ROS-mediated therapy and PTT has a higher tumor inhibition efficiency compared to the single-agent treatment (using only Se-loaded or Au-loaded capsules). Furthermore, the developed hybrid carriers show negligible in vivo toxicity towards major organs such as the heart, lungs, liver, kidneys and spleen. This study not only provides a potential strategy for the design of multifunctional "all-in-one" carriers, but also contributes to the development of combined PTT in clinical practice.

Multifunctional nanoparticles for the treatment and diagnosis of osteosarcoma

Osteosarcoma (OS) is a common primary malignant bone tumor in adolescents. Currently, the commonly used treatment strategies for OS include surgery, chemotherapy and radiotherapy. However, these methods have some problems that cannot be ignored, such as postoperative sequelae and severe side effects. Therefore, in recent years, researchers have been looking for other means to improve the treatment or diagnosis effect of OS and increase the overall survival rate of patients. With the development of nanotechnology, nanoparticles (NPs) have presented excellent properties in improving the therapeutic efficacy of drugs for OS. Nanotechnology makes it possible for NPs to combine various functional molecules and drugs to achieve multiple therapeutic effects. This review presents the important properties of multifunctional NPs for the treatment and diagnosis of OS and focuses on the research progress of common NPs applied for drug or gene delivery, phototherapy and diagnosis of OS, such as carbon-based quantum dots, metal, chitosan and liposome NPs. Finally, the promising prospects and challenges of developing multifunctional NPs with enhanced efficacy are discussed, which lays the foundation and direction for improving the future therapeutic and diagnostic methods of OS.

Nanobiotechnological approaches in osteosarcoma therapy: Versatile (nano)platforms for theranostic applications

Constructive achievements in the field of nanobiotechnology and their translation into clinical course have led to increasing attention towards evaluation of their use for treatment of diseases, especially cancer. Osteosarcoma (OS) is one of the primary bone malignancies that affects both males and females in childhood and adolescence. Like other types of cancers, genetic and epigenetic mutations account for OS progression and several conventional therapies including chemotherapy and surgery are employed. However, survival rate of OS patients remains low and new therapies in this field are limited. The purpose of the current review is to provide a summary of nanostructures used in OS treatment. Drug and gene delivery by nanoplatforms have resulted in an accumulation of therapeutic agents for tumor cell suppression. Furthermore, co-delivery of genes and drugs by nanostructures are utilized in OS suppression to boost immunotherapy. Since tumor cells have distinct features such as acidic pH, stimuli-responsive nanoparticles have been developed to appropriately target OS. Besides, nanoplatforms can be used for biosensing and providing phototherapy to suppress OS. Furthermore, surface modification of nanoparticles with ligands can increase their specificity and selectivity towards OS cells. Clinical translation of current findings suggests that nanoplatforms have been effective in retarding tumor growth and improving survival of OS patients.

Recent advances in Prussian blue-based photothermal therapy in cancer treatment

Malignant tumours are a serious threat to human health. Traditional chemotherapy has achieved breakthrough improvements but also has significant detrimental effects, such as the development of drug resistance, immunosuppression, and even systemic toxicity. Photothermal therapy (PTT) is an emerging cancer therapy. Under light irradiation, the phototherapeutic agent converts optical energy into thermal energy and induces the hyperthermic death of target cells. To date, numerous photothermal agents have been developed. Prussian blue (PB) nanoparticles are among the most promising photothermal agents due to their excellent physicochemical properties, including photoacoustic and magnetic resonance imaging properties, photothermal conversion performance, and enzyme-like activity. By the construction of suitably designed PB-based nanotherapeutics, enhanced photothermal performance, targeting ability, multimodal therapy, and imaging-guided cancer therapy can be effectively and feasibly achieved. In this review, the recent advances in PB-based photothermal combinatorial therapy and imaging-guided cancer therapy are comprehensively summarized. Finally, the potential obstacles of future research and clinical translation are discussed.

TCPP/MgO-loaded PLGA microspheres combining photodynamic antibacterial therapy with PBM-assisted fibroblast activation to treat periodontitis

Bacteria eradication and subsequent periodontal tissue reconstruction is the primary task for periodontitis treatment. Commonly used antibiotic therapy suffers from antibiotic resistance. Meanwhile, promoting fibroblast activity is crucial for re-establishing a damaged periodontal structure. In addition to the fibroblast activation property of Mg²⁺, photobiomodulation (PBM) has recently attracted increasing attention in wound healing. Using the same 635 nm laser resource, PBM could simultaneously work with antibacterial photodynamic therapy (aPDT) to achieve antibacterial function and fibroblast activation effect. Herein, multifunctional microspheres were designed by employing poly (lactic-co-glycolic acid) (PLGA) microspheres to load tetrakis (4-carboxyphenyl) porphyrin (TCPP) and magnesium oxide (MgO) nanoparticles, named as PMT, with sustained Mg²⁺ release for 20 days. PMT achieved excellent antibacterial photodynamic effect for periodontal pathogens F. nucleatum and P. gingivalis by generating reactive oxygen species, which increases cell membrane permeability and destroys bacteria integrity to cause bacteria death. Meanwhile, PMT itself exhibited improved fibroblast viability and adhesion, with the PMT + light group revealing further activation of fibroblast cells, suggesting the coordinated action of Mg²⁺ and PBM effects. The underlying molecular mechanism might be the elevated gene expressions of Fibronectin 1, Col1a1, and Vinculin. In addition, the in vivo rat periodontitis model proved the superior therapeutic effects of PMT with laser illumination using micro-computed tomography analysis and histological staining, which presented decreased inflammatory cells, increased collagen production, and higher alveolar bone level in the PMT group. Our study sheds light on a promising strategy to fight periodontitis using versatile microspheres, which combine aPDT and PBM-assisted fibroblast activation functions.

Glucose Oxidase-Modified Metal-Organic Framework for Starving-Enhanced Chemodynamic Therapy

Chemodynamic therapy (CDT) has been considered an emerging strategy for cancer treatment. However, the tumor microenvironment (TME) with slight acidity and restricted H₂O₂ limits the efficacy of CDT. Here, we report a Hf-Mn-TCPP (Hf = hafnium; Mn-TCPP = 5, 10, 15, 20-tetrakis (4-carboxyphenyl) porphyrinato-manganese (II) chloride) loaded with glucose oxidase (GOx) to realize starving-enhanced CDT. GOx consumes glucose to produce H₂O₂ and gluconic acid. Gluconic acid increases the acidity of TME and subsequently provides favorable conditions for the Fenton-like reaction based on Hf-Mn-TCPP. The results indicate that GOx-modified Hf-Mn-TCPP provided a great therapeutic effect in starvation-enhanced CDT in vitro and in vivo.

Advances in Single-component inorganic nanostructures for photoacoustic imaging guided photothermal therapy

Phototheranostic based on photothermal therapy (PTT) and photoacoustic imaging (PAI), as one of avant-garde medical techniques, have sparked growing attention because it allows noninvasive, deeply penetrative, and highly selective and effective therapy. Among a variety of phototheranostic nanoagents, single-component inorganic nanostructures are found to be novel and attractive PAI and PTT combined nanotheranostic agents and received tremendous attention, which not only exhibit structural controllability, high tunability in physiochemical properties, size-dependent optical properties, high reproducibility, simple composition, easy functionalization, and simple synthesis process, but also can be endowed with multiple therapeutic and imaging functions, realizing the superior therapy result along with bringing less foreign materials into body, reducing systemic side effects and improving the bioavailability. In this review, according to their synthetic components, conventional single-component inorganic nanostructures are divided into metallic nanostructures, metal dichalcogenides, metal oxides, carbon based nanostructures, upconversion nanoparticles (UCNPs), metal organic frameworks (MOFs), MXenes, graphdiyne and other nanostructures. On the basis of this category, their detailed applications in PAI guide PTT of tumor treatment are systematically reviewed, including synthesis strategies, corresponding performances, and cancer diagnosis and therapeutic efficacy. Before these, the factors to influence on photothermal effect and the principle of in vivo PAI are briefly presented. Finally, we also comprehensively and thoroughly discussed the limitation, potential barriers, future perspectives for research and clinical translation of this single-component inorganic nanoagent in biomedical therapeutics.

3D printing of bone and cartilage with polymer materials

Damage and degeneration to bone and articular cartilage are the leading causes of musculoskeletal disability. Commonly used clinical and surgical methods include autologous/allogeneic bone and cartilage transplantation, vascularized bone transplantation, autologous chondrocyte implantation, mosaicplasty, and joint replacement. 3D bio printing technology to construct implants by layer-by-layer printing of biological materials, living cells, and other biologically active substances in vitro, which is expected to replace the repair mentioned above methods. Researchers use cells and biomedical materials as discrete materials. 3D bio printing has largely solved the problem of insufficient organ donors with the ability to prepare different organs and tissue structures. This paper mainly discusses the application of polymer materials, bio printing cell selection, and its application in bone and cartilage repair.

Fabrication of a controlled-release delivery system for relieving sciatica nerve pain using an ultrasound-responsive microcapsule

Lidocaine, a potent local anesthetic, is clinically used in nerve block and pain management. However, due to its short half-life, repeated administration is required. For this reason, here we designed and prepared a lidocaine-encapsulated polylactic acid-glycolic acid (Lidocaine@PLGA) microcapsule with ultrasound responsiveness to relieve the sciatica nerve pain. With a premixed membrane emulsification strategy, the fabricated lidocaine-embedded microcapsules possessed uniform particle size, good stability, injectability, and long-term sustained release both in vitro and in vivo. More importantly, Lidocaine@PLGA microcapsules had the function of ultrasonic responsive release, which made the drug release controllable with the effect of on-off administration. Our research showed that using ultrasound as a trigger switch could promote the rapid release of lidocaine from the microcapsules, achieving the dual effects of long-term sustained release and short-term ultrasound-triggered rapid release, which can enable the application of ultrasound-responsive Lidocaine@PLGA microcapsules to nerve root block and postoperative pain relief.

Polydopamine-modified ZIF-8 nanoparticles as a drug carrier for combined chemo-photothermal osteosarcoma therapy

Single chemotherapy often causes severe adverse effects and chemoresistance which limits therapeutic efficacy. Recently, combination of chemotherapy with photothermal therapy (PTT) have received broad attention for synergistic treatment of osteosarcoma, ultimately resulting in the enhancement of therapeutic efficacy of anticancer drugs. In this study, we have developed a novel drug delivery system based on polydopamine (pDA)-modified ZIF-8 nanoparticles loaded with methotrexate (MTX) (pDA/MTX@ZIF-8 NPs). Herein, pDA modification avoided the explosive release of the drug, and improved the biocompatibility and near-infrared (NIR) light absorbance performance of nanoparticles. The as-prepared pDA/MTX@ZIF-8 NPs could be used as drug targeting delivery system and simultaneously displayed excellent photothermal effects under NIR irradiation. Biology assays in vitro indicated that the pDA/MTX@ZIF-8 NPs were able to efficiently induce MG63 cell apoptosis through reducing mitochondrial membrane potentials (MMPs), and the introduction of photothermal agents enhanced the antitumor effect and decreased the dose of chemotherapeutic drugs. Moreover, the optimized pDA/MTX@ZIF-8 NPs (40 μg/mL) exhibited better photothermal conversion performance and facilitated tumor cells death. These results triumphantly exhibit that the pDA/MTX@ZIF-8 NPs have a synergistic effect of chemo-photothermal therapy (combination index CI = 0.346) and excellent biocompatibility, which has unexceptionable prospects for the therapy of osteosarcoma.

A simple, universal and multifunctional template agent for personalized treatment of bone tumors

Bone tumors occur in bone or its accessory tissues. Benign bone tumors are easy to cure and have good prognosis, while malignant bone tumors develop rapidly and have poor and high mortality. So far, there is no satisfactory treatment method. Here, we designed a universal template vector for bone tumor therapy that simultaneously meets the needs of bone targeting, tumor killing, osteoclast suppression, and tumor imaging. The template is composed of a polydopamine (PDA) core and a multifunctional surface. PDA has excellent biosafety and photothermal performance. In this study, alendronate sodium (ALN) is grafted to enable its general bone targeting function. PDA core can carry a variety of chemotherapy drugs, and the rich ALN group can carry a variety of metal ions with an imaging function. Therefore, more personalized treatment plans can be designed for different bone tumor patients. In addition, the PDA core enables photothermal therapy and enhanced chemotherapy. Through template drug Doxorubicin (DOX) and template imaging ion Fe (Ⅱ), we systematically verified the therapeutic effect, imaging effect, and inhibition of bone dissolution of the agent on Osteosarcoma (OS), a primary malignant bone tumor, in vivo. In conclusion, our work provides a more general template carrier for the clinical treatment of bone tumors, through which personalized treatment of bone tumors can be achieved.

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The PDA-ALN-DOX presented high bone targeting property, photothermal conversion efficiency, drug loading capacity, and multimodal imaging modalities.

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CPT is a more efficient and convenient therapy for bone tumors.

Design and aligner-assisted fast fabrication of a microfluidic platform for quasi-3D cell studies on an elastic polymer

While most studies of mechanical stimulation of cells are focused on two-dimensional (2D) and three-dimensional (3D) systems, it is rare to study the effects of cyclic stretching on cells under a quasi-3D microenvironment as a linkage between 2D and 3D. Herein, we report a new method to prepare an elastic membrane with topographic microstructures and integrate the membrane into a microfluidic chip. The fabrication difficulty lay not only in the preparation of microstructures but also in the alignment and bonding of the patterned membrane to other layers. To resolve the problem, we designed and assembled a fast aligner that is cost-effective and convenient to operate. To enable quasi-3D microenvironment of cells, we fabricated polydimethylsiloxane (PDMS) microwell arrays (formed by micropillars of a few microns in diameter) with the microwell diameters close to the cell sizes. An appropriate plasma treatment was found to afford a coating-free approach to enable cell adhesion on PDMS. We examined three types of cells in 2D, quasi-3D, and 3D microenvironments; the cell adhesion results showed that quasi-3D cells behaved between 2D and 3D cells. We also constructed transgenic human mesenchymal stem cells (hMSCs); under cyclic stretching, the visualizable live hMSCs in microwells were found to orientate differently from in a 3D Matrigel matrix and migrate differently from on a 2D flat plate. This study not only provides valuable tools for microfabrication of a microfluidic device for cell studies, but also inspires further studies of the topological effects of biomaterials on cells.

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A microfluidic platform for quasi-3D cell studies was presented as a linkage between 2D and 3D cell-material research systems.

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The fabrication difficulty was overcome by designing an effective aligner that can be easily assembled.

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Cell behaviors can be enhanced with a proper quasi-3D biomaterial microenvironment.

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A new transgenic cell line and systematic 3D approaches were developed to visualize and digitalize the quasi-3D cells.

Advances of Hydrogel-Based Bioprinting for Cartilage Tissue Engineering

Bioprinting has gained immense attention and achieved the revolutionized progress for application in the multifunctional tissue regeneration. On account of the precise structural fabrication and mimicking complexity, hydrogel-based bio-inks are widely adopted for cartilage tissue engineering. Although more and more researchers have reported a number of literatures in this field, many challenges that should be addressed for the development of three-dimensional (3D) bioprinting constructs still exist. Herein, this review is mainly focused on the introduction of various natural polymers and synthetic polymers in hydrogel-based bioprinted scaffolds, which are systematically discussed via emphasizing on the fabrication condition, mechanical property, biocompatibility, biodegradability, and biological performance for cartilage tissue repair. Further, this review describes the opportunities and challenges of this 3D bioprinting technique to construct complex bio-inks with adjustable mechanical and biological integrity, and meanwhile, the current possible solutions are also conducted for providing some suggestive ideas on developing more advanced bioprinting products from the bench to the clinic.

Endogenous microRNA triggered enzyme-free DNA logic self-assembly for amplified bioimaging and enhanced gene therapy via in situ generation of siRNAs

BACKGROUND

Small interfering RNA (siRNA) has emerged as a kind of promising therapeutic agents for cancer therapy. However, the off-target effect and degradation are the main challenges for siRNAs delivery. Herein, an enzyme-free DNA amplification strategy initiated by a specific endogenous microRNA has been developed for in situ generation of siRNAs with enhanced gene therapy effect on cervical carcinoma.

METHODS

This strategy contains three DNA hairpins (H1, H2/PS and H3) which can be triggered by microRNA-21 (miR-21) for self-assembly of DNA nanowheels (DNWs). Notably, this system is consistent with the operation of a DNA logic circuitry containing cascaded "AND" gates with feedback mechanism. Accordingly, a versatile biosensing and bioimaging platform is fabricated for sensitive and specific analysis of miR-21 in HeLa cells via fluorescence resonance energy transfer (FRET). Meanwhile, since the vascular endothelial growth factor (VEGF) antisense and sense sequences are encoded in hairpin reactants, the performance of this DNA circuit leads to in situ assembly of VEGF siRNAs in DNWs, which can be specifically recognized and cleaved by Dicer for gene therapy of cervical carcinoma.

RESULTS

The proposed isothermal amplification approach exhibits high sensitivity for miR-21 with a detection limit of 0.25 pM and indicates excellent specificity to discriminate target miR-21 from the single-base mismatched sequence. Furthermore, this strategy achieves accurate and sensitive imaging analysis of the expression and distribution of miR-21 in different living cells. To note, compared to naked siRNAs alone, in situ siRNA generation shows a significantly enhanced gene silencing and anti-tumor effect due to the high reaction efficiency of DNA circuit and improved delivery stability of siRNAs.

CONCLUSIONS

The endogenous miRNA-activated DNA circuit provides an exciting opportunity to construct a general nanoplatform for precise cancer diagnosis and efficient gene therapy, which has an important significance in clinical translation.