Silica nanocarrier-mediated intracellular delivery of rapamycin promotes autophagy-mediated M2 macrophage polarization to regulate bone regeneration

A biomimetic nanomedicine alleviates liver transplant-related biliary injury by sequentially inhibiting oxidative stress and regulating macrophage polarization via Nrf-2/HO-1 and JNK pathways

Liver transplantation is an effective method for treating end-stage liver disease. However, 10-20 % of liver transplantation patients develop biliary injury, the main cause of which is ischemia-reperfusion injury (IRI), which consists of oxidative stress injury in the early stage and inflammatory injury in the advanced stage. Biliary injury seriously affects patient outcomes and even leads to mortality, and there are few effective treatments for IRI. Herein, nanoparticles containing quercetin (QR) and rapamycin (RP) coated with poly (lactic-co-glycolic acid) (PLGA) and encapsulated by platelet membrane (PM) were designed to treat IRI in the liver transplantation. The specific binding of ICAM-1 expressed on the PM to integrins (e.g., LFA-1 and Mac-1) in damaged vascular endothelial cells, as well as the interaction between P-selectin on the platelet surface and PSGL-1 on the macrophage surface, allows the accumulation of these biomimetic cell membrane-encapsulated nanoparticles, and subsequently, the delivery of both drugs, to ischemia-reperfusion sites in the liver. The encapsulated QR alleviated oxidative stress injury by activating the Nrf-2/HO-1 signaling pathway in the early stage in model rats with IRI and liver transplantation models. Moreover, RP alleviated inflammatory damage in the advanced stage by suppressing the JNK signaling pathway in M1 macrophages. Thus, these biomimetic nanoparticles that intervene in IRI to alleviate both the early oxidative stress and the advanced inflammatory response constitute a novel delivery system for managing biliary injury after liver transplantation.

A novel approach for the co-delivery of 5-fluorouracil and everolimus for breast cancer combination therapy: stimuli-responsive chitosan hydrogel embedded with mesoporous silica nanoparticles

BACKGROUND

Breast cancer remains one of the leading causes of death among women globally, with traditional therapies often limited by challenges such as drug resistance and significant side effects. Combination therapies, coupled with nanotechnology-based co-delivery systems, offer enhanced efficacy by targeting multiple pathways in cancer progression. In this study, we developed an injectable, stimuli-responsive nanosystem using a chitosan hydrogel embedded with mesoporous silica nanoparticles for the co-administration of 5-fluorouracil and everolimus. This approach aims to optimize controlled drug release, enhance the synergistic anticancer effect, and overcome challenges associated with co-loading different therapeutic agents.

METHODS

Various techniques were employed to characterize the nanoparticles and the hydrogel. Cell uptake, apoptosis, and proliferation of 4T1 breast cancer cells were evaluated by flow cytometry and Resazurin assay, respectively. The Balb/C mice model of breast cancer, which received the therapeutical nanoplatforms subcutaneously near the tumoral region was used to examine tumor size and lung metastases.

RESULTS

The results revealed that the nanoparticles had a suitable loading capacity and high cellular uptake. The drug release was pH-sensitive and synergistic. By incorporating nanoparticles into the hydrogel, the cell death rate and apoptosis of 4T1 breast cancer cells increased significantly, due to the synergistic effects of co-delivered drugs. Additionally, the combination treatment groups showed a significant reduction in tumor size and lung metastasis compared to the monotherapy and control groups.

CONCLUSIONS

These findings underscore the potential of the nanocomposite used to develop a novel co-delivery system to enhance therapeutic outcomes, reduce side effects, and provide a promising new strategy for future cancer treatments.

Ginseng exosomes modulate M1/M2 polarisation by activating autophagy and target IKK/IкB/NF-кB to alleviate inflammatory bowel disease

BACKGROUND

Exosomes are involved in intercellular communication and regulation of the inflammatory microenvironment. In a previous study, we demonstrated that fresh ginseng exosomes (GEs) alleviated inflammatory bowel disease. However, the precise mechanism by which GEs activate the immune system and subsequently inhibit the formation of intestinal inflammatory microenvironment remains unknown.

METHODS

Herein, we investigated the effects of GEs on autophagy, macrophage polarisation, intestinal inflammation, and the epithelial barrier by means of transcriptome sequencing, network pharmacology, transmission electron microscopy, immunoblotting, flow cytometry and small molecule inhibitors.

RESULTS

GEs significantly activated autophagy and M2-like macrophage polarisation, which could be blocked by the autophagy inhibitor 3-methyladenine. In the co-culture system of macrophages and intestinal epithelial cells, macrophages treated with GEs secreted more interleukin-10 (IL-10) and significantly reduced Nitric oxide (NO) levels in intestinal epithelial cells in vitro. Furthermore, GEs acted directly on intestinal epithelial cells through the IKK/IкB/NF-кB signalling pathway to reduce inflammation and restore the intestinal barrier. Orally administered GEs could restore disrupted colonic barriers, alleviate inflammatory bowel responses, and regulate the polarisation of intestinal macrophages in vivo.

CONCLUSION

In summary, GEs may be a potential treatment for inflammatory bowel disease, and targeting autophagy and macrophage polarisation may help alleviate intestinal inflammation.

Palladium-Based Nanocomposites Remodel Osteoporotic Microenvironment by Bone-Targeted Hydrogen Enrichment and Zincum Repletion

Osteoporosis presents a marked global public health challenge, characterized by deficient osteogenesis and a deteriorating immune microenvironment. Conventional clinical interventions primarily target osteoclast-mediated bone damage, yet lack a comprehensive therapeutic approach that balances bone formation and resorption. Herein, we introduce a bone-targeted nanocomposite, A-Z@Pd(H), designed to address these challenges by integrating diverse functional components. The nanocomposite incorporates internal hydrogen-carrying nanozymes, which effectively scavenge multiple reactive oxygen species (ROS) and synergistically engage the autophagy-lysosome pathway to accelerate endogenous ROS degradation in macrophages. This mechanism disrupts the vicious cycle of autophagic dysfunction-ROS accumulation-macrophage inflammation. In addition, external metal-organic frameworks release zinc ions (Zn2+) in response to the acidic osteoporotic environment, thereby promoting osteogenesis. In a murine model of osteoporosis, intravenous administration of A-Z@Pd(H) leads to preferential accumulation in the femur, thereby remodeling the osteoporotic microenvironment through immune regulation, osteogenesis promotion, and osteoclast inhibition. These findings suggest that this system composed of hydrogen therapy and ion therapy may be a promising candidate for bone-targeted comprehensive therapy in osteoporosis.

Immunomodulatory potential of rapamycin-loaded mesoporous silica nanoparticles: pore size-dependent drug loading, release, and in vitro cellular responses

Rapamycin is a potent immunosuppressive drug that has been recently proposed for a wide range of applications beyond its current clinical use. For some of these proposed applications, encapsulation in nanoparticles is key to ensure therapeutic efficacy and safety. In this work, we evaluate the effect of pore size on mesoporous silica nanoparticles (MSN) as rapamycin nanocarriers. The successful preparation of MSN with 4 different pore sizes was confirmed by dynamic light scattering, zeta potential, transmission electron microscopy and N2 adsorption. In these materials, rapamycin loading was pore size-dependent, with smaller pore MSN exhibiting greater loading capacity. Release studies showed sustained drug release from all MSN types, with larger pore MSN presenting faster release kinetics. In vitro experiments using the murine dendritic cell (DC) line model DC2.4 showed that pore size influenced the biological performance of MSN. MSN with smaller pore sizes presented larger nanoparticle uptake by DC2.4 cells, but were also associated with slightly larger cytotoxicity. Further evaluation of DC2.4 cells incubated with rapamycin-loaded MSN also demonstrated a significant effect of MSN pore size on their immunological response. Notably, the combination of rapamycin-loaded MSN with an inflammatory stimulus (lipopolysaccharide, LPS) led to changes in the expression of DC activation markers (CD40 and CD83) and in the production of the proinflammatory cytokine TNF-α compared to LPS-treated DC without nanoparticles. Smaller-pored MSN induced more substantial reductions in CD40 expression while eliciting increased CD83 expression, indicating potential immunomodulatory effects. These findings highlight the critical role of MSN pore size in modulating rapamycin loading, release kinetics, cellular uptake, and subsequent immunomodulatory responses.

Revolutionizing lymph node metastasis imaging: the role of drug delivery systems and future perspectives

The deployment of imaging examinations has evolved into a robust approach for the diagnosis of lymph node metastasis (LNM). The advancement of technology, coupled with the introduction of innovative imaging drugs, has led to the incorporation of an increasingly diverse array of imaging techniques into clinical practice. Nonetheless, conventional methods of administering imaging agents persist in presenting certain drawbacks and side effects. The employment of controlled drug delivery systems (DDSs) as a conduit for transporting imaging agents offers a promising solution to ameliorate these limitations intrinsic to metastatic lymph node (LN) imaging, thereby augmenting diagnostic precision. Within the scope of this review, we elucidate the historical context of LN imaging and encapsulate the frequently employed DDSs in conjunction with a variety of imaging techniques, specifically for metastatic LN imaging. Moreover, we engage in a discourse on the conceptualization and practical application of fusing diagnosis and treatment by employing DDSs. Finally, we venture into prospective applications of DDSs in the realm of LNM imaging and share our perspective on the potential trajectory of DDS development.

Chitosan-Rapamycin Carbon Dots Alleviate Glaucomatous Retinal Injury by Inducing Autophagy to Promote M2 Microglial Polarization

Introduction

Glaucoma is a prevalent cause of irreversible vision impairment, characterized by progressive retinal ganglion cells (RGCs) loss, with no currently available effective treatment. Rapamycin (RAPA), an autophagy inducer, has been reported to treat glaucoma in rodent models by promoting RGC survival, but its limited water solubility, systemic toxicity, and pre-treatment requirements hinder its potential clinical applications.

Methods

Chitosan (CS)-RAPA carbon dot (CRCD) was synthesized via hydrothermal carbonization of CS and RAPA and characterized by transmission electron microscopy, Fourier transform infrared spectra, and proton nuclear magnetic resonance. In vitro assays on human umbilical cord vein endothelial and rat retinal cell line examined its biocompatibility and anti-oxidative capabilities, while lipopolysaccharide-stimulated murine microglia (BV2) assays measured its effects on microglial polarization. In vivo, using a mouse retinal ischemia/reperfusion (I/R) model by acute intraocular pressure elevation, the effects of CRCD on visual function, RGC apoptosis, oxidative stress, and M2 microglial polarization were examined.

Results

CRCD exhibited good water solubility and anti-oxidative capabilities, in the form of free radical scavenging. In vitro, CRCD was bio-compatible and lowered oxidative stress, which was also found in vivo in the retinal I/R model. Additionally, both in vitro with lipopolysaccharide-stimulated BV2 cells and in vivo with the I/R model, CRCD was able to promote M2 microglial polarization by activating autophagy, which, in turn, down-regulated pro-inflammatory cytokines, such as IL-1β and TNF-α, as well as up-regulated anti-inflammatory cytokines, such as IL-4 and TGF-β. All these anti-oxidative and anti-inflammatory effects ultimately aided in preserving RGCs, and subsequently, improved visual function.

Discussion

CRCD could serve as a potential novel treatment strategy for glaucoma, via incorporating RAPA into CDs, in turn not only mitigating its toxic side effects but also enhancing its therapeutic efficacy.

Nanoparticles Internalization through HIP-55-Dependent Clathrin Endocytosis Pathway

Nanoparticles are promising tools for biomedicine. Many nanoparticles are internalized to function. Clathrin-mediated endocytosis is one of the most important mechanisms for nanoparticle internalization. However, the regulatory mechanism of clathrin-mediated nanoparticle endocytosis is still unclear. Here, we report that the adapter protein HIP-55 regulates clathrin-mediated nanoparticle endocytosis. CdSe/ZnS quantum dots (QDs), a typical nanoparticle, enter cells through the HIP-55-dependent clathrin endocytosis pathway. Both pharmacological inhibitor and genetic intervention demonstrate that QDs enter cells through clathrin-mediated endocytosis. HIP-55 can interact with clathrin and promote clathrin-mediated QDs endocytosis. Furthermore, HIP-55 ΔADF which is defective in F-actin binding fails to promote QDs endocytosis, indicating HIP-55 promotes clathrin-mediated QDs endocytosis depending on interaction with F-actin. In vivo, HIP-55 knockout also inhibits endocytosis of QDs. These findings reveal that HIP-55 acts as an intrinsic regulator for clathrin-mediated nanoparticle endocytosis, providing new insight into the nanoparticle internalization and a new strategy for nanodrug enrichment in target cells.

Nanocomposites based on nanoceria regulate the immune microenvironment for the treatment of polycystic ovary syndrome

The immune system is closely associated with the pathogenesis of polycystic ovary syndrome (PCOS). Macrophages are one of the important immune cell types in the ovarian proinflammatory microenvironment, and ameliorate the inflammatory status mainly through M2 phenotype polarization during PCOS. Current therapeutic approaches lack efficacy and immunomodulatory capacity, and a new therapeutic method is needed to prevent inflammation and alleviate PCOS. Here, octahedral nanoceria nanoparticles with powerful antioxidative ability were bonded to the anti-inflammatory drug resveratrol (CeO2@RSV), which demonstrates a crucial strategy that involves anti-inflammatory and antioxidative efficacy, thereby facilitating the proliferation of granulosa cells during PCOS. Notably, our nanoparticles were demonstrated to possess potent therapeutic efficacy via anti-inflammatory activities and effectively alleviated endocrine dysfunction, inflammation and ovarian injury in a dehydroepiandrosterone (DHEA)-induced PCOS mouse model. Collectively, this study revealed the tremendous potential of the newly developed nanoparticles in ameliorating the proinflammatory microenvironment and promoting the function of granulosa cells, representing the first attempt to treat PCOS by using CeO2@RSV nanoparticles and providing new insights in combating clinical PCOS.

Microenvironment-Regulating Drug Delivery Nanoparticles for Treating and Preventing Typical Biofilm-Induced Oral Diseases

The oral cavity comprises an environment full of microorganisms. Dysregulation of this microbial-cellular microenvironment will lead to a series of oral diseases, such as implant-associated infection caused by Staphylococcus aureus (S. aureus) biofilms and periodontitis initiated by Streptococcus oralis (S. oralis). In this study, a liposome-encapsulated indocyanine green (ICG) and rapamycin drug-delivery nanoparticle (ICG-rapamycin) is designed to treat and prevent two typical biofilm-induced oral diseases by regulating the microbial-cellular microenvironment. ICG-rapamycin elevates the reactive oxygen species (ROS) and temperature levels to facilitate photodynamic and photothermal mechanisms under near-infrared (NIR) laser irradiation for anti-bacteria. In addition, it prevents biofilm formation by promoting bacterial motility with increasing the ATP levels. The nanoparticles modulate the microbial-cellular interaction to reduce cellular inflammation and enhance bacterial clearance, which includes promoting the M2 polarization of macrophages, upregulating the anti-inflammatory factor TGF-β, and enhancing the bacterial phagocytosis of macrophages. Based on these findings, ICG-rapamycin is applied to implant-infected and periodontitis animal models to confirm the effects in vivo. This study demonstrates that ICG-rapamycin can treat and prevent biofilm-induced oral diseases by regulating the microbial-cellular microenvironment, thus providing a promising strategy for future clinical applications.

Autophagy and Biomaterials: A Brief Overview of the Impact of Autophagy in Biomaterial Applications

Macroautophagy (hereafter autophagy), a tightly regulated physiological process that obliterates dysfunctional and damaged organelles and proteins, has a crucial role when biomaterials are applied for various purposes, including diagnosis, treatment, tissue engineering, and targeted drug delivery. The unparalleled physiochemical properties of nanomaterials make them a key component of medical strategies in different areas, such as osteogenesis, angiogenesis, neurodegenerative disease treatment, and cancer therapy. The application of implants and their modulatory effects on autophagy have been known in recent years. However, more studies are necessary to clarify the interactions and all the involved mechanisms. The advantages and disadvantages of nanomaterial-mediated autophagy need serious attention in both the biological and bioengineering fields. In this mini-review, the role of autophagy after biomaterial exploitation and the possible related mechanisms are explored.

Research Hotspots and Trends of Bone Xenograft in Clinical Procedures: A Bibliometric and Visual Analysis of the Past Decade

BACKGROUND

Bone defect therapy is a common clinical challenge for orthopedic and clinical physicians worldwide, and the therapeutic effect affects the physiological function and healthy life quality of millions of patients. Compared with traditional autogenous bone transplants, bone xenografts are attracting attention due to their advantages of unlimited availability and avoidance of secondary damage. However, there is currently a lack of bibliometric analysis on bone xenograft. This study aimed to use bibliometric methods to analyze the literature on bone xenograft from 2013 to 2023, to explore the current status, hotspots, and future trends of research in this field, and to promote its development and progress.

METHODS

Using the Web of Science Core Collection database, we retrieved and collected publication data related to xenogeneic bone grafting materials worldwide from January 2013 to March 2023. Origin (2021), CiteSpace (6.2.R2 standard), and an online bibliometric platform were used for bibliometric analysis and data visualization.

RESULTS

A total of 3395 documents were retrieved, and 686 eligible papers were selected. The country and institutions with the highest number of publications and centrality were the United States (125 papers, centrality = 0.44) and the University of Zurich (29 papers, centrality = 0.28), respectively. The most cited author was Araujo MG (163 times), and the author with the most significant centrality was Froum SJ (centrality = 0.09). The main keyword clusters were "tissue engineering", "sinus floor elevation", "dental implants", "tooth extraction", and "bone substitutes". The most significant bursting keywords in the last three years were "platelet rich fibrin".

CONCLUSIONS

Research on bone xenograft is steadily growing and will continue to rise. Currently, research hotspots and directions are mainly focused on dental implants related to bone-augmentation techniques and bone tissue engineering. In the future, research hotspots and directions may focus on decellularization technology and investigations involving platelet-rich fibrin.