Dual targeted zeolitic imidazolate framework nanoparticles for treating metastatic breast cancer and inhibiting bone destruction

Learn from orientation prior for radiograph super-resolution: Orientation operator transformer

BACKGROUND AND OBJECTIVE

High-resolution radiographic images play a pivotal role in the early diagnosis and treatment of skeletal muscle-related diseases. It is promising to enhance image quality by introducing single-image super-resolution (SISR) model into the radiology image field. However, the conventional image pipeline, which can learn a mixed mapping between SR and denoising from the color space and inter-pixel patterns, poses a particular challenge for radiographic images with limited pattern features. To address this issue, this paper introduces a novel approach: Orientation Operator Transformer - O2former.

METHODS

We incorporate an orientation operator in the encoder to enhance sensitivity to denoising mapping and to integrate orientation prior. Furthermore, we propose a multi-scale feature fusion strategy to amalgamate features captured by different receptive fields with the directional prior, thereby providing a more effective latent representation for the decoder. Based on these innovative components, we propose a transformer-based SISR model, i.e., O2former, specifically designed for radiographic images.

RESULTS

The experimental results demonstrate that our method achieves the best or second-best performance in the objective metrics compared with the competitors at ×4 upsampling factor. For qualitative, more objective details are observed to be recovered.

CONCLUSIONS

In this study, we propose a novel framework called O2former for radiological image super-resolution tasks, which improves the reconstruction model's performance by introducing an orientation operator and multi-scale feature fusion strategy. Our approach is promising to further promote the radiographic image enhancement field.

Nanoparticles for the Treatment of Bone Metastasis in Breast Cancer: Recent Advances and Challenges

Although the frequency of bone metastases from breast cancer has increased, effective treatment is lacking, prompting the development of nanomedicine, which involves the use of nanotechnology for disease diagnosis and treatment. Nanocarrier drug delivery systems offer several advantages over traditional drug delivery methods, such as higher reliability and biological activity, improved penetration and retention, and precise targeting and delivery. Various nanoparticles that can selectively target tumor cells without causing harm to healthy cells or organs have been synthesized. Recent advances in nanotechnology have enabled the diagnosis and prevention of metastatic diseases as well as the ability to deliver complex molecular "cargo" particles to metastatic regions. Nanoparticles can modulate systemic biodistribution and enable the targeted accumulation of therapeutic agents. Several delivery strategies are used to treat bone metastases, including untargeted delivery, bone-targeted delivery, and cancer cell-targeted delivery. Combining targeted agents with nanoparticles enhances the selective delivery of payloads to breast cancer bone metastatic lesions, providing multiple delivery advantages for treatment. In this review, we describe recent advances in nanoparticle development for treating breast cancer bone metastases.

Zeolite imidazolate framework-8 in bone regeneration: A systematic review

Zeolite imidazolate framework-8 (ZIF-8) is a biomaterial that has been increasingly studied in recent years. It has several applications such as bone regeneration, promotion of angiogenesis, drug loading, and antibacterial activity, and exerts multiple effects to deal with various problems in the process of bone regeneration. This systematic review aims to provide an overview of the applications and effectiveness of ZIF-8 in bone regeneration. A search of papers published in the PubMed, Web of Science, Embase, and Cochrane Library databases revealed 532 relevant studies. Title, abstract, and full-text screening resulted in 39 papers being included in the review, including 39 in vitro and 22 animal studies. Appropriate concentrations of nano ZIF-8 can promote cell proliferation and osteogenic differentiation by releasing Zn2+ and entering the cell, whereas high doses of ZIF-8 are cytotoxic and inhibit osteogenic differentiation. In addition, five studies confirmed that ZIF-8 exhibits good vasogenic activity. In all in vivo experiments, nano ZIF-8 promoted bone formation. These results indicate that, at appropriate concentrations, materials containing ZIF-8 promote bone regeneration more than materials without ZIF-8, and with characteristics such as promoting angiogenesis, drug loading, and antibacterial activity, it is expected to show promising applications in the field of bone regeneration. STATEMENT OF SIGNIFICANCE: This manuscript reviewed the use of ZIF-8 in bone regeneration, clarified the biocompatibility and effectiveness in promoting bone regeneration of ZIF-8 materials, and discussed the possible mechanisms and factors affecting its promotion of bone regeneration. Overall, this study provides a better understanding of the latest advances in the field of bone regeneration of ZIF-8, serves as a design guide, and contributes to the design of future experimental studies.

Hierarchically Released Liquid Metal Nanoparticles for Mild Photothermal Therapy/Chemotherapy of Breast Cancer Bone Metastases via Remodeling Tumor Stromal Microenvironment

Currently, the treatment strategy for bone metastasis is mainly to inhibit the growth of tumor cells and the activity of osteoclasts, while ignoring the influence of the tumor stromal microenvironment (TSM) on the progression of bone metastasis. Herein, a dual-target liquid metal (LM)-based drug delivery system (DDS) with favorable photothermal performance is designed to spatially program the delivery of multiple therapeutic agents to enhance the treatment of bone metastasis through TSM remodeling. Briefly, mesoporous silicon-coated LM is integrated into zeolitic imidazolate framework-8 (ZIF-8) with both bone-seeking and tumor-targeting capacities. Curcumin (Cur), a tumor microenvironment modulator, is encapsulated into ZIF-8, and doxorubicin (DOX) is enclosed inside mesoporous silicon. Specific accumulation of the LM-based DDS in bone metastases first relieves the tumor stroma by releasing Cur in response to the acidic tumor microenvironment and then releases DOX deep into the tumor under near-infrared light irradiation. The combined strategy of the LM-based DDS and mild photothermal therapy has been shown to effectively restrain cross-talk between osteoclasts and tumor cells by inhibiting the secretion of transforming growth factor-β, degrading extracellular matrix components, and increasing infiltration of CD4+ and CD8+ T cells, which provides a promising strategy for the treatment of bone metastases.

Engineering a facile and versatile nanoplatform to facilitate the delivery of multiple agents for targeted breast cancer chemo-immunotherapy

There is growing evidence showing that single administration of immunotherapeutic agents has limited efficacy in a number of cancer patients mainly due to tumor heterogeneity and immunosuppressive tumor microenvironment. In this study, a novel nanoparticle-based strategy was applied to achieve efficient tumor-targeted therapy by combining chemotherapeutic agents, i.e., doxorubicin (Dox) and melittin (Mel), with an immune checkpoint inhibitor (PD-L1 DsiRNA). The proposed nanoparticle was prepared by the formation of a complex between Mel and PD-L1 DsiRNA (Dicer-substrate short-interfering RNA), followed by the loading of Dox. The surface of the resultant particles (DoxMel/PD-L1 DsiRNA) was then modified with hyaluronic acid (HA) to increase their stability and distribution. In addition, HA can also act as a tumor-targeting agent through binding to its receptor CD44 on the surface of cancer cells. We demonstrated that the surface engineering of DoxMel/PD-L1 DsiRNA with HA significantly enhances its specificity towards breast cancer cells. Moreover, we observed a noticeable reduction in PD-L1 expression together with a synergistic effect of Dox and Mel on killing cancer cells and inducing immunogenic cell death, leading to significantly diminished tumor growth in 4T1-breast tumor bearing Balb/c mice, improved survival rate and extensive infiltration of immune cells including cytotoxic T cells into the tumor microenvironment. Safety analysis revealed that there is no significant toxicity associated with the developed nanoparticle. All in all, the proposed targeted combination treatment strategy can be considered as a useful method to reduce cancer-associated mortality.

Combining dual-targeted liquid metal nanoparticles with autophagy activation and mild photothermal therapy to treat metastatic breast cancer and inhibit bone destruction

Although mild photothermal therapy (mild-PTT) avoids treatment bottleneck of the traditional PTT, the application of mild-PTT in deep and internal tumors is severely restricted due to thermal resistance, limited irradiation area and penetration depth. In addition, bone resorption caused by tumor colonization in distal bone tissue exacerbates tumor progression. Here, a strategy was developed for the treatment of bone metastasis and alleviation of bone resorption, which was based on liquid metal (LM) nanoparticle to resist thermal resistance induced by mild-PTT via autophagy activation. Briefly, LM and autophagy activator (Curcumin, Cur) were loaded into zeolitic imidazolate framework-8 (ZIF-8), which was then functionalized with hyaluronic acid/alendronate (CLALN). CLALN exhibited good photothermal performance, drug release ability under acidic environment, specifical recognition and aggregation at bone metastasis sites. CLALN combined with mild-PPT dramatically inhibited tumor progress by inducing the impaired autophagy and reduced the expression of programmed cell death ligand 1 (PD-L1) protein triggered by mild-PTT, resisting thermal resistance and alleviating the immunosuppression. Besides, CLALN combined with mild-PPT effectively alleviated osteolysis compared with only CLALN or mild-PPT. Our experiments demonstrated that this multi-functional LM-based nanoparticle combined with autophagy activation provided a promising therapeutic strategy for bone metastasis treatment. STATEMENT OF SIGNIFICANCE: Due to the limited light penetration, photothermal therapy (PTT) has limited inhibitory effect on tumor cells colonized in the bone. In addition, nonspecific heat diffusion of PTT may accidentally burn normal tissues and damage peripheral blood vessels, which can block the accumulation of drugs in deep tumors. Here, a multifunctional liquid metal based mild-PTT delivery system is designed to inhibit tumor growth and bone resorption by modulating the bone microenvironment and activating autophagy "on demand". It can overcome the treatment bottleneck of traditional PTT and improve the treatment effect of mild-PTT by resisting photothermal resistance and immune suppression. In addition, it also exhibits favorable heat/acid-responsive drug release performance and can specifically target tumor cells at the site of bone metastases.

Recent Advances in Metal-Organic-Framework-Based Nanocarriers for Controllable Drug Delivery and Release

Metal-organic frameworks (MOFs) have a good designability, a well-defined pore, stimulus responsiveness, a high surface area, and a controllable morphology. Up to now, various MOFs have been widely used as nanocarriers and have attracted lots of attention in the field of drug delivery and release because of their good biocompatibility and high-drug-loading capacity. Herein, we provide a comprehensive summary of MOF-based nanocarriers for drug delivery and release over the last five years. Meanwhile, some representative examples are highlighted in detail according to four categories, including the University of Oslo MOFs, Fe-MOFs, cyclodextrin MOFs, and other MOFs. Moreover, the opportunities and challenges of MOF-based smart delivery vehicles are discussed. We hope that this review will be helpful for researchers to understand the recent developments and challenges of MOF-based drug-delivery systems.