A Light-Triggered Mesenchymal Stem Cell Delivery System for Photoacoustic Imaging and Chemo-Photothermal Therapy of Triple Negative Breast Cancer

Cavitation-on-a-Chip Enabled Size-Specific Liposomal Drugs for Selective Pharmacokinetics and Pharmacodynamics

The size of liposomal drugs has been demonstrated to strongly correlate with their pharmacokinetics and pharmacodynamics. While the microfluidic method successfully achieves the production of liposomes with well-controlled sizes across various buffer/lipid flow rate ratio (FRR) settings, any adjustments to the FRR inevitably influence the concentration, encapsulation efficiency (EE), and stability of liposomal drugs. Here we describe a controllable cavitation-on-a-chip (CCC) strategy that facilitates the precise regulation of liposomal drug size at any desired FRR. The CCC-enabled size-specific liposomes exhibited striking differences in uptake and biodistribution behaviors, thereby demonstrating distinct antitumor efficacy in both tumor-bearing animal and melanoma patient-derived organoid (PDO) models. Intriguingly, as the liposome size decreased to approximately 80 nm, the preferential accumulation of liposomal drugs in the liver transitioned to a predominant enrichment in the kidneys. These findings underscore the considerable potential of our CCC approach in influencing the pharmacokinetics and pharmacodynamics of liposomal nanomedicines.

Supramolecular self-assembled gold nanoparticle clusters for synergistic photothermal-chemo tumor therapy

The combination of photothermal therapy and chemotherapy has emerged as a promising strategy to improve cancer therapeutic efficacy. However, developing a versatile nanoplatform that simultaneously possesses commendable photothermal effect and high drug encapsulation efficiency remains a challenging problem yet to be addressed. Herein, we report a facile supramolecular self-assembly strategy to construct gold nanoparticle clusters (AuNCs) for synergistic photothermal-chemo therapy. By utilizing the functional polysaccharide as a targeted ligand, hyaluronic acid-enriched AuNCs were endowed with targeting CD44 receptor overexpressed on the B16 cancer cells. Importantly, these hyaluronic acid modified AuNCs can shelter therapeutic cargo of doxorubicin (DOX) to aggregate larger nanoparticles via a host-guest interaction with the anchored β-cyclodextrin, as a "nanocluster-bomb" (DOX@AuNCs). The in vitro results revealed that these DOX@AuNCs showed light-triggered drug release behavior and synergistic photothermal-chemo therapy. The improved efficacy of synergistic therapy was further demonstrated by treating a xenografted B16 tumor model in vivo. We envision that our multipronged design of DOX@AuNCs provides a potent theranostic platform for precise cancer therapy and could be further enriched by introducing different imaging probes and therapeutic drugs as appropriate suitable guest molecules.

CXCR4-Expressing Mesenchymal Stem Cells Derived Nanovesicles for Rheumatoid Arthritis Treatment

Cell membrane camouflage technology, which a demonstrated value for the bionic replication of natural cell membrane properties, is an active area of ongoing research readily applicable to nanomedicine. How to realize immune evasion, slow down the clearance from the body, and improve targeting are still worth great efforts for this technology. Herein, novel cell membrane-mimicked nanovesicles from genetically engineered mesenchymal stem cells (MSCs) are presented as a potential anti-inflammatory platform for rheumatoid arthritis (RA) management. Utilizing the synthetic biology approach, the biomimetic nanoparticles are constructed by fusing C-X-C motif chemokine receptor4 (CXCR4)-anchored MSC membranes onto drug-loaded polymeric cores (MCPNs), which make them ideal decoys of stromal cell-derived factor-1 (SDF-1)-targeted arthritis. These resulting nanocomplexes function to escape from the immune system and enhance accumulation in the established inflamed joints via the CXCR4/SDF-1 chemotactic signal axis, thereby achieving an affinity to activated macrophages and synovial fibroblasts. It is further demonstrated that the MCPNs can significantly suppress synovial inflammation and relieve pathological conditions with favorable safety properties in collagen-induced arthritis mice. These findings indicate the clinical value of MCPNs as biomimetic nanodrugs for RA therapy and related diseases.

The therapeutic effect of MSCs and their extracellular vesicles on neuroblastoma

Neuroblastoma is a common inflammatory-related cancer during infancy. Standard treatment modalities including surgical interventions, high-dose chemotherapy, radiotherapy, and immunotherapy are not able to increase survival rate and reduce tumor relapse in high-risk patients. Mesenchymal stem cells (MSCs) are known for their tumor-targeting and immunomodulating properties. MSCs could be engineered to express anticancer agents (i.e., growth factors, cytokines, pro-apoptotic agents) or deliver oncolytic viruses in the tumor microenvironment. As many functions of MSCs are mediated through their secretome, researchers have tried to use extracellular vesicles (EVs) from MSCs for targeted therapy of neuroblastoma. Here, we reviewed the studies to figure out whether the use of MSCs could be worthwhile in neuroblastoma therapy or not. Native MSCs have shown a promoting or inhibiting role in cancers including neuroblastoma. Therefore, MSCs are proposed as a vehicle to deliver anticancer agents such as oncolytic viruses to the neuroblastoma tumor microenvironment. Although modified MSCs or their EVs have been shown to suppress the tumorigenesis of neuroblastoma, further pre-clinical and clinical studies are required to come to a conclusion.

Biodistribution and Targeted Antitumor Effects of Trastuzumab-Modified Gold Nanorods in Mice with Gastric Cancer

BACKGROUND AND OBJECTIVES

Targeted drug is often engulfed and cleared by the reticuloendothelial system in vivo, resulting in reduced treatment efficacy. This study aimed to explore the biodistribution and HER-2-targeted antitumor effects of trastuzumab-modified gold nanorods (Tra-AuNRs) in a gastric cancer animal model.

METHODS

Gold nanorods were synthesized using a seed-mediated growth method, and then subjected to trastuzumab-targeted modification. Elemental analysis, Fourier transform infrared spectroscopy, and Xray photoelectron spectroscopy were performed; UV-visible absorption peak, photothermal effects, morphology, and size distribution of Tra-AuNRs were characterized. The targeted killing effect of Tra- AuNRs on gastric cancer cells was assessed in vitro. Tra-AuNRs were injected intravenously and intratumorally into gastric cancer-bearing nude mice in vivo and their distribution was detected. Tumor growth inhibition rate and tumor apoptosis-related protein expression were compared between groups.

RESULTS

Tra-AuNRs presented a relatively uniform morphology with an average particle size of 59.9 nm and a longitudinal plasmon resonance absorption peak of 790 nm. The targeted killing rate of gastric cancer cells in vitro by Tra-AuNRs was 87.9%. After intravenous injection, Tra-AuNRs were mainly distributed in the liver, tumor, spleen, and lungs. Comparatively, Tra-AuNRs were mainly distributed in the tumor when intratumorally injected, with a tumor concentration of 6.42 μg/g after 24 h. The tumor growth inhibition rate reached 78.3% in the intratumoral injection group, with significantly higher BAX, BAD, and CASPASE-3 expression than that in the intravenous injection group.

CONCLUSION

The findings suggest that Tra-AuNRs can be used for HER-2-positive gastric cancer treatment. Intratumoral injection of Tra-AuNRs significantly increased the local tumor drug concentration and improved the molecular targeted antitumor growth effect in gastric cancer-bearing nude mice.

Tumor-tropic Trojan horses: Using mesenchymal stem cells as cellular nanotheranostics

Various classes of nanotheranostics have been developed for enhanced tumor imaging and therapy. However, key limitations for a successful use of nanotheranostics include their targeting specificity with limited off-site tissue accumulation as well as their distribution and prolonged retention throughout the entire tumor. Due to their inherent tumor-tropic properties, the use of mesenchymal stem cells (MSCs) as a "Trojan horse" has recently been proposed to deliver nanotheranostics more effectively. This review discusses the current status of "cellular nanotheranostics" for combined (multimodal) imaging and therapy in preclinical cancer models. Emphasis is placed on the limited knowledge of the signaling pathways and molecular mechanisms of MSC tumor-tropism, and how such information may be exploited to engineer MSCs in order to further improve tumor homing and nanotheranostic delivery using image-guided procedures.

Nanotheranostics: Molecular Diagnostics and Nanotherapeutic Evaluation by Photoacoustic/Ultrasound Imaging in Small Animals

Nanotheranostics is a rapidly developing field that integrates nanotechnology, diagnostics, and therapy to provide novel methods for imaging and treating wide categories of diseases. Targeted nanotheranostics offers a platform for the precise delivery of theranostic agents, and their therapeutic outcomes are monitored in real-time. Presently, in vivo magnetic resonance imaging, fluorescence imaging, ultrasound imaging, and photoacoustic imaging (PAI), etc. are noninvasive imaging techniques that are preclinically available for the imaging and tracking of therapeutic outcomes in small animals. Additionally, preclinical imaging is essential for drug development, phenotyping, and understanding disease stage progression and its associated mechanisms. Small animal ultrasound imaging is a rapidly developing imaging technique for theranostics applications due to its merits of being nonionizing, real-time, portable, and able to penetrate deep tissues. Recently, different types of ultrasound contrast agents have been explored, such as microbubbles, echogenic exosomes, gas-vesicles, and nanoparticles-based contrast agents. Moreover, an optical image obtained through photoacoustic imaging is a noninvasive imaging technique that creates ultrasonic waves when pulsed laser light is used to expose an object and creates a picture of the tissue's distribution of light energy absorption on the object. Contrast agents for photoacoustic imaging may be endogenous (hemoglobin, melanin, and DNA/RNA) or exogenous (dyes and nanomaterials-based contrast agents). The integration of nanotheranostics with photoacoustic and ultrasound imaging allows simultaneous imaging and treatment of diseases in small animals, which provides essential information about the drug response and the disease progression. In this review, we have covered various endogenous and exogenous contrast agents for ultrasound and photoacoustic imaging. Additionally, we have discussed various drug delivery systems integrated with contrast agents for theranostic application. Further, we have briefly discussed the current challenges associated with ultrasound and photoacoustic imaging.

Current progress in engineered and nano-engineered mesenchymal stem cells for cancer: From mechanisms to therapy

Mesenchymal stem cells (MSCs), as self-renewing multipotent stromal cells, have been considered promising agents for cancer treatment. A large number of studies have demonstrated the valuable properties of MSC-based treatment, such as low immunogenicity and intrinsic tumor-trophic migratory properties. To enhance the potency of MSCs for therapeutic purposes, equipping MSCs with targeted delivery functions using genetic engineering is highly beneficial. Genetically engineered MSCs can express tumor suppressor agents such as pro-apoptotic, anti-proliferative, anti-angiogenic factors and act as ideal delivery vehicles. MSCs can also be loaded with nanoparticle drugs for increased efficacy and externally moderated targeting. Moreover, exosomes secreted by MSCs have important physiological properties, so they can contribute to intercellular communication and transfer cargo into targeted tumor cells. The precise role of genetically modified MSCs in tumor environments is still up for debate, but the beginning of clinical trials has been confirmed by promising results from preclinical investigations of MSC-based gene therapy for a wide range of malignancies. This review highlights the advanced techniques of engineering/nano-engineering and MSC-derived exosomes in tumor-targeted therapy.

Xenogeneic equine stem cells activate anti-tumor adaptive immunity in a 4T1-based intraductal mouse model for triple-negative breast cancer: proof-of-principle

Triple-negative breast cancer (TNBC) remains difficult to treat, especially due to ineffective immune responses. Current treatments mainly aim at a cytotoxic effect, whereas (stem) cell therapies are being investigated for their immune stimulatory capacities to initiate the anti-tumor immunity. Here, a thoroughly characterized, homogenous and non-tumorigenic mixture of equine mesenchymal stem cells (eMSCs) harvested from horse peripheral blood as innovative xenogeneic immunomodulators were tested in a 4T1-based intraductal mouse model for TNBC. The eMSCs significantly reduced 4T1 progression upon systemic injection, with induction of inflammatory mediators and T-cell influx in primary tumors, already after a single dose. These xenogeneic anti-cancer effects were not restricted to MSCs as systemic treatment with alternative equine epithelial stem cells (eEpSCs) mimicked the reported disease reduction. Mechanistically, effective eMSC treatment did not rely on the spleen as systemic entrapment site, whereas CD4+ and CD8α+ T-cell infiltration and activation were critical. These results show that eMSCs and potentially also other equine stem cell types can be a valuable TNBC treatment strategy for further (pre)clinical evaluation.

Advances in nanomedicines for lymphatic imaging and therapy

Lymph nodes play a pivotal role in tumor progression as key components of the lymphatic system. However, the unique physiological structure of lymph nodes has traditionally constrained the drug delivery efficiency. Excitingly, nanomedicines have shown tremendous advantages in lymph node-specific delivery, enabling distinct recognition and diagnosis of lymph nodes, and hence laying the foundation for efficient tumor therapies. In this review, we comprehensively discuss the key factors affecting the specific enrichment of nanomedicines in lymph nodes, and systematically summarize nanomedicines for precise lymph node drug delivery and therapeutic application, including the lymphatic diagnosis and treatment nanodrugs and lymph node specific imaging and identification system. Notably, we delve into the critical challenges and considerations currently facing lymphatic nanomedicines, and futher propose effective strategies to address these issues. This review encapsulates recent findings, clinical applications, and future prospects for designing effective nanocarriers for lymphatic system targeting, with potential implications for improving cancer treatment strategies.

Inorganic nanoparticle-integrated mesenchymal stem cells: A potential biological agent for multifaceted applications

Mesenchymal stem cell (MSC)-based therapies are flourishing. MSCs could be used as potential therapeutic agents for regenerative medicine due to their own repair function. Meanwhile, the natural predisposition toward inflammation or injury sites makes them promising carriers for targeted drug delivery. Inorganic nanoparticles (INPs) are greatly favored for their unique properties and potential applications in biomedical fields. Current research has integrated INPs with MSCs to enhance their regenerative or antitumor functions. This model also allows the in vivo fate tracking of MSCs in multiple imaging modalities, as many INPs are also excellent contrast agents. Thus, INP-integrated MSCs would be a multifunctional biologic agent with great potential. In this review, the current roles performed by the integration of INPs with MSCs, including (i) enhancing their repair and regeneration capacity via the improvement of migration, survival, paracrine, or differentiation properties, (ii) empowering tumor-killing ability through agent loaded or hyperthermia, and (iii) conferring traceability are summarized. An introduction of INP-integrated MSCs for simultaneous treatment and tracking is also included. The promising applications of INP-integrated MSCs in future treatments are emphasized and the challenges to their clinical translation are discussed.

Multifunctional nano-system for multi-mode targeted imaging and enhanced photothermal therapy of metastatic prostate cancer

Prostate cancer (PCa) routinely employs magnetic resonance (MR) imaging, while metastatic PCa needs more complicated detection methods for precise localization. The inconvenience of using different methods to detect PCa and its metastases in patients and the limitations of single-mode imaging have brought great challenges to clinicians. Meanwhile, clinical treatments for metastatic PCa are still limited. Herein, we report a targeted theranostic platform of Au/Mn nanodots-luteinising hormone releasing hormone (AMNDs-LHRH) nano-system for multi-mode imaging guided photothermal therapy of PCa. The nano-system not only can simultaneously target Gonadotropin-Releasing Hormone Receptor (GnRH-R) positive PCa and its metastases for accurate preoperative CT/MR diagnosis, but also possesses fluorescence (FL) visualization navigated surgery, demonstrating its potential application in clinical cancer detection and surgery guidance. Meanwhile, the AMNDs-LHRH with promising targeting and photothermal conversion ability significantly improve the photothermal therapy effect of metastatic PCa. The AMNDs-LHRH nano-system guarantees the diagnostic accuracy and enhanced therapeutic effect, which provides a promising platform for clinical diagnosis and treatment of metastatic PCa. STATEMENT OF SIGNIFICANCE: Accurate clinical diagnosis and treatment of prostate cancer and its metastases is challenging. A targeted theranostic platform of AMNDs-LHRH nano-system for multi-mode imaging (FL/CT/MR) guided photothermal therapy of metastatic prostate cancer has been reported. The nano-system not only can simultaneously target prostate cancer and its metastases for accurate preoperative CT/MR diagnosis, but also possesses fluorescence visualization navigated surgery, demonstrating its potential application in clinical cancer detection and surgery guidance. The nano-system with great targeting and photothermal conversion ability significantly improve the photothermal therapy effect of metastatic prostate cancer. Overall, the AMNDs-LHRH nano-system integrates tumor targeting, multi-mode imaging and enhanced therapeutic effect, which can provide an effective strategy for the clinical diagnosis and treatment of metastatic PCa.

Cell membrane-coated nanomaterials for cancer therapy

With the development of nanotechnology, nanoparticles have emerged as a delivery carrier for tumor drug therapy, which can improve the therapeutic effect by increasing the stability and solubility and prolonging the half-life of drugs. However, nanoparticles are foreign substances for humans, are easily cleared by the immune system, are less targeted to tumors, and may even be toxic to the body. As a natural biological material, cell membranes have unique biological properties, such as good biocompatibility, strong targeting ability, the ability to evade immune surveillance, and high drug-carrying capacity. In this article, we review cell membrane-coated nanoparticles (CMNPs) and their applications to tumor therapy. First, we briefly describe CMNP characteristics and applications. Second, we present the characteristics and advantages of different cell membranes as well as nanoparticles, provide a brief description of the process of CMNPs, discuss the current status of their application to tumor therapy, summarize their shortcomings for use in cancer therapy, and propose future research directions. This review summarizes the research progress on CMNPs in cancer therapy in recent years and assesses remaining problems, providing scholars with new ideas for future research on CMNPs in tumor therapy.

Photothermal Nanomaterials: A Powerful Light-to-Heat Converter

All forms of energy follow the law of conservation of energy, by which they can be neither created nor destroyed. Light-to-heat conversion as a traditional yet constantly evolving means of converting light into thermal energy has been of enduring appeal to researchers and the public. With the continuous development of advanced nanotechnologies, a variety of photothermal nanomaterials have been endowed with excellent light harvesting and photothermal conversion capabilities for exploring fascinating and prospective applications. Herein we review the latest progresses on photothermal nanomaterials, with a focus on their underlying mechanisms as powerful light-to-heat converters. We present an extensive catalogue of nanostructured photothermal materials, including metallic/semiconductor structures, carbon materials, organic polymers, and two-dimensional materials. The proper material selection and rational structural design for improving the photothermal performance are then discussed. We also provide a representative overview of the latest techniques for probing photothermally generated heat at the nanoscale. We finally review the recent significant developments of photothermal applications and give a brief outlook on the current challenges and future directions of photothermal nanomaterials.

From Interaction to Intervention: How Mesenchymal Stem Cells Affect and Target Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) lacks estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expressions, making targeted therapies ineffective. Mesenchymal stem cells (MSCs) have emerged as a promising approach for TNBC treatment by modulating the tumor microenvironment (TME) and interacting with cancer cells. This review aims to comprehensively overview the role of MSCs in TNBC treatment, including their mechanisms of action and application strategies. We analyze the interactions between MSC and TNBC cells, including the impact of MSCs on TNBC cell proliferation, migration, invasion, metastasis, angiogenesis, and drug resistance, along with the signaling pathways and molecular mechanisms involved. We also explore the impact of MSCs on other components of the TME, such as immune and stromal cells, and the underlying mechanisms. The review discusses the application strategies of MSCs in TNBC treatment, including their use as cell or drug carriers and the advantages and limitations of different types and sources of MSCs in terms of safety and efficacy. Finally, we discuss the challenges and prospects of MSCs in TNBC treatment and propose potential solutions or improvement methods. Overall, this review provides valuable insights into the potential of MSCs as a novel therapeutic approach for TNBC treatment.

Recent advancements to engineer mesenchymal stem cells and their extracellular vesicles for targeting and destroying tumors

Mesenchymal stem cells (MSCs) have the ability to migrate into tumor sites and release growth factors to modulate the tumor microenvironment. MSC therapy have shown a dual role in cancers, promoting or inhibiting. However, MSCs could be used as a carrier of anticancer agents for targeted tumor therapy. Recent technical improvements also allow engineering MSCs to improve tumor-targeting properties, protect anticancer agents, and decrease the cytotoxicity of drugs. While some of MSC functions are mediated through their secretome, MSCs-derived extracellular vesicles (EVs) are also proposed as a possible viechle for cancer therapy. EVs allow efficient loading of anticancer agents and have an intrinsic ability to target tumor cells, making them suitable for targeted therapy of tumors. In addition, the specificity and selectivity of EVs to the tumor sites could be enhanced by surface modification. In this review, we addressed the current approaches used for engineering MSCs and EVs to effectively target tumor sites and deliver anticancer agents.

Biomedical Photoacoustic Imaging for Molecular Detection and Disease Diagnosis: "Always-On" and "Turn-On" Probes

Photoacoustic (PA) imaging is a nonionizing, noninvasive imaging technique that combines optical and ultrasonic imaging modalities to provide images with excellent contrast, spatial resolution, and penetration depth. Exogenous PA contrast agents are created to increase the sensitivity and specificity of PA imaging and to offer diagnostic information for illnesses. The existing PA contrast agents are categorized into two groups in this review: "always-on" and "turn-on," based on their ability to be triggered by target molecules. The present state of these probes, their merits and limitations, and their future development, is explored.

Membrane-wrapped nanoparticles for photothermal cancer therapy

Cancer is a global health problem that needs effective treatment strategies. Conventional treatments for solid-tumor cancers are unsatisfactory because they cause unintended harm to healthy tissues and are susceptible to cancer cell resistance. Nanoparticle-mediated photothermal therapy is a minimally invasive treatment for solid-tumor cancers that has immense promise as a standalone therapy or adjuvant to other treatments like chemotherapy, immunotherapy, or radiotherapy. To maximize the success of photothermal therapy, light-responsive nanoparticles can be camouflaged with cell membranes to endow them with unique biointerfacing capabilities that reduce opsonization, prolong systemic circulation, and improve tumor delivery through enhanced passive accumulation or homotypic targeting. This ensures a sufficient dose of photoresponsive nanoparticles arrives at tumor sites to enable their complete thermal ablation. This review summarizes the state-of-the-art in cell membrane camouflaged nanoparticles for photothermal cancer therapy and provides insights to the path forward for clinical translation.

Membrane-wrapped nanoparticles for nucleic acid delivery

There is an unmet need for carriers that can deliver nucleic acids (NAs) to cancer cells and tumors to perpetuate gene regulation and manage disease progression. Membrane-wrapped nanoparticles (NPs) can be loaded with exogenously designed nucleic acid cargoes, such as plasmid deoxyribonucleic acid (pDNA), messenger ribonucleic acid (mRNA), small interfering RNA (siRNA), microRNA (miRNA), and immunostimulatory CpG oligodeoxynucleotides (CpG ODNs), to mitigate challenges presented by NAs' undesirable negative charge, hydrophilicity, and relatively large size. By conjugating or encapsulating NAs within membrane-wrapped NPs, various physiological barriers can be overcome so that NAs experience increased blood circulation half-lives and enhanced accumulation in intended sites. This review discusses the status of membrane-wrapped NPs as NA delivery vehicles and their advancement in gene regulation for cancer management in vitro and in vivo. With continued development, membrane-wrapped NPs have great potential as future clinical tools to treat cancer and other diseases with a known genetic basis.

Trends in iron oxide nanoparticles: a nano-platform for theranostic application in breast cancer

Breast cancer (BC) is the deadliest malignant disorder globally, with a significant mortality rate. The development of tolerance throughout cancer treatment and non-specific targeting limits the drug's response. Currently, nano therapy provides an interdisciplinary area for imaging, diagnosis, and targeted drug delivery for BC. Several overexpressed biomarkers, proteins, and receptors are identified in BC, which can be potentially targeted by using nanomaterial for drug/gene/immune/photo-responsive therapy and bio-imaging. In recent applications, magnetic iron oxide nanoparticles (IONs) have shown tremendous attention to the researcher because they combine selective drug delivery and imaging functionalities. IONs can be efficaciously functionalised for potential application in BC therapy and diagnosis. In this review, we explored the current application of IONs in chemotherapeutics delivery, gene delivery, immunotherapy, photo-responsive therapy, and bio-imaging for BC based on their molecular mechanism. In addition, we also highlighted the effect of IONs' size, shape, dimension, and functionalization on BC targeting and imaging. To better comprehend the functionalization potential of IONs, this paper provides an outline of BC cellular development. IONs for BC theranostic are also reviewed based on their clinical significance and future aspects.

Mesenchymal stem cells: A living carrier for active tumor-targeted delivery

The strategy of using mesenchymal stem cells (MSCs) as a living carrier for active delivery of therapeutic agents targeting tumor sites has been attempted in a wide range of studies to validate the feasibility and efficacy for tumor treatment. This approach reveals powerful tumor targeting and tumor penetration. In addition, MSCs have been confirmed to actively participate in immunomodulation of the tumor microenvironment. Thus, MSCs are not inert delivery vehicles but have a strong impact on the fate of tumor cells. In this review, these active properties of MSCs are addressed to highlight the advantages and challenges of using MSCs for tumor-targeted delivery. In addition, some of the latest examples of using MSCs to carry a variety of anti-tumor agents for tumor-targeted therapy are summarized. Recent technologies to improve the performance and safety of this delivery strategy will be introduced. The advances, applications, and challenges summarized in this review will provide a general understanding of this promising strategy for actively delivering drugs to tumor tissues.

Breast Cancer Therapy: The Potential Role of Mesenchymal Stem Cells in Translational Biomedical Research

The potential role of mesenchymal stem cells (MSCs) in the treatment of metastatic cancers, including breast cancer, has been investigated for many years leading to encouraging results. The role of fat grafting and the related adipose-derived mesenchymal stem cells (AD-MSCs) has been detailed and described for breast reconstruction purposes confirming the safety of AD-MSCs. MSCs have great potential for delivering anticancer agents, suicide genes, and oncolytic viruses to tumors. Currently, many studies have focused on the products of MSCs, including extracellular vesicles (EVs), as a cell-free therapy. This work aimed to review and discuss the current knowledge on MSCs and their EVs in breast cancer therapy.

Engineered Mesenchymal Stem Cells as a Biotherapy Platform for Targeted Photodynamic Immunotherapy of Breast Cancer

Interleukin-12 (IL12) is a pleiotropic cytokine with promising prospects for cancer immunotherapy. Though IL12 gene-based therapy can overcome the fatal hurdle of severe systemic toxicity, targeted delivery and tumor-located expression of IL12 gene remain the challenging issues yet to be solved. Photo-immunotherapy emerging as a novel and precise therapeutic strategy, which elaborately combines immune-activating agents with light-triggered photosensitizers for potentiated anticancer efficacy. Herein, an engineered stem cell-based biotherapy platform (MB/IL12-MSCs) incorporating immune gene plasmid IL12 (pIL12) and photosensitizer methylene blue (MB) is developed to realize tumor-homing delivery of therapeutic agents and photo-immunotherapy efficacy enhancement. The biotherapy platform retained tumor-tropic migration and penetration functions, which improved the intratumoral distribution of therapeutic agents, thereby promoting photodynamic effects and reinforcing immune responses. Importantly, MB/IL12-MSCs restricted the expression and distribution of IL12 at tumor site, which minimized potential toxicity while eliciting sufficient anticancer immunity. In noteworthy, activation of immunity induced by MB/IL12-MSCs established long-term systemic immunologic memory to prevent tumor relapse. The MB/IL12-MSCs outperform their monotherapy counterparts in breast tumor models, and the growth of tumor significantly arrested as well as re-challenging abscopal tumor growth slowdown. Collectively, this work reveals that MSCs-based strategy may advance more efficient, durable, and safer cancer photo-immunotherapy.

Enzyme Catalysis Biomotor Engineering of Neutrophils for Nanodrug Delivery and Cell-Based Thrombolytic Therapy

Utilizing neutrophils (NEs) to target and deliver nanodrugs to inflammation sites has received considerable attention. NEs are involved in the formation and development of thrombosis by transforming into neutrophil extracellular traps (NETs); this indicates that NEs may be a natural thrombolytic drug delivery carrier. However, NEs lack an effective power system to overcome blood flow resistance and enhance targeting efficiency. Herein, we report the application of a urease catalysis micromotor powered NEs nanodrug delivery system to promote thrombolysis and suppress rethrombosis. The urease micromotor powered Janus NEs (UM-NEs) were prepared by immobilizing the enzyme asymmetrically onto the surface of natural NEs and then loading urokinase (UK) coupled silver (Ag) nanoparticles (Ag-UK) to obtain the UM-NEs (Ag-UK) system. Urease catalytic endogenous urea is used to generate thrust by producing ammonia and carbon dioxide, which propels NEs actively targeting the thrombus. The UM-NEs (Ag-UK) can be activated by enriched inflammatory cytokines to release NETs at the thrombosis site, resulting in a concomitant release of Ag-UK. Ag-UK induces thrombolysis to restore vascular recanalization. This urease micromotor-driven NEs drug delivery system can significantly reduce the hemorrhagic side effects, promote thrombolysis, and inhibit rethrombosis with high bioavailability and biosafety, which can be used for the treatment of thrombotic diseases.

Multimodal Imaging-Guided Spatiotemporal Tracking of Photosensitive Stem Cells for Breast Cancer Treatment

Stem cell therapy has shown great potential in treating a wide range of diseases including cancer. The real-time tracking of stem cells with high spatiotemporal resolution and stable imaging signals remains the bottleneck to evaluate and monitor therapeutic outcomes once transplanted into patients. Here, we developed a photosensitive mesenchymal stem cell (MSC) loaded with mesoporous silica-coated gold nanostars (MGNSs) integrated with indocyanine green for spatiotemporal tracking and imaging-guided photothermal therapy (PTT) in treating breast cancers. The MGNS served as a stable imaging probe with multifunctional properties for photoacoustic imaging (PAI), fluorescence imaging, and PT imaging. Owing to the excellent PT stability of MGNSs, long-term three-dimensional (3D) PAI was achieved to monitor stem cells in real time at the tumor site, while the tumor structure was imaged using 3D B-mode ultrasound imaging. PAI revealed that the photosensitive stem cells reached the widest distribution area at the tumor site post 24 h of intratumoral injection, which was further confirmed via two-dimensional (2D) PT and fluorescence imaging. With this optimal cell distribution window, in vivo studies showed that the photosensitive stem cells via both intratumoral and intravenous injections successfully inhibited breast cancer cell growth and decreased the tumor recurrence rate post PTT. Our results support that this photo-integrated platform with stable optical properties is promising to achieve real-time tracking and measure the cell distribution quantitatively with high spatiotemporal resolution for stem cell therapy.

Computational analysis of drug free silver triangular nanoprism theranostic probe plasmonic behavior for in-situ tumor imaging and photothermal therapy

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Designing drug-free polyvinyl alcohol coated stable silver triangular nano-prisms (PVA-SNT).

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Computational simulation of optical and photothermal properties with high in vivo experimental similarity.

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Stable PVA-SNT enables photoacoustic imaging-guided photothermal therapy of breast cancer.

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PVA-SNT exhibits enhanced photostability and high photothermal conversion efficiency.

Introduction

The advanced features of plasmonic nanomaterials enable initial high accuracy detection with different therapeutic intervention. Computational simulations could estimate the plasmonic heat generation with a high accuracy and could be reliably compared to experimental results. This proposed combined theoretical-experimental strategy may help researchers to better understand other nanoparticles in terms of plasmonic efficiency and usability for future nano-theranostic research.

Objectives

To develop innovative computationally-driven approach to quantify any plasmonic nanoparticles photothermal efficiency and effects before their use as therapeutic agents.

Methods

This report introduces drug free plasmonic silver triangular nanoprisms coated with polyvinyl alcohol biopolymer (PVA-SNT), for in vivo photoacoustic imaging (PAI) guided photothermal treatment (PTT) of triple-negative breast cancer mouse models. The synthesized PVA-SNT nanoparticles were characterized and a computational electrodynamic analysis was performed to evaluate and predict the optical and plasmonic photothermal properties. The in vitro biocompatibility and in vivo tumor abalation study was performed with MDA-MB-231 human breast cancer cell line and in nude mice model.

Results

The drug free 140 μg∙mL⁻¹ PVA-SNT nanoparticles with 1.0 W∙cm⁻² laser irradiation for 7 min proved to be an effective and optimized theranostic approach in terms of PAI guided triple negative breast cancer treatment. The PVA-SNT nanoparticles exhibits excellent biosafety, photostability, and strong efficiency as PAI contrast agent to visualize tumors. Histological analysis and fluorescence-assisted cell shorter assay results post-treatment apoptotic cells, more importantly, it shows substantial damage to in vivo tumor tissues, killing almost all affected cells, with no recurrence.

Conclusion

This is a first complete study on computational simulations to estimate the plasmonic heat generation followed by drug free plasmonic PAI guided PTT for cancer treatment. This computationally-driven theranostic approach demonstrates an innovative thought regarding the nanoparticles shape, size, concentration, and composition which could be useful for the prediction of photothermal heat generation in precise nanomedicine applications.

Graphene-based nanomaterials for cancer therapy and anti-infections

Graphene-based nanomaterials (GBNMs) has been thoroughly investigated and extensively used in many biomedical fields, especially cancer therapy and bacteria-induced infectious diseases treatment, which have attracted more and more attentions due to the improved therapeutic efficacy and reduced reverse effect. GBNMs, as classic two-dimensional (2D) nanomaterials, have unique structure and excellent physicochemical properties, exhibiting tremendous potential in cancer therapy and bacteria-induced infectious diseases treatment. In this review, we first introduced the recent advances in development of GBNMs and GBNMs-based treatment strategies for cancer, including photothermal therapy (PTT), photodynamic therapy (PDT) and multiple combination therapies. Then, we surveyed the research progress of applications of GBNMs in anti-infection such as antimicrobial resistance, wound healing and removal of biofilm. The mechanism of GBNMs was also expounded. Finally, we concluded and discussed the advantages, challenges/limitations and perspective about the development of GBNMs and GBNMs-based therapies. Collectively, we think that GBNMs could be potential in clinic to promote the improvement of cancer therapy and infections treatment.

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Development of GBNMs with unique structure and excellent properties.

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GBNMs-based therapies for anticancer with improved therapeutic efficacy.

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GBNMs with antimicrobial activity are widely used in anti-infections.

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The challenges and perspective of GBNMs for clinical use were thoroughly discussed.

Iron Oxide Nanoparticles in Mesenchymal Stem Cell Detection and Therapy

Mesenchymal stem cells (MSCs) exhibit regenerative and reparative properties. However, most MSC-related studies remain to be translated for regular clinical usage, partly due to challenges in pre-transplantation cell labelling and post-transplantation cell tracking. Amidst this, there are growing concerns over the toxicity of commonly used gadolinium-based contrast agents that mediate in-vivo cell detection via MRI. This urges to search for equally effective but less toxic alternatives that would facilitate and enhance MSC detection post-administration and provide therapeutic benefits in-vivo. MSCs labelled with iron oxide nanoparticles (IONPs) have shown promising results in-vitro and in-vivo. Thus, it would be useful to revisit these studies before inventing new labelling approaches. Aiming to inform regenerative medicine and augment clinical applications of IONP-labelled MSCs, this review collates and critically evaluates the utility of IONPs in enhancing MSC detection and therapeutics. It explains the rationale, principle, and advantages of labelling MSCs with IONPs, and describes IONP-induced intracellular alterations and consequent cellular manifestations. By exemplifying clinical pathologies, it examines contextual in-vitro, animal, and clinical studies that used IONP-labelled bone marrow-, umbilical cord-, adipose tissue- and dental pulp-derived MSCs. It compiles and discusses studies involving MSC-labelling of IONPs in combinations with carbohydrates (Venofer, ferumoxytol, dextran, glucosamine), non-carbohydrate polymers [poly(L-lysine), poly(lactide-co-glycolide), poly(L-lactide), polydopamine], elements (ruthenium, selenium, gold, zinc), compounds/stains (silica, polyethylene glycol, fluorophore, rhodamine B, DAPI, Prussian blue), DNA, Fibroblast growth Factor-2 and the drug doxorubicin. Furthermore, IONP-labelling of MSC exosomes is reviewed. Also, limitations of IONP-labelling are addressed and methods of tackling those challenges are suggested.

Advanced applications of cerium oxide based nanozymes in cancer

Cerium oxide nanozymes have emerged as a new type of bio-antioxidants in recent years. CeO2 nanozymes possess enzyme mimetic activities with outstanding free radical scavenging activity, facile synthesis conditions, and excellent biocompatibility. Based on these extraordinary properties, use of CeO2 nanozymes has been demonstrated to be a highly versatile therapeutic method for many diseases, such as for inflammation, rheumatoid arthritis, hepatic ischemia-reperfusion injury and Alzheimer's disease. In addition to that, CeO2 nanozymes have been widely used in the diagnosis and treatment of cancer. Many examples can be found in the literature, such as magnetic resonance detection, tumour marker detection, chemotherapy, radiotherapy, photodynamic therapy (PDT), and photothermal therapy (PTT). This review systematically summarises the latest applications of CeO2-based nanozymes in cancer research and treatment. We believe that this paper will help develop value-added CeO2 nanozymes, offering great potential in the biotechnology industry and with great significance for the diagnosis and treatment of a wide range of malignancies.

Therapeutic Potential of Thymoquinone in Triple-Negative Breast Cancer Prevention and Progression through the Modulation of the Tumor Microenvironment

To date, the tumor microenvironment (TME) has gained considerable attention in various areas of cancer research due to its role in driving a loss of immune surveillance and enabling rapid advanced tumor development and progression. The TME plays an integral role in driving advanced aggressive breast cancers, including triple-negative breast cancer (TNBC), a pivotal mediator for tumor cells to communicate with the surrounding cells via lymphatic and circulatory systems. Furthermore, the TME plays a significant role in all steps and stages of carcinogenesis by promoting and stimulating uncontrolled cell proliferation and protecting tumor cells from the immune system. Various cellular components of the TME work together to drive cancer processes, some of which include tumor-associated adipocytes, fibroblasts, macrophages, and neutrophils which sustain perpetual amplification and release of pro-inflammatory molecules such as cytokines. Thymoquinone (TQ), a natural chemical component from black cumin seed, is widely used traditionally and now in clinical trials for the treatment/prevention of multiple types of cancer, showing a potential to mitigate components of TME at various stages by various pathways. In this review, we focus on the role of TME in TNBC cancer progression and the effect of TQ on the TME, emphasizing their anticipated role in the prevention and treatment of TNBC. It was concluded from this review that the multiple components of the TME serve as a critical part of TNBC tumor promotion and stimulation of uncontrolled cell proliferation. Meanwhile, TQ could be a crucial compound in the prevention and progression of TNBC therapy through the modulation of the TME.

Combined Photothermotherapy and Chemotherapy of Oral Squamous Cell Carcinoma Guided by Multifunctional Nanomaterials Enhanced Photoacoustic Tomography

Background

Squamous cell carcinoma of the head and neck is the sixth most common cancer worldwide, with 40% occurring in the oral cavity. Although the level of early diagnosis and treatment of OSCC has improved significantly, the five-year survival rate of advanced patients remains unsatisfactory. However, the main challenges before us are how to get an early and accurate diagnosis and how to formulate effective treatment. Nanoparticle-based chemo-photothermal therapy has proven to be a promising non-invasive approach to treating oral squamous cell carcinoma treatment.

Methods

In this study, we tried to design and synthesize multifunctional hyaluronic acid (HA) modified gold nanorods/mesoporous silica-based nanoparticles loaded with doxorubicin hydrochloride (DOX) for photoacoustic imaging (PAI) guided cooperative chemo-photothermal therapy.

Results

The resultant nanocomposite shows favorable biocompatibility, relatively low cytotoxicity, ideal drug loading capability and strong PAI signals. In addition, they showed an excellent photothermal conversion efficiency of 49.02% for photothermal therapy (PTT). Moreover, in vivo and in vitro experiments have shown that synergistic chemo-photothermal therapy has better therapeutic effects than chemotherapy alone or PTT (P < 0.05). After being injected into the CAL-27 tumor-bearing mice, the DOX-AuNRs@mSiO₂-HA nanoparticles could accumulate rapidly at the tumor sites and achieve complete ablation of tumors when combined with near-infrared laser irradiation, without obvious side effects on normal tissues.

Conclusion

Our research provides a solid demonstration of the potential of DOX-AuNRs@mSiO₂-HA as a multifunctional platform in PAI-guided photothermal chemotherapy for oral squamous cell carcinoma.

Acoustic Standing Wave Aided Multiparametric Photoacoustic Imaging Flow Cytometry

Photoacoustic imaging reveals great potential for the study of individual cells due to the rich imaging contrast for both label-free and labeled cells. However, previously reported photoacoustic imaging flow cytometry configuration suffers from inadequate imaging quality and challenge to distinguish multiple cells. In order to solve such issues, we propose a novel acoustic standing wave aided multiparametric photoacoustic imaging flow cytometry (MPAFC) system. The acoustic standing wave is introduced to improve the imaging quality and speed. Multispectral illumination along with cell geometry, photoacoustic amplitude, and acoustic frequency spectrum enables the proposed system to precisely identify multiple types of cells with one scanning. On the basis of the identification, elimination of melanoma cells, and targeted labeled glioma cells have been performed with an elimination efficiency of >95%. Additionally, the MPAFC system is able to image and capture melanoma cells at a lowest concentration of 100 cells mL^-1 in pure blood. Current results suggest that the proposed MPAFC may provide a precise and efficient tool for cell detection, manipulation, and elimination in both fundamental and clinical studies.

Molecular Imaging-Guided Sonodynamic Therapy

Low-intensity ultrasound-triggered sonodynamic therapy (SDT) is a promising noninvasive therapeutic modality due to its strong tissue penetration ability. In recent years, with the development of nanotechnology, nanoparticle-based sonosensitizer-mediated SDT has been widely investigated. With the increasing demand for precise and personalized treatment, abundant novel sonosensitizers with imaging capabilities have been developed for determining the optimal therapeutic window, thus significantly enhancing treatment efficacy. In this review, we focus on the molecular imaging-guided SDT. The prevalent mechanisms of SDT are discussed, including ultrasonic cavitation, sonoluminescence, reactive oxygen species, and mechanical damage. In addition, we introduce the major molecular imaging techniques and the design principles based on nanoparticles to achieve efficient imaging. Furthermore, the imaging-guided SDT for the treatment of cancer, bacterial infections, and vascular diseases is summarized. The ultimate goal is to design more effective imaging-guided SDT modalities and provide novel ideas for clinical translation of SDT.

Contrast agents for photoacoustic imaging: a review of stem cell tracking

With the advent of stem cell therapy for spinal cord injuries, stroke, burns, macular degeneration, heart diseases, diabetes, rheumatoid arthritis and osteoarthritis; the need to track the survival, migration pathways, spatial destination and differentiation of transplanted stem cells in a clinical setting has gained increased relevance. Indeed, getting regulatory approval to use these therapies in the clinic depends on biodistribution studies. Although optoacoustic imaging (OAI) or photoacoustic imaging can detect functional information of cell activities in real-time, the selection and application of suitable contrast agents is essential to achieve optimal sensitivity and contrast for sensing at clinically relevant depths and can even provide information about molecular activity. This review explores OAI methodologies in conjunction with the specific application of exogenous contrast agents in comparison to other imaging modalities and describes the properties of exogenous contrast agents for quantitative and qualitative monitoring of stem cells. Specific characteristics such as biocompatibility, the absorption coefficient, and surface functionalization are compared and how the labelling efficiency translates to both short and long-term visualization of mesenchymal stem cells is explored. An overview of novel properties of recently developed optoacoustic contrast agents and their capability to detect disease and recovery progression in clinical settings is provided which includes newly developed exogenous contrast agents to monitor stem cells in real-time for multimodal sensing.

Photostability enhancement of silica-coated gold nanostars for photoacoustic imaging guided photothermal therapy

Gold nanostars (GNSs) are promising contrast agents for simultaneous photothermal therapy and photoacoustic imaging (PAI) owing to their excellent photothermal conversion efficiency. However, GNSs are easily reshaped under transient high-intensity laser pulses, which can cause a rapid shift in the light absorption peak, resulting in a decrease in both therapeutic and monitoring effects. In this work, we synthesized GNSs without toxic surfactants and coated them with a silica shell to retain their shape, thus maintaining their photostability. The excellent performance of these silica-coated GNSs was verified through both in vitro and in vivo PAI experiments. The silica-coated GNSs exhibited a threefold improvement in photoacoustic stability, as compared with the non-coated GNSs. The proposed silica coating method for GNSs was found to improve the photostability of GNSs, making them efficient, safe, and reliable nanoparticles for PAI.

Mesenchymal stem/stromal cells as next-generation drug delivery vehicles for cancer therapeutics

INTRODUCTION

Drug delivery to solid tumors remains a significant therapeutic challenge. Mesenchymal stem/stromal cells (MSCs) home to tumor tissues and can be employed as tumor targeted drug/gene delivery vehicles. Reportedly, therapeutic gene- or anti-cancer drug-loaded MSCs have shown remarkable anti-tumor effects in preclinical studies, and some clinical trials for assessing therapeutic MSCs in patients with cancer have been registered.

AREAS COVERED

In the present review, we first discuss the source and interdonor heterogeneity of MSCs, their tumor-homing mechanism, and the route of MSC administration in MSC-based cancer therapy. We then summarize the therapeutic applications of MSCs as a drug delivery vehicle for therapeutic genes or anti-cancer drugs and the drug delivery mechanism from drug-loaded MSCs to cancer cells.

EXPERT OPINION

Although numerous preclinical studies have revealed significant anti-tumor effects, several clinical trials assessing MSC-based cancer gene therapy have failed to demonstrate corroborative results, documenting limited therapeutic effects. Notably, a successful clinical outcome with MSC-based cancer therapy would require the interdonor heterogeneity of administered MSCs to be resolved, along with improved tumor-homing efficiency and optimized drug delivery efficiency from MSCs to cancer cells.

Selective thermotherapy of tumor by self-regulating photothermal conversion system

One major challenge of photothermal therapy (PTT) is achieving thermal ablation of the tumor without damaging the normal cells and tissues. Here, we designed a self-regulating photothermal conversion system for selective thermotherapy based on self-assembling gold nanoparticles (S-AuNPs) and investigated the selectivity effect using a novel home-made in vitro selective photothermal transformation model and an in vivo skin damaging assessment model. In the in vitro selective photothermal transformation model, laser irradiation selectively increased the temperature of the internal microenvironment (pH 5.5) and resulted in an obvious temperature difference (ΔT ≥ 5 °C) with that of the external environment (pH 7.4). More importantly, in the in vivo skin damaging assessment model, S-AuNPs achieved good tumor inhibition without damaging the normal skin tissue compared with the conventional photothermal material. This work provides not only a novel validation protocol for tumor thermotherapy to achieve the biosafety of specifically killing tumor cells and normal tissue but also an evaluation methodology for other precise therapy for cancers.

Cell-derived biomimetic nanocarriers for targeted cancer therapy: cell membranes and extracellular vesicles

Nanotechnology provides synthetic carriers for cancer drug delivery that protect cargos from degradation, control drug release and increase local accumulation at tumors. However, these non-natural vehicles display poor tumor targeting and potential toxicity and are eliminated by the immune system. Recently, biomimetic nanocarriers have been widely developed based on the concept of ‘mimicking nature.’ Among them, cell-derived biomimetic vehicles have become the focus of bionics research because of their multiple natural functions, such as low immunogenicity, long circulation time and targeting ability. Cell membrane-coated carriers and extracellular vesicles are two widely used cell-based biomimetic materials. Here, this review summarizes the latest progress in the application of these two biomimetic carriers in targeted cancer therapy. Their properties and performance are compared, and their future challenges and development prospects are discussed.

Intravenously Infused Stem Cells for Cancer Treatment

Despite the recent influx of immunotherapies and small molecule drugs to treat tumors, cancer remains a leading cause of death in the United States, in large part due to the difficulties of treating metastatic cancer. Stem cells, which are inherently tumoritropic, provide a useful drug delivery vehicle to target both primary and metastatic tumors. Intravenous infusions of stem cells carrying or secreting therapeutic payloads show significant promise in the treatment of cancer. Stem cells may be engineered to secrete cytotoxic products, loaded with oncolytic viruses or nanoparticles containing small molecule drugs, or conjugated with immunotherapies. Herein we describe these preclinical and clinical studies, discuss the distribution and migration of stem cells following intravenous infusion, and examine both the limitations of and the methods to improve the migration and therapeutic efficacy of tumoritropic, therapeutic stem cells.

Primary Macrophage-Based Microrobots: An Effective Tumor Therapy In Vivo by Dual-Targeting Function and Near-Infrared-Triggered Drug Release

Macrophages (MΦs) have the capability to sense chemotactic cues and to home tumors, therefore presenting a great approach to engineer these cells to deliver therapeutic agents to treat diseases. However, current cell-based drug delivery systems usually use commercial cell lines that may elicit an immune response when injected into a host animal. Furthermore, premature off-target drug release also remains an enormous challenge. Here, we isolated and differentiated MΦs from the spleens of BALB/c mice and developed dual-targeting MΦ-based microrobots, regulated by chemotaxis and an external magnetic field, and had a precise spatiotemporal controlled drug release at the tumor sites in response to the NIR laser irradiation. These microrobots were prepared by coloading citric acid (CA)-coated superparamagnetic nanoparticles (MNPs) and doxorubicin (DOX)-containing thermosensitive nanoliposomes (TSLPs) into the MΦs. CA-MNPs promoted a magnetic targeting function to the microrobots and also permitted photothermal heating in response to the NIR irradiation, triggering drug release from TSLPs. In vitro experiments showed that the microrobots effectively infiltrated tumors in 3D breast cancer tumor spheroids, particularly in the presence of the magnetic field, and effectively induced tumor cell death, further enhanced by the NIR laser irradiation. In vivo experiments confirmed that the application of the magnetic field and NIR laser could markedly inhibit the growth of tumors with a subtherapeutic dose of DOX and a single injection of the microrobots. In summary, the study proposes a strategy for the effective anticancer treatment using the developed microrobots.

MSCs loaded with oncolytic reovirus: migration and in vivo virus delivery potential for evaluating anti-cancer effect in tumor-bearing C57BL/6 mice

Background and aims

Several oncolytic viruses applications have been approved in the clinic or in different phases of clinical trials. However, these methods have some rudimentary problems. Therefore, to enhance the delivery and quality of treatment, considering the advantage of cell carrier-based methods such as Mesenchymal Stem Cells (MSC) have been proposed. This study was designed to evaluate the performance and quality of cancer treatment based on MSCs loaded by oncolytic reovirus in the cancerous C57BL/6 mouse model. Also, we evaluated MSCs migration potency in vitro and in vivo following the oncolytic reovirus infection.

Methods

C57BL/6 mice were inoculated with TC-1 cell lines and tumors were established in the right flank. Mice were systemically treated with reovirus, MSCs-loaded with reovirus, MSCs, and PBS as a control in separated groups. Effects of infected AD-MSCs with reovirus on tumor growth and penetration in the tumor site were monitored. All groups of mice were monitored for two months in order to therapeutic and anticancer potential. After treatments, tumor size alteration and apoptosis rate, as well as cytokine release pattern was assessed.

Results

The results of the current study indicated that the effect of reovirus infection on AD-MSCs is not devastating the migration capacity especially in MOI 1 and 5 while intact cells remain. On the other hand, MSCs play an efficient role as a carrier to deliver oncolytic virus into the tumor site in comparison with systemic administration of reovirus alone. Apoptosis intensity relies on viral titration and passing time. Followed by systemic administration, treatment with oncolytic reovirus-infected AD-MSCs and MSCs alone had shown significant inhibition in tumor growth. Also, treatment by reovirus causes an increase in IFN-γ secretion.

Conclusion

The results of in vitro and in vivo study confirmed the tumor-homing properties of infected AD-MSCs and the significant antitumor activity of this platform. Hence, our results showed that the cell carrier strategy using oncolytic reovirus-loaded AD-MSCs enhanced virus delivery, infiltration, and antitumor activity can be effectively applied in most cancers.

Recent Advancements of Specific Functionalized Surfaces of Magnetic Nano- and Microparticles as a Theranostics Source in Biomedicine

Magnetic nano- and microparticles (MNMPs) belong to a highly versatile class of colloids with actuator and sensor properties that have been broadly studied for their application in theranostics such as molecular imaging and drug delivery. The use of advanced biocompatible, biodegradable polymers and polyelectrolytes as MNMP coating materials is essential to ensure the stability of MNMPs and enable efficient drug release while at the same time preventing cytotoxic effects. In the past years, huge progress has been made in terms of the design of MNMPs. Especially, the understanding of coating formation with respect to control of drug loading and release kinetics on the molecular level has significantly advanced. In this review, recent advancements in the field of MNMP surface engineering and the applicability of MNMPs in research fields of medical imaging, diagnosis, and nanotherapeutics are presented and discussed. Furthermore, in this review the main emphasis is put on the manipulation of biological specimens and cell trafficking, for which MNMPs represent a favorable tool enabling transport processes of drugs through cell membranes. Finally, challenges and future perspectives for applications of MNMPs as theranostic nanomaterials are discussed.

Gold nanoparticles to enhance ophthalmic imaging

The use of gold nanoparticles as diagnostic tools is burgeoning, especially in the cancer community with a focus on theranostic applications to both cancer diagnosis and treatment. Gold nanoparticles have also demonstrated great potential for use in diagnostic and therapeutic approaches in ophthalmology. Although many ophthalmic imaging modalities are available, there is still a considerable unmet need, in particular for ophthalmic molecular imaging for the early detection of eye disease before morphological changes are more grossly visible. An understanding of how gold nanoparticles are leveraged in other fields could inform new ways they could be utilized in ophthalmology. In this paper, we review current ophthalmic imaging techniques and then identify optical coherence tomography (OCT) and photoacoustic imaging (PAI) as the most promising technologies amenable to the use of gold nanoparticles for molecular imaging. Within this context, the development of gold nanoparticles as OCT and PAI contrast agents are reviewed, with the most recent developments described in detail.

Outstanding Drug-Loading/Release Capacity of Hollow Fe-Metal-Organic Framework-Based Microcapsules: A Potential Multifunctional Drug-Delivery Platform

Owing to their characteristic structures, metal-organic frameworks (MOFs) are considered as the leading candidate for drug-delivery materials. However, controlling the synthesis of MOFs with uniform morphology and high drug-loading/release efficiencies is still challenging, which greatly limits their applications and promotion. Herein, a multifunctional MOF-based drug-delivery system (DDS) with a controlled pore size of 100-200 nm for both therapeutic and bioimaging purposes was successfully synthesized in one step. Fe-MOF-based microcapsules were synthesized through a competitive coordination method, which was profited from the intrinsic coordination characteristics of the Fe element and the host-guest supramolecular interactions between Fe³⁺ and polyoxometalates anions. This as-synthesized macroporous DDS could greatly increase the drug-loading/release rate (77%; 83%) and serve as a magnetic resonance (MR) contrast agent. Because an Fe-containing macroporous DDS presents ultrahigh drug loading/release, the obtained 5-FU/Fe-MOF-based microcapsules displayed good biocompatibility, extremely powerful inhibition of tumor growth, and satisfactory MR imaging capability. Given all these advantages, this study integrates high therapeutic effect and diagnostic capability via a simple and effective morphology-controlling strategy, aiming at further facilitating the applications of MOFs in multifunctional drug delivery.

Mesenchymal Stem Cells Functionalized Sonodynamic Treatment for Improving Therapeutic Efficacy and Compliance of Orthotopic Oral Cancer

Despite multiple treatment options being available, many critical challenges are still ongoing in the treatment of oral squamous cell carcinoma (OSCC). Particularly, the major hurdle is to avoid facial disfigurement and oral function disability during treatment. Herein, nanoengineered mesenchymal stem cells (MSCs) are developed as a supersonosensitizer, named M/LPV/O₂ , for improving nondestructive sonodynamic therapy (SDT) against OSCC along with good therapeutic compliance. M/LPV/O₂ is composed of an MSCs membrane functionalized liposomal formulation of oxygen-loading perfluorocarbon and sonosensitizer verteporfin (M/LPV/O₂ ), which can not only increase circulation and targeting efficacy but also supply oxygen to overcome tumor-hypoxia-associated resistance in SDT, resulting in enhanced therapeutic outcomes in vitro and in vivo. It is identified that M/LPV/O₂ effectively stimulates the generation of reactive oxygen species even in hypoxic conditions, and consequently tremendously induces cancer cell death. In addition, M/LPV/O₂ displays good tumor accumulation and penetration under ultrasound stimulation, and efficiently induces tumor inhibition and even abrogation, leading to prolonged survival of tumor-bearing mice. Importantly, M/LPV/O₂ -based SDT exhibits minimal systemic adverse effects and successfully maintains oral functions with no facial tissue damage. Therefore, these studies provide a promising therapeutic strategy for OSCC, which has a potential to enhance life quality and compliance after treatment.

A Smart Nanoparticle-Laden and Remote-Controlled Self-Destructive Macrophage for Enhanced Chemo/Chemodynamic Synergistic Therapy

Macrophages are known to penetrate tumor central hypoxic areas and hold great potential in cancer drug delivery. However, it remains a big challenge for current macrophage-based drug delivery systems (MDDSs) to prevent premature drug leakage and sufficiently release the therapeutics in tumor sites. Moreover, these MDDSs would encounter drug resistance and a hypoxic microenvironment in solid tumors, which further compromised their therapeutic efficacy. Herein, by internalizing a smart nanoparticle (doxorubicin (DOX)-loaded mesoporous carbon nanosphere wrapped with MnO₂ shell) into macrophages, a macrophage vehicle (MMDM) is developed for enhanced chemo/chemodynamic synergistic therapy. The resulting MMDM could avoid premature drug leakage-induced cell dysfunction and maximally maintain cell viability. After accumulating in tumor tissues, the MMDM could be destroyed under a near-infrared laser to sufficiently release the nanoparticle out of the carrier macrophages. The released nanoparticle could then decompose H₂O₂ to generate O₂ in the tumor microenvironment to relieve tumor hypoxia. Meanwhile, the MnO₂ shell of the nanoparticle is reduced to Mn²⁺ by intracellular glutathione, triggering the release of DOX and subsequently resulting in an enhanced Mn²⁺-mediated Fenton-like reaction. This study provides an intriguing strategy to macrophage-based delivery systems for enhanced chemo/chemodynamic synergistic therapy.

Application of Nanomaterials in Biomedical Imaging and Cancer Therapy

Nanomaterials, such as nanoparticles, nanorods, nanosphere, nanoshells, and nanostars, are very commonly used in biomedical imaging and cancer therapy. They make excellent drug carriers, imaging contrast agents, photothermal agents, photoacoustic agents, and radiation dose enhancers, among other applications. Recent advances in nanotechnology have led to the use of nanomaterials in many areas of functional imaging, cancer therapy, and synergistic combinational platforms. This review will systematically explore various applications of nanomaterials in biomedical imaging and cancer therapy. The medical imaging modalities include magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission computerized tomography, optical imaging, ultrasound, and photoacoustic imaging. Various cancer therapeutic methods will also be included, including photothermal therapy, photodynamic therapy, chemotherapy, and immunotherapy. This review also covers theranostics, which use the same agent in diagnosis and therapy. This includes recent advances in multimodality imaging, image-guided therapy, and combination therapy. We found that the continuous advances of synthesis and design of novel nanomaterials will enhance the future development of medical imaging and cancer therapy. However, more resources should be available to examine side effects and cell toxicity when using nanomaterials in humans.

CD271 antibody-functionalized HGNs for targeted photothermal therapy of osteosarcoma stem cells

Cancer stem cells (CSCs) are considered to maintain the vitality of tumor cell populations through self-renewal and infinite proliferation, but their accessibility is still under investigation. In addition, CSCs are more resistant to chemotherapy and radiotherapy compared with common tumor cells. This study aimed to develop a kind of novel and feasible nanomaterial for targeted photothermal ablation of osteosarcoma stem cells, which could be a promising anticancer strategy. The osteosarcoma stem cells were extracted by serum-free culture and we further verified the stem cell properties. We evaluated the expression of CD271 by flow cytometry. PEGylated multifunctional hollow gold nanospheres (HGNs) were prepared based on CD271 monoclonal antibody. Bifunctional SH-PEG-COOH was used to facilitate the covalent linkage between HGNs and antibody. The efficient uptake and distribution of the functionalized HGNs were investigated using ICP-MS and TEM. Morphological studies and quantitative apoptosis evaluation were performed to detect the effect of photothermal therapy (PTT). Afterwards, we explored the possible mechanism by which PTT induced targeted killing of cancer stem cells. Osteosarcoma cells isolated from serum-free culture were detected to show stem cell properties. CD271 was found to be a potential novel surface marker for osteosarcoma stem cells. By conjugating with CD271 monoclonal antibody, these biomimetic nanoparticles can be targeted and absorbed by osteosarcoma stem cells. HGNs-PEG-CD271 achieved excellent cell viability inhibition compared with non-targeted PEGylated HGNs upon near-infrared (NIR) laser irradiation. The mechanism of targeted killing may be related to the apoptosis pathway and DNA double-strand injuries. CD271 was considered to be a surface biomarker for osteosarcoma stem cells. Functionalized HGNs based on CD271 antibody exhibited excellent potential for targeted PTT, which may be a promising strategy for osteosarcoma treatment.