Bioinspired Multifunctional Melanin-Based Nanoliposome for Photoacoustic/Magnetic Resonance Imaging-Guided Efficient Photothermal Ablation of Cancer

PEGylated Nanoliposomes Encapsulated with Anticancer Drugs for Breast and Prostate Cancer Therapy: An Update

There are different types of cancer treatments, including surgery, radiotherapy, and chemotherapy. However, the complexity of cancer has resulted in treatment challenges to medicinal scientists and a socio-economic burden to the public health system globally. The pharmacological limitations associated with the current conventional anticancer drugs include lack of specificity, poor bioavailability, toxicity, drug resistance, and poor delivery mechanisms, which make cancer treatment challenging. Thus, the number of cancer cases is escalating rapidly, especially breast and prostate cancer in women and men, respectively. The application of nanoformulations is gaining momentum for treating different cancer types. However, they also exhibit challenges that must be addressed for effective cancer treatment. Nanoliposomes are nanoformulations that are widely explored for cancer treatment with interesting therapeutic outcomes. They have been functionalized with PEG to further improve their therapeutic outcomes. Hence, this review provides an update on PEGylated nanoliposomes loaded with anticancer drugs for the treatment of breast and prostate cancer, focusing on pre-clinical studies published in the last decade (2015 to 2024) to reflect the recent advancements made in the design of PEGylation nanoliposomes. Highlights of the clinically and commercially available PEGylation nanoliposomes are also presented in this review.

Magnetoresponsive liposomes applications in nanomedicine: A comprehensive review

Safe and effective cancer therapy requires a suitable nanocarrier that can target particular sites, such as cancer cells, in a selective manner. With the tremendous growth in nanotechnology, liposomes, among various competing nanocarriers, have shown promising advances in cancer therapy. Magnetic nanoparticles and metal ions are wide-reaching candidates for conferring magnetic properties and for incorporation into liposomes. Combining liposomes with magnetic structures enables construction of magnetoresponsive liposomes, allowing stimuli-responsiveness to an alternating magnetic field, magnetic targeting, and tracking by magnetic resonance imaging, which could all occur in parallel. This review presents a comprehensive analysis of the practical advances and novel aspects of design, synthesis and engineering magnetoresponsive liposomes, emphasizing their diverse properties for various applications. Our work explores the innovative uses of these structures, extending beyond drug delivery to include smart contrast agents, cell labeling, biosensing, separation, and filtering. By comparing new findings with earlier studies, we showcase significant improvements in efficiency and uncover new potentials, setting a new benchmark for future research in the field of magnetoresponsive liposomes.

Salidroside sensitizes Triple-negative breast cancer to ferroptosis by SCD1-mediated lipogenesis and NCOA4-mediated ferritinophagy

INTRODUCTION

Triple-negative breast cancer (TNBC) is the primary cause of breast cancer-induced death in women. Literature has confirmed the benefits of Salidroside (Sal) in treating TNBC. However, the study about potential therapeutic targets and mechanisms of Sal-anchored TNBC remains limited.

OBJECTIVE

This study was designed to explore the main targets and potential mechanisms of Sal against TNBC.

METHODS

Network pharmacology, bioinformatics, and machine learning algorithm strategies were integrated to examine the role, potential targets, and mechanisms of the Sal act in TNBC. MDA-MB-231 cells and tumor-bearing nude mice were chosen for in vitro and in vivo experimentation. Cell viability and cytotoxicity were determined using CCK-8, LDH test, and Calcein-AM/PI staining. Antioxidant defense, lipid peroxidation, and iron metabolism were explored using glutathione, glutathione peroxidase, malondialdehyde (MDA), C11-BODIPY 581/591 probe, and FerroOrange dye. Glutathione peroxidase 4 (GPX4) or stearoyl-CoA desaturase 1 (SCD1) overexpression or nuclear receptor co-activator 4 (NCOA4) deficiency was performed to demonstrate the mechanism of Sal on TNBC.

RESULTS

The prediction results confirmed that 22 ferroptosis-related genes were identified in Sal and TNBC, revealing that the potential mechanism of the Sal act on TNBC was linked with ferroptosis. Besides, these genes were mainly involved in the mTOR, PI3K/AKT, and autophagy signaling pathway by functional enrichment analysis. The in vitro validation results confirmed that Sal inhibited TNBC cell proliferation by modulating ferroptosis via elevation of intracellular Fe2+ and lipid peroxidation. Mechanistically, Sal sensitized TNBC cells to ferroptosis by inhibiting the PI3K/AKT/mTOR axis, thereby suppressing SCD1-mediated lipogenesis of monounsaturated fatty acids to induce lipid peroxidation, additionally facilitating NCOA4-mediated ferritinophagy to increase intracellular Fe2+ content. The GPX4 or SCD1 overexpression or NCOA4 deficiency results further supported our mechanistic studies. In vivo experimentation confirmed that Sal is vital for slowing down tumor growth by inducing ferroptosis.

CONCLUSIONS

Overall, this study elucidates TNBC pathogenesis closely linked to ferroptosis and identifies potential biomarkers in TNBC. Meanwhile, the study elucidates that Sal sensitizes TNBC to ferroptosis by SCD1-mediated lipogenesis and NCOA4-mediated ferritinophagy, regulated by PI3K/AKT/mTOR signaling pathways. Our findings provide a theoretical basis for applying Sal to treat TNBC.

The Quest for Two-Dimensional MBenes: From Structural Evolution to Solar-Driven Hybrid Systems for Water-Fuel-Energy Generation and Phototherapy

The field of 2D materials has advanced significantly with the emergence of MBenes, a new material derived from the MAX phases family, a novel class of materials that originates from the MAX phases family. Herein, this article explores the unique characteristics and morphological variations of MBenes, offering a comprehensive overview of their structural evolution. First, the discussion explores the evolutionary period of 2D MBenes associated with the several techniques for synthesizing, modifying, and characterizing MBenes to tailor their structure and enhance their functionality. The focus then shifts to the defect chemistry of MBenes, electronic, catalytic, and photothermal properties which play a crucial role in designing multifunctional solar-driven hybrid systems. Second, the recent advancements and potentials of 2D MBenes in solar-driven hybrid systems e.g. photo-electro catalysis, hybrid solar evaporators for freshwater and thermoelectric generators, and phototherapy, emphasizing their crucial significance in tackling energy and environmental issues, are explored. The study further explores the fundamental principles that regulate the improved photocatalytic and photothermal characteristics of MBenes, highlighting their promise for effective utilization of solar energy and remediation of the environment. The study also thoroughly assesses MBenes' scalability, stability, and cost effectiveness in solar-driven systems. Current insights and future directions allow researchers to utilize MBenes for sustainable and varied applications. This review regarding MBenes will be valuable to early researchers intrigued with synthesizing and utilizing 2D materials for solar-powered water-energy-fuel and phototherapy systems.

Non-pigmented laser hair removal mediated via sepia melanin nanoparticles: in vivo study on albino mice

OBJECTIVES

Melanin is considered the main chromophore for laser hair removal. Due to a lack of laser-absorbing chromophores, removing non-pigmented hair with laser is quite problematic with unsatisfactory outcomes. This problem could be solved by delivering more melanin to the area around the hair follicle and enhancing that area as a target for light absorption. The insolubility of Sepia melanin as an exogenous dye, in most solvents, limits its bioavailability and thus its clinical use.

METHODS

In our study, to overcome the solubility problems and increase the bioavailability of melanin for biomedical and cosmetic applications, natural sepia melanin was loaded in different nano-delivery systems (spanlastics and transfersomes) to be delivered to the hair follicles. The different formulations of melanin were prepared and characterized. In vivo skin deposition and histopathological studies were conducted on albino mice.

RESULTS

Transmission electron microscopy (TEM) showed the spherical shape of the prepared vesicles with an average particle size of 252 and 262 nm and zeta potential of -22.5 and -35 mV for melanin spanlastics and melanin transfersomes, respectively. Histopathological examination of hair follicles and pilosebaceous glands for the irradiated and non-irradiated albino mice skin was studied post the application of the prepared formulations topically and subcutaneously. Qualitative statistical analysis was conducted and melanin transfersomes and melanin spanlastics showed significant damage to pilosebaceous glands and hair follicles with a p-value of 0.031 and 0.009 respectively.

CONCLUSION

Melanin nanovesicles as transfersomes and spanlastics could be considered a promising approach for the removal of non-pigmented hair.

Melanin-Ce6-loaded polydopamine nanoparticles-based enhanced phototherapy for B16 melanoma cancer cells

Melanoma is one of the most aggressive and lethal types of cancer owing to its metastatic propensity and chemoresistance property. An alternative therapeutic option is photodynamic and photothermal therapies (PDT/PTT), which employ near-infrared (NIR) light to generate heat and reactive oxygen species (ROS). As per previous reports, Melanin (Mel), and its synthetic analogs (i.e. polydopamine nanoparticles) can induce NIR light-mediated heat energy, thereby selectively targeting and ameliorating cancer cells. Similarly, chlorin e6 (Ce6) also has high ROS generation ability and antitumor activity against various types of cancer. Based on this tenet, In the current study, we have encapsulated Mel-Ce6 in a polydopamine (PDA) nanocarrier (MCP NPs) synthesized by the oxidation polymerization method. The hydrodynamic diameter of the synthesized spherical MCP NPs was 139 ± 10 nm. The MCP NPs, upon irradiation with NIR 690 nm laser for 6 min, showed photothermal efficacy of more than 50 °C. Moreover, the red fluorescence in the MCP NPs due to Ce6 can be leveraged for diagnostic purposes. Further, the MCP NPs exhibited considerable biocompatibility with the L929 cell line and exerted nearly 70% ROS-mediated cytotoxicity on the B16 melanoma cell line after the laser irradiation. Thus, the prepared MCP NPs could be a promising theranostic agent for treating the B16 melanoma cancer.

The mitochondria-targeted Kaempferol nanoparticle ameliorates severe acute pancreatitis

Kaempferol (KA), an natural antioxidant of traditional Chinese medicine (TCM), is extensively used as the primary treatment for inflammatory digestive diseases with impaired redox homeostasis. Severe acute pancreatitis (SAP) was exacerbated by mitochondrial dysfunction and abundant ROS, which highlights the role of antioxidants in targeting mitochondrial function. However, low bioavailability and high dosage of KA leading to unavoidable side effects limits clinical transformation. The mechanisms of KA with poor bioavailability largely unexplored, hindering development of the efficient strategies to maximizing the medicinal effects of KA. Here, we engineered a novel thioketals (TK)-modified based on DSPE-PEG2000 liposomal codelivery system for improving bioavailability and avoiding side effects (denotes as DSPE-TK-PEG2000-KA, DTM@KA NPs). We demonstrated that the liposome exerts profound impacts on damaging intracellular redox homeostasis by reducing GSH depletion and activating Nrf2, which synergizes with KA to reinforce the inhibition of inadequate fission, excessive mitochondrial fusion and impaired mitophagy resulting in inflammation and apoptosis; and then, the restored mitochondrial homeostasis strengthens ATP supply for PAC renovation and homeostasis. Interestingly, TK bond was proved as the main functional structure to improve the above efficacy of KA compared with the absence of TK bond. Most importantly, DTM@KA NPs obviously suppresses PAC death with negligible side effects in vitro and vivo. Mechanismly, DTM@KA NPs facilitated STAT6-regulated mitochondrial precursor proteins transport via interacting with TOM20 to further promote Drp1-dependent fission and Pink1/Parkin-regulated mitophagy with enhanced lysosomal degradation for removing damaged mitochondria in PAC and then reduce inflammation and apoptosis. Generally, DTM@KA NPs synergistically improved mitochondrial homeostasis, redox homeostasis, energy metabolism and inflammation response via regulating TOM20-STAT6-Drp1 signaling and promoting mitophagy in SAP. Consequently, such a TCM's active ingredients-based nanomedicine strategy is be expected to be an innovative approach for SAP therapy.

Repurposing Disulfiram to Combat Acute Respiratory Distress Syndrome with Targeted Delivery by LET-Functionalized Nanoplatforms

Acute respiratory distress syndrome (ARDS) is a serious respiratory condition characterized by a damaged pulmonary endothelial barrier that causes protein-rich lung edema, an influx of proinflammatory cells, and treatment-resistant hypoxemia. Damage to pulmonary endothelial cells and inflammation are pivotal in ARDS development with a key role played by endothelial cell pyroptosis. Disulfiram (DSF), a drug that has long been used to treat alcohol addiction, has recently been identified as a potent inhibitor of gasdermin D (GSDMD)-induced pore formation and can thus prevent pyroptosis and inflammatory cytokine release. These findings indicate that DSF is a promising treatment for inflammatory disorders. However, addressing the challenge posed by its intrinsic physicochemical properties, which hinder intravenous administration, and effective delivery to pulmonary vascular endothelial cells are crucial. Herein, we used biocompatible liposomes incorporating a lung endothelial cell-targeted peptide (CGSPGWVRC) to produce DSF-loaded nanoparticles (DTP-LET@DSF NPs) for targeted delivery and reactive oxygen species-responsive release facilitated by the inclusion of thioketal (TK) within the liposomal structure. After intravenous administration, DTP-LET@DSF NPs exhibited excellent cytocompatibility and minor systemic toxicity, effectively inhibited pyroptosis, mitigated lipopolysaccharide (LPS)-induced ARDS, and prevented cytokine storms resulting from excessive immune reactions in ARDS mice. This study presents a straightforward nanoplatform for ARDS treatment that potentially paves the way for the clinical use of this nanomedicine.

Recent Trends in Bio-nanomaterials and Non-invasive Combinatorial Approaches of Photothermal Therapy against Cancer

In 2020, approximately 10 million deaths worldwide were attributed to cancer, making it the primary cause of death globally. Photothermal therapy (PTT) is one of the novel ways to treat and abolish cancer. PTT significantly impacts cancer theranostics compared to other therapies like surgery, chemotherapy, and radiotherapy due to its remarkable binding capability to tumor sites and lower invasiveness into normal healthy tissues. PTT relies on photothermal agents (PTAs), which generate heat by absorbing the near-infrared (NIR) light and destroying cancer cells. Several PTT agents remain longer in the reticuloendothelial system (RES) and induce toxicity, restricting their use in the biomedical field. To overcome this problem, the usage of biodegradable nano-photothermal agents is required. This review has discussed the PTT mechanism of action and different types of novel bio-nanomaterials used for PTT. We also focussed on the combinatorial effects of PTT with other cancer therapies and their effect on human health. The role of LED lights and mild hypothermia in PTT has been discussed briefly in this review.

Cell membrane-coated biomimetic nanomedicines: productive cancer theranostic tools

As the second-leading cause of human death, cancer has drawn attention in the area of biomedical research and therapy from all around the world. Certainly, the development of nanotechnology has made it possible for nanoparticles (NPs) to be used as a carrier for delivery systems in the treatment of tumors. This is a biomimetic approach established to craft remedial strategies comprising NPs cloaked with membrane obtained from various natural cells like blood cells, bacterial cells, cancer cells, etc. Here we conduct an in-depth exploration of cell membrane-coated NPs (CMNPs) and their extensive array of applications including drug delivery, vaccination, phototherapy, immunotherapy, MRI imaging, PET imaging, multimodal imaging, gene therapy and a combination of photothermal and chemotherapy. This review article provides a thorough summary of the most recent developments in the use of CMNPs for the diagnosis and treatment of cancer. It critically assesses the state of research while recognizing significant accomplishments and innovations. Additionally, it indicates ongoing problems in clinical translation and associated queries that warrant deeper research. By doing so, this study encourages creative thinking for future projects in the field of tumor therapy using CMNPs while also educating academics on the present status of CMNP research.

Melanin/melanin-like nanoparticles: As a naturally active platform for imaging-guided disease therapy

The development of biocompatible and efficient nanoplatforms that combine diagnostic and therapeutic functions is of great importance for precise disease treatment. Melanin, an endogenous biopolymer present in living organisms, has attracted increasing attention as a versatile bioinspired functional platform owing to its unique physicochemical properties (e.g., high biocompatibility, strong chelation of metal ions, broadband light absorption, high drug binding properties) and inherent antioxidant, photoprotective, anti-inflammatory, and anti-tumor effects. In this review, the fundamental physicochemical properties and preparation methods of natural melanin and melanin-like nanoparticles were outlined. A systematical description of the recent progress of melanin and melanin-like nanoparticles in single, dual-, and tri-multimodal imaging-guided the visual administration and treatment of osteoarthritis, acute liver injury, acute kidney injury, acute lung injury, brain injury, periodontitis, iron overload, etc. Was then given. Finally, it concluded with a reasoned discussion of current challenges toward clinical translation and future striving directions. Therefore, this comprehensive review provides insight into the current status of melanin and melanin-like nanoparticles research and is expected to optimize the design of novel melanin-based therapeutic platforms and further clinical translation.

Biogenic Imaging Contrast Agents

Imaging contrast agents are widely investigated in preclinical and clinical studies, among which biogenic imaging contrast agents (BICAs) are developing rapidly and playing an increasingly important role in biomedical research ranging from subcellular level to individual level. The unique properties of BICAs, including expression by cells as reporters and specific genetic modification, facilitate various in vitro and in vivo studies, such as quantification of gene expression, observation of protein interactions, visualization of cellular proliferation, monitoring of metabolism, and detection of dysfunctions. Furthermore, in human body, BICAs are remarkably helpful for disease diagnosis when the dysregulation of these agents occurs and can be detected through imaging techniques. There are various BICAs matched with a set of imaging techniques, including fluorescent proteins for fluorescence imaging, gas vesicles for ultrasound imaging, and ferritin for magnetic resonance imaging. In addition, bimodal and multimodal imaging can be realized through combining the functions of different BICAs, which helps overcome the limitations of monomodal imaging. In this review, the focus is on the properties, mechanisms, applications, and future directions of BICAs.

Yb-Gd Codoped Hydroxyapatite as a Potential Contrast Agent for Tumor-Targeted Biomedical Applications

Recently, various nanomaterials based on hydroxyapatite (HAp) have been developed for bioimaging applications. In particular, HAp doped with rare-earth elements has attracted significant attention, owing to its enhanced bioactivity and imaging properties. In this study, the wet precipitation method was used to synthesize HAp codoped with Yb and Gd. The synthesized Ybx-Gdx-HAp nanoparticles (NPs) were characterized via various techniques to analyze the crystal phase, functional groups, thermal characteristics, and particularly, the larger surface area. The IR783 fluorescence dye and a folic acid (FA) receptor were conjugated with the synthesized Ybx-Gdx-HAp NPs to develop an effective imaging contrast agent. The developed FA/IR783/Yb-Gd-HAp nanomaterial exhibited improved contrast, sensitivity, and tumor-specific properties, as demonstrated by using the customized LUX 4.0 fluorescence imaging system. An in vitro cytotoxicity study was performed to verify the biocompatibility of the synthesized NPs using MTT assay and fluorescence staining. Photodynamic therapy (PDT) was also applied to determine the photosensitizer properties of the synthesized Ybx-Gdx-HAp NPs. Further, reactive oxygen species generation was confirmed by Prussian blue decay and a 2',7'-dichlorofluorescin diacetate study. Moreover, MDA-MB-231 breast cancer cells were used to evaluate the efficiency of Ybx-Gdx-HAp NP-supported PDT.

Biosynthetic Melanin/Ce6-Based Photothermal and Sonodynamic Therapies Significantly Improved the Anti-Tumor Efficacy

Photothermal therapy (PTT) and sonodynamic therapy (SDT) are becoming promising therapeutic modalities against various tumors in recent years. However, the single therapeutic modality with SDT or PTT makes it difficult to achieve a satisfactory anti-tumor outcome due to their own inherent limitations, such as poor tissue penetration for the near-infrared (NIR) laser and the limited cytotoxic reactive oxygen species (ROS) generated from conventional sonosensitizers irradiated by ultrasound (US). Here, we successfully biosynthesized melanin with a controllable particle size with genetically engineered bacteria harboring a heat-inducible gene circuit. The biosynthetic melanin with 8 nm size and chlorin e6 (Ce6) was further encapsulated into liposomes and obtained SDT/PTT dual-functional liposomes (designated as MC@Lip). The resulting MC@Lip had an approximately 100 nm particle size, with 74.71% ± 0.54% of encapsulation efficiency for melanin and 94.52% ± 0.78% for Ce6. MC@Lip exhibited efficient 1O2 production and photothermal conversion capability upon receiving irradiation by US and NIR laser, producing significantly enhanced anti-tumor efficacy in vitro and in vivo. Especially, US and NIR laser irradiation of tumors received with MC@Lip lead to complete tumor regression in all tested tumor-bearing mice, indicating the great advantage of the combined use of SDT and PTT. More importantly, MC@Lip possessed good photoacoustic (PA) and fluorescence dual-modal imaging performance, making it possible to treat tumors under imaging guidance. Our study provides a novel approach to synthesize a melanin nanoparticle with controllable size and develops a promising combined SDT/PTT strategy to treat tumors.

Advances of medical nanorobots for future cancer treatments

Early detection and diagnosis of many cancers is very challenging. Late stage detection of a cancer always leads to high mortality rates. It is imperative to develop novel and more sensitive and effective diagnosis and therapeutic methods for cancer treatments. The development of new cancer treatments has become a crucial aspect of medical advancements. Nanobots, as one of the most promising applications of nanomedicines, are at the forefront of multidisciplinary research. With the progress of nanotechnology, nanobots enable the assembly and deployment of functional molecular/nanosized machines and are increasingly being utilized in cancer diagnosis and therapeutic treatment. In recent years, various practical applications of nanobots for cancer treatments have transitioned from theory to practice, from in vitro experiments to in vivo applications. In this paper, we review and analyze the recent advancements of nanobots in cancer treatments, with a particular emphasis on their key fundamental features and their applications in drug delivery, tumor sensing and diagnosis, targeted therapy, minimally invasive surgery, and other comprehensive treatments. At the same time, we discuss the challenges and the potential research opportunities for nanobots in revolutionizing cancer treatments. In the future, medical nanobots are expected to become more sophisticated and capable of performing multiple medical functions and tasks, ultimately becoming true nanosubmarines in the bloodstream.

Recent Advances and Progress on Melanin: From Source to Application

Melanin is a biological pigment formed by indoles and phenolic compounds. It is widely found in living organisms and has a variety of unique properties. Due to its diverse characteristics and good biocompatibility, melanin has become the focus in the fields of biomedicine, agriculture, the food industry, etc. However, due to the wide range of melanin sources, complex polymerization properties, and low solubility of specific solvents, the specific macromolecular structure and polymerization mechanism of melanin remain unclear, which significantly limits the further study and application of melanin. Its synthesis and degradation pathways are also controversial. In addition, new properties and applications of melanin are constantly being discovered. In this review, we focus on the recent advances in the research of melanin in all aspects. Firstly, the classification, source, and degradation of melanin are summarized. Secondly, a detailed description of the structure, characterization, and properties of melanin is followed. The novel biological activity of melanin and its application is described at the end.

Self-assembled surfactant-based nanoparticles as a platform for solubilization and enhancement of the photothermal activity of sepia melanin

Background

Sepia melanin (SM) is a natural photothermal biopolymer. Its biomedical applications are limited due to its poor solubility and bioavailability. This study aims to prepare a soluble formulation of sepia melanin to enhance its solubility, in turn, its bioavailability, and its use in photothermal therapy of cancer. SM was extracted from a sepia ink sac and prepared as insoluble powdered (SM) which is identified by FTIR, 1H-NMR, thermogravimetric analysis (TGA), and scanning electron microscope. SM was self-assembled using tween 80 into dispersed nanoparticles (SM-NP-Tw). The prepared SM-NP-Tw were fully characterized. The photothermal performance of SM-NP-Tw was assessed. Dark and photocytotoxicity of SM-NP-Tw was studied on HepG2 cells using two wavelengths (660 nm and 820 nm).

Results

The insoluble powdered (SM) exhibited a spherical nanoparticle-like shape as revealed by scanning electron microscope and was soluble only in an alkaline aqueous solution. TGA of SM showed high resistance to thermal degradation indicating good thermal stability. The prepared SM-NP-Tw exhibited a spherical shape with mean sizes of 308 ± 86 nm and a zeta potential of − 25 mv. The cell viability decreased significantly upon increasing the concentration and upon radiation at 820 nm. The results of UV–Vis spectroscopy and the photothermal performance revealed that melanin can absorb light in a wide range of wavelengths including near the IR region; thus, it can emit sufficient heat to kill cells through the photoheat conversion effects.

Conclusion

Sepia melanin nanoparticles self-assembled into tween-based nanostructures could be a promising natural platform for photothermal cancer therapy.

Recent Progress Toward Imaging Application of Multifunction Sonosensitizers in Sonodynamic Therapy

Sonodynamic therapy (SDT) is a rapidly developing non-surgical therapy that initiates sensitizers’ catalytic reaction using ultrasound, showing great potential for cancer treatment due to its high safety and non-invasive nature. In addition, recent research has found that using different diagnostic and therapeutic methods in tandem can lead to better anticancer outcomes. Therefore, as essential components of SDT, sonosensitizers have been extensively explored to optimize their functions and integrate multiple medical fields. The review is based on five years of articles evaluating the combined use of SDT and imaging in treating cancer. By developing multifunctional sonosensitive particles that combine imaging and sonodynamic therapy, we have integrated diagnosis into the treatment of precision medicine applications, improving SDT cell uptake and antitumor efficacy utilizing different tumour models. This paper describes the imaging principle and the results of cellular and animal imaging of the multifunctional sonosensitizers. Efforts are made in this paper to provide data and design references for future SDT combined imaging research and clinical application development and to provide offer suggestions.

PAI/MRI Visualization of Tumor Derived Cellular Microvesicles with Endogenous Biopolymer Nanoparticles Modification

Background

Tumor derived cellular microvesicles (TDMVs), as excellent drug delivery vehicles in vivo, play an important role in the treatment of cancers. However, it is difficult to obtain intuitional biodistribution behavior and internalization mechanisms of TDMVs in vivo. Thus, it is very urgent and important to establish a stable and reliable visualization technology to track the biological behavior and function of TDMVs. As an endogenous biopolymer, melanin possesses natural biocompatibility and biodegradability, and various biological imaging could be realized by modifying it. Therefore, melanin-based nanoparticles are excellent candidates for in vivo visualization of TDMVs.

Methods

In this work, the biodistribution and metabolic behavior of TDMVs were visualized by dual-modality imaging with PAI and MRI after incubation with gadolinium ion-chelated melanin nanoparticles.

Results

In this study, MRI and PAI dual-modality imaging of the in vivo distribution behavior of TDMVs was achieved with the help of MNP-Gd. The good targeting ability of TDMVs at the homologous tumor site was observed, and their distribution and metabolism behavior in the whole body were studied at the meantime. The results indicated that TDMVs preferentially accumulated in syngeneic tumor sites and liver regions after intravenous injection and were eventually metabolized by the kidneys over time.

Conclusion

This work proposed a novel dual-modal imaging strategy for the visualization of TDMVs, which is of great significance for further understanding the biological mechanisms of extracellular vesicles.

ROS-responsive liposomes as an inhaled drug delivery nanoplatform for idiopathic pulmonary fibrosis treatment via Nrf2 signaling

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic disease with pathophysiological characteristics of transforming growth factor-β (TGF-β), and reactive oxygen species (ROS)-induced excessive fibroblast-to-myofibroblast transition and extracellular matrix deposition. Macrophages are closely involved in the development of fibrosis. Nuclear factor erythroid 2 related factor 2 (Nrf2) is a key molecule regulating ROS and TGF-β expression. Therefore, Nrf2 signaling modulation might be a promising therapy for fibrosis. The inhalation-based drug delivery can reduce systemic side effects and improve therapeutic effects, and is currently receiving increasing attention, but direct inhaled drugs are easily cleared and difficult to exert their efficacy. Therefore, we aimed to design a ROS-responsive liposome for the Nrf2 agonist dimethyl fumarate (DMF) delivery in the fibrotic lung. Moreover, we explored its therapeutic effect on pulmonary fibrosis and macrophage activation.

RESULTS

We synthesized DMF-loaded ROS-responsive DSPE-TK-PEG@DMF liposomes (DTP@DMF NPs). DTP@DMF NPs had suitable size and negative zeta potential and excellent capability to rapidly release DMF in a high-ROS environment. We found that macrophage accumulation and polarization were closely related to fibrosis development, while DTP@DMF NPs could attenuate macrophage activity and fibrosis in mice. RAW264.7 and NIH-3T3 cells coculture revealed that DTP@DMF NPs could promote Nrf2 and downstream heme oxygenase-1 (HO-1) expression and suppress TGF-β and ROS production in macrophages, thereby reducing fibroblast-to-myofibroblast transition and collagen production by NIH-3T3 cells. In vivo experiments confirmed the above findings. Compared with direct DMF instillation, DTP@DMF NPs treatment presented enhanced antifibrotic effect. DTP@DMF NPs also had a prolonged residence time in the lung as well as excellent biocompatibility.

CONCLUSIONS

DTP@DMF NPs can reduce macrophage-mediated fibroblast-to-myofibroblast transition and extracellular matrix deposition to attenuate lung fibrosis by upregulating Nrf2 signaling. This ROS-responsive liposome is clinically promising as an ideal delivery system for inhaled drug delivery.

Surfactant-Stripped Semiconducting Polymer Micelles for Tumor Theranostics and Deep Tissue Imaging in the NIR-II Window

Photoacoustic imaging (PA) in the second near infrared (NIR-II) window presents key advantages for deep tissue imaging owing to reduced light scattering and low background signal from biological structures. Here, a thiadiazoloquinoxaline-based semiconducting polymer (SP) with strong absorption in the NIR-II region is reported. After encapsulation of SP in Pluronic F127 (F127) followed by removal of excess surfactant, a dual functional polymer system named surfactant-stripped semiconductor polymeric micelles (SSS-micelles) are generated with water solubility, storage stability, and high photothermal conversion efficiency, permitting tumor theranostics in a mouse model. SSS-micelles have a wideband absorption in the NIR-II window, allowing for the PA imaging at both 1064 and 1300 nm wavelengths. The PA signal of the SSS-micelles can be detected through 6.5 cm of chicken breast tissue in vitro. In mice or rats, SSS-micelles can be visualized in bladder and intestine overlaid 5 cm (signal to noise ratio, SNR ≈ 17 dB) and 5.8 cm (SNR over 10 dB) chicken breast tissue, respectively. This work demonstrates the SSS-micelles as a nanoplatform for deep tissue theranostics.

RGD-functionalised melanin nanoparticles for intraoperative photoacoustic imaging-guided breast cancer surgery

PURPOSE

Obtaining tumour-free margins is critical for avoiding re-excision and reducing local recurrence following breast-conserving surgery; however, it remains challenging. Imaging-guided surgery provides precise detection of residual lesions and assists surgical resection. Herein, we described water-soluble melanin nanoparticles (MNPs) conjugated with cyclic Arg-Gly-Asp (cRGD) peptides for breast cancer photoacoustic imaging (PAI) and surgical navigation.

METHODS

The cRGD-MNPs were synthesised and characterized for morphology, photoacoustic characteristics and stability. Tumour targeting and toxicity of cRGD-MNPs were determined by using either breast cancer cells, MDA-MB-231 tumour-bearing mice or the FVB/N-Tg (MMTV-PyVT) 634Mul/J mice model. PAI was used to locate the tumour and guide surgical resection in MDA-MB-231 tumour-bearing mice.

RESULTS

The cRGD-MNPs exhibited excellent in vitro and in vivo tumour targeting with low toxicity. Intravenous administration of cRGD-MNPs to MDA-MB-231 tumour-bearing mice showed an approximately 2.1-fold enhancement in photoacoustic (PA) intensity at 2 h, and the ratio of the PA intensity at the tumour site to that in the surrounding normal tissue was 3.2 ± 0.1, which was higher than that using MNPs (1.7 ± 0.3). Similarly, the PA signal in the spontaneous breast cancer increased ~ 2.5-fold at 2 h post-injection of cRGD-MNPs in MMTV-PyVT transgenic mice. Preoperative PAI assessed tumour volume and offered three-dimensional (3D) reconstruction images for accurate surgical planning. Surgical resection following real-time PAI showed high consistency with histopathological analysis.

CONCLUSION

These results highlight that cRGD-MNP-mediated PAI provide a powerful tool for breast cancer imaging and precise tumour resection. cRGD-MNPs with fine PA properties have great potential for clinical translation.

Emerging nanoformulation strategies for phytocompounds and applications from drug delivery to phototherapy to imaging

Over thousands of years, natural bioactive compounds derived from plants (bioactive phytocompounds, BPCs) have been used worldwide to address human health issues. Today, they are a significant resource for drug discovery in the development of modern medicines. Although many BPCs have promising biological activities, most of them cannot be effectively utilized in drugs for therapeutic applications because of their inherent limitations of low solubility, structural instability, short half-life, poor bioavailability, and non-specific distribution to organs. Researchers have utilized emerging nanoformulation (NF) technologies to overcome these limitations as they have demonstrated great potential to improve the solubility, stability, and pharmacokinetic and pharmacodynamic characteristics of BPCs. This review exemplifies NF strategies for resolving the issues associated with BPCs and summarizes recent advances in their preclinical and clinical applications for imaging and therapy. This review also highlights how innovative NF technologies play a leading role in next-generation BPC-based drug development for extended therapeutic applications. Finally, this review discusses the opportunities to take BPCs with meaningful clinical impact from bench to bedside and extend the patent life of BPC-based medicines with new formulations or application to new adjacent diseases beyond the primary drug indications.

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Natural bioactive phytocompounds derived from plants have been used worldwide to address human health issues. However, most of them cannot be effectively utilized in drugs for therapeutic applications because of their inherent limitations.

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Nanoformulation approach has recently been underlined as an emerging pharmaceutical strategy to overcome the intrinsic drawbacks of bioactive phytocompounds.

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Various types of nanoformulation and their up-to-date applications for targeted delivery, phototherapy, and imaging are reviewed. Finally, their clinical implications for the repurposing of bioactive phytocompounds are deliberated.

Multifunctional nanozyme for multimodal imaging-guided enhanced sonodynamic therapy by regulating the tumor microenvironment

Sonodynamic therapy (SDT) is a highly promising approach for cancer therapy, but its efficacy is severely hampered by the low specificity of sonosensitizers and the unfavorable characteristics of the tumor microenvironment (TME), such as hypoxia and glutathione (GSH) overexpression. To solve these problems, in this work, we encapsulated IR780 and MnO₂ in PLGA and linked Angiopep-2 (Ang) to synthesize a multifunctional nanozyme (Ang-IR780-MnO₂-PLGA, AIMP) to enhance SDT. With Ang functionalization to facilitate blood-brain barrier (BBB) penetration and glioma targeting, and through the function of IR780, these nanoparticles (NPs) showed improved targeting of cancer cells, especially mitochondria, and spread deep into tumor centers. Upon low-intensity focused ultrasound (LIFU) irradiation, reactive oxygen species (ROS) were produced and induced tumor cell apoptosis. Combined with the specific mitochondria-targeting ability of IR780, the sonodynamic effects were amplified because mitochondria are sensitive to ROS. In addition, MnO₂ exhibited enzyme-like activity, reacting with the high levels of hydrogen protons (H⁺), H₂O₂ and GSH in the TME to continuously produce oxygen and consume GSH, which further enhanced the effect of SDT. Moreover, Mn²⁺ can be released in response to TME stimulation and used as a magnetic resonance (MR) contrast agent. In addition, IR780 has photoacoustic (PA)/fluorescence (FL) imaging capabilities. Our results demonstrated that AIMP NPs subjected to LIFU triggering maximally enhanced the therapeutic effect of SDT by multiple mechanisms, including multiple targeting, deep penetration, oxygen supply in situ and GSH depletion, thereby significantly inhibiting tumor growth and distal metastasis without systemic toxicity. In summary, this multifunctional nanozyme provides a promising strategy for cancer diagnosis and treatment under the intelligent guidance of multimodal imaging (PA/FL/MR) and may be a safe clinical translational method.

Liposomes as Versatile Platform for Cancer Theranostics: Therapy, Bio-imaging, and Toxicological Aspects

Liposomes are nano-sized formulations having the benefits of site-specificity, biocompatibility, and biodegradability, which make them useful for the therapy and diagnosis of major diseases like cancer. In this review, various synthetic strategies of liposomes and their biomedical application in special concern to cancer are discussed. In context to the biomedical application, this article gives a detailed insight into subcellular targeted therapy and several therapeutic modifications like immunotherapy, receptor-based therapy, phototherapy, and combination therapy. The review also describes the liposome-based imaging platforms and the toxicity associated with liposomes. Owing to a significant amount of benefits of this carrier system, several products have been approved to be launched in the market and several others have already been marketed for clinical use.

131I-Labeled Multifunctional Polyethylenimine/Doxorubicin Complexes with pH-Controlled Cellular Uptake Property for Enhanced SPECT Imaging and Chemo/Radiotherapy of Tumors

Introduction

Smart theranostic nanosystems own a favorable potential to improve internalization within tumor while avoiding nonspecific interaction with normal tissues. However, development of this type of theranostic nanosystems is still a challenge.

Methods

In this study, we developed the iodine-131 (¹³¹I)-labeled multifunctional polyethylenimine (PEI)/doxorubicin (DOX) complexes with pH-controlled cellular uptake property for enhanced single-photon emission computed tomography (SPECT) imaging and chemo/radiotherapy of tumors. Alkoxyphenyl acylsulfonamide (APAS), a typical functional group that could achieve improved cellular uptake of its modified nanoparticles, was utilized to conjugate onto the functional PEI pre-modified with polyethylene glycol (PEG) with terminal groups of monomethyl ether and N-hydroxysuccinimide (mPEG-NHS), PEG with terminal groups of maleimide and succinimidyl valerate (MAL-PEG-SVA) through sulfydryl of APAS and MAL moiety of MAL-PEG-SVA. This was followed by conjugation with 3-(4’-hydroxyphenyl)propionic acid-OSu (HPAO), acetylating leftover amines of PEI, complexing DOX and labeling ¹³¹I to generate the theranostic nanosystems.

Results

The synthesized theranostic nanosystems exhibit favorable water solubility and stability. Every functional PEI can complex approximately 12.4 DOX, which could sustainably release of DOX following a pH-dependent manner. Remarkably, due to the surface modification of APAS, the constructed theranostic nanosystems own the capacity to achieve pH-responsive charge conversion and further lead to improved cellular uptake in cancer cells under slightly acidic condition. Above all, based on the coexistence of DOX and radioactive ¹³¹I in the single nanosystem, the synthesized nanohybrid system could afford enhanced SPECT imaging and chemo/radioactive combination therapy of cancer cells in vitro and xenografted tumor model in vivo.

Discussion

The developed smart nanohybrid system provides a novel strategy to improve the tumor theranostic efficiency and may be applied for different types of cancer.

Recent Progress in Lipid Nanoparticles for Cancer Theranostics: Opportunity and Challenges

Cancer is one of the major leading causes of mortality in the world. The implication of nanotherapeutics in cancer has garnered splendid attention owing to their capability to efficiently address various difficulties associated with conventional drug delivery systems such as non-specific biodistribution, poor efficacy, and the possibility of occurrence of multi-drug resistance. Amongst a plethora of nanocarriers for drugs, this review emphasized lipidic nanocarrier systems for delivering anticancer therapeutics because of their biocompatibility, safety, high drug loading and capability to simultaneously carrying imaging agent and ligands as well. Furthermore, to date, the lack of interaction between diagnosis and treatment has hampered the efforts of the nanotherapeutic approach alone to deal with cancer effectively. Therefore, a novel paradigm with concomitant imaging (with contrasting agents), targeting (with biomarkers), and anticancer agent being delivered in one lipidic nanocarrier system (as cancer theranostics) seems to be very promising in overcoming various hurdles in effective cancer treatment. The major obstacles that are supposed to be addressed by employing lipidic theranostic nanomedicine include nanomedicine reach to tumor cells, drug internalization in cancer cells for therapeutic intervention, off-site drug distribution, and uptake via the host immune system. A comprehensive account of recent research updates in the field of lipidic nanocarrier loaded with therapeutic and diagnostic agents is covered in the present article. Nevertheless, there are notable hurdles in the clinical translation of the lipidic theranostic nanomedicines, which are also highlighted in the present review along with plausible countermeasures.

Biocompatible melanin based theranostic agent for in vivo detection and ablation of orthotopic micro-hepatocellular carcinoma

Early diagnosis and therapy of hepatocellular carcinoma (HCC) is critical to improve the five-year survival rates of patients. Theranostic agents synergized with photothermal ablation are expected to realize the early detection and treatment of orthotopic HCC. However, conventional metallic nanoagents are limited by their potential bio-toxicity to surrounding normal organs. Recently, endogenous biological melanin pigments have been utilized to develop nanoplatforms due to their excellent biocompatibility and degradability. Whereas, the insufficient capability of PEGylated melanin nanoparticles (PEG-MNPs) in photoacoustic (PA) imaging limits their further biomedical applications. Paradoxically, it is difficult to meet these two different requirements. Herein, a multifunctional nanoagent based on melanin (MNPs) conjugating the near-infrared (NIR) dye IR820 was successfully designed and fabricated. Encapsulation by polyethylene glycol (PEG) renders the solubility in water and allows the physical absorption of IR820 for enhanced photoacoustic (PA) performance and photothermal therapy. Besides, PEG coating on the surface of IR820-PEG-MNPs resulted in a reduction in swallowing in the reticuloendothelial system of the liver and spleen, prolonging the circulation time in the blood and increasing the accumulation in the tumor. The IR820-PEG-MNPs displayed satisfactory PA and T1-weighted magnetic resonance imaging (MRI) signals in aqueous solution as well as strong photothermal efficiency. Compared with prior injection, PA/MR signals of the tumor region were enhanced by 4.13- and 1.60-fold, respectively, which could effectively detect lesions smaller than ∼1.8 mm. Furthermore, the high photothermal conversion efficiency (40.2%) endowed the IR820-PEG-MNPs with the capability of selectively ablating tumors in orthotopic HCC mouse models under the guidance of PA/MR imaging. This work broadens the biomedical applications of melanin-based agent, which are promising for the precise diagnosis of orthotopic micro HCC and imaging guided photothermal ablation.

In vivo Multi-scale Photoacoustic Imaging Guided Photothermal Therapy of Cervical Cancer based on Customized Laser System and Targeted Nanoparticles

BACKGROUND

Effective treatment strategy for cervical carcinoma is subject to the limitation of its anatomical location and histological characteristics. Comprehensive imaging before cervical carcinoma treatment is of great significance for the patients. Current imaging methods cannot meet the requirements of high resolution, deep imaging depth and non-invasive imaging at the same time. Fortunately, Photoacoustic imaging (PAI) is a novel imaging method that combines rich optical contrast, high ultrasonic spatial resolution, and deep penetration depth in a single modality. Moreover, PAI-guided photothermal therapy (PTT) by aid of targeting nanoparticles is an emerging and effective cancer treatment in recent years.

METHODS

Here, strong near-infrared region (NIR) absorption-conjugated polymer PIIGDTS (PD) nanoparticles with folic acid (FA) modification (namely, PD-FA) that targeted at Hela cell were specifically designed as cervical tumor imaging contrast agents and photothermal agents.

RESULTS

The obtained PD-FA nanoparticles exhibited admirable photoacoustic contrast-enhancing ability and desirable PTT behavior with the photothermal conversion efficiency as high as 62.6% in vitro. Furthermore, the PAI performance and PTT efficiency were tested in HeLa tumor-bearing nude mice after injection of PD-FA nanoparticles. In vivo multi-scale, PAI provided B-san and 3D dimension imaging for intuitive and comprehensive information of Hela tumor. Moreover, the Hela tumor can be completely eliminated within 18 days after PTT, with no toxicity and side effects.

CONCLUSION

In summary, PD-FA injection combined with PAI and PTT systems provides a novel powerful tool for early diagnosis and precise treatment of cervical cancer.

Magnetic tri-bead microrobot assisted near-infrared triggered combined photothermal and chemotherapy of cancer cells

Magnetic micro/nanorobots attracted much attention in biomedical fields because of their precise movement, manipulation, and targeting abilities. However, there is a lack of research on intelligent micro/nanorobots with stimuli-responsive drug delivery mechanisms for cancer therapy. To address this issue, we developed a type of strong covalently bound tri-bead drug delivery microrobots with NIR photothermal response azobenzene molecules attached to their carboxylic surface groups. The tri-bead microrobots are magnetic and showed good cytocompatibility even when their concentration is up to 200 µg/mL. In vitro photothermal experiments demonstrated fast NIR-responsive photothermal property; the microrobots were heated to 50 °C in 4 min, which triggered a significant increase in drug release. Motion control of the microrobots inside a microchannel demonstrated the feasibility of targeted therapy on tumor cells. Finally, experiments with lung cancer cells demonstrated the effectiveness of targeted chemo-photothermal therapy and were validated by cell viability assays. These results indicated that tri-bead microrobots have excellent potential for targeted chemo-photothermal therapy for lung cancer cell treatment.

Advances in Multiple Stimuli-Responsive Drug-Delivery Systems for Cancer Therapy

Nanomedicines afford unique advantages in therapeutic intervention against tumors. However, conventional nanomedicines have failed to achieve the desired effect against cancers because of the presence of complicated physiological fluids and the tumor microenvironment. Stimuli-responsive drug-delivery systems have emerged as potential tools for advanced treatment of cancers. Versatile nano-carriers co-triggered by multiple stimuli in different levels of organisms (eg, extracorporeal, tumor tissue, cell, subcellular organelles) have aroused widespread interest because they can overcome sequential physiological and pathological barriers to deliver diverse therapeutic “payloads” to the desired targets. Furthermore, multiple stimuli-responsive drug-delivery systems (MSR-DDSs) offer a good platform for co-delivery of agents and reversing multidrug resistance. This review affords a comprehensive overview on the “landscape” of MSR-DDSs against tumors, highlights the design strategies of MSR-DDSs in recent years, discusses the putative advantage of oncotherapy or the obstacles that so far have hindered the clinical translation of MSR-DDSs.

A novel self-coated polydopamine nanoparticle for synergistic photothermal-chemotherapy

The combination of photothermal therapy (PTT) and chemotherapy is a promising strategy to overcome the shortcomings of monotherapy. For the first time, we designed a self-coated nanoparticle formed by mesoporous polydopamine (MPDA) core and polydopamine (PDA) shell, which was used to load docetaxel and modified with hyaluronic acid (HA). The obtained nanoparticle can achieve targeted drug delivery and further exert the synergistic effect of PTT and chemotherapy. The MPDA core has high drug loading due to mesopores, and the PDA shell can prevent the drug from releasing in the non-target-site because of the pH-sensitivity of the PDA. Compared with other PDA coated nanoparticle, self-coated nanoparticle has a simpler composition and can avoid the potential toxicity caused by the introduction of other materials. Experimental results showed that it had good photothermal conversion ability both in vivo and in vitro, and could be actively targeted into tumor cells through HA-mediated targeting. Under laser irradiation, it ablated the tumors. Simple ingredient and preparation, good compatibility and obvious therapeutic effect make it have a broad application prospect in tumor therapy.

Melanins as Sustainable Resources for Advanced Biotechnological Applications

Melanins are a class of biopolymers that are widespread in nature and have diverse origins, chemical compositions, and functions. Their chemical, electrical, optical, and paramagnetic properties offer opportunities for applications in materials science, particularly for medical and technical uses. This review focuses on the application of analytical techniques to study melanins in multidisciplinary contexts with a view to their use as sustainable resources for advanced biotechnological applications, and how these may facilitate the achievement of the United Nations Sustainable Development Goals.

Melanin-loaded CpG DNA hydrogel for modulation of tumor immune microenvironment

Photothermal immunotherapy has emerged as one of the most potent approaches for cancer treatment, but this strategy has suffered from the lack of biodegradability of the photoresponsive materials. In this study, we aimed to develop biodegradable materials for photothermal immunotherapy. To this end, we designed a DNA CpG hydrogel (DH, generated by rolling-circle amplification), loaded it with bis-(3'-5')-cyclic dimeric guanosine monophosphate (G/DH), and coated the formulation with melanin (Mel/G/DH). Mel/G/DH exhibited a temperature increase upon near infrared (NIR) illumination. In vitro, Mel/G/DH plus NIR (808 nm) irradiation, induced the exposure of calreticulin on CT26 cancer cells, and significantly activated the maturation of dendritic cells (DC). In vivo, local administration of Mel/G/DH (+NIR) exerted photothermal killing of primary tumors and induced maturation of DC in lymph nodes. Treatment of primary tumors with Mel/G/DH(+NIR) prevented the growth of rechallenged tumors at a distant site. Survival was 100% in mice treated with Mel/G/DH(+NIR), 5-fold higher than the group treated with Mel/G(+NIR). Mel/G/DH(+NIR) treatment remodeled the immune microenvironment of distant tumors, increasing cytotoxic T cells and decreasing Treg cells. Taken together, the results of this study suggest the potential of Mel/G/DH as a platform for modulating tumor immune microenvironment aimed at preventing the recurrence of distant tumors.

Fluorescent Nanoparticles for Targeted Tumor Imaging and DNA Tracking Gene Delivery In Vitro/In Vivo

Fluorescence detection is desirable to track the gene transfer process in order to explain the mechanism. Here, a fluorescent nanoparticle, diketopyrrolopyrrole-based liposome (DPL), was prepared for DNA delivery and tumor imaging in vitro and in vivo. The process to deliver DNA into cells was detected in real time by DPL according to the fluorescent property. The transfection efficacies (TEs) for luciferase and enhanced green fluorescent protein (EGFP) analysis of DPL were 1.5 times those of the commercial transfection agent Lipo 2000. Importantly, the DPL/DNA system has high EGFP TE in vivo with tumor targeting ability. This work provided an effective strategy for monitoring transfection processes.

Bio-Applications of Multifunctional Melanin Nanoparticles: From Nanomedicine to Nanocosmetics

Bioinspired nanomaterials are ideal components for nanomedicine, by virtue of their expected biocompatibility or even complete lack of toxicity. Natural and artificial melanin-based nanoparticles (MNP), including polydopamine nanoparticles (PDA NP), excel for their extraordinary combination of additional optical, electronic, chemical, photophysical, and photochemical properties. Thanks to these features, melanin plays an important multifunctional role in the design of new platforms for nanomedicine where this material works not only as a mechanical support or scaffold, but as an active component for imaging, even multimodal, and simple or synergistic therapy. The number of examples of bio-applications of MNP increased dramatically in the last decade. Here, we review the most recent ones, focusing on the multiplicity of functions that melanin performs in theranostics platforms with increasing complexity. For the sake of clarity, we start analyzing briefly the main properties of melanin and its derivative as well as main natural sources and synthetic methods, moving to imaging application from mono-modal (fluorescence, photoacoustic, and magnetic resonance) to multi-modal, and then to mono-therapy (drug delivery, anti-oxidant, photothermal, and photodynamic), and finally to theranostics and synergistic therapies, including gene- and immuno- in combination to photothermal and photodynamic. Nanomedicine aims not only at the treatment of diseases, but also to their prevention, and melanin in nature performs a protective action, in the form of nanopigment, against UV-Vis radiations and oxidants. With these functions being at the border between nanomedicine and cosmetics nanotechnology, recently examples of applications of artificial MNP in cosmetics are increasing, paving the road to the birth of the new science of nanocosmetics. In the last part of this review, we summarize and discuss these important recent results that establish evidence of the interconnection between nanomedicine and cosmetics nanotechnology.

Designer nanocarriers for navigating the systemic delivery of oncolytic viruses

Nanotechnology is paving the way for new carrier systems designed to overcome the greatest challenges of oncolytic virotherapy; systemic administration and subsequent implications of immune responses and specific cell binding and entry. Systemic administration of oncolytic agents is vital for disseminated neoplasms, however transition of nanoparticles (NP) to virotherapy has yielded modest results. Their success relies on how they navigate the merry-go-round of often-contradictory phases of NP delivery: circulatory longevity, tissue permeation and cellular interaction, with many studies postulating design features optimal for each phase. This review discusses the optimal design of NPs for the transport of oncolytic viruses within these phases, to determine whether improved virotherapeutic efficacy lies in the pharmacokinetic/pharmacodynamics characteristics of the NP-oncolytic viruses complexes rather than manipulation of the virus and targeting ligands.

Opto-acoustic synergistic irradiation for vaporization of natural melanin-cored nanodroplets at safe energy levels and efficient sono-chemo-photothermal cancer therapy

Rationale: Insufficient penetration and accumulation of theranostic payloads in solid tumors greatly challenge the clinical translation of cancer nanomedicines. To address this challenge, we synthesized natural melanin-cored and doxorubicin-loaded perfluoropentane nanodroplets with good biocompatibility and self-assembling ability. Methods: We used an opto-acoustic synergistic irradiation (OASI) method that was effective at lower energy levels than ultrasound- or laser-only irradiation to safely vaporize the nanodroplets and to cavitate the generated microbubbles for mechanically enhancing intratumoral delivery. The delivered melanin and doxorubicin inside the tumors mediated secondary chemo-photothermal therapy under laser irradiation to fully kill cancer cells. Results: In vivo animal experiments demonstrated direct mechanical disruption of tumor structures (H&E staining), enhanced intratumoral penetration of melanin (photoacoustic imaging), and efficient intratumoral accumulation of doxorubicin (fluorescent imaging). Anti-tumor experiments demonstrated that the nanodroplets combined with OASI treatment and subsequent laser irradiation could efficiently eliminate melanoma tumors. Conclusion: Melanin-cored and doxorubicin-loaded perfluoropentane nanodroplets hold great promise for translational sono-chemo-photothermal cancer therapy.

Iron(II) phthalocyanine Loaded and AS1411 Aptamer Targeting Nanoparticles: A Nanocomplex for Dual Modal Imaging and Photothermal Therapy of Breast Cancer

Purpose

A multi-functional nanoplatform with diagnostic imaging and targeted treatment functions has aroused much interest in the nanomedical research field and has been paid more attention in the field of tumor diagnosis and treatment. However, some existing nano-contrast agents have encountered difficulties in different aspects during clinical promotion, such as complicated preparation process and low specificity. Therefore, it is urgent to find a nanocomplex with good targeting effect, high biocompatibility and significant therapeutic effect for the integration of diagnosis and treatment and clinical transformation.

Materials and Methods

Nanoparticles (NPs) targeting breast cancer were synthesized by phacoemulsification which had liquid fluorocarbon perfluoropentane(PFP) in the core and were loaded with Iron(II) phthalocyanine (FePc) on the shell. The aptamer (APT) AS1411 was outside the shell used as a molecular probe. Basic characterization and targeting abilities of the NPs were tested, and their cytotoxicity and biological safety in vivo were evaluated through CCK-8 assay and blood bio-chemical analysis. The photoacoustic (PA) and ultrasound (US) imaging system were used to assess the effects of AS1411-PLGA@FePc@PFP (A-FP NPs) as dual modal contrast agent in vitro and in vivo. The effects of photothermal therapy (PTT) in vitro and in vivo were evaluated through MCF-7 cells and tumor-bearing nude mouse models.

Results

A-FP NPs, with good stability, great biocompatibility and low toxicity, were of 201.87 ± 1.60 nm in diameter, and have an active targeting effect on breast cancer cells and tissues. With the help of PA/US imaging, it was proved to be an excellent dual modal contrast agent for diagnosis and guidance of targeted therapy. Meanwhile, it can heat up under near-infrared (NIR) laser irradiation and has achieved obvious antitumor effect both in vitro and in vivo experiments.

Conclusion

As a kind of nanomedicine, A-FP NPs can be used in the integration of diagnosis and treatment. The treatment effects and biocompatibility in vivo may provide new thoughts in the clinical transformation of nanomedicine and early diagnosis and treatment of breast cancer.

Hybrid cell membrane-coated nanoparticles: A multifunctional biomimetic platform for cancer diagnosis and therapy

Biomimetic nanotechnology through camouflaging synthetic nanoparticles (NPs) with natural cell membranes, which bestows with immune evasion and superior targeting capacity, has been extensively used in drug delivery systems (DDS) over the last decades. These biomimetic NPs not only retain the physicochemical features of the synthetic vehicles but also inherit the cell membranes' intrinsic functionalities. Combined with these benefits, optimized nano-biomimetic DDS allow maximum delivery efficacy. Compared to erythrocyte/cancer single cell membrane, the hybrid cell membrane expressing CD47 membrane protein and self-recognition molecules, from erythrocytes and cancer cells, provides remarkable features to the synthetic vehicles, such as immune evasion, long-term circulation, and homotypic targeting. In this review, we describe the preparation strategies, the camouflaging mechanism, and the antitumor applications of hybrid cell membrane-camouflaged NPs. Moreover, we discuss further modification of the hybrid cell membrane and the surface properties of fusion cellular membranes. Finally, we summarize the primary challenges and opportunities associated with these NPs. STATEMENT OF SIGNIFICANCE: Camouflaging synthetic nanoparticles with hybrid cell membrane has been extensively highlighted in recent years. The resultant biomimetic nanoparticles not only reserve the physicochemical properties of the synthetic nanoparticles but also inherit the biological functions of source cells. Compared with single cell membrane, hybrid cell membrane can endow synthetic nanoparticles with multiple biofunctions derived from the original source cells. To provide a timely review of this rapidly developing subject of research, this paper summarized recent progress on the hybrid cell membrane-camouflaged nanoparticles as drug delivery systems for cancer diagnosis and treatment. In this review, we focused primarily on five different types of hybrid cell membrane-camouflaged nanoparticles with the preparation strategies, the camouflaging mechanism, and the antitumor applications. Moreover, further modification of the hybrid cell membrane was also discussed for isolating effectively circulating tumor cells.

Tracking Osteoarthritis Progress through Cationic Nanoprobe-Enhanced Photoacoustic Imaging of Cartilage

A major obstacle in osteoarthritis (OA) theranostics is the lack of a timely and accurate monitoring method. It is hypothesized that the loss of anionic glycosaminoglycans (GAGs) in articular cartilage reflects the progression of OA. Thus, this study investigated the feasibility of photoacoustic imaging (PAI) applied for monitoring the in vivo course of OA progression via GAG-targeted cationic nanoprobes. The nanoprobes were synthesized through electrostatic attraction between poly-l-Lysine and melanin (PLL-MNPs). Cartilage explants with different concentrations of GAGs incubated with PLL-MNPs to test the relationship between GAGs content and PA signal intensity. GAG activity was then evaluated in vivo in destabilization of the medial meniscus (DMM) surgically-induced mouse model. To track OA progression over time, mice were imaged consistently for 10 weeks after OA-inducing surgery. X-ray was used to verify the superiority of PAI in detecting OA. The correlation between PAI data and histologic results was also analyzed. In vitro study demonstrated the ability of PLL-MNPs in sensitively detecting different GAGs concentrations. In vivo PAI exhibited significantly lower signal intensity from OA knees compared to normal knees. More importantly, PA signal intensity showed serial reduction over the course of OA, while X-ray showed visible joint destruction until 6 weeks. A decrease in GAGs content was confirmed by histologic examinations; moreover, histologic findings were well correlated with PAI results. Therefore, using cationic nanoprobe-enhanced PAI to detect the changes in GAG contents provides sensitive and consistent visualization of OA development. This approach will further facilitate OA theranostics and clinical translation. STATEMENT OF SIGNIFICANCE: The study of in vivo monitoring osteoarthritis (OA) is of high significance to tracking the trajectory of OA development and therapeutic monitoring. Here, we developed a cartilage-targeted cationic nanoprobe, poly-l-Lysine-melanin nanoparticles (PLL-MNPs), enhancing photoacoustic imaging (PAI) to monitor the progression of OA. The in vitro study demonstrated the ability of PLL-MNPs to detect different concentrations of GAGs with high sensitivity. We found that the contents of GAGs in vivo steadily decreased from the development of OA initial-stage to the end-point of our investigation via PAI; it reflected the course of OA in living subjects with high sensitivity. These results allow for further development in various aspects of OA research. It has potential for clinical translation and has a great impact on personalized medicine.

Melanin-Like Nanomaterials for Advanced Biomedical Applications: A Versatile Platform with Extraordinary Promise

Developing efficient, sustainable, and biocompatible high-tech nanoplatforms derived from naturally existing components in living organisms is highly beneficial for diverse advanced biomedical applications. Melanins are nontoxic natural biopolymers owning widespread distribution in various biosystems, possessing fascinating physicochemical properties and playing significant physiological roles. The multifunctionality together with intrinsic biocompatibility renders bioinspired melanin-like nanomaterials considerably promising as a versatile and powerful nanoplatform with broad bioapplication prospects. This panoramic Review starts with an overview of the fundamental physicochemical properties, preparation methods, and polymerization mechanisms of melanins. A systematical and well-bedded description of recent advancements of melanin-like nanomaterials regarding diverse biomedical applications is then given, mainly focusing on biological imaging, photothermal therapy, drug delivery for tumor treatment, and other emerging biomedicine-related implementations. Finally, current challenges toward clinical translation with an emphasis on innovative design strategies and future striving directions are rationally discussed. This comprehensive and detailed Review provides a deep understanding of the current research status of melanin-like nanomaterials and is expected to motivate further optimization of the design of novel tailorable and marketable multifunctional nanoplatforms in biomedicine.

Tumor pH-responsive metastable-phase manganese sulfide nanotheranostics for traceable hydrogen sulfide gas therapy primed chemodynamic therapy

Manganese-based nanomaterials have piqued great interest in cancer nanotheranostics, owing to their excellent physicochemical properties. Here we report a facile wet-chemical synthesis of size-controllable, biodegradable, and metastable γ-phase manganese sulfide nanotheranostics, which is employed for tumor pH-responsive traceable gas therapy primed chemodynamic therapy (CDT), using bovine serum albumin (BSA) as a biological template (The final product was denoted as MnS@BSA). The as-prepared MnS@BSA can be degraded in response to the mildly acidic tumor microenvironment, releasing hydrogen sulfide (H2S) for gas therapy and manganese ions for magnetic resonance imaging (MRI) and CDT. In vitro experiments validated the pH-responsiveness of MnS@BSA at pH 6.8 and both H2S gas and •OH radicals were detected during its degradation. In vivo experiments showed efficiently tumor turn-on T1-weighted MRI, significantly suppressed tumor growth and greatly prolonged survival of tumor-bearing mice following intravenous administration of MnS@BSA. Our findings indicated that MnS@BSA nanotheranostics hold great potential for traceable H2S gas therapy primed CDT of cancer.