Engineered strategies to enhance tumor penetration of drug-loaded nanoparticles

Targeting lipid metabolism via nanomedicine: A prospective strategy for cancer therapy

Lipid metabolism has been increasingly recognized to play an influencing role in tumor initiation, progression, metastasis, and therapeutic drug resistance. Targeting lipid metabolic reprogramming represents a promising therapeutic strategy. Despite their structural complexity and poor targeting efficacy, lipid-metabolizing drugs, either used alone or in combination with chemotherapeutic agents, have been employed in clinical practice. The advent of nanotechnology offers new approaches to enhancing therapeutic effects, includingthe targeted delivery and integration of lipid metabolic reprogramming with chemotherapy, photodynamic therapy (PDT), and immunotherapy. The integrated nanoformulation, nanomedicine, could significantly advance the field of lipid metabolism therapy. In this review, we will briefly introduce the concept of cancer lipid metabolism reprogramming, then elaborate the latest advances in engineered nanomedicine for targeting lipid metabolism during cancer treatment, and finally provide our insights into future perspectives of nanomedicine for interference with lipid metabolism in the tumor microenvironment.

Cationic Azobenzene Tag to Enhance Liposomal Prodrug Retention and Tumor-Targeting Prodrug Activation for Improved Antitumor Efficacy

In this study, we reported a cationic azobenzene (Azo) tag to increase the retention of camptothecin (CPT) prodrugs in liposomes driven by π-π stacking interaction between Azo. Compared with a cationic CPT prodrug without Azo, the liposome-encapsulating Azo-linked CPT prodrugs (AzoCPT-Lips) exhibited slower prodrug leakage in plasma and a longer blood circulation time in mice. The AzoCPT-Lips had a high encapsulation efficiency (95%), loading capacity (20%, by weight), and good storage stability. The AzoCPT was efficiently taken up by 4T1 tumor cells (100-fold higher than CPT) and readily converted into active CPT in the cytoplasm to exert 10-fold higher cytotoxicity than free CPT. More importantly, AzoCPT-Lips resulted in 5-20 times higher tumor distribution of active CPT than that of CPT solution or those in other tissues, which further led to more potent antitumor activity and lower toxicities in the 4T1 breast cancer xenograft. Such a cationic Azo tag represents an effective strategy for developing liposomal antitumor drugs with improved antitumor efficacy.

Next-Generation Transformable Nanomedicines: Revolutionizing Cancer Drug Delivery and Theranostics

Nanomedicine has significantly advanced the treatment of various cancer phenotypes, addressing numerous challenges associated with conventional therapies. Researchers have extensively investigated the physicochemical properties of nanocarriers, such as charge, morphology, and surface chemistry, to optimize drug delivery systems. In the context of transformable nanomedicine, these properties are particularly critical for overcoming existing limitations, including suboptimal blood circulation times, sequestration by the reticuloendothelial system and mononuclear phagocyte system, and inefficient targeting of the tumor microenvironment (TME). Alterations in nanocarrier geometry, surface charge, and hydrophilicity have shown potential in mitigating these barriers, offering improved therapeutic outcomes and enhanced biomedical applications. This review explores controlled modulation of these properties in the context of anticancer therapy, offering an in-depth exploration of transformable strategies activated by both internal and external stimuli. We analyze the implications of these tunable characteristics on pharmacokinetics, biodistribution, and targeted delivery to the TME. Additionally, we address the current challenges in the clinical translation of these advanced nanocarriers and propose strategies to overcome these obstacles to enhance the clinical feasibility of nanomedicine-based cancer therapies.

Microneedle patch capable of dual drug release for drug delivery to brain tumors

Primary brain tumors are mostly managed using surgical resection procedures. Nevertheless, in certain cases, a thin layer of tumors may remain outside of the resection process due to the possibility of permanent injury; these residual tumors expose patients to the risk of tumor recurrence. This study has introduced the use of microneedle patches implanted after surgery with a dual-release mechanism for the administration of doxorubicin. The proposed patches possess the capability to administer drugs directly to the residual tumors and initiate chemotherapy immediately following surgical procedures. Three-dimensional simulation of drug delivery to residual tumors in the brain has been performed based on a finite element method. The impact of four important parameters on drug delivery has been investigated, involving the fraction of drug released in the burst phase, the density of microneedles on the patch, the length of microneedles, and the microvascular density of the tumor. The simulation findings indicate that lowering the fraction of drug released in the initial burst phase reduces the maximum average concentration, but the sustained release that continues for a longer period, increasing the bioavailability of free drug. However, the area under curve (AUC) for different release rates remains unchanged due to the fact that an identical dose of drug is supplied in each instance. By increasing the density of microneedles on the patch, concentration accumulation is provided over an extensive region of tumor, which in turn induces more cancer cell death. A comparative analysis of various lengths reveals that longer microneedles facilitate profound penetration into the tumor layers and present better therapeutic response due to extensive area of the tumor which is exposure to chemotherapeutic drugs. Furthermore, high microvascular density, as a characteristic of the tumor microenvironment, is shown to have a significant impact on the blood microvessels drainage of drugs and consequently lower therapeutic response outcome. Our approach offers a computational framework for creating localized drug delivery systems and addressing the challenges related to residual brain tumors.

Enhancement and characterization of nanoparticle diffusion in biological tissues by magnetic heating and oscillation

Given the unsatisfactory delivery efficiency of nanoagents to target lesions in biological systems, this study proposed a magnetic field regulation method aimed at boosting nanoparticle (NP) diffusion in porous tissues by leveraging both magneto-thermal effects and magnetic oscillation. In vitro experiments using pork liver tissues and in vivo experiments on fibrosarcoma tumors in mice were conducted. Our study achieved quantitative characterization of NP diffusion, detailing the temporal and spatial distribution of NPs. The results show that the improvement of intratumor NP diffusion driven by an oscillating magnetic field (30 mT, 15 Hz), was notably greater than that due to the magneto-thermal effect from a high-frequency alternating magnetic field (27 kA/m, 115 kHz). Under magnetic oscillation, the overall diffusivity of the NPs in fibrosarcoma tumors was 4.45 times greater than that under untreated conditions. NP diffusivity decreased with increasing diffusion time and length due to the concentration dependence of diffusivity and was strongly influenced by tissue structure.

Inorganic nanoparticles and blood-brain barrier modulation: Advancing targeted neurological therapies

The blood-brain barrier (BBB) is a protective barrier that complicates the treatment of neurological disorders. Pharmaceutical compounds encounter significant challenges in crossing the central nervous system (CNS). Nanoparticles (NPs) are promising candidates for treating neurological conditions as they help facilitate drug delivery. This review explores the diverse characteristics and mechanisms of inorganic NPs (INPs), including metal-based, ferric-oxide, and carbon-based nanoparticles, which facilitate their passage through the BBB. Emphasis is placed on the physicochemical properties of NPs such as size, shape, surface charge, and surface modifications and their role in enhancing drug delivery efficacy, reducing immune clearance, and improving BBB permeability. Specific synthesis approaches are demonstrated, with an emphasis on the influence of each one on NP property, biological activity and the capability of an NP for its intended application. As for the advances in the field, the review emphasizes those characterized the NP formulation and surface chemistry that conquered the BBB and tested the need for its alteration. Current findings indicate that NP therapy can in the future enable effective targeting of specific brain disorders and eventually evolve this drug delivery system, which would allow for lower doses with less side effects.

Fluorescence-Switchable Iron-Doped Nanodot Assembly as a Robust Redox Dyshomeostasis Amplifier for Noninvasive Treatment of Deep-Seated Tumors

Carbon dots (CDs) have been recognized as promising candidates for cancer diagnosis and therapy, owing to their intrinsic fluorescence properties and facile functionalization pathways. However, such tiny-sized CDs tend to be rapidly excreted by the kidney and/or hepatobiliary system before reaching the tumor site, which may significantly weaken their performance in tumor theranostics. Here, fluorescence switchable iron-doped carbon dot assemblies (FCDDs) are developed with an average size of ≈120 nm for passive tumor targeting. After lesional enrichment, FCDDs can be dissembled into Fe-doped CDs (FCDs) with fluorescence switched on, in response to the upregulated glutathione (GSH) in the tumor microenvironment. The ultrasmall FCDs are able to penetrate into the deep region of solid tumors and generate reactive oxygen species (ROS) through the Fenton reaction. Such ROS accumulation and GSH deprivation caused by FCDDs can effectively trigger the irreversible apoptosis and ferroptosis of tumor cells. Meanwhile, the resultant intracellular redox dyshomeostasis induces prominent immunogenic cell death to prevent metastasis. Tumor-specific fluorescence imaging not only enables cancerous tissue probing but also assists in monitoring the treatment effectiveness. Taken together, this paradigm exemplifies a practical approach to improve the functionality of CDs toward clinical applications and may inspire more facile designs toward upcoming translational medicines.

Development of a prediction model for hyperthermia-enhanced drug delivery using thermosensitive nanoparticles

Therapies targeting solid tumors are often hindered by drug resistance mechanisms, which presenting significant challenges. This study investigates the synergistic effect of hyperthermia and chemotherapy by utilizing thermosensitive nanoparticles (NPs) to enhance drug uptake by cancer cells. The thermoresponsive nature of NPs enables precise drug release under hyperthermic conditions, making them ideal for localized treatment. To achieve this, we developed a multi-component numerical model of focused ultrasound-enhanced doxorubicin delivery using tumor-targeting nanoparticles. The model incorporates critical factors such as blood coagulation and non-Fourier heat transfer, and it was validated against experimental results, thereby enhancing the reliability and accuracy of our findings. Ultimately, a prediction model was developed to estimate heat-driven irreversible cell damage in relation to heating power and NP size. The results demonstrated a remarkable 13-fold increase in drug penetration and a 4.6-fold enhancement in the fraction of killed cells with hyperthermia. These findings underscore the importance of accurately controlling the temperature field and heating power for optimal hyperthermia-assisted chemotherapy outcomes.

Mesenchymal stromal cells in bone marrow niche of patients with multiple myeloma: a double-edged sword

Multiple myeloma (MM) is a hematological malignancy defined by the abnormal proliferation and accumulation of plasma cells (PC) within the bone marrow (BM). While multiple myeloma impacts the bone, it is not classified as a primary bone cancer. The bone marrow microenvironment significantly influences the progression of myeloma and its treatment response. Mesenchymal stromal cells (MSCs) in this environment engage with myeloma cells and other bone marrow components via direct contact and the secretion of soluble factors. This review examines the established roles of MSCs in multiple facets of MM pathology, encompassing their pro-inflammatory functions, contributions to tumor epigenetics, effects on immune checkpoint inhibitors (ICIs), influence on reprogramming, chemotherapy resistance, and senescence. This review investigates the role of MSCs in the development and progression of MM.

Tumor microenvironment: recent advances in understanding and its role in modulating cancer therapies

Tumor microenvironment (TME) denotes the non-cancerous cells and components presented in the tumor, including molecules produced and released by them. Interactions between cancer cells, immune cells, stromal cells, and the extracellular matrix within the TME create a dynamic ecosystem that can either promote or hinder tumor growth and spread. The TME plays a pivotal role in either promoting or inhibiting tumor growth and dissemination, making it a critical factor to consider in the development of effective cancer therapies. Understanding the intricate interplay within the TME is crucial for devising effective cancer therapies. Combination therapies involving inhibitors of immune checkpoint blockade (ICB), and/or chemotherapy now offer new approaches for cancer therapy. However, it remains uncertain how to best utilize these strategies in the context of the complex tumor microenvironment. Oncogene-driven changes in tumor cell metabolism can impact the TME to limit immune responses and present barriers to cancer therapy. Cellular and acellular components in tumor microenvironment can reprogram tumor initiation, growth, invasion, metastasis, and response to therapies. Components in the TME can reprogram tumor behavior and influence responses to treatments, facilitating immune evasion, nutrient deprivation, and therapeutic resistance. Moreover, the TME can influence angiogenesis, promoting the formation of blood vessels that sustain tumor growth. Notably, the TME facilitates immune evasion, establishes a nutrient-deprived milieu, and induces therapeutic resistance, hindering treatment efficacy. A paradigm shift from a cancer-centric model to a TME-centric one has revolutionized cancer research and treatment. However, effectively targeting specific cells or pathways within the TME remains a challenge, as the complexity of the TME poses hurdles in designing precise and effective therapies. This review highlights challenges in targeting the tumor microenvironment to achieve therapeutic efficacy; explore new approaches and technologies to better decipher the tumor microenvironment; and discuss strategies to intervene in the tumor microenvironment and maximize therapeutic benefits.

AIEgen-biomacromolecule conjugates: Visualized delivery and light-controlled theranostic platforms

Biomacromolecules play a critical role in advancing disease diagnosis and treatment. Traditional carriers often lack real-time tracking capabilities, controlled drug release, and may induce adverse effects for delivering biomacromolecules. Aggregation-induced emission luminogens (AIEgens) provide significant advantages in biomacromolecule delivery, enabling real-time fluorescence imaging and reactive oxygen species generation for photodynamic therapy (PDT). This dual functionality allows for the visualization of the biomacromolecule delivery process, providing valuable insights into biodistribution, cellular uptake, and drug-cell interactions. Additionally, the light-responsive nature of AIEgens enables precise spatial-temporal control over cargo release and imaging-guided PDT with minimal side effects. In this perspective, we summarize recent advancements in the use of AIEgens for visualized delivery and light-controlled theranostic applications of biomacromolecules, highlighting their potential to overcome challenges in targeted imaging and precision treatments. Key topics covered include covalent linkage strategies and the biomedical applications of AIEgen-functionalized biomacromolecules, including nucleic acids, proteins, polysaccharides, and lipids. We further highlight AIEgen-functionalized gene therapy and PDT for cancer, peptide transport for disease diagnosis, as well as polysaccharides and lipids delivery in antimicrobial treatments. This perspective concludes by addressing future challenges and opportunities, emphasizing the potential of AIEgen-functionalized biomacromolecules to advance precision theranostics.

Advancing neurological disorders therapies: Organic nanoparticles as a key to blood-brain barrier penetration

The blood-brain barrier (BBB) plays a vital role in protecting the central nervous system (CNS) by preventing the entry of harmful pathogens from the bloodstream. However, this barrier also presents a significant obstacle when it comes to delivering drugs for the treatment of neurodegenerative diseases and brain cancer. Recent breakthroughs in nanotechnology have paved the way for the creation of a wide range of nanoparticles (NPs) that can serve as carriers for diagnosis and therapy. Regarding their promising properties, organic NPs have the potential to be used as effective carriers for drug delivery across the BBB based on recent advancements. These remarkable NPs have the ability to penetrate the BBB using various mechanisms. This review offers a comprehensive examination of the intricate structure and distinct properties of the BBB, emphasizing its crucial function in preserving brain balance and regulating the transport of ions and molecules. The disruption of the BBB in conditions such as stroke, Alzheimer's disease, and Parkinson's disease highlights the importance of developing creative approaches for delivering drugs. Through the encapsulation of therapeutic molecules and the precise targeting of transport processes in the brain vasculature, organic NP formulations present a hopeful strategy to improve drug transport across the BBB. We explore the changes in properties of the BBB in various pathological conditions and investigate the factors that affect the successful delivery of organic NPs into the brain. In addition, we explore the most promising delivery systems associated with NPs that have shown positive results in treating neurodegenerative and ischemic disorders. This review opens up new possibilities for nanotechnology-based therapies in cerebral diseases.

Multi-drug sequential release systems: Construction and application for synergistic tumor treatment

In tumor treatment, the sequence and timing of drug action have a large influence on therapeutic efficacy. Multi-drug sequential release systems (MDSRS) enable the sequential and/or on-demand release of multiple drugs following the single administration of a therapeutic agent. Several researchers have explored MDSRS, providing fresh strategies for synergistic cancer therapy. This review article first introduces the main characteristics of MDSRS. It then elaborates on the design principles of MDSRS. Subsequently, it summarizes the various structures of carriers used for constructing MDSRS, including core-shell structure, Layer-by-layer structure, Janus structure and hydrogel. Next, through specific examples, the article emphasizes the application of MDSRS in cancer treatment, focusing on their role in remodeling the tumor microenvironment (TME) and enhancing therapeutic effects through multiple mechanisms. Finally, the article discusses the current limitations and challenges of these systems and proposes potential future solutions. Overall, this review underscores the importance of the sequence and timing of drug therapy in cancer treatment, providing valuable theoretical and technical guidance for pharmaceutical research.

Size-transformable nanotherapeutics for cancer therapy

The size of nanodrugs plays a crucial role in shaping their chemical and physical characteristics, consequently influencing their therapeutic and diagnostic interactions within biological systems. The optimal size of nanomedicines, whether small or large, offers distinct advantages in disease treatment, creating a dilemma in the selection process. Addressing this challenge, size-transformable nanodrugs have surfaced as a promising solution, as they can be tailored to entail the benefits associated with both small and large nanoparticles. In this review, various strategies are summarized for constructing size-transformable nanosystems with a focus on nanotherapeutic applications in the field of biomedicine. Particularly we highlight recent research developments in cancer therapy. This review aims to inspire researchers to further develop various toolboxes for fabricating size-transformable nanomedicines for improved intervention against diverse human diseases.

Aggregation-Caused Quenching Dyes as Potent Tools to Track the Integrity of Antitumor Nanocarriers: A Mini-Review

Cancer has become one of the major causes of death worldwide. Chemotherapy remains a cornerstone of cancer treatment. To enhance the tumor-targeting efficiency of chemotherapy agents, pharmaceutical scientists have developed nanocarriers. However, the in vivo structural integrity and dynamic changes in nanocarriers after administration are not well understood, which may significantly impact their tumor-targeting abilities. In this paper, we propose the use of environmentally responsive fluorescent probes to track the integrity of antitumor nanocarriers. We compare three main types of dyes: fluorescence resonance energy transfer (FRET) dyes, aggregation-induced emission (AIE) dyes, and aggregation-caused quenching (ACQ) dyes. Among them, ACQ dyes, possessing sensitive water-quenching properties and easily detected "on-off" switching behavior, are regarded as the most promising choice. We believe that ACQ dyes are suitable for investigating the in vivo fate of antitumor nanocarriers and can aid in designing improved nanoformulations for chemotherapy agents.

Maytansinoids in cancer therapy: advancements in antibody-drug conjugates and nanotechnology-enhanced drug delivery systems

Cancer remains the second leading cause of death globally, driving the need for innovative therapies. Among natural compounds, maytansinoids have shown significant promise, contributing to nearly 25% of recently approved anticancer drugs. Despite their potential, early clinical trials faced challenges due to severe side effects, prompting advancements in delivery systems such as antibody-maytansinoid conjugates (AMCs). This review highlights the anticancer activity of maytansinoids, with a focus on AMCs designed to target cancer cells specifically. Preclinical and clinical studies show that AMCs, including FDA-approved drugs like Kadcyla and Elahere, effectively inhibit tumor growth while reducing systemic toxicity. Key developments include improved synthesis methods, linker chemistry and payload design. Ongoing research aims to enhance the safety and efficacy of AMCs, integrate nanotechnology for drug delivery, and identify novel therapeutic targets. These advancements hold potential to transform maytansinoid-based cancer treatments in the future.

Cisplatin-functionalized dual-functional bone substitute granules for bone defect treatment after bone tumor resection

Invasive bone tumors pose a significant healthcare challenge, often requiring systemic chemotherapy and limb salvage surgery. However, these strategies are hampered by severe side effects, complex post-resection bone defects, and high local recurrence rates. To address this, we developed dual-functional bone substitute biomaterials by functionalizing commercially available bone substitute granules (Bio-Oss® and MBCP®+) with the established anticancer agent cisplatin. Physicochemical characterization revealed that Bio-Oss® granules possess a higher surface area and lower crystallinity compared to MBCP®+ granules, which enhances their capacity for cisplatin adsorption and release. In co-cultures with metastatic breast and prostate cancer cells (MDA-MB-231 and PC3) and bone marrow stromal cells (hBMSCs), cisplatin-functionalized granules and their releasates exhibited dose-dependent cytotoxic effects on cancer cells while having less impact on hBMSCs. Furthermore, investigations on the mechanism of action indicated that cisplatin induced significant cell cycle arrest and apoptosis in MDA-MB-231 and PC3 cells, contrasting with minimal effects on hBMSCs. In a rat femoral condyle defect model, cisplatin-functionalized granules did not evoke adverse effects on bone tissue ingrowth or new bone formation. Importantly, local application of cisplatin-functionalized granules resulted in negligible cisplatin accumulation without signs of apoptotic damage in kidneys and livers. Taken together, we here provide hard evidence that cisplatin-functionalized granules maintain a favorable balance between biosafety, anticancer efficacy, and bone regenerative capacity. Consequently, loading granular bone substitutes with cisplatin holds promise for local treatment of bone defects following bone tumor resections, presenting a safe and potentially more effective alternative to systemic cisplatin administration. STATEMENT OF SIGNIFICANCE: Current treatments in combating malignant bone tumors are hampered by severe side effects, high local tumor recurrence, and complex bone defects after surgery. This study explores a facile manufacturing method to render two types of commercially available bone substitute granules (Bio-Oss® and MBCP®+) suitable for local delivery of cisplatin. The use of cisplatin-functionalized granules has shown promising results both in killing cancer cells in a dose-dependent manner and in aiding bone regeneration. Importantly, this local treatment strategy avoids the systemic toxicity associated with traditional chemotherapy to excretory organs. This dual-functional strategy represents a significant advancement in bone cancer treatment, offering a safe and more efficient alternative that could improve outcomes for patients following bone tumor resection.

pH-sensitive metal-organic framework carrier decorated with chitosan for controlled drug release

Satisfactory chemotherapeutic efficiency depends on improving the insufficient selectivity of chemotherapeutic drugs and decreasing damages to healthy tissues/cells, hence, the reasonable design and construction of drug carriers are of great significance in tumor treatment. Herein, the pH-sensitive MOF carrier was developed via the decoration of 4-formylphenylboronic acid (4-FPBA) for controlled 5'-deoxy-5-fluorocytidine (DFCR) release with selectivity. Besides, chitosan (CS) was introduced as the "gatekeeper" for the prevention of drug leakage. In vitro tests prove the good biocompatibility of the MOF carrier and desired tumor cells killing efficiency. Notably, the designed drug carrier decorated with CS in our work demonstrates a prospective candidate in tumor microenvironment-triggered DFCR release in tumor therapy.

Mechanobiology of 3D cell confinement and extracellular crowding

Cells and tissues are often under some level of confinement, imposed by the microenvironment and neighboring cells, meaning that there are limitations to cell size, volume changes, and fluid exchanges. 3D cell culture, increasingly used for both single cells and organoids, inherently impose levels of confinement absent in 2D systems. It is thus key to understand how different levels of confinement influences cell survival, cell function, and cell fate. It is well known that the mechanical properties of the microenvironment, such as stiffness and stress relaxation, are important in activating mechanosensitive pathways, and these are responsive to confinement conditions. In this review, we look at how low, intermediate, and high levels of confinement modulate the activation of known mechanobiology pathways, in single cells, organoids, and tumor spheroids, with a specific focus on 3D confinement in microwells, elastic, or viscoelastic scaffolds. In addition, a confining microenvironment can drastically limit cellular communication in both healthy and diseased tissues, due to extracellular crowding. We discuss potential implications of extracellular crowding on molecular transport, extracellular matrix deposition, and fluid transport. Understanding how cells sense and respond to various levels of confinement should inform the design of 3D engineered matrices that recapitulate the physical properties of tissues.

Research Progress on Cyclic-Peptide Functionalized Nanoparticles for Tumor-Penetrating Delivery

A key challenge in cancer treatment is the effective delivery of drugs into deep regions of tumor tissues, which are impermeable due to abnormal vascular network, increased interstitial fluid pressure (IFP), abundant extra cellular matrix (ECM), and heterogeneity of tumor cells. Cyclic peptides have been used for the surface engineering of nanoparticles to enhance the tumor-penetrating efficacy of drugs. Compared with other surface ligands, cyclic peptides are more easily produced by automated chemical synthesis, and they are featured by their higher binding affinity with their targets, tumor selectivity, stability against degradation, and low toxicity. In this review, different types of cyclic peptides, their physicochemical properties and their in vivo pharmacokinetics are introduced. Next, the progress of cyclic peptide-functionalized drug delivery nanodevices is updated, and the mechanism underlying the tumor-penetrating properties of cyclic peptide-functionalized drug delivery nanodevices is discussed.

Enhancing localized chemotherapy with anti-angiogenesis and nanomedicine synergy for improved tumor penetration in well-vascularized tumors

Intratumoral delivery and localized chemotherapy have demonstrated promise in tumor treatment; however, the rapid drainage of therapeutic agents from well-vascularized tumors limits their ability to achieve maximum therapeutic efficacy. Therefore, innovative approaches are needed to enhance treatment efficacy in such tumors. This study utilizes a mathematical modeling platform to assess the efficacy of combination therapy using anti-angiogenic drugs and drug-loaded nanoparticles. Anti-angiogenic drugs are included to reduce blood microvascular density and facilitate drug retention in the extracellular space. In addition, incorporating negatively charged nanoparticles aims to enhance diffusion and distribution of therapeutic agents within well-vascularized tumors. The findings indicate that, in the case of direct injection of free drugs, using compounds with lower drainage rates and higher diffusion coefficients is beneficial for achieving broader diffusion. Otherwise, drugs tend to accumulate primarily around the injection site. For instance, the drug doxorubicin, known for its rapid drainage, requires the prior direct injection of an anti-angiogenic drug with a high diffusion rate to reduce microvascular density and facilitate broader distribution, enhancing penetration depth by 200%. Moreover, the results demonstrate that negatively charged nanoparticles effectively disperse throughout the tissue due to their high diffusion coefficient. In addition, a faster drug release rate from nanoparticles further enhance treatment efficacy, achieving the necessary concentration for complete eradication of tumor compared to slower drug release rates. This study demonstrates the potential of utilizing negatively charged nanoparticles loaded with chemotherapy drugs exhibiting high release rates for localized chemotherapy through intratumoral injection in well-vascularized tumors.

Advancements in photoacoustic imaging for cancer diagnosis and treatment

Photoacoustic imaging provides in vivo morphological and functional information about tumors within surrounding tissue. By integrating ultrasound guidance, this technique enables precise localization and characterization of tumors. Moreover, the introduction of targeted contrast agents has further expanded the capabilities of photoacoustic imaging in the realm of in vivo molecular imaging. These contrast agents facilitate enhanced molecular and cellular characterization of cancer, enabling detailed insights into the disease. This review aims to provide a concise summary of the extensive research conducted in the field of Photoacoustic imaging for cancer management. It encompasses the development of the technology, its applications in clinical settings, and the advancements made in molecular imaging. By consolidating and synthesizing the existing knowledge, this review contributes to a better understanding of the potential of photoacoustic imaging in cancer care. In conclusion, photoacoustic imaging has emerged as a non-ionizing and noninvasive modality with the ability to visualize tissue's optical absorption properties while maintaining ultrasound's spatial resolution. Its integration with targeted contrast agents has enhanced molecular and cellular characterization of cancer. This review serves as a succinct overview of the extensive research conducted in the field, shedding light on the potential of photoacoustic imaging in the management of cancer.

Injectable nanocomposite hydrogel with cascade drug release for treatment of uveal melanoma

Uveal melanoma (UM) is the most common malignant intraocular tumor with the trait of distant metastases. Currently, the standard clinical therapy results in suboptimal outcomes due to ineffective inhibition of tumor metastasis. Thus, developing novel therapeutic modalities for UM remains a critical priority. Herein, we have developed an injectable nanocomposite hydrogel (HA-DOX/LAP gel) through integrating hyaluronic acid-based drug-loaded nanoparticles into an alginate-dopamine gel, delivering the chemotherapeutic drugs, lapatinib and doxorubicin for combinational treatment of UM. HA-DOX/LAP gel is fabricated in situ by a simple injection of the mixed precursor solution into tumor sites and maintains in vivo for more than 21 days. The entrapped drug-loaded nanoparticles can gradually release from HA-DOX/LAP gel, enhancing tumor targeting and penetration, and synchronously releasing lapatinib and doxorubicin into the acidic intracellular environment to synergistically destroy UM cells. In vivo anti-tumor studies conducted in MuM-2B tumor models demonstrated that HA-DOX/LAP gel significantly impedes tumor growth, diminishes postoperative recurrence, and prolongs overall survivals of UM tumor-bearing mice through only single injection. Remarkably, the escaped drug-loaded nanoparticles effectively reduce the risk of tumor metastases. Our findings provide new insights for the development of multifunctional nanocomposite-incorporating combination therapy against UM by targeting tumor recurrence and metastases.

Photobleaching-mediated charge-convertible cyclodextrin nanoparticles achieve deep tumour penetration for rectal cancer theranostics

Although charge-converting nanoparticles (NPs) potentially penetrate tumours deeply, conventional charge conversion strategies possess limitations, including low selectivity and slow, inconsistent conversion rate within the tumour microenvironment. In this study, we synthesized a zwitterionic near-infrared cyclodextrin derivative of heptamethine cyanine and complexed it with pheophorbide-conjugated ferrocene to produce multifunctional theranostic nanotherapeutics. Our NPs demonstrated enhanced tumour-targeting ability, enabling the highly specific imaging of rectal tumours, with tumour-to-rectum signal ratios reaching up to 7.8. The zwitterionic surface charge of the NPs was rapidly converted to a cationic charge within the tumours on 880 nm near-infrared laser irradiation, promoting the tumoural penetration of NPs via transcytosis. After penetration, photodynamic/chemodynamic therapy was initiated using a 660 nm laser. Our NPs eradicated clinically relevant-sized heterotopic tumours (~250 mm3) and orthotopic rectal tumours, displaying their potential as theranostic nanoplatforms for targeting rectal cancer.

Lipid-Based Nanoformulations for Drug Delivery: An Ongoing Perspective

Oils and lipids help make water-insoluble drugs soluble by dispersing them in an aqueous medium with the help of a surfactant and enabling their absorption across the gut barrier. The emergence of microemulsions (thermodynamically stable), nanoemulsions (kinetically stable), and self-emulsifying drug delivery systems added unique characteristics that make them suitable for prolonged storage and controlled release. In the 1990s, solid-phase lipids were introduced to reduce drug leakage from nanoparticles and prolong drug release. Manipulating the structure of emulsions and solid lipid nanoparticles has enabled multifunctional nanoparticles and the loading of therapeutic macromolecules such as proteins, nucleic acid, vaccines, etc. Phospholipids and surfactants with a well-defined polar head and carbon chain have been used to prepare bilayer vesicles known as liposomes and niosomes, respectively. The increasing knowledge of targeting ligands and external factors to gain control over pharmacokinetics and the ever-increasing number of synthetic lipids are expected to make lipid nanoparticles and vesicular systems a preferred choice for the encapsulation and targeted delivery of therapeutic agents. This review discusses different lipids and oil-based nanoparticulate systems for the delivery of water-insoluble drugs. The salient features of each system are highlighted, and special emphasis is given to studies that compare them.

Advances in tumor stroma-based targeted delivery

The tumor stroma plays a crucial role in tumor progression, and the interactions between the extracellular matrix, tumor cells, and stromal cells collectively influence tumor progression and the efficacy of therapeutic agents. Currently, utilizing components of the tumor stroma for drug delivery is a noteworthy strategy. A number of targeted drug delivery systems designed based on tumor stromal components are entering clinical trials. Therefore, this paper provides a thorough examination of the function of tumor stroma in the advancement of targeted drug delivery systems. One approach is to use tumor stromal components for targeted drug delivery, which includes certain stromal components possessing inherent targeting capabilities like HA, laminin, along with targeting stromal cells homologously. Another method entails directly focusing on tumor stromal components to reshape the tumor stroma and facilitate drug delivery. These drug delivery systems exhibit great potential in more effective cancer therapy strategies, such as precise targeting, enhanced penetration, improved safety profile, and biocompatibility. Ultimately, the deployment of these drug delivery systems can deepen our comprehension of tumor stroma and the advanced development of corresponding drug delivery systems.

Disulfide bonds as a molecular switch of enzyme-activatable anticancer drug precise release for fluorescence imaging and enhancing tumor therapy

Enzyme-activatable drug delivery systems have been developed for cancer diagnosis and therapy. However, targeted intracellular drug delivery is a challenge for precisely tumor imaging and therapy due to the increased stability of copolymer nanoparticles (NPs) is accompanied by a notable decrease in enzyme degradation. Herein, disulfide bond was designed as an enzyme-activatable molecular switch of SS-P(G2)2/DOX NPs. The copolymer NPs consists of polyvinylpyrrolidone (PVP) with disulfide bonds in the center and enzyme-degradable peptide dendrites (Phe-Lys) to form dendritic-linear-dendritic triblock copolymers (TBCs). The amphiphilic TBCs could be split into two identical amphiphilic diblock copolymers (DBCs) by glutathione (GSH) in cancer cells specifically while maintaining the same hydrophilic-lipophilic equilibrium. This structural transformation significantly reduced the stability of copolymer NPs and enhanced sensitivity of DOX release by cathepsin B-activated. Subsequently, the released DOX acted as an indicator of fluorescence imaging and chemotherapy drug for cancer cells. The polymeric NPs achieved excellent drug-loaded stability and prolonged blood circulation in vivo, and realized fluorescence imaging and specific cancer cell killing capabilities by responding to the overexpression of GSH and cathepsin B in tumor cells. Furthermore, the copolymer NPs demonstrated excellent blood compatibility and biosafety. Therefore, a novel strategy based on one tumor marker acting as the switch for another tumor microenvironment responsive drug delivery system could be designed for tumor intracellular imaging and chemotherapy.

Polyester nanoparticles delivering chemotherapeutics: Learning from the past and looking to the future to enhance their clinical impact in tumor therapy

Polymeric nanoparticles (NPs), specifically those comprised of biodegradable and biocompatible polyesters, have been heralded as a game-changing drug delivery platform. In fact, poly(α-hydroxy acids) such as polylactide (PLA), poly(lactide-co-glycolide) (PLGA), and poly(ε-caprolactone) (PCL) have been heavily researched in the past three decades as the material basis of polymeric NPs for drug delivery applications. As materials, these polymers have found success in resorbable sutures, biodegradable implants, and even monolithic, biodegradable platforms for sustained release of therapeutics (e.g., proteins and small molecules) and diagnostics. Few fields have gained more attention in drug delivery through polymeric NPs than cancer therapy. However, the clinical translational of polymeric nanomedicines for treating solid tumors has not been congruent with the fervor or funding in this particular field of research. Here, we attempt to provide a comprehensive snapshot of polyester NPs in the context of chemotherapeutic delivery. This includes a preliminary exploration of the polymeric nanomedicine in the cancer research space. We examine the various processes for producing polyester NPs, including methods for surface-functionalization, and related challenges. After a detailed overview of the multiple factors involved with the delivery of NPs to solid tumors, the crosstalk between particle design and interactions with biological systems is discussed. Finally, we report state-of-the-art approaches toward effective delivery of NPs to tumors, aiming at identifying new research areas and re-evaluating the reasons why some research avenues have underdelivered. We hope our effort will contribute to a better understanding of the gap to fill and delineate the future research work needed to bring polyester-based NPs closer to clinical application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Microfluidic systems for modeling digestive cancer: a review of recent progress

Purpose. This review aims to highlight current improvements in microfluidic devices designed for digestive cancer simulation. The review emphasizes the use of multicellular 3D tissue engineering models to understand the complicated biology of the tumor microenvironment (TME) and cancer progression. The purpose is to develop oncology research and improve digestive cancer patients' lives.Methods. This review analyzes recent research on microfluidic devices for mimicking digestive cancer. It uses tissue-engineered microfluidic devices, notably organs on a chip (OOC), to simulate human organ function in the lab. Cell cultivation on modern three-dimensional hydrogel platforms allows precise geometry, biological components, and physiological qualities. The review analyzes novel methodologies, key findings, and technical progress to explain this field's advances.Results. This study discusses current advances in microfluidic devices for mimicking digestive cancer. Micro physiological systems with multicellular 3D tissue engineering models are emphasized. These systems capture complex biochemical gradients, niche variables, and dynamic cell-cell interactions in the tumor microenvironment (TME). These models reveal stomach cancer biology and progression by duplicating the TME. Recent discoveries and technology advances have improved our understanding of gut cancer biology, as shown in the review.Conclusion. Microfluidic systems play a crucial role in modeling digestive cancer and furthering oncology research. These platforms could transform drug development and treatment by revealing the complex biology of the tumor microenvironment and cancer progression. The review provides a complete summary of recent advances and suggests future research for field professionals. The review's major goal is to further medical research and improve digestive cancer patients' lives.

Nanomedicine in Neuroprotection, Neuroregeneration, and Blood-Brain Barrier Modulation: A Narrative Review

Nanomedicine is a newer, promising approach to promote neuroprotection, neuroregeneration, and modulation of the blood-brain barrier. This review includes the integration of various nanomaterials in neurological disorders. In addition, gelatin-based hydrogels, which have huge potential due to biocompatibility, maintenance of porosity, and enhanced neural process outgrowth, are reviewed. Chemical modification of these hydrogels, especially with guanidine moieties, has shown improved neuron viability and underscores tailored biomaterial design in neural applications. This review further discusses strategies to modulate the blood-brain barrier-a factor critically associated with the effective delivery of drugs to the central nervous system. These advances bring supportive solutions to the solving of neurological conditions and innovative therapies for their treatment. Nanomedicine, as applied to neuroscience, presents a significant leap forward in new therapeutic strategies that might help raise the treatment and management of neurological disorders to much better levels. Our aim was to summarize the current state-of-knowledge in this field.

Dendritic polylysine co-delivery of paclitaxel and siAXL enhances the sensitivity of triple-negative breast cancer chemotherapy

Background: Drug resistance is common in triple-negative breast cancer (TNBC) therapy. To identify a method to overcome chemotherapy resistance in TNBC cells, an siRNA targeting the AXL gene (siAXL), which can overcome drug resistance, was used in this study. A nanodelivery system was constructed to co-deliver siAXL and paclitaxel (PTX). Methods: A biodegradable and tumor microenvironment (TME)-sensitive mPEG-coated dendritic polylysine material (PDPLL) was synthesized. This material was used to construct single-molecule nanoparticles to co-deliver PTX and siAXL. The drug encapsulation and morphological properties of the nanoparticles (NPs) were characterized. The sensitivity of the NPs to the TME was evaluated in vitro with a dialysis method. The tumor-targeting effect of the PDPLL NPs was evaluated by fluorescence imaging and drug distribution evaluation in vivo. The ability to overcome drug resistance was evaluated using PTX-resistant 4T1 cells (4T1/PTX cells) in both in vitro and in vivo models. Results: PDPLL NPs had a particle size of 49.6 ± 5.9 nm and a zeta potential of 7.87 ± 0.68 mV. The PTX drug loading (DL)% was 2.59%. The siAXL DL was 2.5 mg PDPLL: 10 nmol siAXL. The release of PTX showed sustained release performance. The release of siAXL showed sensitivity for the TME. The NPs were stable in the plasma. The NPs promoted cell uptake by PTX-resistant 4T1 cells (4T1/PTX) and promoted tumor targeting and permeability in vivo. siAXL enhanced the toxicity and apoptosis efficiency of PTX in 4T1/PTX cells, as well as the cycle arrest efficiency caused by PTX. The NPs improved the above effects. In mouse 4T1/PTX orthotopic tumors, the NPs enhanced the sensitization of PTX to siAXL. Conclusion: The PDPLL NP co-delivery system possesses good encapsulating potential not only for PTX but also for siRNA. It can enhance the tumor-targeting effect and overcome the drug resistance of 4T1/PTX both in vitro and in vivo. This system is a potential delivery system for RNAs.

Plasmonic nanophotothermal therapy: Destruction of 500 mm3 subcutaneous human basal cell carcinoma with gold nanoparticles and near infrared laser

SIGNIFICANCE

Multilesional basal cell carcinoma (BCC) are spread on sun exposed skin areas, including arms, face and back. The first-line treatment remains the surgical resection or Mohs surgery. Despite its high complexity, Mohs surgery is well practiced in USA and Germany and presents very good results both in esthetic and in carcinology point of view. Large lesions more than 2 cm remain challenging to remove by topical cream used in photodynamic therapy (PDT). If these larger lesions are not treated in less than 1 month, they could grow deeply in the skin, thus enhancing the risk of reoccurrence and the severity of the disease. Despite this model herein studied, that is non melanoma skin cancer is a good prognostic cancer, the therapy aims to be applied to more aggressive melanoma skin cancers.

AIM

Total regression of large cutaneous lesions less than 1 month with no reoccurrence.

APPROACH

Tumor induction on murine model bearing a 500 mm3 subcutaneous lesion. Increasing dose of gold nanoparticles at fixed initial concentration C0 = 0.3 mg/mL, infused into the tumor then exposition of the region of interest to NIR medical laser to assess the therapy. One or two intratumoral administration(s) were compared to surgery and control, that is no treatment, laser alone or nanoparticles alone.

RESULTS

Gold nanoparticles alone or the NIR laser alone did not induce the tumor regression. The combination of laser and nanoparticles called plasmonic nanophotothermal therapy induced apoptosis. Derma and hypoderm do not show any visible gold nanoparticles and demonstrated a good cicatrization process.

CONCLUSION

Plasmonic nanophotothermal therapy using two doses of gold nanoparticles was the only protocol that proved its efficacy on large lesions in 14 days, that is 500 mm3 on a murine model bearing human basal cell carcinoma.

Nanotechnology in tissue engineering: expanding possibilities with nanoparticles

Tissue engineering is a multidisciplinary field that merges engineering, material science, and medical biology in order to develop biological alternatives for repairing, replacing, maintaining, or boosting the functionality of tissues and organs. The ultimate goal of tissue engineering is to create biological alternatives for repairing, replacing, maintaining, or enhancing the functionality of tissues and organs. However, the current landscape of tissue engineering techniques presents several challenges, including a lack of suitable biomaterials, inadequate cell proliferation, limited methodologies for replicating desired physiological structures, and the unstable and insufficient production of growth factors, which are essential for facilitating cell communication and the appropriate cellular responses. Despite these challenges, there has been significant progress made in tissue engineering techniques in recent years. Nanoparticles hold a major role within the realm of nanotechnology due to their unique qualities that change with size. These particles, which provide potential solutions to the issues that are met in tissue engineering, have helped propel nanotechnology to its current state of prominence. Despite substantial breakthroughs in the utilization of nanoparticles over the past two decades, the full range of their potential in addressing the difficulties within tissue engineering remains largely untapped. This is due to the fact that these advancements have occurred in relatively isolated pockets. In the realm of tissue engineering, the purpose of this research is to conduct an in-depth investigation of the several ways in which various types of nanoparticles might be put to use. In addition to this, it sheds light on the challenges that need to be conquered in order to unlock the maximum potential of nanotechnology in this area.

Metal-based nanoparticle in cancer treatment: lessons learned and challenges

Cancer, being one of the deadliest diseases, poses significant challenges despite the existence of traditional treatment approaches. This has led to a growing demand for innovative pharmaceutical agents that specifically target cancer cells for effective treatment. In recent years, the use of metal nanoparticles (NPs) as a promising alternative to conventional therapies has gained prominence in cancer research. Metal NPs exhibit unique properties that hold tremendous potential for various applications in cancer treatment. Studies have demonstrated that certain metals possess inherent or acquired anticancer capabilities through their surfaces. These properties make metal NPs an attractive focus for therapeutic development. In this review, we will investigate the applicability of several distinct classes of metal NPs for tumor targeting in cancer treatment. These classes may include gold, silver, iron oxide, and other metals with unique properties that can be exploited for therapeutic purposes. Additionally, we will provide a comprehensive summary of the risk factors associated with the therapeutic application of metal NPs. Understanding and addressing these factors will be crucial for successful clinical translation and to mitigate any potential challenges or failures in the translation of metal NP-based therapies. By exploring the therapeutic potential of metal NPs and identifying the associated risk factors, this review aims to contribute to the advancement of cancer treatment strategies. The anticipated outcome of this review is to provide valuable insights and pave the way for the advancement of effective and targeted therapies utilizing metal NPs specifically for cancer patients.

Impact of the diseased lung microenvironment on the in vivo fate of inhaled particles

Inhalation drug delivery is superior for local lung disease therapy. However, there are several unique absorption barriers for inhaled drugs to overcome, including limited drug deposition at the target site, mucociliary clearance, pulmonary macrophage phagocytosis, and systemic exposure. Moreover, the respiratory disease state can affect or even destroy the physiology of the lung, thus influencing the in vivo fate of inhaled particles compared with that in healthy lungs. Nevertheless, limited information is available on this effect. Thus, in this review, we present pathological changes of the lung microenvironment under varied respiratory diseases and their influence on the in vivo fate of inhaled particles; such insights could provide a basis for rational inhalation particle design based on specific disease states.

Augmentation of the EPR effect by mild hyperthermia to improve nanoparticle delivery to the tumor

The clinical translation of the nanoparticle (NP)-based anticancer therapies is still unsatisfactory due to the heterogeneity of the enhanced permeability and retention (EPR) effect. Despite the promising preclinical outcome of the pharmacological EPR enhancers, their systemic toxicity can limit their clinical application. Hyperthermia (HT) presents an efficient tool to augment the EPR by improving tumor blood flow (TBF) and vascular permeability, lowering interstitial fluid pressure (IFP), and disrupting the structure of the extracellular matrix (ECM). Furthermore, the HT-triggered intravascular release approach can overcome the EPR effect. In contrast to pharmacological approaches, HT is safe and can be focused to cancer tissues. Moreover, HT conveys direct anti-cancer effects, which improve the efficacy of the anti-cancer agents encapsulated in NPs. However, the clinical application of HT is challenging due to the heterogeneous distribution of temperature within the tumor, the length of the treatment and the complexity of monitoring.

Recent research progress on tumour-specific responsive hydrogels

Most existing hydrogels, even recently developed injectable hydrogels that undergo a reversible sol-gel phase transition in response to external stimuli, are designed to gel immediately before or after implantation/injection to prevent the free diffusion of materials and drugs; however, the property of immediate gelation leads to a very weak tumour-targeting ability, limiting their application in anticancer therapy. Therefore, the development of tumour-specific responsive hydrogels for anticancer therapy is imperative because tumour-specific responses improve their tumour-targeting efficacy, increase therapeutic effects, and decrease toxicity and side effects. In this review, we introduce the following three types of tumour-responsive hydrogels: (1) hydrogels that gel specifically at the tumour site; (2) hydrogels that decompose specifically at the tumour site; and (3) hydrogels that react specifically with tumours. For each type, their compositions, the mechanisms of tumour-specific responsiveness and their applications in anticancer treatment are comprehensively discussed.

Near-infrared Light-Triggered Size-Shrinkable theranostic nanomicelles for effective tumor targeting and regression

Most nanomedicines with suitable sizes (normally 100-200 nm) exhibit favorable accumulation in the periphery of tumors but hardly penetrate into deep tumors. Effective penetration of nanomedicines requires smaller sizes (less than 30 nm) to overcome the elevated tumor interstitial fluid pressure. Moreover, integrating an efficient diagnostic agent in the nanomedicines is in high demand for precision theranostics of tumors. To this end, a near-infrared light (NIR) -triggered size-shrinkable micelle system (Fe3O4@AuNFs/DOX-M) coloaded antitumor drug doxorubicin (DOX) and biomodal imaging agent magnetic gold nanoflower (Fe3O4@AuNFs) was developed to achieve efficient theranostic of tumors. Upon the accumulation of Fe3O4@AuNFs/DOX-M in the tumor periphery, a NIR laser was irradiated near the tumor sites, and the loaded Fe3O4@Au NFs could convert the light energy to heat, which triggered the cleavage of DOX-M to the ultra-small micelles (∼5 nm), thus realizing the deep penetration of micelles and on-demand drug release. Moreover, Fe3O4@AuNFs in the micelles could also be used as CT/MRI dual-modal contrast agent to "visualize" the tumor. Up to 92.6 % of tumor inhibition was achieved for the developed Fe3O4@AuNFs/DOX-M under NIR irradiation. This versatile micelle system provided a promising drug carrier platform realizing efficient tumor dual-modal diagnosis and photothermal-chemotherapy integration.

Charge-Switchable nanoparticles to enhance tumor penetration and accumulation

Nanoparticle-based drug delivery systems hold potential in chemotherapy, but their limited accumulation in tumor tissues hinders effective drug concentration for combating tumor growth. Hence, altering the physicochemical properties of nanoparticles, particularly their surface charge, can enhance their performance. This study utilized a computational model to explore a nanoparticle drug delivery system capable of dynamically adjusting its surface charge. In the model, nanoparticles in the bloodstream were assigned a neutral or positive charge, which, upon reaching the tumor microenvironment, switched to a neutral or negative charge, and releasing chemotherapy drugs into the extracellular space. Results revealed that circulating nanoparticles with a positive surface charge, despite having a shorter circulation and high clearance rate compared to their neutral counterparts, could accumulate significantly in the tissue due to their high transvascular rate. After extravasation, neutralized surface-charged nanoparticles tended to accumulate only near blood microvessels due to their low diffusion rate, resulting in substantial released drug drainage back into the bloodstream. On the other hand, nanoparticles with a negative surface charge in the tumor's extracellular space, due to the reduction of nano-bio interactions, were able to penetrate deeper into the tumor, and increasing drug bioavailability by reducing the volume of drained drugs. Furthermore, the analysis suggested that burst drug release yields a higher drug concentration than sustained drug release, however their creation of bioavailability dependent on nanoparticle accumulation in the tissue. The study's findings demonstrate the potential of this delivery system and offer valuable insights for future research in this area.

Bibliometric and visualized analysis of cancer nanomedicine from 2013 to 2023

Cancer nanomedicine has been an emerging field for drug development against malignant tumors during the past three decades. A bibliometric analysis was performed to characterize the current international trends and present visual representations of the evolution and emerging trends in the research and development of nanocarriers for cancer treatment. This study employed bibliometric analysis and visualization techniques to analyze the literature on antitumor nanocarriers published between 2013 and 2023. A total of 98,980 articles on antitumor nanocarriers were retrieved from the Web of Science Core Collection (WoSCC) database and analyzed using the Citespace software for specific characteristics such as publication year, countries/regions, organizations, keywords, and references. Network visualization was constructed by VOSviewer and Citespace. From 2013 to 2023, the annual global publications increased 7.39 times, from 1851 to 13,683. People's Republic of China (2588 publications) was the most productive country. Chinese Academy of Sciences (298 publications) was the most productive organization. The top 5 high-frequency keywords were "nanoparticles," "drug delivery," "nanomedicine," "cancer," and "nanocarriers." The keywords with the strongest citation bursts recently were "cancer immunotherapy," "microenvironment," "antitumor immunity," etc., which indicated the emerging frontiers of antitumor nanomedicine. The co-occurrence cluster analysis of the keywords formed 6 clusters, and most of the top 10 publications by citation counts focused on cluster #1 (nanocarriers) and cluster #2 (cancer immunotherapy). We further provided insightful discussions into the identified subtopics to help researchers gain more details of current trends and hotspots in this field. The present study processes a macro-level literature analysis of antitumor nanocarriers and provides new perspectives and research directions for future development in cancer nanomedicine.

Nano-Engineering Strategies for Tumor-Specific Therapy

Nanodelivery systems (NDSs) provide promising prospects for decreasing drug doses, reducing side effects, and improving therapeutic effects. However, the bioapplications of NDSs are still compromised by their fast clearance, indiscriminate biodistribution, and limited tumor accumulation. Hence, engineering modification of NDSs aiming at promoting tumor-specific therapy and avoiding systemic toxicity is usually needed. An NDS integrating various functionalities, including flexible camouflage, specific biorecognition, and sensitive stimuli-responsiveness, into one sequence would be "smart" and highly effective. Herein, we systematically summarize the related principles, methods, and progress. At the end of the review, we predict the obstacles to precise nanoengineering and prospects for the future application of NDSs.

Development of an ultrasound-mediated nano-sized drug-delivery system for cancer treatment: from theory to experiment

Aim: To establish a methodology for understanding how ultrasound (US) induces drug release from nano-sized drug-delivery systems (NSDDSs) and enhances drug penetration and uptake in tumors. This aims to advance cancer treatment strategies.Materials & methods: We developed a multi-physics mathematical model to elucidate and understand the intricate mechanisms governing drug release, transport and delivery. Unique in vitro models (monolayer, multilayer, spheroid) and a tailored US exposure setup were introduced to evaluate drug penetration and uptake.Results: The results highlight the potential advantages of US-mediated NSDDSs over conventional NSDDSs and chemotherapy, notably in enhancing drug release and inducing cell death.Conclusion: Our sophisticated numerical and experimental methods aid in determining and quantifying drug penetration and uptake into solid tumors.

Enhancing the tumor penetration of multiarm polymers by collagenase modification

Tumor penetration is a critical determinant of the therapy efficacy of nanomedicines. However, the dense extracellular matrix (ECM) in tumors significantly hampers the deep penetration of nanomedicines, resulting in large drug-untouchable areas and unsatisfactory therapy efficacy. Herein, we synthesized a third-generation PAMAM-cored multiarm copolymer and modified the polymer with collagenase to enhance its tumor penetration. Each arm of the copolymer was a diblock copolymer of poly(glutamic acid)-b-poly(carboxybetaine), in which the polyglutamic acid block with abundant side groups was used to link the anticancer agent doxorubicin through the pH-sensitive acylhydrazone linkage, and the zwitterionic poly(carboxybetaine) block provided desired water solubility and anti-biofouling capability. The collagenase was conjugated to the ends of the arms via the thiol-maleimide reaction. We demonstrated that the polymer-bound collagenase could effectively catalyze the degradation of the collagen in the tumor ECM, and consequently augmented the tumor penetration and antitumor efficacy of the drug-loaded polymers.

Niclosamide - encapsulated lipid nanoparticles for the reversal of pulmonary fibrosis

Pulmonary fibrosis (PF) is a serious and progressive fibrotic interstitial lung disease that is possibly life-threatening and that is characterized by fibroblast accumulation and collagen deposition. Nintedanib and pirfenidone are currently the only two FDA-approved oral medicines for PF. Some drugs such as antihelminthic drug niclosamide (Ncl) have shown promising therapeutic potentials for PF treatment. Unfortunately, poor aqueous solubility problems obstruct clinical application of these drugs. Herein, we prepared Ncl-encapsulated lipid nanoparticles (Ncl-Lips) for pulmonary fibrosis therapy. A mouse model of pulmonary fibrosis induced by bleomycin (BLM) was generated to assess the effects of Ncl-Lips and the mechanisms of reversing fibrosis in vivo. Moreover, cell models treated with transforming growth factor β1 (TGFβ1) were used to investigate the mechanism through which Ncl-Lips inhibit fibrosis in vitro. These findings demonstrated that Ncl-Lips could alleviate fibrosis, consequently reversing the changes in the levels of the associated marker. Moreover, the results of the tissue distribution experiment showed that Ncl-Lips had aggregated in the lung. Additionally, Ncl-Lips improved the immune microenvironment in pulmonary fibrosis induced by BLM. Furthermore, Ncl-Lips suppressed the TGFβ1-induced activation of fibroblasts and epithelial-mesenchymal transition (EMT) in epithelial cells. Based on these results, we demonstrated that Ncl-Lips is an efficient strategy for reversing pulmonary fibrosis via drug-delivery.

Skin-derived precursor conditioned medium alleviated photoaging via early activation of TGF-β/Smad signaling pathway by thrombospondin1: In vitro and in vivo studies

Photoaging is one major exogenous factor of skin aging. Efficacy and safety of current anti-photoaging therapies remained to be improved. Our previous studies indicated that skin-derived precursors (SKPs) alleviated photodamage by early activation of TGF-β/Smad signaling pathway via thrombospondin1 (TSP1). However, the research concerning SKP conditioned medium (SKP-CM) has never been reported. In the current study, we aimed to explore the anti-photoaging effects of SKP-CM both in vitro and in vivo, and to elucidate the possible mechanisms. Mouse SKP-CM (mSKP-CM) collection was optimized by a comparative method. The concentration of protein and growth factors in mSKP-CM was detected using BCA protein assay kit and growth factor protein chip. The anti-photoaging effects of mSKP-CM and its regulation of key factors in the TGF-β/Smad signaling pathway were explored using UVA + UVB photoaged mouse fibroblasts (mFBs) and nude mice dorsal skin. The research revealed that mSKP-CM contained significantly higher-concentration of protein and growth factors than mouse mesenchymal stem cell conditioned medium (mDMSC-CM). mSKP-CM alleviated mFBs photoaging by restoring cell viability and relieving senescence and death. ELISA, qRT-PCR, and western blot results implied the potential mechanisms were associated with the early activation of TGF-β/Smad signaling pathway by TSP1. In vivo experiments demonstrated that compared with the topical intradermal mDMSC-CM injection and retinoic acid cream application, the photodamaged mice dorsal skin intradermally injected with mSKP-CM showed significantly better improvement. Consistent with the in vitro results, both western blot and immunohistochemistry results confirmed that protein expression of TSP1, smad2/3, p-smad2/3, TGF-β1, and collagen I increased, and matrix metalloproteinases decreased. In summary, both in vitro and in vivo experiments demonstrated that mSKP-CM alleviated photoaging through an early activation of TGF-β/Smad signaling pathway via TSP1. SKP-CM may serve as a novel and promising cell-free therapeutical approach for anti-photoaging treatment and regenerative medicine.

Effect of biophysical properties of tumor extracellular matrix on intratumoral fate of nanoparticles: Implications on the design of nanomedicine

Nanomedicine has a profound impact on various research domains including drug delivery, diagnostics, theranostics, and regenerative medicine. Nevertheless, the clinical translation of nanomedicines for solid cancer remains limited due to the abundant physiological and pathological barriers in tumor that hinder the intratumoral penetration and distribution of these nanomedicines. In this article, we review the dynamic remodeling of tumor extracellular matrix during the tumor progression, discuss the impact of biophysical obstacles within tumors on the penetration and distribution of nanomedicines within the solid tumor and collect innovative approaches to surmount these obstacles for improving the penetration and accumulation of nanomedicines in tumor. Furthermore, we dissect the challenges and opportunities of the respective approaches, and propose potential avenues for future investigations. The purpose of this review is to provide a perspective guideline on how to effectively enhance the penetration of nanomedicines within tumors using promising methods.

Spatiotemporal modeling of nano-delivered chemotherapeutics for synergistic microwave ablation cancer therapy

BACKGROUND AND OBJECTIVE

The effectiveness of current microwave ablation (MWA) therapies is limited. Administration of thermosensitive liposomes (TSLs) which release drugs in response to heat has presented a significant potential for enhancing the efficacy of thermal ablation treatment, and the benefits of targeted drug delivery. However, a complete knowledge of the mechanobiological processes underlying the drug release process, especially the intravascular drug release mechanism and its distribution in response to MWA needs to be improved. Multiscale computational-based modeling frameworks, integrating different biophysical phenomena, have recently emerged as promising tools to decipher the mechanobiological events in combo therapies. The present study aims to develop a novel multiscale computational model of TSLs delivery following MWA implantation.

METHODS

Due to the complex interplay between the heating procedure and the drug concentration maps, a computational model is developed to determine the intravascular release of doxorubicin from TSL, its transvascular transport into the interstitium, transport in the interstitium, and cell uptake. Computational models can estimate the interplays among liposome and drug properties, tumor perfusion, and heating regimen to examine the impact of essential parameters and to optimize a targeted drug delivery platform.

RESULTS

Results indicated that the synergy of TSLs with MWA allows more localized drug delivery with lower side effects. The drug release rate and tumor permeability play crucial roles in the efficacy of TSLs during MWA treatment. The computational model predicted an unencapsulated drug lime around the ablated zone, which can destroy more cancer cells compared to MWA alone by 40%. Administration of TSLs with a high release rate capacity can improve the percentage of killed cancer cells by 24%. Since the heating duration in MWA is less than 15 min, the presented combination therapy showed better performance for highly permeable tumors.

CONCLUSION

This study highlights the potential of the proposed computational framework to address complex and realistic scenarios in cancer treatment, which can serve as the future research foundation, including advancements in nanomedicine and optimizing the pair of TSL and MWA for both preclinical and clinical studies. The present model could be as a valuable tool for patient-specific calibration of essential parameters.

Self-assembled nanodrug delivery systems for anti-cancer drugs from traditional Chinese medicine

Traditional Chinese medicine (TCM) is a combination of raw herbs and herbal extracts with a plethora of documented beneficial bioactivities, which has unique advantages in anti-tumor therapy, and many of its major bioactive molecules have been identified in recent years due to advances in chemical separation and structural analysis. However, the major chemical classes of plant-derived bioactive compounds frequently possess chemical properties, including poor water solubility, stability, and bioavailability, that limit their therapeutic application. Alternatively, natural small molecules (NSMs) containing these components possess modifiable groups, multiple action sites, hydrophobic side chains, and a rigid skeleton with self-assembly properties that can be exploited to construct self-assembled nanoparticles with therapeutic effects superior to their individual constituents. For instance, the construction of a self-assembled nanodrug delivery system can effectively overcome the strong hydrophobicity and poor in vivo stability of NSMs, thereby greatly improving their bioavailability and enhancing their anti-tumor efficacy. This review summarizes the self-assembly methods, mechanisms, and applications of a variety of NSMs, including terpenoids, flavonoids, alkaloids, polyphenols, and saponins, providing a theoretical basis for the subsequent research on NSMs and the development of SANDDS.

How Precise are Nanomedicines in Overcoming the Blood-Brain Barrier? A Comprehensive Review of the Literature

New nanotechnology strategies for enhancing drug delivery in brain disorders have recently received increasing attention from drug designers. The treatment of neurological conditions, including brain tumors, stroke, Parkinson's Disease (PD), and Alzheimer's disease (AD), may be greatly influenced by nanotechnology. Numerous studies on neurodegeneration have demonstrated the effective application of nanomaterials in the treatment of brain illnesses. Nanocarriers (NCs) have made it easier to deliver drugs precisely to where they are needed. Thus, the most effective use of nanomaterials is in the treatment of various brain diseases, as this amplifies the overall impact of medication and emphasizes the significance of nanotherapeutics through gene therapy, enzyme replacement therapy, and blood-barrier mechanisms. Recent advances in nanotechnology have led to the development of multifunctional nanotherapeutic agents, a promising treatment for brain disorders. This novel method reduces the side effects and improves treatment outcomes. This review critically assesses efficient nano-based systems in light of obstacles and outstanding achievements. Nanocarriers that transfer medications across the blood-brain barrier and nano-assisted therapies, including nano-immunotherapy, nano-gene therapy, nano enzyme replacement therapy, scaffolds, and 3D to 6D printing, have been widely explored for the treatment of brain disorders. This study aimed to evaluate existing literature regarding the use of nanotechnology in the development of drug delivery systems that can penetrate the blood-brain barrier (BBB) and deliver therapeutic agents to treat various brain disorders.

A microthrombus-driven fixed-point cleaved nanosystem for preventing post-thrombolysis recurrence via inhibiting ferroptosis

Thrombus-induced cardiovascular diseases threaten human health. Current treatment strategies often rely on urokinase plasminogen activator (uPA) for its efficacy, yet it has such limiting factors as short half-life, lack of thrombus targeting, and systemic side effects leading to unintended bleeding. In addition, thrombolytic interventions can trigger inflammation-induced damage at thrombus sites, which affects endothelial function. To address these challenges, Fer-1/uPA@pep-CREKA-Lipo (Fu@pep-CLipo) has been developed. This system achieves precise and efficient thrombolysis while enhancing the thrombus microenvironment and mitigating ischemia-reperfusion injury, with exceptional thrombus targeting ability via the strong affinity of the Cys-Arg-Glu-Lys-Ala (CREKA) peptide for fibrin. The Cys-Nle-TPRSFL-DSPE (pep) could respond to the thrombus microenvironment and fixed-point cleavage. The uPA component linked to the liposome surface is strategically cleaved upon exposure to abundant thrombin at thrombus sites. Importantly, the inclusion of Fer-1 within Fu@pep-CLipo contributes to reactive oxygen species (ROS) scavenging and significantly improves the thrombus microenvironment. This innovative approach not only achieves highly efficient and precise thrombolysis but also positively influences the expression of eNOS protein while suppressing inflammatory factors like TNF-α and IL-6. This dual action contributes to improved thrombus inflammatory microenvironment and mitigated ischemia-reperfusion injury.