On-Demand Drug Release from Dual-Targeting Small Nanoparticles Triggered by High-Intensity Focused Ultrasound Enhanced Glioblastoma-Targeting Therapy

Advancements in Targeted Therapies for Colorectal Cancer: Innovative Drug Formulation and Delivery Strategies

Colorectal cancer (CRC) is a leading cause of cancer-related mortality globally, with increasing incidence presenting significant treatment challenges. Traditional nontargeted therapies often result in high toxicity and limited efficacy, underscoring the need for improved treatment modalities. This review highlights recent advancements in drug delivery systems to enhance therapeutic outcomes for CRC. We examine innovative strategies, including computer-assisted pharmaceutical formulation, sustained-release matrices, and prodrugs, as well as targeted delivery mechanisms such as exosomes, liposomes, hydrogels, antibody-drug conjugates, and stimuli-responsive systems. These methodologies offer improved drug biodistribution, enhanced targeting of cancer cells, and reduced off-target effects, promising better clinical outcomes. Additionally, we discuss the development of novel formulations designed to optimize the delivery of therapeutic agents in advanced CRC. Ongoing clinical trials investigating these innovative systems signify a shift toward more effective patient treatment options. While challenges remain in the clinical application of these targeted therapies, continued research offers promising avenues for improving patient outcomes in CRC. This study aims to inform future strategies for managing this aggressive disease, ultimately enhancing survival rates and quality of life for affected individuals.

Application of high intensity focused ultrasound combined with nanomaterials in anti-tumor therapy

High intensity focused ultrasound (HIFU) has demonstrated its safety, efficacy and noninvasiveness in the ablation of solid tumor. However, its further application is limited by its inherent deficiencies, such as postoperative recurrence caused by incomplete ablation and excessive intensity affecting surrounding healthy tissues. Recent research has indicated that the integration of nanomaterials with HIFU exhibits a promising synergistic effect in tumor ablation. The concurrent utilization of nanomaterials with HIFU can help overcome the limitations of HIFU by improving targeting and ablation efficiency, expanding operation area, increasing operation accuracy, enhancing stability and bio-safety during the process. It also provides a platform for multi-therapy and multi-mode imaging guidance. The present review comprehensively expounds upon the synergistic mechanism between nanomaterials and HIFU, summarizes the research progress of nanomaterials as cavitation nuclei and drug carriers in combination with HIFU for tumor ablation. Furthermore, this review highlights the potential for further exploration in the development of novel nanomaterials that enhance the synergistic effect with HIFU on tumor ablation.

Advances in stimuli-responsive gold nanorods for drug-delivery and targeted therapy systems

In recent years, the use of gold nanorods (AuNRs) has garnered considerable attention in biomedical applications due to their unique optical and physicochemical properties. They have been considered as potential tools for the advanced treatment of diseases by various stimuli such as magnetic fields, pH, temperature and light in the fields of targeted therapy, imaging and drug delivery. Their biocompatibility and tunable plasmonic properties make them a versatile platform for a range of biomedical applications. While endogenous stimuli have limited cargo delivery control at specific sites, exogenous stimuli are a more favored approach despite their circumscribed penetration depth for releasing the cargo at the specific target. Dual/multi-stimuli responsive AuNTs can be triggered by multiple stimuli for enhanced control and specificity in biomedical applications. This review provides to provide a summary of the biomedical applications of stimuli-responsive AuNRs, including their endogenous and exogenous properties, as well as their dual/multi-functionality and potential for clinical delivery. This review provides a comprehensive review on the improvement of therapeutic efficacy and the effective control of drug release with AuNRs, highlights AuNRs design strategies in recent years, discusses the advantages or challenges so far in the field of AuNRs. Finally, we have addressed the clinical translation bio-integrated nanoassemblies (CTBNs) in this field.

Stimuli-Responsive Polymeric Nanocarriers Accelerate On-Demand Drug Release to Combat Glioblastoma

Glioblastoma multiforme (GBM) is a highly malignant brain tumor with a poor prognosis and limited treatment options. Drug delivery by stimuli-responsive nanocarriers holds great promise for improving the treatment modalities of GBM. At the beginning of the review, we highlighted the stimuli-active polymeric nanocarriers carrying therapies that potentially boost anti-GBM responses by employing endogenous (pH, redox, hypoxia, enzyme) or exogenous stimuli (light, ultrasonic, magnetic, temperature, radiation) as triggers for controlled drug release mainly via hydrophobic/hydrophilic transition, degradability, ionizability, etc. Modifying these nanocarriers with target ligands further enhanced their capacity to traverse the blood-brain barrier (BBB) and preferentially accumulate in glioma cells. These unique features potentially lead to more effective brain cancer treatment with minimal adverse reactions and superior therapeutic outcomes. Finally, the review summarizes the existing difficulties and future prospects in stimuli-responsive nanocarriers for treating GBM. Overall, this review offers theoretical guidelines for developing intelligent and versatile stimuli-responsive nanocarriers to facilitate precise drug delivery and treatment of GBM in clinical settings.

Doxorubicin-loaded liposome-like particles embedded in chitosan/hyaluronic acid-based hydrogels as a controlled drug release model for local treatment of glioblastoma

Glioblastoma (GBM) resection and medication treatment are limited, and local drug therapies are required. This study aims to create a hybrid system comprising liposome-like particles (LLP-DOX) encapsulated in chitosan/hyaluronic acid/polyethyleneimine (CHI/HA/PEI) hydrogels, enabling controlled local delivery of doxorubicin (DOX) into the resection cavity for treating GBM. CHI/HA/PEI hydrogels were characterized morphologically, physically, chemically, mechanically, and thermally. Findings revealed a high network and compact micro-network structure, along with enhanced physical and thermal stability compared to CHI/HA hydrogels. Simultaneously, drug release from CHI/HA/PEI/LLP-DOX hydrogels was assessed, revealing continuous and controlled release up to the 148th hour, with no significant burst release. Cell studies showed that CHI/HA/PEI hydrogels are biocompatible with low genotoxicity. Additionally, LLP-DOX-loaded CHI/HA/PEI hydrogels significantly decreased cell viability and gene expression levels compared to LLP-DOX alone. It was also observed that the viability of GBM spheroids decreased over time when interacting with CHI/HA/PEI/LLP-DOX hydrogels, accompanied by a reduction in total surface area and an increase in apoptotic tendencies. In this study, we hypothesized that creating a hybrid drug delivery system by encapsulating DOX-loaded LLPs within a CHI/HA/PEI hydrogel matrix could achieve sustained drug release, improve anticancer efficacy via localized treatment, and effectively mitigate GBM progression for 3D microtissues.

Supramolecularly-Cross-Linked Nanogel Assemblies for On-Demand, Ultrasound-Triggered Chemotherapy

Stimulating the release of small nanoparticles (NPs) from a larger NP via the application of an exogenous stimulus offers the potential to address the different size requirements for circulation versus penetration that hinder chemotherapeutic drug delivery. Herein, we report a size-switching nanoassembly-based drug delivery system comprised of ultrasmall starch nanoparticles (SNPs, ∼20-50 nm major size fraction) encapsulated in a poly(oligo(ethylene glycol) methyl ether methacrylate) nanogel (POEGMA, ∼150 nm major size fraction) cross-linked via supramolecular PEG/α-cyclodextrin (α-CD) interactions. Upon heating the nanogel using a non-invasive, high-intensity focused ultrasound (HIFU) trigger, the thermoresponsive POEGMA-CD nanoassemblies are locally de-cross-linked, inducing in situ release of the highly penetrative drug-loaded SNPs. HIFU triggering increased the release of nanoassembly-loaded DOX from 17 to 37% after 3 h, a result correlated with significantly more effective tumor killing relative to nanoassemblies in the absence of HIFU or drug alone. Furthermore, 1.5× more total fluorescence was observed inside a tumor spheroid when nanoassemblies prepared with fluorophore-labeled SNPs were triggered with HIFU relative to the absence of HIFU. We anticipate this strategy holds promise for delivering tunable doses of chemotherapeutic drugs both at and within a tumor site using a non-invasive triggering approach.

Tissue Ablation: Applications and Perspectives

Tissue ablation techniques have emerged as a critical component of modern medical practice and biomedical research, offering versatile solutions for treating various diseases and disorders. Percutaneous ablation is minimally invasive and offers numerous advantages over traditional surgery, such as shorter recovery times, reduced hospital stays, and decreased healthcare costs. Intra-procedural imaging during ablation also allows precise visualization of the treated tissue while minimizing injury to the surrounding normal tissues, reducing the risk of complications. Here, the mechanisms of tissue ablation and innovative energy delivery systems are explored, highlighting recent advancements that have reshaped the landscape of clinical practice. Current clinical challenges related to tissue ablation are also discussed, underlining unmet clinical needs for more advanced material-based approaches to improve the delivery of energy and pharmacology-based therapeutics.

Peptide-Hitchhiking for the Development of Nanosystems in Glioblastoma

Glioblastoma (GBM) remains the epitome of aggressiveness and lethality in the spectrum of brain tumors, primarily due to the blood-brain barrier (BBB) that hinders effective treatment delivery, tumor heterogeneity, and the presence of treatment-resistant stem cells that contribute to tumor recurrence. Nanoparticles (NPs) have been used to overcome these obstacles by attaching targeting ligands to enhance therapeutic efficacy. Among these ligands, peptides stand out due to their ease of synthesis and high selectivity. This article aims to review single and multiligand strategies critically. In addition, it highlights other strategies that integrate the effects of external stimuli, biomimetic approaches, and chemical approaches as nanocatalytic medicine, revealing their significant potential in treating GBM with peptide-functionalized NPs. Alternative routes of parenteral administration, specifically nose-to-brain delivery and local treatment within the resected tumor cavity, are also discussed. Finally, an overview of the significant obstacles and potential strategies to overcome them are discussed to provide a perspective on this promising field of GBM therapy.

High Intensity Focused Ultrasound-Driven Nanomotor for Effective Ferroptosis-Immunotherapy of TNBC

The heterogeneity of triple-negative breast cancers (TNBC) remains challenging for various treatments. Ferroptosis, a recently identified form of cell death resulting from the unrestrained peroxidation of phospholipids, represents a potential vulnerability in TNBC. In this study, a high intensity focused ultrasound (HIFU)-driven nanomotor is developed for effective therapy of TNBC through induction of ferroptosis. Through bioinformatics analysis of typical ferroptosis-associated genes in the FUSCCTNBC dataset, gambogic acid is identified as a promising ferroptosis drug and loaded it into the nanomotor. It is found that the rapid motion of nanomotors propelled by HIFU significantly enhanced tumor accumulation and penetration. More importantly, HIFU not only actuated nanomotors to trigger effective ferroptosis of TNBC cells, but also drove nanomotors to activate ferroptosis-mediated antitumor immunity in primary and metastatic TNBC models, resulting in effective tumor regression and prevention of metastases. Overall, HIFU-driven nanomotors show great potential for ferroptosis-immunotherapy of TNBC.

Nanoreactor-based catalytic systems for therapeutic applications: Principles, strategies, and challenges

Inspired by natural catalytic compartments, various synthetic compartments that seclude catalytic reactions have been developed to understand complex multistep biosynthetic pathways, bestow therapeutic effects, or extend biosynthetic pathways in living cells. These emerging nanoreactors possessed many advantages over conventional biomedicine, such as good catalytic activity, specificity, and sustainability. In the past decade, a great number of efficient catalytic systems based on diverse nanoreactors (polymer vesicles, liposome, polymer micelles, inorganic-organic hybrid materials, MOFs, etc.) have been designed and employed to initiate in situ catalyzed chemical reactions for therapy. This review aims to present the recent progress in the development of catalytic systems based on nanoreactors for therapeutic applications, with a special emphasis on the principles and design strategies. Besides, the key components of nanoreactor-based catalytic systems, including nanocarriers, triggers or energy inputs, and products, are respectively introduced and discussed in detail. Challenges and prospects in the fabrication of therapeutic catalytic nanoreactors are also discussed as a conclusion to this review. We believe that catalytic nanoreactors will play an increasingly important role in modern biomedicine, with improved therapeutic performance and minimal side effects.

Recent Advances in Antimicrobial Peptide Hydrogels

Advances in the number and type of available biomaterials have improved medical devices such as catheters, stents, pacemakers, prosthetic joints, and orthopedic devices. The introduction of a foreign material into the body comes with a risk of microbial colonization and subsequent infection. Infections of surgically implanted devices often lead to device failure, which leads to increased patient morbidity and mortality. The overuse and improper use of antimicrobials has led to an alarming rise and spread of drug-resistant infections. To overcome the problem of drug-resistant infections, novel antimicrobial biomaterials are increasingly being researched and developed. Hydrogels are a class of 3D biomaterials consisting of a hydrated polymer network with tunable functionality. As hydrogels are customizable, many different antimicrobial agents, such as inorganic molecules, metals, and antibiotics have been incorporated or tethered to them. Due to the increased prevalence of antibiotic resistance, antimicrobial peptides (AMPs) are being increasingly explored as alternative agents. AMP-tethered hydrogels are being increasingly examined for antimicrobial properties and practical applications, such as wound-healing. Here, we provide a recent update, from the last 5 years of innovations and discoveries made in the development of photopolymerizable, self-assembling, and AMP-releasing hydrogels.

Mechanisms of Resistance and Current Treatment Options for Glioblastoma Multiforme (GBM)

Glioblastoma multiforme (GBM) is a highly aggressive form of brain cancer that is difficult to treat due to its resistance to both radiation and chemotherapy. This resistance is largely due to the unique biology of GBM cells, which can evade the effects of conventional treatments through mechanisms such as increased resistance to cell death and rapid regeneration of cancerous cells. Additionally, the blood–brain barrier makes it difficult for chemotherapy drugs to reach GBM cells, leading to reduced effectiveness. Despite these challenges, there are several treatment options available for GBM. The standard of care for newly diagnosed GBM patients involves surgical resection followed by concurrent chemoradiotherapy and adjuvant chemotherapy. Emerging treatments include immunotherapy, such as checkpoint inhibitors, and targeted therapies, such as bevacizumab, that attempt to attack specific vulnerabilities in GBM cells. Another promising approach is the use of tumor-treating fields, a type of electric field therapy that has been shown to slow the growth of GBM cells. Clinical trials are ongoing to evaluate the safety and efficacy of these and other innovative treatments for GBM, intending to improve with outcomes for patients.

Metal-Organic Frameworks (MOF)-Assisted Sonodynamic Therapy in Anticancer Applications

Sonodynamic therapy (SDT) has emerged as a promising therapeutic modality for anticancer treatments and is becoming a cutting-edge interdisciplinary research field. This review starts with the latest developments of SDT and provides a brief comprehensive discussion on ultrasonic cavitation, sonodynamic effect, and sonosensitizers in order to popularize the basic principles and probable mechanisms of SDT. Then the recent progress of MOF-based sonosensitizers is overviewed, and the preparation methods and properties (e.g., morphology, structure, and size) of products are presented in a fundamental perspective. More importantly, many deep observations and understanding toward MOF-assisted SDT strategies were described in anticancer applications, aiming to highlight the advantages and improvements of MOF-augmented SDT and synergistic therapies. Last but not least, the review also pointed out the probable challenges and technological potential of MOF-assisted SDT for the future advance. In all, the discussions and summaries of MOF-based sonosensitizers and SDT strategies will promote the fast development of anticancer nanodrugs and biotechnologies.

Recent Advances in Targeted Nanocarriers for the Management of Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a life-threatening form of breast cancer which has been found to account for 15% of all the subtypes of breast cancer. Currently available treatments are significantly less effective in TNBC management because of several factors such as poor bioavailability, low specificity, multidrug resistance, poor cellular uptake, and unwanted side effects being the major ones. As a rapidly growing field, nano-therapeutics offers promising alternatives for breast cancer treatment. This platform provides a suitable pathway for crossing biological barriers and allowing sustained systemic circulation time and an improved pharmacokinetic profile of the drug. Apart from this, it also provides an optimized target-specific drug delivery system and improves drug accumulation in tumor cells. This review provides insights into the molecular mechanisms associated with the pathogenesis of TNBC, along with summarizing the conventional therapy and recent advances of different nano-carriers for the management of TNBC.

"Smart" drug delivery: A window to future of translational medicine

Chemotherapy is the mainstay of cancer treatment today. Chemotherapeutic drugs are non-selective and can harm both cancer and healthy cells, causing a variety of adverse effects such as lack of specificity, cytotoxicity, short half-life, poor solubility, multidrug resistance, and acquiring cancer stem-like characteristics. There is a paradigm shift in drug delivery systems (DDS) with the advent of smarter ways of targeted cancer treatment. Smart Drug Delivery Systems (SDDSs) are stimuli responsive and can be modified in chemical structure in response to light, pH, redox, magnetic fields, and enzyme degradation can be future of translational medicine. Therefore, SDDSs have the potential to be used as a viable cancer treatment alternative to traditional chemotherapy. This review focuses mostly on stimuli responsive drug delivery, inorganic nanocarriers (Carbon nanotubes, gold nanoparticles, Meso-porous silica nanoparticles, quantum dots etc.), organic nanocarriers (Dendrimers, liposomes, micelles), antibody-drug conjugates (ADC) and small molecule drug conjugates (SMDC) based SDDSs for targeted cancer therapy and strategies of targeted drug delivery systems in cancer cells.

Focused ultrasound-mediated small-molecule delivery to potentiate immune checkpoint blockade in solid tumors

In the last decade, immune checkpoint blockade (ICB) has revolutionized the standard of treatment for solid tumors. Despite success in several immunogenic tumor types evidenced by improved survival, ICB remains largely unresponsive, especially in "cold tumors" with poor lymphocyte infiltration. In addition, side effects such as immune-related adverse events (irAEs) are also obstacles for the clinical translation of ICB. Recent studies have shown that focused ultrasound (FUS), a non-invasive technology proven to be effective and safe for tumor treatment in clinical settings, could boost the therapeutic effect of ICB while alleviating the potential side effects. Most importantly, the application of FUS to ultrasound-sensitive small particles, such as microbubbles (MBs) or nanoparticles (NPs), allows for precise delivery and release of genetic materials, catalysts and chemotherapeutic agents to tumor sites, thus enhancing the anti-tumor effects of ICB while minimizing toxicity. In this review, we provide an updated overview of the progress made in recent years concerning ICB therapy assisted by FUS-controlled small-molecule delivery systems. We highlight the value of different FUS-augmented small-molecules delivery systems to ICB and describe the synergetic effects and underlying mechanisms of these combination strategies. Furthermore, we discuss the limitations of the current strategies and the possible ways that FUS-mediated small-molecule delivery systems could boost novel personalized ICB treatments for solid tumors.

All-stage targeted therapy for the brain metastasis from triple-negative breast cancer

Brain metastasis is a common and serious complication of breast cancer, which is commonly associated with poor survival and prognosis. In particular, the treatment of brain metastasis from triple-negative breast cancer (BM-TNBC) has to face the distinct therapeutic challenges from tumor heterogeneity, circulating tumor cells (CTCs), blood-brain barrier (BBB) and blood-tumor barrier (BTB), which is in unmet clinical needs. Herein, combining with the advantages of synthetic and natural targeting moieties, we develop a "Y-shaped" peptide pVAP-decorated platelet-hybrid liposome drug delivery system to address the all-stage targeted drug delivery for the whole progression of BM-TNBC. Inherited from the activated platelet, the hybrid liposomes still retain the native affinity toward CTCs. Further, the peptide-mediated targeting to breast cancer cells and transport across BBB/BTB are demonstrated in vitro and in vivo. The resultant delivery platform significantly improves the drug accumulation both in orthotopic breast tumors and brain metastatic lesions, and eventually exhibits an outperformance in the inhibition of BM-TNBC compared with the free drug. Overall, this work provides a promising prospect for the comprehensive treatment of BM-TNBC, which could be generalized to other cell types or used in imaging platforms in the future.

Recent Advances in Stimuli-Responsive Doxorubicin Delivery Systems for Liver Cancer Therapy

Doxorubicin (DOX) is one of the most commonly used drugs in liver cancer. Unfortunately, the traditional chemotherapy with DOX presents many limitations, such as a systematic release of DOX, affecting both tumor tissue and healthy tissue, leading to the apparition of many side effects, multidrug resistance (MDR), and poor water solubility. Furthermore, drug delivery systems' responsiveness has been intensively studied according to the influence of different internal and external stimuli on the efficiency of therapeutic drugs. In this review, we discuss both internal stimuli-responsive drug-delivery systems, such as redox, pH and temperature variation, and external stimuli-responsive drug-delivery systems, such as the application of magnetic, photo-thermal, and electrical stimuli, for the controlled release of Doxorubicin in liver cancer therapy, along with the future perspectives of these smart delivery systems in liver cancer therapy.

Peptides as Pharmacological Carriers to the Brain: Promises, Shortcomings and Challenges

Central nervous system (CNS) diseases are among the most difficult to treat, mainly because the vast majority of the drugs fail to cross the blood-brain barrier (BBB) or to reach the brain at concentrations adequate to exert a pharmacological activity. The obstacle posed by the BBB has led to the in-depth study of strategies allowing the brain delivery of CNS-active drugs. Among the most promising strategies is the use of peptides addressed to the BBB. Peptides are versatile molecules that can be used to decorate nanoparticles or can be conjugated to drugs, with either a stable link or as pro-drugs. They have been used to deliver to the brain both small molecules and proteins, with applications in diverse therapeutic areas such as brain cancers, neurodegenerative diseases and imaging. Peptides can be generally classified as receptor-targeted, recognizing membrane proteins expressed by the BBB microvessels (e.g., Angiopep2, CDX, and iRGD), "cell-penetrating peptides" (CPPs; e.g. TAT_47-57, SynB1/3, and Penetratin), undergoing transcytosis through unspecific mechanisms, or those exploiting a mixed approach. The advantages of peptides have been extensively pointed out, but so far few studies have focused on the potential negative aspects. Indeed, despite having a generally good safety profile, some peptide conjugates may display toxicological characteristics distinct from those of the peptide itself, causing for instance antigenicity, cardiovascular alterations or hemolysis. Other shortcomings are the often brief lifetime in vivo, caused by the presence of peptidases, the vulnerability to endosomal/lysosomal degradation, and the frequently still insufficient attainable increase of brain drug levels, which remain below the therapeutically useful concentrations. The aim of this review is to analyze not only the successful and promising aspects of the use of peptides in brain targeting but also the problems posed by this strategy for drug delivery.

Functional Nanoparticles for Enhanced Cancer Therapy

Cancer is the leading cause of death in people worldwide. The conventional therapeutic approach is mainly based on chemotherapy, which has a series of side effects. Compared with traditional chemotherapy drugs, nanoparticle-based delivery of anti-cancer drugs possesses a few attractive features. The application of nanotechnology in an interdisciplinary manner in the biomedical field has led to functional nanoparticles achieving much progress in cancer therapy. Nanoparticles have been involved in the diagnosis and targeted and personalized treatment of cancer. For example, different nano-drug strategies, including endogenous and exogenous stimuli-responsive, surface conjugation, and macromolecular encapsulation for nano-drug systems, have successfully prevented tumor procession. The future for functional nanoparticles is bright and promising due to the fast development of nanotechnology. However, there are still some challenges and limitations that need to be considered. Based on the above contents, the present article analyzes the progress in developing functional nanoparticles in cancer therapy. Research gaps and promising strategies for the clinical application are discussed.

Perfluorocarbon Nanodroplets as Potential Nanocarriers for Brain Delivery Assisted by Focused Ultrasound-Mediated Blood–Brain Barrier Disruption

The management of brain diseases remains a challenge, particularly because of the difficulty for drugs to cross the blood–brain barrier. Among strategies developed to improve drug delivery, nano-sized emulsions (i.e., nanoemulsions), employed as nanocarriers, have been described. Moreover, focused ultrasound-mediated blood–brain barrier disruption using microbubbles is an attractive method to overcome this barrier, showing promising results in clinical trials. Therefore, nanoemulsions combined with this technology represent a real opportunity to bypass the constraints imposed by the blood–brain barrier and improve the treatment of brain diseases. In this work, a stable freeze-dried emulsion of perfluorooctyl bromide nanodroplets stabilized with home-made fluorinated surfactants able to carry hydrophobic agents is developed. This formulation is biocompatible and droplets composing the emulsion are internalized in multiple cell lines. After intravenous administration in mice, droplets are eliminated from the bloodstream in 24 h (blood half-life (t_1/2) = 3.11 h) and no long-term toxicity is expected since they are completely excreted from mice’ bodies after 72 h. In addition, intracerebral accumulation of tagged droplets is safely and significantly increased after focused ultrasound-mediated blood–brain barrier disruption. Thus, the proposed nanoemulsion appears as a promising nanocarrier for a successful focused ultrasound-mediated brain delivery of hydrophobic agents.

An update on dual targeting strategy for cancer treatment

The key issue in the treatment of solid tumors is the lack of efficient strategies for the targeted delivery and accumulation of therapeutic cargoes in the tumor microenvironment (TME). Targeting approaches are designed for more efficient delivery of therapeutic agents to cancer cells while minimizing drug toxicity to normal cells and off-targeting effects, while maximizing the eradication of cancer cells. The highly complicated interrelationship between the physicochemical properties of nanoparticles, and the physiological and pathological barriers that are required to cross, dictates the need for the success of targeting strategies. Dual targeting is an approach that uses both purely biological strategies and physicochemical responsive smart delivery strategies to increase the accumulation of nanoparticles within the TME and improve targeting efficiency towards cancer cells. In both approaches, either one single ligand is used for targeting a single receptor on different cells, or two different ligands for targeting two different receptors on the same or different cells. Smart delivery strategies are able to respond to triggers that are typical of specific disease sites, such as pH, certain specific enzymes, or redox conditions. These strategies are expected to lead to more precise targeting and better accumulation of nano-therapeutics. This review describes the classification and principles of dual targeting approaches and critically reviews the efficiency of dual targeting strategies, and the rationale behind the choice of ligands. We focus on new approaches for smart drug delivery in which synthetic and/or biological moieties are attached to nanoparticles by TME-specific responsive linkers and advanced camouflaged nanoparticles.

Stimuli-Responsive Gold Nanocages for Cancer Diagnosis and Treatment

With advances in nanotechnology, various new drug delivery systems (DDSs) have emerged and played a key role in the diagnosis and treatment of cancers. Over the last two decades, gold nanocages (AuNCs) have been attracting considerable attention because of their outstanding properties. This review summarizes current advancements in endogenous, exogenous, and dual/multi-stimuli responsive AuNCs in drug delivery. This review focuses on the properties, clinical translation potential, and limitations of stimuli-responsive AuNCs for cancer diagnosis and treatment.

Combinatorial therapeutic strategies for enhanced delivery of therapeutics to brain cancer cells through nanocarriers: current trends and future perspectives

Brain cancer is the most aggressive one among various cancers. It has a drastic impact on people's lives because of the failure in treatment efficacy of the currently employed strategies. Various strategies used to relieve pain in brain cancer patients and to prolong survival time include radiotherapy, chemotherapy, and surgery. Nevertheless, several inevitable limitations are accompanied by such treatments due to unsatisfactory curative effects. Generally, the treatment of cancers is very challenging due to many reasons including drugs’ intrinsic factors and physiological barriers. Blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB) are the two additional hurdles in the way of therapeutic agents to brain tumors delivery. Combinatorial and targeted therapies specifically in cancer show a very promising role where nanocarriers’ based formulations are designed primarily to achieve tumor-specific drug release. A dual-targeting strategy is a versatile way of chemotherapeutics delivery to brain tumors that gets the aid of combined ligands and mediators that cross the BBB and reaches the target site efficiently. In contrast to single targeting where one receptor or mediator is targeted, the dual-targeting strategy is expected to produce a multiple-fold increase in therapeutic efficacy for cancer therapy, especially in brain tumors. In a nutshell, a dual-targeting strategy for brain tumors enhances the delivery efficiency of chemotherapeutic agents via penetration across the blood-brain barrier and enhances the targeting of tumor cells. This review article highlights the ongoing status of the brain tumor therapy enhanced by nanoparticle based delivery with the aid of dual-targeting strategies. The future perspectives in this regard have also been highlighted.

In vivo self-assembled drug nanocrystals for metastatic breast cancer all-stage targeted therapy

Chemotherapy is still the mainstay treatment for metastatic triple-negative breast cancers (TNBC) currently in clinical practice. The unmet needs of chemotherapy for metastatic TNBC are mainly from the insufficient drug delivery and unavailable targeting strategy that thwart the whole progression of metastatic TNBC. The in vivo ligands-mediated active targeting efficiency is usually affected by protein corona. While, the protein corona-bridged natural targeting, in turn, provides a new way for specific drug delivery. Herein, we develop a novel metastatic progression-oriented in vivo self-assembled Cabazitaxel nanocrystals (CNC) delivery system (PC/CNC) through the CNC automatically absorbing functional plasma proteins (transferrin, apolipoprotein A-IV and apolipoprotein E) in vivo, aiming to achieve the simultaneously targeted delivery to primary tumors, circulating tumor cells and metastatic lesions. With the unique advantages of superhigh drug-loading and protein corona empowered active targeting properties to tumor cells, HUVECs, active-platelets and blood-brain barrier/blood-tumor barrier, the PC/CNC exhibits a significantly improved therapeutic effect in metastatic TNBC therapy compared with free drug and CNC-loaded liposomes.

Progress and Viewpoints of Multifunctional Composite Nanomaterials for Glioblastoma Theranostics

The most common malignant tumor of the brain is glioblastoma multiforme (GBM) in adults. Many patients die shortly after diagnosis, and only 6% of patients survive more than 5 years. Moreover, the current average survival of malignant brain tumors is only about 15 months, and the recurrence rate within 2 years is almost 100%. Brain diseases are complicated to treat. The reason for this is that drugs are challenging to deliver to the brain because there is a blood–brain barrier (BBB) protection mechanism in the brain, which only allows water, oxygen, and blood sugar to enter the brain through blood vessels. Other chemicals cannot enter the brain due to their large size or are considered harmful substances. As a result, the efficacy of drugs for treating brain diseases is only about 30%, which cannot satisfy treatment expectations. Therefore, researchers have designed many types of nanoparticles and nanocomposites to fight against the most common malignant tumors in the brain, and they have been successful in animal experiments. This review will discuss the application of various nanocomposites in diagnosing and treating GBM. The topics include (1) the efficient and long-term tracking of brain images (magnetic resonance imaging, MRI, and near-infrared light (NIR)); (2) breaking through BBB for drug delivery; and (3) natural and chemical drugs equipped with nanomaterials. These multifunctional nanoparticles can overcome current difficulties and achieve progressive GBM treatment and diagnosis results.

Angiopep-2-Modified Nanoparticles for Brain-Directed Delivery of Therapeutics: A Review

Nanotechnology has opened up a world of possibilities for the treatment of brain disorders. Nanosystems can be designed to encapsulate, carry, and deliver a variety of therapeutic agents, including drugs and nucleic acids. Nanoparticles may also be formulated to contain photosensitizers or, on their own, serve as photothermal conversion agents for phototherapy. Furthermore, nano-delivery agents can enhance the efficacy of contrast agents for improved brain imaging and diagnostics. However, effective nano-delivery to the brain is seriously hampered by the formidable blood-brain barrier (BBB). Advances in understanding natural transport routes across the BBB have led to receptor-mediated transcytosis being exploited as a possible means of nanoparticle uptake. In this regard, the oligopeptide Angiopep-2, which has high BBB transcytosis capacity, has been utilized as a targeting ligand. Various organic and inorganic nanostructures have been functionalized with Angiopep-2 to direct therapeutic and diagnostic agents to the brain. Not only have these shown great promise in the treatment and diagnosis of brain cancer but they have also been investigated for the treatment of brain injury, stroke, epilepsy, Parkinson's disease, and Alzheimer's disease. This review focuses on studies conducted from 2010 to 2021 with Angiopep-2-modified nanoparticles aimed at the treatment and diagnosis of brain disorders.

Perfluorooctyl bromide nanoemulsions holding MnO2 nanoparticles with dual-modality imaging and glutathione depletion enhanced HIFU-eliciting tumor immunogenic cell death

Tumor-targeted immunotherapy is a remarkable breakthrough, offering the inimitable advantage of specific tumoricidal effects with reduced immune-associated cytotoxicity. However, existing platforms suffer from low efficacy, inability to induce strong immunogenic cell death (ICD), and restrained capacity of transforming immune-deserted tumors into immune-cultivated ones. Here, an innovative platform, perfluorooctyl bromide (PFOB) nanoemulsions holding MnO₂ nanoparticles (MBP), was developed to orchestrate cancer immunotherapy, serving as a theranostic nanoagent for MRI/CT dual-modality imaging and advanced ICD. By simultaneously depleting the GSH and eliciting the ICD effect via high-intensity focused ultrasound (HIFU) therapy, the MBP nanomedicine can regulate the tumor immune microenvironment by inducing maturation of dendritic cells (DCs) and facilitating the activation of CD8⁺ and CD4⁺ T cells. The synergistic GSH depletion and HIFU ablation also amplify the inhibition of tumor growth and lung metastasis. Together, these findings inaugurate a new strategy of tumor-targeted immunotherapy, realizing a novel therapeutics paradigm with great clinical significance.

Metal-Organic Framework (MOF)-Based Ultrasound-Responsive Dual-Sonosensitizer Nanoplatform for Hypoxic Cancer Therapy

Sonodynamic therapy (SDT), which uses reactive oxygen species to target tumors, has shown promise in the management of unresectable cancers. However, the hypoxic tumor environment limits SDT efficiency, making complete tumor destruction challenging. Here, a dual-sonosensitizer nanoplatform is developed by loading an alkyl radical generator (2,2-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, AIPH) onto a zirconium metal-organic framework (Zr-MOF). The Zr-MOF@AIPH nanoparticles (NPs) can produce singlet oxygen, which can kill tumor cells under normoxic conditions, as well as alkyl radicals, which can kill tumor cells under both normoxic and hypoxic conditions. The combination of these free radicals further enhances SDT efficiency. Meanwhile, the nitrogen generated owing to AIPH decomposition can reduce the cavitation threshold and enhance the acoustic cavitation effect, thereby promoting NP penetration at the tumor site. Moreover, Zr-MOF@AIPH NPs exhibit good photoacoustic, fluorescence, and ultrasound imaging abilities due to their porphyrin-based structure and the nitrogen generated, which can remotely control NP delivery and determine the optimal therapeutic time window, ensuring the maximization of SDT efficiency. In vitro and in vivo examinations prove the superior antitumor efficacy, excellent biocompatibility, and favorable imaging ability of Zr-MOF@AIPH. This study spearheads the charge toward improving SDT efficacy in hypoxic environments via a combination of complementary sonosensitizers.

Fabrication of Injectable Chitosan-Chondroitin Sulfate Hydrogel Embedding Kartogenin-Loaded Microspheres as an Ultrasound-Triggered Drug Delivery System for Cartilage Tissue Engineering

Ultrasound-responsive microspheres (MPs) derived from natural polysaccharides and injectable hydrogels have been widely investigated as a biocompatible, biodegradable, and controllable drug delivery system and cell scaffolds for tissue engineering. In this study, kartogenin (KGN) loaded poly (lactide-co-glycolic acid) (PLGA) MPs (MPs@KGN) were fabricated by premix membrane emulsification (PME) method which were sonicated by an ultrasound transducer. Furthermore, carboxymethyl chitosan-oxidized chondroitin sulfate (CMC-OCS) hydrogel were prepared via the Schiff’ base reaction-embedded MPs to produce a CMC-OCS/MPs scaffold. In the current work, morphology, mechanical property, porosity determination, swelling property, in vitro degradation, KGN release from scaffolds, cytotoxicity, and cell bioactivity were investigated. The results showed that MPs presented an obvious collapse after ultrasound treatment. The embedded PLGA MPs could enhance the compressive elastic modulus of soft CMC-OCS hydrogel. The cumulative release KGN from MPs exhibited a slow rate which would display an appropriate collapse after ultrasound, allowing KGN to maintain a continuous concentration for at least 28 days. Moreover, the composite CMC-OCS@MPs scaffolds exhibited faster gelation, lower swelling ratio, and lower in vitro degradation. CCK-8 and LIVE/DEAD staining showed these scaffolds did not influence rabbit bone marrow mesenchymal stem cells (rBMMSCs) proliferation. Then these scaffolds were cultured with rBMMSCs for 2 weeks, and the immunofluorescent staining of collagen II (COL-2) showed that CMC-OCS hydrogel embedded with MPs@KGN (CMC-OCS@MPs@KGN) with ultrasound had the ability to increase the COL-2 synthesis. Overall, due to the improved mechanical property and the ability of sustained KGN release, this injectable hydrogel with ultrasound-responsive property is a promising system for cartilage tissue engineering.

High-Intensity Focused Ultrasound: A Review of Mechanisms and Clinical Applications

High Intensity Focused Ultrasound (HIFU) is an emerging and increasingly useful modality in the treatment of cancer and other diseases. Although traditional use of ultrasound at lower frequencies has primarily been for diagnostic imaging purposes, the development of HIFU has allowed this particular modality to expand into therapeutic use. This non-invasive and acoustic method involves the use of a piezoelectric transducer to deliver high-energy pulses in a spatially coordinated manner, while minimizing damage to tissue outside the target area. This review describes the history of the development of diagnostic and therapeutic ultrasound and explores the biomedical applications utilizing HIFU technology including thermally ablative treatment, therapeutic delivery mechanisms, and neuromodulatory phenomena. The application of HIFU across various tumor types in multiple organ systems is explored in depth, with particular attention to successful models of HIFU in the treatment of various medical conditions. Basic mechanisms, preclinical models, previous clinical use, and ongoing clinical trials are comparatively discussed. Recent advances in HIFU across multiple medical fields reveal the growing importance of this biomedical technology for the care of patients and for the development of possible pathways for the future use of HIFU as a commonplace treatment modality.

Therapeutic oxygen delivery by perfluorocarbon-based colloids

After the protocol-related indecisive clinical trial of Oxygent, a perfluorooctylbromide/phospholipid nanoemulsion, in cardiac surgery, that often unduly assigned the observed untoward effects to the product, the development of perfluorocarbon (PFC)-based O₂ nanoemulsions ("blood substitutes") has come to a low. Yet, significant further demonstrations of PFC O₂-delivery efficacy have continuously been reported, such as relief of hypoxia after myocardial infarction or stroke; protection of vital organs during surgery; potentiation of O₂-dependent cancer therapies, including radio-, photodynamic-, chemo- and immunotherapies; regeneration of damaged nerve, bone or cartilage; preservation of organ grafts destined for transplantation; and control of gas supply in tissue engineering and biotechnological productions. PFC colloids capable of augmenting O₂ delivery include primarily injectable PFC nanoemulsions, microbubbles and phase-shift nanoemulsions. Careful selection of PFC and other colloid components is critical. The basics of O₂ delivery by PFC nanoemulsions will be briefly reminded. Improved knowledge of O₂ delivery mechanisms has been acquired. Advanced, size-adjustable O₂-delivering nanoemulsions have been designed that have extended room-temperature shelf-stability. Alternate O₂ delivery options are being investigated that rely on injectable PFC-stabilized microbubbles or phase-shift PFC nanoemulsions. The latter combine prolonged circulation in the vasculature, capacity for penetrating tumor tissues, and acute responsiveness to ultrasound and other external stimuli. Progress in microbubble and phase-shift emulsion engineering, control of phase-shift activation (vaporization), understanding and control of bubble/ultrasound/tissue interactions is discussed. Control of the phase-shift event and of microbubble size require utmost attention. Further PFC-based colloidal systems, including polymeric micelles, PFC-loaded organic or inorganic nanoparticles and scaffolds, have been devised that also carry substantial amounts of O₂. Local, on-demand O₂ delivery can be triggered by external stimuli, including focused ultrasound irradiation or tumor microenvironment. PFC colloid functionalization and targeting can help adjust their properties for specific indications, augment their efficacy, improve safety profiles, and expand the range of their indications. Many new medical and biotechnological applications involving fluorinated colloids are being assessed, including in the clinic. Further uses of PFC-based colloidal nanotherapeutics will be briefly mentioned that concern contrast diagnostic imaging, including molecular imaging and immune cell tracking; controlled delivery of therapeutic energy, as for noninvasive surgical ablation and sonothrombolysis; and delivery of drugs and genes, including across the blood-brain barrier. Even when the fluorinated colloids investigated are designed for other purposes than O₂ supply, they will inevitably also carry and deliver a certain amount of O₂, and may thus be considered for O₂ delivery or co-delivery applications. Conversely, O₂-carrying PFC nanoemulsions possess by nature a unique aptitude for ¹⁹F MR imaging, and hence, cell tracking, while PFC-stabilized microbubbles are ideal resonators for ultrasound contrast imaging and can undergo precise manipulation and on-demand destruction by ultrasound waves, thereby opening multiple theranostic opportunities.

An Advanced In Situ Magnetic Resonance Imaging and Ultrasonic Theranostics Nanocomposite Platform: Crossing the Blood-Brain Barrier and Improving the Suppression of Glioblastoma Using Iron-Platinum Nanoparticles in Nanobubbles

Glioblastoma (GBM) is one of the deadliest and most invasive brain cancers/gliomas, and there is currently no established way to treat this disease. The treatment of GBM typically involves intracranial surgery followed by chemotherapy. However, the blood-brain barrier (BBB) impedes the delivery of the chemotherapeutic drug, making the treatment challenging. In this study, we embedded a chemotherapeutic drug and other nanomaterials into a nanobubble (NB), utilized active tracking and other guidance mechanisms to guide the nanocomposite to the tumor site, and then used high-intensity focused ultrasound oscillation to burst the nanobubbles, generating a transient cavitation impact on the BBB and allowing the drug to bypass it and reach the brain. FePt enhances the resolution of T2-weighted magnetic resonance imaging images and has magnetic properties that help guide the nanocomposite to the tumor location. FePt nanoparticles were loaded into the hydrophobic core of the NBs along with doxorubicin to form a bubble-based drug delivery system (Dox-FePt@NB). The surface of the NBs is modified with a targeting ligand, transferrin (Dox-FePt@NB-Tf), giving the nanocomposite active tracking abilities. The Dox-FePt@NB-Tf developed in the present study represents a potential breakthrough in GBM treatment through improved drug delivery and biological imaging.

A pH/ultrasonic dual-response step-targeting enterosoluble granule for combined sonodynamic-chemotherapy guided via gastrointestinal tract imaging in orthotopic colorectal cancer

Colorectal cancer is one of the malignant tumors with high morbidity and lethality. Its efficient diagnosis and treatment has important significance. In this study, the orthotopic cancer model mouse, which could perfectly simulate clinical inflammatory colorectal cancer, was constructed by chemical induction. Based on this model, a new pH/ultrasonic dual-response, step-targeting and precisely controlled-release enteric-coated granule was designed for the combined sonodynamic (SDT)-chemotherapy. The enteric-coated granule was fabricated by enwrapping carboxymethyl chitosan (CMC) on folic acid-modified phospholipid (SLB-FA) encapsulating mesoporous silicon-coated gold nanoparticles loaded with chlorin (Ce6) and doxorubicin hydrochloride (DOX), titled as Au@mSiO2/Ce6/DOX/SLB-FA@CMC (GMCDS-FA@CMC). The diameter of the Au@mSiO2/Ce6/DOX/SLB-FA (GMCDS-FA) nanoprobe was 61.21 nm and that of the GMCDS-FA@CMC enteric-coated granule was 1.1 μm. MTT results showed that the cell survival rate was still as high as 76.55 ± 1.27% when the concentration of GMCDS-FA was up to 200 μg mL-1, which can indicate the low cytotoxicity of the nanoprobe. According to CT imaging, the enteric-coated granule had the highest concentration in the colorectum of the orthotopic cancer mouse after 7-9 h with oral administration, and was nearly metabolized out of the body after 24 h. The in vitro and in vivo experiments showed that the targeting enteric-coated granule had the best effect of treatment and desired prognosis after combined SDT-chemotherapy.

Stimuli-responsive natural gums-based drug delivery systems for cancer treatment

Chemotherapy as the main cancer treatment method has non-specific effects and various side-effects. Accordingly, significant attempts have been conducted to enhance its efficacy through design and development of "smart" drug delivery systems (DDSs). In this context, natural gums, as a nice gift by the nature, can be exploited as stimuli-responsive DDSs for cancer treatment in part due to their renewability, availability, low cost, bioactivity, biocompatibility, low immunogenicity, biodegradability, and acceptable stability in both in vitro and in vivo conditions. However, some shortcomings (e.g., poor mechanical properties and high hydration rate) restrict their biomedical application ranges that can be circumvented through modification process (e.g., grafting of stimuli-responsive polymers or small molecules) to obtain tailored biomaterials. This review article aimed to compile the stimuli-responsive DDSs based on natural gums. In addition, different types of stimuli, the fundamental features of natural gums, as well as their chemical modification approaches are also shortly highlighted.

Enhancement of Therapies for Glioblastoma (GBM) Using Nanoparticle-based Delivery Systems

Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumor. Current FDA-approved treatments include surgical resection, radiation, and chemotherapy, while hyperthermia, immunotherapy, and most relevantly, nanoparticle (NP)-mediated delivery systems or combinations thereof have shown promise in preclinical studies. Drug-carrying NPs are a promising approach to brain delivery as a result of their potential to facilitate the crossing of the blood-brain barrier (BBB) via two main types of transcytosis mechanisms: adsorptive-mediated transcytosis (AMT) and receptor-mediated transcytosis (RMT). Their ability to accumulate in the brain can thus provide local sustained release of tumoricidal drugs at or near the site of GBM tumors. NP-based drug delivery has the potential to significantly reduce drug-related toxicity, increase specificity, and consequently improve the lifespan and quality of life of patients with GBM. Due to significant advances in the understanding of the molecular etiology and pathology of GBM, the efficacy of drugs loaded into vectors targeting this disease has increased in both preclinical and clinical settings. Multitargeting NPs, such as those incorporating multiple specific targeting ligands, are an innovative technology that can lead to decreased off-target effects while simultaneously having increased accumulation and action specifically at the tumor site. Targeting ligands can include antibodies, or fragments thereof, and peptides or small molecules, which can result in a more controlled drug delivery system compared to conventional drug treatments. This review focuses on GBM treatment strategies, summarizing current options and providing a detailed account of preclinical findings with prospective NP-based approaches aimed at improving tumor targeting and enhancing therapeutic outcomes for GBM patients.

In vitro evaluation of polymeric nanoparticles with a fluorine core for drug delivery triggered by focused ultrasound

Polymeric nanoparticles are being intensively investigated as drug carriers. Their efficiency could be enhanced if the drug release can be triggered using an external stimulus such as ultrasound. This approach is possible using current commercial apparatus that combine focused ultrasound with MRI to perform ultrasonic surgery. In this approach, nanoparticles made of a perfluoro-octyl bromide core and a thick polymeric (PLGA-PEG) shell may represent suitable drug carriers. Indeed, their perfluorocarbon core are detectable by ¹⁹F MRI, while their polymeric shell can encapsulate drugs. However, their applicability in ultrasound-triggered drug delivery remains to be proven. To do so, we used Nile red as a model drug and we measured its release from the polymeric shell by spectrofluorometry. In the absence of ultrasound, only a small amount of Nile red release was measured (<5%). Insonations were performed in a controlled environment using a 1.1 MHz transducer emitting tone bursts for a few minutes, whereas a focused broadband hydrophone was used to detect the occurrence of cavitation. In the absence of detectable inertial cavitation, less than 5% of Nile red was released. In the presence of detectable inertial cavitation, Nile red release was ranging from 10% to 100%, depending of the duty cycle, acoustic pressure, and tank temperature (25 or 37 °C). Highest releases were obtained only for duty cycles of 25% at 37 °C and 50% at 25 °C and for a peak-to-peak acoustic pressure above 12.7 MPa. Electron microscopy and light scattering measurements showed a slight modification in the nanoparticle morphology only at high release contents. The occurrence of strong inertial cavitation is thus a prerequisite to induce drug release for these nanoparticles. Since strong inertial cavitation can lead to many unwanted biological effects, these nanoparticles may not be suitable for a therapeutic application using ultrasound-triggered drug delivery.

Addressing BBB Heterogeneity: A New Paradigm for Drug Delivery to Brain Tumors

Effective treatments for brain tumors remain one of the most urgent and unmet needs in modern oncology. This is due not only to the presence of the neurovascular unit/blood-brain barrier (NVU/BBB) but also to the heterogeneity of barrier alteration in the case of brain tumors, which results in what is referred to as the blood-tumor barrier (BTB). Herein, we discuss this heterogeneity, how it contributes to the failure of novel pharmaceutical treatment strategies, and why a "whole brain" approach to the treatment of brain tumors might be beneficial. We discuss various methods by which these obstacles might be overcome and assess how these strategies are progressing in the clinic. We believe that by approaching brain tumor treatment from this perspective, a new paradigm for drug delivery to brain tumors might be established.

Intraperitoneal chemotherapy of the peritoneal surface using high-intensity ultrasound (HIUS): investigation of technical feasibility, safety and possible limitations

Introduction: The penetration of chemotherapeutic drugs into peritoneal nodules remains at levels well below 1 mm, thus significantly limiting the antitumor effect of intraperitoneal chemotherapy (IPC). Recently, high-Intensity ultrasound (HIUS) has been discovered as a potential tool to significantly improve peritoneal diffusion rates. Despite promising preliminary data, basic aspects regarding its technical feasibility, safety and possible limitations remain unclear. This study aims to enhance our current understanding of HIUS and test its applicability using an ex-vivo swine model. Methods: Three postmortem swine were subject to laparotomy and consecutive lavage with 0.9%NaCl saline and HIUS application. For this purpose, a large HIUS radiating pen was introduced into the abdominal cavity and HIUS was applied on two of the four abdominal quadrants for 300 seconds each at an output power of 70 W, 50 % amplitude and 20 kHz frequency. Following the procedure, small intestinal tissue samples were retrieved for further analyses. Results: Peritoneal and subperitoneal layers showed structural changes only visible on a microscopic level. The peritoneal layer was transformed into a mesh-like structure while the subperitoneal layer (depth of 142 +/- 28 µm) exhibited microcavities and vascular detachment from surrounding tissues. No bowel rupture or vascular perforations were observed. Conclusions: Our data indicate that HIUS is a technically feasible and safe add-on procedure for intraperitoneal chemotherapy (IPC) with measurable microscopic changes on the peritoneal surface. Pretreatment of the abdominal cavity with HIUS could significantly improve IPC efficacy. Further studies are required to optimize and evaluate this novel approach.

Perfluorocarbons-Based 19F Magnetic Resonance Imaging in Biomedicine

Fluorine-19 (¹⁹F) magnetic resonance (MR) molecular imaging is a promising noninvasive and quantitative molecular imaging approach with intensive research due to the high sensitivity and low endogenous background signal of the ¹⁹F atom in vivo. Perfluorocarbons (PFCs) have been used as blood substitutes since 1970s. More recently, a variety of PFC nanoparticles have been designed for the detection and imaging of physiological and pathological changes. These molecular imaging probes have been developed to label cells, target specific epitopes in tumors, monitor the prognosis and therapy efficacy and quantitate characterization of tumors and changes in tumor microenvironment noninvasively, therefore, significantly improving the prognosis and therapy efficacy. Herein, we discuss the recent development and applications of ¹⁹F MR techniques with PFC nanoparticles in biomedicine, with particular emphasis on ligand-targeted and quantitative ¹⁹F MR imaging approaches for tumor detection, oxygenation measurement, smart stimulus response and therapy efficacy monitoring, et al.

Controlled anti-cancer drug release through advanced nano-drug delivery systems: Static and dynamic targeting strategies

Advances in nanomedicine, including early cancer detection, targeted drug delivery, and personalized approaches to cancer treatment are on the rise. For example, targeted drug delivery systems can improve intracellular delivery because of their multifunctionality. Novel endogenous-based and exogenous-based stimulus-responsive drug delivery systems have been proposed to prevent the cancer progression with proper drug delivery. To control effective dose loading and sustained release, targeted permeability and individual variability can now be described in more-complex ways, such as by combining internal and external stimuli. Despite these advances in release control, certain challenges remain and are identified in this research, which emphasizes the control of drug release and applications of nanoparticle-based drug delivery systems. Using a multiscale and multidisciplinary approach, this study investigates and analyzes drug delivery and release strategies in the nanoparticle-based treatment of cancer, both mathematically and clinically.

Modulation of Tumor Hypoxia by pH-Responsive Liposomes to Inhibit Mitochondrial Respiration for Enhancing Sonodynamic Therapy

Background and Purpose

Sonodynamic therapy (SDT) has been widely used for the noninvasive treatment of solid tumors, but the hypoxic tumor microenvironment limits its therapeutic effect. The current methods of reoxygenation to enhance SDT have limitations, prompting reconsideration of the design of therapeutic approaches. Here, we developed a tumor microenvironment-responsive nanoplatform by reducing oxygen consumption to overcome hypoxia-induced resistance to cancer therapy.

Methods

A pH-responsive drug-loaded liposome (MI-PEOz-lip) was prepared and used to reduce oxygen consumption, attenuating hypoxia-induced resistance to SDT and thereby improving therapeutic efficiency. Photoacoustic imaging (PAI) and fluorescence imaging (FI) of MI-PEOz-lip were evaluated in vitro and in breast xenograft tumor models. The pH-sensitive functionality of MI-PEOz-lip was applied for pH-triggered cargo release, and its capacity was evaluated. The MI-PEOz-lip-mediated SDT effect was compared with other treatments in vivo.

Results

MI-PEOz-lip was demonstrated to specifically accumulate in tumors. Metformin molecules in liposomes selectively accumulate in tumors by pH-responsive drug release to inhibit the mitochondrial respiratory chain while releasing IR780 to the tumor area. These pH-responsive liposomes demonstrated PAI and FI imaging capabilities in vitro and in vivo, providing potential for treatment guidance and monitoring. In particular, the prepared MI-PEOz-lip combined with ultrasound irradiation effectively inhibited breast tumors by producing toxic reactive singlet oxygen species (ROS), while the introduction of metformin inhibited mitochondrial respiration and reduced tumor oxygen consumption, resulting in excellent sonodynamic therapy performance compared with other treatments.

Conclusion

In this study, we present a novel strategy to achieve high therapeutic efficacy of SDT by the rational design of multifunctional nanoplatforms. This work provides a new strategy that can solve the current problems of inefficient oxygen delivery strategies and weaken resistance to various oxygen-dependent therapies.

Stimuli-Responsive Nanomaterials for Application in Antitumor Therapy and Drug Delivery

The new era of nanotechnology has produced advanced nanomaterials applicable to various fields of medicine, including diagnostic bio-imaging, chemotherapy, targeted drug delivery, and biosensors. Various materials are formed into nanoparticles, such as gold nanomaterials, carbon quantum dots, and liposomes. The nanomaterials have been functionalized and widely used because they are biocompatible and easy to design and prepare. This review mainly focuses on nanomaterials responsive to the external stimuli used in drug-delivery systems. To overcome the drawbacks of conventional therapeutics to a tumor, the dual- and multi-responsive behaviors of nanoparticles have been harnessed to improve efficiency from a drug delivery point of view. Issues and future research related to these nanomaterial-based stimuli sensitivities and the scope of stimuli-responsive systems for nanomedicine applications are discussed.