Tumor target amplification: Implications for nano drug delivery systems

Unlocking nature's arsenal: Nanotechnology for targeted delivery of venom toxins in cancer therapy

AIM

The aim of the present review is to shed light on the nanotechnological approaches adopted to overcome the shortcomings associated with the delivery of venom peptides which possess inherent anti-cancer properties.

BACKGROUND

Venom peptides although have been reported to demonstrate anti-cancer effects, they suffer from several disadvantages such as in vivo instability, off-target adverse effects, limited drug loading and low bioavailability. This review presents a comprehensive compilation of different classes of nanocarriers while underscoring their advantages, disadvantages and potential to carry such peptide molecules for in vivo delivery. It also discusses various nanotechnological aspects such as methods of fabrication, analytical tools to assess these nanoparticulate formulations, modulation of nanocarrier polymer properties to enhance loading capacity, stability and improve their suitability to carry toxic peptide drugs.

CONCLUSION

Nanotechnological approaches bear great potential in delivering venom peptide-based molecules as anticancer agents by enhancing their bioavailability, stability, efficacy as well as offering a spatiotemporal delivery approach. However, the challenges associated with toxicity and biocompatibility of nanocarriers must be duly addressed.

PERSPECTIVES

The everlasting quest for new breakthroughs for safer delivery of venom peptides in human subjects is fuelled by unmet clinical needs in the current landscape of chemotherapy. In addition, exhaustive efforts are required in obtaining and purifying the venom peptides followed by designing and optimizing scale up technologies.

Tumor-Homing Peptides as Crucial Component of Magnetic-Based Delivery Systems: Recent Developments and Pharmacoeconomical Perspective

According to data from the World Health Organization (WHO), cancer is considered to be one of the leading causes of death worldwide, and new therapeutic approaches, especially improved novel cancer treatment regimens, are in high demand. Considering that many chemotherapeutic drugs tend to have poor pharmacokinetic profiles, including rapid clearance and limited on-site accumulation, a combined approach with tumor-homing peptide (THP)-functionalized magnetic nanoparticles could lead to remarkable improvements. This is confirmed by an increasing number of papers in this field, showing that the on-target peptide functionalization of magnetic nanoparticles improves their penetration properties and ensures tumor-specific binding, which results in an increased clinical response. This review aims to highlight the potential applications of THPs in combination with magnetic carriers across various fields, including a pharmacoeconomic perspective.

Photodynamically Tumor Vessel Destruction Amplified Tumor Targeting of Nanoparticles for Efficient Chemotherapy

Efficient tumor-targeted drug delivery is still a challenging and currently unbreakable bottleneck in chemotherapy for tumors. Nanomedicines based on passive or active targeting strategy have not yet achieved convincing chemotherapeutic benefits in the clinic due to the tumor heterogeneity. Inspired by the efficient inflammatory-cell recruitment to acute clots, we constructed a two-component nanosystem, which is composed of an RGD-modified pyropheophorbide-a (Ppa) micelle (PPRM) that mediates the tumor vascular-targeted photodynamic reaction to activate local coagulation and subsequently transmits the coagulation signals to the circulating clot-targeted CREKA peptide-modified camptothecin (CPT)-loaded nanodiscs (CCNDs) for amplifying tumor targeting. PPRM could effectively bind with the tumor vasculature and induce sufficient local thrombus by a photodynamic reaction. Local photodynamic reaction-induced tumor target amplification greatly increased the tumor accumulation of CCND by 4.2 times, thus significantly enhancing the chemotherapeutic efficacy in the 4T1 breast tumor model. In other words, this study provides a powerful platform to amplify tumor-specific drug delivery by taking advantage of the efficient crosstalk between the PPRM-activated coagulation cascade and clot-targeted CCND.

Biosensor-Enhanced Organ-on-a-Chip Models for Investigating Glioblastoma Tumor Microenvironment Dynamics

Glioblastoma, an aggressive primary brain tumor, poses a significant challenge owing to its dynamic and intricate tumor microenvironment. This review investigates the innovative integration of biosensor-enhanced organ-on-a-chip (OOC) models as a novel strategy for an in-depth exploration of glioblastoma tumor microenvironment dynamics. In recent years, the transformative approach of incorporating biosensors into OOC platforms has enabled real-time monitoring and analysis of cellular behaviors within a controlled microenvironment. Conventional in vitro and in vivo models exhibit inherent limitations in accurately replicating the complex nature of glioblastoma progression. This review addresses the existing research gap by pioneering the integration of biosensor-enhanced OOC models, providing a comprehensive platform for investigating glioblastoma tumor microenvironment dynamics. The applications of this combined approach in studying glioblastoma dynamics are critically scrutinized, emphasizing its potential to bridge the gap between simplistic models and the intricate in vivo conditions. Furthermore, the article discusses the implications of biosensor-enhanced OOC models in elucidating the dynamic features of the tumor microenvironment, encompassing cell migration, proliferation, and interactions. By furnishing real-time insights, these models significantly contribute to unraveling the complex biology of glioblastoma, thereby influencing the development of more accurate diagnostic and therapeutic strategies.

From complexity to clarity: unravelling tumor heterogeneity through the lens of tumor microenvironment for innovative cancer therapy

Despite the tremendous clinical successes recorded in the landscape of cancer therapy, tumor heterogeneity remains a formidable challenge to successful cancer treatment. In recent years, the emergence of high-throughput technologies has advanced our understanding of the variables influencing tumor heterogeneity beyond intrinsic tumor characteristics. Emerging knowledge shows that drivers of tumor heterogeneity are not only intrinsic to cancer cells but can also emanate from their microenvironment, which significantly favors tumor progression and impairs therapeutic response. Although much has been explored to understand the fundamentals of the influence of innate tumor factors on cancer diversity, the roles of the tumor microenvironment (TME) are often undervalued. It is therefore imperative that a clear understanding of the interactions between the TME and other tumor intrinsic factors underlying the plastic molecular behaviors of cancers be identified to develop patient-specific treatment strategies. This review highlights the roles of the TME as an emerging factor in tumor heterogeneity. More particularly, we discuss the role of the TME in the context of tumor heterogeneity and explore the cutting-edge diagnostic and therapeutic approaches that could be used to resolve this recurring clinical conundrum. We conclude by speculating on exciting research questions that can advance our understanding of tumor heterogeneity with the goal of developing customized therapeutic solutions.

Advancing cancer theranostics through biomimetics: A comprehensive review

Nanotheranostics, especially those employing biomimetic approaches, are of substantial interest for molecular imaging and cancer therapy. The incorporation of diagnostics and therapeutics, known as cancer theranostics, represents a promising strategy in modern oncology. Biomimetics, inspired by nature, offers a multidisciplinary avenue with potential in advancing cancer theranostics. This review comprehensively analyses recent progress in biomimetics-based cancer theranostics, emphasizing its role in overcoming current treatment challenges, with a focus on breast, prostate, and skin cancers. Biomimetic approaches have been explored to address multidrug resistance (MDR), emphasizing their role in immunotherapy and photothermal therapy. The specific areas covered include biomimetic drug delivery systems bypassing MDR mechanisms, biomimetic platforms for immune checkpoint blockade, immune cell modulation, and photothermal tumor ablation. Pretargeting techniques enhancing radiotherapeutic agent uptake are discussed, along with a comprehensive review of clinical trials of global nanotheranostics. This review delves into biomimetic materials, nanotechnology, and bioinspired strategies for cancer imaging, diagnosis, and targeted drug delivery. These include imaging probes, contrast agents, and biosensors for enhanced specificity and sensitivity. Biomimetic strategies for targeted drug delivery involve the design of nanoparticles, liposomes, and hydrogels for site-specific delivery and improved therapeutic efficacy. Overall, this current review provides valuable information for investigators, clinicians, and biomedical engineers, offering insights into the latest biomimetics applications in cancer theranostics. Leveraging biomimetics aims to revolutionize cancer diagnosis, treatment, and patient outcomes.

Therapeutic Approaches of Dual-targeted Nanomedicines for Tumor Multidrug Resistance

Currently, the main cause of cancer chemotherapy failure is multi-drug resistance (MDR), which involves a variety of complex mechanisms. Compared with traditional small-molecule chemotherapy, targeted nanomedicines offer promising alternative strategies as an emerging form of therapy, especially active targeted nanomedicines. However, although single-targeted nanomedicines have made some progress in tumor therapy, the complexity of tumor microenvironment and tumor heterogeneity limits their efficacy. Dual-targeted nanomedicines can simultaneously target two tumor-specific factors that cause tumor MDR, which have the potential in overcoming tumor MDR superior to single-targeted nanomedicines by further enhancing cell uptake and cytotoxicity in new forms, as well as the effectiveness of tumor-targeted delivery. This review discusses tumor MDR mechanisms and the latest achievements applied to dual-targeted nanomedicines in tumor MDR.

Molecular targets, therapeutic agents and multitasking nanoparticles to deal with cancer stem cells: A narrative review

There is increasing evidence that malignant tumors are initiated and maintained by a sub-population of tumor cells that have similar biological properties to normal adult stem cells. This very small population of Cancer Stem Cells (CSC) comprises tumor initiating cells responsible for cancer recurrence, drug resistance and metastasis. Conventional treatments such as chemotherapy, radiotherapy and surgery, in addition to being potentially toxic and non-specific, may paradoxically increase the population, spread and survival of CSCs. Next-generation sequencing and omics technologies are increasing our understanding of the pathways and factors involved in the development of CSCs, and can help to discover new therapeutic targets against CSCs. In addition, recent advances in nanomedicine have provided hope for the development of optimal specific therapies to eradicate CSCs. Moreover, the use of artificial intelligence and nano-informatics can elucidate new drug targets, and help to design drugs and nanoparticles (NPs) to deal with CSCs. In this review, we first summarize the properties of CSCs and describe the signaling pathways and molecular characteristics responsible for the emergence and survival of CSCs. Also, the location of CSCs within the tumor and the effect of host factors on the creation and maintenance of CSCs are discussed. Newly discovered molecular targets involved in cancer stemness and some novel therapeutic compounds to combat CSCs are highlighted. The optimum properties of anti-CSC NPs, including blood circulation and stability, tumor accumulation and penetration, cellular internalization, drug release, endosomal escape, and aptamers designed for specific targeting of CSCs are covered. Finally, some recent smart NPs designed for therapeutic and theranostic purposes to overcome CSCs are discussed.

Dual receptor specific nanoparticles targeting EGFR and PD-L1 for enhanced delivery of docetaxel in cancer therapy

Dual-receptor targeted (DRT) nanoparticles which contain two distinct targeting agents may exhibit higher cell selectivity, cellular uptake, and cytotoxicity toward cancer cells than single-ligand targeted nanoparticle systems without additional functionality. The purpose of this study is to prepare DRT poly(lactic-co-glycolic acid) (PLGA) nanoparticles for targeting the delivery of docetaxel (DTX) to the EGFR and PD-L1 receptor positive cancer cells such as human glioblastoma multiform (U87-MG) and human non-small cell lung cancer (A549) cell lines. Anti-EGFR and anti-PD-L1 antibody were decorated on DTX loaded PLGA nanoparticles to prepare DRT-DTX-PLGA via. single emulsion solvent evaporation method. Physicochemical characterizations of DRT-DTX-PLGA, such as particle size, zeta-potential, morphology, and in vitro DTX release were also evaluated. The average particle size of DRT-DTX-PLGA was 124.2 ± 1.1 nm with spherical and smooth morphology. In the cellular uptake study, the DRT-DTX-PLGA endocytosed by the U87-MG and A549 cells was single ligand targeting nanoparticle. From the in vitro cell cytotoxicity, and apoptosis studies, we reported that DRT-DTX-PLGA exhibited high cytotoxicity and enhanced the apoptotic cell compared to the single ligand-targeted nanoparticle. The dual receptor mediated endocytosis of DRT-DTX-PLGA showed a high binding affinity effect that leads to high intracellular DTX concentration and exhibited high cytotoxic properties. Thus, DRT nanoparticles have the potential to improve cancer therapy by providing selectivity over single-ligand-targeted nanoparticles.

Large-scale assessment of pros and cons of autopsy-derived or tumor-matched tissues as the norms for gene expression analysis in cancers

Normal tissues are essential for studying disease-specific differential gene expression. However, healthy human controls are typically available only in postmortal/autopsy settings. In cancer research, fragments of pathologically normal tissue adjacent to tumor site are frequently used as the controls. However, it is largely underexplored how cancers can systematically influence gene expression of the neighboring tissues. Here we performed a comprehensive pan-cancer comparison of molecular profiles of solid tumor-adjacent and autopsy-derived "healthy" normal tissues. We found a number of systemic molecular differences related to activation of the immune cells, intracellular transport and autophagy, cellular respiration, telomerase activation, p38 signaling, cytoskeleton remodeling, and reorganization of the extracellular matrix. The tumor-adjacent tissues were deficient in apoptotic signaling and negative regulation of cell growth including G2/M cell cycle transition checkpoint. We also detected an extensive rearrangement of the chemical perception network. Molecular targets of 32 and 37 cancer drugs were over- or underexpressed, respectively, in the tumor-adjacent norms. These processes may be driven by molecular events that are correlated between the paired cancer and adjacent normal tissues, that mostly relate to inflammation and regulation of intracellular molecular pathways such as the p38, MAPK, Notch, and IGF1 signaling. However, using a model of macaque postmortal tissues we showed that for the 30 min - 24-hour time frame at 4ºC, an RNA degradation pattern in lung biosamples resulted in an artifact "differential" expression profile for 1140 genes, although no differences could be detected in liver. Thus, such concerns should be addressed in practice.

Cyclic amplification of intracellular ROS boosts enzymatic prodrug activation for enhanced chemo-immunotherapy

Tumor-associated enzyme activated prodrug is a potential strategy to overcome the limitations of chemotherapeutic agents. However, the efficiency of enzymatic prodrug activation is limited by the inability to reach adequate enzyme levels in vivo. Herein, we report an intelligent nanoplatform with cyclic amplification of intracellular reactive oxygen species (ROS) that significantly up-regulates the expression of tumor-associated enzyme, NAD(P)H:quinone oxidoreductase 1 (NQO1), to efficiently activate the prodrug of doxorubicin (DOX) for enhanced chemo-immunotherapy. The nanoplatform termed as CF@NDOX was fabricated by self-assembly of the amphiphilic cinnamaldehyde (CA) containing poly(thioacetal) conjugated with ferrocene (Fc) and poly(ethylene glycol) (PEG) (TK-CA-Fc-PEG), which further encapsulated the NQO1 responsive prodrug of DOX (NDOX). After CF@NDOX accumulates in tumors, the TK-CA-Fc-PEG with ROS responsive thioacetal group responds to endogenous ROS in tumor to release CA, Fc or NDOX. CA induces mitochondria dysfunction and elevates the intracellular hydrogen peroxide (H2O2) levels, which react with Fc to generate highly oxidative hydroxyl radical (•OH) through Fenton reaction. The •OH not only promotes ROS cyclic amplification but also increase the expression of NQO1 through Keap1-Nrf2 pathway regulation, which further boost the prodrug activation of NDOX for enhanced chemo-immunotherapy. Overall, our well-designed intelligent nanoplatform provides a tactic to enhance the antitumor efficacy of tumor-associated enzyme activated prodrug. STATEMENT OF SIGNIFICANCE: In this work, a smart nanoplatform CF@NDOX with intracellular ROS cyclic amplification for continuous upregulation of NQO1 enzyme expression was innovatively designed. It could utilize Fenton reaction of Fc to increase the level of NQO1 enzyme and CA to increase the level of intracellular H2O2, thereby facilitating the continuous Fenton reaction. This design allowed for a sustained elevation of the NQO1 enzyme, and a more complete activation of the NQO1 enzyme in response to the prodrug NDOX. This smart nanoplatform can achieve a desirable anti-tumor effect with the combined therapy of chemotherapy and ICD effects.

Dual-Ligand Synergistic Targeting Anti-Tumor Nanoplatforms with Cascade-Responsive Drug Release

Dual-ligand targeting drug delivery nanoplatforms are considered a promising tool for enhancing the specificity of chemotherapy. However, serious off-target delivery has been observed in current dual-ligand targeting nanoplatforms, as each ligand can independently recognize receptors on the cell membrane surface and guide drug nanocarriers to different cells. To overcome this barrier, a dual-ligand synergistic targeting (DLST) nanoplatform is developed, which can guide chemotherapy treatment specifically to cancer cells simultaneously overexpressing two receptors. This nanoplatform consists of a singlet oxygen (¹O₂) photosensitizer-loaded nanocarrier and a drug-loaded nanocarrier with ¹O₂ responsiveness, which were, respectively, decorated with a pair of complementary DNA sequences and two different ligands. For cancer cells overexpressing both receptors, two nanocarriers can be internalized in larger quantities to cause DNA hybridization-induced nanocarrier aggregation, which further activates ¹O₂-triggered drug release under light irradiation. For cells overexpressing a single receptor, only one type of nanocarrier can be internalized in a large quantity, leading to blocked drug release due to the ultrashort action radius of ¹O₂. In vivo evaluation showed this DLST nanoplatform displayed highly specific tumor treatment with minimized long-term toxicity. This is a highly efficient drug delivery system for DLST chemotherapy, holding great potential for clinical applications.

Particle Coupling Mechanism inspired Adsorption Optimization in Autonomous in Vivo Computing

While some commercial transceivers are available for capsule millirobots, no one has yet tackled the challenge of wireless communication between nanorobots inside the human body, which could be crucial for the control, and coordination of nanorobots. The Multi-agent system relies on information exchange by physical interactions or chemical secretions to perform complex tasks. Our previous work proposed a swarm coordination mechanism for tumor-target in an autonomous manner. To perform deterministic tasks, the method does not require prior knowledge of tumor location but the nanoparticles (NPs) swarm that follows simple migration principles. The biological gradient field (BGF) generated by tumors allows nanoswarms (NS) to cooperate and passively migrate to potential tumor sites. An autonomous computation strategy in vivo (ACS) is proposed based on particle coupling and adsorption optimization to improve NS aggregation and overall targeting efficiency in vivo. In addition, an evaluation system is established to evaluate the aggregation degree of NS and the drug leakage caused by the dissipation of NPs in complex vascular networks. By increasing the aggregation degree NS and reducing the effect of drug leakage, We are able to achieve an increase in global targeting efficiency to about 95%, which can be helpful in early-tumor detection, which can be helpful in early-tumor detection.Clinical relevance-Our investigation into autonomous swarm coordination and targeting of nanorobots in vivo represents a novel approach for early tumor detection, potentially achieving targeting efficiency of approximately 95% in complex vascular networks.

Multifunctional nanostructures: Intelligent design to overcome biological barriers

Over the past three decades, nanoscience has offered a unique solution for reducing the systemic toxicity of chemotherapy drugs and for increasing drug therapeutic efficiency. However, the poor accumulation and pharmacokinetics of nanoparticles are some of the key reasons for their slow translation into the clinic. The is intimately linked to the non-biological nature of nanoparticles and the aberrant features of solid cancer, which together significantly compromise nanoparticle delivery. New findings on the unique properties of tumors and their interactions with nanoparticles and the human body suggest that, contrary to what was long-believed, tumor features may be more mirage than miracle, as the enhanced permeability and retention based efficacy is estimated to be as low as 1%. In this review, we highlight the current barriers and available solutions to pave the way for approved nanoformulations. Furthermore, we aim to discuss the main solutions to solve inefficient drug delivery with the use of nanobioengineering of nanocarriers and the tumor environment. Finally, we will discuss the suggested strategies to overcome two or more biological barriers with one nanocarrier. The variety of design formats, applications and implications of each of these methods will also be evaluated.

Spatiotemporal dissection of tumor microenvironment via in situ sensing and monitoring in tumor-on-a-chip

Real-time monitoring in the tumor microenvironment provides critical insights of cancer progression and mechanistic understanding of responses to cancer treatments. However, clinical challenges and significant questions remain regarding assessment of limited clinical tissue samples, establishment of validated, controllable pre-clinical cancer models, monitoring of static versus dynamic markers, and the translation of insights gained from in vitro tumor microenvironments to systematic investigation and understanding in clinical practice. State-of-art tumor-on-a-chip strategies will be reviewed herein, and emerging real-time sensing and monitoring platforms for on-chip analysis of tumor microenvironment will also be examined. The integration of the sensors with tumor-on-a-chip platforms to provide spatiotemporal information of the tumor microenvironment and the associated challenges will be further evaluated. Though optimal integrated systems for in situ monitoring are still in evolution, great promises lie ahead that will open new paradigm for rapid, comprehensive analysis of cancer development and assist clinicians with powerful tools to guide the diagnosis, prognosis and treatment course in cancer.

Apoptosis-Amplified Assembly of Porphyrin Nanofiber Enhances Photodynamic Therapy of Oral Tumor

Oral squamous cell carcinoma (OSCC) is the most common oral cancer, having high recurrence and metastasis features. In addition to surgery, photodynamic therapy (PDT) is considered as another effective approach for OSCC treatment. The water solubility of currently available PDT photosensitizers (PSs) is poor, lowering their singlet oxygen (¹O₂) yield and consequent PDT efficiency. Strategies of PS assembly have been reported to increase ¹O₂ yield, but it is still possible to further enhance PDT efficiency. In this work, we utilized apoptosis to amplify the assembly of porphyrin nanofibers for enhanced PDT of OSCC. A water-soluble porphyrin derivative, Ac-Asp-Glu-Val-Asp-Asp-TPP (Ac-DEVDD-TPP), was designed for this purpose. Upon caspase-3 (Casp3, an activated enzyme during apoptosis) cleavage and laser irradiation, Ac-DEVDD-TPP was converted to D-TPP, which spontaneously self-assembled into porphyrin nanofibers, accompanied by 1.4-fold and 2.1-fold ¹O₂ generations in vitro and in cells, respectively. The as-formed porphyrin nanofiber induced efficient cell apoptosis and pyroptosis. In vivo experiments demonstrated that, compared with the scrambled control compound Ac-DEDVD-TPP, Ac-DEVDD-TPP led to 6.2-fold and 1.3-fold expressions of Casp3 in subcutaneous and orthotopic oral tumor models, respectively, and significantly suppressed the tumors. We envision that our strategy of apoptosis-amplified porphyrin assembly might be applied for OSCC treatment in the clinic in the near future.

Zwitterionic nanocapsules with pH- and thermal- responsiveness for drug-controlled release

The construction of an environmentally responsive drug-release system is of great significance for the treatment of special diseases. In particular, the construction of nanomaterials with pH- and thermal-responsiveness, which can effectively encapsulate drugs and control drug release, is becoming hot research. In this study, zwitterionic nanocapsules with stable core-shell structures were synthesized by inverse reversible addition-fragmentation transfer miniemulsion interfacial polymerization. To further study the structure and performance of the nanocapsules, the prepared nanocapsules were characterized by transmission electron microscopy, dynamic light dispersion, and zeta potential analysis. It was found that the nanocapsules had dual pH- and thermal- responsiveness, and the average particle size ranged from 178 to 142 nm when the temperature changed from 25 °C to 40 °C. In addition, bovine serum albumin (BSA) was encapsulated into nanocapsules, and sustained release experiments were conducted at 10 °C and 40 °C. The results showed that nanocapsules as carriers of BSA could achieve the purpose of sustained release of drugs, and showed different sustained release curves at different temperatures. Finally,in vitrocytotoxicity tests were performed to demonstrate the feasibility of their biomedical application. It is believed that the dual pH- and thermal- responsive nanocapsules are promising for drug-controlled release.

Construction of Artificial Controllable Aggregation Trojan Horse-Like Nanoplatform for Enhanced NIR-II Photothermal Therapy

Promoting the aggregation of nanoprobes at tumor sites and realizing precise imaging and treatment of tumors is still one of the important problems to be solved in the field of nanomedicine. Poly-2-phenylbenzobisthiazole (PB) is a novel conjugated polymer with good biocompatibility, excellent photothermal properties in the second near-infrared region (NIR-II), but poor water dispersibility. Herein, a novel self-assembly/polymerization two-in-one strategy was proposed to prepare a new family of poly-2-phenyl-benzobisthiazole-based nanoparticles. Because the hydrophobic polymer PB was well "camouflaged" in the hydrophilic polyphenol-metal networks, the prepared "Trojan horse-like" nanoparticle TF-PB exhibited good water dispersibility. Besides, TF-PB can play a role as a contrast agent for photoacoustic and magnetic resonance dual-modality imaging. When deferoxamine was artificially applied and interacted with TF-PB, the polyphenol-metal networks disintegrated and the hydrophobic material PB was exposed and started hydrophobic aggregation. Thus, it can be applied for precise enhanced photothermal therapy (PTT) in the NIR-II. Meanwhile, the aggregation process enabled non-invasive, fast, and accurate real-time monitoring by self-enhancing photoacoustic imaging. This work has realized the artificially controllable aggregation of photothermal materials in the tumor site, solved the limitations of traditional PTT, and also has good application prospects in clinical therapy.

Nanoenabled Tumor Energy Metabolism Disorder via Sonodynamic Therapy for Multidrug Resistance Reversal and Metastasis Inhibition

Cancer multidrug resistance (MDR) is an important reason that results in chemotherapy failure. As a main mechanism of MDR, overexpressed P-glycoprotein (P-gp) utilizes adenosine triphosphate (ATP) to actively pump chemotherapy drugs out of cells. In addition, metabolic reprogramming of drug-resistant tumor cells (DRTCs) exacerbates the specific hypoxic microenvironment and promotes tumor metastasis and recurrence. Therefore, we propose a novel sonodynamic therapy (SDT) paradigm to induce energy metabolism disorder and drug resistance change of DRTCs. A US-controlled "Nanoenabled Energy Metabolism Jammer" (TL@HPN) is designed using perfluoropentane (PFP) adsorbing oxygen in the core, and a targeting peptide (CGNKRTR) is attached to the liposome as the delivery carrier shell to incorporate hematoporphyrin monomethyl ether (HMME) and paclitaxel (PTX). The TL@HPN with ultrasonic/photoacoustic imaging (PAI/USI) precisely controlled the release of drugs and oxygen after being triggered by ultrasound (US), which attenuated the hypoxic microenvironment. SDT boosted the reactive oxygen species (ROS) content in tumor tissues, preferentially inducing mitochondrial apoptosis and maximizing immunogenic cell death (ICD). Persistently elevated oxidative stress levels inhibited ATP production and downregulated P-gp expression by disrupting the redox balance and electron transfer of the respiratory chain. We varied the effect of TL@HPN combined with PD-1/PD-L1 to activate autoimmunity and inhibit tumor metastasis, providing a practical strategy for expanding the use of SDT-mediated tumor energy metabolism.

Polymer- and lipid-based gene delivery technology for CAR T cell therapy

Chimeric antigen receptor T cell (CAR T cell) therapy is a revolutionary approach approved by the FDA and EMA to treat B cell malignancies and multiple myeloma. The production of these T cells has been done through viral vectors, which come with safety concerns, high cost and production challenges, and more recently also through electroporation, which can be extremely cytotoxic. In this context, nanosystems can constitute an alternative to overcome the challenges associated with current methods, resulting in a safe and cost-effective platform. However, the barriers associated with T cells transfection show that the design and engineering of novel approaches in this field are highly imperative. Here, we present an overview from CAR constitution to transfection technologies used in T cells, highlighting the lipid- and polymer-based nanoparticles as a potential delivery platform. Specifically, we provide examples, strengths and weaknesses of nanosystem formulations, and advances in nanoparticle design to improve transfection of T cells. This review will guide the researchers in the design and development of novel nanosystems for next-generation CAR T therapeutics.

Drug Resistance: The Role of Exosomal miRNA in the Microenvironment of Hematopoietic Tumors

Extracellular vesicles (EVs), including exosomes, have an important role thanks to their ability to communicate and exchange information between tumor cells and the tumor microenvironment (TME), and have also been associated with communicating anti-cancer drug resistance (DR). The increase in proliferation of cancer cells alters oxygen levels, which causes hypoxia and results in a release of exosomes by the cancer cells. In this review, the results of studies examining the role of exosomal miRNA in DR, and their mechanism, are discussed in detail in hematological tumors: leukemia, lymphoma, and multiple myeloma. In conclusion, we underline the exosome's function as a possible drug delivery vehicle by understanding its cargo. Engineered exosomes can be used to be more specific for personalized therapy.

Tumor microenvironment penetrating chitosan nanoparticles for elimination of cancer relapse and minimal residual disease

Chitosan and its derivatives are among biomaterials with numerous medical applications, especially in cancer. Chitosan is amenable to forming innumerable shapes such as micelles, niosomes, hydrogels, nanoparticles, and scaffolds, among others. Chitosan derivatives can also bring unprecedented potential to cross numerous biological barriers. Combined with other biomaterials, hybrid and multitasking chitosan-based systems can be realized for many applications. These include controlled drug release, targeted drug delivery, post-surgery implants (immunovaccines), theranostics, biosensing of tumor-derived circulating materials, multimodal systems, and combination therapy platforms with the potential to eliminate bulk tumors as well as lingering tumor cells to treat minimal residual disease (MRD) and recurrent cancer. We first introduce different formats, derivatives, and properties of chitosan. Next, given the barriers to therapeutic efficacy in solid tumors, we review advanced formulations of chitosan modules as efficient drug delivery systems to overcome tumor heterogeneity, multi-drug resistance, MRD, and metastasis. Finally, we discuss chitosan NPs for clinical translation and treatment of recurrent cancer and their future perspective.

Vinegar-baked Radix Bupleuri enhances the liver-targeting effect of rhein on liver injury rats by regulating transporters

OBJECTIVE

This study aimed to explore whether the liver-targeting enhancing effect of vinegar-baked Radix Bupleuri (VBRB) on rhein was achieved by affecting transporters, metabolism enzymes as well as hepatocyte nuclear factor 1α/4α (HNF1α/HNF4α) in liver injury.

METHODS

The effect of VBRB on the efficacy of rhein was performed with the LPS-induced acute liver injury rat model. Aspartate aminotransferase (AST), alanine transaminase (ALT) and superoxide dismutase (SOD) levels were determined and histopathological examination was taken. Drug concentrations in tissues were determined by high performance liquid chromatography (HPLC). The protein expressions of drug transporters, metabolic enzymes and hepatic nuclear factors were determined by Western blotting and ELISA assays.

KEY FINDING

VBRB improved the liver protecting effect of rhein, which was consistent with its promoting effect on targeted enrichment of rhein in the liver. VBRB or in combination with rhein inhibited P-glycoprotein (Pgp) and multi-resistance related protein 2 (MRP2), while increased organic anion transporting polypeptide 2 (OATP2), which might be the reason why VBRB promoted liver-targeting effect of rhein.

CONCLUSION

VBRB enhances the liver-protecting effect of rhein by down-regulating Pgp, MRP2, and up-regulating OATP2.

Recent Advances in Glioma Cancer Treatment: Conventional and Epigenetic Realms

Glioblastoma (GBM) is the most typical and aggressive form of primary brain tumor in adults, with a poor prognosis. Successful glioma treatment is hampered by ineffective medication distribution across the blood-brain barrier (BBB) and the emergence of drug resistance. Although a few FDA-approved multimodal treatments are available for glioblastoma, most patients still have poor prognoses. Targeting epigenetic variables, immunotherapy, gene therapy, and different vaccine- and peptide-based treatments are some innovative approaches to improve anti-glioma treatment efficacy. Following the identification of lymphatics in the central nervous system, immunotherapy offers a potential method with the potency to permeate the blood-brain barrier. This review will discuss the rationale, tactics, benefits, and drawbacks of current glioma therapy options in clinical and preclinical investigations.

In vivo computation with sensor fusion and search acceleration for smart tumor homing

BACKGROUND AND OBJECTIVE

Motivated by the advancements on bioresorbable nanoswimmers, this paper considers the advantages of direct targeting over systemic targeting for smart tumor homing under the general framework of computational nanobiosensing. Nanoswimmers assembled by magnetic nanoparticles can be used as contrast agents to estimate the locations of tumors inside the human body.

METHODS

Closely observing the response of nanoswimmers (which act as in vivo biosensors) to the tumor-triggered biological gradients and then guiding them through external manipulation, can result in a higher accumulation at the diseased location. Sensor informatics along with data fusion can play a crucial role in such a knowledge-aided targeting process. Specifically, built upon our previous work on direct targeting inspired by the gradient descent optimization, this work is focused on resolving the real-life constraints of in vivo natural computation such as uniformity of the magnetic field and finite life span of the nanoswimmers. To overcome these challenges, we propose a multi-estimate-fusion strategy to obtain a common steering direction for the swarm of nanoswimmers.

RESULTS

We show through computational experiments (1) that the mean of individual gradient estimations provides the best choice for symmetrical conditions (tumor location in line with the direction of blood flow) while leader-based swarm steering gives the best results for non-symmetrical search space, and (2) that the iterative memory-driven gradient descent optimization detects the target faster compared to the classical memory-less gradient descent and knowledge-less systemic targeting.

CONCLUSION

Our proposed strategies demonstrate that a clear demarcation between malignant tumors and healthy tissues can be visualized before nanoswimmers are consumed in human vasculature. We believe that our work will help in overcoming the challenges posed by natural in vivo computation for tumor diagnosis at its early stage.

Evaluation of thermosensitive chitosan hydrogel containing gefitinib loaded cellulose acetate butyrate nanoparticles in a subcutaneous breast cancer model

In the present study, gefitinib loaded cellulose acetate butyrate nanoparticles (Gnb-NPs) were prepared and then incorporated into thermo-sensitive chitosan/β-glycerophosphate hydrogels for intratumoral administration in mice bearing breast cancer. Accordingly, Gnb-NPs were prepared using the solvent evaporation process and optimized by applying a two-level fractional factorial design. Properties of NPs, including particle size, zeta potential (ZP), polydispersity index (PdI), encapsulation efficiency (EE) % and drug loading (DL) %, were investigated; the optimized Gnb-NPs were then loaded in chitosan hydrogels (Gnb-NPs-Hydrogel). The formulated Gnb-NPs-Hydrogel was assessed in terms of gelling time, release behavior, injectability, swelling and degradation behavior. The anti-cancer efficacy of Gnb-NPs-Hydrogel was evaluated in vitro against the 4 T1 breast cancer cell line and in vivo in breast tumor bearing mice. The optimized formulation showed spherical particles with the size of 156.50 ± 2.40 nm, PdI of 0.20 ± 0.002, ZP of -4.90 ± 0.04 mV, EE of 99.77 ± 0.09 % and DL of 20.59 ± 0.05 %. Incorporating Gnb-NPs into the hydrogel led to the decrease of the drug release rate. Gnb-NPs-Hydrogel displayed a greater cytotoxic effect in comparison to the free Gnb and Gnb-Hydrogel in 4 T1 cancer cells. Furthermore,intratumorallyinjectedGnb-NPs-Hydrogel showed the strongest antitumor efficacy in vivo. The superior performance of Gnb-NPs-Hydrogel, thus, demonstrated its potential for the treatment of breast cancer.

Recent advances in targeted drug delivery systems for resistant colorectal cancer

Colorectal cancer (CRC) is one of the deadliest cancers in the world, the incidences and morality rate are rising and poses an important threat to the public health. It is known that multiple drug resistance (MDR) is one of the major obstacles in CRC treatment. Tumor microenvironment plus genomic instability, tumor derived exosomes (TDE), cancer stem cells (CSCs), circulating tumor cells (CTCs), cell-free DNA (cfDNA), as well as cellular signaling pathways are important issues regarding resistance. Since non-targeted therapy causes toxicity, diverse side effects, and undesired efficacy, targeted therapy with contribution of various carriers has been developed to address the mentioned shortcomings. In this paper the underlying causes of MDR and then various targeting strategies including exosomes, liposomes, hydrogels, cell-based carriers and theranostics which are utilized to overcome therapeutic resistance will be described. We also discuss implication of emerging approaches involving single cell approaches and computer-aided drug delivery with high potential for meeting CRC medical needs.

Multifunctional Nanosystems Powered Photodynamic Immunotherapy

Photodynamic Therapy (PDT) with the intrinsic advantages including non-invasiveness, spatiotemporal selectivity, low side-effects, and immune activation ability has been clinically approved for the treatment of head and neck cancer, esophageal cancer, pancreatic cancer, prostate cancer, and esophageal squamous cell carcinoma. Nevertheless, the PDT is only a strategy for local control of primary tumor, that it is hard to remove the residual tumor cells and inhibit the tumor metastasis. Recently, various smart nanomedicine-based strategies are developed to overcome the barriers of traditional PDT including the drawbacks of traditional photosensitizers, limited tissue penetrability of light, inefficient induction of tumor cell death and tumor resistance to the therapy. More notably, a growing number of studies have focused on improving the therapeutic efficiency by eliciting host immune system with versatile nanoplatforms, which heralds a broader clinical application prospect of PDT in the future. Herein, the pathways of PDT induced-tumor destruction, especially the host immune response is summarized, and focusing on the recent progress of nanosystems-enhanced PDT through eliciting innate immunity and adaptive immunity. We expect it will provide some insights for conquering the drawbacks current PDT and expand the range of clinical application through this review.

Targeted nanomedicine in cisplatin-based cancer therapeutics

Since its license in 1978, cisplatin has proved to be one of the most successful chemotherapeutic agents in the world. However, two acute challenges facing cisplatin, resistance and toxicity, have resulted in a bottleneck of clinical application. Targeted nanomedicine shows great promise in delivering cisplatin for maximizing efficacy while minimizing off-target toxicity. This article surveyed the recent progress and challenges of targeted nanomedicine in managing resistance and toxicity of cisplatin in both fundamental and clinical aspects. Particularly, we focused on three major mechanisms counteracting cisplatin sensitivity (decreased intracellular accumulation, increased cisplatin deactivation, and enhanced DNA repair/translesion synthesis) and correspondingly highlighted a few representative approaches to increase cisplatin sensitivity through improving the intracellular concentration of cisplatin and implementing combination therapy. Moreover, the requirements for future advancements in cisplatin delivery systems are rendered with emphasis on (i) understanding of nano-bio interaction and post-accumulation biological effects instead of overwhelmingly improving tumor accumulation, (ii) development of stimuli-responsive and/or actively-targeted nanomedicines, (iii) optimization of combination therapy, (iv) novel combinations targeting tumor microenvironment and immunotherapy. We postulate that cisplatin-based nanomedicines will continuously advance and potentially revolutionize oncological treatment.

Homing peptide combined with DNAzyme-based ELISA-like assay for highly specific and sensitive detection of fibrin

A highly sensitive and specific ELISA-like chemiluminescence method for detection of fibrin has been developed. In the sensing platform, the homing peptide (CREKA), as recognition molecule, which can specially recognize the fibrin on microtiter plate, combined with G-quadruplex-based DNAzyme to form the probe of G-quadruplex-hemin DNAzyme-CREKA. After the sample solution was coated on the plates, the probe was crosslinked with fibrin through the interaction of CREKA and fibrin. Finally, luminol-H₂O₂ chemiluminesecence (CL) reaction was exploited for quantitative analysis of fibrin. The liner range for fibrin detection was from 0.112 pmol L^-1 to 5.6 pmol L^-1 with the detection limit of fibrin as low as 0.04 pmol L^-1, based on a signal-to-noise ratio (S/N) of 3. Furthermore, on the basis of the high amplification efficiency of the rolling circle amplification (RCA) reaction, the method enabled to analyze fibrin with a detection limit corresponding to 0.06 fmol L^-1, whose sensitivity increased 3 orders of magnitude than that of above method in the absence of RCA reaction. In particular, combined with the separation and washing steps of ELISA, the proposed method possessed higher selectivity, high-throughput and low cost, which shows promise for applications in clinical diagnosis.

Polyethylenimine grafted-chitosan based Gambogic acid copolymers for targeting cancer cells overexpressing transferrin receptors

Recent advancements in gene delivery systems that specifically target a variety of cancer types have increased demand for tissue-specific gene therapy. The current study describes the synthesis of a copolymer (GPgWSC) composed of a polyethylenimine (PEI)-grafted water-soluble chitosan (WSC) and gambogic acid (GA). It was validated as a ligand capable of enabling targeted attachment to transferrin receptors in HCT116 cancer cell lines. GPgWSC demonstrated superior antitumor activity in vitro in HCT116 compared to LoVo or MCF-7 cell lines, facilitated by the apoptotic activity of psiRNA-hBCL2. Pre-incubation of transferrin significantly inhibited GFP expression in the GPgWSC polyplex, demonstrating that GA is an extremely effective transferrin receptor targeting molecule. Additionally, in the HCT116-bearing mouse model, the tumor mass of PBS-treated mice increased to 2270 mm² after 22 days, but the injection of GPgWSC polyplex significantly reduced the mass-increasing rate as a mass size of 248 mm².

MOF-Mediated Synthesis of CuO/CeO2 Composite Nanoparticles: Characterization and Estimation of the Cellular Toxicity against Breast Cancer Cell Line (MCF-7)

A copper oxide/cerium oxide nanocomposite (CuO/CeO₂, NC) was synthesized via a novel method using a metal–organic framework as a precursor. This nanomaterial was characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), dynamic light scattering size analysis (DLS), and zeta potential. The PXRD showed the successful synthesis of the CuO/CeO₂ NC, in which the 2theta values of 35.55° (d = 2.52 Å, 100%) and 38.73° (d = 2.32 Å, 96%) revealed the existence of copper (II) oxide. FTIR analysis showed the CeO₂, hydroxyl groups, absorbed water, and some residual peaks. The solid phase analysis by FESEM and TEM images showed mean particle sizes of 49.18 ± 24.50 nm and 30.58 ± 26.40 nm, respectively, which were comparable with crystallite size (38.4 nm) obtained from PXRD, but it appears the CuO/CeO₂ NC was not evenly distributed and in some areas, showed it was highly agglomerated. The hydrodynamic size (750.5 nm) also showed the agglomeration of the CuO/CeO₂ NCs in the solution, which had a negatively charged surface. The CuO/CeO₂ NCs showed anti-proliferative activity against human breast cancer cell line (MCF-7) in a dose- and time-dependence way, while affecting normal cells less significantly.

Photodynamic Therapy and Hyperthermia in Combination Treatment-Neglected Forces in the Fight against Cancer

Cancer is one of the leading causes of death in humans. Despite the progress in cancer treatment, and an increase in the effectiveness of diagnostic methods, cancer is still highly lethal and very difficult to treat in many cases. Combination therapy, in the context of cancer treatment, seems to be a promising option that may allow minimizing treatment side effects and may have a significant impact on the cure. It may also increase the effectiveness of anti-cancer therapies. Moreover, combination treatment can significantly increase delivery of drugs to cancerous tissues. Photodynamic therapy and hyperthermia seem to be ideal examples that prove the effectiveness of combination therapy. These two kinds of therapy can kill cancer cells through different mechanisms and activate various signaling pathways. Both PDT and hyperthermia play significant roles in the perfusion of a tumor and the network of blood vessels wrapped around it. The main goal of combination therapy is to combine separate mechanisms of action that will make cancer cells more sensitive to a given therapeutic agent. Such an approach in treatment may contribute toward increasing its effectiveness, optimizing the cancer treatment process in the future.

ROS-Responsive and active targeted drug delivery based on conjugated polymer nanoparticles for synergistic chemo-/photodynamic therapy

Stimuli-responsive and active targeted drug release is highly significant and challenging for precise and effective cancer therapy. Herein, a reactive oxygen species (ROS)-responsive drug delivery system iRGD-BDOX@CPNs with active targeting for chemo-/photodynamic (PDT) synergistic therapy has been reported. This nanocarrier iRGD-BDOX@CPNs is constructed by the self-assembly of conjugated polymer poly(fluorene-co-vinylene) (PFV), prodrug BDOX (doxorubicin modified with a phenylboronic acid ester group) and an amphiphilic polymer (DSPE-PEG) modified with internalized RGD (DSPE-PEG-iRGD). The hydrophobic inner cores formed by PFV main chains tightly enclose BDOX. Due to PFV generating many ROS by light triggering, the BDOX prodrug can be in situ activated, resulting in the highly efficient drug release. In addition, the remarkable fluorescence recovery could be used for real-time monitoring of drug delivery and guiding antitumor therapy. Contributing to the specific recognition between iRGD and integrin αvβ3 receptors over-expressed on the surface of tumor cells, the active targeting and uptake of iRGD-BDOX@CPNs in tumor cells are greatly enhanced. The prominent anti-cancer effect of iRGD-BDOX@CPNs is realized by targeted drug delivery and synergistic therapeutic effects of PDT/chemotherapy. This study illustrates that the development of ROS-responsive and targeted drug delivery nanocarriers iRGD-BDOX@CPNs provides a new insight for controllable drug release and tumor precision therapy.

Nanoparticles and bioorthogonal chemistry joining forces for improved biomedical applications

Bioorthogonal chemistry comprises chemical reactions that can take place inside complex biological environments, providing outstanding tools for the investigation and elucidation of biological processes. Its use in combination with nanotechnology can lead to further developments in diverse areas of biomedicine, such as molecular bioimaging, targeted delivery, in situ drug activation, study of cell-nanomaterial interactions, biosensing, etc. Here, we summarise the recent efforts to bring together the unique properties of nanoparticles and the remarkable features of bioorthogonal reactions to create a toolbox of new or improved biomedical applications. We show how, by joining forces, bioorthogonal chemistry and nanotechnology can overcome some of the key current limitations in the field of nanomedicine, providing better, faster and more sensitive nanoparticle-based bioimaging and biosensing techniques, as well as therapeutic nanoplatforms with superior efficacy.

Single- versus Dual-Targeted Nanoparticles with Folic Acid and Biotin for Anticancer Drug Delivery

Cancer is one of the major causes of death worldwide and its treatment remains very challenging. The effectiveness of cancer therapy significantly depends upon tumour-specific delivery of the drug. Nanoparticle drug delivery systems have been developed to avoid the side effects of the conventional chemotherapy. However, according to the most recent recommendations, future nanomedicine should be focused mainly on active targeting of nanocarriers based on ligand-receptor recognition, which may show better efficacy than passive targeting in human cancer therapy. Nevertheless, the efficacy of single-ligand nanomedicines is still limited due to the complexity of the tumour microenvironment. Thus, the NPs are improved toward an additional functionality, e.g., pH-sensitivity (advanced single-targeted NPs). Moreover, dual-targeted nanoparticles which contain two different types of targeting agents on the same drug delivery system are developed. The advanced single-targeted NPs and dual-targeted nanocarriers present superior properties related to cell selectivity, cellular uptake and cytotoxicity toward cancer cells than conventional drug, non-targeted systems and single-targeted systems without additional functionality. Folic acid and biotin are used as targeting ligands for cancer chemotherapy, since they are available, inexpensive, nontoxic, nonimmunogenic and easy to modify. These ligands are used in both, single- and dual-targeted systems although the latter are still a novel approach. This review presents the recent achievements in the development of single- or dual-targeted nanoparticles for anticancer drug delivery.

Dual ultrasound-activatable nanodroplets for highly-penetrative and efficient ovarian cancer theranostics

The selective delivery and deep intertumoral penetration of nanosensitizers remain challenging in the fabrication of sonodynamic therapy (SDT) platforms. In this work, we rationally constructed dual ultrasound (US)-activatable nanodroplets (NDs)/nanoliposomes/nanosensitizers with perfluoropentane (PFP) in the core, hematoporphyrin monomethyl ether (HMME) in the phospholipid shell and folate (FA)-conjugated to the surface (collectively termed FA-H@NDs). We aimed to validate the feasibility of these FA-H@NDs for FA receptor (FR)-overexpressed ovarian cancer theranostics. The ND formulations were based on PFP that can undergo acoustic droplet vaporization (ADV) when exposed to US irradiation. The ADV phenomenon disrupts the adjacent vasculature, and the resistance to drug diffusion within the tumor can be decreased, enabling nanosensitizers to more deeply penetrate into the inner tissue far from the intertumoral vasculature. These FA-H@NDs assisted by US irradiation can also induce the production of excess reactive oxygen species (ROS) and consequently trigger tumor cell/tissue apoptosis and necrosis. Furthermore, this therapeutic process can be guided and monitored by US/photoacoustic (PA) dual-modal imaging. This work established a new paradigm for highly efficient ovarian cancer theranostics based on the rational utilization of dual US-activatable NDs.

Recent applications and strategies in nanotechnology for lung diseases

Lung diseases, including COVID-19 and lung cancers, is a huge threat to human health. However, for the treatment and diagnosis of various lung diseases, such as pneumonia, asthma, cancer, and pulmonary tuberculosis, are becoming increasingly challenging. Currently, several types of treatments and/or diagnostic methods are used to treat lung diseases; however, the occurrence of adverse reactions to chemotherapy, drug-resistant bacteria, side effects that can be significantly toxic, and poor drug delivery necessitates the development of more promising treatments. Nanotechnology, as an emerging technology, has been extensively studied in medicine. Several studies have shown that nano-delivery systems can significantly enhance the targeting of drug delivery. When compared to traditional delivery methods, several nanoparticle delivery strategies are used to improve the detection methods and drug treatment efficacy. Transporting nanoparticles to the lungs, loading appropriate therapeutic drugs, and the incorporation of intelligent functions to overcome various lung barriers have broad prospects as they can aid in locating target tissues and can enhance the therapeutic effect while minimizing systemic side effects. In addition, as a new and highly contagious respiratory infection disease, COVID-19 is spreading worldwide. However, there is no specific drug for COVID-19. Clinical trials are being conducted in several countries to develop antiviral drugs or vaccines. In recent years, nanotechnology has provided a feasible platform for improving the diagnosis and treatment of diseases, nanotechnology-based strategies may have broad prospects in the diagnosis and treatment of COVID-19. This article reviews the latest developments in nanotechnology drug delivery strategies in the lungs in recent years and studies the clinical application value of nanomedicine in the drug delivery strategy pertaining to the lung.

Chemo-physical Strategies to Advance the in Vivo Functionality of Targeted Nanomedicine: The Next Generation

The past few decades have witnessed an evolution of nanomedicine from biologically inert entities to more smart systems, aimed at advancing in vivo functionality. However, we should recognize that most systems still rely on reasonable explanation-including some over-explanation-rather than definitive evidence, which is a watershed radically determining the speed and extent of advancing nanomedicine. Probing nano-bio interactions and desirable functionality at the tissue, cellular, and molecular levels is most frequently overlooked. Progress toward answering these questions will provide instructive insight guiding more effective chemo-physical strategies. Thus, in the next generation, we argue that much effort should be made to provide definitive evidence for proof-of-mechanism, in lieu of creating many new and complicated systems for similar proof-of-concept.

Endocrine-Disrupting Chemicals' (EDCs) Effects on Tumour Microenvironment and Cancer Progression: Emerging Contribution of RACK1

Endocrine disruptors (EDCs) can display estrogenic and androgenic effects, and their exposure has been linked to increased cancer risk. EDCs have been shown to directly affect cancer cell regulation and progression, but their influence on tumour microenvironment is still not completely elucidated. In this context, the signalling hub protein RACK1 (Receptor for Activated C Kinase 1) could represent a nexus between cancer and the immune system due to its roles in cancer progression and innate immune activation. Since RACK1 is a relevant EDCs target that responds to steroid-active compounds, it could be considered a molecular bridge between the endocrine-regulated tumour microenvironment and the innate immune system. We provide an analysis of immunomodulatory and cancer-promoting effects of different EDCs in shaping tumour microenvironment, with a final focus on the scaffold protein RACK1 as a pivotal molecular player due to its dual role in immune and cancer contexts.

Construction of a tumor microenvironment pH-responsive cleavable PEGylated hyaluronic acid nano-drug delivery system for colorectal cancer treatment

In order to improve active tumor targeting, tumor cell uptake efficiency and circulation time of doxorubicin (DOX) in vivo, we constructed a cleavable PEGylated hyaluronic acid nano-drug delivery system (HA-mPEG2k-DOX) based on a tumor microenvironment pH-responsive imine bond. In this study, HA-mPEG2k-DOX can self-assemble into stable nanoparticles (HA-mPEG2k-DOX NPs) with a particle size of 50 nm. And the NPs can efficiently target CD44 positive CT26 cells and the pH-responsive cleavable PEG shell can be detached under weakly acidic environments and effectively promote the cellular uptake of HA-DOX NPs. Compared with DOX·HCl, the HA-mPEG2k-DOX NPs can significantly increase the DOX circulation time by 12.5 times, efficiently target the tumor tissues of CT26 tumor-bearing mice and remain for 72 hours. Therefore, the antitumor results in vivo indicated that the HA-mPEG2k-DOX NPs have the best anti-tumor effect while reducing the toxicity of the DOX. Overall, the cleavable PEGylated HA-mPEG2k-DOX NPs responding to pH-sensitive imine bonds, while actively targeting CD44-positive tumor cells, improve the dilemma of cellular uptake and delivery by the PEGylated nano delivery system.

Nanoplatform-based cascade engineering for cancer therapy

Various therapeutic techniques have been studied for treating cancer precisely and effectively, such as targeted drug delivery, phototherapy, tumor-specific catalytic therapy, and synergistic therapy, which, however, evoke numerous challenges due to the inherent limitations of these therapeutic modalities and intricate biological circumstances as well. With the remarkable advances of nanotechnology, nanoplatform-based cascade engineering, as an efficient and booming strategy, has been tactfully introduced to optimize these cancer therapies. Based on the designed nanoplatforms, pre-supposed cascade processes could be triggered under specific conditions to generate/deliver more therapeutic species or produce stronger tumoricidal effects inside tumors, aiming to achieve cancer therapy with increased anti-tumor efficacy and diminished side effects. In this review, the recent advances in nanoplatform-based cascade engineering for cancer therapy are summarized and discussed, with an emphasis on the design of smart nanoplatforms with unique structures, compositions and properties, and the implementation of specific cascade processes by means of endogenous tumor microenvironment (TME) resources and/or exogenous energy inputs. This fascinating strategy presents unprecedented potential in the enhancement of cancer therapies, and offers better controllability, specificity and effectiveness of therapeutic functions compared to the corresponding single components/functions. In the end, challenges and prospects of such a burgeoning strategy in the field of cancer therapy will be discussed, hopefully to facilitate its further development to meet the personalized treatment demands.

Alginate-Based Platforms for Cancer-Targeted Drug Delivery

As an acidic, ocean colloid polysaccharide, alginate is both a biopolymer and a polyelectrolyte that is considered to be biocompatible, nontoxic, nonimmunogenic, and biodegradable. A significant number of studies have confirmed the potential use of alginate-based platforms as effective vehicles for drug delivery for cancer-targeted treatment. In this review, the focus is on the formation of alginate-based cancer-targeted delivery systems. Specifically, some general chemical and physical properties of alginate and different types of alginate-based delivery systems are discussed, and various kinds of alginate-based carriers are introduced. Finally, recent innovative strategies to functionalize alginate-based vehicles for cancer targeting are described to highlight research towards the optimization of alginate.

Hyaluronic acid-shelled, peptide drug conjugate-cored nanomedicine for the treatment of hepatocellular carcinoma

Peptide-drug conjugate (PDC) is a promising prodrug in drug delivery systems. To fabricate nanostructures with proper molecular design which can self-assemble to spherical morphologies is very important for PDC chemotherapy. In this study, a novel PDC (PDC-DOX₂), in which two doxorubicin (DOX) molecules are conjugated onto a short peptide (KIGLFRWR) with self-assembly function, was designed and synthesized. PDC-DOX₂ with self-assembly properties forms a spherical structure under hydrophobic interaction in water. Hyaluronic acid (HA) was then coated on PDC-DOX₂ micelles to form a HA-shelled, peptide-doxorubicin conjugate-cored nanomedicine (HA@PDC-DOX₂). The amount of HA can regulate the particle size and stabilization of HA@PDC-DOX₂. In addition, HA can actively enhance the targeting effects of PDC-DOX₂ micelles since it can interact with overexpressed receptors in cancer cells. The core-shell structured HA@PDC-DOX₂ nanomedicine showed significantly enhanced potency against hepatocellular carcinoma compared to PDC-DOX₂ micelles as well as free DOX. In this work, a novel PDC which can self-assemble to spherical morphologies and a core-shell structure HA@PDC-DOX₂ nanomedicine are designed and prepared. It provides a convenient strategy for the size control of PDC assemblies and constructs effective PDC-based drug delivery systems for cancer treatment.

Development of long-circulating lapachol nanoparticles: formation, characterization, pharmacokinetics, distribution and cytotoxicity

Lapachol is an active compound for the treatment of malignant brain glioma. However, its physicochemical properties limit its clinical application. The purpose of this study is to develop a nano-drug delivery system (LPC-LP) loaded with lapachol (LPC), which remarkably prolongs the half-life in the body, and increases the brain intake, therefore, achieving a better anticancer effect in the treatment of glioma. In order to optimize the formulation of liposomes, an orthogonal design was adopted with entrapment efficiency (EE) as the index. The characterization of the optimized formulation was evaluated in vitro. To assess the safety profile and effect of LPC-LP, a rapid and sensitive ultra-fast liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed for studying the pharmacokinetics and brain distribution of LPC-LP and LPC. Finally, the cytotoxicity of the two preparations on C6 cells was studied by the MTT assay. The results showed that the average particle size of LPC-LP was 85.92 ± 2.35 nm, the EE of liposomes was 92.52 ± 1.81%, and the charge potential was −40.70 ± 9.20 mV. An in vitro release study showed that the release of lapachol from LPC-LP was delayed compared to LPC, indicating that LPC-LP was a sustained and controlled release system. The UPLC-MS/MS method was fully validated in both plasma and brain tissue according to the Food and Drug Administration (FDA) recommended guidelines, and successfully used for quantification of lapachol in vivo. After intravenous administration, LPC-LP prolonged circulation time of lapachol in the body and increased brain intake. Besides, the MTT results revealed that the IC₅₀ value of LPC-LP on C6 cells significantly decreased, compared with LPC, which further confirmed that LPC-LP enhanced the inhibition of C6 cells and improved the anti-glioma effect. In conclusion, LPC-LP could serve as a promising candidate for the clinical application of lapachol in the treatment of glioma.

LPC-LP is a promising and potential nanoparticle in the treatment of glioma.

Two-stage activated nano-truck enhanced specific aggregation and deep delivery for synergistic tumor ablation

Although nanomedicines have shown high performance in tumor theranostics, their anticancer activity is still limited by the drug delivery capacity, especially lack of targeting capability, poor tumor accumulation, and insufficient tumor deep-penetration. To address this challenge, a high biocompatibility nano-truck (BMP NT) with a two-stage delivery mechanism is designed and developed to achieve the precision therapeutic efficacy of cancer. In view of the enhanced permeability retention (EPR) effect, the surface cleavable layer of BMP NTs can be selectively removed by the overexpressed MMP-2 in a tumor-microenvironment to expose the hydrophobic segments for an induced "braking effect" strategy, resulting in a significant increase in tumor accumulation. Once internalized into cancer cells with the overproduced glutathione (GSH) and H₂O₂, the BMP NTs undergo the second-stage "unloading process" to release Mn²⁺ ions and ultrasmall Bi₂S₃@BSA nanoparticles, and the obtained Mn²⁺ ions can act as a Fenton-like catalyst for continuously catalyzing the endogenous H₂O₂ into highly toxic hydroxyl radicals (˙OH) for CDT. The GSH depletion will in turn improve the Mn²⁺-H₂O₂ reaction, further enhancing CDT efficiency. Meanwhile, the ultrasmall Bi₂S₃@BSA endows BMP NTs with excellent photothermal conversion ability to generate local hyperthermia and accelerate the intratumoral Fenton process, thus leading to an effective tumor therapeutic outcome in the synergistic function of CDT/photothermal therapy (PTT). Moreover, the BMP NTs can be used for in situ self-generation magnetic resonance imaging (MRI) and photoacoustic (PA) imaging to guide precision cancer therapy.

Doxorubicin-loading core-shell pectin nanocell: A novel nanovehicle for anticancer agent delivery with multidrug resistance reversal

Tumor is a prevalent great threat to public health worldwide and multidrug resistance (MDR) of tumor is a leading cause of chemotherapy failure. Nanomedicine has shown prospects in overcoming the problem. Doxorubicin (DOX), a broad-spectrum anticancer drug, showed limited efficacy due to MDR. Herein, a doxorubicin containing pectin nanocell (DOX-PEC-NC) of core-shell structure, a pectin nanoparticle encapsulated with liposome-like membrane was developed. The DOX-PEC-NC, spheroid in shape and sized around 150 nm, exerted better sustained release behavior than doxorubicin loading pectin nanoparticle (DOX-PEC-NP) or liposome (DOX-LIP). In vitro anticancer study showed marked accumulation of doxorubicin in different tumor cells as well as reversal of MDR in HepG2/ADR cells and MCF-7/ADR cells caused by treatment of DOX-PEC-NC. In H22 tumor-bearing mice, DOX-PEC-NC showed higher anticancer efficacy and lower toxicity than doxorubicin. DOX-PEC-NC can improve anticancer activity and reduce side effect of doxorubicin due to increased intracellular accumulation and reversal of MDR in tumor cells, which may be a promising nanoscale drug delivery vehicle for chemotherapeutic agents.

Magnetic stomatocyte-like nanomotor as photosensitizer carrier for photodynamic therapy based cancer treatment

Amphiphilic block copolymer can self-assemble to stomatocyte-like structure as drug delivery carrier. Photodynamic therapy (PDT) is an emerging modality for cancer treatment. However, PDT has various problems, such as weak tumor accumulation ability of photosensitizers (PSs), short lifetime of singlet oxygen (¹O₂, main reactive oxygen species in PDT) and tumor hypoxia microenvironment, to restrict its therapeutic efficacy. To convey PSs to tumor tissues and improve PDT efficacy, iron oxide nanoparticles (IONPs) were loaded inside the self-assembly stomatocytes-like structure of poly(ethylene glycol) block polystyrene (PEG-b-PS) as nanomotors (IONPs loaded stomatocytes nanomotors, denoted IS-NMs) for PS (zinc phthalocyanine, ZnPc) delivery. The hybrid nanomotors (iron oxide nanoparticles loaded stomatocytes@ZnPc nanomotors, denoted ISP-NMs) can be gathered in tumor tissues under magnetic field owing to magnetism of IONPs. After been trapped by cancer cells, IONPs can catalyze decomposition of endogenous H₂O₂ to generate O₂ as propelling force for ISP-NMs movement. The motion characteristics of ISP-NMs expanded the distribution of ZnPc to enlarge ROS reactive distribution and enhance the activity of PDT. And the generated O₂ can be supplied for PDT process to ensure its high-performance. Furthermore, ISP-NMs have nuclear magnetic resonance imaging (MRI) function since IONPs are efficient T₂ contrast agent.