Response of pH-Sensitive Doxorubicin Nanoparticles on Complex Tumor Microenvironments by Tailoring Multiple Physicochemical Properties

Cell membrane camouflaged Cu-doped mesoporous polydopamine for combined CT/PTT/CDT synergistic treatment of breast cancer

Currently, traditional monotherapy for cancer often results in indiscriminate attacks on the body, leading to the emergence of new health problems. To confront these challenges, multimodal combination therapy has become necessary. However, how to develop new smart nanomaterials through green synthesis methods, delivering drugs while simultaneously synergizing multimodal combination therapies for tumor treatment, remains a topic of great significance. In this study, a biomimetic composite nanomaterial (RM-Cu/P) composed of mesoporous polydopamine (MPDA) as the core and red blood cell membranes (RBCMs) as the shell was synthesized as a drug carrier to deliver doxorubicin (DOX) while achieving synergistic chemotherapy, photothermal and chemodynamic therapy (CT/PTT/CDT). Herein, the nanoparticles were extensively characterized to examine their morphological characteristics, elemental composition, and drug-carrying capacity. Notably, the coating of RBCM reduced the toxicity of the RM-Cu/P@DOX nanoparticles, improved their targeting ability and prolonged their circulation time in vivo. The Cu-doped nanoparticles were capable of initiating a Fenton-like reaction to generate reactive oxygen species (ROS) for CDT, while the photothermal conversion efficiency (η) reached 45.20 % under NIR laser irradiation. Subsequently, the particles were examined by in vivo and in vitro experimental studies in cytotoxicity, cellular uptake, ROS levels, lysosomal escape, and mouse tumor model to evaluate their potential application in antitumor. Compared with monotherapy, the RM-Cu/P@DOX nanoparticles had multiple-stimulation response properties under redox, pH, and NIR, which exhibited the advantage of combined trimodal therapy, resulting in remarkable synergistic antitumor efficacy. In conclusion, this innovative platform exhibited promising applications in smart drug delivery and synergistic treatment of cancer.

Inflammatory responsive neutrophil-like membrane-based drug delivery system for post-surgical glioblastoma therapy

Surgical resection of glioblastoma (GBM) causes brain inflammation that activates and recruits neutrophils (NEs) to residual GBM tissues. NE-based drug delivery using inflammatory chemotaxis is promising for the post-surgical treatment of residual GBM, but its clinical application is limited by the short life span of NEs and lack of in vitro propagation methods. HL60 cells are a type of infinitely multiplying tumor cells that can be induced to differentiate into NE-like cells. We developed a novel NE-like membrane system (NM-PD) by coating NE-like membranes on the surface of poly (lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG)-based doxorubicin (DOX)-loaded core (PLGA-PEG-DOX, PD) for post-surgical residual GBM treatment. Cell adhesion proteins were detected on NE-like membranes and endowed NM-PDs with inflammatory chemotaxis similar to mature NEs. The resulting NM-PD shows excellent inflamed in vitro blood-brain barrier (BBB) permeability and anti-proliferative effects on GBM cells. In our intracranial GBM resection model, NM-PD exhibited superior inflammatory chemotaxis and targeted residual GBM cells, thus remarkably improving antitumor capability and prolonging the survival time of the mice. These data suggest that NM-PD, which has sufficient sources and is easy to prepare, can efficiently suppress post-surgical residual GBM and holds potential for clinical transformation in GBM post-surgical adjuvant therapy.

Peptide-functionalized therapeutic nanoplatform for treatment orthotopic triple negative breast cancer and bone metastasis

Epidermal Growth Factor Receptor (EGFR) is a promising therapeutic target for triple-negative breast cancer (TNBC). Recently, specific EGFR-targeting peptide GE11-based delivery nano-system shows excellent potential because of its chemical versatility and good targeting ability. However, no further research focusing on the downstream of EGFR after binding with GE11 was explored. Hence, we tailor-designed a self-assembled nanoplatform named GENP using amphiphilic molecule of stearic acid-modified GE11. After loading doxorubicin (DOX), the resulted nanoplatform GENP@DOX demonstrated high loading efficiency and sustainable drug release. Importantly, our findings proved that GENP alone significantly suppressed the proliferation of MDA-MB-231 cells via EGFR-downstream PI3K/AKT signaling pathways, contributing to the synergistic treatment with its DOX release. Further work illustrated remarkable therapeutic efficacy both in orthotopic TNBC and its bone metastasis models with minimal biotoxicity. Together, the results highlight that our GENP-functionalized nanoplatform is a promising strategy for the synergistic therapeutic efficacy targeting EGFR-overexpressed cancer.

Preoperative administration of a biomimetic platelet nanodrug enhances postoperative drug delivery by bypassing thrombus

The postoperative thrombus attached to the damaged blood vessels severely obstructs drugs from crossing the damaged blood-brain barrier (BBB) and targeting residual glioma cells around surgical margins, leading to glioblastoma (GBM) recurrence. A thrombus-bypassing, BBB-crossing, and surgical margin-targeted nanodrug is needed to address this phenomenon. Encouraged by the intrinsic damaged vascular endothelium chemotaxis of platelets, a platelet membrane-coated nanodrug (PM-HDOX) delivering doxorubicin (DOX) for postoperative GBM treatment is proposed and systematically investigated. Because surgery damages the vascular endothelium on the BBB around the surgical margin, the platelet membrane coating endows PM-HDOX with its inherent capacity to cross the broken BBB and target the surgical margin. Moreover, preoperative administration combined with fast-targeted PM-HDOX can realize the potential of bypassing thrombus. In GBM resection models, PM-HDOX with preoperative administration demonstrated significantly enhanced BBB-crossing and surgical margin-targeted efficacy. In particular, the PM-HDOX intensities around the surgical margins of the preoperative administration group were more than twice that of the postoperative administration group due to bypassing the thrombus formed in the broken BBB. In the antitumor experiment, the preoperative administration of PM-HDOX significantly inhibited the growth of postoperative residual tumors and prolonged the median survival time of mice. In conclusion, preoperative administration of a biomimetic platelet nanodrug can be an efficient and promising drug delivery strategy for residual GBM after surgery.

A novel manganese dioxide-based drug delivery strategy via in situ coating γ-polyglutamic acid/cisplatin for intelligent anticancer therapy

Cisplatin (CDDP) is one of the most frequently used chemotherapeutic drugs due to its broad-spectrum and potent antitumor activity. Unfortunately, inactivation due to glutathione (GSH) substances and insufficient cellular uptake of CDDP greatly hinder its clinical applications. Herein, manganese dioxide (MnO₂) was reported as an efficient glutathione (GSH) consumption material for promoting the accumulation and preventing premature leakage of CDDP in tumor cells. In this work, γ-polyglutamic acid/cisplatin (PGA/CDDP) conjugates and PGA/CDDP nanoparticles (NPs) were respectively constructed via the ligand exchange reaction and electrostatic interaction. Furthermore, PGA/CDDP NPs were in situ coated with MnO₂ (PGA/CDDP@MnO₂ NPs) through the redox reaction of the residual carboxyl group (-COOH) and potassium permanganate (KMnO₄). As a result, the PGA/CDDP@MnO₂ NPs achieved a satisfactory drug-loading efficiency (ca. 37.26%) and multi-responsive controlled drug release. Remarkably, the MnO₂ shells exhibited excellent performance for efficient glutathione (GSH) consumption and significantly enhanced the killing effect (ca. 2-3 times) in human lung cancer cells (A549) compared with pure CDDP. Moreover, it was observed that PGA/CDDP@MnO₂ NPs could also inhibit the migration and invasion of A549 cells. Overall, these remarkable performances of PGA/CDDP@MnO₂ NPs make MnO₂ promising for controlled drug release and intelligent anticancer therapy.

Glioma diagnosis and therapy: Current challenges and nanomaterial-based solutions

Glioma is often referred to as one of the most dreadful central nervous system (CNS)-specific tumors with rapidly-proliferating cancerous glial cells, accounting for nearly half of the brain tumors at an annual incidence rate of 30-80 per a million population. Although glioma treatment remains a significant challenge for researchers and clinicians, the rapid development of nanomedicine provides tremendous opportunities for long-term glioma therapy. However, several obstacles impede the development of novel therapeutics, such as the very tight blood-brain barrier (BBB), undesirable hypoxia, and complex tumor microenvironment (TME). Several efforts have been dedicated to exploring various nanoformulations for improving BBB permeation and precise tumor ablation to address these challenges. Initially, this article briefly introduces glioma classification and various pathogenic factors. Further, currently available therapeutic approaches are illustrated in detail, including traditional chemotherapy, radiotherapy, and surgical practices. Then, different innovative treatment strategies, such as tumor-treating fields, gene therapy, immunotherapy, and phototherapy, are emphasized. In conclusion, we summarize the article with interesting perspectives, providing suggestions for future glioma diagnosis and therapy improvement.

Oxaliplatin delivery via chitosan/vitamin E conjugate micelles for improved efficacy and MDR-reversal in breast cancer

A bioinspired chitosan/vitamin E conjugate (Ch/VES, 1:4) was synthesized, optimized based on chitosan's molecular weight (15, 300 kDa), and was assembled to entrap oxaliplatin (OXPt). 1H NMR, infrared spectroscopy, chromatography, X-ray photoelectron spectroscopy, X-ray diffraction, drug release, hemolysis, and stability studies were performed to characterize OXPt@Ch/VES micelles. The therapeutic efficacy of the micelles was tested in vitro in ER+/PR+/HER2- and triple-negative sensitive/resistant breast cancer cells, MCF-7 and MDA-MB-231 via cellular uptake, cytotoxicity, nuclear staining, DNA fragmentation, mitochondrial membrane potential, ROS generation, apoptosis, and cell cycle assays and in vivo using 4T1(Luc)-tumor-bearing mice. OXPt@Ch/VES Ms exhibited decreased IC50 towards MCF-7, MDA-MB-231 (sensitive/resistant) than OXPt. OXPt@Ch/VES Ms caused extensive DNA damage, mitochondrial depolarization, apoptosis, and cell-growth arrest (G2/M). OXPt@Ch/VES Ms treatment retarded tumor growth significantly, prolonged survival, and decreased nephrotoxicity than OXPt. The OXPt@Ch/VES Ms could serve as a potential nanomedicine to overcome conventional OXPt-mediated drug resistance/nephrotoxicity in breast cancer.

Zwitterionic choline phosphate conjugated folate-poly (ethylene glycol): a general decoration of erythrocyte membrane-coated nanoparticles for enhanced tumor-targeting drug delivery

Erythrocyte membrane nanosystems have become one of the important research directions of disease treatment, especially for tumor treatment, and can enhance the long circulation time of anti-cancer drugs in vivo, and penetrate and accumulate in the tumor site effectively. However, erythrocyte membranes lack targeting properties and it is necessary to provide tumor-targeting function by modifying erythrocyte membranes. In this study, we report on a novel modification method of an erythrocyte membrane nanosystem to target tumors. Specifically, the tumor-targeting molecule folate-poly (ethylene glycol) (FA-PEG) was modified with a zwitterionic 2-(methyl acryloyoxy) ethyl choline phosphate (MCP) by the Michael addition reaction to obtain MCP-modified FA-PEG (MCP-PEG-FA). Based on the strong "N-P" tetravalent electrostatic interaction between MCP and phosphatidyl choline on the erythrocyte membranes, MCP-PEG-FA can be modified on the erythrocyte membrane encapsulated doxorubicin (DOX) loaded poly(lactic-co-glycolic acid) (PLGA) nanosystem to form a tumor-targeting erythrocyte membrane nanosystem (FA-RBC@PLGA-DOX). The results show that MCP-PEG-FA was synthesized and successfully bonded to the erythrocyte membrane nanosystem, and the FA-RBC@PLGA-DOX nanosystem had a better tumor-targeting function and tumor killing effect compared with those of the nanosystems without FA ligand modification. The universal modification method of erythrocyte membranes is successfully provided and can be applied to the treatment of various diseases.

Stimulus-responsive nanomaterials under physical regulation for biomedical applications

Cancer is a growing threat to human beings. Traditional treatments for malignant tumors usually involve invasive means to healthy human tissues, such as surgical treatment and chemotherapy. In recent years the use of specific stimulus-responsive materials in combination with some non-contact, non-invasive stimuli can lead to better efficacy and has become an important area of research. It promises to develop personalized treatment systems for four types of physical stimuli: light, ultrasound, magnetic field, and temperature. Nanomaterials that are responsive to these stimuli can be used to enhance drug delivery, cancer treatment, and tissue engineering. This paper reviews the principles of the stimuli mentioned above, their effects on materials, and how they work with nanomaterials. For this aim, we focus on specific applications in controlled drug release, cancer therapy, tissue engineering, and virus detection, with particular reference to recent photothermal, photodynamic, sonodynamic, magnetothermal, radiation, and other types of therapies. It is instructive for the future development of stimulus-responsive nanomaterials for these aspects.

Polymeric micelles of a copolymer composed of all-trans retinoic acid, methoxy-poly(ethylene glycol), and b-poly(N-(2 hydroxypropyl) methacrylamide) as a doxorubicin-delivery platform and for combination chemotherapy in breast cancer

Delivery of combination chemotherapeutic agents to the tumor via nanovesicles has the potential for superior tumor suppression and reduced toxicity. Herein, we prepare a block copolymer (mPH-RA) composed of methoxy-poly(ethylene glycol) (mPEG), b-poly(N-(2 hydroxypropyl) methacrylamide) (pHPMA), and all-trans retinoic acid (ATRA) by conjugating ATRA to the pre-formed copolymer, mPEG-b-pHPMA(mP-b-pH). Doxorubicin-loaded micelles, Dox@mP-b-pH, and Dox@mPH-RA were characterized by determining particle size, zeta potential, % DL, EE, Dox release, hemolysis study, and by DSC. The Dox@mPH-RA micelles (mPH-RA: Dox ratios of 10:0.5-2) displayed nano-size (36-45 nm), EE. 26-74%, and DL. 2.9-5.6%. Dox@mPH-RA micelles displayed the highest penetrability and cytotoxicity than free Dox and Dox@mP-b-pH micelles in breast cancer cell lines. Dox@mPH-RA exhibited the highest induction of apoptosis (94.1 ± 3%) than Dox (52.1 ± 4.5%), and Dox@mP-b-pH (81.7 ± 3%), and arrested cells in the highest population in G2 and S phase. Dox@mPH-RA increased the t_1/2 and C_max of Dox and demonstrated improved therapeutic efficacy and highest Dox distribution to the tumor. The Dox@mPH-RA increased the levels of apoptosis markers, caspase 3, 7, Ki-67, and caused the highest DNA fragmentation. The presence of RA improved the micelles' physicochemical properties, Dox-loading ability, and the therapeutic potential in Dox@mPH-RA via the combination therapeutic strategy.

A Biomimetic Drug Delivery System by Integrating Grapefruit Extracellular Vesicles and Doxorubicin-Loaded Heparin-Based Nanoparticles for Glioma Therapy

Existing nanoparticle-mediated drug delivery systems for glioma systemic chemotherapy remain a great challenge due to poor delivery efficiency resulting from the blood brain barrier/blood-(brain tumor) barrier (BBB/BBTB) and insufficient tumor penetration. Here, we demonstrate a distinct design by patching doxorubicin-loaded heparin-based nanoparticles (DNs) onto the surface of natural grapefruit extracellular vesicles (EVs), to fabricate biomimetic EV-DNs, achieving efficient drug delivery and thus significantly enhancing antiglioma efficacy. The patching strategy allows the unprecedented 4-fold drug loading capacity compared to traditional encapsulation for EVs. The biomimetic EV-DNs are enabled to bypass BBB/BBTB and penetrate into glioma tissues by receptor-mediated transcytosis and membrane fusion, greatly promoting cellular internalization and antiproliferation ability as well as extending circulation time. We demonstrate that a high-abundance accumulation of EV-DNs can be detected at glioma tissues, enabling the maximal brain tumor uptake of EV-DNs and great antiglioma efficacy in vivo.

Environmentally Self-Adaptative Nanocarriers Suppress Glioma Proliferation and Stemness via Codelivery of shCD163 and Doxorubicin

Gliomas-devastating intracranial tumors with a dismal outcome-are in dire need of innovative treatment. Although nanodrugs have been utilized as a target therapy for certain types of solid tumors, their therapeutic effects in gliomas are limited due to the complications of the systemic circulation, blood-brain barrier (BBB), and specific glioma environment. Thus, we aimed to establish a nanoliposome adaptable to different environments by codelivery of shCD163 and doxorubicin (DOX) to treat gliomas. In this study, we first synthesized pH-sensitive DSPE-cRGD-Hz-PEG₂₀₀₀ to form an environmentally self-adaptative nanoliposome (cRGD-DDD Lip) via a thin film method. We used in vitro BBB models, in vitro cell uptake experiments, and in vivo biodistribution assays to confirm the long circulation time and low cell uptake of the cRGD-DDD Lip as a result of the poly(ethylene glycol) (PEG) shell of cRGD-DDD Lip in the neutral pH systemic circulation. Moreover, the cRGD-DDD Lip bypassed the BBB and attached to the intracranial glioma following the removal of the PEG shell and the exposure of cRGD to the weakly acidic tumor microenvironment. We further assembled the shCD163/DOX@cRGD-DDD Lip through cRGD-DDD Lip loading of shCD163 and DOX. In vitro, cell proliferation and self-renewal of glioma cells were inhibited by the shCD163/DOX@cRGD-DDD Lip due to the toxicity of DOX and the suppression of shCD163 via the CD163 pathway. In vivo, the shCD163/DOX@cRGD-DDD Lip disturbed the progression of in situ gliomas by inhibiting the growth and stemness of glioma cells and prevented the recurrence of gliomas after resection. In conclusion, the cRGD-DDD Lip may be a promising nanodrug-loading platform to cope with different environments and the shCD163/DOX@cRGD-DDD Lip may potentially be a novel nanodrug for glioma therapy.

The pH-triggered polyglutamate brush co-delivery of MDR1 and survivin-targeting siRNAs efficiently overcomes multi-drug resistance of NSCLC

Multi-drug resistance (MDR) is one of the major challenges in the successful chemotherapy of non-small cell lung cancer (NSCLC). Although RNA interference (RNAi) has been widely used to silence resistance-related genes, the effect remains unsatisfactory. In this study, we attempted to overcome MDR of NSCLC by simultaneously interfering with two RNAs that have different functions. A new pH-triggered polyglutamate brush polymer dimethylmaleic anhydride-poly(ethyleneglycol) monomethyl ether-b-polyglutamate-g-spermine (DMA-mPEG-b-PG-g-spermine, DPPGS) was designed and synthesized. The DPPGS/small interfering RNA (siRNA) complex nanoparticles (DPPGSN) were prepared. The results demonstrated that DPPGSN could be transformed from a negatively charged form into a positively charged form in the slightly acidic tumor extracellular environment. The siRNA targeting MDR1 mRNA (siMDR1) and siRNA targeting survivin mRNA (siSurvivin) could be efficiently co-delivered by DPPGS to simultaneously interfere with two genes (p < 0.01). Furthermore, DPPGS co-delivery of siMDR1 and siSurvivin lowered the IC₅₀ value of cisplatin (DDP) in A549/DDP (p < 0.01) cells and increased the apoptosis rate of the cells (p < 0.01). Therefore, co-delivery of siMDR1 and siSurvivin using DPPGS would be a promising approach for overcoming MDR of NSCLC.