A pH-responsive mesoporous silica nanoparticle-based drug delivery system for targeted breast cancer therapy

For and against tumor microenvironment: Nanoparticle-based strategies for active cancer therapy

Cancer treatment is challenged by the tumor microenvironment (TME), which promotes drug resistance and cancer cell growth. This review offers a comprehensive and innovative perspective on how nanomedicine can modify the TME to enhance therapy. Strategies include using nanoparticles to improve oxygenation, adjust acidity, and alter the extracellular matrix, making treatments more effective. Additionally, nanoparticles can enhance immune responses by activating immune cells and reducing suppression within tumors. By integrating these approaches with existing therapies, such as chemotherapy and radiotherapy, nanoparticles show promise in overcoming traditional treatment barriers. The review discusses how changes in the TME can enhance the effectiveness of nanomedicine itself, creating a reciprocal relationship that boosts overall efficacy. We also highlight novel strategies aimed at exploiting and overcoming the TME, leveraging nanoparticle-based approaches for targeted cancer therapy through precise TME modulation.

Chitosan and hyaluronic acid in breast cancer treatment: Anticancer efficacy and nanoparticle and hydrogel development

The pervasive global health concern of breast cancer necessitates the development of innovative therapeutic interventions to enhance efficacy and mitigate adverse effects. Chitosan and hyaluronic acid, recognized for their biocompatibility and biodegradability, present compelling options for the novel drug delivery systems and therapeutic platforms in the context of breast cancer management. This review will delineate the distinctive attributes of chitosan and hyaluronic acid, encompassing their inherent anticancer properties, targeting capabilities, and suitability for chemical modifications along with nanoparticle development. These characteristics render them exceptionally well-suited for the fabrication of nanoparticles and hydrogels. The intrinsic anticancer potential of chitosan, in conjunction with its mucoadhesive properties, and the robust binding affinity of hyaluronic acid to CD44 receptors, facilitate specific drug delivery to the malignant cells, thus circumventing the limitations inherent in traditional treatment modalities such as chemotherapy. The incorporation of these materials into nanocarriers allows for the co-delivery of therapeutic agents, thereby potentiating synergistic effects, while hydrogel systems provide localized, controlled drug release and facilitate tissue regeneration. An analysis of advancements in their synthesis, functionalization, and application is presented, while also acknowledging challenges pertaining to scalability and clinical translation.

Design of pH-Responsive Nanomaterials Based on the Tumor Microenvironment

The metabolic activity of tumor cells leads to the acidification of the surrounding microenvironment, which provides new strategies for the application of nanotechnology in cancer therapy. Researchers have developed various types of pH-responsive nanomaterials based on the tumor acidic microenvironment. This review provides an in-depth discussion on the design mechanisms, drug-loading strategies, and application pathways of tumor acidic microenvironment-responsive nanodrug delivery systems. These materials trigger drug release upon reaching the tumor microenvironment, enhancing therapeutic targeting and reducing toxicity to healthy cells. pH-responsive nanomaterials include organic nanomaterials, inorganic nanomaterials, and composite nanomaterials. Additionally, this review outlines the drug-loading strategies, application prospects, and challenges of pH-responsive nanomaterials, aiming to promote the development and clinical translation of this field.

Review of recent preclinical and clinical research on ligand-targeted liposomes as delivery systems in triple negative breast cancer therapy

Triple-negative breast Cancer (TNBC) is one of the deadliest types, making up about 20% of all breast cancers. Chemotherapy is the traditional manner of progressed TNBC treatment; however, it has a short-term result with a high reversibility pace. The lack of targeted treatment limited and person-dependent treatment options for those suffering from TNBC cautions to be the worst type of cancer among breast cancer patients. Consequently, appropriate treatment for this disease is considered a major clinical challenge. Therefore, various treatment methods have been developed to treat TNBC, among which chemotherapy is the most common and well-known approach recently studied. Although effective methods are chemotherapies, they are often accompanied by critical limitations, especially the lack of specific functionality. These methods lead to systematic toxicity and, ultimately, the expansion of multidrug-resistant (MDR) cancer cells. Therefore, finding novel and efficient techniques to enhance the targeting of TNBC treatment is an essential requirement. Liposomes have demonstrated that they are an effective method for drug delivery; however, among a large number of liposome-based drug delivery systems annually developed, a small number have just received authorization for clinical application. The new approaches to using liposomes target their structure with various ligands to increase therapeutic efficiency and diminish undesired side effects on various body tissues. The current study describes the most recent strategies and research associated with functionalizing the liposomes' structure with different ligands as targeted drug carriers in treating TNBCs in preclinical and clinical stages.

Label-free fluorescent biosensor based on AuNPs etching releasing signal for miRNA-155 detection

Quantitative microRNA (miRNA) detection is crucial for early breast cancer diagnosis and prognosis. However, quick and stable fluorescence sensing for miRNA identification is still challenging. This work developed a novel label-free detection method based on AuNPs etching for quantitatively detecting miRNA-155. A layer of AuNPs was grown on the surface of mesoporous silica nanoparticles (MSN) loaded with Rhodamine 6G (R6G) using seed-mediated growth, followed by probe attachment. In the presence of miRNA-155, the MSN@R6G@AuNP surface loses the protection of the attached probe, rendering AuNPs susceptible to etching by hydrochloric acid. This results in a significant fluorescent signal being released in the free space. The encapsulation with AuNPs effectively reduces signal leakage, while the rapid etching process shortens detection time. This strategy enables sensitive and fast detection with a detection range of 100 fM to 100 nM, a detection limit of 2.18 fM, and a detection time of 30 min. The recovery rate in normal human serum ranges from 99.02 % to 106.34 %. This work presents a simple biosensing strategy with significant potential for application in tumor diagnosis.

Advances in inorganic nanoparticles-based drug delivery in targeted breast cancer theranostics

Theranostic nanoparticles (NPs) have the potential to dramatically improve cancer management by providing personalized medicine. Inorganic NPs have attracted widespread interest from academic and industrial communities because of their unique physicochemical properties (including magnetic, thermal, and catalytic performance) and excellent functions with functional surface modifications or component dopants (e.g., imaging and controlled release of drugs). To date, only a restricted number of inorganic NPs are deciphered into clinical practice. This review highlights the recent advances of inorganic NPs in breast cancer therapy. We believe that this review can provides various approaches for investigating and developing inorganic NPs as promising compounds in the future prospects of applications in breast cancer treatment and material science.

Leveraging high-throughput screening technologies in targeted mRNA delivery

Messenger ribonucleic acid (mRNA) has emerged as a promising molecular preventive and therapeutic approach that opens new avenues for healthcare. Although the use of delivery systems, especially lipid nanoparticles (LNPs), greatly improves the efficiency and stability of mRNA, mRNA tends to accumulate in the liver and hardly penetrates physiological barriers to reach the target site after intravenous injection. Hence, the rational design of targeting strategies aimed at directing mRNA to specific tissues and cells remains an enormous challenge in mRNA therapy. High-throughput screening (HTS) is a cutting-edge targeted technique capable of synthesizing chemical compound libraries for the large-scale experiments to validate the efficiency of mRNA delivery system. In this review, we firstly provide an overview of conventional low-throughput targeting strategies. Then the latest advancements in HTS techniques for mRNA targeted delivery, encompassing optimizing structures of large-scale delivery vehicles and developing large-scale surface ligands, as well as the applications of HTS techniques in extrahepatic systemic diseases are comprehensively summarized. Moreover, we illustrate the selection of administration routes for targeted mRNA delivery. Finally, challenges in the field and potential solutions to tackle them are proposed, offering insights for future development toward mRNA targeted therapy.

Synthesis of Mesoporous Silica Using the Sol-Gel Approach: Adjusting Architecture and Composition for Novel Applications

The sol-gel chemistry of silica has long been used for manipulating the size, shape, and microstructure of mesoporous silica particles. This manipulation is performed in mild conditions through controlling the hydrolysis and condensation of silicon alkoxide. Compared to amorphous silica particles, the preparation of mesoporous silica, such as MCM-41, using the sol-gel approach offers several unique advantages in the fields of catalysis, medicament, and environment, due to its ordered mesoporous structure, high specific surface area, large pore volume, and easily functionalized surface. In this review, our primary focus is on the latest research related to the manipulation of mesoporous silica architectures using the sol-gel approach. We summarize various structures, including hollow, yolk-shell, multi-shelled hollow, Janus, nanotubular, and 2D membrane structures. Additionally, we survey sol-gel strategies involving the introduction of various functional elements onto the surface of mesoporous silica to enhance its performance. Furthermore, we outline the prospects and challenges associated with mesoporous silica featuring different structures and functions in promising applications, such as high-performance catalysis, biomedicine, wastewater treatment, and CO2 capture.

Morin-Based Nanoparticles for Regulation of Blood Glucose

Morin, a naturally occurring bioactive compound shows great potential as an antioxidant, anti-inflammatory agent, and regulator of blood glucose levels. However, its low water solubility, poor lipid solubility, limited bioavailability, and rapid clearance in vivo hinder its application in blood glucose regulation. To address these limitations, we report an enzymatically synthesized nanosized morin particle (MNs) encapsulated in sodium alginate microgels (M@SA). This approach significantly enhances morin's delivery efficiency and therapeutic efficacy in blood glucose regulation. Utilizing horseradish peroxidase, we synthesized MNs averaging 305.7 ± 88.7 nm in size. These MNs were then encapsulated via electrohydrodynamic microdroplet spraying to form M@SA microgels. In vivo studies revealed that M@SA microgels demonstrated prolonged intestinal retention and superior efficacy compared with unmodified morin and MNs alone. Moreover, MNs notably improved glucose uptake in HepG2 cells. Furthermore, M@SA microgels effectively regulated blood glucose, lipid profiles, and oxidative stress in diabetic mice while mitigating liver, kidney, and pancreatic damage and enhancing anti-inflammatory responses. Our findings propose a promising strategy for the oral administration of natural compounds for blood glucose regulation, with implications for broader therapeutic applications.

Red blood cell membrane-coated functionalized Cu-doped metal organic framework nanoformulations as a biomimetic platform for improved chemo-/chemodynamic/photothermal synergistic therapy

Nanoformulations for combining chemotherapy, chemodynamic therapy, and photothermal therapy have enormous potential in tumor treatment. Coating nanoformulations with cell membranes endows them with homologous cellular mimicry, enabling nanoformulations to acquire new functions and properties, including homologous targeting and long circulation in vivo, and can enhance internalization by homologous cancer cells. Herein, we fused multifunctional biomimetic nanoformulations based on Cu-doped zeolitic imidazolate framework-8 (ZIF-8). Hydroxycamptothecin (HCPT), a clinical anti-tumor drug, was encapsulated into ZIF-8, which was subsequently coated with polydopamine (PDA) and red blood cell membrane. The as-fabricated biomimetic nanoformulations showed an enhanced cell uptake in vitro and the potential to prolong blood circulation in vivo, producing effective synergistic chemotherapy, chemodynamic therapy, and photothermal therapy under the 808 nm laser irradiation. Together, the biomimetic nanoformulations showed a prolonged blood circulation and evasion of immune recognition in vivo to provide a bio-inspired strategy which may have the potential for the multi-synergistic therapy of breast cancer.

Nanoparticle-mediated dsRNA delivery for precision insect pest control: a comprehensive review

Nanoparticle-based delivery systems have emerged as powerful tools in the field of pest management, offering precise and effective means of delivering double-stranded RNA (dsRNA), a potent agent for pest control through RNA interference (RNAi). This comprehensive review aims to evaluate and compare various types of nanoparticles for their suitability in dsRNA delivery for pest management applications. The review begins by examining the unique properties and advantages of different nanoparticle materials, including clay, chitosan, liposomes, carbon, gold and silica. Each material's ability to protect dsRNA from degradation and its potential for targeted delivery to pests are assessed. Furthermore, this review delves into the surface modification strategies employed to enhance dsRNA delivery efficiency. Functionalization with oligonucleotides, lipids, polymers, proteins and peptides is discussed in detail, highlighting their role in improving stability, cellular uptake, and specificity of dsRNA delivery.This review also provides valuable guidance on choosing the most suitable nanoparticle-based system for delivering dsRNA effectively and sustainably in pest management. Moreover, it identifies existing knowledge gaps and proposes potential research directions aimed at enhancing pest control strategies through the utilization of nanoparticles and dsRNA.

Effect of zwitterionic sulfobetaine incorporation on blood behaviours, phagocytosis, and in vivo biodistribution of pH-responsive micelles with positive charges

pH-responsive micelles with positive charges are challenged by their significant effect on the cells/proteins and compromise their final fate due to electrostatic interactions. As one of the promising strategies, zwitterion incorporation in micelles has attracted considerable attention and displayed improved protein adsorption and blood circulation performances. However, previous reports in this field have been mostly limited in hemolysis for studying blood behaviour and lack a comprehensive understanding of their interactions with blood components. Herein, we present a prelimilary study on the effect of zwitterionic sulfobetaine incorporation on blood behaviour, phagocytosis, and in vivo biodistribution of pH-responsive micelles with positive charges. Amphiphilic triblock copolymers, namely poly(ε-caprolactone)-b-poly(N,N-diethylaminoethyl methacrylate)-(N-(3-sulfopropyl-N-methacryloxyethy-N,N-diethylammonium betaine)) (PCL-PDEAPSx, x = 2, 6, 10), containing different numbers of sulfobetaine groups were synthesized through four steps to prepare the pH-responsive micelles with positive charges. The effect of the sulfobetaine incorporation displayed different profiles, e.g., the micelles had no effect on RBC aggregation, thrombin time (TT), and platelet aggregation, while the cytotoxicity, hemolysis, RBC deformability, activated partial thromboplastin time (APTT), prothrombin time (PT), platelet activation, protein (albumin, fibrinogen, plasma) adsorption, phagocytosis, and in vivo biodistribution decreased with the increase in the sulfobetaine number, in which the transition mainly occurred at a sulfobetaine/tertiary amine group ratio of 3/7-1/1 compared to that of the mPEG control. In addition, the micelles displayed a strong inhibitory effect on the intrinsic coagulation pathway, which was associated with a significant decrease in the coagulation factor activity. Based on these findings, the related mechanism is discussed and proposed, which can aid the rational design of pH-responsive micelles for improved therapeutics.

Polymeric Micelle-Based Nanogels as Emerging Drug Delivery Systems in Breast Cancer Treatment: Promises and Challenges

Breast cancer is a pervasive global health issue that disproportionately impacts the female population. Over the past few years, there has been considerable interest in nanotechnology due to its potential utility in creating drug-delivery systems designed to combat this illness. The primary aim of these devices is to enhance the delivery of targeted medications, optimise the specific cells that receive the drugs, tackle treatment resistance in malignant cells, and introduce novel strategies for preventing and controlling diseases. This research aims to examine the methodologies utilised by various carrier nanoparticles in the context of therapeutic interventions for breast cancer. The main objective is to investigate the potential application of novel delivery technologies to attain timely and efficient diagnosis and treatment. Current cancer research predominantly examines diverse drug delivery methodologies for chemotherapeutic agents. These methodologies encompass the development of hydrogels, micelles, exosomes, and similar compounds. This research aims to analyse the attributes, intricacies, notable advancements, and practical applications of the system in clinical settings. Despite the demonstrated efficacy of these methodologies, an apparent discrepancy can be observed between the progress made in developing innovative therapeutic approaches and their widespread implementation in clinical settings. It is critical to establish a robust correlation between these two variables to enhance the effectiveness of medication delivery systems based on nanotechnology in the context of breast cancer treatment.

Preparation and anti-tumor effects of mesoporous silica nanoparticles loaded with trifluoperazine

We have developed a targeted nano-drug delivery system that effectively harnesses the anti-tumor properties of trifluoperazine (TFP), while concurrently mitigating its side effects on the central nervous system. The manufacturing process entailed the preparation of mesoporous silica nanoparticles (MSN-NH2), followed by the loading of trifluoperazine into the pores of MSN-NH2 and then surface modification with polyethylene glycol (PEG) and anisamide (AA), resulting in the formation of TFP@MSN@PEG-AA (abbreviated as TMPA) nanoparticles. In vitro and in vivo anti-tumor activity and hemolysis experiments showed that TMPA had an excellent safety profile and a good anti-tumor effect. Importantly, the drug content of the TMPA nanoparticle group was found to be significantly lower than that of the TFP group in the mouse brain tissue as determined by High Performance Liquid Chromatography (HPLC) detection. Therefore, the developed drug delivery system achieved the goal of maintaining TFP's anti-tumor action while avoiding its negative effects on the central nervous system.

Erbium-ytterbium containing upconversion mesoporous bioactive glass microspheres for tissue engineering: luminescence monitoring of biomineralization and drug release

The development of functional biomaterials with real-time monitoring of mineralization processes, drug release and biodistribution has potential applications but remains an unsolved challenge. Herein, erbium- and ytterbium- containing mesoporous bioactive glass microspheres (MBGs:Er/Yb) with blue and red emission at an excitation wavelength of 980 nm were synthesized by a sol-gel combined with organic template method. As the concentration of Yb3+ ions gradually increases, the emission intensity of the MBGs:Er/Yb exhibits a clear concentration quenching effect. Combined with in vitro bioactivity tests, the optimal molar ratio of Er3+/Yb3+ was determined to be 4:3. Therefore, MBGs:4Er/3Yb was selected for in vitro biomineralization and drug release monitoring. The results of biomineralization monitoring show that the upconversion luminescence intensity is closely related to the degree of biomineralization. The upconversion luminescence intensity of MBGs:4Er/3Yb is quenched with the increase of the degree of biomineralization. The degree of luminescence quenching during biomineralization can be semiquantized. Drug release monitoring experiments showed that the anticancer drug doxorubicin hydrochloride (DOX) was successfully loaded into MBGs:4Er/3Yb and selectively quenched the green emission. When DOX was released, the green emission recovered stably, and It/I0 increased gradually. Moreover, there was a linear relationship between It/I0 and cumulative drug release, indicating that DOX-MBGs:4Er/3Yb is highly sensitive to DOX release, and monitoring the It/I0 values of DOX-MBGs:4Er/3Yb can achieve real-time tracking of the DOX release process to a certain extent. In conclusion, MBGs:4Er/3Yb has potential application as an upconversion luminescence biomonitoring material in the field of bone tissue engineering. STATEMENT OF SIGNIFICANCE: Mesoporous bioactive glasses have great potential for applications in bone tissue repair due to their excellent biological properties, but the effective information of the repair process cannot be grasped in a timely manner. Therefore, real-time monitoring of mineralization and drug release processes will be beneficial to obtain the degree of healing and optimize the amount and distribution of drugs to improve targeted therapeutic effects. For biomaterials, in vitro biological properties determine their biological properties in vivo, where the environment is more complex and diverse, and thus in vitro biomonitoring is particularly crucial. The organic combination of physical properties and biological properties will also provide a feasible idea for the development of biomaterials.

Endogenous NO-release multi-responsive hollow mesoporous silica nanoparticles for drug encapsulation and delivery

Novel multi-responsive drug delivery vehicles (CDs/PNVCL@HMSNs) were prepared by grafting amino-terminated poly (N-vinyl caprolactam) (PNVCL-NH₂) and amino-rich carbon dots (CDs) on the surface of aldehyde-functionalized HMSNs (HMSNs-CHO) via Schiff base reaction. The CDs were prepared from L-arginine and their surfaces were rich in guanidine. Doxorubicin (DOX) was loaded into the nanoparticles to form drug loaded vehicles (CDs/PNVCL@HMSNs-DOX) and the drug loading efficiency was 58.38%. The drug release behaviors of CDs/PNVCL@HMSNs-DOX showed temperature and pH responsiveness due to the poly (N-vinyl caprolactam) (PNVCL) and Schiff base bond. The high concentration of NO released in high concentration H₂O₂ of tumor site could induce tumor cells apoptosis. The multi-responsive CDs/PNVCL@HMSNs are intriguing drug carriers, which combine drug delivery and NO release in one.

Nanocomposite formulation for a sustained release of free drug and drug-loaded responsive nanoparticles: an approach for a local therapy of glioblastoma multiforme

Malignant gliomas are a type of primary brain tumour that originates in glial cells. Among them, glioblastoma multiforme (GBM) is the most common and the most aggressive brain tumour in adults, classified as grade IV by the World Health Organization. The standard care for GBM, known as the Stupp protocol includes surgical resection followed by oral chemotherapy with temozolomide (TMZ). This treatment option provides a median survival prognosis of only 16-18 months to patients mainly due to tumour recurrence. Therefore, enhanced treatment options are urgently needed for this disease. Here we show the development, characterization, and in vitro and in vivo evaluation of a new composite material for local therapy of GBM post-surgery. We developed responsive nanoparticles that were loaded with paclitaxel (PTX), and that showed penetration in 3D spheroids and cell internalization. These nanoparticles were found to be cytotoxic in 2D (U-87 cells) and 3D (U-87 spheroids) models of GBM. The incorporation of these nanoparticles into a hydrogel facilitates their sustained release in time. Moreover, the formulation of this hydrogel containing PTX-loaded responsive nanoparticles and free TMZ was able to delay tumour recurrence in vivo after resection surgery. Therefore, our formulation represents a promising approach to develop combined local therapies against GBM using injectable hydrogels containing nanoparticles.

Small molecules as cancer targeting ligands: Shifting the paradigm

Conventional chemotherapeutics exploration is hampered due to their nonspecific distribution leading to unintended serious toxicity. Toxicity is so severe that deciding to go for chemotherapy becomes a question of concern for many terminally ill cancer patients. However, with evolving times nanotechnology assisted in reducing the haywire distribution and channelizing the movement of drug-enclosing drug delivery systems to cancer cells to a greater extent, yet toxicity issues still could not be obliterated. Thus, active targeting appeared as a refuge, where ligands actively or specifically deliver linked chemotherapeutics and carriers to cancer cells. For a very long time, large molecule weight/macromolecular ligands (peptides and big polymers) were considered the first choice for ligand-directed active cancer targeting, due to their specificity towards overexpressed native cancer receptors. However, complex characterization, instability, and the expensive nature demanded to reconnoitre better alternatives for macromolecule ligands. The concept of small molecules as ligands emerged from the idea that few chemical molecules including chemotherapeutics have a higher affinity for cancer receptors, which are overexpressed on cell membranes, and may have the ability to assist in drug cellular uptake through endocytosis. But now the question is, can they assist the conjugated macro cargos to enter the cell or not? This present review will provide a holistic overview of the small molecule ligands explored till now.

Recent Advances in Mesoporous Silica Nanoparticle-Mediated Drug Delivery for Breast Cancer Treatment

Breast cancer (BC) currently occupies the second rank in cancer-related global female deaths. Although consistent awareness and improved diagnosis have reduced mortality in recent years, late diagnosis and resistant response still limit the therapeutic efficacy of chemotherapeutic drugs (CDs), leading to relapse with consequent invasion and metastasis. Treatment with CDs is indeed well-versed but it is badly curtailed with accompanying side effects and inadequacies of site-specific drug delivery. As a result, drug carriers ensuring stealth delivery and sustained drug release with improved pharmacokinetics and biodistribution are urgently needed. Core-shell mesoporous silica nanoparticles (MSNPs) have recently been a cornerstone in this context, attributed to their high surface area, low density, robust functionalization, high drug loading capacity, size-shape-controlled functioning, and homogeneous shell architecture, enabling stealth drug delivery. Recent interest in using MSNPs as drug delivery vehicles has been due to their functionalization and size-shape-driven versatilities. With such insights, this article focuses on the preparation methods and drug delivery mechanisms of MSNPs, before discussing their emerging utility in BC treatment. The information compiled herein could consolidate the database for using inorganic nanoparticles (NPs) as BC drug delivery vehicles in terms of design, application and resolving post-therapy complications.

Co-delivery of carbonic anhydrase IX inhibitor and doxorubicin as a promising approach to address hypoxia-induced chemoresistance

Hypoxia, an oxygen-deprived condition of the tumor, is one of the major reasons for resistance to chemotherapy. Carbonic anhydrases are generally involved in pH homeostasis in normal conditions, but in solid tumors having a strong relation with hypoxia, the carbonic anhydrase IX (CA-IX) enzyme is overexpressed and results in an extracellular acidic environment. For most weakly basic anticancer drugs, including doxorubicin (Dox), the ionization in an acidic environment limits their cellular uptake, and consequently, the tumor exposure to the drug at sub-therapeutic concentration comes out as chemoresistance. Herein, a combined drug delivery system of liposomes and mesoporous silica nanoparticles (MSNPs) was developed for the co-delivery of the CA-IX enzyme inhibitor and Dox in hypoxic condition. The unique structure of MSNPs with higher surface area was utilized for higher drug loading and sustained release of Dox. Additionally, the biocompatible nature of liposomal coating as a second loading site for the CA-IX enzyme inhibitor has provided gatekeeping effects at pore opening to avoid premature drug release. Lipid coated MSNPs as a co-delivery system for Dox and the CA-IX inhibitor have synergistic cytotoxic effects against MDA-MB 231 breast cancer cells in hypoxic conditions. These findings assure the potential of this drug delivery system to overcome hypoxia-related chemoresistance.