Blood component ridable and CD44 receptor targetable nanoparticles based on a maleimide-functionalized chondroitin sulfate derivative

Decorating Delivery Vehicles Using Hyaluronic Acid Oligosaccharides Enables Active Targeting Toward Cancer and Minimizes Adverse Effect of Chemotherapeutics

The major drawback of conventional chemotherapeutic treatment is the non-specificity or inability to ascertain and target cancerous cells directly. In this study, an active targeting strategy that is poised to carry the anticancer agents to the desired sites for therapeutic action while avoiding toxicity to normal organs is provided. The active targeting of delivery vehicles is achieved by ligand-receptor interactions, in particular the specific binding between hyaluronic acid oligosaccharides (oHAs) and CD44 receptors. This study first prepares oHAs by the size-exclusion chromatography and utilizes them to decorate chitosan (CTS) as basic materials (oHAs-CTS) for drug delivery, then fabricates oHAs-CTS into micro/nanoscale carriers to encapsulate agents for cancer chemotherapy. The oHAs-CTS micro/nanocarriers exhibit high drug encapsulation efficiency (58-87%), and the drug releases present a sustained behavior. Notably, oHAs-CTS delivery vehicles display an enhanced active targeting toward cancers and alleviate the cytotoxic effects on normal cells. Additionally, in vivo results show that drug-laden oHAs-CTS nanocarriers demonstrate a significant inhibitory effect on 4 T1 tumors without any toxicity to the major organs. Taken together, the findings highlight the potential of oHAs-CTS micro/nanospheres as delivery vehicles with enhanced active targeted capability toward cancers and minimized adverse effects of chemotherapeutic agents for cancer treatment.

Laser-responsive erastin-loaded chondroitin sulfate nanomedicine targeting CD44 and system xc- in liver cancer: A non-ferroptotic approach

Erastin, a ferroptosis-inducing system xc- inhibitor, faces clinical challenges due to suboptimal physicochemical and pharmacokinetic properties, as well as relatively low potency and off-target toxicity. Addressing these, we developed ECINs, a novel laser-responsive erastin-loaded nanomedicine utilizing indocyanine green (ICG)-grafted chondroitin sulfate A (CSA) derivatives. Our aim was to improve erastin's tumor targeting via CSA-CD44 interactions and enhance its antitumor efficacy through ICG's photothermal and photodynamic effects in the laser-on state while minimizing off-target effects in the laser-off state. ECINs, with their nanoscale size of 186.7 ± 1.1 nm and high erastin encapsulation efficiency of 93.0 ± 0.8%, showed excellent colloidal stability and sustained drug release up to 120 h. In vitro, ECINs demonstrated a mechanism of cancer cell inhibition via G1-phase cell cycle arrest, indicating a non-ferroptotic action. In vivo biodistribution studies in SK-HEP-1 xenograft mice revealed that ECINs significantly enhanced tumor distribution of erastin (1.9-fold greater than free erastin) while substantially reducing off-target accumulation in the lungs and spleen by 203-fold and 19.1-fold, respectively. Combined with laser irradiation, ECINs significantly decreased tumor size (2.6-fold, compared to free erastin; 2.4-fold, compared to ECINs without laser irradiation) with minimal systemic toxicity. This study highlights ECINs as a dual-modality approach for liver cancer treatment, demonstrating significant efficacy against tumors overexpressing CD44 and system xc-.

CD44 targeted-chondroitin sulfate nanoparticles: Fine-tuning hydrophobic groups to enhance in vitro pH-responsiveness and in vivo efficacy for advanced breast cancer treatment

The design of tumor-targeting nanoparticles with precisely controlled physical-biological properties may improve the delivery of chemotherapeutic agents. This study introduces pH-sensitive chondroitin sulfate-cholesterol (ChS-Chol) nano-assemblies for targeted intracellular doxorubicin (Dox) delivery in breast cancer treatment. Various ChS-Chol copolymers were synthesized, yielding self-assembling nanostructures with adjustable lipophilic content. In an aqueous environment, the ChS-Chol conjugates could form self-assembled nanostructures with a narrower size variation and a high negative potential. Moreover, the carriers would rapidly disassemble and release Dox in response to acidic pH. The in vitro cytotoxicity assay exhibited concentration-related anti-proliferation activity with Dox-loaded nanoparticles against 4T1, MCF-7, and MDA-MB-231 breast cancer cells. The nanoparticles demonstrated enhanced early apoptosis induction, efficient cellular uptake, and improved prevention of tumor cell proliferation compared to free Dox. In vivo results showcased significant tumor growth inhibition, underscoring the potential of these nanoparticle-based drug delivery systems for breast cancer therapy. The study emphasizes tailored nanocarrier design, leveraging pH-responsiveness and precise hydrophobic tuning to achieve targeted and potent therapeutic effects in the fight against breast cancer.

Chondroitin Sulfate-Derived Micelles for Adipose Tissue-Targeted Delivery of Celastrol and Phenformin to Enhance Obesity Treatment

Adipose tissue macrophages (ATMs) are crucial in maintaining a low-grade inflammatory microenvironment in adipose tissues (ATs). Modulating ATM polarization to attenuate inflammation represents a potential strategy for treating obesity with insulin resistance. This study develops a combination therapy of celastrol (CLT) and phenformin (PHE) using chondroitin sulfate-derived micelles. Specifically, CLT-loaded 4-aminophenylboronic acid pinacol ester-modified chondroitin sulfate micelle (CS-PBE/CLT) and chondroitin sulfate-phenformin conjugate micelles (CS-PHE) were synthesized, which were shown to actively target ATs through CD44-mediated pathways. Furthermore, the dual micellar systems significantly reduced inflammation and lipid accumulation via protein quantification and Oil Red O staining. In preliminary in vivo studies, we performed H&E staining, immunohistochemical staining, insulin tolerance test, and glucose tolerance test, and the results showed that the combination therapy using CS-PBE/CLT and CS-PHE micelles significantly reduced the average body weight, white adipose tissue mass, and liver mass of high-fat diet-fed mice while improving their systemic glucose homeostasis. Overall, this combination therapy presents a promising alternative to current treatment options for diet-induced obesity.

Golgi Apparatus-Targeted Photodynamic Therapy for Enhancing Tumor Immunogenicity by Eliciting NLRP3 Protein-Dependent Pyroptosis

Innate and adaptive immunity is important for initiating and maintaining immune function. The nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome serves as a checkpoint in innate and adaptive immunity, promoting the secretion of pro-inflammatory cytokines and gasdermin D-mediated pyroptosis. As a highly inflammatory form of cell death distinct from apoptosis, pyroptosis can trigger immunogenic cell death and promote systemic immune responses in solid tumors. Previous studies proposed that NLRP3 was activated by translocation to the mitochondria. However, a recent authoritative study has challenged this model and proved that the Golgi apparatus might be a prerequisite for the activation of NLRP3. In this study, we first developed a Golgi apparatus-targeted photodynamic strategy to induce the activation of NLRP3 by precisely locating organelles. We found that Golgi apparatus-targeted photodynamic therapy could significantly upregulate NLRP3 expression to promote the subsequent release of intracellular proinflammatory contents such as IL-1β or IL-18, creating an inflammatory storm to enhance innate immunity. Moreover, this acute NLRP3 upregulation also activated its downstream classical caspase-1-dependent pyroptosis to enhance tumor immunogenicity, triggering adaptive immunity. Pyroptosis eventually led to immunogenic cell death, promoted the maturation of dendritic cells, and effectively activated antitumor immunity and long-lived immune memory. Overall, this Golgi apparatus-targeted strategy provided molecular insights into the occurrence of immunogenic pyroptosis and offered a platform to remodel the tumor microenvironment.

Advances in dendritic cell targeting nano-delivery systems for induction of immune tolerance

Dendritic cells (DCs) are the major specialized antigen-presenting cells (APCs), play a key role in initiating the body's immune response, maintain the balance of immunity. DCs can also induce immune tolerance by rendering effector T cells absent and anergy, and promoting the expansion of regulatory T cells. Induction of tolerogenic DCs has been proved to be a promising strategy for the treatment of autoimmune diseases, organ transplantation, and allergic diseases by various laboratory researches and clinical trials. The development of nano-delivery systems has led to advances in situ modulation of the tolerance phenotype of DCs. By changing the material composition, particle size, zeta-potential, and surface modification of nanoparticles, nanoparticles can be used for the therapeutic payloads targeted delivery to DCs, endowing them with great potential in the induction of immune tolerance. This paper reviews how nano-delivery systems can be modulated for targeted delivery to DCs and induce immune tolerance and reviews their potential in the treatment of autoimmune diseases, organ transplantation, and allergic diseases.

Extracellular matrix component-derived nanoparticles for drug delivery and tissue engineering

The extracellular matrix (ECM) consists of a complex combination of proteins, proteoglycans, and other biomolecules. ECM-based materials have been demonstrated to have high biocompatibility and bioactivity, which may be harnessed for drug delivery and tissue engineering applications. Herein, nanoparticles incorporating ECM-based materials and their applications in drug delivery and tissue engineering are reviewed. Proteins such as gelatin, collagen, and fibrin as well as glycosaminoglycans including hyaluronic acid, chondroitin sulfate, and heparin have been employed for cancer therapeutic delivery, gene delivery, and wound healing and regenerative medicine. Strategies for modifying and functionalizing these materials with synthetic and natural polymers or to enable stimuli-responsive degradation and drug release have increased the efficacy of these materials and nano-systems. The incorporation and modification of ECM-based materials may be used to drive drug targeting and increase tissue-specific cell differentiation more effectively.

Bone tumor-homing nanotherapeutics for prolonged retention in tumor microenvironment and facilitated apoptotic process via mevalonate pathway inhibition

Bone malignancy features a mineralized extracellular matrix primarily composed of hydroxyapatite, which interferes with the distribution and activity of antineoplastic agents. Herein, we report bone tumor-homing polymeric nanotherapeutics consisting of alendronate-decorated chondroitin sulfate A-graft-poly(lactide-co-glycolide) and doxorubicin (DOX), named PLCSA-AD, which displayed a prolonged retention profile in the tumor microenvironment and augmented therapeutic efficacy via inhibition of the mevalonate pathway. PLCSA-AD exhibited a 1.72-fold lower IC50 value than free DOX and a higher affinity for hydroxyapatite than PLCSA in HOS/MNNG cell-based 2D bone tumor-mimicking models. The inhibition of the mevalonate pathway by PLCSA-AD in tumor cells was verified by investigating the cytosolic fraction of unprenylated proteins, where blank PLCSA-AD significantly increased the expression of cytosolic Ras and RhoA without changing their total cellular amounts. In a bone tumor-mimicking xenografted mouse model, AD-decorated nanotherapeutics significantly increased tumor accumulation (1.73-fold) compared with PLCSA, and higher adsorption to hydroxyapatites was observed in the histological analysis of the tumor. As a result, inhibition of the mevalonate pathway and improvement in tumor accumulation led to markedly enhanced therapeutic efficacy in vivo, suggesting that PLCSA-AD could be promising nanotherapeutics for bone tumor treatment.

Modulating tumor-stromal crosstalk via a redox-responsive nanomedicine for combination tumor therapy

Interaction between carcinoma-associated fibroblasts (CAFs) and tumor cells leads to the invasion and metastasis of breast cancer. Herein, we prepared a redox-responsive chondroitin sulfate (CS)-based nanomedicine, in which hydrophobic cabazitaxel (CTX) was conjugated to the backbone of CS via glutathione (GSH)-sensitive dithiomaleimide (DTM) to form an amphipathic CS-DTM-CTX (CDC) conjugate, and dasatinib (DAS) co-assembled with the CDC conjugate to obtain DAS@CDC. After CD44 receptor-mediated internalization by CAFs, the nanomedicine could reverse CAFs to normal fibroblasts, blocking their crosstalk with tumor cells and reducing synthesis of major tumor extracellular matrix proteins, including collagen and fibronectin. Meanwhile, the nanomedicine internalized by tumor cells could effectively inhibit tumor proliferation and metastasis, leading to shrinkage of the tumor volume and inhibition of lung metastasis in a subcutaneous 4T1 tumor model with low side effects. Collectively, the nanomedicine showed a remarkably synergistic therapy effect against breast cancer by modulating tumor-stromal crosstalk.

Maleimide-Functionalized Liposomes: Prolonged Retention and Enhanced Efficacy of Doxorubicin in Breast Cancer with Low Systemic Toxicity

Cell surface thiols can be targeted by thiol-reactive groups of various materials such as peptides, nanoparticles, and polymers. Here, we used the maleimide group, which can rapidly and covalently conjugate with thiol groups, to prepare surface-modified liposomes (M-Lip) that prolong retention of doxorubicin (Dox) at tumor sites, enhancing its efficacy. Surface modification with the maleimide moiety had no effect on the drug loading efficiency or drug release properties. Compared to unmodified Lip/Dox, M-Lip/Dox was retained longer at the tumor site, it was taken up by 4T1 cells to a significantly greater extent, and exhibited stronger inhibitory effect against 4T1 cells. The in vivo imaging results showed that the retention time of M-Lip at the tumor was significantly longer than that of Lip. In addition, M-Lip/Dox also showed significantly higher anticancer efficacy and lower cardiotoxicity than Lip/Dox in mice bearing 4T1 tumor xenografts. Thus, the modification strategy with maleimide may be useful for achieving higher efficient liposome for tumor therapy.

Chondroitin sulfate-based prodrug nanoparticles enhance photodynamic immunotherapy via Golgi apparatus targeting

Photodynamic therapy (PDT) is an emerging therapeutic approach that can inhibit tumor growth by destroying local tumors and activating systemic antitumor immune responses. However, PDT can be ineffective because of photosensitizer aggregation, tumor-induced dendritic cells (DC_S) dysfunction and PDT-mediated immunosuppression. Therefore, we designed chondroitin sulfate-based prodrug nanoparticles for the co-delivery of the photosensitizer chlorin e6 (Ce6) and retinoic acid (RA), which can reduce PDT-mediated immunosuppression by disrupting the Golgi apparatus and blocking the production of immunosuppressive cytokines. Moreover, CpG oligodeoxynucleotide was combined as immunoadjuvant to promote the maturation of DCs. As expected, the strategy of Golgi apparatus targeting immunotherapy combined PDT was confirmed to relieve PDT-induced immunosuppression, showed excellent PDT antitumor efficacy in B16F10-subcutaneous bearing mice model. Thus, our finding offers a promising approach for photodynamic immunotherapy of advanced cancers. STATEMENT OF SIGNIFICANCE: Golgi apparatus has been shown to be a potential target of immunosuppression for producing several immunosuppressive cytokines. In this work, a Golgi apparatus-targeted prodrug nanoparticle was developed to enhance the immune response in photodynamic immunotherapy. The nanoparticle can target and disrupt the Golgi apparatus in tumor cells, which reduced PDT-mediated immunosuppression by blocking the production of immunosuppressive cytokines. This work provides an effective strategy of PDT in combination with the Golgi apparatus-targeted nanovesicle for enhanced cancer therapy.

pH-responsive and CD44-targeting polymer micelles based on CD44p-conjugated amphiphilic block copolymer PEG-b-HES-b-PLA for delivery of emodin to breast cancer cells

Herein, an amphiphilic block copolymer CD44-targeting peptide-conjugated polyethylene glycol-block-hydroxyethyl starch-block-poly (L-lactic acid) (CD44p-conjugated PEG-b-HES-b-PLA) are synthesized, which could self-assemble into the pH-responsive and CD44-targeting polymer micelles against breast cancer cells MDA-MB-231. Emodin (Emo) is a natural anthraquino with pharmacological activities in anti-tumor effects. However, Emo suffers from poor water solubility, low biocompatibility, rapid systemic elimination, and off-target side effects, resulting in unsatisfactory treatment outcomes. Nanotechnology-based drug delivery systems have proven great potential for cancer chemotherapy. The constructed polymeric micelles Emo@CD44p-PM have exhibited an average size of 154.5 ± 0.9 nm characterized by DLS and TEM. Further, the Emo@CD44p-PM have effective Emo-loading capacity, good thermal stability, and pH responsiveness. Intracellular uptake study shows the enhanced cellular internalization of Emo@CD44p-PM due to the increased exposure of CD44p enhances the cellular internalization of Emo@CD44p-PM effectively. Furthermore, thein vitroresults showed Emo@CD44p-PM has been observed good biocompatibility and anti-tumor effects. Therefore, the polymeric micelles Emo@CD44p-PM provide a promising delivery strategy of targeted therapy for breast cancer.

CD44-Targeted Nanocarrier for Cancer Therapy

Cluster of differentiation 44 (CD44) is a cell surface glycoprotein overexpressed in varieties of solid tumors including pancreatic, breast, ovary, brain, and lung cancers. It is a multi-structural glycoprotein of the cell surface which is majorly involved in cell proliferation, cell-to-cell interaction, cellular migration, inflammation, and generation of immune responses. Numerous studies focus on the development of nanocarriers for active targeting of the CD44 receptor to improve efficacy of targeting chemotherapy and achieve precise chemotherapy by defining the release, uptake, and accumulation of therapeutic agents. The CD44 receptor has a selective binding affinity towards hyaluronic and chondroitin sulfate (CS). Taking this into consideration, this review focused on the role of CD44 in cancer and its therapy using several nanocarriers such as polymeric/non-polymeric nanoparticles, dendrimer, micelles, carbon nanotubes, nanogels, nanoemulsions etc., for targeted delivery of several chemotherapeutic molecules and nucleic acid. This review also illuminates the role of hyaluronic acid (HA) in cancer therapy, interaction of HA with CD44, and various approaches to target CD44-overexpressed neoplastic cells.

Multifunctional Mitochondria-Targeting Nanosystems for Enhanced Anticancer Efficacy

Mitochondria, a kind of subcellular organelle, play crucial roles in cancer cells as an energy source and as a generator of reactive substrates, which concern the generation, proliferation, drug resistance, and other functions of cancer. Therefore, precise delivery of anticancer agents to mitochondria can be a novel strategy for enhanced cancer treatment. Mitochondria have a four-layer structure with a high negative potential, which thereby prevents many molecules from reaching the mitochondria. Luckily, the advances in nanosystems have provided enormous hope to overcome this challenge. These nanosystems include liposomes, nanoparticles, and nanomicelles. Here, we summarize the very latest developments in mitochondria-targeting nanomedicines in cancer treatment as well as focus on designing multifunctional mitochondria-targeting nanosystems based on the latest nanotechnology.

Eight-lncRNA signature of cervical cancer were identified by integrating DNA methylation, copy number variation and transcriptome data

BACKGROUND

Copy number variation (CNV) suggests genetic changes in malignant tumors. Abnormal expressions of long non-coding RNAs (lncRNAs) resulted from genomic and epigenetic abnormalities play a driving role in tumorigenesis of cervical cancer. However, the role of lncRNAs-related CNV in cervical cancer remained largely unclear.

METHODS

The data of messenger RNAs (mRNAs), DNA methylation, and DNA copy number were collected from 292 cervical cancer specimens. The prognosis-related subtypes of cervical cancer were determined by multi-omics integration analysis, and protein-coding genes (PCGs) and lncRNAs with subtype-specific expressions were identified. The CNV pattern of the subtype-specific lncRNAs was analyzed to identify the subtype-specific lncRNAs. A prognostic risk model based on lncRNAs was established by least absolute shrinkage and selection operator (LASSO).

RESULTS

Multi-omics integration analysis identified three molecular subtypes incorporating 617 differentially expressed lncRNAs and 1395 differentially expressed PCGs. The 617 lncRNAs were found to intersect with disease-related lncRNAs. Functional enrichment showed that 617 lncRNAs were mainly involved in tumor metabolism, immunity and other pathways, such as p53 and cAMP signaling pathways, which are closely related to the development of cervical cancer. Finally, according to CNV pattern consistent with differential expression analysis, we established a lncRNAs-based signature consisted of 8 lncRNAs, namely, RUSC1-AS1, LINC01990, LINC01411, LINC02099, H19, LINC00452, ADPGK-AS1, C1QTNF1-AS1. The interaction of the 8 lncRNAs showed a significantly poor prognosis of cervical cancer patients, which has also been verified in an independent dataset.

CONCLUSION

Our study expanded the network of CNVs and improved the understanding on the regulatory network of lncRNAs in cervical cancer, providing novel biomarkers for the prognosis management of cervical cancer patients.

Redox-responsive nanoparticles based on Chondroitin Sulfate and Docetaxel prodrug for tumor targeted delivery of Docetaxel

In this paper, a novel redox-responsive nanoparticles has been designed for targeted delivery of docetaxel (DTX). Chondroitin sulfate (CS) was used to construct the nanoparticles due to the ability of tumor targeting through binding with CD44 receptor that overexpresses on the surfaces of various tumor cells. A redox-responsive small-molecular DTX prodrug was prepared through modifying with cystamine containing disulfide bonds (Cys-DTX). Then the DTX prodrug was grafted to the CS to construct the amphiphilic polymer (CS-ss-DTX). Further, Cys-DTX/CS-ss-DTX nanoparticles were formed by self-assembly of amphiphilic polymer and incorporation of free Cys-DTX prodrug. This category of nanosized DTX delivery system was expected for not only exhibiting high permeability and cytotoxicity of Cys-DTX prodrug, but also targeting transportation of encapsulated redox-responsive Cys-DTX prodrug. According to results of related researches on physicochemical properties and biological evaluation, the novel redox-responsive Cys-DTX/CS-ss-DTX nanoparticles increased amount of DTX released from the nanoparticles in reductive environment, improved permeability in tumor tissues, enhanced cytotoxicity and decreased side effects compared with free DTX. All of these results showed that this kind of Cys-DTX/CS-ss-DTX nanoparticles were worthy of being expectation in tumor chemotherapy in future.

Chondroitin sulfate-hybridized zein nanoparticles for tumor-targeted delivery of docetaxel

Chondroitin sulfate-hybridized zein nanoparticles (zein/CS NPs) were developed for targeted delivery of docetaxel, which exhibited mean diameters of 157.8 ± 3.6 nm and docetaxel encapsulation efficiency of 64.2 ± 1.9 %. Docetaxel was released from the NPs in a sustained manner (∼72 h), following first-order kinetics. The zein/CS NPs showed improved colloidal stability, maintaining the initial size in serum for 12 h. The pre-treatment of CS reduced the uptake efficiency of the NPs by 23 % in PC-3 cells, suggesting the involvement of CD44-mediated uptake mechanism. The NPs showed 2.79-fold lower IC₅₀ values than free docetaxel. Enhanced tumor accumulation of the NPs was confirmed in PC-3 xenograft mice by near-infrared fluorescence imaging (35.3-fold, versus free Cy5.5). The NPs exhibited improved pharmacokinetic properties (9.5-fold longer terminal half-life, versus free docetaxel) and anti-tumor efficacy comparable to Taxotere with negligible systemic toxicity, suggesting zein/CS NPs could be a promising nanoplatform for targeted cancer therapy.

Drug delivery systems based on CD44-targeted glycosaminoglycans for cancer therapy

The polysaccharide-based biomaterials hyaluronic acid (HA) and chondroitin sulfate (CS) have aroused great interest for use in drug delivery systems for tumor therapy, as they have outstanding biocompatibility and great targeting ability for cluster determinant 44 (CD44). In addition, modified HA and CS can self-assemble into micelles or micellar nanoparticles (NPs) for targeted drug delivery. This review discusses the formation of HA- and CS-based NPs, and various types of CS-based NPs including CS-drug conjugates, CS-polymer NPs, CS-small molecule NPs, polyelectrolyte nanocomplexes (PECs), CS-metal NPs, and nanogels. We then focus on the applications of HA- and CS-based NPs in tumor chemotherapy, gene therapy, photothermal therapy (PTT), photodynamic therapy (PDT), sonodynamic therapy (SDT), and immunotherapy. Finally, this review is expected to provide guidelines for the development of various HA- and CS-based NPs used in multiple cancer therapies.

Docetaxel-Loaded Chitosan-Cholesterol Conjugate-Based Self-Assembled Nanoparticles for Overcoming Multidrug Resistance in Cancer Cells

Cholesteryl hemisuccinate (CHS)-conjugated chitosan (CS)-based self-assembled nanoparticles (NPs) were developed for enhancing the intracellular uptake of docetaxel in multidrug resistance (MDR)-acquired cancer cells. CHS-CS was successfully synthesized and self-aggregation, particle size, zeta potential, drug entrapment efficiency, and in vitro drug release of docetaxel-loaded CHS-CS NPs were tested. The optimized NPs had a mean hydrodynamic diameter of 303 nm, positive zeta potential of 21.3 mV, and spherical shape. The in vitro release of docetaxel from the optimized CHS-CS NPs in different pH medium (pH 6.0 and 7.4) revealed that the release was improved in a more acidic condition (pH 6.0), representing a tumor cell's environment. The superior MDR-overcoming effect of docetaxel-loaded CHS-CS NPs, compared with docetaxel solution, was verified in anti-proliferation and cellular accumulation studies in MDR-acquired KBV20C cells. Thus, CHS-CS NPs could be potentially used for overcoming the MDR effect in anticancer drug delivery.