Antitumor Drug Delivery Research Articles

Symmetric Diblock Copolymers Form Versatile and Switchable Ultrasmall Nanoparticles.

Block copolymers (BCPs) can form nanoparticles having different morphologies that can be used as photonic nanocrystals and are a platform for drug delivery, sensors, and catalysis. In particular, BCP nanoparticles having disk-like shape have been recently discovered. Such nanodisks can be used as the next-generation antitumor drug delivery carriers; however, the applicability of the existing nanodisks is limited due to their poor or unknown ability to respond to external stimuli. In this work, we showed that the simplest symmetric diblock copolymers in equilibrium can form nanodisks that can be reversibly switched into a multitude of various nanoparticles potentially applicable in nanophotonics, biomedicine, and hierarchical self-assembly. These structures include patchy and onion-like nanoparticles, striped ellipsoids, mixed morphology nanocolloids, and spherical micelles. The transitions between nanodisks and the aforementioned nanoparticles are sharp, direct, and can be achieved by tuning the block-block and polymer-solvent incompatibility. We demonstrated that this versatility of nanoparticle morphologies can be achieved upon reducing the nanoparticle size to approximately two lamellar periods of the BCP. Upon aggregation of such small nanocolloids, a larger assembly can be formed. In turn, these bigger particles could form many other structures including a chain-like supramolecular aggregate of nanodisks and a multilayered disk-like nanoparticle. We obtained our results by performing self-consistent field theory calculations according to an algorithm designed to produce equilibrium nanoparticle morphology. This work demonstrates that nanodisks prepared from the simplest type of BCPs are extremely tunable; therefore, symmetric diblock copolymers can become a platform for producing the next-generation stimuli-responsive nanoparticles.

Research progress of liposome drug delivery system in the treatment of head and neck cancer

Head and neck tumors are one of the major diseases that threaten human health. Targeted chemotherapy is an important treatment for head and neck tumors. However, many anti-cancer drugs are difficult to reach effective concentrations in tumors and can cause damage to normal tissues. Therefore, the efficient delivery of anti-tumor drugs, improvement of their therapeutic effects, and reduction of their adverse effects on the whole body and locally are urgent issues in targeted drug research. Liposomes have been widely studied due to their unique characteristics, including amphiphilicity, biocompatibility, biodegradability, and low toxicity. This article outlines the current applications and prospects of liposome drug delivery systems in different treatment modalities for head and neck tumors in recent years, aiming to provide more options for the treatment of head and neck tumors.

Folic Acid-Targeted Mixed Pluronic Micelles for Delivery of Triptolide.

The present study aimed to explore an ideal delivery system for triptolide (TPL) by utilizing the thin-film hydration method to prepare drug-loaded, folate-modified mixed pluronic micelles (FA-F-127/F-68-TPL). Scanning electron microscopy and atomic force microscopy showed that the drug-loaded micelles had a spherical shape with a small particle size, with an average of 30.7 nm. Cell viability experiments showed that FA-F-127/F-68-TPL significantly reduced HepG2 cell viability, exhibiting strong cytotoxicity. Its cytotoxicity was markedly enhanced compared with bare TPL. Nile red (Nr) was used as a model drug to prepare FA-F-127/F-68-Nr to further validate its tumor-targeting and cellular uptake capability. After coincubation with HepG2 cells, a multifunctional microplate reader showed that intracellular fluorescence intensity significantly increased, indicating that FA-F-127/F-68-Nr could more effectively enter the cells. A nude mouse model of subcutaneous hepatocellular carcinoma was constructed. Following tail vein injection of FA-F-127/F-68-Nr, the fluorescence imaging system showed that FA-F127/F-68-Nr could significantly target tumor tissue, and even if entering the small-sized tumor was challenging, it could be excreted through urine. Nude mice with subcutaneous hepatocellular carcinoma were treated with tail vein injections of FA-F-127/F-68-TPL (45 µg/kg) every other day for 21 days. The results showed that the growth of the transplanted tumors was significantly slowed, with no significant difference compared with bare TPL. In summary, the FA-F-127/F-68-TPL exhibits the advantages of low cost, excellent biological properties, active/passive targeting capabilities, notable cytotoxicity against liver cancer cells, and significant inhibition of transplanted hepatocellular carcinoma growth. Significantly, the FA-F-127/F-68-TPL, despite challenges in targeting tumors with an insignificant EPR effect, can be efficiently excreted via the kidneys, thereby preventing the release of the drug during prolonged circulation and potential damage to normal tissues. Therefore, FA-F-127/F-68-TPL represents a promising antitumor drug delivery system.

Advances in the application of live bacteria as vehicles for delivering antitumor drugs

Some bacteria can selectively colonize the tumor site and inhibit tumor growth, serving as ideal vehicles for delivering antitumor drugs. The system of delivering antitumor drugs with live bacteria as vehicles is characterized by good biocompatibility and precise targeting. However, the development of bacteria as drug delivery vehicles is limited by their own immunogenicity. In this paper, the selection of chassis bacteria, bacterial loading drug strategies, antitumor drug delivery applications and their limitations are elaborated in detail, and its future development direction is envisioned, with a view to providing a reference for the study of live bacteria as antitumor drug delivery carriers.

Oral and tumor-targeting mixed micelles based on pegylated biotin and chitosan-based conjugate for breast cancer treatment

Oral drug delivery with tumor-targeting treatment persists as a challenge. In this study, a mixed polymeric micelle (PM) delivery system was designed to overcome the barriers to oral administration for tumor-targeting delivery of paclitaxel (PTX) for breast cancer treatment. D-α-Tocopheryl polyethylene glycol 1000 succinate-modified carboxymethyl chitosan-rhein (TCR) conjugate and Biotin-polyethylene glycol 2000-Biotin (BPB) conjugate were mixed to form TCR-BPB PMs. The particle size and polydispersity index of optimized PTX-loaded TCR-BPB PMs (PTX/TCR-BPB PMs) was 195.90 ± 7.63 nm and 0.08 ± 0.00, with a drug-loading capacity of 41.94 ± 2.47 %. In simulated gastroenteric fluid and blood environments, the PMs presented a sustained-release manner. PTX/TCR-BPB PMs were taken up by Caco-2 and 4T1 cells and displayed strong cytotoxicity in a time- and concentration-dependent manner. PTX/TCR-BPB PMs significantly improved intestinal absorption of PTX. The pharmacokinetics, tissue distribution, and in vivo imaging indicated that PTX/TCR-BPB PMs could enhance oral bioavailability of PTX, prolong the retention time of PTX in the blood, and enhance PTX tumor-targeting ability. PTX/TCR-BPB PMs enhance the antitumor efficacy of PTX and reduce its toxicity in normal organs. Therefore, TCR-BPB PMs are expected to serve as delivery carriers for the oral and tumor-targeting delivery of hydrophobic antitumor drugs.

Molecular mechanism of enhancing antitumor activity through the interaction between monosaccharides and human serum albumin.

This study investigated the molecular mechanisms of the interactions between three antitumor active monosaccharides and human serum albumin (HSA) using spectroscopic and electrochemical analyses, supplemented by molecular docking simulations. The antitumor efficacy of these monosaccharides can be significantly enhanced by covalent drug coupling, while HSA, with its long half-life and low immunogenicity, provides new opportunities for the development of advanced antitumor drug delivery systems. The results showed that these monosaccharides effectively burst the fluorescence of HSA. Thermodynamic analysis revealed that Fucose undergoes a spontaneous, exothermic process that decreases entropy, while the binding of Mannose and Galactose is entropy-driven. Notably, the addition of these three monosaccharides slightly compacts the structure of HSA, stabilizing its transport and delivery in vivo, with the binding strength categorized as Fucose > Mannose > Galactose. These variations in binding constants explain the differences in efficacy and potential side effects in antitumor therapy. Further studies have shown that the interaction between monosaccharides and HSA improves drug stability and targeting, thereby enhancing antitumor activity. An in-depth study of these interactions may provide new insights into the design and optimization of antitumor drugs and the further development of novel antitumor therapies.

Dual role of triglyceride structures facilitates anti-tumor drug delivery: Both as a self-assembling module and a responsive module

Small molecule prodrugs self-assembled nano-delivery systems with tumor responsive linkages are emerging as an effective platform. However, the heterogeneity of tumor microenvironment may limit the anti-tumor effect of prodrug nanomedicines with a single response module. Here, we chose disulfide bond as the response module and branched chain alcohol as the self-assembly modification module to construct a single-responsive prodrug. We also constructed a double-responsive paclitaxel prodrug combining triglyceride and disulfide bond, taking into account of the highly expressed lipase and glutathione levels in tumor cells. The results showed that the anti-tumor effect of single-responsive branched chain alcohol modified prodrug nanoparticles was inferior to triglyceride prodrug nanoparticles with dual response modules. The triglyceride structure can not only serve as a self-assembly modification module, but also serve as a response module for intelligent drug release in tumor. Such dual roles will facilitate the efficient delivery of small molecule self-assembled prodrugs to tumor sites.

Construction of anticancer drug incorporated aptamer-functionalized cationic β-lactoglobulin: induction of cell cycle arrest and apoptosis in colorectal cancer

Nanoscale drug delivery systems that are both multifunctional and targeted have been developed using proteins as a basis, thanks to their attractive biomacromolecule properties. A novel nanocarrier, aptamer (AS1411)-conjugated β-lactoglobulin/poly-l-lysine (BLG/Ap/PL) nanoparticles, was developed in this study. To this unique formulation, the as-prepared nanocarrier blends the distinctive features of an aptamer as a chemotherapeutic targeting agent with those of protein nanocarriers. By loading cabazitaxel (CTX) onto the nanocarriers, the therapeutic potential of BLG/Ap/PL could be demonstrated. The CTX-loaded BLG/Ap/PL (CTX@BLG/Ap/PL) showed a regulated drug release profile in an acidic milieu, which could improve therapeutic efficacy in cancer cells and have a high drug encapsulation efficacy of up to 93%. However, compared to free CTX, CTX@BLG/Ap/PL killed colorectal HCT116 cancer cells with a higher efficacy at 24 and 48 h. Further investigation confirms the apoptosis by acridine orange and ethidium bromide (AO/EB), and DAPI staining confirms the morphological changes, chromatin condensation, and membrane blebbing in the treated cell through flow cytometry displayed the release of higher percentages of apoptosis. Cell cycle analysis revealed that CTX@BLG/Ap/PL induced sub-G1 and G2/M phase (apoptosis) at 24 and 48 h. Annexin V/propidium iodide (PI) flow cytometry analysis confirmed that CTX@BLG/Ap/PL induces apoptosis in HCT116 cells. Overall, this study proved that CTX@BLG/Ap/PL had several advantages over free chemotherapeutic drugs and showed promise as a solution to the clinical problems associated with targeted antitumor drug delivery systems.

Fiber-optic drug delivery strategy for synergistic cancer photothermal-chemotherapy

Chemotherapy is one of the conventional treatments for cancer in clinical practice. However, poor delivery efficiency, systemic toxicity, and the lack of pharmacokinetic monitoring during treatment are the critical limitations of current chemotherapy. Herein, we reported a brand-new antitumor drug delivery strategy that harnesses an optical fiber endoscopically therapeutic probe. The fiber probe carries photosensitizers in the fiber core and antitumor agents on the fiber surface mediated by a temperature-responsive hydrogel film, giving rise to an activable photothermal-chemotherapy that orchestrates the localized hyperthermia and thermal-stimuli drug release to the tumor lesion. Furthermore, the dynamical drug release and in-situ temperature can be real-time supervised through the built-in fiber sensors, including the reflective Mach–Zehnder interferometer and fiber Bragg grating, to visualize the therapy process and thus improve the safety of treatment. Compared with conventional methods, the fiber-optic drug delivery can adequately take advantage of the chemotherapeutics through collaboratively recruiting the photoheating-mediated enhanced permeability and the hydrogel particle-assisted high drug retention, shedding new light on a “central-to-peripheral” drug pervasion and retention mechanism to destroy tumors completely. The fiber-optic chemotherapy strategy incorporates precise drug delivery, accurate controllability of drug release, high drug permeability and retention in tumor, low off-target rate, and real-time drug release and temperature feedback, performing a straightforward and precise photothermal-chemotherapy pathway. More than that, the proposed strategy holds tremendous promise to provide a revolutionized on-demand drug delivery platform for the highly efficient evaluation and screening of antitumor pharmaceuticals.

Evaluation of 3-O-β-D-galactosylated resveratrol-loaded polydopamine nanoparticles for hepatocellular carcinoma treatment

In our previous studies, 3-O-β-D-galactosylated resveratrol (Gal-Res) was synthesized by structural modification and then 3-O-β-D-galactosylated resveratrol polydopamine nanoparticles (Gal-Res NPs) were successfully prepared to improve the bioavailability and liver distribution of Res. However, the pharmacodynamic efficacy and specific mechanism of Gal-Res NPs on hepatocellular carcinoma remain unclear. Herein, liver cancer model mice were successfully constructed by xenograft tumor modeling. Gal-Res NPs (34.2 mg/kg) significantly inhibited tumor growth of the liver cancer model mice with no significant effect on their body weight and no obvious toxic effect on major organs. Additionally, in vitro cellular uptake assay showed that Gal-Res NPs (37.5 μmol/L) increased the uptake of Gal-Res by Hepatocellular carcinoma (HepG2) cells, and significantly inhibited the cell migration and invasion. The experimental results of Hoechst 33342/propyl iodide (PI) double staining and flow cytometry both revealed that Gal-Res NPs could remarkably promote cell apoptosis. Moreover, the Western blot results revealed that Gal-Res NPs significantly regulated the Bcl-2/Bax and AKT/GSK3β/β-catenin signaling pathways. Taken together, the in vitro/in vivo results demonstrated that Gal-Res NPs significantly improved the antitumor efficiency of Gal-Res, which is a potential antitumor drug delivery system.

αvβ3 Integrin and Folate-Targeted pH-Sensitive Liposomes with Dual Ligand Modification for Metastatic Breast Cancer Treatment.

The advent of pH-sensitive liposomes (pHLips) has opened new opportunities for the improved and targeted delivery of antitumor drugs as well as gene therapeutics. Comprising fusogenic dioleylphosphatidylethanolamine (DOPE) and cholesteryl hemisuccinate (CHEMS), these nanosystems harness the acidification in the tumor microenvironment and endosomes to deliver drugs effectively. pH-responsive liposomes that are internalized through endocytosis encounter mildly acidic pH in the endosomes and thereafter fuse or destabilize the endosomal membrane, leading to subsequent cargo release into the cytoplasm. The extracellular tumor matrix also presents a slightly acidic environment that can lead to the enhanced drug release and improved targeting capabilities of the nano-delivery system. Recent studies have shown that folic acid (FA) and iRGD-coated nanocarriers, including pH-sensitive liposomes, can preferentially accumulate and deliver drugs to breast tumors that overexpress folate receptors and αvβ3 and αvβ5 integrins. This study focuses on the development and characterization of 5-Fluorouracil (5-FU)-loaded FA and iRGD surface-modified pHLips (FA-iRGD-5-FU-pHLips). The novelty of this research lies in the dual targeting mechanism utilizing FA and iRGD peptides, combined with the pH-sensitive properties of the liposomes, to enhance selective targeting and uptake by cancer cells and effective drug release in the acidic tumor environment. The prepared liposomes were small, with an average diameter of 152 ± 3.27 nm, uniform, and unilamellar, demonstrating efficient 5-FU encapsulation (93.1 ± 2.58%). Despite surface functionalization, the liposomes maintained their pH sensitivity and a neutral zeta potential, which also conferred stability and reduced aggregation. Effective pH responsiveness was demonstrated by the observation of enhanced drug release at pH 5.5 compared to physiological pH 7.4. (84.47% versus 46.41% release at pH 5.5 versus pH 7.4, respectively, in 72 h). The formulations exhibited stability for six months and were stable when subjected to simulated biological settings. Blood compatibility and cytotoxicity studies on MDA-MB-231 and SK-BR3 breast cancer cell lines revealed an enhanced cytotoxicity of the liposomal formulation that was modified with FA and iRGD compared to free 5-FU and minimal hemolysis. Collectively, these findings support the potential of FA and iRGD surface-camouflaged, pH-sensitive liposomes as a promising drug delivery strategy for breast cancer treatment.

Biohybrid hydrogel inhibiting β-klotho/HDAC3 axis for hepatocellular carcinoma treatment

Hepatocellular carcinoma (HCC), ranking as the fourth most prevalent cancer globally, has garnered significant attention due to its high invasiveness and mortality rates. However, drug therapies face challenges of inadequate efficacy and unclear mechanisms. Here, we propose a novel biohybrid hydrogel that targets β-klotho (KLB) for HCC treatment. As a dual-network hydrogel, this gel combines gelatin methacryloyl (GelMA) and polyvinyl alcohol (PVA) to ensure biocompatibility while enhancing controlled drug release. Notably, it exhibits good storage stability, high drug load capacity, and efficient water absorption. By introducing the HDAC3 inhibitor RGFP966, we can selectively inhibit the activation of KLB. This deactivation effectively blocks the FGF21-KLB signaling pathway and inhibits the progression of HCC. Importantly, we have successfully validated this unique phenomenon both in vivo and in vitro, providing substantial evidence for the efficacy of this hydrogel-based anti-tumor drug delivery system as a promising strategy for HCC treatment. This innovative research outcome brings new hope to the field of tumor therapy, providing a reliable theoretical foundation for future clinical applications.

Research Progress of Disulfide Bond Based Tumor Microenvironment Targeted Drug Delivery System.

Cancer poses a significant threat to human life and health. Chemotherapy is currently one of the effective cancer treatments, but many chemotherapy drugs have cell toxicity, low solubility, poor stability, a narrow therapeutic window, and unfavorable pharmacokinetic properties. To solve the above problems, target drug delivery to tumor cells, and reduce the side effects of drugs, an anti-tumor drug delivery system based on tumor microenvironment has become a focus of research in recent years. The construction of a reduction-sensitive nanomedicine delivery system based on disulfide bonds has attracted much attention. Disulfide bonds have good reductive responsiveness and can effectively target the high glutathione (GSH) levels in the tumor environment, enabling precise drug delivery. To further enhance targeting and accelerate drug release, disulfide bonds are often combined with pH-responsive nanocarriers and highly expressed ligands in tumor cells to construct drug delivery systems. Disulfide bonds can connect drug molecules and polymer molecules in the drug delivery system, as well as between different drug molecules and carrier molecules. This article summarized the drug delivery systems (DDS) that researchers have constructed in recent years based on disulfide bond drug delivery systems targeting the tumor microenvironment, disulfide bond cleavage-triggering conditions, various drug loading strategies, and carrier design. In this review, we also discuss the controlled release mechanisms and effects of these DDS and further discuss the clinical applicability of delivery systems based on disulfide bonds and the challenges faced in clinical translation.

Dual Reduction-Sensitive Nanomicelles for Antitumor Drug Delivery with Low Toxicity to Normal Cells

Dual Reduction-Sensitive Nanomicelles for Antitumor Drug Delivery with Low Toxicity to Normal Cells

Development of receptor-targeted and pH-responsive zeolitic imidazole framework-90 nanoplatform for anti-ovarian cancer

The covalent functionalization of the zeolitic imidazolate framework (ZIF) is rapidly progressing and is being exploited as a nanoplatform for antitumor drug delivery to improve tumor targeting and drug release. Here, a novel nanoplatform strategy was developed by encapsulating Carboplatin (CBP) in ZIF-90 nanospheres (NPs) to obtain CBP@ZIF-90 NPs and then, modifying folate-terminated methoxypoly(ethylene glycol) (FA-PEG-NH2) on the aldehyde group of ZIF-90 to form CBP@ZIF-90-NPF NPs with acid-sensitive Schiff base bond. The research results indicate that the yield of ZIF-90 was 72.77 ± 0.27 %, and the encapsulation efficiency and the loading content of CBP@ZIF-90 were 45.22 ± 0.49 % and 24.65 ± 0.34 %, respectively. The size of CBP@ZIF-90-NPF was 107.7 ± 1.7 nm in monodispersity with a single crystalline dodecahedral structure. Furthermore, the in vitro release behavior study revealed the sustained-release and the pH-responsive dissociation properties of the NPs. Only 6.84 % of CBP was released from the nanocarrier under physiological pH conditions for 48 h, while the release from the tumor microenvironment was 92.89 %. In addition, the cellular uptake result clearly showed that most of the FA-PEG-NH2 modified NPs exhibited specific selectivity in tumor cell nuclei. Finally, the cell counting kit-8 (CCK8) assay based on human ovarian cancer cell line (OVCAR-3) and human normal ovarian epithelial (IOSE-80) cell line obviously indicated that the ZIF-90 NPs had good biocompatibility and minimal cytotoxicity, as well as the high inhibition efficiency of the CBP@ZIF-90-NPF NPs meant that a much higher amount of CBP was transferred into the folate receptor (FR)-overexpressed ovarian cancer cells via FR mediated endocytosis. These results suggest that ZIF-90-NPF NPs could be an ideal targeted drug delivery vehicle for CBP, serving as a promising strategy for ovarian cancer treatment.

Applications of nanomaterials in medicine against cancer

Nowadays, all walks of life are developing with innovation at their core, and the subject of materials is no exception, while nanomaterials occupy an important position in the emerging field due to their unique properties and wide coverage. In addition, the incidence of cancer, a difficult disease with a very high mortality rate, is increasing day by day. Therefore, research on cancer has received extensive attention from society. Therefore, this paper explores how cancer can be treated by means of nanomaterials through the organization of current research and papers in the field. Research at this stage suggests that nanomaterials play a major auxiliary role in anti-cancer technology, as follows: enhancing the ability of other substances to disrupt cell membranes, assisting in the delivery of anti-tumor drugs, improving imaging capabilities, and enhancing the ability of some substances to inhibit tumor growth through specific mechanisms. In future research, the focus will be on minimizing the side effects of the treatment and improving its safety.

Biodegradable chitin nanofiber-alginate dialdehyde hydrogel: An injectable, self-healing scaffold for anti-tumor drug delivery

Injectable hydrogels fabricated from natural polymers have attracted increasing attentions for their potential in biomedical application owing to the biocompatibility and biodegradability. A new class of natural polymer based self-healing hydrogel is constructed through dynamic covalent bonds. The injectable self-healing hydrogels are fabricated by introducing alginate aldehyde to form Schiff base bonds with the chitin nanofibers. These hydrogels demonstrate excellent self-healing properties, injectability, and pH-responsive sol-gel transition behaviors. As a result, they can serve as carriers to allow an effective encapsulation of doxorubicin (DOX) for drug delivery. Furthermore, these hydrogels exhibit excellent biocompatibility and degradability in vitro and in vivo. The sustained release of DOX from the hydrogels effectively suppresses tumor growth in animal models without causing significant systemic toxicity, suggesting their potential application in anti-tumor therapies.

Towards a More Efficient Breast Cancer Therapy Using Active Human Cell Membrane-Coated Metal–Organic Frameworks

The recent description of well-defined molecular subtypes of breast cancer has led to the clinical development of a number of successful molecular targets. Particularly, triple-negative breast cancer (TNBC) is an aggressive type of breast cancer with historically poor outcomes, mainly due to the lack of effective targeted therapies. Recent progresses in materials science have demonstrated the impressive properties of metal–organic framework nanoparticles (NPs) as antitumoral drug delivery systems. Here, in a way to achieve efficient bio-interfaces with cancer cells and improve their internalization, benchmarked MIL-100(Fe) NPs were coated with cell membranes (CMs) derived from the human TNBC cell line MDA-MB-468. The prepared CMs-coated metal–organic framework (CMs_MIL-100(Fe)) showed enhanced colloidal stability, cellular uptake, and cytotoxicity in MDA-MB-468 cells compared to non-coated NPs, paving the way for these human CMs-coated MIL-100(Fe) NPs as effective targeted therapies against the challenging TNBC.

Development of 5-Fluorouracil/pH-Responsive Adjuvant-Embedded Extracellular Vesicles for Targeting αvβ3 Integrin Receptors in Tumors.

To selectively target and treat murine melanoma B16BL6 tumors expressing αvβ3 integrin receptors, we engineered tumor-specific functional extracellular vesicles (EVs) tailored for the targeted delivery of antitumor drugs. This objective was achieved through the incorporation of a pH-responsive adjuvant, cyclic arginine-glycine-aspartic acid peptide (cRGD, serving as a tumor-targeting ligand), and 5-fluorouracil (5-FU, employed as a model antitumor drug). The pH-responsive adjuvant, essential for modulating drug release, was synthesized by chemically conjugating 3-(diethylamino)propylamine (DEAP) to deoxycholic acid (DOCA, a lipophilic substance capable of integrating into EVs' membranes), denoted as DEAP-DOCA. The DOCA, preactivated using N-(2-aminoethyl)maleimide (AEM), was chemically coupled with the thiol group of the cRGD-DOCA through the thiol-maleimide click reaction, resulting in the formation of cRGD-DOCA. Subsequently, DEAP-DOCA, cRGD-DOCA, and 5-FU were efficiently incorporated into EVs using a sonication method. The resulting tumor-targeting EVs, expressing cRGD ligands, demonstrated enhanced in vitro/in vivo cellular uptake specifically for B16BL6 tumors expressing αvβ3 integrin receptors. The ionization characteristics of the DEAP in DEAP-DOCA induced destabilization of the EVs membrane at pH 6.5 through protonation of the DEAP substance, thereby expediting 5-FU release. Consequently, an improvement in the in vivo antitumor efficacy was observed for B16BL6 tumors. Based on these comprehensive in vitro/in vivo findings, we anticipate that this EV system holds substantial promise as an exceptionally effective platform for antitumor therapeutic delivery.

Biological Roles and Clinical Applications of Exosomes in Breast Cancer: A Brief Review.

Breast cancer (BC) is a global health risk for women and has a high prevalence rate. The drug resistance, recurrence, and metastasis of BC affect patient prognosis, thus posing a challenge to scientists. Exosomes are extracellular vesicles (EVs) that originate from various cells; they have a double-layered lipid membrane structure and contain rich biological information. They mediate intercellular communication and have pivotal roles in tumor development, progression, and metastasis and drug resistance. Exosomes are important cell communication mediators in the tumor microenvironment (TME). Exosomes are utilized as diagnostic and prognostic biomarkers for estimating the treatment efficacy of BC and have the potential to function as tools to enable the targeted delivery of antitumor drugs. This review introduces recent progress in research on how exosomes influence tumor development and the TME. We also present the research progress on the application of exosomes as prognostic and diagnostic biomarkers and drug delivery tools.