Improved Antitumor Efficacy of a Dextran-based Docetaxel-coupled Conjugate against Triple-Negative Breast Cancer.

BACKGROUND: Most chemotherapeutic agents are characterized by poor water solubility and non-specific distribution. Polymer-based conjugates are promising strategies for overcoming these limitations. OBJECTIVE: This study aims to fabricate a polysaccharide, dextran-based, dual-drug conjugate by covalently grafting docetaxel (DTX) and docosahexaenoic acid (DHA) onto the bifunctionalized dextran through a long linker, and to investigate the antitumor efficacy of this conjugate against breast cancer. METHODS: DTX was firstly coupled with DHA and covalently bounded with the bifunctionalized dextran (100 kDa) through a long linker to produce a conjugate dextran-DHA-DTX (termed C-DDD). Cytotoxicity and cellular uptake of this conjugate were measured in vitro. Drug biodistribution and pharmacokinetics were investigated through liquid chromatography/mass spectrometry analysis. The inhibitory effects on tumor growth were evaluated in MCF-7- and 4T1-tumor-bearing mice. RESULTS: The loading capacity of the C-DDD for DTX was 15.90 (weight/weight). The C-DDD possessed good water solubility and was able to self-assemble into nanoparticles measuring 76.8 ± 5.5 nm. The maximum plasma concentration and area under the curve (0-∞) for the released DTX and total DTX from the C-DDD were significantly enhanced compared with the conventional DTX formulation. The C-DDD selectively accumulated in the tumor, with limited distribution was observed in normal tissues. The C-DDD exhibited greater antitumor activity than the conventional DTX in the triplenegative breast cancer model. Furthermore, the C-DDD nearly eliminated all MCF-7 tumors in nude mice without leading to systemic adverse effects. CONCLUSION: This dual-drug C-DDD has the potential to become a candidate for clinical application through the optimization of the linker.

Influence of unsaturated fatty acids on the antitumor activity of polymeric conjugates grafted with cabazitaxel against prostate cancer.

Cabazitaxel (CTX) is a medication used for treating metastatic prostate cancer. However, its effectiveness is majorly limited by its poor water solubility and lack of tumor targeting. In this study, three unsaturated fatty acids, GLA, ALA and DHA, were separately connected with CTX and then covalently attached to bifunctionalized dextran through a linker to produce three dual drug conjugates named dextran-GLA-CTX, dextran-ALA-CTX and dextran-DHA-CTX. The three conjugates displayed enhanced solubility of CTX in water and improved antitumor effects compared to the conventional CTX formulation. The results also confirmed that dextran-GLA-CTX exhibited the strongest antitumor activity, while dextran-DHA-CTX displayed less efficacy, as evaluated through xenografted nude mice bearing PC-3 and DU145 prostate cancer cells. Additionally, dextran-GLA-CTX showed greater inhibition of tumor growth than dextran-CTX. Moreover, the dextran-GLA-CTX conjugate was found to prolong the half-life of CTX in plasma and selectively accumulate in tumors. This study revealed that unsaturated fatty acids can enhance the antitumor activity of dextran-based conjugates grafted with CTX.

Polysaccharide dextran-based conjugate for selective co-delivery of two synergistic drugs docetaxel and docosahexaenoic acid to tumor cells.

Most chemotherapeutic agents are nonspecific distribution and cause systemic toxicities. Polysaccharide-based conjugates are promising strategies to overcome these drawbacks. To this end, two synergistic drugs docetaxel (DTX) and docosahexaenoic acid (DHA) were independently covalently bonded through individual linkers to dextran (100 kDa) to produce a novel dual-drug conjugate dextran-DHA-DTX. The single-drug conjugates dextran-DHA and dextran-DTX were also prepared for comparison. Fluorescent dye Cy7.5-based conjugates dextran-Cy7.5 and dextran-DHA-Cy7.5 were synthesized for cellular uptake study. The dual-drug conjugate dextran-DHA-DTX self-assembled into nanoparticles with the diameter of 102.3 ± 8.3 nm and demonstrated enhanced water solubility and improved pharmacokinetic profiles. Cellular uptake results showed that the dual-drug conjugate entered cells more than the parent DTX by determining the intracellular DTX contents via HPLC/MS analysis and by determining the fluorescent intensity of dextran-Cy7.5 and dextran-DHA-Cy7.5. Importantly, the dual-drug conjugate dextran-DHA-DTX significantly accumulated in tumor tissues and dramatically reduced the DTX concentrations in normal tissues. The dual-drug conjugate completely eradicated all the MCF-7 xenograft tumors without obvious side effects and showed more superior antitumor activity than parent DTX and single-drug conjugate dextran-DTX and dextran-DHA. Both in vitro and in vivo studies showed that DHA enhanced the antitumor activity of dextran-DTX. The polysaccharide dextran-based dual-drug conjugates may represent an effective way to improve the chemotherapeutic agents.

A Novel Dextran-Based Dual Drug Conjugate Targeted Tumors with High Biodistribution Ratio of Tumors to Normal Tissues.

Purpose: Most chemotherapeutic agents possess poor water solubility and show more significant accumulations in normal tissues than in tumor tissues, resulting in serious side effects. To this end, a novel dextran-based dual drug delivery system with high biodistribution ratio of tumors to normal tissues was developed. Methods: A bi-functionalized dextran was developed, and several negatively charged dextran-based dual conjugates containing two different types of drugs, docetaxel and docosahexaenoic acid (DTX and DHA, respectively) were synthesized. The structures of these conjugates were characterized using nuclear magnetic resonance and liquid chromatography/mass spectrometry (1H-NMR and LC/MS, respectively) analysis. Cell growth inhibition, apoptosis, cell cycle distribution, and cellular uptake were measured in vitro. Drug biodistribution and pharmacokinetics were investigated in mice bearing 4T1 tumors using LC/MS analysis. Drug biodistribution was also explored by in vivo imaging. The effects of these conjugates on tumor growth were evaluated in three mice models. Results: The dextran-docosahexaenoic acid (DHA)- docetaxel (DTX) conjugates caused a significant enhancement of DTX water solubility and improvement in pharmacokinetic characteristics. The optimized dextran-DHA-DTX conjugate A treatment produced a 2.1- to 15.5-fold increase in intra-tumoral DTX amounts for up to 96 h compared to parent DTX treatment. Meanwhile, the concentrations of DTX released from conjugate A in normal tissues were much lower than those of the parent DTX. This study demonstrated that DHA could lead to an improvement in the efficacy of the conjugates and that the conjugate with the shortest linker displayed more activity than conjugates with longer linkers. Moreover, conjugate A completely eradicated all MCF-7 xenograft tumors without causing any obvious side effects and totally outperformed both the conventional DTX formulation and Abraxane in mice. Conclusion: These dextran-based dual drug conjugates may represent an innovative tumor targeting drug delivery system that can selectively deliver anticancer agents to tumors.

Complete regression of xenografted breast tumors by dextran-based dual drug conjugates containing paclitaxel and docosahexaenoic acid.

In this study, a novel carboxymethyl dextran (CMD)-based dual drug delivery system that delivering two water insoluble drugs to tumor sites was developed and evaluated for anticancer activities. Paclitaxel (PTX) and docosahexaenoic acid (DHA) were covalently coupled with CMD to generate CMD-DHA-PTX conjugate S and conjugate L with different linkers containing amino acids Gly-Gly or Lys-Gly-Gly, respectively. Both conjugates possessed high PTX loading contents and enhanced water solubility, as well as the ability of being self-assembled into nanoparticles with the nanoparticle size ranged from 88.7 nm to 94.7 nm. These two conjugates released free PTX continuously in plasma and cancer cells. The conjugate S exhibited improved pharmacokinetic parameters and higher distribution extent in tumor sites than the parent PTX, Abraxane and the conjugate L. The antitumor efficacy of these two conjugates outperformed parent PTX formulation and Abraxane in nude mice bearing breast cancer cells MCF-7. More importantly, the conjugate S treatment eliminated all the xenograft tumors without causing any mice body weight loss in mice model. This study revealed that the dextran-based dual drug conjugates may represent an effective and innovative way to deliver anticancer agents to a variety of tumors.

The enhanced antitumor activity of the polymeric conjugate covalently coupled with docetaxel and docosahexaenoic acid.

Docetaxel (DTX) has been widely used for the treatment of many types of cancer. However, DTX is poorly water-soluble and commercial DTX is formulated in non-ionic surfactant polysorbate 80 and ethanol, thereby leading to hypersensitivity and serious side effects. Herein, a polymer dual drug conjugate was synthesized by coupling DTX and docosahexaenoic acid (DHA) with bifunctionalized dextran. The polysaccharide conjugate dextran-DHA-DTX possessed high water solubility and was self-assembled into nanoparticles with a diameter of 98.0 ± 6.4 nm. Pharmacokinetic and biodistribution studies showed that the dextran-DHA-DTX dual drug conjugate not only had significantly prolonged blood circulation but was also selectively accumulated in the tumor with reduced drug distribution in normal tissues. The conjugate exhibited a superior therapeutic effect in both xenograft nude mice models without causing any systemic side effects. Notably, the conjugate nearly eliminated all xenograft tumors in nude mice bearing breast cancer cells MCF-7. This study revealed that the dextran-based dual drug delivery system may provide an effective strategy to selectively deliver DTX to tumor sites.