Reduction-sensitive mixed micelles based on mPEG-SS-PzLL /TPGS to enhance anticancer efficiency of doxorubicin

Polymeric Micellar Systems-A Special Emphasis on "Smart" Drug Delivery

Concurrent developments in anticancer nanotechnological treatments have been observed as the burden of cancer increases every year. The 21st century has seen a transformation in the study of medicine thanks to the advancement in the field of material science and nanomedicine. Improved drug delivery systems with proven efficacy and fewer side effects have been made possible. Nanoformulations with varied functions are being created using lipids, polymers, and inorganic and peptide-based nanomedicines. Therefore, thorough knowledge of these intelligent nanomedicines is crucial for developing very promising drug delivery systems. Polymeric micelles are often simple to make and have high solubilization characteristics; as a result, they seem to be a promising alternative to other nanosystems. Even though recent studies have provided an overview of polymeric micelles, here we included a discussion on the "intelligent" drug delivery from these systems. We also summarized the state-of-the-art and the most recent developments of polymeric micellar systems with respect to cancer treatments. Additionally, we gave significant attention to the clinical translation potential of polymeric micellar systems in the treatment of various cancers.

Conjugation of folic acid with poly (NVCL-co-PEGMA)-grafted chitosan as a new doxorubicin delivery system

This paper aimed to investigate the synthesis of a novel drug delivery system (DDS) to target tumors and implement the controlled release of doxorubicin (DOX). Chitosan was modified with 3-mercaptopropyltrimethoxysilane and subjected to graft polymerization to implement grafting with the biocompatible thermosensitive copolymer of poly (NVCL-co-PEGMA). A folate receptor-targeting agent was obtained by attaching folic acid. The DDS loading capacity for DOX via physisorption was obtained to be 846.45 mg/g. The synthesized DDS showed temperature- and pH-sensitive drug release behavior in vitro. A temperature of 37 °C and a pH of 7.4 hindered the DOX release, whereas a temperature of 40 °C and a pH of 5.5 led to DOX release acceleration. In addition, the release of DOX was found to occur in a Fickian diffusion mechanism. The MTT assay tests indicated that the synthesized DDS was not detectably toxic to cell lines of breast cancer, while the toxicity of the DOX-loaded DDS was found to be substantial. The cell absorption enhancement of folic acid led to higher cytotoxicity of the DOX-loaded DDS than bare DOX. As a result, the proposed DDS could be a promising alternative for the targeted therapy of breast cancer through controlled drug release.

A Redox-Activatable and Targeted Photosensitizing Agent to Deliver Doxorubicin for Combining Chemotherapy and Photodynamic Therapy

Currently, tumors have become a serious disease threatening human health and life in modern society. Photo-chemo combination therapy is considered to be an important method to improving the efficiency of tumor treatment, especially in the treatment of multi-drug-resistant tumors. However, the application of photo-chemo combination therapy has been limited by the poor water solubility of photosensitizers, low tumor targeting, and high side effects of chemotherapy drugs. In order to solve these problems, a smart nano drug delivery platform FA-PEG-ss-PLL(-g-Ce6) designed and synthesized by us. The smart nano drug carrier uses folic acid (FA) as the targeting group, polyethylene glycol (PEG) as the hydrophilic end, Ce6-grafted polylysine (PLL(-g-Ce6)) as the hydrophobic end, and Chlorin e6 (Ce6) as the photosensitizer of photodynamic therapy, and it connects PEG to PLL by a redox-responsive cleavable disulfide linker (-ss-). Finally, the combination of tumor chemotherapy and photodynamic therapy (PDT) is realized by loading with anticancer drug doxorubicin (DOX) to the intelligent carrier. In vitro experiments showed that the drug loading content (DLC%) of DOX@FA-PEG-ss-PLL(-g-Ce6) nanoparticles (DOX@FPLC NPs) was as high as 14.83%, and the nanoparticles had good serum stability, reduction sensitivity and hemocompatibility. From the cytotoxicity assays in vitro, we found that under 664 nm laser irradiation DOX@FPLC NPs showed stronger toxicity to MCF-7 cells than did DOX, Ce6 + laser, and DOX + Ce6 + laser. Moreover, the antitumor efficiency in vivo and histopathological analysis showed that DOX@FPLC NPs under 664 nm laser irradiation exhibited higher antitumor activity and lower systemic toxicity than single chemotherapy. These results suggested that the FA-PEG-ss-PLL(-g-Ce6) nano drug delivery platform has considerable potential for the combination of chemotherapy and PDT.