Tumor targeted combination therapeutic system for the effective treatment of drug resistant triple negative breast cancer

Breast cancer has become the malignant tumor with the largest incidence, especially the drug resistant triple negative breast cancer (TNBC). The combination therapeutic system can play a better role in resisting drug resistant TNBC. In this study, dopamine and tumor targeted folic acid modified dopamine were synthesized as carrier materials to construct melanin-like tumor targeted combination therapeutic system. The optimized nanoparticles of CPT/Fe@PDA-FA10 with efficient loading of camptothecin and iron was achieved, which showed tumor targeted delivery ability, pH sensitive controlled release, effective photothermal conversion performance and excellent anti-tumor efficacy in vitro and in vivo. CPT/Fe@PDA-FA10 plus laser could significantly kill the drug resistant tumor cells, inhibit the growth of the orthotopic drug resistant triple negative breast cancer through apoptosis/ferroptosis/photothermal treatment, and had no significant side effects on the main tissues and organs. This strategy provided a new idea for the construction and clinical application of triple-combination therapeutic system as effective treatment for drug resistant triple negative breast cancer.

Pollen-like silica nanoparticles as a nanocarrier for tumor targeted and pH-responsive drug delivery

Aptamer modified hollow silica nanoparticles with pollen structure (plSP@aptamer) were synthesized and used as a nanocarrier for tumor targeted and pH-responsive drug delivery. The 292 ± 14 nm interior void in diameter together with 11.8 nm surface pore size of plSP@aptamer nanoparticles contributed to a high drug loading efficiency of 0.509 g g^-1. Furthermore, the drug delivery system was pH-responsive, and the releasing efficiency was up to 87.5% at pH of 5. The special spikes of this plSP@aptamer nanoparticles acted as "entry claws" to enhanced the interaction between cell and drug nanocarriers and then increased the internalization rate of drug vehicles. The cell uptake assay suggested that most of doxorubicin (DOX)@plSP@aptamer nanoparticles can escape form lysosome and located in nuclei of MCF-7 cells. The targeted performance testing showed that almost no DOX@plSP@aptamer were internalized by normal cells, indicating a high specificity of our drug vehicles. The cytotoxicity of nanoparticles was also investigated, the plSP@aptamer particles had excellent biocompatibility and the cell viability was nearly 100%. After loaded with DOX, DOX@plSP@aptamer showed great potential in targeted therapy of tumors, and only 4.2% MCF-7 cells were viable.

Fluorescent nanoparticles with ultralow chromophore loading for long-term tumor-targeted imaging

Recently, organic dyes with aggregation-induced emission (AIE) have attracted much attention in bioimaging and diagnostics. Relatively, the application of traditional dyes has diminished because of aggregation-caused quenching (ACQ). In this work, we compare the imaging ability of nanoparticle formulations of these two kinds of dyes. Boron dipyrromethene (BODIPY) was chosen as a representative of the ACQ dyes, and an aggregation-induced emission (AIE) dye BPMT was used for comparison. BODIPY and BPMT were entrapped into PEG_5k-PLA_10k to form BODIPY-loaded NPs (BNPs) and BPMT-loaded NPs (ANPs), respectively. In vivo and ex vivo imaging demonstrated that BNP1 with ultralow BODIPY load (0.07%) can effectively accumulate in tumor tissues and enable long-term noninvasive imaging. In contrast, ANP4 with high BPMT load (1.6%) has poor bioimaging ability. In general, our work has certain reference significance for the application of ACQ dyes and AIEgens in bioimaging, diagnostics, and theranostics. STATEMENT OF SIGNIFICANCE: In this work, Boron dipyrromethene (BODIPY) was chosen as a representative of ACQ dyes. As a control, (Z)-2-(4'-(9H-carbazol-9-yl)-[1,1'-biphenyl]-4-yl)-3-(7-(4-(bis(4methoxyphenyl)amino) phenyl) benzo[c] [1,2,5] thiadiazol-4-yl) acrylonitrile (BPMT) was selected as an aggregation-induced emission (AIE) dye. BODIPY and BPMT was entrapped into PEG5k-PLA10k to form BODIPY-loaded NPs (BNPs) and BPMT-loaded NPs (ANPs), respectively. In vivo and ex vivo imaging demonstrated that BNP1 with ultralow BODIPY load (0.07%) can effectively accumulate in tumor tissues and realize long-term noninvasive imaging. The weaknesses of ACQ effect can be converted into advantages by skillful use of nanotechnology, which can not only save the cost but also realize high efficiency targeted cancer imaging.

Construction of redox-responsive tumor targeted cisplatin nano-delivery system for effective cancer chemotherapy

Cisplatin is one of the most widely used platinum-based anticancer chemotherapeutic drugs. However, its low solubility, serious side effects and the development of cisplatin resistance limit its further use in the clinic. Controlling the delivery and release of cisplatin at the targeted site efficiently is a meaningful way to overcome these undesirable side effects of cisplatin. Herein, a tumor targeted and stimuli responsive nano-delivery system for cisplatin was constructed using branched polyethyleneimine (BPEI) as the backbone, disulfide bond as the redox-responsive covalent linker and hyaluronic acid (HA) as targeting recognition unit which can bind selectively to the receptor of CD44, which is highly expressed on the A549 tumor cells. The cisplatin-polyethyleneimine conjugate BPEI-SS-Pt was prepared and the drug loading of cisplatin was up to 32.66 ± 0.06%. After optimized the coating weight ratio of HA and BPEI-SS-Pt, the nanoparticle delivery system HA-(BPEI-SS-Pt)-1/4 outperformed with smaller particle size of 159.0 ± 21.0 nm, narrow polydispersity index (PDI) of 0.069 ± 0.022 and higher cisplatin loading of 29.23 ± 0.18%, showing specific tumor-targeting ability and redox-responsive drug release manner. Moreover, for the treatment of cancer in vivo, it achieved more effective antitumor performance along with minor side effects and systemic toxicity compared with cisplatin which is of great significance for the chemotherapeutic drug in the clinic.

A nanoscale photothermal agent based on a metal-organic coordination polymer as a drug-loading framework for effective combination therapy

Metallic materials are widely emerging as photothermal agents owing to their superior photothermal transduction efficiency and satisfactory photostability. In this study, an iron-based coordination polymer (Fe-CNP) loaded with doxorubicin (DOX) was assessed as a dual-function agent for photothermal therapy (PTT) and tumor-targeted chemotherapy. Fe-CNPs were synthesized by a one-step coordination reaction between Fe³⁺, hydrocaffeic acid, and dopamine-modified hyaluronic acid. A drug-loading method was developed to entrap DOX within Fe-CNPs through the formation of coordination bonds by Fe³⁺ and DOX (Scheme 1). DOX release was rapidly triggered in the cellular acidic environment and further enhanced by hyperpyrexia in the part of tumor, which will kill the remaining tumor cells after PTT. Animal experiments demonstrated complete inhibition of tumor growth without recurrence in 21 days after injection of DOX@Fe-CNPs with NIR laser irradiation. These results confirmed the enhanced anti-tumor efficiency of the chemo-photothermal nanosystem. Our work may reveal a photothermal coordination polymer as a drug-loading framework and highlight the development of metal-organic materials in combined chemo-photothermal therapy. STATEMENT OF SIGNIFICANCE: Photothermal therapy (PTT), which could directly act on tumors, has been considered as a promising treatment method for cancer. The combination of PTT with chemotherapy is attracting tremendous attention because such advanced application can achieve personalized precise medicine. Unfortunately, most PTT materials have photobleaching property, which results in reduced photothermal efficiency. Furthermore, their clinical applications also suffer from low loading capacity of chemotherapeutic drugs or nonbiodegradability in the biological system. In this study, we hypothesized that iron-based coordination polymers (Fe-CNPs) could function dually as agents to deliver both PTT and tumor-targeted chemotherapy by coordination loading of the chemotherapeutic drug doxorubicin (DOX). Our work may open up new avenues to rationally design versatile platforms for photothermal-chemotherapy to obtain synergistically enhanced therapeutic efficacy.

Triple-responsive expansile nanogel for tumor and mitochondria targeted photosensitizer delivery

A pH, thermal, and redox potential triple-responsive expansile nanogel system (TRN), which swells at acidic pH, temperature higher than its transition temperature, and reducing environment, has been developed. TRN quickly expands from 108 nm to over 1200 nm (in diameter), achieving more than 1000-fold size enlargement (in volume), within 2 h in a reducing environment at body temperature. Sigma-2 receptor targeting-ligand functionalized TRN can effectively target head and neck tumor, and help Pc 4 targeting mitochondria inside cancer cells to achieve enhanced photodynamic therapy efficacy.