Investigation of the Therapeutic Effects of Palbociclib Conjugated Magnetic Nanoparticles on Different Types of Breast Cancer Cell Lines.

Introduction: Drug targeting and controlled drug release systems in cancer treatment have many advantages over conventional chemotherapy in terms of limiting systemic toxicity, side effects, and overcoming drug resistance. Methods and Results: In this paper, fabricating nanoscale delivery system composed of magnetic nanoparticles (MNPs) covered with poly-amidoamine (PAMAM) dendrimers and using its advantages were fully used to help the chemotherapeutic drug, Palbociclib, effectively reach tumors, specifically and stay stable in the circulation longer. In order to determine whether conjugate selectivity can be increased for the specific drug type, we have reported different strategies for loading and conjugation of Palbociclib to different generations of magnetic PAMAM dendrimers. The best method leading to the highest amount of Palbociclib conjugation was chosen, and the characterization of the Palbociclib conjugated dendrimeric magnetic nanoparticles (PAL-DcMNPs) were performed. In vitro pharmacological activity of the conjugation was demonstrated by measuring the cell viability and lactate dehydrogenase (LHD) release. Obtained results indicated that PAL-DcMNPs treatment of the breast cancer cell lines, leads to an increase in cell toxicity compared to free Palbociclib. The observed effects were more evident for MCF-7 cells than for MDA-MB231 and SKBR3 cells, considering that viability decreased to 30% at 2.5 µM treatment of PAL-DcMNPs at MCF-7 cells. Finally, in Palbociclib and PAL-DcMNPs treated breast cancer cells, the expression levels of some pro-apoptotic and drug resistance related genes were performed by RT-PCR analysis. Conclusion: Our knowledge indicates that the proposed approach is novel, and it can provide new insight into the development of Palbociclib targeting delivery system for cancer treatment.

Development of a microfluidic platform to maintain viability of micro-dissected tumor slices in culture.

One of the issues limiting the development of personalized medicine is the absence of realistic models that reflect the nature and complexity of tumor tissues. We described a new tissue culture approach that combines a microfluidic chip with the microdissected breast cancer tumor. "Tumor-on-a-chip" devices are suitable for precision medicine since the viability of tissue samples is maintained during the culture period by continuously feeding fresh media and eliminating metabolic wastes from the tissue. However, the mass transport of oxygen, which arguably is the most critical nutrient, is rarely assessed. According to our results, transportation of oxygen provides satisfactory in vivo oxygenation within the system. A high level of dissolved oxygen, around 98%-100% for every 24 h, was measurable in the outlet medium. The microfluidic chip system developed within the scope of this study allows living and testing tumor tissues under laboratory conditions. In this study, tumors were generated in CD-1 mice using MDA-MB-231 and SKBR-3 cell lines. Microdissected tumor tissues were cultured both in the newly developed microfluidic chip system and in conventional 24-well culture plates. Two systems were compared for two different types of tumors. The confocal microscopy analyses, lactate dehydrogenase release, and glucose consumption values showed that the tissues in the microfluidic system remained more viable with respect to the conventional well plate culturing method, up to 96 h. The new culturing technique described here may be superior to conventional culturing techniques for developing new treatment strategies, such as testing chemotherapeutics on tumor samples from individual patients.

Characterization of Gemcitabine Loaded Polyhydroxybutyrate Coated Magnetic Nanoparticles for Targeted Drug Delivery.

BACKGROUND: Targeted drug delivery is one of the recent hot topics in cancer therapy. Because of having a targeting potential under the magnetic field and a suitable surface for the attachment of different therapeutic moieties, magnetic nanoparticles are widely studied for their applications in medicine. OBJECTIVE: Gemcitabine loaded polyhydroxybutyrate coated magnetic nanoparticles (Gem-PHB-MNPs) were synthesized and characterized for the treatment of breast cancer by the targeted drug delivery method. METHODS: The characterization of nanoparticles was confirmed by FTIR, XPS, TEM, and spectrophotometric analyses. The cytotoxicities of drug-free nanoparticles and Gemcitabine loaded nanoparticles were determined with cell proliferation assay using SKBR-3 and MCF-7 breast cancer cell lines. RESULTS: The release of Gemcitabine from PHB-MNPs indicated a pH-dependent pattern, which is a desirable release characteristic, since the pH of the tumor microenvironment and endosomal structures are acidic, while bloodstream and healthy-tissues are neutral. Drug-free PHB-MNPs were not cytotoxic to the SKBR-3 and MCF- 7 cells, whereas the Gemcitabine loaded PHB-MNPs was about two-fold as cytotoxic with respect to free Gemcitabine. In vitro targeting ability of PHB-MNPs was shown under the magnetic field. CONCLUSION: Considering these facts, we may suggest that these nanoparticles can be a promising candidate for the development of a novel targeted drug delivery system for breast cancer.

Half generations magnetic PAMAM dendrimers as an effective system for targeted gemcitabine delivery.

Tumor-specific delivery of anticancer drugs by magnetic nanoparticles will maximize the efficacy of the drug and minimize side effects, and reduce systemic toxicity. The magnetic core of these nanoparticles provides an advantage for selective drug targeting as they can be targeted to the tumor site and accumulated in cancer cells by means of an external magnetic field. Magnetic nanoparticles can be coated with Polyamidoamine (PAMAM) dendrimer and loaded with drugs. However, biomedical applications of PAMAM dendrimers are limited due to their toxicity associated with their multiple cationic charges due to terminal NH2 groups. Modifying the positively charged end groups with negatively charged COOH groups, is a satisfactory strategy for obtaining less toxic PAMAM dendrimers. Gemcitabine being an analogue of deoxycytidine, is an effective anticancer drug. However, clinical benefits of Gemcitabine are limited due to its short biological half-life. The aim of this study was to obtain an effective, less toxic targeted delivery system for Gemcitabine. Half generations, between G4.5 and G7.5, of PAMAM dendrimer coated magnetic nanoparticles (DcMNPs) were synthesized and conjugated with Gemcitabine. TEM images showed nanoscale size (12-14nm) of the nanoparticles. The zeta-potential analysis indicated a decreased negativity of surface charge in drug bound dendrimer compared to the empty nanoparticles. Gemcitabine was effectively conjugated successfully onto the surface of half-generations of PAMAM DcMNPs. It was observed Gemcitabine did not effectively bind to Generations G4 and G5. The highest drug loading was obtained for DcMNPs with Generation 5.5. Empty nanoparticles showed no significant cytotoxicity on SKBR-3 and MCF-7 cells. On the other hand, Gemcitabine loaded nanoparticles were 6.0 fold more toxic on SKBR-3 and 3.0 fold more toxic on MCF-7 cells compared to free Gemcitabine. Gemcitabine loaded on Generation 5.5 DcMNPs showed a higher stability than free Gemcitabine. About 94% of the drug was retained over 6 weeks period, at pH 7.2. Due to their targetability under magnetic field, stability, size distribution, cellular uptake and toxicity characteristics the dendrimeric nanoparticles obtained in this study can be useful a delivery system for Gemcitabine in cancer therapy.

Loading of Gemcitabine on chitosan magnetic nanoparticles increases the anti-cancer efficacy of the drug.

Targeted delivery of anti-cancer drugs increase the efficacy, while decreasing adverse effects. Among various delivery systems, chitosan coated iron oxide nanoparticles (CsMNPs) gained attention with their biocompatibility, biodegradability, low toxicity and targetability under magnetic field. This study aimed to increase the cellular uptake and efficacy of Gemcitabine. CsMNPs were synthesized by in situ co-precipitation and Gemcitabine was loaded onto the nanoparticles. Nanoparticle characterization was performed by TEM, FTIR, XPS, and zeta potential. Gemcitabine release and stability was analyzed. The cellular uptake was shown. Cytotoxicity of free-Gemcitabine and Gem-CsMNPs were examined on SKBR and MCF-7 breast cancer cells by XTT assay. Gemcitabine loading was optimized as 30µM by spectrophotometric analyses. Drug release was highest (65%) at pH 4.2, while it was 8% at pH 7.2. This is a desired release characteristic since pH of tumor-tissue and endosomes are acidic, while the blood-stream and healthy-tissues are neutral. Peaks reflecting the presence of Gemcitabine were observed in FTIR and XPS. At neutral pH, zeta potential increased after Gemcitabine loading. TEM images displayed, Gem-CsMNPs were 4nm with uniform size-distribution and have spherical shape. The cellular uptake and targetability of CsMNPs was studied on MCF-7 breast cancer cell lines. IC50 value of Gem-CsMNPs was 1.4 fold and 2.6 fold lower than free-Gem on SKBR-3 and MCF-7 cell lines respectively, indicating the increased efficacy of Gemcitabine when loaded onto nanoparticles. Targetability by magnetic field, stability, size distribution, cellular uptake and toxicity characteristics of CsMNPs in this study provides a useful targeted delivery system for Gemcitabine in cancer therapy.

Effect of gemcitabine and retinoic acid loaded PAMAM dendrimer-coated magnetic nanoparticles on pancreatic cancer and stellate cell lines.

Gemcitabine is an anticancer drug used in the treatment of different cancer types, including pancreatic ductal adenocarcinoma. The maximum tolerated dose in humans is restricted by its side effects on healty cells. Furthermore, the fibrotic stroma produced by the pancreatic stellate cells prevents effective delivery of chemotherapeutic agents providing a safe-haven for the cancer cells. This becomes more of a problem considering the short half-life of this drug. Magnetic nanoparticle-based targeted drug delivery systems are a promising alternative to overcome the limitations of classical chemotherapies. The aim of this study is to obtain an effective targeted delivery system for gemcitabine using magnetic nanoparticles (MNPs) and all-trans retinoic acid (ATRA). This dual approach targets the tumor cells and its infrastructure - stellate cells - simultaneously. Gemcitabine and ATRA were loaded onto the PAMAM dendrimer-coated magnetic nanoparticles (DcMNPs), which were synthesized and characterized previously. Drug loading and release characteristics, and stability of the nanoparticles were investigated. Gemcitabine and ATRA loaded MNPs are efficiently taken up by pancreatic cancer and stellate cells successfully targeting and eliminating both cells. Results of this study can provide new insights on pancreatic cancer therapy where tumor is seen as a system with its stroma insead of epithelial cells alone.