Design of diffusion-controlled drug delivery devices for controlled release of Paclitaxel

Development and Evaluation of Amlodipine-Polymer Nanocomposites Using Response Surface Methodology

Introduction. Polymer nanoparticles are a key tool to deliver drugs to specific sites and to increase drug bioavailability. Aim. This research aims to use poly amide-disulfide nanoparticles as drug delivery systems. Method. Amlodipine (Amlop) was used as a model, forming Amlop-polymer nanocomposites. In this work, we investigated the effect of independent variables (polymer, Fe3+, Al3+, and pH) on the dependent variables (loading efficiency (%LE), zeta potential, and particle size). Nanocomposites were prepared by an inotropic method. Nanocomposites were characterized by powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), and a release study. Results. From the XRD data, the Amlop-polymer nanocomposite shows semi crystallinity. In addition, the disappearance of drug peaks indicates that the drug was incorporated between the polymer molecules and was amorphous in behavior. The FTIR for the nanocomposite shows the functional group of the drug, which indicates the incorporation of Amlop into the nanocomposite. From FE-SEM, the results showed that our nanocomposites have an average particle size of approximately 130 nm. The release of amlodipine from the Amlop-polymer nanocomposite was found to be controlled, with approximately 85% within approximately 24 hours. Conclusion. The amide-disulfide polymer nanoparticles are promising carriers for different types of drugs.

Chitosan Nanoparticle-Based System: A New Insight into the Promising Controlled Release System for Lung Cancer Treatment

Lung cancer has been recognized as one of the most often diagnosed and perhaps most lethal cancer diseases worldwide. Conventional chemotherapy for lung cancer-related diseases has bumped into various limitations and challenges, including non-targeted drug delivery, short drug retention period, low therapeutic efficacy, and multidrug resistance (MDR). Chitosan (CS), a natural polymer derived from deacetylation of chitin, and comprised of arbitrarily distributed β-(1-4)-linked d-glucosamine (deacetylated unit) and N-acetyl-d-glucosamine (acetylated unit) that exhibits magnificent characteristics, including being mucoadhesive, biodegradable, and biocompatible, has emerged as an essential element for the development of a nano-particulate delivery vehicle. Additionally, the flexibility of CS structure due to the free protonable amino groups in the CS backbone has made it easy for the modification and functionalization of CS to be developed into a nanoparticle system with high adaptability in lung cancer treatment. In this review, the current state of chitosan nanoparticle (CNP) systems, including the advantages, challenges, and opportunities, will be discussed, followed by drug release mechanisms and mathematical kinetic models. Subsequently, various modification routes of CNP for improved and enhanced therapeutic efficacy, as well as other restrictions of conventional drug administration for lung cancer treatment, are covered.

Pharmacodynamic Studies of Fluorescent Diamond Carriers of Doxorubicin in Liver Cancer Cells and Colorectal Cancer Organoids

BACKGROUND

We recently reported on preferential deposition of bare fluorescent diamond particles FDP-NV-700/800nm (FDP-NV) in the liver following intravenous administration to rats. The pharmacokinetics of FDP-NV in that species indicated short residency in the circulation by rapid clearance by the liver. Retention of FDP-NV in the liver was not associated with any pathology. These observations suggested that cancer therapeutics, such as doxorubicin, linked to FDP-NV, could potentially serve for anti-cancer treatment while sparing toxicities of peripheral organs.

PURPOSE

To generate proof-of-concept (POC) and detail mechanisms of action of doxorubicin-coated FDP-NV-700/800nm (FDP-DOX) as a prospective chemotherapeutic for metastatic liver cancer.

METHODS

FDP-DOX was generated by adsorption chemistry. Experimental design included concentration and time-dependent efficacy studies as compared with naïve (baren) FDP-NV in in vitro liver cancer cells models. Uptake of FDP-NV and FDP-DOX by HepG-2, Hep-3B and hCRC organoids were demonstrated by flow-cytometry and fluorescent microscopy. FDP-DOX pharmacodynamic effects included metabolic as well as cell death biomarkers Annexin V, TUNEL and LDH leakage. DOX desorpted from FDP-DOX was assessed by confocal microscopy and chemical assay of cells fractions.

RESULTS

FDP-DOX efficacy was dose- and time-dependent and manifested in both liver cancer cell lines and human CRC organoids. FDP-DOX was rapidly internalized into cancer cells/organoids leading to cancer growth inhibition and apoptosis. FDP-DOX disrupted cell membrane integrity as evident by LDH release and suppressing mitochondrial metabolic pathways (AlamarBlue assay). Access of free DOX to the nuclei was confirmed by direct UV-Visible fluorescent assay and confocal microscopy of DOX fluorescence.

CONCLUSION

The rapid uptake and profound cancer inhibition observed using FDP-DOX in clinically relevant cancer models, highlight FDP-DOX promise for cancer chemotherapeutics. We also conclude that the in vitro data justify further investment in in vivo POC studies.