Study of siRNA Delivery via Polymeric Nanoparticles in Combination with Angiogenesis Inhibitor for The Treatment of AFP-Related Liver Cancer.

Angiogenesis inhibitor drugs have been explored as important pharmacological agents for cancer therapy, including hepatocellular carcinoma. These agents have several drawbacks, such as drug resistance, nonspecific toxicity, and systemic side effects. Therefore, combination therapy of the drug and small interfering RNA could be a promising option to achieve high therapeutic efficacy while allowing a lower systemic dose. Therefore, we studied adding an alpha-fetoprotein siRNA (AFP-siRNA) incorporated on polymeric nanoparticles (NPs) along with angiogenesis inhibitor drugs. The AFP siRNA-loaded NPs were successfully synthesized at an average size of 242.00 ± 2.54 nm. Combination treatment of AFP-siRNA NPs and a low dose of sunitinib produced a synergistic effect in decreasing cell viability in an in vitro hepatocellular carcinoma (HCC) model. AFP-siRNA NPs together with sorafenib or sunitinib greatly inhibited cell proliferation, showing only 39.29 ± 2.72 and 44.04 ± 3.05% cell viability, respectively. Moreover, quantitative reverse transcription PCR (qRT-PCR) demonstrated that AFP-siRNA incorporated with NPs could significantly silence AFP-mRNA expression compared to unloaded NPs. Interestingly, the expression level of AFP-mRNA was further decreased to 28.53 ± 5.10% when sunitinib was added. Therefore, this finding was considered a new promising candidate for HCC treatment in reducing cell proliferation and enhancing therapeutic outcomes.

PLGA nanoparticles containing α-fetoprotein siRNA induce apoptosis and enhance the cytotoxic effects of doxorubicin in human liver cancer cell line.

Hepatocellular carcinoma (HCC) is one of the most common cancers and is a leading cause of death. Delivery of therapeutic molecules, e.g., siRNA, to HCC cells could potentially be an alternative treatment for HCC. In this study, the siRNA targeting α-fetoprotein (AFP) mRNA was found to specifically induce apoptosis and significant cell death in HepG2 cells. It also enhanced the cytotoxic effects of doxorubicin by about two-fold, making it the candidate therapeutic molecule for HCC treatment. To deliver the siRNAs into HCC cells, the AFP siRNAs were loaded into the nanoparticles based on poly (lactic-co-glycolic) acid (PLGA). These nanoparticles induced apoptosis in HepG2 cells and synergistically increased the cytotoxicity of doxorubicin. In summary, the delivery of the AFP siRNA-loaded PLGA nanoparticles in combination with doxorubicin could be a very promising approach for the treatment of HCC.

Nanoparticle facilitated inhalational delivery of erythropoietin receptor cDNA protects against hyperoxic lung injury.

Our goals were to develop and establish nanoparticle (NP)-facilitated inhalational gene delivery, and to validate its biomedical application by testing the hypothesis that targeted upregulation of pulmonary erythropoietin receptor (EpoR) expression protects against lung injury. Poly-lactic-co-glycolic acid (PLGA) NPs encapsulating various tracers were characterized and nebulizated into rat lungs. Widespread NP uptake and distribution within alveolar cells were visualized by magnetic resonance imaging, and fluorescent and electron microscopy. Inhalation of nebulized NPs bearing EpoR cDNA upregulated pulmonary EpoR expression and downstream signal transduction (ERK1/2 and STAT5 phosphorylation) in rats for up to 21 days, and attenuated hyperoxia-induced damage in lung tissue based on apoptosis, oxidative damage of DNA, protein and lipid, tissue edema, and alveolar morphology compared to vector-treated control animals. These results establish the feasibility and therapeutic efficacy of NP-facilitated cDNA delivery to the lung, and demonstrate that targeted pulmonary EpoR upregulation mitigates acute oxidative lung damage. FROM THE CLINICAL EDITOR: Acute lung injury often results in significant morbidity and mortality, and current therapeutic modalities have proven to be ineffective. In this article, the authors developed nanocarrier based gene therapy in an attempt to upregulate the expression of pulmonary erythropoietin receptor in an animal model. Inhalation delivery resulted in reduction of lung damage.

Molecularly Imprinted Polymer-Amyloid Fibril-Based Electrochemical Biosensor for Ultrasensitive Detection of Tryptophan.

A tryptophan (Trp) sensor was investigated based on electrochemical impedance spectroscopy (EIS) of a molecularly imprinted polymer on a lysozyme amyloid fibril (MIP-AF). The MIP-AF was composed of aniline as a monomer chemically polymerized in the presence of a Trp template molecule onto the AF surface. After extracting the template molecule, the MIP-AF had cavities with a high affinity for the Trp molecules. The obtained MIP-AF demonstrated rapid Trp adsorption and substantial binding capacity (50 µM mg-1). Trp determination was studied using non-Faradaic EIS by drop drying the MIP-AF on the working electrode of a screen-printed electrode. The MIP-AF provided a large linear range (10 pM-80 µM), a low detection limit (8 pM), and high selectivity for Trp determination. Furthermore, the proposed method also indicates that the MIP-AF can be used to determine Trp in real samples such as milk and cancer cell media.

Electrospun biodegradable elastic polyurethane scaffolds with dipyridamole release for small diameter vascular grafts.

Acellular biodegradable small diameter vascular grafts (SDVGs) require antithrombosis, intimal hyperplasia inhibition and rapid endothelialization to improve the graft patency. However, current antithrombosis and antiproliferation approaches often conflict with endothelial cell layer formation on SDVGs. To address this limitation, biodegradable elastic polyurethane urea (BPU) and the drug dipyridamole (DPA) were mixed and then electrospun into a biodegradable fibrous scaffold. The BPU would provide the appropriate mechanical support, while the DPA in the scaffold would offer biofunctions as required above. We found that the resulting scaffolds had tensile strengths and strains comparable with human coronary artery. The DPA in the scaffolds was continuously released up to 91 days in phosphate buffer solution at 37 °C, with a low burst release within the first 3 days. Compared to BPU alone, improved non-thrombogenicity of the DPA-loaded BPU scaffolds was evidenced with extended human blood clotting time, lower TAT complex concentration, lower hemolysis and reduced human platelet deposition. The scaffolds with a higher DPA content (5 and 10%) inhibited proliferation of human aortic smooth muscle cell significantly. Furthermore, the DPA-loaded scaffolds had no adverse effect on human aortic endothelial cell growth, yet it improved their proliferation. The attractive mechanical properties and biofunctions of the DPA-loaded BPU scaffold indicate its potential as an acellular biodegradable SDVG for vascular replacement.

Dual growth factor releasing multi-functional nanofibers for wound healing.

The objective of this research is to develop a dual growth factor-releasing nanoparticle-in-nanofiber system for wound healing applications. In order to mimic and promote the natural healing procedure, chitosan and poly(ethylene oxide) were electrospun into nanofibrous meshes as mimics of extracellular matrix. Vascular endothelial growth factor (VEGF) was loaded within nanofibers to promote angiogenesis in the short term. In addition, platelet-derived growth factor-BB (PDGF-BB) encapsulated poly(lactic-co-glycolic acid) nanoparticles were embedded inside nanofibers to generate a sustained release of PDGF-BB for accelerated tissue regeneration and remodeling. In vitro studies revealed that our nanofibrous composites delivered VEGF quickly and PDGF-BB in a relayed manner, supported fibroblast growth and exhibited anti-bacterial activities. A preliminary in vivo study performed on normal full thickness rat skin wound models demonstrated that nanofiber/nanoparticle scaffolds significantly accelerated the wound healing process by promoting angiogenesis, increasing re-epithelialization and controlling granulation tissue formation. For later stages of healing, evidence also showed quicker collagen deposition and earlier remodeling of the injured site to achieve a faster full regeneration of skin compared to the commercial Hydrofera Blue® wound dressing. These results suggest that our nanoparticle-in-nanofiber system could provide a promising treatment for normal and chronic wound healing.