Cytotoxicity of thermo-responsive polymeric nanoparticles based on N-isopropylacrylamide for potential application as a bioscaffold.

Polymeric nanoparticles based on poly-N-isopropylacrylamide (pNiPAM NPs) and their bio-medical applications have been widely investigated in recent years. These tunable nanoparticles are considered to be great candidates for drug delivery systems, biosensors and bioanalytical devices. Thus, the biocompatibility and toxicity of these nanoparticles is clearly a crucial issue. In this work, the cytotoxicity of thermo-responsive pNiPAM nanoparticles was studied, followed by a detailed analysis of the NPs morphology in growing cell cultures and their 3D structure. Cytotoxic examination was conducted for two cell cultures - HeLa (cervical cancer cell line) and HeK293 (human embryonic kidney cell line), employing MTT (3-4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide) assay and viability tests. We used Cryo-SEM (scanning electron microscopy) and fluorescence microscopy (IN Cell Analyzer) in order to investigate the morphological structure of the polymer network. We show that pNiPAM nanoparticles do not exhibit any cytotoxicity effects on the investigated cell lines. Additionally, we report that the pNiPAM nanoparticle based scaffold promotes cell growth.

Synthesis and in vitro and in vivo evaluations of poly(ethylene glycol)-block-poly(4-vinylbenzylphosphonate) magnetic nanoparticles containing doxorubicin as a potential targeted drug delivery system.

The main challenge in antitumor chemotherapy is to enhance the curative effect and minimize the adverse effects of an anticancer drug. Administration of functionalized magnetic iron oxide nanoparticles is one of the strategies to improve sensitivity to cancer chemotherapy, and these nanoparticles are attractive materials that have been widely used in medicine for various applications, including diagnostic imaging and therapeutic applications. In this study, we describe the synthesis and characterization of drug-loaded iron oxide nanoparticles. Our aim was to obtain a biocompatible and injectable nanocarrier with anticancer activity. Iron oxide nanoparticles (IONs) were synthesized by alkali co-precipitation of iron salts followed by coating with our original surface modification agent, poly(ethylene glycol)-block-poly(4-vinylbenzylphosphonate) copolymer (PEG-PIONs). An anticancer drug doxorubicin (DOX), which clinical use is associated with cardiotoxicity, was loaded onto PEG-PIONs (PEG-PIONs/DOX), and to the best of our knowledge, this formulation showed higher drug encapsulation efficiency (drug loading capacity of the nanocarrier was 11.7%) than other formulations previously reported. PEG-PIONs/DOX had a hydrodynamic diameter of about 35nm and were stable in biological conditions over a period more than one month and showed stable and continuous in vitro drug release and antiproliferative effects on cancer cells. Fluorescent imaging indicated internalization of the PEG-PIONs/DOX in the cytoplasm of cancer cells. Biodistribution studies showed that PEG-PIONs/DOX preferentially accumulate in the tumor region via enhanced permeability and retention effect. In addition, analysis of the serum levels of enzymes indicated that PEG-PIONs/DOX reduced the cardiotoxicity associated with free DOX. These results indicate that PEG-PIONs/DOX have the potential for targeted delivery of antitumor drugs via systemic administration.