Intracellular Delivery of Micron-Sized Magnetic Particles through a Virus Infection Pathway.

Micron-sized magnetic particles (M-MPs) have low toxicity, strong magnetic signals, and long-term retention capability, which are significant advantages for their application in biomedical imaging. Unfortunately, M-MPs are only internalized by few cell types, such as macrophages and phagocytes, and because of this lack of active intracellular delivery, their applications are restricted. The emergence of self-assembled virus-like particles (VLPs) offers a viable approach to drive M-MPs into cells, although the specific mechanism has not been revealed. In this study, we investigated in detail the intracellular pathway of M-MPs mediated by VLPs using a fluorescence co-localization method. The results indicated that the intracellular movement of M-MPs was consistent with the virus infection pathway, specifically caveolae-dependent endocytosis, transportation through microtubules, and accumulation in the endoplasmic reticulum. This study provides experimental support for the active transport of M-MPs into other cell types, thereby further extending their applications.

Rhomboidal Pt(II) Metallacycle-Based Hybrid Viral Nanoparticles for Cell Imaging.

Supramolecular coordination complexes (SCCs) have emerged as anticancer agents. Tracking the movement of these metallic anticancer agents plays an important role in the field of biomedicines. Herein, we describe a method for tracking the movement of a rhomboidal Pt(II) metallacycle agent using the quantum dots encapsidation in vitro self-assembly system of viral proteins. When incubated with living Vero cells, self-assembly of hybrid viral nanoparticles were employed for simultaneous cell imaging and visual transmission of the Pt(II) metallacycle agent. Considering these results, we believe that the multifunctional biomaterials consisting of a supramolecular coordination complex and quantum dots provide a new alternative for probing of the delivery of Pt(II) metallacycle drugs.

Cell Type-Dependent Specificity and Anti-Inflammatory Effects of Charge-Reversible MSNs-COS-CMC for Targeted Drug Delivery in Cervical Carcinoma.

The surface charge of nanocarriers inevitably affects drug delivery efficiency; however, the cancer cell specificity, anti-inflammatory effects, and charge-reversal points remain to be further addressed in biomedical applications. The aim of this study was to comprehensively assess the cancer cell specificity of DOX-loaded mesoporous silica-chitosan oligosaccharide-carboxymethyl chitosan nanoparticles (DOX@MSNs-COS-CMC) in MCF-7 and HeLa cells, inhibit the production of inflammatory cytokines, and improve the drug accumulation in the tumor site. Intracellular results reveal that the retention time prolonged to 48 h in both HeLa and MCF-7 cells at pH 7.4. However, DOX@MSNs-COS-CMC exhibited a cell type-dependent cytotoxicity and enhanced intracellular uptake in HeLa cells at pH 6.5, due to the clathrin-mediated endocytosis and macropinocytosis in HeLa cells in comparison with the vesicular transport in MCF-7 cells. Moreover, Pearson's correlation coefficient value significantly decreased to 0.25 after 8 h, prompting endosomal escape and drug delivery into the HeLa nucleus. After the treatment of MSNs-COS-CMC at 200 µg/mL, the inflammatory cytokines IL-6 and TNF-α level decreased by 70% and 80%, respectively. Tumor inhibition of DOX@MSNs-COS-CMC was 0.4 times higher than free DOX, alleviating cardiotoxicity and inflammation in the HeLa xenograft tumor model. Charge-reversible DOX@MSNs-COS-CMC could be a possible candidate for clinical therapy of cervical carcinoma.

Biocompatible chiral monolithic stationary phase synthesized via atom transfer radical polymerization for high performance liquid chromatographic analysis.

Novel biocompatible chiral monolithic stationary phase was prepared by reverse and direct atom transfer radical polymerization (ATRP) methods. By taking advantages of the controlled/living property of ATRP method, the chiral monolith was prepared by reverse ATRP (RATRP) firstly. An attractive feature of RATRP is the prepared polymer containing a terminal radically transferable atom that can initiate another post-polymerization reaction by direct ATRP. Then, the biocompatible poly(hydroxyethyl methacrylate) (PHEMA) was grafted on the surface of the chiral monolith by direct ATRP as a diffusion barrier for proteins. This biocompatible chiral monolith was successfully used as restricted access stationary phase for determination of enantiomers in biological samples with direct injection by high-performance liquid chromatography (HPLC).