Self-organized Precipitation Method Research Articles

Particles and film preparation of ester-free type poly(trimethylene carbonate) derivatives bearing aromatic groups initiated with hydrophilic initiators

As our previous reports of facile synthetic ester-free type trimethylene carbonate-aromatic derivatives, we were herein prepared a series of particles and thin films of poly(trimethylene carbonate) (PTMC) bearing diphenyl-, bis-phenyl, and trityl pendants. The hydrophilic groups were featured at chain end while the side chain was introduced several hydrophobic aromatic groups as well as typical ester-free PTMC. Approaching the particle formation, oligo ethylene glycol was selected as hydrophilic initiator due to the high mobility, and biocompatibility. The synthetic PTMC particles were fabricated via self-organized precipitation method, its structural properties, morphologies, and surface behaviors were systematically explored. To examine the impact of structure, we investigated the degradation study of PTMC-trityl film coating which was enabled to convey a deceleration in enzymatic system.

Preparation of Cellulose Nanocrystal Based Core-Shell Particles with Tunable Component Location

Abstract We report a versatile method for preparing a particulate composite based on cellulose nanocrystals (CNCs) and polyethylene glycol (PEG) via a self-organized precipitation method. The particulate composite had a core–shell structure, and depending on the molecular weight of the PEG, two types of particulates could form: one with CNCs as the core and the other with CNCs as the shell.

Spontaneous Formation of Nanoparticles from Peptide-Vinyl Polymer Diblock Hybrids Prepared by RAFT Polymerization and Their Interactions with Cells.

Novel polymeric nanoparticles (NPs) with uniform sizes were prepared from peptide–vinyl polymer diblock hybrids by the self-organized precipitation method. Hybrid polymers of polystyrene (PSt) and tetrapeptide (cell-binding epitope RGDS, reverse SDGR, cationic KKKK, and anionic DDDD) were successfully synthesized by combining solid-phase peptide synthesis and reversible addition fragmentation chain transfer polymerization methods. Narrowly dispersed hybrid polymers (polydispersity index < 1.25, Mn 14 000–17 000) were obtained. Altering the preparation conditions easily tuned the size and size distribution of the NPs. When the ζ-potentials for the NP suspensions were measured at pH 6.0, the obtained values corresponded to the net charge of each peptide segment. More importantly, the NPs could encapsulate fluorescent Nile red (NR) and magnetic iron oxide NP (MNP), which might be suitable for fluorescent imaging and magnet-induced patterning of cells, respectively. The interactions of NPs with cells (NIH/3T3 fibroblast) and the magnetic effects were examined for NR/MNP-loaded PSt–RGDS and −SDGR NPs. Both NPs were readily incorporated into cells, but only NR/MNP-loaded PSt–RGDS NP showed magnetic responsiveness in cell adhesion and cultures.

Multifunctional decoration of alpha-tocopheryl succinate-based NP for cancer treatment: effect of TPP and LTVSPWY peptide.

Active targeting not only of a specific cell but also a specific organelle maximizes the therapeutic activity minimizing adverse side effects in healthy tissues. The present work describes the synthesis, characterization, and in vitro biological activity of active targeting nanoparticles(NP) for cancer therapy based on α-tocopheryl succinate (α-TOS), a well-known mitocan, that selectively induces apoptosis of cancer cells and proliferalting endothelial cells. Human epidermal growth factor receptor 2 (HER2) targeting peptide LTVSPWY (PEP) and triphenylphosphonium lipophilic cation (TPP) were conjugated to a previously optimized RAFT block copolymer that formed self-assembled NP of appropriate size for this application and low polydispersity by self-organized precipitation method. PEP and TPP were included in order to target not only HER2 positive cancer cells, but also the mitochondria of these cancer cells, respectively. The in vitro experiments demonstrated the faster incorporation of the active-targeting NP and the higher accumulation of TPP-bearing NP in the mitochondria of MDA-MB-453 HER2 positive cancer cells compared to non-decorated NP. Moreover, the encapsulation of additional α-TOS in the hydrophobic core of the NP was achieved with high efficiencies. The loaded NP presented higher cytotoxicity than unloaded NP but preserved their selectivity against cancer cells in a range of tested concentrations.

Preparation of Core–Shell Organic–Inorganic Nanocomposite Particles Based on Phase Separation of a Polymer Blend

Abstract Polymer nanoparticles with phase-separation structures can be prepared by simple solvent evaporation process from block copolymer or polymer blend solution (self-organized precipitation (SORP)). In this report, core–shell organic–inorganic nanocomposite particles were prepared by combination of block copolymer stabilizing Au nanoparticles and polymer blend. Block copolymer stabilizing Au NPs were prepared by reduction of Au ion in their micelles. Nanocomposite particles of poly(methyl methacrylate) (PMMA) and block copolymer stabilizing Au NPs are successfully prepared by using the SORP method.