3D-Printed Fast-Dissolving Oral Dosage Forms via Fused Deposition Modeling Based on Sugar Alcohol and Poly(Vinyl Alcohol)-Preparation, Drug Release Studies and In Vivo Oral Absorption.

Three-dimensional printing technology holds marked promise for the pharmaceutical industry and is now under intense investigation. Most research is aimed at a greater efficiency in printing oral dosage forms using powder bed printing or fused deposition modeling (FDM). Oral dosage forms printed by FDM tend to be hard objects, which reduce the risk of cracking and chipping.

Effect of shear stress on structure and function of polyplex micelles from poly(ethylene glycol)-poly(l-lysine) block copolymers as systemic gene delivery carrier.

Structural stability of polyplex micelles (PMs), prepared from plasmid DNA (pDNA) and poly(ethylene glycol)-b-poly(l-lysine) block catiomer (PEG-PLys), was evaluated in terms of their resistance against shear stress. When exposed to shear stress at magnitudes typically present in the blood stream, structural deterioration was observed in PMs owing to the partial removal of PEG-PLys strands. Eventually, impaired PEG coverage of the polyplex core led to accelerated degradation by nucleases, implying that structural deterioration by shear stress in blood stream may be a major cause of rapid clearance of PMs from blood circulation.

Enhanced gene expression promoted by the quantized folding of pDNA within polyplex micelles.

Selective packaging of plasmid DNA (pDNA) into folded rod or collapsed sphere structures in polyplex micelles was demonstrated by modulating the PLys segment length of poly(ethylene glycol)-block- poly(L-lysine) (PEG-PLys) block catiomers used for micelle formation. The two basic packaging structures correlated well to the integrity of double-stranded DNA contained within the micelles. Rod structures formed by the quantized folding mechanism, which results in dissociation of double-stranded DNA only at each fold.

Antiangiogenic gene therapy of solid tumor by systemic injection of polyplex micelles loading plasmid DNA encoding soluble flt-1.

In this study, a polyplex micelle was developed as a potential formulation for antiangiogenic gene therapy of subcutaneous pancreatic tumor model. Poly(ethylene glycol)-poly(l-lysine) block copolymers (PEG-PLys) with thiol groups in the side chain of the PLys segment were synthesized and applied for preparation of disulfide cross-linked polyplex micelles through ion complexation with plasmid DNA (pDNA) encoding the soluble form of vascular endothelial growth factor (VEGF) receptor-1 (sFlt-1), which is a potent antiangiogenic molecule. Antitumor activity and gene expression of polyplex micelles with various cross-linking rates were evaluated in mice bearing subcutaneously xenografted BxPC3 cell line, derived from human pancreatic adenocarcinoma, and polyplex micelles with optimal cross-linking rate achieved effective suppression of tumor growth.