Targeted delivery of antisense oligodeoxynucleotide by transferrin conjugated pH-sensitive lipopolyplex nanoparticles: a novel oligonucleotide-based therapeutic strategy in acute myeloid leukemia.

Therapeutic use of oligodeoxynucleotides (ODNs) that hybridize to and downregulate target mRNAs encoding proteins that contribute to malignant transformation has a sound rationale, but has had an overall limited clinical success in cancer due to insufficient intracellular delivery. Here we report a development of formulations capable of promoting targeted delivery and enhanced pharmacologic activity of ODNs in acute myeloid leukemia (AML) cell lines and patient primary cells. In this study, transferrin (Tf) conjugated pH-sensitive lipopolyplex nanoparticles (LPs) were prepared to deliver GTI-2040, an antisense ODN against the R2 subunit of ribonucleotide reductase that has been shown to contribute to chemoresistance in AML.

Delivery of antisense oligodeoxyribonucleotide lipopolyplex nanoparticles assembled by microfluidic hydrodynamic focusing.

A multi-inlet microfluidic hydrodynamic focusing (MF) system to prepare lipopolyplex (LP) containing Bcl-2 antisense deoxyoligonucleotide (ODN) was developed and evaluated. The lipopolyplex nanoparticles consist of ODN:protamine:lipids (1:0.3:12.

Delivery of polyethylenimine/DNA complexes assembled in a microfluidics device.

Polyethylenimine (PEI) and plasmid DNA (pDNA) complexes (PEI/pDNA) are nonviral vectors for gene delivery. The conventional method for producing these complexes involves bulk mixing (BM) of PEI and DNA followed by vortexing which at low N/P ratios results in large particle size distribution, low cytotoxicity, and poor gene transfection, while at high N/P ratios it results in small particle size and better gene transfection but high cytotoxicity. To improve size control, gene transfection efficiency, and cytotoxicity, in this study, we used a microfluidic hydrodynamic focusing (MF) device to prepare PEI/pDNA complexes at N/P = 3.

Transferrin receptor targeted lipopolyplexes for delivery of antisense oligonucleotide g3139 in a murine k562 xenograft model.

Purpose: Transferrin (Tf) conjugated lipopolyplexes (LPs) carrying G3139, an antisense oligonucleotide for Bcl-2, were synthesized and evaluated in Tf receptor positive K562 erythroleukemia cells and then in a murine K562 xenograft model.

Materials And Methods: Particle size and Zeta potentials of transferrin conjugated lipopolyplexs containing G3139 (Tf-LP-G3139) were measured by Dynamic Light Scattering and ZetaPALS. In vitro and in vivo sample's Bcl-2 downregulation was analyzed using Western blot and tumor tissue samples also exhibited by immunohistochemistry method.

A novel 3-D model for cell culture and tissue engineering.

A novel method of making microcapsules in a macrocapsule is demonstrated as a 3-D culture system in this article. Mouse embryonic stem (mES) cells as model cells were used in the 3-D culture space, and the cell viability and histological observation were conducted. Furthermore, Oct4 gene expression was evaluated for the undifferentiated status of mES cells in this 3-D model.

Transferrin receptor-targeted lipid nanoparticles for delivery of an antisense oligodeoxyribonucleotide against Bcl-2.

Antisense oligonucleotide G3139-mediated down-regulation of Bcl-2 is a potential strategy for overcoming chemoresistance in leukemia. However, the limited efficacy shown in recent clinical trials calls attention to the need for further development of novel and more efficient delivery systems. In order to address this issue, transferrin receptor (TfR)-targeted, protamine-containing lipid nanoparticles (Tf-LNs) were synthesized as delivery vehicles for G3139.

Gene transfection of mammalian cells using membrane sandwich electroporation.

To avoid safety issues such as immune response and cytotoxicity associated with viruses and liposomes, physical methods have been widely used for either in vivo or ex vivo gene delivery. They are, however, very invasive and often provide limited efficiency. Using pEGFP and pSEAP plasmids and NIH 3T3 fibroblasts as models, we demonstrate a new electroporation-based gene delivery method, called membrane sandwich electroporation (MSE).

New valve and bonding designs for microfluidic biochips containing proteins.

Two major concerns in the design and fabrication of microfluidic biochips are protein binding on the channel surface and protein denaturing during device assembly. In this paper, we describe new methods to solve these problems. A "fishbone" microvalve design based on the concept of superhydrophobicity was developed to replace the capillary valve in applications where the chip surface requires protein blocking to prevent nonspecific binding.

Surface modification for enhancing antibody binding on polymer-based microfluidic device for enzyme-linked immunosorbent assay.

A novel surface treatment method using poly(ethyleneimine) (PEI), an amine-bearing polymer, was developed to enhance antibody binding on the poly(methyl methacrylate) (PMMA) microfluidic immunoassay device. By treating the PMMA surface of the microchannel on the microfluidic device with PEI, 10 times more active antibodies can be bound to the microchannel surface as compared to those without treatment or treated with the small amine-bearing molecule, hexamethylenediamine (HMD). Consequently, PEI surface modification greatly improved the immunoassay performance of the microfluidic device, making it more sensitive and reliable in the detection of IgG.