Poloxamine/fibrin hybrid hydrogels for non-viral gene delivery

Abstract

Hydrogels have been widely investigated for localized, sustained gene delivery because of the similarity of their physical properties to native extracellular matrix and their ability to be formed under mild conditions amenable to the incorporation of bioactive molecules. The objective of this study was to develop bioactive hydrogels composed of macromolecules capable of enhancing the efficiency of non-viral vectors. Hybrid hydrogels were prepared by simultaneous enzymatic and Michael-type addition crosslinking of reduced fibrinogen and an acrylated amphiphilic block copolymer, Tetronic T904, in the presence of dithiothreitol (DTT) and thrombin. T904/fibrin hydrogels degraded by surface erosion in the presence of plasmin and provided sustained release of polyplex vectors up to an order of magnitude longer than pure fibrin gel control. In addition, the rate of gel degradation and time-course of polyplex vector release were readily controlled by varying the T904/fibrinogen ratio in the gel composition. When added to transfected neuroblastoma (N2A) cells, both native T904 itself and hydrogel degradation products significantly increased polyplex transfection efficiency with minimal effect on cell viability. To evaluate gel-based transfection, N2A cells encapsulated in small fibrin clusters were covered by or suspended within polyplex-loaded hydrogels. Cells progressively degraded and invaded the hybrid hydrogels, exhibiting increasing gene expression over 2 weeks and then diminishing but persistent gene expression for over 1 month. In conclusion, these results demonstrate that T904/fibrin hybrid hydrogels can be promising tissue engineering scaffolds that provide local, controlled release of non-viral vectors in combination with the generation of bioactive gel degradation products that actively enhance vector efficiency. Copyright © 2014 John Wiley & Sons, Ltd.

Unifying in vitro and in vivo IVT mRNA expression discrepancies in skeletal muscle via mechanotransduction

“…Tissue compliance has also been shown to play an important role in DNA uptake and expression. Multiple studies have shown that plasmids transfected into cells plated on a soft substrate express protein more efficiently than on a stiffer substrate [53,54,55]. Studies reported earlier showed that hydrogels of Elastic modulus of 10 kPa…”

“…ECM protein crosslinking and stiffening leads to progression of tumors in breast cancer via integrin signaling [52]. The transfection efficiency of polyplexes is highly enhanced by matrix stiffness [53,54,55].…”

“…According to our findings, the difference in stiffness of glass and the hydrogels may explain the differences between the results obtained in vitro and in vivo, indicating that hydrogels may represent a suitable tool for the initial characterization, in vitro, of various IVT mRNA/delivery vehicle complexes. Mechanotransduction is known to affects various cellular processes like motility, adhesion, proliferation, migration, apoptosis, and differentiation [45,46,47,48] and to influence the efficiency of plasmid expression [54,55,79]. However, little is known about the effects on the regulation of translational mechanisms upon IVT mRNA delivery.…”

Structure and Rheology of Poloxamine T1107 and Its Nanocomposite Hydrogels with Cyclodextrin-Modified Barium Titanate Nanoparticles

“…5,6 The more well-known linear counterparts of Tetronics -Pluronicare currently undergoing clinical trials with the cancer drug doxorubicin 7 and the recent demonstration of the ability of Tetronics to also inhibit ATP-binding cassette transporters in cancer cell lines, responsible for multidrug resistance, 5 added to their pH-responsiveness, has recently brought them into the spotlight as serious contenders in the biomedical field. 6 Indeed, they have been proposed as water-soluble copolymers for injectable formulations, 8 nanocarriers for drug and gene delivery 9,10 and in tissue engineering for bone regeneration. 11 The introduction of different types of nanoparticles into hydrogels is a successful way to not only improve existing characteristics (such as gel elasticity and toughness), but also add extra functionalities to the hydrogels, [12][13][14] resulting in new, functional materials.…”

Self-Healing Hydrogels as Biomedical Scaffolds for Cell, Gene and Drug Delivery

“…Gene therapy offers the potential to stimulate tissue regeneration and treat disease through the overexpression or silencing of target genes, including cancer and infection [77,78] . Therefore, it is of great significance to combine the genetic agents with appropriate material in a definite and reversible way.…”