Microporous annealed particle hydrogel stiffness, void space size, and adhesion properties impact cell proliferation, cell spreading, and gene transfer.

Designing scaffolds for polyplex-mediated therapeutic gene delivery has a number of applications in regenerative medicine, such as for tissue repair after wounding or disease. Microporous annealed particle (MAP) hydrogels are an emerging class of porous biomaterials, formed by annealing microgel particles to one another in situ to form a porous bulk scaffold. MAP gels have previously been shown to support and enhance proliferative and regenerative behaviors both in vitro and in vivo.

Pathways Governing Polyethylenimine Polyplex Transfection in Microporous Annealed Particle Scaffolds.

Gene delivery using injectable hydrogels can serve as a potential method for regulated tissue regeneration in wound healing. Our microporous annealed particle (MAP) hydrogel has been shown to promote cellular infiltration in both skin and brain wounds, while reducing inflammation. Although the scaffold itself can promote healing, it is likely that other signals will be required to promote healing of hard-to-treat wounds.

Hyaluronic acid hydrogel scaffolds loaded with cationic niosomes for efficient non-viral gene delivery.

The lack of ideal non-viral gene carriers has motivated the combination of delivery systems and tissue-engineered scaffolds, which may offer relevant advantages such as enhanced stability and reduced toxicity. In this work, we evaluated a new combination between niosome non-viral vectors and hyaluronic acid (HA) hydrogel scaffolds, both widely studied due to their biocompatibility as well as their ability to incorporate a wide variety of molecules. We evaluated three different niosome formulations (niosomes , and ) varying in composition of cationic lipid, helper lipid and non-ionic tensioactives.

It's All in the Delivery: Designing Hydrogels for Cell and Non-viral Gene Therapies.

Hydrogels provide a regenerative medicine platform with their ability to create an environment that supports transplanted or endogenous infiltrating cells and enables these cells to restore or replace the function of tissues lost to disease or trauma. Furthermore, these systems have been employed as delivery vehicles for therapeutic genes, which can direct and/or enhance the function of the transplanted or endogenous cells. Herein, we review recent advances in the development of hydrogels for cell and non-viral gene delivery through understanding the design parameters, including both physical and biological components, on promoting transgene expression, cell engraftment, and ultimately cell function.

Sustained Transgene Expression via Hydrogel-Mediated Gene Transfer Results from Multiple Transfection Events.

Sustained delivery of therapeutic genes in vitro and in vivo has a wide range of applications in studying biology and in developing therapies for treating disease or repairing tissue. Nonviral vectors such as cationic polymers still present promising approaches; however, bolus transfection methods with polyethylenimine-based DNA polyplexes suffer from considerable levels of cytotoxicity and short-lived transgene expression levels. Here, we designed and characterized a hyaluronic acid-based porous hydrogel system for nonviral gene delivery by loading with surface-associated DNA polyplexes.

Systematic evaluation of natural scaffolds in cutaneous wound healing.

Current strategies to improve wound healing are often created from multiple components that may include a scaffold, cells, and bioactive cues. Acellular natural hydrogels are an attractive approach since the material's intrinsic biological activity can be paired with mechanical properties similar to soft tissue to induce a host's response toward healing. In this report, a systematic evaluation was conducted to study the effect of hydrogel scaffold implantation in skin healing using a human-relevant murine wound healing model.

Encapsulation of PEGylated low-molecular-weight PEI polyplexes in hyaluronic acid hydrogels reduces aggregation.

Unlabelled: The effective delivery of DNA locally could increase the applicability of gene therapy in tissue regeneration and therapeutic angiogenesis. One promising approach is through use of porous hydrogel scaffolds that incorporate and deliver DNA in the form of nanoparticles to the affected sites. While we have previously reported on caged nanoparticle encapsulation (CnE) to load DNA polyplexes within hydrogels at high concentrations without aggregation, frequent issues with limited polyplex release following CnE have been encountered.

Abdominal fat suspension device for maintaining normal cardiorespiratory function in patients undergoing conscious sedation during surgery: a feasibility study.

Obese patients undergoing conscious-sedation surgery have increased perioperative morbidity because their excess abdominal tissue limits diaphragmatic excursion. We describe a simple device that might help attenuate this risk. We created a noninvasive suction device for abdominal suspension.

Design of cell-matrix interactions in hyaluronic acid hydrogel scaffolds.

The design of hyaluronic acid (HA)-based hydrogel scaffolds to elicit highly controlled and tunable cell response and behavior is a major field of interest in developing tissue engineering and regenerative medicine applications. This review will begin with an overview of the biological context of HA, which is needed to better understand how to engineer cell-matrix interactions in the scaffolds via the incorporation of different types of signals in order to direct and control cell behavior. Specifically, recent methods of incorporating various bioactive, mechanical and spatial signals are reviewed, as well as novel HA modifications and crosslinking schemes with a focus on specificity.