Cross-linked gelatin microspheres with continuously tunable degradation profiles for renal tissue regeneration.

Collagen and gelatin-based biomaterials are widely used in tissue engineering applications. Various methods have been reported for the cross-linking of these macromolecules for the purpose of delaying their biodegradation to prolong their in vivo residence (in tissue engineering applications) or tailoring their drug releasing capacity (when used as drug carriers). In this study, a carbodiimide-based cross-linking method, also used in the production of United States Food and Drug Administration-approved products, was employed to obtain differentially cross-linked gelatin beads.

Formulation of selected renal cells for implantation into a kidney.

Delivery of cells to organs has primarily relied on formulating the cells in a nonviscous liquid carrier. We have developed a methodology to isolate selected renal cells (SRC) that have provided functional stability to damaged kidneys in preclinical models (Kelley et al. Poster presentation at 71st scientific sessions of American diabetes association , 2011; Kelley et al.

Characterization of a PGA-based scaffold for use in a tissue-engineered neo-urinary conduit.

A tissue-engineered product needs to be properly characterized in order to be used in vivo. Many methods can be used to characterize a scaffold during creation of a tissue-engineered product. This chapter looks at the mechanical (tensile testing) and biological characterization (cell viability and proliferation) of a polyglycolic acid-based scaffold used to tissue engineer a Neo-Urinary Conduit™.

Design, fabrication, and preparation of synthetic scaffolds for urologic tissue engineering.

This chapter describes the fabrication of a polyglycolic acid (PGA)-based scaffold used to tissue engineer a Neo-Urinary Conduit™.

Preparation and evaluation of natural scaffold materials for kidney regenerative applications.

Tissue engineering involves the concerted action of biomaterials, cells, and growth factors. Kidney -regeneration relies on the same combination of ingredients. Here, we describe an example of gelatin-based biomaterial preparation and its evaluation in the context of kidney biocompatibility and integration.

Development of an injectable, in situ crosslinkable, degradable polymeric carrier for osteogenic cell populations. Part 3. Proliferation and differentiation of encapsulated marrow stromal osteoblasts cultured on crosslinking poly(propylene fumarate).

This study investigated the effect of temporary encapsulation of rat marrow stromal osteoblasts in crosslinked gelatin microparticles on long-term cell proliferation and phenotypic expression for microparticles placed on crosslinking poly(propylene fumarate) (PPF) composites using N-vinyl pyrollidinone (N-VP) as a crosslinking agent over a 28 day time period. Encapsulated cells (ECs) were seeded on actively crosslinking PPF composites 6 min after initiation of the crosslinking reaction, and also on fully crosslinked PPF composites and tissue culture polystyrene controls, with a cell seeding density of 5.3 x 10(4) cells/cm2.

Development of an injectable, in situ crosslinkable, degradable polymeric carrier for osteogenic cell populations. Part 2. Viability of encapsulated marrow stromal osteoblasts cultured on crosslinking poly(propylene fumarate).

The effect of temporary encapsulation of rat marrow stromal osteoblasts in crosslinked gelatin microparticles on cell viability and proliferation was investigated in this study for microparticles placed on a crosslinking poly(propylene fumarate) (PPF) composite over a 7 day time period. Encapsulated cells were seeded on crosslinking PPF composites at times up to 10 min following initiation of the crosslinking reaction, and also on fully crosslinked PPF composites and tissue culture polystyrene controls, with a cell seeding density of 5.3 x 10(4) cells/cm2.

Development of an injectable, in situ crosslinkable, degradable polymeric carrier for osteogenic cell populations. Part 1. Encapsulation of marrow stromal osteoblasts in surface crosslinked gelatin microparticles.

This study investigated the temporary encapsulation of rat marrow stromal osteoblasts in surface crosslinked gelatin microparticles. Cells were encapsulated in uncrosslinked gelatin microparticles of average diameter of 630 microm containing approximately 53 cells. Gelatin microparticles were crosslinked to shell thicknesses of approximately 75 microm via exposure to 1 mM dithiobis(succinimidylpropionate) (DSP) solution for 15 min or 5 mm DSP solution for 5 min for the production of microparticles dispersing approximately 60 min after placement into a physiologic fluid at 37 degrees C.