ABSTRACT
Various scaffolds used in tissue engineering require a controlled biochemical environment to mimic the physiological cell niche. Interfacial polyelectrolyte complexation (IPC) fibers can be used for controlled delivery of various biological agents such as small molecule drugs, cells, proteins and growth factors. The simplicity of the methodology in making IPC fibers gives flexibility in its application for controlled biomolecule delivery. Here, we describe a method of incorporating IPC fibers into two different polymeric scaffolds, hydrophilic polysaccharide and hydrophobic polycaprolactone, to create a multi-component composite scaffold. We showed that IPC fibers can be easily embedded into these polymeric structures, enhancing the capability for sustained release and improved preservation of biomolecules. We also created a composite polymeric scaffold with topographical cues and sustained biochemical release that can have synergistic effects on cell behavior. Composite polymeric scaffolds with IPC fibers represent a novel and simple method of recreating the cellular niche.
Subject(s)
Biocompatible Materials/chemistry , Delayed-Action Preparations/chemistry , Hydrogels/chemistry , Tissue Engineering/instrumentation , Alginates/chemistry , Chitosan/chemistry , Dextrans/chemistry , Glucans/chemistry , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Hydrophobic and Hydrophilic Interactions , Polyesters/chemistry , Tissue Engineering/methodsABSTRACT
Organic nanoparticles (NPs) with aggregation-induced emission (AIE) have been successfully used for tracking bone marrow stromal cells (BMSCs) in rats with ischemic stroke, highlighting the great potential of such fluorescent NPs in understanding the fate of transplanted stem cells for cell-based therapies.
Subject(s)
Cell Tracking , Mesenchymal Stem Cells/metabolism , Nanoparticles/metabolism , Organic Chemicals/chemistry , Animals , Bone Marrow Cells/cytology , Brain/pathology , Cells, Cultured , Disease Models, Animal , Fluorescent Dyes/chemistry , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/cytology , Microscopy, Fluorescence , Nanoparticles/chemistry , Pyrans/chemistry , Rats , Stroke/metabolism , Stroke/pathology , Stroke/therapyABSTRACT
Hydrogels are highly preferred in soft tissue engineering because they recapitulate the hydrated extracellular matrix. Naturally derived polysaccharides, like pullulan and dextran, are attractive materials with which to form hydrophilic polymeric networks due to their non-immunogenic and non-antigenic properties. However, their inherent hydrophilicity prevents adherent cell growth. In this study, we modified pullulan-dextran scaffolds with interfacial polyelectrolyte complexation (IPC) fibers to improve their ability to support adherent cell growth. We showed that the pullulan-dextran-IPC fiber composite scaffold laden with extracellular matrix protein has improved cell adhesion and proliferation compared to the plain polysaccharide scaffold. We also demonstrated the zero-order release kinetics of the biologics bovine serum albumin and vascular endothelial growth factor (VEGF) incorporated in the composite scaffold. Lastly, we showed that the VEGF released from the composite scaffold retained its capacity to stimulate endothelial cell growth. The incorporation of IPC fibers in the pullulan-dextran hydrogel scaffold improved its functionality and biological activity, thus enhancing its potential in tissue engineering applications.
Subject(s)
Cell Proliferation , Dextrans/chemistry , Fibroblasts/metabolism , Glucans/chemistry , Tissue Scaffolds/chemistry , Animals , Cattle , Cell Adhesion/drug effects , Cell Line , Extracellular Matrix Proteins/chemistry , Extracellular Matrix Proteins/pharmacology , Fibroblasts/cytology , Mice , Serum Albumin, Bovine/chemistry , Serum Albumin, Bovine/pharmacology , Vascular Endothelial Growth Factor A/chemistry , Vascular Endothelial Growth Factor A/pharmacologyABSTRACT
Dysfunction in the corneal endothelium, which controls the hydration and transparency of the cornea, is one of the common reasons for transplantation. A tissue-engineered corneal endothelium is of interest for corneal regeneration and for in vitro testing of ocular drugs. In the native environment, corneal endothelial cells interact with the nanotopography of the underlying Descemet's membrane. This study showed that nanotopography enhanced bovine corneal endothelial cell (BCEC) responses, creating a monolayer which resembled the healthy corneal endothelium. Topographies of different geometries were first tested to identify those that would elicit the most significant responses. A BCEC monolayer was then generated on both micro- and nanoscale pillars and wells. The BCEC monolayer cultured on topographies exhibited polygonal geometries with well-developed tight junction proteins. Scanning electron microscopy revealed that cells on pillars showed a higher density of microvilli, which was similar to native corneal endothelium. BCECs on nanopillars displayed a lower coefficient of variation of area (0.31) that was within the range of healthy corneal endothelium. More importantly, a BCEC monolayer cultured on nanopillars also had an enhanced Na(+)/K(+)-ATPase immunofluorescence expression, mRNA upregulation and a higher Na(+)/K(+)-ATPase activity. These results suggest that nanopillar substrate topography may provide relevant topographical cues, which could significantly enhance the formation and function of corneal endothelium.
