Three-Dimensional Electrodeposition of Calcium Phosphates on Porous Nanofibrous Scaffolds and Their Controlled Release of Calcium for Bone Regeneration.

To mimic the bone matrix of mineralized collagen and to impart microporous structure to facilitate cell migration and bone regeneration, we developed a nanofibrous (NF) polymer scaffold with highly interconnected pores and three-dimensional calcium phosphate coating utilizing an electrodeposition technique. The mineral content, morphology, crystal structure, and chemical composition could be tailored by adjusting the deposition temperature, voltage, and duration. A higher voltage and a higher temperature led to a greater rate of mineralization.

Pore size directs bone marrow stromal cell fate and tissue regeneration in nanofibrous macroporous scaffolds by mediating vascularization.

In the U.S., 30% of adults suffer joint pain, most commonly in the knee, which severely limits mobility and is often attributed to injury of cartilage and underlying bone in the joint.

Nanofibrous spongy microspheres enhance odontogenic differentiation of human dental pulp stem cells.

Dentin regeneration is challenging due to its complicated anatomical structure and the shortage of odontoblasts. In this study, a novel injectable cell carrier, nanofibrous spongy microspheres (NF-SMS), is developed for dentin regeneration. Biodegradable and biocompatible poly(l-lactic acid)-block-poly(l-lysine) are synthesized and fabricated into NF-SMS using self-assembly and thermally induced phase separation techniques.

Injectable Peptide Decorated Functional Nanofibrous Hollow Microspheres to Direct Stem Cell Differentiation and Tissue Regeneration.

Injectable microspheres are attractive stem cell carriers for minimally invasive procedures. For tissue regeneration, the microspheres need to present the critical cues to properly direct stem cell differentiation. In natural extracellular matrix (ECM), growth factors (GFs) and collagen nanofibers provide critical chemical and physical cues.

Gene therapy for nucleus pulposus regeneration by heme oxygenase-1 plasmid DNA carried by mixed polyplex micelles with thermo-responsive heterogeneous coronas.

Safe and high-efficiency gene therapy for nucleus pulposus (NP) regeneration was urgently desired to treat disc degeneration-associated diseases. In this work, an efficient nonviral cationic block copolymer gene delivery system was used to deliver therapeutic plasmid DNA (pDNA), which was prepared via complexation between the mixed cationic block copolymers, poly(ethylene glycol)-block-poly{N-[N-(2-aminoethyl)-2-aminoehtyl]aspartamide} [PEG-b-PAsp(DET)] and poly(N-isopropylacrylamide)-block-PAsp(DET) [PNIPAM-b-PAsp(DET)], and pDNA at 25 °C. The mixed polyplex micelles (MPMs) containing heterogeneous coronas with hydrophobic and hydrophilic microdomains coexisting could be obtained upon heating from 25 to 37 °C, which showed high tolerability against nuclease and strong resistance towards protein adsorption.

Hypoxia promotes nucleus pulposus phenotype in 3D scaffolds in vitro and in vivo: laboratory investigation.

Object: The role of oxygen in disc metabolism remains a matter of debate. Whether the effect of hypoxic priming on the nucleus pulposus phenotype can be maintained in vivo is not clear. The goal of the present study was to test the hypothesis that priming in a low oxygen tension in vitro could promote a nucleus pulposus phenotype in vivo.

Biomaterials and stem cells for tissue engineering.

Introduction: Organ failure and tissue loss are challenging health issues due to widespread injury, the lack of organs for transplantation and limitations of conventional artificial implants. The field of tissue engineering aims to provide alternative living substitutes that restore, maintain or improve tissue function.

Areas Covered: In this paper, a wide range of porous scaffolds are reviewed, with an emphasis on phase-separation techniques that generate advantageous nanofibrous 3D scaffolds for stem cell-based tissue engineering applications.

Regenerating nucleus pulposus of the intervertebral disc using biodegradable nanofibrous polymer scaffolds.

Low back pain is a leading health problem in the United States, which is most often resulted from nucleus pulposus (NP) degeneration. To date, the replacement of degenerated NP relies entirely on mechanical devices. However, a biological NP replacement implant is more desirable.

Effects of hypoxias and scaffold architecture on rabbit mesenchymal stem cell differentiation towards a nucleus pulposus-like phenotype.

Nucleus pulposus grafts are needed for patients requiring replacement of their degenerated intervertebral discs. Bone marrow-derived mesenchymal stem cells (MSCs) are a potential autologous stem cell source for the nucleus pulposus regeneration. One of the key issues of constructing functional nucleus pulposus using MSCs, however, is to differentiate MSCs into nucleus pulposus phenotype in vitro and to maintain their phenotypic stability in vivo.