Polyaniline-polycaprolactone fibers for neural applications: Electroconductivity enhanced by pseudo-doping.

Replenishing neurons in patients with neurodegenerative diseases is one of the ultimate therapies for these progressive, debilitating and fatal diseases. Electrical stimulation can improve neuron stem cell differentiation but requires a reliable nanopatterned electroconductive substrate. Potential candidate substrates are polycaprolactone (PCL) - polyaniline:camphorsulfonic acid (PANI:CSA) nanofibers, but their nanobiophysical properties need to be finetuned.

The effect of electrospun scaffolds on the glycosaminoglycan profile of differentiating neural stem cells.

The use of electrospun scaffolds for neural tissue engineering applications allows a closer mimicry of the native tissue extracellular matrix (ECM), important for the transplantation of cells in vivo. Moreover, the role of the electrospun fiber mat topography on neural stem cell (NSC) differentiation remains to be completely understood. In this work REN-VM cells (NSC model) were differentiated on polycaprolactone (PCL) nanofibers, obtained by wet/wet electrospinning, and on flat glass lamellas.

POLYBENZIMIDAZOLE NANOFIBERS FOR NEURAL STEM CELL CULTURE.

Neurodegenerative diseases compromise the quality of life of increasing numbers of the world's aging population. While diagnosis is possible no effective treatments are available. Strong efforts are needed to develop new therapeutic approaches, namely in the areas of tissue engineering and (DBS).

Evaluation of Autologously Derived Biomaterials and Stem Cells for Bone Tissue Engineering.

Despite progress, clinical translation of tissue engineering (TE) products/technologies is limited. A significant effort is underway to develop biomaterials and cells through a minimally modified process for clinical translation of TE products. Recently, bone marrow aspirate (BMA) was identified as an autologous source of cells for TE applications and is currently being tested in clinical therapies, but the isolation methods need improvement to avoid potential for contamination and increase progenitor cell yield.

Glycosaminoglycan remodeling during chondrogenic differentiation of human bone marrow-/synovial-derived mesenchymal stem/stromal cells under normoxia and hypoxia.

Glycosaminoglycans (GAGs) are major components of cartilage extracellular matrix (ECM), which play an important role in tissue homeostasis not only by providing mechanical load resistance, but also as signaling mediators of key cellular processes such as adhesion, migration, proliferation and differentiation. Specific GAG types as well as their disaccharide sulfation patterns can be predictive of the tissue maturation level but also of disease states such as osteoarthritis. In this work, we used a highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to perform a comparative study in terms of temporal changes in GAG and disaccharide composition between tissues generated from human bone marrow- and synovial-derived mesenchymal stem/stromal cells (hBMSC/hSMSC) after chondrogenic differentiation under normoxic (21% O) and hypoxic (5% O) micromass cultures.

Kartogenin-loaded coaxial PGS/PCL aligned nanofibers for cartilage tissue engineering.

Electrospinning is a valuable technology for cartilage tissue engineering (CTE) due to its ability to produce fibrous scaffolds mimicking the nanoscale and alignment of collagen fibers present within the superficial zone of articular cartilage. Coaxial electrospinning allows the fabrication of core-shell fibers able to incorporate and release bioactive molecules (e.g.

Evaluation of an Engineered Hybrid Matrix for Bone Regeneration via Endochondral Ossification.

Despite its regenerative ability, long and segmental bone defect repair remains a significant orthopedic challenge. Conventional tissue engineering efforts induce bone formation through intramembranous ossification (IO) which limits vascular formation and leads to poor bone regeneration. To overcome this challenge, a novel hybrid matrix comprised of a load-bearing polymer template and a gel phase is designed and assessed for bone regeneration.

Novel Cellulose-Halloysite Hemostatic Nanocomposite Fibers with a Dramatic Reduction in Human Plasma Coagulation Time.

High-performance cellulose-halloysite hemostatic nanocomposite fibers (CHNFs) are fabricated using a one-step wet-wet electrospinning process and evaluated for human plasma coagulation by activated partial thromboplastin time. These novel biocompatible CHNFs exhibit 2.4 times faster plasma coagulation time compared with the industry gold standard QuikClot Combat Gauze (QCG).

Hydroporator: a hydrodynamic cell membrane perforator for high-throughput vector-free nanomaterial intracellular delivery and DNA origami biostability evaluation.

The successful intracellular delivery of exogenous macromolecules is crucial for a variety of applications ranging from basic biology to the clinic. However, traditional intracellular delivery methods such as those relying on viral/non-viral nanocarriers or physical membrane disruptions suffer from low throughput, toxicity, and inconsistent delivery performance and are time-consuming and/or labor-intensive. In this study, we developed a single-step hydrodynamic cell deformation-induced intracellular delivery platform named "hydroporator" without the aid of vectors or a complicated/costly external apparatus.

Histological Criteria that Distinguish Human and Mouse Bone Formed Within a Mouse Skeletal Repair Defect.

The effectiveness of autologous cell-based skeletal repair continues to be controversial in part because in vitro predictors of in vivo human bone formation by cultured human progenitor cells are not reliable. To assist in the development of in vivo assays of human osteoprogenitor potential, a fluorescence-based histology of nondecalcified mineralized tissue is presented that provides multiple criteria to distinguish human and host osteoblasts, osteocytes, and accumulated bone matrix in a mouse calvarial defect model. These include detection of an ubiquitously expressed red fluorescent protein reporter by the implanted human cells, antibodies specific to human bone sialoprotein and a human nuclear antigen, and expression of a bone/fibroblast restricted green fluorescent protein reporter in the host tissue.

Compositional and structural analysis of glycosaminoglycans in cell-derived extracellular matrices.

The extracellular matrix (ECM) is a highly dynamic and complex meshwork of proteins and glycosaminoglycans (GAGs) with a crucial role in tissue homeostasis and organization not only by defining tissue architecture and mechanical properties, but also by providing chemical cues that regulate major biological processes. GAGs are associated with important physiological functions, acting as modulators of signaling pathways regulating several cellular processes such as cell growth and differentiation. Recently, in vitro fabricated cell-derived ECM have emerged as promising materials for regenerative medicine due to their ability of better recapitulate the native ECM-like composition and structure, without the limitations of availability and pathogen transfer risks of tissue-derived ECM scaffolds.

Remodeling of Glycosaminoglycans During Differentiation of Adult Human Bone Mesenchymal Stromal Cells Toward Hepatocytes.

There is a critical need to generate functional hepatocytes to aid in liver repair and regeneration upon availability of a renewable, and potentially personalized, source of human hepatocytes (hHEP). Currently, the vast majority of primary hHEP are obtained from human tissue through cadavers. Recent advances in stem cell differentiation have opened up the possibility to obtain fully functional hepatocytes from embryonic or induced pluripotent stem cells, or adult stem cells.

Biodegradable and Bioactive PCL-PGS Core-Shell Fibers for Tissue Engineering.

Poly(glycerol sebacate) (PGS) has increasingly become a desirable biomaterial due to its elastic mechanical properties, biodegradability, and biocompatibility. Here, we report microfibrous core-shell mats of polycaprolactone (PCL)-PGS prepared using wet-wet coaxial electrospinning. The anticoagulant heparin was immobilized onto the surface of these electrospun fiber mats, and they were evaluated for their chemical, mechanical, and biological properties.

Hybrid extracellular matrix design for cartilage-mediated bone regeneration.

Recapitulating long bone repair through endochondral ossification (EO) is increasingly becoming a more popular approach. A successful EO Process depends greatly on the establishment of a healthy hypertrophic-cartilage template (HCT). The aim of this work is to design a hydrogel system, which closely mimics the extracellular matrix of HCT.

Surprising absence of heparin in the intestinal mucosa of baby pigs.

Heparin, a member of a family of molecules called glycosaminoglycans, is biosynthesized in mucosal mast cells. This important anticoagulant polysaccharide is primarily produced by extraction of the mast cell-rich intestinal mucosa of hogs. There is concern about our continued ability to supply sufficient heparin to support the worldwide growth of advanced medical procedures from the static population of adult hogs used as food animals.

A potential translational approach for bone tissue engineering through endochondral ossification.

Bone defect repair is a significant clinical challenge in orthopedic surgery. Despite tremendous efforts, the majority of the current bone tissue engineering strategies depend on bone formation via intramembranous ossification (IO), which often results in poor vascularization and limited-area bone regeneration. Recently, there has been increasing interest in exploring bone regeneration through a cartilage-mediated process similar to endochondral ossification (EO).

Functionalized carbon nanotube reinforced scaffolds for bone regenerative engineering: fabrication, in vitro and in vivo evaluation.

Designing biodegradable scaffolds with bone-compatible mechanical properties has been a significant challenge in the field of bone tissue engineering and regenerative engineering. The objective of this work is to improve the polymeric scaffold's mechanical strength by compositing it with mechanically superior carbon nanotubes. Poly(lactide-co-glycolide) (PLGA) microsphere scaffolds exhibit mechanical properties in the range of human cancellous bone.

Design, fabrication and in vitro evaluation of a novel polymer-hydrogel hybrid scaffold for bone tissue engineering.

The development of a bone mechanically-compatible and osteoinductive scaffold is important for bone tissue engineering applications, particularly for the repair and regeneration of large area critically-sized bone defects. Although previous studies with weight-bearing scaffolds have shown promising results, there is a clear need to develop better osteoinductive strategies for effective scaffold-based bone regeneration. In this study, we designed and fabricated a novel polymer-hydrogel hybrid scaffold system in which a load-bearing polymer matrix and a peptide hydrogel allowed for the synergistic combination of mechanical strength and great potential for osteoinductivity in a single scaffold.