planar-gradient-diffusion-system-to-investigate-chemotaxis-3d

Planar Gradient Diffusion System to Investigate Chemotaxis in a 3D Collagen Matrix

The importance of cell migration can be seen through the development of human life. When cells migrate, they generate forces and transfer these forces to ...

The objective of the present in vitro research was to investigate cardiac tissue cell functions (specifically cardiomyocytes and neurons) on poly(lactic-co-glycolic acid) (PLGA) (50:50 wt.%)-carbon nanofiber (CNF) composites to ascertain their potential for myocardial tissue engineering applications. CNF were added to biodegradable PLGA to increase the conductivity and cytocompatibility of pure PLGA. For this reason, different PLGA:CNF ratios (100:0, 75:25, 50:50, 25:75, and 0:100 wt.%) were used and the conductivity as well as cytocompatibility of cardiomyocytes and neurons were assessed. Scanning electron microscopy, X-ray diffraction and Raman spectroscopy analysis characterized the microstructure, chemistry, and crystallinity of the materials of interest to this study. The results show that PLGA:CNF materials are conductive and that the conductivity increases as greater amounts of CNF are added to PLGA, from 0 S m(-1) for pure PLGA (100:0 wt.%) to 5.5×10(-3) S m(-1) for pure CNF (0:100 wt.%). The results also indicate that cardiomyocyte density increases with greater amounts of CNF in PLGA (up to 25:75 wt.% PLGA:CNF) for up to 5 days. For neurons a similar trend to cardiomyocytes was observed, indicating that these conductive materials promoted the adhesion and proliferation of two cell types important for myocardial tissue engineering applications. This study thus provides, for the first time, an alternative conductive scaffold using nanotechnology which should be further explored for cardiovascular applications.

Poly(lactic-co-glycolic acid): carbon nanofiber composites for myocardial tissue engineering applications.

The objective of the present in vitro study was to investigate cardiomyocyte functions, specifically their adhesion and proliferation, on injectable scaffolds containing RNT (rosette nanotubes) and CNF (carbon nanofibers) in a pHEMA (poly(2-hydroxyethyl methacrylate)) hydrogel to determine their potential for myocardial tissue engineering applications. RNTs are novel biocompatible nanomaterials assembled from synthetic analogs of DNA bases guanine and cytosine that self-assemble within minutes when placed in aqueous solutions at body temperatures. These materials could potentially improve cardiomyocyte functions and solidification time of pHEMA and CNF composites. Because heart tissue is conductive, CNFs were added to pHEMA to increase the composite's conductivity. Our results showed that cardiomyocyte density increased after 4 h, 1 day, and 3 days with greater amounts of CNFs and greater amounts of RNTs in pHEMA (up to 10 mg mL(-1) CNFs and 0.05 mg mL(-1) RNTs). Factors that may have increased cardiomyocyte functions include greater wettability, conductivity, and an increase in surface nanoroughness with greater amounts of CNFs and RNTs. In effect, contact angles measured on the surface of the composites decreased while the conductivity and surface roughness increased as CNFs and RNTs content increased. Lastly, the ultimate tensile modulus decreased for composites with greater amounts of CNFs. In summary, the properties of these injectable composites make them promising candidates for myocardial tissue engineering applications and should be further studied. Â© 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.

Novel injectable biomimetic hydrogels with carbon nanofibers and self assembled rosette nanotubes for myocardial applications.

Das Ziel der vorliegenden in-vitro-Studie war zu untersuchen Cardiomyocyte Funktionen, speziell ihre Haftung und Verbreitung auf injizierbaren Ger&uuml;ste, RNT (Rosette Nanotubes) und CNF (Kohlenstoff Nanofasern) enth&auml;lt in einem Hydrogel pHEMA (Poly (2-Hydroxyethyl-Methacrylat)) ihr Potenzial f&uuml;r myokardiale Tissue-engineering Anwendungen bestimmt. RNTs sind neuartige biokompatible Nanomaterialien, zusammengesetzt aus synthetischen Analoga der DNA-Basen Guanin und Cytosin d. self-assemble innerhalb von Minuten, wenn Sie in w&auml;ssrigen L&ouml;sungen bei K&ouml;rpertemperatur gelegt. Diese Materialien k&ouml;nnte potenziell Cardiomyocyte Funktionen Erstarrungszeit von pHEMA und CNF Composites verbessern. Da Herzgewebe leitf&auml;hig ist, wurden CNFs pHEMA der Composite-Leitf&auml;higkeit erh&ouml;hen hinzugef&uuml;gt. Unsere Ergebnisse zeigten, dass Cardiomyocyte Dichte nach 4 Stunden, 1 Tag und 3 Tage gr&ouml;&szlig;ere Mengen von CNFs und gr&ouml;&szlig;ere Mengen an RNTs in pHEMA (bis zu 10 mg mL(-1) CNFs und 0,05 mg mL(-1) RNTs) erh&ouml;ht. Faktoren, die Cardiomyocyte Funktionen erh&ouml;ht haben k&ouml;nnen sind gr&ouml;&szlig;ere Benetzbarkeit, Leitf&auml;higkeit und eine Steigerung in Oberfl&auml;che Nanoroughness in gr&ouml;&szlig;eren Mengen, CNFs und RNTs. Kontaktieren Sie im Endeffekt Winkel gemessen auf der Oberfl&auml;che der Composites zur&uuml;ckgegangen, w&auml;hrend die Leitf&auml;higkeit und Rauheit der Oberfl&auml;che als CNFs erh&ouml;ht und RNTs Inhalt erh&ouml;ht. Schlie&szlig;lich sank das ultimative Elastizit&auml;tsmodul f&uuml;r Composites in gr&ouml;&szlig;eren Mengen von CNFs. Zusammenfassend l&auml;sst sich sagen die Eigenschaften dieser injizierbaren Composites machen Ihnen vielversprechende Kandidaten f&uuml;r myokardiale Tissue-engineering Anwendungen und sollte weiter untersucht werden. &copy; 2012 Wiley Periodika, Inc. J Biomed Mater Res Teil A, 2012.

Neuartige injizierbare biomimetische Hydrogele mit Kohlenstoff Nanofasern und selbst zusammengebaut Rosette Nanotubes f&uuml;r myokardiale Anwendungen.

Recent advances in nanotechnology (materials with at least one dimension between 1 nm and 100 nm) have led to the use of nanomaterials in numerous medical device applications. Recently, nanomaterials have been used to create innovative biomaterials for cardiovascular applications. Specifically, carbon nanofibers (CNF) embedded in poly(lactic-co-glycolic-acid) (PLGA) have been shown to promote cardiomyocyte growth compared with conventional polymer substrates, but the mechanisms involved in such events remain unknown. The aim of this study was to determine the basic mechanism of cell growth on these novel nanocomposites.

Mechanisms of greater cardiomyocyte functions on conductive nanoengineered composites for cardiovascular application.

Due to their superior cytocompatible, mechanical, electrical, optical, catalytic, and magnetic properties, nanomaterials (materials with one dimension ≤100 nm) have been investigated intensely for numerous medical applications including, most notably, as improved tissue engineering materials and in situ sensors. In particular, compared to conventional materials (materials without one dimension ≤100 nm) used for orthopedic applications, nanomaterials have demonstrated an enhanced capability to restore, maintain, and improve bone tissue formation while inhibiting inflammation and infection. This review article elucidates several promising examples of nanomaterials (including polymers, metals, and ceramics) to improve musculoskeletal implant performance in terms of enhanced bone cell functions, reduced inflammation, and inhibiting infection. With respect to the emergence of tissue engineering in orthopedic applications, this review summarizes recent efforts to develop nanostructured polymers and self-assembled nano-materials, which have improved bone growing properties than traditional permanent orthopedic medical devices.

The nano-effect: improving the long-term prognosis for musculoskeletal implants.

During a heart attack, the heart's oxygen supply is cut off, and cardiomyocytes perish. Unfortunately, once these tissues are lost, they cannot be replaced and results in cardiovascular disease-the leading cause of deaths worldwide. Advancements in medical research have been targeted to understand and combat the death of these cardiomyocytes. For example, new research (in vitro) has demonstrated that one can expand cardiomyocyte adhesion and proliferation using polylactic-co-glycolic acid (PLGA) (50:50 (weight percent)) supplemented with carbon nanofibers (CNFs) to create a cardiovascular patch. However, the examination of other cardiovascular cell types has not been investigated. Therefore, the purpose of this present in vitro study was to determine cell growth characteristics of three different important cardiovascular cell types (aortic endothelial, fibroblast and cardiomyocyte) onto the substrate. Cells were seeded onto different PLGA:CNF ratio composites to determine if CNF density has an effect on cell growth, both in static and electrically stimulated environments. During continuous electrical stimulation (rectangle, 2 nm, 5 V/cm, 1 Hz), cardiomyocyte cell density increased in comparison to its static counterparts after 24, 72 and 120 hours. A minor rise in Troponin I excretion in electrical stimulation compared to static conditions indicated nominal cardiomyocyte cell function during cell experiments. Endothelial and fibroblast cell growth experiments indicated the material hindered or stalled proliferation during both static and electrical stimulation experiments, thus supporting the growth of cardiomyocytes onto the dead tissue zone. Furthermore, the results specified that CNF density did have an effect on PLGA:CNF composite cytocompatibility properties with the best results coming from the 50:50 [PLGA:CNF (weight percent:weight percent)] composite. Therefore, this study provides further evidence that a conductive scaffold using nanotechnology should be further research for various cardiovascular applications.

Growth characteristics of different heart cells on novel nanopatch substrate during electrical stimulation.

Since the discovery and synthesis of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) over a decade ago, researchers have envisioned and discovered new potential applications for these materials. CNTs and CNFs have rapidly become a platform technology for a variety of uses, including biomedical applications due to their mechanical, electrical, thermal, optical and structural properties. CNTs and CNFs are also advantageous due to their ability to be produced in many different shapes and sizes. Since their discovery, of the many imaginable applications, CNTs and CNFs have gained a significant amount of attention and therapeutic potential in tissue engineering and drug delivery applications. In recent years, CNTs and CNFs have made significant contributions in designing new strategies for, delivery of pharmaceuticals, genes and molecular probes into cells, stem cell therapies and assisting in tissue regeneration. Furthermore, it is widely expressed that these materials will significantly contribute to the next generation of health care technologies in treating diseases and contributing to tissue growth. Hence, this review seeks to explore the recent advancements, current status and limitations of CNTs and CNFs for drug delivery and tissue engineering applications.

Article	Year
Poly(lactic-co-glycolic acid): carbon nanofiber composites for myocardial tissue engineering applications. Acta biomaterialia\| PubMed ID: 21571106	2011
Novel injectable biomimetic hydrogels with carbon nanofibers and self assembled rosette nanotubes for myocardial applications. Journal of biomedical materials research. Part A\| PubMed ID: 23008178	2012
Mechanisms of greater cardiomyocyte functions on conductive nanoengineered composites for cardiovascular application. International journal of nanomedicine\| PubMed ID: 23180962	2012
The nano-effect: improving the long-term prognosis for musculoskeletal implants. Journal of long-term effects of medical implants\| PubMed ID: 23582111	2012
Growth characteristics of different heart cells on novel nanopatch substrate during electrical stimulation. Bio-medical materials and engineering\| PubMed ID: 25226907	2014
Recent advancements in carbon nanofiber and carbon nanotube applications in drug delivery and tissue engineering. Current pharmaceutical design\| PubMed ID: 25732658	2015

David A. Stout

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