Nano-calciumphosphate generation with novel surface and chemical features for improvement of cell activity in bone repair and replacement

Ideal biomaterial for bone replacement implanted should be resorbed by osteoclasts, while osteoblastic activity deposits new bone. Electrospun biphasic nanobioceramic scaffolds were synthesized for in vitro testing, contributing to bone tissue engineering.This paper was initially delivered at the Annual Congress of the Biological Sciences Division of the South African Academy for Science and Art, ARC-Plant Protection Research Institute, Roodeplaat, Pretoria, South Africa on 01 October 2010.http://www.satnt.ac.zaam2014ay201

Calciumphosphate scaffolds for bone tissue repair and applications – in vitro characterisation

The purpose of this study was to generate electrospun biphasic nanobioceramic scaffolds for in vitro testing, ultimately contributing to bone tissue engineering.This abstract was initially presented at the annual Biological Sciences Symposium, presented under the protection of the Suid-Afrikaanse Akademie vir Wetenskap en Kuns. The symposium was held at the University of Johannesburg on 01 October 2011.http://www.satnt.ac.z

In vitro osteoclast-like and osteoblast cells' response to electrospun calcium phosphate biphasic candidate scaffolds for bone tissue engineering

Successful long term bone replacement and repair remain a challenge today. Nanotechnology has makes it possible to alter materials’ characteristics and therefore possibly improve on the material itself. In this study, biphasic (hydroxyapatite/β-tricalcium phosphate (HA/β-TCP)) nanobioceramic scaffolds were prepared by the electrospinning technique in order to mimic the extracellular matrix (ECM). Scaffolds were characterised by scanning electron microscopy (SEM) and Attentuated Total Reflectance Fourier Transform Infrared (ATRFTIR). Osteoblasts as well as monocytes that were differentiated into osteoclast-like cells, were cultured separately on the biphasic bioceramic scaffolds for up to 6 days and the proliferation, adhesion and cellular response were determined using lactate dehydrogenase (LDH) cytotoxicity assay, nucleus and cytoskeleton dynamics, analysis of the cell cycle progression, measurement of the mitochondrial membrane potential and the detection of phosphatidylserine expression. SEM analysis of the biphasic bioceramic scaffolds revealed nano fibers spun in a mesh-like scaffold. Results indicate that the biphasic bioceramic electrospun scaffolds are biocompatible and have no significant negative effects on either osteoblasts or osteoclast-like cells in vitro.Council for Scientific and Industrial Research (CSIR), Pretoria, South Africa.http://www.springer.com/materials/journal/10853hb201

Pichia pastoris : a viable expression system for steroidogenic cytochrome P450 enzymes

Thesis (MSc)--Stellenbosch University, 2005.ENGLISH ABSTRACT: This study describes: I. The cloning of the CVP 19 gene and construction of the intracellular expression vector pPIC3.5K-CYP19. II. The transformation of the yeast, Pichia pastoris with the constructed vector. III. The expression ofP450arom in Pichia pastoris. IV. The determination of enzyme activity and isolation of the protein from the Pichia pastoris cells. V. The expression of P450c 17 in Pichia pastoris. VI. The determination of kinetic constants for the conversion of progesterone to 170H-progesterone and 160H-progesterone by P450c17.AFRIKAANSE OPSOMMING: Hierdie studie beskryf: I. Die klonering van die CVP 19 geen en die konstruksie van die intrasellulêre uitdrukkingsplasmied, pPIC3.5K-CYPI9. II. Die transformasie van die gis, Pichia pastoris, met die gekonstrueerde plasmied. III. Die uitdrukking van aromatase in Pichia pastoris. IV. Die bepaling van ensiemaktiwiteit en die isolering van die proteïen vanuit Pichia pastoris. V. Die uitdrukking van P450c17 in Pichia pastoris. VI. Die bepaling van kinetiese konstantes vir die omsetting van progesteroon na 170H-progesteroon en 160H-progesteroon deur P450c17

Calciumphosphate scaffolds for bone tissue repair and applications – <i>in vitro<i/> characterisation

<div style="font-size: 12px; font-family: serif; left: 227.349px; top: 259.024px; transform: scale(1.12257, 1); transform-origin: 0% 0% 0px;" dir="ltr">Konvensioneel was sterk, bio-inerte material nog altyd die fokus vir beenvervanging en</div><div style="font-size: 12px; font-family: serif; left: 227.349px; top: 275.157px; transform: scale(1.07552, 1); transform-origin: 0% 0% 0px;" dir="ltr">beenherstel. Bioaktiwiteit van huidige vervangingsmateriale benodig verbetering om vinniger herstel en beter been herkonstruksie in die pasiënt te verseker.</div