Reda Felfel

Dr. Reda Felfel

Advanced Materials Research Group, University of Nottingham, Nottingham, UK

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2019 in Carbohydrate Polymers
Verified
Journal Article
Closed access
Reda FelfelReda Felfel
Reda Felfel
MGMark J. Gideon-Adeniyi
Mark J. Gideon-Adeniyi
KHKazi M Zakir Hossain
Kazi M Zakir Hossain
GRGeorge A.F. Roberts
George A.F. Roberts
David GrantDavid Grant
David Grant

1 February 2016 in Biomedical Materials
Verified
Journal Article
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PDF file
Reda FelfelReda Felfel
Reda Felfel
LPLeander Poocza
Leander Poocza
MGMiquel Gimeno-Fabra
Miquel Gimeno-Fabra
TMTobias Milde
Tobias Milde
GHGerhard Hildebrand
Gerhard Hildebrand
KLKlaus Liefeith
Klaus Liefeith
The manufacture of 3D scaffolds with specific controlled porous architecture, defined microstructure and an adjustable degradation profile was achieved using two-photon polymerization (TPP) with a size of 2 × 4 × 2 mm 3 . Scaffolds made from poly(D,L-lactide-co- ɛ -caprolactone) copolymer with varying lactic acid (LA) and ɛ -caprolactone (CL) ratios (LC16:4, 18:2 and 9:1) were generated via ring-opening-polymerization and photoactivation. The reactivity was quantified using photo-DSC, yielding a double bond conversion ranging from 70% to 90%. The pore sizes for all LC scaffolds were see 300 μ m and throat sizes varied from 152 to 177 μ m. In vitro degradation was conducted at different temperatures; 37, 50 and 65 °C. Change in compressive properties immersed at 37 °C over time was also measured. Variations in thermal, degradation and mechanical properties of the LC scaffolds were related to the LA/CL ratio. Scaffold LC16:4 showed significantly lower glass transition temperature ( T g ) (4.8 °C) in comparison with the LC 18:2 and 9:1 (see 32 °C). Rates of mass loss for the LC16:4 scaffolds at all temperatures were significantly lower than that for LC18:2 and 9:1. The degradation activation energies for scaffold materials ranged from 82.7 to 94.9 kJ mol −1 . A prediction for degradation time was applied through a correlation between long-term degradation studies at 37 °C and short-term studies at elevated temperatures (50 and 65 °C) using the half-life of mass loss (Time (M 1/2 )) parameter. However, the initial compressive moduli for LC18:2 and 9:1 scaffolds were 7 to 14 times higher than LC16:4 (see 0.27) which was suggested to be due to its higher CL content (20%). All scaffolds showed a gradual loss in their compressive strength and modulus over time as a result of progressive mass loss over time. The manufacturing process utilized and the scaffolds produced have potential for use in tissue engineering and regenerative medicine applications.

1 December 2010 in Journal of Biomaterials Applications
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Journal Article
Closed access
Reda FelfelReda Felfel
Reda Felfel
IAIfty Ahmed
Ifty Ahmed
APAndrew J. Parsons
Andrew J. Parsons
PHPapia Haque
Papia Haque
GWGavin S. Walker
Gavin S. Walker
CRChris D. Rudd
Chris D. Rudd
In this study, bioresorbable phosphate-based glass (PBG) fibers were used to reinforce poly(lactic acid) (PLA). PLA/PBG random mat (RM) and unidirectional (UD) composites were prepared via laminate stacking and compression molding with fiber volume fractions between 14% and 18%, respectively. The percentage of water uptake and mass change for UD composites were higher than the RM composites and unreinforced PLA. The crystallinity of the unreinforced PLA and composites increased during the first few weeks and then a plateau was seen. XRD analysis detected a crystalline peak at 16.6° in the unreinforced PLA sample after 42 days of immersion in phosphate buffer solution (PBS) at 37°C. The initial flexural strength of RM and UD composites was ∼106 and ∼115 MPa, whilst the modulus was ∼6.7 and ∼9 GPa, respectively. After 95 days immersion in PBS at 37°C, the strength decreased to 48 and 52 MPa, respectively as a result of fiber–matrix interface degradation. There was no significant change in flexural modulus for the UD composites, whilst the RM composites saw a decrease of ∼45%. The molecular weight of PLA alone, RM, and UD composites decreased linearly with time during degradation due to chain scission of the matrix. Short fiber pull-out was seen from SEM micrographs for both RM and UD composites.

11 March 2015 in Journal of Materials Science
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Journal Article
Closed access
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Reda FelfelReda Felfel
Reda Felfel
KHKazi M. Zakir Hossain
Kazi M. Zakir Hossain
APAndrew J. Parsons
Andrew J. Parsons
CRChris D. Rudd
Chris D. Rudd
IAIfty Ahmed
Ifty Ahmed

1 October 2011 in Journal of the Mechanical Behavior of Biomedical Materials
Verified
Journal Article
Closed access
Reda FelfelReda Felfel
Reda Felfel
IAIfty Ahmed
Ifty Ahmed
APA.J. Parsons
A.J. Parsons
GWG.S. Walker
G.S. Walker
CRC.D. Rudd
C.D. Rudd

7 February 2018 in Macromolecular Materials and Engineering
Verified
Journal Article
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PDF file
KHKazi M Zakir Hossain
Kazi M Zakir Hossain
Reda FelfelReda Felfel
Reda Felfel
POPrince S. Ogbilikana
Prince S. Ogbilikana
DTDhruma Thakker
Dhruma Thakker
David GrantDavid Grant
David Grant
IAIfty Ahmed
Ifty Ahmed