rian.ie - Browse

Author(s)
Institution
Publication types
Funder
Year

Limited By:	Subject = Polycaprolactone;

6 items found

Sort by

Order

per page

Displaying Results 1 - 6 of 6 on page 1 of 1

Marked Mark

A method to fabricate small features on scaffolds for tissue engineering via selective laser sintering (2013)

Lohfeld, Stefan; Tyndyk, M.A.; Cahill, S.; Flaherty, N.; Barron, Valerie; McHugh, Peter

A method to fabricate small features on scaffolds for tissue engineering via selective laser sintering (2013)

Lohfeld, Stefan; Tyndyk, M.A.; Cahill, S.; Flaherty, N.; Barron, Valerie; McHugh, Peter

Abstract:

Purpose:Selective laser sintering (SLS) is a rapid prototyping technique applied to produce tissue-engineering scaffolds from powder materials. The standard scanning technique, however, often produces struts of extensive thickness, which means fabrication of highly porous scaffolds with small overall dimensions is quite difficult. Nevertheless, this study aims to overcome this shortfall. Design/methodology/approach:To this end, three scanning methods were evaluated in terms of minimum feature size and freedom of design, using a test polyamide (PA) material. Polycaprolactone (PCL) was then employed to create highly porous 3D scaffolds using the preferred scanning method to produce thin struts.Findings:While in normal scanning mode some features were well above the laser spot diameter, strut thicknesses below the laser spot diameter were achieved when using the outline scan function for PA material. Those achieved for PCL were slightly higher and in the 500-800 µm range, with an ave...

http://hdl.handle.net/10379/3664

Marked Mark

Evaluating the effect of increasing ceramic content on the mechanical properties, material microstructure and degradation of selective laser sintered PCL/b-TCP materials (2016)

Doyle, Heather; Lohfeld, Stefan; McHugh, Peter E.

Evaluating the effect of increasing ceramic content on the mechanical properties, material microstructure and degradation of selective laser sintered PCL/b-TCP materials (2016)

Doyle, Heather; Lohfeld, Stefan; McHugh, Peter E.

Abstract:

Orthopaedic scaffold materials were fabricated from polycaprolactone (PCL) and composite PCL β-tricalcium phosphate (PCL/β-TCP) powders using selective laser sintering (SLS). Incorporating β-TCP particles is desirable to promote osteogenesis. The effects of increasing β-TCP content on the material s mechanical properties and microstructure were evaluated. The wt% of β-TCP and PCL particle sizes were found to inﬂuence material microstructure and mechanical properties, with increasing ceramic content causing a small but signiﬁcant increase in stiffness but signiﬁcant reductions in strength. Degradation of materials was achieved using ac- celerated ageing methods. The inﬂuence of β-TCP content on degradation at 7 weeks was evaluated through changes in mechanical properties and microstructure, and the ceramic particles were found to reduce elastic modulus and increase strength. The results ...

http://hdl.handle.net/10379/6004

Marked Mark

Evaluation of a multiscale modelling methodology to predict the mechanical properties of PCL/β-TCP sintered scaffold materials (2016)

Doyle, Heather; Lohfeld, Stefan; McDonnell, Pat; McHugh, Peter E.

Evaluation of a multiscale modelling methodology to predict the mechanical properties of PCL/β-TCP sintered scaffold materials (2016)

Doyle, Heather; Lohfeld, Stefan; McDonnell, Pat; McHugh, Peter E.

Abstract:

A multiscale modelling methodology to predict the macroscale stiffness of selective laser sintered polycaprolactone (PCL)/β-tricalcium phosphate (β-TCP) materials is evaluated. The relationship between a micromechanics-evaluated composite material elastic modulus (Eeff) and segment grey-value (GVave) is established for a 90/10 wt% PCL/β-TCP material and compared to the previously established Eeff vs. GVave relationship for a 50/50 wt% PCL/β-TCP material. The increase in Eeff with GVave was found to be greater for the 90/10 wt% material than for the 50/50 wt% material. Differences in the material microstructures are visible with greater local conglomerations of β-TCP in the 90/10 wt% material compared to the 50/50 wt% material. These results indicate that the relationship between Eeff and GVave is material-specific and that one definition cannot be used to describe both materials. We have used the Eeff and GVave relationship specific to the 90/10 wt% material to assign element-specif...

http://hdl.handle.net/10379/6029

Marked Mark

Fiber Reinforced Cartilage ECM Functionalized Bioinks for Functional Cartilage Tissue Engineering (2019)

Moebius, Matthias; Kelly, Daniel; Rathan, Swetha; Dejob, L?a; Schipani, Rossana; Haffne...

Fiber Reinforced Cartilage ECM Functionalized Bioinks for Functional Cartilage Tissue Engineering (2019)

Moebius, Matthias; Kelly, Daniel; Rathan, Swetha; Dejob, L?a; Schipani, Rossana; Haffner, Benjamin

Abstract:

Focal articular cartilage (AC) defects, if left untreated, can lead to debilitating diseases such as osteoarthritis. While several tissue engineering strategies have been developed to promote cartilage regeneration, it is still challenging to generate functional AC capable of sustaining high load-bearing environments. We developed a new class of cartilage extracellular matrix (cECM)-functionalized alginate bioink for the bioprinting of cartilaginous tissues. The bioinks were 3D-printable, supported mesenchymal stem cell (MSC) viability post-printing and robust chondrogenesis in vitro, with the highest levels of COLLII and ACAN expression observed in bioinks containing the highest concentration of cECM. Enhanced chondrogenesis in cECM-functionalized bioinks was also associated with progression along an endochondral-like pathway, as evident by increases in RUNX2 expression and calcium deposition in vitro. The bioinks loaded with MSCs and TGF-?3 were also found capable of supporting ro...

http://hdl.handle.net/2262/91275

Marked Mark

Genomics approaches to exploit the biotechnological potential of marine sponge-derived Streptomyces spp. isolates (2019)

Almeida, Eduardo L.

Genomics approaches to exploit the biotechnological potential of marine sponge-derived Streptomyces spp. isolates (2019)

Almeida, Eduardo L.

Abstract:

Members of the Streptomyces genus are widely known for their capability in producing compounds of pharmacological, clinical, and biotechnological interest, being the source of approximately a third of all the antibiotics that have been identified to date. However, the discovery of natural products with antimicrobial activities has declined following the so-called “Golden Age of Antibiotics” (1940s-1950s), particularly due to the common re-discovery of previously known compounds. Thus, natural products discovery research has shifted towards investigating diverse environmental niches, such as marine ecosystems, mangroves, and symbiotic communities of insects and sponges, resulting in the discovery of a variety of previously unidentified compounds of pharmacological interest; including those isolated from marine-derived Streptomyces species. However, in despite of their relevance as producers of potentially novel bio-active molecules with pharmacological, clinical and biotechnological ...

http://hdl.handle.net/10468/9923

Marked Mark

Reinforcing interpenetrating network hydrogels with 3D printed polymer networks to engineer cartilage mimetic composites (2020)

Kelly, Daniel

Reinforcing interpenetrating network hydrogels with 3D printed polymer networks to engineer cartilage mimetic composites (2020)

Kelly, Daniel

Abstract:

Engineering constructs that mimic the complex structure, composition and biomechanics of the articular cartilage represents a promising route to joint regeneration. Such tissue engineering strategies require the development of biomaterials that mimic the mechanical properties of articular cartilage whilst simultaneously providing an environment supportive of chondrogenesis. Here three-dimensional (3D) bioprinting is used to develop polycaprolactone (PCL) fibre networks to mechanically reinforce interpenetrating network (IPN) hydrogels consisting of alginate and gelatin methacryloyl (GelMA). Inspired by the significant tension-compression nonlinearity of the collagen network in articular cartilage, we printed reinforcing PCL networks with different ratios of tensile to compressive modulus. Synergistic increases in compressive modulus were observed when IPN hydrogels were reinforced with PCL networks that were relatively soft in compression and stiff in tension. The resulting composit...

http://hdl.handle.net/2262/93558

Displaying Results 1 - 6 of 6 on page 1 of 1