Laser sintering (LS) of polymers has high potential for growth as a manufacturing technique into a wide range of applications provided the range of engineering polymers available for LS expands and machines and SLS process conditions are optimised for such materials. This study is the first investigation into laser sintering of both virgin and used polyether ketone PEK powder using a bespoke high temperature polymer laser sintering machine (EOS P800). The physicochemical results reveal that, in spite of polymer degradation, used PEK has a viable processing processing window for LS manufacturing which, combined with optimisation of specific parameters can successfully lead to manufacture of good quality parts. The proposed sintering mechanism of both, virgin and used powders is supported by the experimental data. The incorporation of 30 % used HP3 PEK powder led to an approximately 17% drop in tensile strength. Virgin PEK (~41% crystallinity)Used PEK (~52% crystallinity ) Shorter chainsCross-linked region First investigation into laser sintering of virgin and used polyether ketones (PEK) using a bespoke high temperature selective laser sintering system The incorporation of 30 % used PEK powder led to an approximately 17% drop in tensile strength The use of a higher laser power improves the surface finish but it doesn't affect the porosity and mechanical strength of the parts incorporating reused powder The used PEK powder suffers degradation which affects the particle coalescence process This study is the first investigation into laser sintering of both virgin and used polyether ketone PEK powder using a bespoke high temperature (HT) polymer laser sintering machine (known commercially as EOSINT P800). The physico-chemical results reveal that, in spite of polymer degradation, used PEK has a viable processing window for LS manufacturing which, combined with optimisation of specific parameters can successfully lead to manufacture of good quality parts. The proposed sintering mechanism of both, virgin and used powders is supported by the experimental data. The incorporation of 30 % used HP3 PEK powder led to an approximately 17% drop in tensile strength.

Triple negative breast cancer (TNBC) is a heterogeneous disease, which lacks expression of the estrogen receptor (ER), progesterone receptor (PR) and the human epidermal growth factor 2 receptor (HER2). This subtype of breast cancer has the poorest prognosis with limited therapies currently available, and hence additional options are needed. CAPER is a coactivator of the activator protein-1 (AP-1) (interacting specifically with the c-Jun component) and the ER and is known to be involved in human breast cancer pathogenesis. Recent published data have demonstrated a role for CAPER in TNBC and, as such, disrupting the function of CAPER with c-Jun could be a novel approach to treat TNBC patients. The data presented here shows the development and in vitro testing of CAPER-derived peptides that inhibit the coactivator activity of CAPER with c-Jun. These CAPER peptides result in a decrease in cell number and an increase in apoptosis in two TNBC cell lines, MDA-MB-231 and BT-549, while having no effect on the non-tumorigenic cell line MCF 10A. Additionally, two modes of action were demonstrated which appear to be cell line dependent: 1) a modulation of phosphorylated c-Jun leading to a decrease in Bcl-2 in MDA-MB-231 cells and a decrease in p21 in BT-549 cells and 2) a decrease in DNA repair proteins, leading to impaired DNA repair function in MDA-MB-231 cells. The data presented here supports further development of CAPER-derived peptides for the treatment of TNBC.