@ckoei – No, definitely no needle sharpening for me, not even any syringe boiling. To ensure syringe (& needle) sterility, I had what was supposed to be a system for travelling with your injection kit, but because it was so compact, convenient and hassle free, I used it continuously. (prepare for yet another trip down diabetes technology memory lane)
It consisted of a dull silver-coloured metal box (aluminium I suspect) about 25mm x 80mm x 120mm with a hinged lid. Inside that was a white plastic insert with cut outs for storing your insulin bottles, needles and a grey plastic tube that contained your syringe (with needle attached if required) and enough surgical spirit to kill any bacteria within a half mile radius. This meant that as long as you kept the surgical spirit topped-up, you had a ;