We are developing the next generation of optical fibres for endoscopic imaging and sensing. Our imaging fibre bundle is fabricated from OM1 PCVD graded index preforms made for the telecommunications market. Whilst having a lower numerical aperture, the performance of the imaging fibre is shown to be comparable to the current state-of-the-art commercial microendoscopy fibres. In addition, we are developing negative-curvature optical fibres, which exhibit ultra-low silica Raman background. Measuring Raman spectra through an optical fibre is usually complicated by the high intrinsic Raman scatter of the fibre material. Common solutions such as the use of multiple fibres and distal optics are complex and bulky. The single hollow core negative curvature fibre is used for Raman and surface-enhanced Raman spectroscopy sensing with no distal optics while showing a 1000x background reduction compared to conventional fibres.