The transition between muscle and bone in vivo is mediated by tendon, which acts to eliminate the impedance mismatch and stress concentrations present between the compliant muscle and the stiff bone. The force produced by muscle contraction is transmitted first through the myotendinous junction, then through parallel collagen fibres of the tendon and finally through the enthesis or osteotendinous junction. All three of these structures have been shown to differ in mechanical properties along their length, resulting in a smooth transfer of force between structures. Currently, the method used to engineer skeletal muscle involves the use of silk sutures to anchor the muscle construct, providing an attachment point to allow functional testing or stretching of the constructs. However, due to the impedance mismatch between the muscle and the suture, the muscles detach from their anchor points under stretch. The aim of this study is to produce a cell-embedded scaffold to function as a muscle-machine interface. Scaffolds consisting of polyethylene glycol diacrylate (PEGDA) hydrogels, incorporated with the cell adhesion peptide GRGDS to improve cell attachment and structurally reinforced with hydroxyapatite (HA) were produced for this purpose by UV crosslinking. The addition of HA alone or in combination with GRGDS did not affect the swelling properties of the hydrogel with the average length increasing by 41.1±10.6% and width increasing by 142.1±17.9% after 7 days in growth media. To test the biocompatibility of the gels, PEGDA-HA, PEGDA-GRGDS and PEGDA-GRGDS-HA hydrogels were seeded with primary tendon fibroblasts and cell counts were performed at 6, 24 and 48hrs to quantify cell attachment and growth on the hydrogels. All gel types allowed cell attachment and growth with cell counts of 6333±1100 (PEGDA-GRGDS), 4000±943 (PEGDA-GRGDS-HA) and 3000±157 (PEGDA-HA) after 48hrs. As PEGDA alone is non-adhesive to cells, this suggests that hydroxyapatite is promoting cell adhesion. The PEG-GRGDS-HA hydrogels were then cast in theta-shaped glass capillary tubes and the scaffolds were preloaded with primary tendon fibroblasts. After 4 days of incubation, sectioning and staining of the constructs showed DAPI and phalloidin staining primarily on the outside of the scaffolds, with isolated cells within the matrix. These studies suggest that the PEGDA-GRGDS-HA hydrogel may be a suitable scaffold for co-culture with an engineered muscle monolayer in the development of a muscle-machine interface to replicate the myotenindous junction in an in vitro model of skeletal muscle physiology.