Statement of Purpose: Although there have been significant advances within tissue engineering, translation has proven difficult with ongoing challenges regenerating complex tissues with a heterogeneous structure and multiple cell types. In particular, the transitional or interfacial tissue between adjacent tissues has complex gradients of structure, cell type, and chemical composition. For example, the tendon to bone interfacial tissue gradually transitions from highly aligned fibrous tissue to calcified bone . For transitions between musculoskeletal tissues (e.g., ligament or tendon to bone, muscle to tendon, cartilage to bone, etc.), the interfacial region is critical for transferring mechanical load from one tissue type to another. Developing new biomaterial fabrication strategies capable of mimicking the heterogeneous nature of interfacial tissues, as well as other complex tissues, is vital for spatially controlling cellular behavior and resulting in functional interfacial tissue regeneration. Towards this aim, we have developed an innovative magnetically-assisted electrospinning technique to selectively and precisely control gradients in fiber alignment.