Improved methods are provided for the recombinant synthesis of collagen, particularly collagen VII, in host cell, and for therapeutic delivery of the same. The recombinant collagen is produced in a host cell that has increased levels of prolyl-4-hydroxylase, relative to basal cell levels. The collagen produced by the methods of the invention has increased numbers of modified proline residues, relative to a recombinant collagen produced in a host cell having basal levels of prolyl-4-hydroxylase. The increased proline modification provides for a collagen having increased stability, including increased in vivo stability.