DNA constructs are prepared which operably link human interferon genes, selective, eukaryotic marker genes, and promoter and expression control sequences for the expression of human interferon in Chinese hamster ovary (CHO) cells or progeny thereof. The human recombinant interferon so produced contains glycans which are a subset of the population of glycans which are contained in the native randomly dispersed polytetrafluoroethylene fibers, or mixtures of cellulose acetate and cellulose nitrate fibers, or polyvinylidine difluoride fibers and the material has a pore size such that desired biological nutrients are permitted passage through the implant structure and unwanted biological cells are precluded from passage therethrough, The layers of perforated metallic sheet material and microporous membrane material are maintained together to form the composite structure by a biocompatible adhesive, heat fusion of the fibers of the membrane material or mechanical fasteners interacting between the layers. The implant structure is particularly applicable to use for the guided regeneration and enlargement of bone tissue at surgical sites.