Purpose: Currently, a number of bioresorbable and biodegradable membranes used for guided bone regeneration lead to incomplete tissue regeneration. Poor mechanical properties, short degradation time, and the lack of integrated biologic components result in the inability to create and maintain an appropriate environment and to actively support tissue remodeling. In the present study, the osteogenic potential of human calvarial periosteal cells in combination with ultrathin polycaprolactone (pc2) membranes of a slow biodegradation rate was investigated. Materials and Methods: In vitro and in vivo analyses of the tissue-engineered constructs were conducted using imaging techniques, immunohistochemistry, and histology. Two types of membranes were investigated. Group 1 consisted of a plain membrane, and in group 2 membranes were treated with sodium hydroxide. Results: In vitro results showed that osteoblast-like cells attached and proliferated on the membranes with the formation of extracellular matrix. Sodium hydroxide-treated membranes showed enhanced cell attachment and proliferation kinetics, resulting in a dense cellular layer after 2 weeks in culture. In vivo mineralized tissue formation in association with vascularization was observed. Extracellular matrix calcification with nodule formation was detected via histology as well as scanning electron microscopy. Discussion: PCL membranes support the attachment, growth, and osteogenic differentiation of human primary osteoblast-like cells. Sodium hydroxide-treated membranes demonstrated increased cell attachment resulting from increased hydrophilicity. Conclusion: These findings have potential application in the development of a new generation of osteoconductive membranes. Schlagwörter: guided bone regeneration, periosteal cells, polycaprolactone membrane, tissue engineering