Poly-L/D-lactide (PLDLA) 96/4 fibrous implants have been introduced to engineer functional fibrous constructions in situ. The current study was undertaken to evaluate the guidance of the fibrous tissue formation and the tissue reaction of porous PLDLA 96/4 scaffolds implanted in subcutaneous tissue. Three various PLDLA 96/4 knitted-mesh scaffolds (Loose, Ordinary, and Dense) were implanted subcutaneously in 32 rats, and followed-up from 3 days until 48 weeks postsurgery. Histological examination showed that PLDLA 96/4 scaffolds provided a structurally supporting element for 48 weeks. They were filled with fibrous tissue by 3 weeks. During the follow-up, loose connective tissue was organized into dense connective tissue with thick collagen bundles. At 48 weeks, no statistically significant difference was found in the amount of loose or dense connective tissue between the scaffold groups of various porosities, although the tendency for higher amounts of loose connective tissue was seen in the Loose type scaffolds. PLDLA filament diameters were 121 μm at 2 weeks, 119 μm at 24 weeks and 116 μm at 48 weeks (P = 0.03 between 2 and 48 weeks). Porous PLDLA scaffold induced fibrous tissue formation in situ. This can be exploited in engineering fibrous tissue constructs in vivo for tissue support or replacement purposes.
From the *Department of Ophthalmology, Oulu University Hospital, PO Box 22, FIN-90029 Oulu, Finland; †Department of Pathology, Oulu University Hospital, PO Box 50, FIN-90029 Oulu, Finland; ‡Division of Hand Surgery, Department of Surgery, Oulu University Hospital, PO Box 20, FIN-90029 Oulu, Finland; §Institute of Biomaterials, Tampere University of Technology, PO Box 589, FIN-33101 Tampere, Finland; ∥Biomedicum Helsinki, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki, Finland; and #Division of Plastic Surgery, Department of Surgery, Oulu University Hospital, PO Box 20, FIN-90029 Oulu, Finland.
Address correspondence and reprint requests to Prof. Nureddin Ashammakhi, FRCSEd, Institute of Biomaterials, Tampere University of Technology, PO Box 589 (Hermiankatu 12 B), FIN-33101 Tampere, Finland; E-mail: firstname.lastname@example.org
Supported by the Biomaterials and Tissue Engineering Graduate School, Technology Development Center in Finland (TEKES 40056/04), the European Commission (Project QLRT-2000-00487) and the Academy of Finland (Project 5205427). This study is within the scope of the EU Network of Excellence "EXPERTISSUES".