Relevance of fiber integrated gelatin-nanohydroxyapatite composite scaffold for bone tissue regeneration.

Porous nanohydroxyapatite (nanoHA) is a promising bone substitute, but it is brittle, which limits its utility for load bearing applications. To address this issue, herein, biodegradable electrospun microfibrous sheets of poly(L-lactic acid)-(PLLA)-polyvinyl alcohol (PVA) were incorporated into a gelatin-nanoHA matrix which was investigated for its mechanical properties, the physical integration of the fibers with the matrix, cell infiltration, osteogenic differentiation and bone regeneration. The inclusion of sacrificial fibers like PVA along with PLLA and leaching resulted in improved cellular infiltration towards the center of the scaffold. Furthermore, the treatment of PLLA fibers with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide enhanced their hydrophilicity, ensuring firm anchorage between the fibers and the gelatin-HA matrix. The incorporation of PLLA microfibers within the gelatin-nanoHA matrix reduced the brittleness of the scaffolds, the effect being proportional to the number of layers of fibrous sheets in the matrix. The proliferation and osteogenic differentiation of human adipose-derived mesenchymal stem cells was augmented on the fibrous scaffolds in comparison to those scaffolds devoid of fibers. Finally, the scaffold could promote cell infiltration, together with bone regeneration, upon implantation in a rabbit femoral cortical defect within 4 weeks. The bone regeneration potential was significantly higher when compared to commercially available HA (Surgiwear™). Thus, this biomimetic, porous, 3D composite scaffold could be offered as a promising candidate for bone regeneration in orthopedics.

Defect components and reconstructive options in composite orbitomaxillary defects with orbital exenteration.

PURPOSE: The conventional way of reconstructing an orbital exenteration defect associated with a maxillectomy is to cover it with a soft tissue free flap and camouflage it with a spectacle-mounted orbital prosthesis. Also, there are some reports on the use of bone flaps. The objective of this study was to review the reconstructive options for a defect resulting after orbital exenteration and maxillectomy. MATERIALS AND METHODS: This study concerns a retrospective case series of 20 patients. Electronic medical records, including clinical details, operative notes, and follow-up data, were analyzed. Defects were analyzed for their reconstructive components. The reconstructive methods used were studied by the types of flap used, bony versus soft tissue types of reconstruction, and the prosthetic method used to rehabilitate the eye. Outcomes were analyzed for flap success rate. Descriptive methods for data analysis were used. RESULTS: Fourteen patients underwent a soft tissue reconstruction alone and 6 underwent bony reconstruction. The free rectus abdominis was the commonest soft tissue flap used. This article presents the outcome of reconstruction in such patients and the utility of individual flaps for their ability to replace different components of the defect. CONCLUSIONS: Ideal reconstruction should address all individual defect components of facial contour, orbital, palatal, skull base, and skin defects. The free rectus abdominis flap remains the common choice. When a composite socket reconstruction is to be achieved, the innovative free tensor fascia lata flap with the iliac crest bone and internal oblique muscle is an option.