Early Osteogenic Marker Expression in hMSCs Cultured onto Acid Etching-Derived Micro- and Nanotopography 3D-Printed Titanium Surfaces.

Polyetheretherketone (PEEK) titanium composite (PTC) is a novel interbody fusion device that combines a PEEK core with titanium alloy (Ti6Al4V) endplates. The present study aimed to investigate the in vitro biological reactivity of human bone-marrow-derived mesenchymal stem cells (hBM-MSCs) to micro- and nanotopographies produced by an acid-etching process on the surface of 3D-printed PTC endplates. Optical profilometer and scanning electron microscopy were used to assess the surface roughness and identify the nano-features of etched or unetched PTC endplates, respectively. The viability, morphology and the expression of specific osteogenic markers were examined after 7 days of culture in the seeded cells. Haralick texture analysis was carried out on the unseeded endplates to correlate surface texture features to the biological data. The acid-etching process modified the surface roughness of the 3D-printed PTC endplates, creating micro- and nano-scale structures that significantly contributed to sustaining the viability of hBM-MSCs and triggering the expression of early osteogenic markers, such as alkaline phosphatase activity and bone-ECM protein production. Finally, the topography of 3D-printed PTC endplates influenced Haralick's features, which in turn correlated with the expression of two osteogenic markers, osteopontin and osteocalcin. Overall, these data demonstrate that the acid-etching process of PTC endplates created a favourable environment for osteogenic differentiation of hBM-MSCs and may potentially have clinical benefit.

Hybrid approach in sacral sore management with maggot debridement therapy and flap reconstruction.

Sacral sore is a common problem in patients with spinal cord injury. It leads to prolonged hospitalization and recurrent infections which might require repeated surgery to treat. Flap reconstruction allows soft tissue coverage of sacral sore under the premise of infection-free wound base. Maggot debridement therapy (MDT) has been described as an alternative non-surgical management as opposed to the traditional surgical debridement in case of infected sore, reducing number of surgeries under anaesthesia. However, MDT and surgery are not mutually exclusive. In this article we describe a hybrid approach combining MDT and flap reconstruction with multi-disciplinary effort in management of sacral sore, which accelerates wound healing and prevents morbidities, while lowering the risks associated with repeated surgical debridement at the same time.