In vivo characterization of 3D-printed polycaprolactone-hydroxyapatite scaffolds with Voronoi design to advance the concept of scaffold-guided bone regeneration

Abstract

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In vivo study to assess fat embolism resulting from the Reamer-Irrigator-Aspirator 2 system compared to a novel aspirator-based concept for intramedullary bone graft harvesting

“…To achieve effective BG harvesting, the RIA system applies continuous irrigation and suction during IM reaming of long bones. Recently, a novel harvesting concept aimed at improving the BG collection without the potential washout effect of osteogenic factors in the graft material associated with the RIA system’s irrigation fluid was successfully tested [ 3 , 4 ]. This novel concept includes the option of initially aspirating the bone marrow (BM) using a novel aspirator prototype (aspirator, A), followed by sequential reaming using standard reamers and collecting BG with the novel aspirator prototype (reamer + aspirator, R + A), which has been shown to have the capacity to preserve the BG’s osteoimmune microenvironment associated with high osteogenic potential (A + R + A concept) [ 3 ].…”

An innovative intramedullary bone graft harvesting concept as a fundamental component of scaffold-guided bone regeneration: A preclinical in vivo validation

“…Fig. 1 ) was found to exhibit suitable and slow in vitro degradation behaviour (<1 % mass loss within 6 months) and favourable in vivo biocompatibility when combined with bone grafts (BGs), as typically used in clinical SGBR settings [ 5 ].…”

“…In the clinic, for the reconstruction of large bone defects within the context of SGBR, a BG is usually harvested from the intramedullary canal of long bones using the Reamer-Irrigator-Aspirator (RIA) 2 system (Synthes) [ 20 , 21 ]. A novel harvesting concept, described as the aspirator + reaming-aspiration concept (“ARA” concept), has recently been developed for harvesting of intramedullary BG [ 5 , 21 ]. The ARA concept allows bone marrow to be harvested first, followed by the sequential reaming and iterative use of a new aspirator device to harvest intramedullary BG [ 21 ].…”

“…Another disadvantage of the RIA 2 system BG is that bone marrow and bone chips are harvested at the same time and therefore the ratio of bone marrow to bone chips in the harvest cannot be controlled [ 23 ]. This leads to large variations in graft composition between patients, which is important to consider because relevant proportions of bone chips in BGs are necessary to achieve sufficient osteogenic capacity for bone defect regeneration [ 5 , 21 ], especially as the osteogenic capacity of bone marrow is strongly dependent on age, body fat content, and disease state [ [24] , [25] , [26] ].…”

“…However, this successful in vitro study requires in vivo preclinical confirmation before moving to large animal studies and clinical trials [ 27 , 28 ]. Hence, we determined in this study the potential of the new ARA concept by evaluating the in vivo osteogenic capacity of the BG harvest, loaded in a 3D-printed, Voronoi scaffold made of mPCL-HA, in a rat model of ectopic bone formation (EBF) [ 5 ]. Considering the use of the scaffold biomaterials represents an elementary part of the SGBR concept, hence we first undertook these characterizations.…”