Hyaluronan-based heparin-incorporated hydrogels for generation of axially vascularized bioartificial bone tissues: in vitro and in vivo evaluation in a PLDLLA-TCP-PCL-composite system

Smart matrices are required in bone tissueengineered grafts that provide an optimal environment for cells and retain osteo-inductive factors for sustained biological activity. We hypothesized that a slow-degrading heparin-incorporated hyaluronan (HA) hydrogel can preserve BMP-2; while an arterio–venous (A–V) loop can support axial vascularization to provide nutrition for a bioartificial bone graft. HA was evaluated for osteoblast growth and BMP-2 release. Porous PLDLLA–TCP–PCL scaffolds were produced by rapid prototyping technology and applied in vivo along with HA-hydrogel, loaded with either primary osteoblasts or BMP-2. A microsurgically created A–V loop was placed around the scaffold, encased in an isolation chamber in Lewis rats. HA-hydrogel supported growth of osteoblasts over 8 weeks and allowed sustained release of BMP-2 over 35 days. The A–V loop provided an angiogenic stimulus with the formation of vascularized tissue in the scaffolds. Bone-specific genes were detected by real time RT-PCR after 8 weeks. However, no significant amount of bone was observed histologically. The heterotopic isolation chamber in combination with absent biomechanical stimulation might explain the insufficient bone formation despite adequate expression of bone-related genes. Optimization of the interplay of osteogenic cells and osteo-inductive factors might eventually generate sufficient amounts of axially vascularized bone grafts for reconstructive surgery

How framing bias impacts preferences for innovation in bone tissue engineering

It is currently unknown if surgeons and biomaterial scientists &amp;or tissue engineers (BS&amp;orTE) process and evaluate information in similar or different (un)biased ways. For the gold standard of surgery to move “from bench to bedside”, there must naturally be synergies between these key stakeholders’ perspectives. Because only a small number of biomaterials &amp; tissue engineering innovations have been translated into the clinic today, we hypothesised this lack of translation is rooted in the psychology of surgeons and BS&amp;orTE. Presently, both clinicians and researchers doubt the compatibility of surgery and research in their daily routines. This has led to the use of a metaphorical expression "squaring of the circle," which implies an unsolvable challenge. As bone tissue engineering belongs to the top 5 research areas in tissue engineering we choose the field of bone defect treatment options for our bias study. Our study uses an online survey instrument for data capture: incorporating a behavioural economics cognitive framing experiment methodology. Our study sample consisted of surgeons (n=208) and BS&amp;orTE (n=59). And we employed a convenience sampling method, with participants (conference attendants) being approached both in person and via email - 22 October 2022-13 March 2023. We find no distinct positive-negative cognitive framing differences by occupation. That is, any framing bias present in this surgical decision-making setting does not appear to differ significantly between surgeon and BS&amp;orTE specialisation. When we explored within group differences by frames, we see statistically significant (p<0.05) results for surgeons in the positive frame ranking autologous bone graft transplantation lower compared to surgeons in the negative frame. Further, surgeons in the positive frame rank Ilizarov bone transport method higher compared to surgeons in the negative frame (p<0.05)