The Preservation of Bone Cell Viability in a Human Femoral Head through a Perfusion Bioreactor

Abstract

Current methods for drug development and discovery involve pre-clinical analyses that are extremely expensive and time consuming. Animal models are not the best precedent to use, when comparing to human models as they are not synonymous with the human response, thus, alternative methods for drug development are needed. One of which could be the use of an ex vivo human organ where drugs could be tested and the effects of those drugs could be observed. Finding a viable human organ to use in these preliminary ex vivo studies is difficult due to the availability, cost, and viability. Bone tissue and marrow contain a plethora of both bone and stem cells, however, these cells need constant perfusion to be viable over a longer time range. Here we maintain bone cell sustainability in an ex vivo model, through the use of human femoral heads in a novel bioreactor. This bioreactor was designed to directly perfuse cell culture media (DMEM) through the vasculature of a femoral head, providing ideal nutrients and conditions required for maintaining organ viability. We show, for the first time, that cells within a femoral head can stay alive up to 12 h. Further development could be used to determine the effects of drugs on a human organ system and could aid in the understanding of the progression of bone diseases and pathologies.

A Method for the Evaluation of Early Osseointegration of Implant Materials Ex Vivo: Human Bone Organ Model

“…Mechanical loading, static or cyclic, is important to maintain bone response [ 16 , 17 ]. Increased cell viability in bioreactor using medium perfusion through vasculature of femoral head was reported [ 18 ]. Some other models attempt to mimic bone remodeling in vitro [ 26 ], evaluate the viability of bone cells within 3D scaffolds [ 27 , 28 , 29 ] or used humanized mice bone model [ 30 , 31 ].…”

“…The limitation of such organ models is the weak repopulation with the very few cells and, therefore, a need for additional seeding of osteoblasts, cultured in vitro [ 17 ]. The other limitation of reported ex vivo organ models is that bone tissue does not contain any vasculature and contain only the trabecular part of the bone [ 14 , 17 , 18 ]. Finally, up to now no studies reported an analysis of the outgrowth of bone cells onto implant surface using organ models.…”

Ex vivo Bone Models and Their Potential in Preclinical Evaluation

“…Trabecular bone cores (Ø = 6-20 mm, height = 4-7 mm), obtained from femoral heads or tibia plateaus removed during replacement surgeries, demonstrated successful preservation of viability ex vivo, when cultured up to 4 weeks [14, 35, 43, 44•, 46, 80, 86, 87]. Notably, a recent study reported that an entire human femoral head could be kept viable for 12 h when culture medium was perfused through the remaining vasculature [24].…”

Bioreactor analyses of tissue ingrowth, ongrowth and remodelling around implants: An alternative to live animal testing

“…But even if not considered replacement, the approach still contributes greatly to reduction and refinement by enabling multiple samples to be obtained for each animal sacrificed, reuse of material that might otherwise be wasted, and by refining the protocol to eliminate all experimentation on the animal while it is living. There is even scope to use human tissue by utilising waste from routine surgical procedures, such as femoral heads resected during hip arthroplasty ( Swarup et al, 2018 ; Styczynska-Soczka et al, 2021 ).…”

“…Early research has demonstrated that ex vivo bone can grow and adapt to mechanical loading in a bioreactor setup ( Jones et al, 2003 ; Davies et al, 2006 ; David et al, 2008 ; Vivanco et al, 2013 ; Birmingham et al, 2015 ; Birmingham et al, 2016 ). More recent research has demonstrated material and cell transfer to an implant surface ( Dua et al, 2021 ; Zankovic et al, 2021 ) and that is possible to maintain viability in samples as large as human femoral heads ( Swarup et al, 2018 ; Styczynska-Soczka et al, 2021 ), but it is still not clear if the ex vivo bone can be used to explore the early stages of implant bone ingrowth into porous implants. Nor is it clear if the full remodelling pathways of bone are active.…”