Development of an improved bone washing and demineralisation process to produce large demineralised human cancellous bone sponges

Abstract

Shaped demineralised bone matrices (DBM) made from cancellous bone have important uses in orthopaedic and dental procedures, where the properties of the material allow its insertion into confined defects, therefore acting as a void filler and scaffold onto which new bone can form. The sponges are often small in size, <1.0 cm(3). In this study, we report on an improved bone washing and demineralisation process that allows production of larger DBM sponges (3.375 or 8.0 cm(3)) from deceased donor bone. These sponges were taken through a series of warm water washes, some with sonication, centrifugation, 100 % ethanol and two decontamination chemical washes and optimally demineralised using 0.5 N hydrochloric acid under vacuum. Demineralisation was confirmed by quantitative measurement of calcium and qualitatively by compression. Protein and DNA removal was also determined. The DBM sponges were freeze dried before terminal sterilisation with a target dose of 25 kGy gamma irradiation whilst frozen. Samples of the sponges were examined histologically for calcium, collagen and the presence of cells. The data indicated lack of cells, absence of bone marrow and a maximum of 1.5 % residual calcium.

Time-Dependent Demineralization of Tilapia (Oreochromis niloticus) Bones Using Hydrochloric Acid for Extracellular Matrix Extraction

“…The residual calcium content was found to be 1.10 ± 0.12% after 1 h and <0.1% after 6 h of demineralization. Interestingly, allograft bone, which retained 2% of its mineral content after demineralization, exhibited the most significant osteoinductive potential [ 36 , 37 ]. Moreover, understanding the kinetics of the demineralization process is crucial in developing an efficient and effective method for bone demineralization.…”

Polyurethane scaffolds seeded with CD34+ cells maintain early stem cells whilst also facilitating prolonged egress of haematopoietic progenitors

“…These consisted of cancellous bone harvested from the knee joint of donors and cut using a saggital saw to the approximate size of polyurethane scaffolds. Scaffolds were decellularised to a level of 99.92% as previously described58, and gamma irradiated.…”

An Extrudable Partially Demineralized Allogeneic Bone Paste Exhibits a Similar Bone Healing Capacity as the “Gold Standard” Bone Graft

“…In light of this, improvement of the demineralization (HCl baths), sterilization (gamma rays, autoclaving), and cleaning processes (NaOH baths, supercritical CO 2, sonication) of the bone tissues (Froum et al, 2002;Wood and Mealey, 2012;Eagle et al, 2015;Chadwick et al, 2016;Whetman and Mealey, 2016;Narotzky et al, 2020) are important to limit the variable outcomes in terms of bone healing that are largely due to the very different procedures and associated with alteration of the bone tissue (Rasch et al, 2019). In order to combine the radio-opacity of mineralized BGs and the regenerative properties of demineralized BGs, partially demineralized BGs have been developed in the past decades in block forms (Hallfeldt et al, 1995).…”