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The effect of sterilization on transforming growth factor β isolated from demineralized human bone
Author(s) -
Puolakkainen P.A.,
Ranchalis J.E.,
Strong D.M.,
Twardzik D.R.
Publication year - 1993
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1046/j.1537-2995.1993.33893342752.x
Subject(s) - sterilization (economics) , irradiation , dentistry , bone morphogenetic protein , chemistry , andrology , medicine , biochemistry , physics , nuclear physics , monetary economics , economics , foreign exchange market , gene , foreign exchange
Growth factors have been identified as the primary cause of osteoinduction in bone healing. Transforming growth factor β (TGF‐β) has been shown to promote bone formation and is present in bone in high quantities. The aims of the present study were to isolate TGF‐β from human bone, demonstrate its biologic activity, and analyze the effects of conventional sterilization techniques on activity. Bone, obtained from femoral heads of five patients (mean age, 70 years) was ground, demineralized, and freeze‐dried, and samples from each patient were divided into three groups: no treatment, sterilization with 1.60 to 1.94 Mrad of 60 Co irradiation, and sterilization with ethylene oxide (ETO). Carrier‐free recombinant TGF‐β control was also treated and was totally inactivated by ETO but not by irradiation (p < 0.01). TGF‐β activity in demineralized bone was not significantly diminished (p > 0.1) by either sterilization procedure, and substantial amounts of active TGF‐β were recovered in all bone samples: 1.04 ± 0.77 ng per mg of protein in irradiated samples, 0.67 ± 0.26 ng per mg in ETO‐treated samples, and 1.04 ± 0.33 in untreated samples, respectively (mean ± SD). Although a recent report demonstrated that the osteoinductive activity of bone morphogenetic protein in bone powder is diminished considerably by ETO and by 2.5 Mrad of irradiation sterilization of bone powder, these data demonstrate that TGF‐β activity, with its osteoinductive properties, was not destroyed in more coarsely ground, demineralized bone by ETO or by lower doses of irradiation. These findings support the use of human bone allografts in clinical instances involving impaired bone formation.