Bae Hyun W, Zhao Li, Kanim Linda E A, Wong Pamela, Delamarter Rick B, Dawson Edgar G
Spine Research Foundation, Spine Institute at Saint John's Health Center, Santa Monica, CA 90404, USA.
Spine (Phila Pa 1976). 2006 May 20;31(12):1299-306; discussion 1307-8. doi: 10.1097/01.brs.0000218581.92992.b7.
Enzyme-linked immunosorbent assay was used to detect bone morphogenetic proteins (BMPs) 2, 4, and 7 in 9 commercially available ("off the shelf") demineralized bone matrix (DBM) product formulations using 3 different manufacturer's production lots of each DBM formulation.
To evaluate and compare the quantity of BMPs among several different DBM formulations (inter-product variability), as well as examine the variability of these proteins in different production lots within the same DBM formulation (intra-product variability).
DBMs are commonly used to augment available bone graft in spinal fusion procedures. Surgeons are presented with an ever-increasing variety of commercially available human DBMs from which to choose. Yet, there is limited information on a specific DBM product's osteoinductive efficacy, potency, and constancy.
There were protein extracts from each DBM sample separately dialyzed 4 times against distilled water at 4 degrees C for 48 hours. The amount of BMP-2, BMP-4, and BMP-7 was determined using enzyme-linked immunosorbent assay. RESULTS.: The concentrations of detected BMP-2 and BMP-7 were low for all DBM formulations, only nanograms of BMP were extracted from each gram of DBM (20.2-120.6 ng BMP-2/g DBM product; 54.2-226.8 ng BMP-7/g DBM). The variability of BMP concentrations among different lots of the same DBM formulation, intra-product variability, was higher than the variability of concentrations among different DBM formulations, inter-product variability (coefficient of variation range BMP-2 [16.34% to 76.01%], P < 0.01; BMP-7 [3.71% to 82.08%], P < 0.001). BMP-4 was undetectable.
The relative quantities of BMPs in DBMs are low, in the order of 1 x 10(-9) g of BMP/g of DBM. There is higher variability in concentration of BMPs among 3 different lots of the same DBM formulation than among different DBM formulations. This variability questions DBM products' reliability and, possibly, efficacy in providing consistent osteoinduction.
采用酶联免疫吸附测定法，使用9种市售（“现货供应”）脱矿骨基质（DBM）产品配方，每种DBM配方使用3个不同制造商的生产批次，检测骨形态发生蛋白（BMP）2、4和7。
评估和比较几种不同DBM配方中BMP的含量（产品间变异性），并检查同一DBM配方不同生产批次中这些蛋白质的变异性（产品内变异性）。
DBM常用于脊柱融合手术中增加可用骨移植材料。外科医生可选择的市售人DBM种类日益增多。然而，关于特定DBM产品的骨诱导效力、效能和稳定性的信息有限。
将每个DBM样品的蛋白质提取物在4℃下用蒸馏水分别透析4次，每次48小时。使用酶联免疫吸附测定法测定BMP-2、BMP-4和BMP-7的含量。结果：所有DBM配方中检测到的BMP-2和BMP-7浓度都很低，每克DBM中仅提取到纳克级别的BMP（20.2 - 120.6 ng BMP-2/g DBM产品；54.2 - 226.8 ng BMP-7/g DBM）。同一DBM配方不同批次间BMP浓度的变异性，即产品内变异性，高于不同DBM配方间浓度的变异性，即产品间变异性（变异系数范围BMP-2 [16.34%至76.01%]，P < 0.01；BMP-7 [3.71%至82.08%]，P < 0.001）。未检测到BMP-4。
DBM中BMP的相对含量较低，约为1×10⁻⁹ g BMP/g DBM。同一DBM配方的3个不同批次间BMP浓度的变异性高于不同DBM配方间的变异性。这种变异性对DBM产品的可靠性以及可能在提供一致骨诱导方面的效能提出了质疑。
