Department of Urology, S. Giovanni Bosco Hospital, Turin, Italy.
Drug Test Anal. 2009 Sep;1(9-10):447-54. doi: 10.1002/dta.96.
Several clinical-grade immunoassays exist for the specific measurement of hGH or its isoforms in blood but there is an urgent need to apply these same reliable assays to the measurement of hGH in urine as a preferred 'non-invasive' biofluid. Unfortunately, conventional hGH immunoassays cannot attain the sensitivity required to detect the low concentrations of hGH in urine. The lowest limit of sensitivity for existing hGH immunoassays is >50 pg/mL, while the estimated concentration of urinary hGH is about 1 pg/m-50 times lower than the sensitivity threshold. We have created novel N-isopropylacrylamide (NIPAm)-based hydrogel nanoparticles functionalized with an affinity bait. When introduced into an analyte-containing solution, the nanoparticles can perform, in one step, (1) complete harvesting of all solution phase target analytes, (2) full protection of the captured analyte from degradation and (3) sequestration of the analyte, effectively increasing the analyte concentration up to a hundredfold. N-isopropylacrylamide nanoparticles functionalized with Cibacron Blue F3GA bait have been applied to raise the concentration of urinary hGH into the linear range of clinical grade immunoassays. This technology now provides an opportunity to evaluate the concentration of hGH in urine with high precision and accuracy.
有几种临床级别的免疫测定法可用于特异性测量血液中的 hGH 或其同工型，但迫切需要将这些相同的可靠测定法应用于尿液中 hGH 的测量，因为尿液是首选的“非侵入性”生物流体。不幸的是，常规的 hGH 免疫测定法无法达到检测尿液中低浓度 hGH 所需的灵敏度。现有的 hGH 免疫测定法的最低灵敏度限为>50pg/mL，而尿液中 hGH 的估计浓度约为 1pg/ml，比灵敏度阈值低 50 倍。我们已经开发了新型基于 N-异丙基丙烯酰胺（NIPAm）的水凝胶纳米颗粒，其功能化有亲和诱饵。当引入含有分析物的溶液中时，纳米颗粒可以一步完成以下操作：（1）完全收集所有溶液相目标分析物，（2）完全保护捕获的分析物免受降解，以及（3）隔离分析物，从而将分析物的浓度有效提高至 100 倍。用 Cibacron Blue F3GA 诱饵功能化的 N-异丙基丙烯酰胺纳米颗粒已被应用于提高尿液中 hGH 的浓度至临床级免疫测定法的线性范围。该技术现在为评估尿液中 hGH 的浓度提供了高精度和准确性的机会。
