Evaluation of Material Permeability of Type I Collagen Hydrogel / 中国医疗器械杂志

OBJECTIVES@#To establish an experimental method for evaluating material permeability of type I collagen hydrogels.@*METHODS@#Using BSA-FITC as an indicator, by combining BSA-FITC with PBS they were used as permeability media, and using transwell load hydrogen sample to detect BSA-FITC transparent rate.@*RESULTS@#In the concentration range of 100 μg·mL~0.781 μg·mL, the standard curve ≥ 0.99, Lower Limit of Quantity (LLOQ) is 3.125 μg·mL, RSD <5%, detection recovery rate is in the range of 80%~120%.@*CONCLUSIONS@#In this study, we established an experimental method for evaluating material permeability of hydrogel. The BSA-FITC transparent rate of type I collagen hydrogel was 100% at 28 h.

Assessment Method of Remnant α-1, 3-galactosyle Epitopes in Animal Tissue-derived Biomaterials / 生物医学工程学杂志

The aim of this study was to establish an assessment method for determining α-Gal (α-1, 3-galactosyle) epitopes contained in animal tissue or animal tissue-derived biological materials with ELISA inhibition assay. Firstly, a 96 well plate was coated with Gal α-1, 3-Gal/bovine serum albumin (BSA) as a solid phase antigen and meanwhile, the anti-α-Gal M86 was used to react with α-Gal antigens which contained in the test materials. Then, the residual antibodies (M86) in the supernatant of M86-Gal reaction mixture were measured using ELISA inhibition assay by the α-Gal coating plate. The inhibition curve of the ELISA inhibition assay, the R2 = 0.999, was well established. Checking using both α-Gal positive materials (rat liver tissues) and α-Gal negative materials (human placenta tissues) showed a good sensitivity and specificity. Based on the presently established method, the α-Gal expression profile of rat tissues, decellular animal tissue-derived biological materials and porcine dermal before and after decellular treatment were determined. The M86 ELISA inhibition assay method, which can quantitatively determine the α-Gal antigens contained in animal tissues or animal tissue-derived biomaterials, was refined. This M86 specific antibody based-ELISA inhibition assay established in the present study has good sensitivity and specificity, and could be a useful method for determining remnant α-1, 3Gal antigens in animal tissue-derived biomaterials.

Overview on the market, supervision and standardization of nanomaterial-contained medical devices / 中国医疗器械杂志

In this paper, industry development and market tendency, supervision and standardization of nanomaterial-contained medical devices are overviewed comprehensively based on a large number of reference data including national and international information. Furthermore, the consideration about standardization of biological evaluation for nanomaterial-contained medical devices is discussed by combined some works performed in our laboratory.

Quantification of residues DNA in animal-derived biological scaffold materials / 生物医学工程学杂志

Quantification of residual DNA in animal-derived biological scaffold materials is one of technical specifications for evaluating decellularization process and immunotoxicity risk. Up to now, there have been no standard methods available for quantification of residues DNA in animal-derived biological scaffold materials. In this study, a three-step method, including proteinase K digestion, DNA purification and determination of DNA using fluorescence assay, was designed for residual DNA quantification. A parallel recovery experiment of standard DNA using the same protocol to test article determination was used for adjusting final results of residuul DNA amount. DNA purification based on magnetic beads enabled the experiments to get high accuracy and repeatability. The validation experiment showed that the three-step method had high sensitivity up to 6.25ng of DNA per sample with good linearity (recovery curve R2 > 0.99) in the concentration range of 3. 125-100ng, and 25-400ng per sample. This method is useful for determining micro or trace amount DNA remained in the biomaterials.