Recent baby formula milk powder contamination incidents have shown that the classic markers or standards in milk quality control are insufficient in identifying "manipulated" poor-quality milk. In the present study, we demonstrated for the first time that cow milk contains large amounts of microRNAs (miRNAs) and that the unique expression profile of milk-specific miRNAs can serve as a novel indicator and possible new standard for the quality control of raw milk and milk-related commercial products, such as fluid milk and powdered formula milk. First, using Solexa sequencing, we systematically screened miRNA expression in raw milk and identified a total of 245 miRNAs in raw milk. Unlike other classic biomarkers whose expression levels are nearly identical at different periods of lactation, individual miRNAs can be significantly altered during lactation process, implicating that miRNAs may be a more accurate indicator to reflect the quality alteration of milk. Second, using TaqMan probe-based miRNA quantitative RT-PCR, we further identified seven miRNAs that have a relatively consistent expression throughout the lactation process, and more importantly, the expression profile of these seven milk-specific miRNAs can serve as an ideal biomarker for discriminating poor-quality or "manipulated" milk from pure raw milk, as well as for the quality control of commercial milk products, such as fluid milk and powdered formula milk. Together, our findings provide a basis for understanding the physiological role of milk miRNAs and a new potential standard for determining the quality of raw milk or milk-related commercial products.

Acellular matrix materials have been widely used to repair various tissues and organs. According to the plastic principle, when a part of the body is lost, it should be replaced with a similar material. Therefore, the use of a homologous organ-specific acellular vaginal tissue in vagina reconstruction repair surgery may show good results. However, the acellular vagina matrix (AVM) form large vertebrates is difficult to isolate. In this study, we described a multistep method to prepare porcine AVM and evaluated the efficacy of acellularization. We also investigated the biomechanical properties, biological activity elements, and biocompatibility of the porcine AVM. We then used this material to reconstruct a rat vagina and performed further morphologic and functional analyses. Small intestinal submucosa (SIS), which is a commonly used acellular matrix material, was used in a control group. Histological examination, DNA content analysis, and agarose gel electrophoresis revealed that the decellularization procedure was effective. The AVM had acceptable biomechanical properties and sufficient growth factor production (VEGF, FGF, TGF-β1, and PDGF-BB) compared with that of the SIS. Subcutaneous transplantation in rats showed that the AVM had good biocompatibility. The tissue-engineered vagina using the AVM more resembled normal-appearing tissue than did that using SIS following morphologic and functional analyses. The AVM has great potential for application in vaginal reconstructive surgery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1949-1959, 2017.

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