Simple and rapid identification of beef within 30 min using a new food nucleic acid release agent combined with direct-fast qPCR.

Simple and rapid molecular detection technologies for authenticating animal species are urgently needed for food safety and authenticity. This study established a new direct-fast quantitative polymerase chain reaction (qPCR) detection technology for beef to achieve rapid and on-site nucleic acid detection in food. This technology can complete nucleic acid extraction in 4 min using a new type of food nucleic acid-releasing agent, followed by direct amplification of the DNA sample by fast qPCR in 25 min. The results indicated that direct-fast qPCR can specifically identify beef and can also identify 0.00001% of beef components in artificially simulated meat mixtures, with a detection precision variation coefficient of <4%. This method can be used to effectively identify beef in different food samples. As a simple, fast, and accurate molecular detection technology for beef, this method may provide a new tool for the on-site detection of beef components in food.

Rapid Differential Detection of Wild-Type Classical Swine Fever Virus and Hog Cholera Lapinized Virus Vaccines by TaqMan MGB-Based Dual One-Step Real-Time RT-PCR.

To establish a rapid real-time RT-PCR method for differentiating wild-type classical swine fever virus (CSFV) strains from vaccine strains (HCLV), we designed a universal primer targeting the NS3 gene to detect wild-type CSFV strains and vaccine strains simultaneously, and two TaqMan-MGB probes were designed to differentiate between wild-type and vaccine strains. After optimizing the RT-qPCR conditions, a rapid dual TaqMan-MGB RT-qPCR method for the detection and identification of CSFV and HCLV was developed. The results showed that method could specifically detect CSFV and HCLV with no cross-reactivity with other swine pathogens. The analytic sensitivity for the NS3 gene of CSFV and HCLV were 1.67 × 101 copies/µL, respectively. For precision testing, the repeatability and reproducibility of the test was less than 2%. This method was successfully used for the rapid detection of 193 biological samples collected from CSFV-vaccinated pigs. This fast and accurate detection technology can be used for the detection of CSFV and is suitable for differentiating between wild-type CSFV strains and vaccine strains.

Dual-Nozzle 3D Printed Nano-Hydroxyapatite Scaffold Loaded with Vancomycin Sustained-Release Microspheres for Enhancing Bone Regeneration.

Background: Successful treatment of infectious bone defect remains a major challenge in the orthopaedic field. At present, the conventional treatment for infectious bone defects is surgical debridement and long-term systemic antibiotic use. It is necessary to develop a new strategy to achieve effective bone regeneration and local anti-infection for infectious bone defects. Methods: Firstly, vancomycin / poly (lactic acid-glycolic acid) sustained release microspheres (VAN/PLGA-MS) were prepared. Then, through the dual-nozzle 3D printing technology, VAN/PLGA-MS was uniformly loaded into the pores of nano-hydroxyapatite (n-HA) and polylactic acid (PLA) scaffolds printed in a certain proportion, and a composite scaffold (VAN/MS-PLA/n-HA) was designed, which can not only promote bone repair but also resist local infection. Finally, the performance of the composite scaffold was evaluated by in vivo and in vitro biological evaluation. Results: The in vitro release test of microspheres showed that the release of VAN/PLGA-MS was relatively stable from the second day, and the average daily release concentration was about 15.75 µg/mL, which was higher than the minimum concentration specified in the guidelines. The bacteriostatic test in vitro showed that VAN/PLGA-MS had obvious inhibitory effect on Staphylococcus aureus ATCC-29213. Biological evaluation of VAN/MS-PLA/n-HA scaffolds in vitro showed that it can promote the proliferation of adipose stem cells. In vivo biological evaluation showed that VAN/MS-PLA/n-HA scaffold could significantly promote bone regeneration. Conclusion: Our research shows that VAN/MS-PLA/n-HA scaffolds have satisfying biomechanical properties, effectively inhibit the growth of Staphylococcus aureus, with good biocompatibility, and effectiveness on repairing bone defects. The VAN/MS-PLA/n-HA scaffold provide the clinic with an application prospect in bone tissue engineering.

The Thermosensitive Injectable Celecoxib-Loaded Chitosan Hydrogel for Repairing Postoperative Intervertebral Disc Defect.

Percutaneous endoscopic lumbar discectomy has been widely used in clinical practice for lumbar spine diseases. But the postoperative disc re-herniation and inflammation are the main reason for pain recurrence after surgery. The postoperative local defect of the intervertebral disc will lead to the instability of the spine, further aggravating the process of intervertebral disc degeneration. In this work, we successfully synthesized the thermosensitive injectable celecoxib-loaded chitosan hydrogel and investigated its material properties, repair effect, biocompatibility, and histocompatibility in in vitro and in vivo study. In vitro and in vivo, the hydrogel has low toxicity, biodegradability, and good biocompatibility. In an animal experiment, this composite hydrogel can effectively fill local tissue defects to maintain the stability of the spine and delay the process of intervertebral disc degeneration after surgery. These results indicated that this composite hydrogel will be a promising way to treat postoperative intervertebral disc disease in future clinical applications.