Nerve is the foundation of the physiological function such as the skin feeling and thermoregulation, and also regulates the regeneration and scar healing of skin wound by multiple mechanisms. Though the denervated skin wound can heal spontaneously, the nerve might accelerate wound healing by activating the neurogenic inflammation and nerve trophism, increasing the blood supply around the wound, promoting the proliferation of fibroblasts and keratinocytes, stimulating the expression of collagen I and III, and interacting with immune system and releasing neuropeptides. If all kinds of repair cells, extracellular matrix, nerve, blood vessel and cutaneous appendages assemble organically, the skin wound regenerates, and otherwise the scar heals. The nerve axon growth occurs mainly in the early stage of the wound healing and the scar rebuilding process, and the nerve growth rate is obviously slower than the granulation tissue formation and cicatrization. Furthermore, the axon growth of different nerve fibers are not entirely the same. The exogenous neuropeptides might promote the wound repair and the nerve regeneration. The antagonist of the neuropeptides or high selective nerve abscission might reduce the scar hyperplasia. Therefore, it contribute to find methods to promote the regeneration of skin wound and peripheral nerve injury by understanding the effects and regulatory mechanism of both nerve and various repair elements in regeneration or scar healing of skin wound.

OBJECTIVE To investigate the pharmacokinetic characteristics of crossbow microemulsion in rabbit skin.METH-ODS The concentrations of chlorogenic acid,benzoyl new aconitine,periplocin and new aconitine were determined by UPLC.The effects of temperature,perfusion speed and mass concentration on the recovery rate of the probe were investigated by incremental and decrement methods,the changes of multi-component content in the dialysate at different time points after transdermal administration of crossbow microemulsion were determined by UPLC,and DAS 2.0 software was used to process the data.RESULTS The recovery rate of the probe increased with increasing temperature,and the higher the flow rate,the lower the recovery rate.The pharmacokinetic parameters of chlorogenic acid,benzoyl new aconitine,periplocin and new aconitine in microemulsion Cmax were(3.24±0.39)(1.04±0.29)(4.78±2.15)(2.86±0.55)μg·mL-1,respectively,and in AUC0-∞ were(52.42±30.84)(7.70±3.73)(42.23±13.93)(22.68±12.51)h·mg·mL-1,respectively.CONCLUSION A real-time in vivo microdialysis sampling technique was first used and a UPLC detection technique was established to study the skin pharmacokinetics of multi-components of crossbow microe-mulsion after transdermal administration,which provides a reference for the follow-up investigation and application of crossbow microe-mulsion.

In order to develop a positive quality control products for the detection of porcine repro-ductive and respiratory syndrome virus(PRRSV)nucleic acid by real-time fluorescent quantitative PCR(RT-qPCR),the positive quality control products of PRRSV-1 and PRRSV-2 M genes were prepared using armored RNA technology of MS2 phage.PRRSV-1 and PRRSV-2 M genes were amplified,purified and recovered,and ligated into pET28b vector containing MS2 mature enzyme protein gene and capsid protein.After transformed into BL21(DE3),the gene products were in-duced by IPTG and purified by PEG6000 precipitation method to prepare the armored RNA virus-like particles(AR-PRRSV)containing PRRSV M gene.Following the performance evaluation,as the positive quality control products of PRRSV-1 and PRRSV-2 M genes,AR-PRRSV1M and AR-PRRSV2M were calculated using YY/T 1652-2019 standard.Results showed that it had a good u-niformity,stable storage for the armored virus-like particles at-20,4,25 ℃ for 60 d,and 37 ℃ for 30 d.The prepared armored virus-like particles AR-PRRSV1M and AR-PRRSV2M were deter-mined by digital quantitative PCR(ddPCR)after preliminary quantification by RT-qPCR.The 104 copies/μL of AR-PRRSV1M and AR-PRRSV2M ddPCR fixation was(1.33+0.50)× 104 cop-ies/μL.The above results indicates that the AR-PRRSVM can be used as the quality control of the whole detection process(nucleic acid extraction,reverse transcription and RT-qPCR).

Ex vivo culture-amplified mesenchymal stem cells (MSCs) have been studied because of their capacity for healing tissue injury. MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells, but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period. Hence, strategies to increase the efficacy of MSC treatment are urgently needed. Iron overload, reactive oxygen species deposition, and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs, thereby hastening cell death. Notably, oxidative stress (OS) and deficient antioxidant defense induced by iron overload can result in ferroptosis. Ferroptosis may inhibit cell survival after MSC transplantation, thereby reducing clinical efficacy. In this review, we explore the role of ferroptosis in MSC performance. Given that little research has focused on ferroptosis in transplanted MSCs, further study is urgently needed to enhance the in vivo implantation, function, and duration of MSCs.
Humans ; Antioxidants/metabolism* ; Ferroptosis ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stem Cells ; Iron Overload/metabolism*