In the field of nerve repair,one major challenge is the formation of neuroma.However,reports on both the promotion of nerve regeneration and prevention of traumatic neuroma in the clinical settings are rare in the field of nerve repair.One of the reasons could be the insufficiency in the follow-up system.We have conducted 33 cases of nerve repair using PRGD/PDLLA/b-TCP conduit without any sign of adverse reaction,especially no neuroma formation.Among them,we have selected two cases as representatives to report in this article.The first case was a patient with an upper limb nerve wound was bridged by PRGD/PDLLA/b-TCP conduit and a plate fixation was given.After nearly 3-years’follow-up,the examination results demonstrated that nerve regeneration effect was very good.When the reoperation was performed to remove the steel plate we observed a uniform structure of the regenerated nerve without the formation of neuroma,and to our delight,the implanted conduit was completely degraded 23 months after the implantation.The second case had an obsolete nerve injury with neuroma formation.After removal of the neuroma,the nerve was bridged by PRGD/PDLLA/b-TCP conduit.Follow-up examinations showed that the structure and functional recovery were improved gradually in the 10-month follow-up;no end-enlargement and any other abnormal reaction associated with the characteristic of neuroma were found.Based on our 33-case studies,we have concluded that PRGD/PDLLA/b-TCP nerve conduit could both promote nerve regeneration and prevent neuroma formation;therefore,it is a good alternative for peripheral nerve repair.
Yixia YinBinbin LiQiongjiao YanHonglian DaiXinyu WangJifeng HuangShipu Li
Implant-associated infection remains a difficult medical problem in orthopedic surgery. Therefore, the development of multifunctional bone implants for treating infection and regenerating lost bone tissue, which may be a result of infection, is important. In the present study, we report the fabrication of enoxacin- loaded poly （lactic-co-glycolic acid） （PLGA） coating on porous magnesium scaffold （Enox-PLGA-Mg） which combine the favorable properties of magnesium, the antibacterial property and the effect of inhibition of osteoclastic bone resorption of enoxacin. The drug loaded PLGA coating of Mg scaffold enables higher drug loading efficiency （52%-56%） than non-coating enoxacin loaded Mg scaffold （Enox-Mg） （4%-5%）. Enox- PLGA-Mg exhibits sustained drug release for more than 14 days, and this controlled release of enoxacin signifcantly inhibits bacterial adhesion and prevented biofilm formation by Staphylococcus epidermidis （ATCC35984） and Staphylococcus aureus （ATCC25923）. Biocompatibility tests with Balb/c mouse embryo fibroblasts （Balb/c 3T3 cells） indicate that PLGA-Mg has better biocompatibility than Mg. Finally, we also demonstrate that Enox-PLCA-Mg extract potently inhibited osteoclast formation in vitro. Therefore, Enox- PLCA-Mg has the potential to be used as a multifunctional controlled drug delivery system bone scaffolds to prevent and/or treat orthopedic peri-implant infections.
Yang LiXuqiang LiuLili TanLing RenPeng WanYongqiang HaoXinhua QuKe YangKerong Dai
To investigate the molecular aspects of osteoblastic interactions with β tricalcium phosphate （β-TCP） particles, human osteoblast-like MG-63 cells were cultured with β-TCP particles at a density of 6 mg/mL culture medium for 48 h. Then, the mRNA expression of selected genes were quantified by real-time polymerase chain reaction （PCR）, including the attachment-related genes （α integrin and actin）, the proliferation-related gene （c-jun）, and the osteoblastic markers genes （type I collagen, osteonectin, alkaline phosphatase, RUNX2 and osteoclain）. The results showed that β-TCP particles （the average size 809 nm） significantly promote the attachment and the proliferation of MG-63 cells, and slightly enhance the osteoblastic differentiation based on the analyses of the related genes expression. This study provided scientific evidences to better reveal the underlines of functions of β-TCP in bone repair.
