The purpose of this study was to explore the different effects between biomimetic mineralized collagen(MC)and ordinary physically blended hydroxyapatite/collagen(HA/Col)composite in evaluating new bone formation and regenerated bone height in human extraction sockets.Thirty-four patients who cannot retain teeth caused by trauma or decay were randomly selected from Department of Stomatology of Dongzhimen Hospital from December 2013 to December 2014.The patients were randomly divided into two groups.After the operation of tooth extraction,17 patients were implanted with biomimetic MC(MC group),and other 17 patients were implanted with ordinary physically blended nHA/Col composite(nHA/Col group).X-ray positioning projection by auto-photographing was taken to test the distance between the lowest position and the neighboring CEJm-CEJd immediately,1 month and 3 months after the operation.The height of new bone formation of the MC group was significantly higher than the nHA/Col group.Biomimetic MC showed better clinical outcomes in the bone formation for extraction site preservation and would have broad application prospect in the field of oral and maxillofacial surgeries.
Lu FengLiang ZhangYun CuiTian-Xi SongZhi-Ye QiuXiu-Mei WangBao-Sheng Tan
The novel hydrogels-grafted IKVAV poly(lactide-co-ethylene oxide-co-fumarate)(PLEOF) hydrogels(GIPHs) were developed. The rat bone marrow mesenchymal stem cells(BMMSCs) were employed, and the cell vitality and apoptosis assays were carried out to evaluate the cytocomptibility of GIPHs. Our data demonstrated that the infl uence of GIPHs on the proliferation of BMMSCs was in a concentration and time dependent manner. The proliferative ability of BMMSCs in GIPHs-treated group(100 μg/mL) after 72 h presented a maximum response which was 30.1% more than that of control group. The numbers of apoptotic cells in GIPHs-treated group(100 μg/mL) were just as much as that of control group after 24 h treatment. The GIPHs are able to provide an appropriate environment for BMMSCs survival and proliferation.
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
In this study, we synthesized degradable PRGD/PDLLA/β-TCP/NGF composites to facilitate neuronal repair. To this end, we (1) examined the release of nerve growth factor (NGF) from the composites, (2) evaluated the differentiation status of the cells and (3) address how transcriptional activity may regulate the differentiation mechanism of these cells. NGF content was determined using enzyme-linked immunosorbent assay, while the cellular mRNA expression was examined by real-time PCR analysis. Our results indicated that NGF release was robust during the first 10 days and then stabilized at a lower level thereafter. Treatment of PC12 cells with the extract of the NGF-embedded composites induced the formation of neurites and, in some cases, net-like neurites. Analysis of the expression level of differentiation-related genes, such as TrkA, VGF, Rab1, GAP43 and β-tubulin Ⅱ, were significantly up-regulated. These findings suggest that these composites might be a suitable delivery system for growth factors like NGF that can be used to facilitate neuronal repair after injury.
