Genome editing technology has emerged as a potential therapeutic tool for treating incurable diseases. In particular, the discovery of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas systems and the design of single-guide RNAs (sgRNAs) have revolutionized genome editing applications. Unfortunately, compared with the rapid development of gene-editing tools, the progress in the development of delivery technologies is lagging behind and thus limiting the clinical application of genome editing. To overcome these limitations, researchers have investigated various delivery systems, including viral and non-viral vectors for delivering CRISPR/Cas and sgRNA complexes. As natural endogenous nanocarriers, extracellular vesicles (EVs) present advantages of biocompatibility, low immunogenicity, stability, and high permeability, making them one of the most promising drug delivery vehicles. This review provides an overview of the fundamental mechanisms of EVs from the aspects of biogenesis, trafficking, cargo delivery, and function as nanotherapeutic agents. We also summarize the latest trends in EV-based CRISPR/Cas delivery systems and discuss the prospects for future development. In particular, we put our emphasis on the state-of-the-art engineering strategies to realize efficient cargo packaging and loading. Altogether, EVs hold promise in bridging genome editing in the laboratory and clinical applications of gene therapies by providing a safe, effective, and targeted delivery vehicle.

The emerging clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated system (Cas) gene-editing system represents a promising tool for genome manipulation. However, its low intracellular delivery efficiency severely compromises its use and potency for clinical applications. Nanocarriers, such as liposomes, polymers, and inorganic nanoparticles, have shown great potential for gene delivery. The remarkable development of nanoparticles as non-viral carriers for the delivery of the CRISPR/Cas9 system has shown great promise for therapeutic applications. In this review, we briefly summarize the delivery components of the CRISPR/Cas9 system and report on the progress of nano-system development for CRISPR/Cas9 delivery. We also compare the advantages of various nano-delivery systems and their applications to deliver CRISPR/Cas9 for disease treatment. Nano-delivery systems can be modified to fulfill the tasks of targeting cells or tissues. We primarily emphasize the novel exosome-based CRISPR/Cas9 delivery system. Overall, we review the challenges, development trends, and application prospects of nanoparticle-based technology for CRISPR/Cas9 delivery.

Numerous biological processes are regulated by the intercellular communications arising from extracellular vesicles (EVs) released from cells. However, the mechanisms that regulate the quantity of EV discharged have yet to be understood. While it is known that ATP9A, a P4-ATPase, is involved in endosomal recycling, it is not clear whether it also contributes to the release of EVs and the makeup of exosomal lipids. This study is aimed at exploring the role of human ATP9A in the process of EV release and, further, to analyze the profiles of EV lipids regulated by ATP9A. Our results demonstrate that ATP9A is located in both the intracellular compartments and the plasma membrane. The percentage of ceramides and sphingosine was found to be significantly greater in the control cells than in the ATP9A overexpression and ATP9A knockout groups. However, EV release was greater in ATP9A knockout cells, indicating that ATP9A inhibits the release of EVs. This study revealed the effects of ATP9A on the release of EVs and the lipid composition of exosomes.

Postmenopausal osteoporosis (PMOP) is a common disease that seriously threatens human health. Estrogen deficiency plays an essential role in the pathogenesis of PMOP. MicroRNAs (miRNAs) are involved in the development and progression of PMOP. Therefore, identification of miRNAs in PMOP due to estrogen deficiency may contribute to earlier diagnosis and better treatment of this disease. The rat model of PMOP was established by ovariectomy. After one month of treatment, the knee joints were evaluated by microcomputed tomography and histological analysis. The plasma estrogen levels were quantified by enzyme-linked immunosorbent assays (ELISAs). MiRNA levels were analyzed by high-throughput sequencing and validated using quantitative real-time PCR (qRT-PCR). Two months after ovariectomy, osteoporosis occurred in the subchondral bone of the rats in the PMOP group, while fewer symptoms of osteoporosis occurred in the subchondral bone of the rats with estrogen replacement therapy. Cartilage degeneration was detected in the PMOP group. MiR-29a-3p, miR-93-5p, and miR-486 expression decreased in the PMOP group compared to the control group. After estrogen treatment for one month, the plasma levels of miR-29a-3p, miR-93-5p, and miR-486 recovered to the normal levels. Estrogen eliminated the expression changes in miR-29a-3p, miR-93-5p, and miR-486. The identification of these differentially expressed miRNAs will help elucidate the crucial role of miRNAs in the pathogenesis of PMOP. Our data could lead to the potential utilization of miRNAs in the diagnosis of PMOP and provide a possible therapeutic target for treatment of this disease.

Targeted delivery to the diseased cell or tissue is the key to the successful clinical use of nucleic acid drugs. In particular, delivery of microRNA-140 (miRNA-140, miR-140) into chondrocytes across the dense, nonvascular extracellular matrix of cartilage remains a major challenge. Here, we report the chondrocyte-targeting exosomes as vehicles for the delivery of miR-140 into chondrocytes as a new treatment for osteoarthritis (OA). By fusing a chondrocyte-affinity peptide (CAP) with the lysosome-associated membrane glycoprotein 2b protein on the surface of exosomes, we acquire CAP-exosomes that can efficiently encapsulate miR-140, specifically enter, and deliver the cargo into chondrocytes in vitro. CAP-exosomes, in contrast to nontagged exosome vesicles, are retained in the joints after intra-articular injection with minimal diffusion in vivo. CAP-exosomes also deliver miR-140 to deep cartilage regions through the dense mesochondrium, inhibit cartilage-degrading proteases, and alleviate OA progression in a rat model, pointing toward a potential organelle-based, cell-free therapy of OA.

背景:骨关节炎的治疗一直是临床医师面临的难题.雌激素补充治疗有较多的副作用,而选择性雌激素受体调节剂的治疗作用尚不明确.目的:验证雌激素对大鼠骨关节炎的治疗作用,探讨雷洛昔芬对大鼠骨关节炎是否有治疗作用.方法:通过卵巢切除术联合前交叉韧带离断术和内侧半月板切除术,构建大鼠骨关节炎模型,2个月后检测模型构建结果,成功后分别给予雌激素与雷洛昔芬皮下注射1个月.通过Micro-CT和组织切片检验骨关节炎治疗效果.结果:卵巢切除术联合前交叉韧带离断术和内侧半月板切除术可快速高效构建大鼠骨关节炎模型.雌激素对大鼠骨关节炎有治疗作用,雌激素可有效缓解软骨退变,然而对软骨下骨病变没有治疗作用,骨小梁在各实验组中数量明显降低,最低值仅为空白对照组的0.6倍,分离度显著增加,最高值为空白对照组1.6倍(P<0.01),以上两组数据均提示软骨下骨骨量丢失严重;尚未发现雷洛昔芬对大鼠骨关节炎的治疗作用.结论:雌激素可有效缓解大鼠骨关节炎症状,但仍需研发新型选择性雌激素受体调节剂来治疗骨关节炎.

Background: Estrogen levels regulate changes in osteoarthritis (OA) by inhibiting degradation of the extracellular matrix. Recent in vitro studies have also shown the role of microRNA-140-5p (miR-140-5p). This study aimed to investigate the role of estrogen deficiency, selective modulation of expression of the estrogen receptor (ER), and expression of miR-140-5p in cartilage and subchondral bone remodeling in an ovariectomized rat model of postmenopausal OA. Material/Methods: Female Sprague-Dawley rats included two model groups, ovariectomized (OVX) rats and rats with destabilization of the medial meniscus (DMM) rats. Two months after surgery, estrogen levels were measured by the enzyme- linked immunosorbent assay (ELISA). Three-dimensional (3D) micro-computed tomography (micro-CT) was used to image the knee joints. Rats were treated with subcutaneous injection of estrogen (E2) or the selective estrogen receptor modulator (SERM), raloxifene (RAL), for one month. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect miR-140-5p in serum, and histology of the knee joint cartilage and bone was performed. Results: In the ovariectomized rat model of OA, estrogen therapy reduced the degree of cartilaginous degeneration, while treatment with raloxifene showed no significant effect. Expression levels of miR-140-5p in the OA model group were significantly lower than the control group. Micro-CT showed that in the model group, anterior cruciate ligament dislocation and subchondral bone density were significantly reduced. Conclusions: In an ovariectomized rat model of postmenopausal OA, estrogen deficiency resulted in resorption of subchondral bone and degeneration of articular cartilage.

骨性关节炎(OA)是一种常见的关节退行性疾病,可导致整个关节结构改变,包括关节软骨、软骨下骨和滑膜组织.转化生长因子(TGF)-β是多功能细胞因子,与人体多种器官和组织的病理及生理过程紧密相关.近年,体内和体外实验都表明,TGF-β在OA发生和发展中起关键作用.该文主要就TGF-β信号转导通路对关节软骨、软骨下骨及滑膜的影响作一综述.

骨关节炎(OA)是一种严重损害中老年人健康的骨关节疾病.绝经后女性OA患病率远高于同龄男性及绝经前女性,表明雌激素是参与OA发生和发展的重要调节因子.雌激素需与雌激素受体(ER)结合后起作用,ER包括雌激素核受体(nER)和雌激素膜受体(mER),通过不同作用机制以实现雌激素对关节软骨的保护作用.近期研究发现,OA患者与正常人相比有多种miRNA存在差异性表达,表明miRNA有望成为早期诊治OA的新靶点.本文就雌激素、ER及雌激素和miRNA与OA的研究进展作一综述.

目的:研究在上颌后牙区牙缺失剩余牙槽骨不足3mm的患者中,进行上颌窦底外提同期植入手术的可行性及科学性,并与上颌窦底外提延期植入手术疗效做对比,为选择理想的手术治疗方法提供理论依据.方法:将深圳恒生医院2011年2月至2015年12月收治的上颌后牙区骨量丢失严重(＜3 mm)的49名入组患者按照随机分配的原则分为对照组和观察组.在本研究中,观察组共有26例患者,对照组共有23例患者.观察组患者均采用上颌窦外提升术同期植入种植体,对照组患者均采用上颌窦外提升术延期植入种植体.观察两组患者临床治疗效果及康复情况.结果:两组患者在种植体存留率和稳定性方面比较,差异均无统计学意义(P＞0.05);观察组患者在康复时间上较对照组显著缩短3个月以上.结论:在上颌后牙区剩余牙槽骨＜3mm的患者中,采用上颌窦底外提同期植入手术可取得理想的临床疗效,具有经济高效等诸多优点.

Tibial plateau fractures present in a wide spectrum of injury severity and pattern,which are intra-articular injuries of the knee joint,are often difficult to treat and have a high complication rate,especially the osteoarthritis.Now,the management of complex tibial plateau fractures is ever evolving.To achieve good clinical outcomes,we should start with a thorough evaluation and preoperative planning period,which leads to choosing the most appropriate surgical approach and fixation strategy.In this article we report on the latest advances made in the management of the tibial plateau fractures.

骨性关节炎(Osteoarthritis,OA)又名退行性关节炎,是一种以关节软骨退变为主,最终导致软骨原有结构破坏并伴随滑膜增生及炎症和软骨周围骨质增生的慢性疾病.雌激素是人体中常见激素,参与了人体很多重要生理过程.众所周知, OA的发生受多种因素影响,特别与年龄和性别关系密切[1,2].OA好发于绝经后女性,流行病学调查表明45~64岁的人群中,女性OA患者是男性的3倍[3,4].早在1952年研究就表明雌激素的下降在OA的发生、发展中扮演重要的角色.随后Ushiyama等[5]研究证明,人关节软骨存在两种雌激素受体α和β,表明关节软骨是雌激素靶组织之一.本文拟对雌激素与OA方面的研究进行综述,讨论雌激素在OA发生过程中的作用.

BACKGROUND: As is known to all, cartilage tissue engineering has three elements, seed cells,scaffold materials, and cytokines. Scaffold materials play an important role in cartilage tissue engineering.OBJECTIVE: To search and review the literatures about tissue-engineered cartilage scaffold materials in the last decade,and to discuss problems and the development direction of the scaffolds.METHODS: A computer-based search of relevant articles published from 2006 to 2016 was conducted in PubMed and CNKI using the key words of "cartilage tissue engineering, natural scaffold materials, synthetic scaffold materials,composite scaffolds,nanometer materials" in English and Chinese, respectively.RESULTS AND CONCLUSION:Scaffold materials in cartilage tissue engineering have different sources and kinds.Natural materials, synthetic materials and nanometer materials have their own advantages and disadvantages. Any single material is difficult to meet the clinical requirements of the cartilage. Material compounds with different proportions can be used to prepare scaffolds with good mechanical properties, high porosity, good compatibility and degradation. But there are still some problems, such as excessive speed of scaffold degradation and excessive cell growth. The current research is in in vitro experimental stage mostly, and the application in clinic has not been enforced yet due to small size and lack of a long-term follow up.