Lei Wang, Hui Fu, Wenwen Wang, Yi Liu, Xumin Li, Jijing Yang, Lingli Li, Gang Wu, Yihuai Pan
Pulp-capping materials are commonly adopted in the clinic to form reparative dentin and thus protect dental pulp tissues from cases of deep caries, accidentally exposed pulps or partial pulpotomy. Some traditional pulp capping materials used in the clinic include calcium hydroxide and mineral trioxide aggregates. However, there are limitations to thin restorative dentin, and a long period of time is needed to cause degenerative changes in dental pulp. In this paper, injectable colloidal gels were developed to induce the formation of reparative dentin through a simple UV method from methacrylic acid functionalized gelatin loaded with notoginsenoside R1 (Gel-MA/NGR1). The results of the physicochemical property examinations showed that the prepared Gel-MA/NGR1 hydrogel possessed an appropriate interconnected porous microarchitecture with a pore size of 10.5 micrometres and suitable mechanical properties with a modulus of 50-60 kPa, enabling cell adhesion and proliferation. The hydrogel remained hydrophilic with sustained drug release performance. In addition, Gel-MA/NGR1 significantly enhanced the odontogenetic differentiation of mouse dental papilla cells by elevating the expression levels of the dentinogenic markers ALP and OCN and extracellular matrix mineralization. In vivo stimulation was carried out by injecting the precursors into the predrilled alveolar cavity of Sprague-Dawley rats followed by immediate in situ UV crosslinking. The results showed that Gel-MA/NGR1 has a strong capacity to promote reparative dentin formation. Haematoxylin & eosin, Masson, and immunohistochemical staining (DMP-1, DSPP, OCN and RUNX2) and micro-CT were employed to illustrate the effectiveness of dentinogenesis, and the relative volumes of calcification were found to have increased ∼175-fold. All of the results showed that the Gel-MA/NGR1 hydrogel promoted reparative dentin formation, which suggests that this hydrogel provides great potential as a pulp-capping material to induce dentin formation.
临床上常用盖髓材料来形成修复性牙本质，从而保护牙髓组织不受深部龋、意外暴露牙髓或部分截髓的影响。临床上常用的传统盖髓材料包括氢氧化钙和矿物三氧化物聚集体。然而，薄化修复牙本质存在局限性，且需要较长时间才能引起牙髓的退行性改变。本文以三七皂苷R1 (Gel-MA/NGR1)为载体，采用简单的紫外法制备了可注射胶体凝胶，诱导修复牙本质的形成。理化性质测试结果表明，制备的Gel-MA/NGR1水凝胶具有合适的互连多孔微结构，孔径为10.5微米，力学性能为50-60 kPa，有利于细胞粘附和增殖。水凝胶保持亲水性，具有持续的药物释放性能。此外，Gel-MA/NGR1通过提高牙本质标志物ALP和OCN的表达水平和细胞外基质矿化水平，显著增强了小鼠牙乳头细胞的成牙分化。通过将前体注射到Sprague-Dawley大鼠的预钻孔肺泡腔中，然后立即原位UV交联进行体内刺激。结果表明，Gel-MA/NGR1具有较强的促进修复性牙本质形成的能力。采用血红素和伊红、马松、免疫组织化学染色(DMP-1、DSPP、OCN和RUNX2)和显微ct来说明牙本质形成的有效性，发现钙化的相对体积增加了~ 175倍。以上结果表明，凝胶- ma /NGR1水凝胶促进修复性牙本质的形成，表明该水凝胶作为牙本质覆盖材料在诱导牙本质形成方面具有很大的潜力。
{"title":"Notoginsenoside R1 Functionalized Gelatin Hydrogels to Promote Reparative Dentinogenesis","authors":"Lei Wang, Hui Fu, Wenwen Wang, Yi Liu, Xumin Li, Jijing Yang, Lingli Li, Gang Wu, Yihuai Pan","doi":"10.2139/ssrn.3677352","DOIUrl":"https://doi.org/10.2139/ssrn.3677352","url":null,"abstract":"Pulp-capping materials are commonly adopted in the clinic to form reparative dentin and thus protect dental pulp tissues from cases of deep caries, accidentally exposed pulps or partial pulpotomy. Some traditional pulp capping materials used in the clinic include calcium hydroxide and mineral trioxide aggregates. However, there are limitations to thin restorative dentin, and a long period of time is needed to cause degenerative changes in dental pulp. In this paper, injectable colloidal gels were developed to induce the formation of reparative dentin through a simple UV method from methacrylic acid functionalized gelatin loaded with notoginsenoside R1 (Gel-MA/NGR1). The results of the physicochemical property examinations showed that the prepared Gel-MA/NGR1 hydrogel possessed an appropriate interconnected porous microarchitecture with a pore size of 10.5 micrometres and suitable mechanical properties with a modulus of 50-60 kPa, enabling cell adhesion and proliferation. The hydrogel remained hydrophilic with sustained drug release performance. In addition, Gel-MA/NGR1 significantly enhanced the odontogenetic differentiation of mouse dental papilla cells by elevating the expression levels of the dentinogenic markers ALP and OCN and extracellular matrix mineralization. In vivo stimulation was carried out by injecting the precursors into the predrilled alveolar cavity of Sprague-Dawley rats followed by immediate in situ UV crosslinking. The results showed that Gel-MA/NGR1 has a strong capacity to promote reparative dentin formation. Haematoxylin & eosin, Masson, and immunohistochemical staining (DMP-1, DSPP, OCN and RUNX2) and micro-CT were employed to illustrate the effectiveness of dentinogenesis, and the relative volumes of calcification were found to have increased ∼175-fold. All of the results showed that the Gel-MA/NGR1 hydrogel promoted reparative dentin formation, which suggests that this hydrogel provides great potential as a pulp-capping material to induce dentin formation.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82025405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-31DOI: 10.5121/ijcsit.2020.12407
Maryamsadat Nejadghaderi
Demographic studies of a disease can reveal the characteristics of that disease among a specific population and will help the physicians to achieve a more accurate perception about it. The demographic of Lichen PlanoPilaris (LPP) among the Iranian population is unknown. The aim of this study is to describe the clinical, demographic, and histopathologic findings of lichen planopilaris in the Iranian population.
{"title":"A Novel Study of Lichen Planopilaris Among Different Iranian Ethnicities based on Computer-aided Programs","authors":"Maryamsadat Nejadghaderi","doi":"10.5121/ijcsit.2020.12407","DOIUrl":"https://doi.org/10.5121/ijcsit.2020.12407","url":null,"abstract":"Demographic studies of a disease can reveal the characteristics of that disease among a specific population and will help the physicians to achieve a more accurate perception about it. The demographic of Lichen PlanoPilaris (LPP) among the Iranian population is unknown. The aim of this study is to describe the clinical, demographic, and histopathologic findings of lichen planopilaris in the Iranian population.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87014138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rapid endothelialization of small-diameter vascular grafts remains a significant challenge in clinical practice. In addition, compliance mismatch causes intimal hyperplasia and finally leads to graft failure. To achieve compliance match and rapid endothelialization, we synthesized low-initial-modulus poly(ester-urethane)urea (PEUU) elastomer and prepared it into electrospun tubular grafts and then functionalized the grafts with poly(ethylene glycol) (PEG) and heparin via covalent self-assembly. The PEG- and heparin-functionalized PEUU (PEUU@PEG-Hep) graft had comparable mechanical properties with the native blood vessel. In vitro data demonstrated that the grafts are of great cytocompatibility and blood compatibility. Covalent self-assembly of PEG and heparin significantly promoted the adhesion, spreading, and proliferation of human umbilical vein endothelial cells (HUVECs) and upregulated the expression of vascular endothelial cell-related genes, as well as increased the capability of grafts in preventing platelet deposition. In vivo assessments indicated good biocompatibility of the PEUU@PEG-Hep graft as it did not induce severe immune responses. Replacement of resected carotid artery with the PEUU@PEG-Hep graft in a rabbit model showed that the graft was capable of rapid endothelialization, initiated vascular remodeling, and maintained patency. This study demonstrates the synergistic effects of compliance match and efficacious antithrombosis of synthetic grafts for blood vessel regeneration.
{"title":"Covalent Self-Assembly of PEG and Heparin Improves Biological Performance of Electrospun Vascular Grafts for Carotid Artery Replacement","authors":"T. Zhu, Hongbing Gu, Hongmei Zhang, Hongsheng Wang, Huitang Xia, X. Mo, Jinglei Wu","doi":"10.2139/ssrn.3647647","DOIUrl":"https://doi.org/10.2139/ssrn.3647647","url":null,"abstract":"Rapid endothelialization of small-diameter vascular grafts remains a significant challenge in clinical practice. In addition, compliance mismatch causes intimal hyperplasia and finally leads to graft failure. To achieve compliance match and rapid endothelialization, we synthesized low-initial-modulus poly(ester-urethane)urea (PEUU) elastomer and prepared it into electrospun tubular grafts and then functionalized the grafts with poly(ethylene glycol) (PEG) and heparin via covalent self-assembly. The PEG- and heparin-functionalized PEUU (PEUU@PEG-Hep) graft had comparable mechanical properties with the native blood vessel. In vitro data demonstrated that the grafts are of great cytocompatibility and blood compatibility. Covalent self-assembly of PEG and heparin significantly promoted the adhesion, spreading, and proliferation of human umbilical vein endothelial cells (HUVECs) and upregulated the expression of vascular endothelial cell-related genes, as well as increased the capability of grafts in preventing platelet deposition. In vivo assessments indicated good biocompatibility of the PEUU@PEG-Hep graft as it did not induce severe immune responses. Replacement of resected carotid artery with the PEUU@PEG-Hep graft in a rabbit model showed that the graft was capable of rapid endothelialization, initiated vascular remodeling, and maintained patency. This study demonstrates the synergistic effects of compliance match and efficacious antithrombosis of synthetic grafts for blood vessel regeneration.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89143626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper empirically examines the relationship between research exemptions – which are mechanisms in patent law that provide shelter to researchers using patented inventions for scientific research from infringement claims – and innovation. We analyze a 2002 court decision (Madey v. Duke University) that has dramatically limited the scope of research exemptions in the United States. The court decision provides us with a quasi-natural policy experiment we leverage to empirically estimate the effects of this policy change on innovation. We use data on patents in the area of genetically modified organisms. Employing a difference-in-difference estimation approach, we find statistically significant evidence that this policy change led to a marked decrease in research conducted in the United States. However, we find no significant effect in research conducted in countries with more liberal research exemptions. Our results suggest that there is a negative relationship between research exemptions and genetically modified seed patents. We also find that U.S. researchers still engage in co-invention with their domestic peers, suggesting that they have not yet strategically adapted to this policy change and new research environment. The oligopolistic market structure of the genetically modified seed industry may stifle an active relocation of research abroad, thereby hindering innovation.
{"title":"Do Patent Systems Deter Innovation in a Genetically Modified Seed Research?","authors":"Yeongbin Kim","doi":"10.2139/ssrn.3614876","DOIUrl":"https://doi.org/10.2139/ssrn.3614876","url":null,"abstract":"This paper empirically examines the relationship between research exemptions – which are mechanisms in patent law that provide shelter to researchers using patented inventions for scientific research from infringement claims – and innovation. We analyze a 2002 court decision (Madey v. Duke University) that has dramatically limited the scope of research exemptions in the United States. The court decision provides us with a quasi-natural policy experiment we leverage to empirically estimate the effects of this policy change on innovation. We use data on patents in the area of genetically modified organisms. Employing a difference-in-difference estimation approach, we find statistically significant evidence that this policy change led to a marked decrease in research conducted in the United States. However, we find no significant effect in research conducted in countries with more liberal research exemptions. Our results suggest that there is a negative relationship between research exemptions and genetically modified seed patents. We also find that U.S. researchers still engage in co-invention with their domestic peers, suggesting that they have not yet strategically adapted to this policy change and new research environment. The oligopolistic market structure of the genetically modified seed industry may stifle an active relocation of research abroad, thereby hindering innovation.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82251178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For clinical detection of cardiac function such as ejection fraction, end-systolic volume and end-diastolic volume used MRI (Magnetic Resonance Images). These functions were evaluated from experts manually or semi-automatically, they were time-consuming and tedious. This paper applies the automatic evolution of inner contour and outer contour on the MICCAI 2012 database of cardiac MRI. This paper gives optimistic results in terms of the boundary line and cross-section area of the epicardium and endocardium of the left ventricle. This paper will be useful for experts to quantify the endocardium and epicardium for Cardiac Vascular Diseases (CVD) type.
{"title":"Extraction Endocardium and Epicardium of Left Ventricle using Internal and External Energy Terms of Signed Distance Function in Cardiac MRI","authors":"S. Pawar, S. Dhanure","doi":"10.2139/ssrn.3646233","DOIUrl":"https://doi.org/10.2139/ssrn.3646233","url":null,"abstract":"For clinical detection of cardiac function such as ejection fraction, end-systolic volume and end-diastolic volume used MRI (Magnetic Resonance Images). These functions were evaluated from experts manually or semi-automatically, they were time-consuming and tedious. This paper applies the automatic evolution of inner contour and outer contour on the MICCAI 2012 database of cardiac MRI. This paper gives optimistic results in terms of the boundary line and cross-section area of the epicardium and endocardium of the left ventricle. This paper will be useful for experts to quantify the endocardium and epicardium for Cardiac Vascular Diseases (CVD) type.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73548622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bone and dentin development requires temporal and spatial deposition of calcium phosphate mineral. Several proteins work in coordination and contribute to this tightly regulated process. STIM1 (Stromal interaction molecule 1) is one such protein that has been recently identified to function in bone and enamel mineralization. STIM1 is a calcium sensor localized on the ER membrane and is well recognized for its physiological role in maintaining calcium homeostasis. We have demonstrated earlier that DMP1 stimulation of preosteoblasts and preodontoblasts stimulate calcium release from internal Ca2+ stores and this store depletion is sensed by STIM1. Store-operated calcium entry (SOCE) is one of the major Ca2+ influx mechanisms following store depletion in the ER. To demonstrate a role for STIM1 in dentin matrix mineralization, we generated transgenic DPSCs in which STIM1 was either overexpressed or silenced. These cells were characterized for their differentiation potential by gene expression analysis, Alizarin Red staining and the topology of the matrix examined by Field Emission Scanning Electron Microscopy (FESEM). Results suggest upregulation of genes involved in mineralization and increased calcium deposition with STIM1 overexpression. FESEM results demonstrate that STIM1 overexpression resulted in release of large amount of extracellular microvesicles and promoted matrix mineralization. Interestingly, knockdown of STIM1 resulted in release of fewer microvesicles and less mineral deposits in the ECM. Reduced dentin thickness, malformed and highly porous alveolar bone of STIM-1 null mice confirmed the role of STIM1 in the formation of calcified tissues. Overall, STIM1 is a crucial molecule in biomineralization as STIM1 can influence intracellular Ca2+ oscillations and thus provide a signal for activation of upstream and downstream effectors to promote precursor cell differentiation and matrix mineralization.
{"title":"STIM1 a Calcium Sensor Promotes the Assembly of an ECM that Contains Extracellular Vesicles and Factors that Modulate Mineralization","authors":"Yinghua Chen, Rahul Koshy, Anne George","doi":"10.2139/ssrn.3568118","DOIUrl":"https://doi.org/10.2139/ssrn.3568118","url":null,"abstract":"Bone and dentin development requires temporal and spatial deposition of calcium phosphate mineral. Several proteins work in coordination and contribute to this tightly regulated process. STIM1 (Stromal interaction molecule 1) is one such protein that has been recently identified to function in bone and enamel mineralization. STIM1 is a calcium sensor localized on the ER membrane and is well recognized for its physiological role in maintaining calcium homeostasis. We have demonstrated earlier that DMP1 stimulation of preosteoblasts and preodontoblasts stimulate calcium release from internal Ca2+ stores and this store depletion is sensed by STIM1. Store-operated calcium entry (SOCE) is one of the major Ca2+ influx mechanisms following store depletion in the ER. To demonstrate a role for STIM1 in dentin matrix mineralization, we generated transgenic DPSCs in which STIM1 was either overexpressed or silenced. These cells were characterized for their differentiation potential by gene expression analysis, Alizarin Red staining and the topology of the matrix examined by Field Emission Scanning Electron Microscopy (FESEM). Results suggest upregulation of genes involved in mineralization and increased calcium deposition with STIM1 overexpression. FESEM results demonstrate that STIM1 overexpression resulted in release of large amount of extracellular microvesicles and promoted matrix mineralization. Interestingly, knockdown of STIM1 resulted in release of fewer microvesicles and less mineral deposits in the ECM. Reduced dentin thickness, malformed and highly porous alveolar bone of STIM-1 null mice confirmed the role of STIM1 in the formation of calcified tissues. Overall, STIM1 is a crucial molecule in biomineralization as STIM1 can influence intracellular Ca2+ oscillations and thus provide a signal for activation of upstream and downstream effectors to promote precursor cell differentiation and matrix mineralization.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82867477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-07DOI: 10.1089/ind.2020.29217.ern
Elizabeth R. Nesbitt
Emerging carbon capture utilization (CCU) technologies potentially allow chemical companies and other manufacturers to capture waste carbon—in the form of carbon monoxide (CO) and/or carbon dioxide...
{"title":"Using Waste Carbon Feedstocks to Produce Chemicals","authors":"Elizabeth R. Nesbitt","doi":"10.1089/ind.2020.29217.ern","DOIUrl":"https://doi.org/10.1089/ind.2020.29217.ern","url":null,"abstract":"Emerging carbon capture utilization (CCU) technologies potentially allow chemical companies and other manufacturers to capture waste carbon—in the form of carbon monoxide (CO) and/or carbon dioxide...","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80968648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.21276/ijircst.2020.8.2.5
A. Y.A, A. O
The extraction of features involves the method of converting the original pixel values of an image to more meaningful, useful and measurable information that can be used in other techniques, such as image processing, pattern recognition and machine learning. The feature extraction plays a predominant role in iris recognition in which also the recognition rate is determined. The effective recognition accuracy, reduction of mis-classification of two iris templates mostly depends on feature extraction techniques. An efficient iris recognition system requires that the discriminating information presents in an iris pattern to be accurately obtained. This paper performed a literature review on different techniques of feature extraction of iris recognition. The recommendation was made on how these techniques can be further enhanced to produce an effective iris recognition system.
{"title":"Feature Extraction Techniques for Iris Recognition System: A Survey","authors":"A. Y.A, A. O","doi":"10.21276/ijircst.2020.8.2.5","DOIUrl":"https://doi.org/10.21276/ijircst.2020.8.2.5","url":null,"abstract":"The extraction of features involves the method of converting the original pixel values of an image to more meaningful, useful and measurable information that can be used in other techniques, such as image processing, pattern recognition and machine learning. The feature extraction plays a predominant role in iris recognition in which also the recognition rate is determined. The effective recognition accuracy, reduction of mis-classification of two iris templates mostly depends on feature extraction techniques. An efficient iris recognition system requires that the discriminating information presents in an iris pattern to be accurately obtained. This paper performed a literature review on different techniques of feature extraction of iris recognition. The recommendation was made on how these techniques can be further enhanced to produce an effective iris recognition system.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85952141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yafeng Wen, Yanan Xu, Weikang Zhao, Jun Wu, Qiming Yang, Sinan Chen, Kai Li, B. Qiao
The structural and functional combination of an implant and living bone is greatly influenced by the surface characteristics of the implant. To enhance the implant-bone interface regarding the osteointegration of nanohydroxyapatite/polyamide66 (nHA/PA66) material, concave microwells that were 100 μm, 200 μm and 400 μm in size (denoted by P100, P200, and P400, respectively) were prepared on the nHA/PA66 substrate surface by selective laser melting (SLM) technology. The surface characteristics of these samples were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), 3D scanning laser microscopy and static water contact angle measurements. We examined the effects of different concave microwell sizes on the adhesion, proliferation and osteogenesis of C3H10T1/2 cells in vitro by cell counting kit-8 (CCK-8), SEM, alkaline phosphatase assay, alizarin red staining, and western blot, and continued our evaluating through micro-CT, histological analysis and push-out tests to verify the osseointegration ability in vivo. P100, P200 and P400 surface modification led to significant increases in concave microwell diameter, depth and surface roughness, and the contact angle measurements showed that only the hydrophilicity of P100 microwells was improved. In vitro testing revealed that P100 microwells could effectively promote the adhesion, proliferation and osteogenic differentiation of C3H10T1/2 cells; in vivo studies further confirmed that P100 microwells significantly increased new bone volume, enhanced bone remodeling, and improved material-bone interface bonding force and instigated rapid osteointegration of nHA/PA66 with host bone. However, these phenomena were not observed for P200 and P400 microwells. Overall, P100 was associated with improved cell adhesion, proliferation and osteogenic differentiation in vitro and greater implant fixation in vivo. These results suggest that surface concave microwell treatment of nHA/PA66 material through SLM technology provides a fast, simple and effective method for clinical applications involving bone tissue regeneration.
{"title":"In Vitro and in Vivo Studies of Selective Laser Melting-Mediated Surface Concave Microwell Treatment to Enhance Osteogenesis and Osseointegration of Nanohydroxyapatite/Polyamide 66 Implants","authors":"Yafeng Wen, Yanan Xu, Weikang Zhao, Jun Wu, Qiming Yang, Sinan Chen, Kai Li, B. Qiao","doi":"10.2139/ssrn.3684929","DOIUrl":"https://doi.org/10.2139/ssrn.3684929","url":null,"abstract":"The structural and functional combination of an implant and living bone is greatly influenced by the surface characteristics of the implant. To enhance the implant-bone interface regarding the osteointegration of nanohydroxyapatite/polyamide66 (nHA/PA66) material, concave microwells that were 100 μm, 200 μm and 400 μm in size (denoted by P100, P200, and P400, respectively) were prepared on the nHA/PA66 substrate surface by selective laser melting (SLM) technology. The surface characteristics of these samples were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), 3D scanning laser microscopy and static water contact angle measurements. We examined the effects of different concave microwell sizes on the adhesion, proliferation and osteogenesis of C3H10T1/2 cells in vitro by cell counting kit-8 (CCK-8), SEM, alkaline phosphatase assay, alizarin red staining, and western blot, and continued our evaluating through micro-CT, histological analysis and push-out tests to verify the osseointegration ability in vivo. P100, P200 and P400 surface modification led to significant increases in concave microwell diameter, depth and surface roughness, and the contact angle measurements showed that only the hydrophilicity of P100 microwells was improved. In vitro testing revealed that P100 microwells could effectively promote the adhesion, proliferation and osteogenic differentiation of C3H10T1/2 cells; in vivo studies further confirmed that P100 microwells significantly increased new bone volume, enhanced bone remodeling, and improved material-bone interface bonding force and instigated rapid osteointegration of nHA/PA66 with host bone. However, these phenomena were not observed for P200 and P400 microwells. Overall, P100 was associated with improved cell adhesion, proliferation and osteogenic differentiation in vitro and greater implant fixation in vivo. These results suggest that surface concave microwell treatment of nHA/PA66 material through SLM technology provides a fast, simple and effective method for clinical applications involving bone tissue regeneration.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86651447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Pei, Mengqi Wang, Wenfang Li, Meiwen Li, Qian Liu, Rui Ding, Jing Zhao, Ang Li, Feng Xu, Guorui Jin
Extracellular matrix remodeling is essential for the development and functions of connective tissues (e.g., heart, muscle and periodontal ligament), where ECM is generally with highly anisotropic features and under mechanical stimulation. However, the nature of how cells remodel their surrounding ECM under mechanical stimulation remains elusive. Herein, we encapsulated human periodontal ligament stem cells (hPDLSCs) within the aligned rat collagen scaffold labeled with fluorescein isothiocyanate (FITC) and provided continuous mechanical stimulation by magnetic stretching. Through tracking the FITC-labeled rat collagen scaffold and the newly secreted human type I collagen, we studied the mechanism of aligned ECM remodeling by encapsulated cells under mechanical stretching. We found that the aligned topography combined with magnetic stretching could significantly promote initial ECM degradation and new ECM secretion: the expression of matrix metalloproteinase 1 and 9 are significantly higher, and the elastic modulus increases from 50 kPa to 75 kPa as compared to the random collagen scaffold encapsulating hPDLSCs. Therefore, we decipher that cells remodel their surrounding ECM under continuous stretching through degradation and then secretion of new ECM to integrate with the aligned ECM and maintain tissue functions. Our study holds great potential in optimization of biomaterial scaffold design for clinical translation.
{"title":"Remodeling of Aligned Fibrous Extracellular Matrix by Encapsulated Cells Under Mechanical Stretching","authors":"D. Pei, Mengqi Wang, Wenfang Li, Meiwen Li, Qian Liu, Rui Ding, Jing Zhao, Ang Li, Feng Xu, Guorui Jin","doi":"10.2139/ssrn.3542979","DOIUrl":"https://doi.org/10.2139/ssrn.3542979","url":null,"abstract":"Extracellular matrix remodeling is essential for the development and functions of connective tissues (e.g., heart, muscle and periodontal ligament), where ECM is generally with highly anisotropic features and under mechanical stimulation. However, the nature of how cells remodel their surrounding ECM under mechanical stimulation remains elusive. Herein, we encapsulated human periodontal ligament stem cells (hPDLSCs) within the aligned rat collagen scaffold labeled with fluorescein isothiocyanate (FITC) and provided continuous mechanical stimulation by magnetic stretching. Through tracking the FITC-labeled rat collagen scaffold and the newly secreted human type I collagen, we studied the mechanism of aligned ECM remodeling by encapsulated cells under mechanical stretching. We found that the aligned topography combined with magnetic stretching could significantly promote initial ECM degradation and new ECM secretion: the expression of matrix metalloproteinase 1 and 9 are significantly higher, and the elastic modulus increases from 50 kPa to 75 kPa as compared to the random collagen scaffold encapsulating hPDLSCs. Therefore, we decipher that cells remodel their surrounding ECM under continuous stretching through degradation and then secretion of new ECM to integrate with the aligned ECM and maintain tissue functions. Our study holds great potential in optimization of biomaterial scaffold design for clinical translation.","PeriodicalId":11894,"journal":{"name":"EngRN: Biomaterials (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78628904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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