Suchergebnisse

Zhiwei Wang,* Ming Li,* Baoqing Yu, Liehu Cao, Qingsong Yang, Jiacan SuDepartment of Orthopedics, Shanghai Hospital, Second Military Medical University, Shanghai, People's Republic of China *These authors contributed equally to this workAbstract: A bioactive composite of nano calcium-deficient apatite (n-CDAP) with an atom molar ratio of calcium to phosphate (Ca/P) of 1.50 and poly(ε-caprolactone)–poly(ethylene glycol)–poly(ε-caprolactone) (PCL–PEG–PCL) was synthesized, and a composite scaffold was fabricated. The composite scaffolds with 40 wt% n-CDAP contained well interconnected macropores around 400 µm, and exhibited a porosity of 75%. The weight-loss ratio of the n-CDAP/PCL–PEG–PCL was significantly greater than nano hydroxyapatite (n-HA, Ca/P = 1.67)/PCL–PEG–PCL composite scaffolds during soaking into phosphate-buffered saline (pH 7.4) for 70 days, indicating that n-CDAP-based composite had good degradability compared with n-HA. The viability ratio of MG-63 cells was significantly higher on n-CDAP than n-HA-based composite scaffolds at 3 and 5 days. In addition, the alkaline phosphatase activity of the MG-63 cells cultured on n-CDAP was higher than n-HA-based composite scaffolds at 7 days. Histological evaluation showed that the introduction of n-CDAP into PCL–PEG–PCL enhanced the efficiency of new bone formation when the composite scaffolds were implanted into rabbit bone defects. The results suggested that the n-CDAP-based composite exhibits good biocompatibility, biodegradation, and osteogenesis in vivo.Keywords: nano calcium-deficient apatite, composite scaffold, degradability, cell responses, osteogenesis

Wei Liang,1,* Yunfei Niu,2,* Shuhua Ge,1 Shaojun Song,2 Jiacan Su,2 Zhuojing Luo11Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China; 2Department of Orthopedics, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China*These authors contributed equally to this workAbstract: We report the synthesis of nanoapatite crystals via a hydrothermal reaction of hydroxyapatite precipitates. The impact of the reaction conditions on the properties of the crystals obtained were evaluated. The hydrothermal reaction that takes place markedly affected the crystallinity, morphology, and size of the nanoapatite crystals formed. High crystallinity and large crystal size were obtained at higher hydrothermal temperatures and longer hydrothermal reaction times. The nanoapatite crystals were needle-like when prepared under ambient pressure conditions and rod-like when prepared under increased pressure. The crystals prepared at ambient pressure had a larger aspect ratio compared with those prepared under increased pressure. The aging time of the initial hydroxyapatite precipitate significantly affected growth of the nanoapatite crystals. With other hydrothermal reaction conditions being equal, the fresh hydroxyapatite precipitate produced notably larger crystals than the aged hydroxyapatite precipitate. The influence of apatite morphology on osteoblast viability was studied by MTT assay. The results indicate that the rod-like apatite showed a better biological response than needle-like apatite in promoting cell growth. Transmission electron microscopy showed that large quantities of needle apatite entered into cells and damaged their morphology.Keywords: nanoapatite crystals, hydrothermal treatment, morphology, cell viability

Wenhua Song,1,* Xiangde Li,1,* Jun Qian,1 Guoyu Lv,2 Yonggang Yan,2 Jiacan Su,3 Jie Wei1 1Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People's Republic of China; 2College of Physical Science and Technology, Sichuan University, Chengdu, People's Republic of China; 3Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China *These authors contributed equally to this paper Abstract: Mesoporous calcium–silicon xerogels with a pore size of 15 nm (MCS-15) and pore volume of 1.43 cm3/g were synthesized by using 1,3,5-mesitylene (TMB) as the pore-expanding agent. The MCS-15 exhibited good degradability with the weight loss of 50 wt% after soaking in Tris-HCl solution for 56 days, which was higher than the 30 wt% loss shown by mesoporous calcium–silicon xerogels with a pore size of 4 nm (MCS-4). The pore size and pore volume of MCS-15 had significant influences on load and release of recombinant human bone morphogenetic protein-2 (rhBMP-2). The MCS-15 had a higher capacity to encapsulate a large amount of rhBMP-2; it could adsorb 45 mg/g of rhBMP-2 in phosphate-buffered saline after 24 hours, which was more than twice that with MCS-4 (20 mg/g). Moreover, the MCS-15 system exhibited sustained release of rhBMP-2 as compared with MCS-4 system (showing a burst release). The MCS-15/rhBMP-2 system could promote the proliferation and differentiation of human mesenchymal stem cells, showing good cytocompatibility and bioactivity. The results indicated that MCS-15, with larger mesopore size and higher pore volume, might be a promising carrier for loading and sustained release of rhBMP-2, which could be used as bone repair material with built-in osteoinduction function in bone reconstruction. Keywords: mesoporous calcium–silicon xerogels, pore size, pore volume, load-release, rhBMP-2

Jiacan Su, Liehu Cao, Baoqing Yu, Shaojun Song, Xinwei Liu, Zhiwei Wang, Ming LiDepartment of Orthopedics, Changhai Hospital, Second Military Medical University, Shanghai, ChinaAbstract: A bone-implanted porous scaffold of mesoporous bioglass/polyamide composite (m-BPC) was fabricated, and its biological properties were investigated. The results indicate that the m-BPC scaffold contained open and interconnected macropores ranging 400–500 µm, and exhibited a porosity of 76%. The attachment ratio of MG-63 cells on m-BPC was higher than polyamide scaffolds at 4 hours, and the cells with normal phenotype extended well when cultured with m-BPC and polyamide scaffolds. When the m-BPC scaffolds were implanted into bone defects of rabbit thighbone, histological evaluation confirmed that the m-BPC scaffolds exhibited excellent biocompatibility and osteoconductivity, and more effective osteogenesis than the polyamide scaffolds in vivo. The results indicate that the m-BPC scaffolds improved the efficiency of new bone regeneration and, thus, have clinical potential for bone repair.Keywords: mesoporous bioglass, polyamide, composite scaffolds, biocompatibility, bone repair

Jun Hou,1 Donghui Fan,2 Lingming Zhao,2 Baoqin Yu,3 Jiacan Su,3 Jie Wei,2 Jung-Woog Shin4 1The First Affiliated Hospital of Anhui Medical University, Department of Oral and Maxillofacial Surgery, Hefei, 2Key Laboratory for Ultrafine Materials of Ministry of Education and The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 3Department of Orthopaedics Trauma, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China; 4Department of Biomedical Engineering, Inje University, Gimhae, Republic of Korea Abstract: Biocomposite scaffolds were fabricated by incorporation of nanobredigite (n-BD) into the polymer of poly(ε-caprolactone)–poly(ethyleneglycol)–poly(ε-caprolactone) (PCL–PEG–PCL). The results revealed that the addition of n-BD into PCL–PEG–PCL significantly improved water absorption, compressive strength, and degradability of the scaffolds of n-BD/PCL–PEG–PCL composite (n-BPC) compared with PCL–PEG–PCL scaffolds alone. In addition, the proliferation and alkaline phosphatase activity of MG63 cells cultured on n-BPC scaffolds were obviously higher than that cultured on PCL–PEG–PCL scaffolds. Moreover, the results of the histological evaluation from the animal model revealed that the n-BPC scaffolds significantly improved new bone formation compared with the PCL–PEG–PCL scaffolds, indicating good osteogenesis. The n-BPC scaffolds with good biocompatibility could stimulate cell proliferation, differentiation, and bone tissue regeneration and would be an excellent candidate for bone defect repair. Keywords: nanobredigite, PCL–PEG–PCL, biocomposite scaffolds, degradability, osteo­genesis

Yun Gyeong Kang,1 Jie Wei,2 Ji Won Shin,1 Yan Ru Wu,3 Jiacan Su,4 Young Shik Park,5 Jung-Woog Shin1,3,6 1School of Biomedical Engineering, Inje University, Gimhae, Republic of Korea; 2Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai, China; 3Department of Health Science and Technology, Inje University, Gimhae, Republic of Korea; 4Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, China; 5School of Biological Science, Inje University, Gimhae, Republic of Korea; 6Cardiovascular and Metabolic Disease Center/Institute of Aged Life Redesign/UHARC, Inje University, Gimhae, Republic of Korea Background: Successful bone tissue engineering using scaffolds is primarily dependent on the properties of the scaffold, including biocompatibility, highly interconnected porosity, and mechanical integrity. Methods: In this study, we propose new composite scaffolds consisting of mesoporous magnesium silicate (m_MS), polycaprolactone (PCL), and wheat protein (WP) manufactured by a rapid prototyping technique to provide a micro/macro porous structure. Experimental groups were set based on the component ratio: (1) WP0% (m_MS:PCL:WP =30:70:0 weight per weight; w/w); (2) WP15% (m_MS:PCL:WP =30:55:15 w/w); (3) WP30% (m_MS:PCL:WP =30:40:30 w/w). Results: Evaluation of the properties of fabricated scaffolds indicated that increasing the amount of WP improved the surface hydrophilicity and biodegradability of m_MS/PCL/WP composites, while reducing the mechanical strength. Moreover, experiments were performed to confirm the biocompatibility and osteogenic differentiation of human mesenchymal stem cells (MSCs) according to the component ratio of the scaffold. The results confirmed that the content of WP affects proliferation and osteogenic differentiation of MSCs. Based on the last day of the experiment, ie, the 14th day, the proliferation based on the amount of DNA was the best in the WP30% group, but all of the markers measured by PCR were the most expressed in the WP15% group. Conclusion: These results suggest that the m_MS/PCL/WP composite is a promising candidate for use as a scaffold in cell-based bone regeneration. Keywords: mesoporous magnesium silicate, wheat protein, scaffold, bone tissue engineering, osteogenic differentiation

Liehu Cao,1,* Weizong Weng,1,* Xiao Chen,1,* Jun Zhang,1 Qirong Zhou,1 Jin Cui,1 Yuechao Zhao,1 Jung-Woog Shin,2 Jiacan Su1 1Department of Orthopaedics Trauma, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China; 2Department of Biomedical Engineering, Inje University, Gimhae, Republic of Korea *These authors contributed equally to this work Abstract: Nanoporous lithium doping magnesium silicate (nl-MS) was introduced into calcium sulfate hemihydrate to prepare calcium sulfate composite (nl-MSC) bone cements. The introduction of nl-MS improved the in vitro degradability of nl-MSC cements, which could neutralize acidic degradable products of calcium sulfate and prevented the pH from dropping. The cements were implanted into the bone defects of femur bone of rabbits, and the results of histological and immunohistochemical analysis revealed that massive new bone tissue formed in the defects while the cements were degradable, indicating that the osteogenesis and degradability of the nl-MSC cements were much better than the control calcium sulfate dihydrate (CSD) cements. Furthermore, the positive expression of vascular endothelial growth factor and collagen type I for nl-MSC cements was higher than CSD, indicating that addition of nl-MS into the cements enhanced vascularization and osteogenic differentiation. The results suggested that the nl-MSC cements with good biocompatibility and degradability could promote vascularization and osteogenesis, and had great potential to treat bone defects. Keywords: bone cements, nanoporous lithium doping magnesium silicate, degradability, vascularization, osteogenesis

Zhaoying Wu,1 Quan Li,2 Yongkang Pan,1 Yuan Yao,1 Songchao Tang,1 Jiacan Su,2 Jung-Woog Shin,3 Jie Wei,1 Jun Zhao4,5 1Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, 2Department of Orthopaedics Trauma, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China; 3Department of Biomedical Engineering, Inje University, Gimhae, Republic of Korea; 4Department of Orthodontics, 5Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, Ninth People's Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine, Shanghai, People's Republic of China Abstract: Bioactive composite macroporous scaffold containing nanoporosity was prepared by incorporation of nanoporous magnesium silicate (NMS) into poly(butylene succinate) (PBSu) using solvent casting–particulate leaching method. The results showed that the water absorption and in vitro degradability of NMS/PBSu composite (NMPC) scaffold significantly improved compared with magnesium silicate (MS)/PBSu composite (MPC) scaffold. In addition, the NMPC scaffold showed improved apatite mineralization ability, indicating better bioactivity, as the NMPC containing nanoporosity could induce more apatite and homogeneous apatite layer on the surfaces than MPC scaffold. The attachment and proliferation of MC3T3-E1 cells on NMPC scaffold increased significantly compared with MPC scaffold, and the alkaline phosphatase (ALP) activity of the cells on NMPC scaffold was expressed at considerably higher levels compared with MPC scaffold. Moreover, NMPC scaffold with nanoporosity not only had large drug loading (vancomycin) but also exhibited drug sustained release. The results suggested that the incorporation of NMS into PBSu could produce bioactive composite scaffold with nanoporosity, which could enhance water absorption, degradability, apatite mineralization and drug sustained release and promote cell responses. Keywords: nanocomposite, degradability, apatite mineralization, cell behaviors, drug release

Weizong Weng,1,2,* Xiaoqun Li,1,* Wei Nie,3 Haoyuan Liu,2 Shanshan Liu,2 Jianming Huang,2 Qirong Zhou,1 Jia He,1 Jiacan Su,1 Zhifeng Dong,4 Dongliang Wang5 1Department of Orthopeadics, Changhai Hospital affiliated to the Second Military Medical University, Shanghai 200433, People's Republic of China; 2Orthopaedics Department, Chenggong Hospital Affilaited to Xiamen University, Xiamen 361000, People's Republic of China; 3College of Chemistry, Chemical Engineering and Biotechnology, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, People's Republic of China; 4Department of Cardiology, Shanghai Sixth Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai 200233, People's Republic of China; 5Orthopeadics Department, Xinhua Hospital Affiliated to the Shanghai Jiaotong University, Shanghai 200433, People's Republic of China*These authors contributed equally to this workCorrespondence: Dongliang Wang; Weizong Weng Email wangdongliang@xinhuanmed.com.cn; drwengweizong@163.comBackground: Bactericidal capacity, durable inhibition of biofilm formation, and a three-dimensional (3D) porous structure are the emphases of infected bone defect (IBD) treatment via local scaffold implantation strategy.Purpose: In this study, silver nanoparticle (AgNP)-loaded nano-hydroxyapatite (nHA)@ reduced graphene oxide (RGO) 3D scaffolds (AHRG scaffolds) were designed to alleviate bone infection, inhibit biofilm formation, and promote bone repair through the synergistic effects of AgNPs, RGO, and nHA.Materials and Methods: AHRGs were prepared using a one-step preparation method, to create a 3D porous scaffold to facilitate a uniform distribution of AgNPs and nHA. Methicillin-resistant Staphylococcus aureus (MRSA) was used as a model-resistant bacterium, and the effects of different silver loadings on the antimicrobial activity and cytocompatibility of materials were evaluated. Finally, a rabbit IBD model was used to evaluate the therapeutic effect of the AHRG scaffold in vivo.Results: The results showed successful synthesis of the AHRG scaffold. The ideal 3D porous structure was verified using scanning electron microscopy and transmission electron microscopy, and X-ray photoelectron spectroscopy and selected area electron diffraction measurements revealed uniform distributions of AgNP and nHA. In vitro antibacterial and cytocompatibility indicated that the 4% AHRG scaffolds possessed the most favorable balance of bactericidal properties and cytocompatibility. In vivo evaluation of the IBD model showed promising treatment efficacy of AHRG scaffolds.Conclusion: The as-fabricated AHRG scaffolds effectively eliminated infection and inhibited biofilm formation. IBD repair was facilitated by the bactericidal properties and 3D porous structure of the AHRG scaffold, suggesting its potential in the treatment of IBDs.Keywords: biofilm, graphene oxide, hydroxyapatite, infected bone defect, scaffold, silver nanoparticles, three-dimensional