Bio-medical materials and engineering最新文献

{"title":"Normal coronal kinematics of dynamic alignment and bony positions relative to the ground in three-dimensional motion analysis during gait: A preliminary study.","authors":"Yasuyuki Tomiyama,&nbsp;Tomoharu Mochizuki,&nbsp;Osamu Tanifuji,&nbsp;Katsutoshi Nishino,&nbsp;Masaei Tanaka,&nbsp;Go Omori,&nbsp;Noriaki Yamamoto,&nbsp;Hiroshi Koga,&nbsp;Yoshio Koga,&nbsp;Hiroyuki Kawashima","doi":"10.3233/BME-211383","DOIUrl":"https://doi.org/10.3233/BME-211383","url":null,"abstract":"<p><strong>Background: </strong>During gait, healthy knee coronal kinematics of each bony axis and lower extremity alignment are important because they could be useful as reference data for several surgeries and provide clarification of the etiology of diseases around the knee in healthy participants; however, it remains unknown.</p><p><strong>Objective: </strong>The objective of this study was to clarify the kinematics of lower extremity alignment and the bony axes relative to the ground during gait, focused on the coronal plane, in healthy individuals by applying our unique three-dimensional (3D) motion analysis.</p><p><strong>Methods: </strong>The study included 21 healthy individuals, including 9 healthy females and 12 healthy males with an average age of 36 ± 17 years. Knee kinematics were calculated in a gait analysis by combining the data from a motion-capture system and a 3D lower-extremity alignment assessment system on biplanar long-leg radiographs by using a 3D-2D registration technique. The main kinematic parameters were the dynamic position change relative to the ground, applying the femoral anatomical axis (FAA), tibial anatomical axis (TAA), and dynamic alignment in the coronal plane during the stance phase of gait.</p><p><strong>Results: </strong>The average changes in FAA, TAA, and dynamic varus alignment were 3.7° ± 1.2°, 3.5° ± 0.8°, and 3.0° ± 1.2°, respectively. The TAA tilted laterally during the loading response and a plateau area appeared afterwards; the FAA gradually inclined laterally until the terminal stance phase, and the dynamic alignment showed varus angular change during the loading response.</p><p><strong>Conclusions: </strong>The tibia and femur were found to change approximately 2-5° of the position of the bony axes relative to the ground. In terms of clinical relevance, our findings can be used to clarify the etiology of diseases around the knee joint and as reference data for surgeries.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":"34 1","pages":"37-49"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9120243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of different remineralization agents in the treatment of natural caries-affected dentin in permanent teeth.","authors":"Ece Yilmazkasapoglu Turkay,&nbsp;Betul Kargul,&nbsp;Aysu Karakas Aydinoglu,&nbsp;Afife Binnaz Hazar Yoruc","doi":"10.3233/BME-221396","DOIUrl":"https://doi.org/10.3233/BME-221396","url":null,"abstract":"<p><strong>Background: </strong>In the preventive treatment protocol, providing remineralization of the tissue in demineralized dentin caries is an important step.</p><p><strong>Objective: </strong>In this in vitro study, the effectiveness of remineralization agents in natural caries-affected dentin (NCAD) were investigated.</p><p><strong>Methods: </strong>Forty caries slices were prepared from permanent molar dentin with International Caries Detection and Assessment System (ICDAS 2) (Code 3). The interventions with 8 days pH cycling were as follows: Deionized water (DW); 5% Sodium Fluoride (5% NaF) Varnish; Casein Phosphopeptide-Amorphous Calcium Fluoride Phosphate (CPP-ACFP); Calcium Glyserophosphate (CaGP) + Magnesium (Mg) + Xylitol. DIAGNOdent (Laser Fluorescence, LF), Surface Microhardness (SMH), and X-ray Fluorescence (XRF) Spectroscopy measurements were calculated before and after pH cycling.</p><p><strong>Results: </strong>LF values decreased between 5% NaF, CCP-ACFP and CaGP. NCAD treated with 5% NaF, CaGP and CCP-ACFP exhibited statistically higher hardness compared to the control group. After 5% NaF application, SMH values were significantly higher than the others. There was no statistically significant difference between baseline and after pH cycling hardness of the control group. After cycling, XRF showed that Ca and P concentrations were increased in all groups.</p><p><strong>Conclusion: </strong>The application of agents used in the study could be recommended and promoted as a treatment option of caries dentin for conventional management of caries.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":"34 2","pages":"133-142"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9148540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface analysis of (Ti,Mg)N coated bone fixation devices following the rabbit femur surgery.","authors":"Kenda Sabouni,&nbsp;Yetkin Ozturk,&nbsp;Erkan Kacar,&nbsp;Gamze Torun Kose,&nbsp;Fatma Nese Kok,&nbsp;Muhammet Kursat Kazmanli,&nbsp;Mustafa Kamil Urgen,&nbsp;Sakip Onder","doi":"10.3233/BME-222544","DOIUrl":"https://doi.org/10.3233/BME-222544","url":null,"abstract":"<p><strong>Background: </strong>Magnesium (Mg) enhances the bone regeneration, mineralization and attachment at the tissue/biomaterial interface.</p><p><strong>Objective: </strong>In this study, the effect of Mg on mineralization/osseointegration was determined using (Ti,Mg)N thin film coated Ti6Al4V based plates and screws in vivo.</p><p><strong>Methods: </strong>TiN and (Ti,Mg)N coated Ti6Al4V plates and screws were prepared using arc-PVD technique and used to fix rabbit femur fractures for 6 weeks. Then, mineralization/osseointegration was assessed by surface analysis including cell attachment, mineralization, and hydroxyapatite deposition on concave and convex sides of the plates along with the attachment between the screw and the bone.</p><p><strong>Results: </strong>According to Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analyses; cell attachment and mineralization were higher on the concave sides of the plates from both groups in comparison to the convex sides. However, mineralization was significantly higher on Mg-containing ones. The mean gray value indicating mineralized area after von Kossa staining was found as 0.48 ± 0.01 and 0.41 ± 0.04 on Mg containing and free ones respectively. Similarly, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) analyses showed that hydroxyapatite growth was abundant on the Mg-containing and concave sides of the plates. Enhanced mineralization and strong attachment to bone were also detected in EDS and SEM analyses of Mg-containing screws.</p><p><strong>Conclusion: </strong>These findings indicated that (Ti,Mg)N coatings can be used to increase attachment at the implant tissue interface due to accelerated mineralization, cell attachment, and hydroxyapatite growth.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":"34 5","pages":"459-472"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10661388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of spheroid size on gene expression profiles of a mouse mesenchymal stem cell line in spheroid culture.","authors":"Akiyoshi Kuroda,&nbsp;Ayumi Mineo,&nbsp;Shintaro Shoji,&nbsp;Gen Inoue,&nbsp;Wataru Saito,&nbsp;Hiroyuki Sekiguchi,&nbsp;Masashi Takaso,&nbsp;Kentaro Uchida","doi":"10.3233/BME-221406","DOIUrl":"https://doi.org/10.3233/BME-221406","url":null,"abstract":"<p><strong>Background: </strong>Mesenchymal stem cell (MSC)-based therapies offer potential for bone repair. MSC spheroid cultures may harbor enhanced therapeutic potential over MSC monolayers through increased secretion of trophic factors. However, the impact of spheroid size on trophic factor expression is unclear.</p><p><strong>Objective: </strong>We investigated the effect of spheroid size on trophic factor-related gene expression.</p><p><strong>Methods: </strong>KUM10, a murine MSC line was used. RNA-seq was used to screen the transcriptional profiles of MSC monolayer and spheroid cultures. Differentially expressed genes identified in RNA-seq were evaluated by q-PCR in cultures of 5 × 104 (S group), 5 × 105 (M group), 5 × 106 (L group) cells/well.</p><p><strong>Results: </strong>Comparison of expression levels between KUM10 monolayer and spheroid cultures identified 2140 differentially expressed genes, of which 1047 were upregulated and 1093 were downregulated in KUM10 spheroids. Among these, 12 upregulated genes (Bmp2, Fgf9, Fgf18, Ngf, Pdgfa, Pdgfb, Tgfb1, Vegfa, Vegfc, Wnt4, Wnt5a, Wnt10a) were associated with secretory growth factors. Of these, expression of Fgf9, Fgf18, Vegfa and Vegfc was elevated in the L group, and Pdgfb and Tgfb1 was elevated in the S group.</p><p><strong>Conclusions: </strong>Spheroid size may impact trophic factor expression. Our results will be useful for future studies assessing the utility of MSC spheroids for treating bone injury.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":"34 1","pages":"67-76"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9120240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antibiofilm properties of silver nanoparticles incorporated into polymethyl methacrylate used for dental applications.","authors":"Marine Ortiz-Magdaleno,&nbsp;Luis Sánchez-Vargas,&nbsp;Delia Gardea-Contreras,&nbsp;Verónica Campos-Ibarra,&nbsp;Amaury Pozos-Guillén,&nbsp;Raúl Márquez-Preciado","doi":"10.3233/BME-222513","DOIUrl":"https://doi.org/10.3233/BME-222513","url":null,"abstract":"<p><strong>Background: </strong>Acrylic resins used in dental and biomedical applications do not have antimicrobial properties, their surface is susceptible to colonization of microorganisms.</p><p><strong>Objective: </strong>The aim of this study was to evaluate the antibiofilm properties of silver nanoparticles (AgNPs) deposited in a polymethyl methacrylate (PMMA) surface against a Staphylococcus aureus biofilm.</p><p><strong>Methods: </strong>The PMMA was impregnated with AgNPs by using the in-situ polymerization method. To determine the solubility of the incorporated silver (Ag+) atomic absorption spectrophotometry was used (AAS) at 24 h, 48 h, 7 days, and 30 days. Thirty specimens of PMMA with AgNPs and without NP (control group) were assembled in the CDC Biofilm Bioreactor system with a cell suspension of S. aureus. The specimens were removed at 6, 12, 24, 48, and 72 h to determine the viability profile and quantify the Arbitrary Fluorescence Units (AFU).</p><p><strong>Results: </strong>The AgNPs showed an irregular and quasispherical shape with an average size of 25 nm. AAS analysis demonstrated a low solubility of Ag+. The formation of the S. aureus biofilm increased as the evaluation periods continued up to 72 h. The experimental group showed poor growth, and a decrease in the intensity of the fluorescence demonstrated a statistically significant inhibition of the formation of the biofilm (P < 0.05) in relation to the control group at 6, 12, 24, 48, and 72 h.</p><p><strong>Conclusion: </strong>AgNPs incorporated into PMMA decreased the growth and maturation of S. aureus biofilm.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":"34 4","pages":"357-373"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9787000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An in vivo preclinical study assessing biocompatibility of Pd-based bulk metallic glass.","authors":"Lukasz Witek,&nbsp;Vasudev Vivekanand Nayak,&nbsp;Ricardo Rodriguez Colon,&nbsp;Andrea Torroni,&nbsp;Marios D Demetriou,&nbsp;Paulo G Coelho","doi":"10.3233/BME-221392","DOIUrl":"https://doi.org/10.3233/BME-221392","url":null,"abstract":"<p><strong>Background: </strong>The bulk metallic glass (BMG), Pd79Ag3.5P6Si9.5Ge2, has a high fracture toughness and has been found to accommodate post-yield stress, unlike most other BMG. Moreover, due to its greater noble gas composition it has a intrinsic corrosion resistance, ideal for dental and orthopedic implants.</p><p><strong>Objective: </strong>This present study aimed to evaluate the in vivo application of Pd79Ag3.5P6Si9.5Ge2 in a large translational sheep model to assess its efficacy to be utilized as an endosteal device.</p><p><strong>Methods: </strong>Twelve implants in the form of cylindrical rods (3 mm in diameter) were produced through rapid quenching. Each sheep (n = 12) received one osteotomy in the mandibular region using rotary instrumentation, which was filled with Pd79Ag3.5P6Si9.5Ge2. After 6- and 24-weeks the animals were euthanized, and samples collected en bloc to conduct histomorphometric analysis. The degree of osseointegration were assessed through bone-to-implant contact (BIC).</p><p><strong>Results: </strong>All samples revealed favorable BIC along with with fibrous connective tissue layers at both 6- and 24-weeks. Bone along with interfacial remodeling was observed in proximity with the metallic glass surface at 6 weeks with higher degrees of bone organization being observed at the later healing time, 24 weeks.</p><p><strong>Conclusions: </strong>The synthesized BMG, given its unique combination of toughness and strength, revealed potential to serve as an alternative to commonly used Ti alloys.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":"34 3","pages":"215-223"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9500547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of ellagic acid and retinoic acid on collagen and elastin production by human dermal fibroblasts.","authors":"Chloe Duckworth,&nbsp;Jada Stutts,&nbsp;Kayla Clatterbuck,&nbsp;Nasim Nosoudi","doi":"10.3233/BME-230007","DOIUrl":"https://doi.org/10.3233/BME-230007","url":null,"abstract":"<p><strong>Background: </strong>Elastin is a fibrous protein key to the structure and support of skin as well as other organ tissues. Elastic fibers are located in the skin's dermal layer and make up approximately 2%-4% of the fat-free dry weight of the dermis in the skin of adults. Aging causes the progressive degradation of elastin fibers. Loss of these fibers can cause skin sagging and wrinkling, loss of healthy blood vessels and lung capacity, aneurysms, and Chronic Obstructive Pulmonary Disease (COPD).</p><p><strong>Objective: </strong>We hypothesized that ellagic acid, a polyphenol, will increase elastin in human dermal fibroblasts (HDF) due to polyphenols' elastin binding properties.</p><p><strong>Method: </strong>We treated HDF's with 2 μg/ml ellagic acid for 28 days to see the elastin deposition in HDF cell cultures. To test this, we treated HDFs with polyphenols ellagic acid for 3, 7, 14 and 21 days. For comparison purposes, we included a group of ellagic acid and retinoic acid since retinoic acid is already in the market for elastin regeneration purposes.</p><p><strong>Results: </strong>When ellagic acid and retinoic acid were introduced together, insoluble elastin and collagen deposition were significantly higher in HDFs compared to other groups.</p><p><strong>Conclusion: </strong>Polyphenols and retinoic acid can improve skin extracellular matrix production of elastin and collagen and may improve skin fine wrinkles.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":"34 5","pages":"473-480"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10661393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topological optimization of anterior cervical plate (ACP) and its biomechanic characteristics.","authors":"Peng Ye, Rongchang Fu, Zhaoyao Wang","doi":"10.3233/BME-230019","DOIUrl":"10.3233/BME-230019","url":null,"abstract":"<p><strong>Background: </strong>Currently, quadrilateral anterior cervical plate (QACP) is a highly prevalent ACP.</p><p><strong>Objective: </strong>This study aims to design a novel ACP using topology optimization (TOACP).</p><p><strong>Methods: </strong>A completed model for C1-C7 cervical segments was established and validated. QACP and TOACP cage systems were implanted within two cervical vertebrae models, respectively, and peak stresses and stress distributions for screw, plate, endplate and cage displacement were investigated under differing exercise modes.</p><p><strong>Results: </strong>Stress levels upon QACP screw were maximized for over-extension exercise (243.3 MPa, 3.35% > TOACP screw). Stress level upon TOACP plate was maximized for over-extension exercise (118.2 MPa, 7.26% > QACP screw). Following QACP cage system implantation, stress on endplate and cage displacement were maximized for extension exercise, which were 27.1%, and 6.3% > TOACP cage system, respectively. Finite element analysis results revealed that topological optimization of the plate can effectively reduce screw stress, thereby enhancing cervical segments' stability during surgery. Furthermore, stress on endplate and cage displacement decreased, indicating great potential in cage sinking and fusion enhancement.</p><p><strong>Conclusions: </strong>Topological optimization of the plate equips the cage system with advantages in clinical applications and biomechanical performance, providing alternative solutions and a theoretical basis for ACP design.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":" ","pages":"525-535"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9911791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In situ-formed hyaluronan gel/BMP-2/hydroxyapatite composite promotes bone union in refractory fracture model mice.","authors":"Hiroki Saito, Shintaro Shoji, Akiyoshi Kuroda, Gen Inoue, Ryo Tazawa, Hiroyuki Sekiguchi, Kensuke Fukushima, Masayuki Miyagi, Masashi Takaso, Kentaro Uchida","doi":"10.3233/BME-230021","DOIUrl":"10.3233/BME-230021","url":null,"abstract":"<p><strong>Background: </strong>A combination of synthetic porous materials and BMP-2 has been used to promote fracture healing. For bone healing to be successful, it is important to use growth factor delivery systems that enable continuous release of BMP-2 at the fracture site. We previously reported that in situ-formed gels (IFGs) consisting of hyaluronan (HyA)-tyramine (TA), horseradish peroxidase and hydrogen peroxide enhance the bone formation ability of hydroxyapatite (Hap)/BMP-2 composites in a posterior lumbar fusion model.</p><p><strong>Objective: </strong>We examined the effectiveness of IFGs-HyA/Hap/BMP-2 composites for facilitating osteogenesis in refractory fracture model mice.</p><p><strong>Methods: </strong>After establishing the refractory fracture model, animals were either treated at the site of fracture with Hap harboring BMP-2 (Hap/BMP-2) or IFGs-HyA with Hap harboring BMP-2 (IFGs-HyA/Hap/BMP-2) (n = 10 each). Animals that underwent the fracture surgery but did not receive any treatment were considered the control group (n = 10). We determined the extent of bone formation at the fracture site according to findings on micro-computed tomography and histological studies four weeks following treatment.</p><p><strong>Results: </strong>Animals treated with IFGs-HyA/Hap/BMP-2 demonstrated significantly greater bone volume, bone mineral content and bone union than those treated with vehicle or IFG-HyA/Hap alone.</p><p><strong>Conclusions: </strong>IFGs-HyA/Hap/BMP-2 could be an effective treatment option for refractory fractures.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":" ","pages":"537-544"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10013648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of drug-loaded microspheres with a core-shell structure using silk fibroin and poly lactic-co-glycolic acid and their application.","authors":"Yi Zhang, Lu Wang, Bin Zhao","doi":"10.3233/BME-230012","DOIUrl":"10.3233/BME-230012","url":null,"abstract":"<p><strong>Background: </strong>Advances in bone tissue engineering offer novel options for the regeneration of bone tissue. In the current clinical treatment, the method of accelerating bone tissue regeneration rate by promoting early angiogenesis has been widely accepted.</p><p><strong>Objective: </strong>This study aimed to develop a long-acting slow-release system using the pro-angiogenic drug tetramethylpyrazine (TMPZ) and pro-osteogenic drug icariin (ICA), which can be administered locally to achieve the sequential release of TMPZ and ICA for better clinically efficiency in the treatment of bone defects.</p><p><strong>Methods: </strong>This study aimed to prepare microspheres with a core-shell structure using two polymers, poly lactic-co-glycolic acid and silk fibroin, by coaxial electrostatic spraying. Based on the therapeutic model for bone defects, the pro-angiogenic drug TMPZ and pro-osteogenic drug ICA were encapsulated in the shell and core layers of the microspheres, respectively. Subsequently, TMPZ and ICA were released sequentially to promote early angiogenesis and late osteogenesis, respectively, at the site of the bone defect. The optimal preparation parameters for preparing the drug-loaded microspheres were identified using the univariate controlled variable method. Additionally, microsphere morphology and core-shell structure, such as physical properties, drug-loading properties, in vitro degradation and drug release patterns, were characterised using scanning electron microscope and laser scanning confocal microscopy.</p><p><strong>Results: </strong>The microspheres prepared in this study were well-defined and had a core-shell structure. The hydrophilicity of the drug-loaded microspheres changed compared to the no-load microspheres. Furthermore, in vitro results indicated that the drug-loaded microspheres with high encapsulation and loading efficiencies exhibited good biodegradability and cytocompatibility, slowly releasing the drug for up to three months.</p><p><strong>Conclusion: </strong>The development of the drug delivery system with a dual-step release mechanism has potential clinical applications and implications in the treatment of bone defects.</p>","PeriodicalId":9109,"journal":{"name":"Bio-medical materials and engineering","volume":" ","pages":"503-523"},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9761599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}