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He S, Liu W, Wei L, Chen Q, Li Z. A phenomenological model of pulsatile blood pressure-affected degradation of polylactic acid (PLA) vascular stent. Med Biol Eng Comput 2024; 62:1347-1359. [PMID: 38183527 DOI: 10.1007/s11517-023-02998-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 12/09/2023] [Indexed: 01/08/2024]
Abstract
The stent implantation may alter the post-operative patient's blood pressure, and bioresorbable vascular stents (BVS) as a candidate to treat vascular diseases, its degradation is affected by mechanical stress, thus, the altered pressure representing varying stress level will result in different degradation behaviors of the BVS. This paper first proposed a novel stress-regulated PLA degradation model that included swelling factor, and then the degradation evolutions of a PLA BVS within 180 days under normal and high blood pressures were simulated by finite element method, and more four degradation indexes were defined to study the effects of the two blood pressures on the degradation of the PLA BVS. The results showed that the high pressure weakly accelerated the degradation of the PLA BVS with respect to the normal pressure by examining the four indexes, e.g., the residual stent volumev r ( t ) decreased to 0.72 and 0.69, respectively for the normal and high pressures at day 180. The current finding provided a theoretical understanding of the PLA BVS degradation, and hinted that the PLA BVS may not need to be elaborately selected in clinical practices for treating hypertensive patients.
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Affiliation(s)
- Shicheng He
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, People's Republic of China
| | - Wanling Liu
- Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210023, People's Republic of China
| | - Lingling Wei
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230601, People's Republic of China
| | - Qiang Chen
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, People's Republic of China.
| | - Zhiyong Li
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, People's Republic of China.
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD4001, Australia.
- Faculty of Sports Science, Ningbo University, Ningbo, 315211, People's Republic of China.
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Abaei AR, Shine CJ, Vaughan TJ, Ronan W. An integrated mechanical degradation model to explore the mechanical response of a bioresorbable polymeric scaffold. J Mech Behav Biomed Mater 2024; 152:106419. [PMID: 38325169 DOI: 10.1016/j.jmbbm.2024.106419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/17/2024] [Accepted: 01/23/2024] [Indexed: 02/09/2024]
Abstract
Simulation of bioresorbable medical devices is hindered by the limitations of current material models. Useful simulations require that both the short- and long-term response must be considered; existing models are not physically-based and provide limited insight to guide performance improvements. This study presents an integrated degradation framework which couples a physically-based degradation model, which predicts changes in both crystallinity (Xc) and molecular weight (Mn), with the results of a micromechanical model, which predicts the effective properties of the semicrystalline polymer. This degradation framework is used to simulate the deployment of a bioresorbable PLLA (Poly (L-lactide) stent into a mock vessel and the subsequent mechanical response during degradation under different diffusion boundary conditions representing neointimal growth. A workflow is established in a commercial finite element code that couples both the immediate and long-term responses. Clinically relevant lumen loss is reported and used to compare different responses and the effect of neo-intimal tissue regrowth post-implantation on degradation and on the mechanical response is assessed. In addition, the effects of possible changes in Xc, which could occur during processing and stent deployment, are explored.
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Affiliation(s)
- A R Abaei
- Biomechanics Research Centre (BMEC), Biomedical Engineering, School of Engineering, University of Galway, Ireland
| | - Connor J Shine
- Biomechanics Research Centre (BMEC), Biomedical Engineering, School of Engineering, University of Galway, Ireland
| | - T J Vaughan
- Biomechanics Research Centre (BMEC), Biomedical Engineering, School of Engineering, University of Galway, Ireland
| | - W Ronan
- Biomechanics Research Centre (BMEC), Biomedical Engineering, School of Engineering, University of Galway, Ireland.
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Chen J, Xie Y, Li Y, Chen X, Fu M, Liu Y, Zhang Z. Assessment of degradability and endothelialization of modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluders over time in vivo. J Cardiothorac Surg 2023; 18:283. [PMID: 37817186 PMCID: PMC10566106 DOI: 10.1186/s13019-023-02401-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 09/30/2023] [Indexed: 10/12/2023] Open
Abstract
OBJECTIVE To evaluate the fiber-degradation and endothelialization of a modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluder for a long time in vivo. METHODS A total of 57 New Zealand rabbits were selected to establish the vasculature implantation model, which would be used to characterize the mechanical properties and pathological reaction of PLLA filaments (a raw polymer of ASD occluder). In total, 27 Experimental piglets were used to create the ASD model for the catheter implantation of PLLA ASD occluders. Then, X-ray imaging, transthoracic echocardiography, histopathology, and scanning electron microscope (SEM) were performed in the experimental animals at 3, 6, 12, and 24 months after implantation. RESULTS In the rabbit models, the fibrocystic grade was 0 and the inflammatory response was grade 2 at 6 months after vasculature implantation of the PLLA filaments. The mass loss of PLLA filaments increased appreciably with the increasing duration of implantation, but their mechanical strength was decreased without broken. In the porcine models, the cardiac gross anatomy showed that all PLLA ASD occluders were stable in the interatrial septum without any vegetation or thrombus formation. At 24 months, the occluders had been embedded into endogenous host tissue nearly. Pathological observations suggested that the occluders degraded gradually without complications at different periods. SEM showed that the occluders were endothelialized completely and essentially became an integral part of the body over time. CONCLUSION In the animal model, the modified PLLA ASD occluders exhibited good degradability and endothelialization in this long-term follow-up study.
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Affiliation(s)
- Jun Chen
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, Guangdong, China
- Department of Pediatric Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, No. 106 Zhongshan Second Road, Yuexiu District, Guangzhou, 510100, Guangdong, China
- Danzhou People's Hospital, Danzhou, 571700, Hainan, China
| | - Yumei Xie
- Department of Pediatric Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, No. 106 Zhongshan Second Road, Yuexiu District, Guangzhou, 510100, Guangdong, China
| | - Yifan Li
- Department of Pediatric Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, No. 106 Zhongshan Second Road, Yuexiu District, Guangzhou, 510100, Guangdong, China
| | - Xianmiao Chen
- Lifetech Scientific (Shenzhen) Co., Ltd., Shenzhen, 518057, Guangdong, China
| | - Mingjuan Fu
- Lifetech Scientific (Shenzhen) Co., Ltd., Shenzhen, 518057, Guangdong, China
| | - Yanfen Liu
- Lifetech Scientific (Shenzhen) Co., Ltd., Shenzhen, 518057, Guangdong, China
| | - Zhiwei Zhang
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, Guangdong, China.
- Department of Pediatric Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, No. 106 Zhongshan Second Road, Yuexiu District, Guangzhou, 510100, Guangdong, China.
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4
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Dong P, Colmenarez J, Lee J, Hassani NS, Wilson DL, Bezerra HG, Gu L. Load-sharing characteristics of stenting and post-dilation in heavily calcified coronary artery. Sci Rep 2023; 13:16878. [PMID: 37803070 PMCID: PMC10558511 DOI: 10.1038/s41598-023-43160-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 09/20/2023] [Indexed: 10/08/2023] Open
Abstract
In this work, stenting in non-calcified and heavily calcified coronary arteries was quantified in terms of diameter-pressure relationships and load transfer from the balloon to the artery. The efficacy of post-dilation in non-calcified and heavily calcified coronary arteries was also characterized in terms of load sharing and the changes in tissue mechanics. Our results have shown that stent expansion exhibits a cylindrical shape in non-calcified lesions, while it exhibits a dog bone shape in heavily calcified lesions. Load-sharing analysis has shown that only a small portion of the pressure load (1.4 N, 0.8% of total pressure load) was transferred to the non-calcified lesion, while a large amount of the pressure load (19 N, 12%) was transferred to the heavily calcified lesion. In addition, the increasing inflation pressure (from 10 to 20 atm) can effectively increase the minimal lumen diameter (from 1.48 to 2.82 mm) of the heavily calcified lesion, the stress (from 1.5 to 8.4 MPa) and the strain energy in the calcification (1.77 mJ to 26.5 mJ), which are associated with the potential of calcification fracture. Results indicated that increasing inflation pressure can be an effective way to improve the stent expansion if a dog bone shape of the stenting profile is observed. Considering the risk of a balloon burst, our results support the design and application of the high-pressure balloon for post-dilation. This work also sheds some light on the stent design and choice of stent materials for improving the stent expansion at the dog bone region and mitigating stresses on arterial tissues.
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Affiliation(s)
- Pengfei Dong
- Department of Biomedical Engineering and Science, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - Jose Colmenarez
- Department of Biomedical Engineering and Science, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - Juhwan Lee
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Neda Shafiabadi Hassani
- Cardiovascular Imaging Core Laboratory, Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, 44106, USA
| | - David L Wilson
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Hiram G Bezerra
- Interventional Cardiology Center, Heart and Vascular Institute, The University of South Florida, Tampa, FL, 33606, USA
| | - Linxia Gu
- Department of Biomedical Engineering and Science, Florida Institute of Technology, Melbourne, FL, 32901, USA.
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5
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Dong P, Colmenarez J, Lee J, Hassani NS, Wilson DL, Bezerra HG, Gu L. Load-sharing characteristics of stenting and post-dilation in heavily calcified coronary artery. RESEARCH SQUARE 2023:rs.3.rs-3147116. [PMID: 37503304 PMCID: PMC10371149 DOI: 10.21203/rs.3.rs-3147116/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
In this work, stenting in non-calcified and heavily calcified coronary arteries was quantified in terms of diameter-pressure relationships and load transfer from the balloon to the artery. The efficacy of post-dilation in non-calcified and heavily calcified coronary arteries was also characterized in terms of load sharing and the changes in tissue mechanics. Our results have shown that stent expansion exhibits a cylindrical shape in non-calcified lesions, while it exhibits a dog bone shape in heavily calcified lesions. Load-sharing analysis has shown that only a small portion of the pressure load (1.4 N, 0.8% of total pressure load) was transferred to the non-calcified lesion, while a large amount of the pressure load (19 N, 12%) was transferred to the heavily calcified lesion. In addition, the increasing inflation pressure (from 10 to 20 atm) can effectively increase the minimal lumen diameter (from 1.48 mm to 2.82 mm) of the heavily calcified lesion, the stress (from 1.5 MPa to 8.4 MPa) the strain energy in the calcification (1.77 mJ to 26.5 mJ), which associated with the potential of calcification fracture. Results indicated that increasing inflation pressure can be an effective way to improve the stent expansion if a dog bone shape of the stenting profile is observed. Considering the risk of a balloon burst, our results support the design and application of the high-pressure balloon for post-dilation.
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6
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Bhende PP, Chauhan R, Waigaonkar S, Bragança JM, Ganguly A. Composites of Bacillus megaterium H16 derived poly-3-hydroxybutyrate as a biomaterial for skin tissue engineering. Int J Biol Macromol 2023:125355. [PMID: 37327940 DOI: 10.1016/j.ijbiomac.2023.125355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/02/2023] [Accepted: 06/10/2023] [Indexed: 06/18/2023]
Abstract
Composite films of Bacillus megaterium H16 derived PHB with 1%Poly-L-lactic acid (PLLA), 1%Poly-ε-caprolactone (PCL), and 0.3 % graphene nanoplatelets (GNP) were produced by solvent cast method. The composite films were characterized by SEM, DSC-TGA, XRD, and ATR-FTIR. The ultrastructure of PHB and its composites depicted an irregular surface morphology with pores after the evaporation of chloroform. The GNPs were seen to be integrated inside the pores. The B. megaterium H16 derived-PHB and its composites demonstrated good biocompatibility which was evaluated in vitro on HaCaT and L929 cells by MTT assay. The cell viability was best for PHB followed by PHB/PLLA/PCL > PHB/PLLA/GNP > PHB/PLLA. PHB and its composites were highly hemocompatible as it resulted in <1 % hemolysis. The PHB/PLLA/PCL and PHB/PLLA/GNP composites can serve as ideal biomaterials for skin tissue engineering.
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Affiliation(s)
- Prajakta Praveen Bhende
- Department of Biological Sciences, BITS Pilani KK Birla Goa Campus, Zuarinagar, Goa 403726, India.
| | - Rashmi Chauhan
- Department of Chemistry, BITS Pilani KK Birla Goa Campus, Zuarinagar, Goa 403726, India.
| | - Sachin Waigaonkar
- Department of Mechanical Engineering, BITS Pilani KK Birla Goa Campus, Zuarinagar, Goa 403726, India.
| | - Judith M Bragança
- Department of Biological Sciences, BITS Pilani KK Birla Goa Campus, Zuarinagar, Goa 403726, India.
| | - Anasuya Ganguly
- Department of Biological Sciences, BITS Pilani KK Birla Goa Campus, Zuarinagar, Goa 403726, India.
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Wang X, Chen P, Yang H, Liu J, Tu R, Feng HT, Dai H. In Situ Imaging and Anti-inflammation of 3D Printed Scaffolds Enabled by AIEgen. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37200267 DOI: 10.1021/acsami.3c03082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Three-dimensional (3D) printed bioactive scaffolds have been widely used in the field of bone tissue engineering. However, its in vivo visualization and bacterial inflammation are intractable issues during the surgery and treatment. Herein, we first synthesized an aggregation-induced emission-active luminogen (AIEgen) named 4BC with efficient reactive oxygen species (ROS) generation. Then, a series of 3D bioactive scaffolds loaded with 4BC were fabricated by a precipitation adsorption method, namely 4BC@scaffolds, which showed good in situ imaging performance for the implanted scaffolds by using simple UV light irradiation. Among them, the 4BC@TMP scaffold composed of trimagnesium phosphate (TMP) had excellent bactericidal ability for Escherichia coli and Staphylococcus aureus in vitro and resisted bacterial inflammation in vivo through photodynamic action. H&E and immunofluorescence staining were performed to further evaluate the inhibitory effect of bacterial inflammation in vivo. This work verified that AIEgen-based 3D scaffolds are promising bioactive frameworks for bioimaging and antibacterial applications.
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Affiliation(s)
- Xiaoxuan Wang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Pu Chen
- AIE Research Center, College of Chemistry and Chemical Engineering, Baoji University of Arts and Sciences, Baoji 721013, China
| | - He Yang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Jiawei Liu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Rong Tu
- Chaozhou Branch of Chemistry and Chemical Engineering Guangdong Laboratory, Chaozhou 521000, China
| | - Hai-Tao Feng
- AIE Research Center, College of Chemistry and Chemical Engineering, Baoji University of Arts and Sciences, Baoji 721013, China
| | - Honglian Dai
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology, Wuhan 430070, P. R. China
- Chaozhou Branch of Chemistry and Chemical Engineering Guangdong Laboratory, Chaozhou 521000, China
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Huang J, Ge S, Luo D, Du R, Wang Y, Liu W, Wang G, Yin T. The endothelium permeability after bioresorbable scaffolds implantation caused by the heterogeneous expression of tight junction proteins. Mater Today Bio 2022; 16:100410. [PMID: 36090609 PMCID: PMC9450163 DOI: 10.1016/j.mtbio.2022.100410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/18/2022]
Abstract
As one of the main functions of vascular endothelial cells, Vascular permeability is determined by four tight junction proteins (TJPs): Zonula Occludens-1 (ZO-1), Claudin-5, Occludin and Tricellulin. The barrier function of blood vessels will be reconstructed after they are damaged by endothelial mechanical injuries caused by vascular interventions. In this study, the effects of balloon expansion (transient mechanical injury) on four TJPs and vascular permeability were compared with those of poly-l-lactic acid bioresorbable scaffolds (BRSs) implantation (continuous mechanical stimulation). We found that BRSs do not affect vascular permeability, while the recovery of vascular barrier function was found to be only related to the mechanical injuries and repair of endothelium. Mechanical stimulation affects and accelerates the recovery process of vascular permeability with the heterogeneous expression levels of TJPs induced after BRSs implantation. Different TJPs have different sensitivity to different loyal mechanical stimuli. ZO-1 is more sensitive to shear stress and tension than to static pressure. Occludin is sensitive to static pressure and shear stress. Tricellulin is more sensitive to tension stretching. Compared with the other three TJPs, Claudin-5 can respond to mechanical stimulation, with relatively low sensitivity, though. This difference in sensitivity determines the heterogeneous expression of TJPs. Mechanical stimulation of different kinds and strengths can also cause different cell morphological changes and inflammatory reactions. As an important element affecting endothelial function, the mechanical factors emerging after BRSs implantation are worthy of more attention. The repair of vascular permeability is directly related to the type of vascular injuries, while BRSs implantation has little effect on vascular permeability. Transient and persistent mechanical stimulation is the main reason to influence the expression of TJPs. Heterogeneous expression of TJPs caused by their different sensitivity to the form of mechanical stimuli.
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InSilc Computational Tool for In Silico Optimization of Drug-Eluting Bioresorbable Vascular Scaffolds. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:5311208. [PMID: 36105243 PMCID: PMC9467806 DOI: 10.1155/2022/5311208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/12/2022] [Accepted: 08/17/2022] [Indexed: 11/17/2022]
Abstract
Stents made by different manufacturers must meet the requirements of standard in vitro mechanical tests performed under different physiological conditions in order to be validated. In addition to in vitro research, there is a need for in silico numerical simulations that can help during the stent prototyping phase. In silico simulations have the ability to give the same stent responses as well as the potential to reduce costs and time needed to carry out experimental tests. The goal of this paper is to show the achievements of the computational platform created as a result of the EU-funded project InSilc, used for numerical testing of most standard tests for validation of preproduction bioresorbable vascular scaffolds (BVSs). Within the platform, an ad hoc simulation protocol has been developed based on the finite element (FE) analysis program PAK and user interface software CAD Field and Solid. Two different designs of two different stents have been numerically simulated using this integrated tool, and the results have been demonstrated. The following standard tests have been performed: longitudinal tensile strength, local compression, kinking, and flex 1-3. Strut thickness and additional pocket holes (slots) in two different scaffolds have been used as representative parameters for comparing the mechanical characteristics of the stents (AB-BVS vs. AB-BVS-thinner and PLLA-prot vs. PLLA-plot-slot). The AB-BVS-thinner prototype shows better overall stress distribution than the AB-BVS, while the PLLA-prot shows better overall stress distribution in comparison to the PLLA-plot-slot. In all cases, the values of the maximum effective stresses are below 220 MPa—the value obtained by in vitro experiment. Despite the presented results, additional considerations should be included before the proposed software can be used as a validation tool for stent prototyping.
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Analysis of Causes and Results of Fetal Growth in Utero Caused by Genetic Factors Detected by Ultrasound. CONTRAST MEDIA & MOLECULAR IMAGING 2022; 2022:3703132. [PMID: 36105440 PMCID: PMC9452974 DOI: 10.1155/2022/3703132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 08/06/2022] [Accepted: 08/16/2022] [Indexed: 11/22/2022]
Abstract
In order to investigate the value of the ultrasonic monitoring of maternal and fetal vascular parameters, serum vitamin D, and placental growth factor (PLGF) in predicting fetal growth restriction (FGR), a method of ultrasonic detection of genetic factors causing fetal growth in utero was proposed. 125 pregnant women with FGR diagnosed in our hospital from June 2018 to June 2021 (the FGR group) and 125 pregnant women with a normal prenatal examination (the control group) were collected retrospectively. The systolic/diastolic blood flow ratio (S/D), pulsatile index (PI), and resistance index (RI) of the fetal umbilical artery (UA), middle cerebral artery (MCA), and maternal uterine artery (UtA) were monitored by ultrasound at 20 to 24 weeks of gestation, and the levels of serum vitamin D and PLGF were detected. The receiver operating characteristic curve (ROC curve) was used to evaluate the predictive value of FGR. The results showed that the S/D, PI, and RI of UA in the FGR group were higher than those in the control group, the areas under the curve (AUC) were 0.866, 0.817, and 0.849, and the sensitivity and specificity were (72.8%, 91.2%), (50.4%, 100%), and (72.8%, 91.2%), respectively. The S/D, PI, and RI of MCA were lower than those of the control group. The AUC was 0.882, 0.869, and 0.834, respectively; the sensitivity and specificity were (92.0%, 74.4%), (88.8%, 81.6%), and (90.4%, 72%), respectively. The S/D, PI, and RI of UtA were higher than those of the control group; the AUC was 0.768, 0.729, and 0.732; the sensitivity and specificity were (91.2%, 52%), (48%, 90.4%), and (48.8%, 90.4%), respectively. The serum levels of vitamin D and PLGF were lower than those of the control group (AUC 0.784 and 0.807), and the sensitivity and specificity were (54.4%, 91.2%) and (99.2%, 52%), respectively. It was concluded that the ultrasound monitoring of UA, MCA, and UtA in pregnant women in the middle of pregnancy and detection of serum vitamin D and PLGF levels had a certain predictive value for FGR. Moreover, the comprehensive evaluation could reduce the occurrence of FGR in high-risk pregnant women.
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11
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Lin S, Premaraj TS, Gamage PT, Dong P, Premaraj S, Gu L. Upper Airway Flow Dynamics in Obstructive Sleep Apnea Patients with Various Apnea-Hypopnea Index. Life (Basel) 2022; 12:1080. [PMID: 35888168 PMCID: PMC9318930 DOI: 10.3390/life12071080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/03/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND AND AIM This study evaluates the upper airway flow characteristics, anatomical features and analyzes their correlations with AHI in patients with varied degrees of OSA severity seeking for discernments of the underlying pathophysiological profile. MATERIALS AND METHODS Patient-specific computational fluid dynamics models were reconstructed from high-resolution cone-beam computed tomography images for 4 OSA patients classified as minimal, mild, moderate, and severe according to AHI. RESULTS The parameters, minimal cross-sectional area (MCA), and the pharyngeal airway volume did not show clear correlations with the OSA severity defined according to AHI. No correlations were found between the classically defined resistance of the airway in terms of pressure drop and AHI. The flow analysis further showed that the fluid mechanisms likely to cause airway collapse are associated with the degree of narrowing in the pharyngeal airway rather than AHI. Results also suggested that some patients classified as severe OSA according to the AHI can show less susceptibility to airway collapse than patients with relatively lower AHI values and vice versa. CONCLUSIONS The relative contribution of anatomical and non-anatomical causes to the OSA severity can significantly vary between patients. AHI alone is inadequate to be used as a marker of the pathophysiological profile of OSA. Combining airflow analysis with AHI in diagnosing OSA severity may provide additional details about the underlying pathophysiology, subsequently improving the individualized clinical outcomes.
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Affiliation(s)
- Shengmao Lin
- School of Civil Engineering and Architecture, Xiamen University of Technology, Xiamen 361024, China;
| | | | - Peshala T. Gamage
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA;
| | - Pengfei Dong
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA;
| | - Sundaralingam Premaraj
- College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, FL 33328, USA; (T.S.P.); (S.P.)
| | - Linxia Gu
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA;
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Capuana E, Lopresti F, Ceraulo M, La Carrubba V. Poly-l-Lactic Acid (PLLA)-Based Biomaterials for Regenerative Medicine: A Review on Processing and Applications. Polymers (Basel) 2022; 14:1153. [PMID: 35335484 PMCID: PMC8955974 DOI: 10.3390/polym14061153] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/02/2022] [Accepted: 03/09/2022] [Indexed: 02/06/2023] Open
Abstract
Synthetic biopolymers are effective cues to replace damaged tissue in the tissue engineering (TE) field, both for in vitro and in vivo application. Among them, poly-l-lactic acid (PLLA) has been highlighted as a biomaterial with tunable mechanical properties and biodegradability that allows for the fabrication of porous scaffolds with different micro/nanostructures via various approaches. In this review, we discuss the structure of PLLA, its main properties, and the most recent advances in overcoming its hydrophobic, synthetic nature, which limits biological signaling and protein absorption. With this aim, PLLA-based scaffolds can be exposed to surface modification or combined with other biomaterials, such as natural or synthetic polymers and bioceramics. Further, various fabrication technologies, such as phase separation, electrospinning, and 3D printing, of PLLA-based scaffolds are scrutinized along with the in vitro and in vivo applications employed in various tissue repair strategies. Overall, this review focuses on the properties and applications of PLLA in the TE field, finally affording an insight into future directions and challenges to address an effective improvement of scaffold properties.
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Affiliation(s)
- Elisa Capuana
- Department of Engineering, University of Palermo, RU INSTM, Viale delle Scienze, 90128 Palermo, Italy; (E.C.); (M.C.); (V.L.C.)
| | - Francesco Lopresti
- Department of Engineering, University of Palermo, RU INSTM, Viale delle Scienze, 90128 Palermo, Italy; (E.C.); (M.C.); (V.L.C.)
| | - Manuela Ceraulo
- Department of Engineering, University of Palermo, RU INSTM, Viale delle Scienze, 90128 Palermo, Italy; (E.C.); (M.C.); (V.L.C.)
| | - Vincenzo La Carrubba
- Department of Engineering, University of Palermo, RU INSTM, Viale delle Scienze, 90128 Palermo, Italy; (E.C.); (M.C.); (V.L.C.)
- ATeN Center, University of Palermo, Viale delle Scienze, 90128 Palermo, Italy
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13
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Milosevic M, Anic M, Nikolic D, Geroski V, Milicevic B, Kojic M, Filipovic N. Application of in silico Platform for the Development and Optimization of Fully Bioresorbable Vascular Scaffold Designs. FRONTIERS IN MEDICAL TECHNOLOGY 2021; 3:724062. [PMID: 35047953 PMCID: PMC8757700 DOI: 10.3389/fmedt.2021.724062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/08/2021] [Indexed: 11/29/2022] Open
Abstract
Bioresorbable vascular scaffolds (BVS), made either from polymers or from metals, are promising materials for treating coronary artery disease through the processes of percutaneous transluminal coronary angioplasty. Despite the opinion that bioresorbable polymers are more promising for coronary stents, their long-term advantages over metallic alloys have not yet been demonstrated. The development of new polymer-based BVS or optimization of the existing ones requires engineers to perform many very expensive mechanical tests to identify optimal structural geometry and material characteristics. in silico mechanical testing opens the possibility for a fast and low-cost process of analysis of all the mechanical characteristics and also provides the possibility to compare two or more competing designs. In this study, we used a recently introduced material model of poly-l-lactic acid (PLLA) fully bioresorbable vascular scaffold and recently empowered numerical InSilc platform to perform in silico mechanicals tests of two different stent designs with different material and geometrical characteristics. The result of inflation, radial compression, three-point bending, and two-plate crush tests shows that numerical procedures with true experimental constitutive relationships could provide reliable conclusions and a significant contribution to the optimization and design of bioresorbable polymer-based stents.
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Affiliation(s)
- Miljan Milosevic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Institute for Information Technologies, University of Kragujevac, Kragujevac, Serbia
- Faculty of Information Technologies, Belgrade Metropolitan University, Belgrade, Serbia
| | - Milos Anic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia
| | - Dalibor Nikolic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Institute for Information Technologies, University of Kragujevac, Kragujevac, Serbia
| | - Vladimir Geroski
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia
| | - Bogdan Milicevic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia
| | - Milos Kojic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX, United States
- Serbian Academy of Sciences and Arts, Belgrade, Serbia
| | - Nenad Filipovic
- Bioengineering Research and Development Center, BioIRC, Kragujevac, Serbia
- Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia
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14
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Wang W, Zhang B, Zhao L, Li M, Han Y, Wang L, Zhang Z, Li J, Zhou C, Liu L. Fabrication and properties of PLA/nano-HA composite scaffolds with balanced mechanical properties and biological functions for bone tissue engineering application. NANOTECHNOLOGY REVIEWS 2021. [DOI: 10.1515/ntrev-2021-0083] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Abstract
Repair of critical bone defects is a challenge in the orthopedic clinic. 3D printing is an advanced personalized manufacturing technology that can accurately shape internal structures and external contours. In this study, the composite scaffolds of polylactic acid (PLA) and nano-hydroxyapatite (n-HA) were manufactured by the fused deposition modeling (FDM) technique. Equal mass PLA and n-HA were uniformly mixed to simulate the organic and inorganic phases of natural bone. The suitability of the composite scaffolds was evaluated by material characterization, mechanical property, and in vitro biocompatibility, and the osteogenesis induction in vitro was further tested. Finally, the printed scaffold was implanted into the rabbit femoral defect model to evaluate the osteogenic ability in vivo. The results showed that the composite scaffold had sufficient mechanical strength, appropriate pore size, and biocompatibility. Most importantly, the osteogenic induction performance of the composite scaffold was significantly better than that of the pure PLA scaffold. In conclusion, the PLA/n-HA scaffold is a promising composite biomaterial for bone defect repair and has excellent clinical transformation potential.
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Affiliation(s)
- Wenzhao Wang
- Orthopedic Research Institute, Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University , Chengdu 610041 , China
| | - Boqing Zhang
- National Engineering Research Center for Biomaterials, Sichuan University , Chengdu 610064 , China
- College of Biomedical Engineering, Sichuan University , Chengdu 610064 , China
| | - Lihong Zhao
- Orthopedic Research Institute, Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University , Chengdu 610041 , China
| | - Mingxin Li
- Orthopedic Research Institute, Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University , Chengdu 610041 , China
| | - Yanlong Han
- Department of Orthopedics, The People’s Hospital of Xinjiang Uygur Autonomous Region , Urumqi 830001 , China
| | - Li Wang
- Department of Orthopedics, The People’s Hospital of Xinjiang Uygur Autonomous Region , Urumqi 830001 , China
| | - Zhengdong Zhang
- Orthopedic Research Institute, Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University , Chengdu 610041 , China
- Department of Orthopedics, The First Affiliated Hospital of Chengdu Medical College , Chengdu , Sichuan , China
| | - Jun Li
- Orthopedic Research Institute, Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University , Chengdu 610041 , China
| | - Changchun Zhou
- National Engineering Research Center for Biomaterials, Sichuan University , Chengdu 610064 , China
- College of Biomedical Engineering, Sichuan University , Chengdu 610064 , China
| | - Lei Liu
- Orthopedic Research Institute, Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University , Chengdu 610041 , China
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15
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Wang L, Jiao L, Pang S, Yan P, Wang X, Qiu T. The Development of Design and Manufacture Techniques for Bioresorbable Coronary Artery Stents. MICROMACHINES 2021; 12:mi12080990. [PMID: 34442612 PMCID: PMC8398368 DOI: 10.3390/mi12080990] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/18/2021] [Accepted: 08/18/2021] [Indexed: 02/02/2023]
Abstract
Coronary artery disease (CAD) is the leading killer of humans worldwide. Bioresorbable polymeric stents have attracted a great deal of interest because they can treat CAD without producing long-term complications. Bioresorbable polymeric stents (BMSs) have undergone a sustainable revolution in terms of material processing, mechanical performance, biodegradability and manufacture techniques. Biodegradable polymers and copolymers have been widely studied as potential material candidates for bioresorbable stents. It is a great challenge to find a reasonable balance between the mechanical properties and degradation behavior of bioresorbable polymeric stents. Surface modification and drug-coating methods are generally used to improve biocompatibility and drug loading performance, which are decisive factors for the safety and efficacy of bioresorbable stents. Traditional stent manufacture techniques include etching, micro-electro discharge machining, electroforming, die-casting and laser cutting. The rapid development of 3D printing has brought continuous innovation and the wide application of biodegradable materials, which provides a novel technique for the additive manufacture of bioresorbable stents. This review aims to describe the problems regarding and the achievements of biodegradable stents from their birth to the present and discuss potential difficulties and challenges in the future.
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Affiliation(s)
- Liang Wang
- School of Mechanical Engineering, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (L.W.); (S.P.)
| | - Li Jiao
- Key Laboratory of Fundamental Science for Advanced Machining Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (L.J.); (P.Y.); (X.W.)
| | - Shuoshuo Pang
- School of Mechanical Engineering, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (L.W.); (S.P.)
| | - Pei Yan
- Key Laboratory of Fundamental Science for Advanced Machining Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (L.J.); (P.Y.); (X.W.)
| | - Xibin Wang
- Key Laboratory of Fundamental Science for Advanced Machining Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (L.J.); (P.Y.); (X.W.)
| | - Tianyang Qiu
- Key Laboratory of Fundamental Science for Advanced Machining Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (L.J.); (P.Y.); (X.W.)
- Correspondence:
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