Bio-Medical Materials and Engineering - Volume 34, issue 4

Authors: de Guzman, Roche C. | Meer, Allison S. | Mathews, Aidan A. | Israel, Atara R. | Moses, Michael T. | Sams, Clarence M. | Deegan, Daniel B.

Article Type: Research Article

Abstract: BACKGROUND: Fibrous capsules (Fb) in response to cardiovascular implantable electronic devices (CIEDs), including a pacemaker (P) system, can produce patient discomfort and difficulties in revision surgery due partially to their increased compressive strength, previously linked to elevated tissue fibers. OBJECTIVE: A preliminary study to quantify structural proteins, determine if biologic extracellular matrix-enveloped CIEDs (PECM) caused differential Fb properties, and to implement a realistic mechanical model. METHODS: Retrieved Fb (-P and -PECM) from minipigs were subjected to biomechanical (shear oscillation and uniaxial compression) and histological (collagen I and elastin) analyses. RESULTS: Fb-PECM showed significant decreases …compared to Fb-P in: low strain-loss modulus (390 vs. 541 Pa) across angular frequencies, high strain-compressive elastic modulus (1043 vs. 2042 kPa), and elastic fiber content (1.92 vs. 3.15 μg/mg tissue). Decreases in elastin were particularly noted closer to the implant’s surface (Fb-PECM = 71% vs. Fb-P = 143% relative to dermal elastin at mid-tangential sections) and verified with a solid mechanics hyperelasticity with direction-dependent fiber viscoelasticity compression simulation (r 2 ≥ 98.9%). CONCLUSIONS: The biologic envelope composed of decellularized porcine small intestine submucosa ECM for CIEDs promoted fibrous tissues with less elastic fibers. Novel compression modeling analyses directly correlated this singular reduction to more desirable subcutaneous tissue mechanics. Show more

Keywords: Minipig study, cardiovascular implantable electronic devices, pacemaker, decellularized tissue ECM, biologic envelope, foreign body reaction, fibrous tissue encapsulation, compression biomechanics, oscillation rheology, elastin and elastic fibers, 3D distribution, COMSOL multiphysics hyperelastic simulation

DOI: 10.3233/BME-221488

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 4, pp. 289-304, 2023

Authors: Toyohara, Ryota | Hiramukai, Takahiro | Kurosawa, Daisuke | Hammer, Niels | Ohashi, Toshiro

Article Type: Research Article

Abstract: BACKGROUND: Pain related to the sacroiliac joint (SIJ) accounts for low back pain in 15%–30% of patients. One of the most common treatment options is the use of pelvic belts. Various types of pelvic belts exist; however, the mechanisms underlying treatment and their effectiveness remain unclear to date. OBJECTIVE: To analyze stress distribution in the pelvis when a pelvic rubber belt or a padded pelvic belt is applied, to assess the effectiveness of treatment from a numerical biomechanical perspective. METHODS: The pressure distribution at the pelvic belts was measured using a device and subsequently modeled with …the finite element method of a pelvis with soft tissues. The stress environment when wearing a pelvic belt in a double-leg stance was simulated. RESULTS: With the application of pelvic belts, the innominate bone rotated outward, which was termed an out-flare. This caused the SIJ to compress and cause reduction in sacrotuberous, sacrospinous, interosseous, and posterior sacroiliac ligament loading. Padded pelvic belts decreased the SIJ displacement to a greater extent than in pelvic rubber belts. CONCLUSION: Pelvic belts aid in compressing the SIJ and reduce its mobility. Show more

Keywords: Finite element analysis, low back pain, numerical analysis, pelvic belt, sacroiliac joint dysfunction

DOI: 10.3233/BME-221490

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 4, pp. 305-318, 2023

Authors: Mu, Junsheng | Zhang, Zichang | Zhou, Fan | Zheng, Jianwei | Bo, Ping | You, Bin

Article Type: Research Article

Abstract: BACKGROUND: Myocardial infarction is a serious clinical disease with high mortality and poor prognosis. Cardiomyocytes (CMs) have limited regeneration abilities after ischemic injury. Their growth and differentiation can be enhanced by contact co-culture with stem cells. OBJECTIVE: The aim was to study the contact co-culture of Dil-labeled bone marrow mesenchymal stem cells (BMSCs) and CMs for inducing differentiation of CMs from stem cells for treating myocardial infarction. METHODS: After contact co-culture, the differentiation of BMSCs into CMs was analyzed qualitatively by detecting myocardial markers (cardiac troponin T and α-smooth muscle actin) using immunofluorescence and quantitatively using …flow cytometry. To examine the mechanism, possible gap junctions between BMSCs and CMs were analyzed by detecting gap junction protein connexin 43 (C×43) expression in BMSCs using immunofluorescence. The functionality of gap junctions was analyzed using dye transfer experiments. RESULTS: The results revealed that BMSCs in contact with CMs exhibited myocardial markers and a significant increase in differentiation rate (P < 0.05); they also proved the existence and function of gap junctions between BMSCs and CMs. CONCLUSIONS: It was shown that contact co-culture can induce Dil-labeled BMSCs to differentiate into CM-like cells and examined the principle of gap junction-mediated signaling pathways involved in inducing stem cells to differentiate into cardiomyocytes. Show more

Keywords: Stem cell therapy, bone marrow mesenchymal stem cells, cardiomyocytes, contact co-culture, DiI labeling in vitro

DOI: 10.3233/BME-221429

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 4, pp. 319-330, 2023

Authors: Jiménez-Gastélum, German | Ramos-Payán, Rosalío | López-Gutierrez, Jorge | Ayala-Ham, Alfredo | Silva-Benítez, Erika | Bermúdez, Mercedes | Romero-Quintana, José Geovanni | Sanchez-Schmitz, Guzman | Aguilar-Medina, Maribel

Article Type: Research Article

Abstract: BACKGROUND: The necessity to manufacture scaffolds with superior capabilities of biocompatibility and biodegradability has led to the production of extracellular matrix (ECM) scaffolds. Among their advantages, they allow better cell colonization, which enables its successful integration into the hosted tissue, surrounding the area to be repaired and their formulations facilitate placing it into irregular shapes. The ECM from porcine urinary bladder (pUBM) comprises proteins, proteoglycans and glycosaminoglycans which provide support and enable signals to the cells. These properties make it an excellent option to produce hydrogels that can be used in regenerative medicine. OBJECTIVE: The goal of this …study was to assess the biocompatibility of an ECM hydrogel derived from the porcine urinary bladder (pUBMh) in vitro using fibroblasts, macrophages, and adipose-derived mesenchymal stem cells (AD-MCSs), as well as biocompatibility in vivo using Wistar rats. METHODS: Effects upon cells proliferation/viability was measured using MTT assay, cytotoxic effects were analyzed by quantifying lactate dehydrogenase release and the Live/Dead Cell Imaging assay. Macrophage activation was assessed by quantification of IL-6, IL-10, IL-12p70, MCP-1, and TNF-α using a microsphere-based cytometric bead array. For in vivo analysis, Wistar rats were inoculated into the dorsal sub-dermis with pUBMh. The specimens were sacrificed at 24 h after inoculation for histological study. RESULTS: The pUBMh obtained showed good consistency and absence of cell debris. The biocompatibility tests in vitro revealed that the pUBMh promoted cell proliferation and it is not cytotoxic on the three tested cell lines and induces the production of pro-inflammatory cytokines on macrophages, mainly TNF-α and MCP-1. In vivo , pUBMh exhibited fibroblast-like cell recruitment, without tissue damage or inflammation. CONCLUSION: The results show that pUBMh allows cell proliferation without cytotoxic effects and can be considered an excellent biomaterial for tissue engineering. Show more

Keywords: Urinary bladder extracellular matrix, hydrogel, biological scaffolds, biocompatibility

DOI: 10.3233/BME-221450

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 4, pp. 331-344, 2023

Authors: Qu, Siwei | Ma, Ning | Wang, Weixin | Chen, Sen | Wu, Qi | Li, Yangqun | Yang, Zhe

Article Type: Research Article

Abstract: BACKGROUND: Human adipose-derived stem cells have been identified as a promising candidate for cell-assisted therapy to improve graft survival. OBJECTIVE: To objective of the study was to add human adipose-derived stem cells into filling materials. METHODS: The filling materials were prepared and divided into 6 groups: fat particles with phosphate buffer saline or human adipose-derived stem cells; acellular dermal matrix particles with phosphate buffer saline or human adipose-derived stem cells; mixture of fat particles and acellular dermal matrix particles with phosphate buffer saline or human adipose-derived stem cells. The survival rate, vascular density and histological at …2, 6 and 12 weeks were investigated. RESULTS: Human adipose-derived stem cells significantly improved survival rate in each group at 6 and 12 weeks, and it significantly increased the vascular density in the fat particles and porcine acellular dermal matrix combined group and porcine acellular dermal matrix group at three time points, but human adipose-derived stem cells did not have a significant effect in the fat particles group. CONCLUSION: Human adipose-derived stem cells as assisted cells added into filling material can improve survival rate and vascular density in rats. Show more

Keywords: Human adipose-derived stem cells, porcine acellular dermal matrix, filling material

DOI: 10.3233/BME-222503

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 4, pp. 345-355, 2023

Authors: Ortiz-Magdaleno, Marine | Sánchez-Vargas, Luis | Gardea-Contreras, Delia | Campos-Ibarra, Verónica | Pozos-Guillén, Amaury | Márquez-Preciado, Raúl

Article Type: Research Article

Abstract: BACKGROUND: Acrylic resins used in dental and biomedical applications do not have antimicrobial properties, their surface is susceptible to colonization of microorganisms. OBJECTIVE: 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. METHODS: 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). RESULTS: 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. CONCLUSION: AgNPs incorporated into PMMA decreased the growth and maturation of S. aureus biofilm. Show more

Keywords: Polymethyl methacrylate, silver nanoparticles, bioreactor system, Staphylococcus aureus , biofilm

DOI: 10.3233/BME-222513

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 4, pp. 357-373, 2023

Authors: Hu, Xu-Qi | Lu, Hui-Gen | Zhou, Xiao | Hu, Min-Jie | Pan, Xue-Kang | Chen, Bao | Yu, Ye-Feng

Article Type: Research Article

Abstract: BACKGROUND: There are conflicting results for robot-assisted (RA) pedicle screw fixation compared with freehand (FH) pedicle screw fixation. OBJECTIVE: This study was designed to retrospectively compare the accuracy and efficacy of RA percutaneous pedicle screw fixation and traditional freehand FH pedicle screw fixation in the treatment of thoracolumbar fractures. METHODS: A total of 26 cases were assigned to the RA group, and 24 cases were assigned to the FH group. The operation time, bleeding volume, and visual analog scale (VAS) score 1 day after the operation, and the anterior/posterior (A/P) vertebral height ratio of the injured …vertebrae at 3 days and at internal fixation removal 1 year after the operation were compared between the two groups. Pedicle screw position accuracy was assessed according to Gertzbein criteria. RESULTS: The operation times of the RA group and FH group were 138.69 ± 32.67 minutes and 103.67 ± 14.53 minutes, respectively, and the difference was statistically significant. The intraoperative blood loss was 49.23 ± 22.56 ml in the RA group and 78.33 ± 23.90 ml in the FH group, and the difference was statistically significant. There was a significant difference in the A/P vertebral height ratio of the injured vertebrae 3 days after the operation compared with before the operation in both groups (P < 0.05). There was a significant difference in the A/P vertebral height ratio of the injured vertebrae 3 days after the operation compared with that at fixation removal in both groups (P < 0.05). CONCLUSION: The application of RA orthopedic treatment for thoracolumbar fractures can achieve good fracture reduction. Show more

Keywords: Orthopedic robot, thoracolumbar fractures, pedicle screw

DOI: 10.3233/BME-222521

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 4, pp. 375-383, 2023