In silico modeling of structural and porosity properties of additive manufactured implants for regenerative medicine

Brünler, Ronny; Aibibu, Dilbar; Wöltje, Michael; Anthofer, Anna-Maria; Cherif, Chokri

doi:10.1016/j.msec.2017.03.105

Cited by 15 publications

(16 citation statements)

References 44 publications

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“…Clearly, the width of the fiber track depends on the fiber length used and usually ranges from 0.5 mm to 2 mm. With these fiber lengths, which can be estimated simulation-based, suitable pore sizes and porosities for regenerative medicine can be generated [41]. For the second process step, a piezo-controlled adhesive nozzle is actuated.…”

Section: Resultsmentioning

confidence: 99%

Design of Complexly Graded Structures inside Three-Dimensional Surface Models by Assigning Volumetric Structures

Brünler

Hausmann

Münchow

et al. 2019

Journal of Healthcare Engineering

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An innovative approach for designing complex structures from STL-datasets based on novel software for assigning volumetric data to surface models is reported. The software allows realizing unique complex structures using additive manufacturing technologies. Geometric data as obtained from imaging methods, computer-aided design, or reverse engineering that exist only in the form of surface data are converted into volumetric elements (voxels). Arbitrary machine data can be assigned to each voxel and thereby enable implementing different materials, material morphologies, colors, porosities, etc. within given geometries. The software features an easy-to-use graphical user interface and allows simple implementation of machine data libraries. To highlight the potential of the modular designed software, an extrusion-based process as well as a two-tier additive manufacturing approach for short fibers and binder process are combined to generate three-dimensional components with complex grading on the material and structural level from STL files.

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Section: Resultsmentioning

confidence: 99%

Design of Complexly Graded Structures inside Three-Dimensional Surface Models by Assigning Volumetric Structures

Brünler

Hausmann

Münchow

et al. 2019

Journal of Healthcare Engineering

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“…where P is the total porosity [%], m is the dry weight of the sample, V is the volume of the dry sample, r is the density of the material used [14]. When measuring the pore size, an optical microscope SIGETA MB 140 LED Mono was used to study the drugs in transmitted, reflected and mixed light.…”

Section: Influence Of the Structure Of Hydrogels Hydrogel Implants Onmentioning

confidence: 99%

Improving the Antitumor Effect of Doxorubicin in the Treatment of Eyeball and Orbital Tumors

Parfentievich¹,

Markovich²,

Mikhailivna³

2021

Advances in Precision Medicine Oncology

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Malignant tumors of the orbit are the main cause for 41–45.9% of orbital tumor, and they will threaten both the organ of vision and the life of the patient. In our opinion, improving the effectiveness of treatment of malignant tumors can be implemented in the following areas: a) immobilization of doxorubicin in synthetic polymeric materials, which will fill the tissue structures that were resected and reduce the percentage of tumor recurrence. b) the use of nanomaterials for the delivery of doxorubicin to tumor cells. To develop a hydrogel implant and nanoparticles, to study the diffusion kinetics of doxorubicin in a hydrogel implant and the ability of nanoparticles to transport doxorubicin. The developed gels based on acrylic acid (AAc) were obtained by radical polymerization of an aqueous solution of monomers (AAc and N, N-methylenebisacrylamide (MBA)) at a temperature of 70°C. Matrices based on polyvinyl formal (PVF) were obtained by treatment of polyvinyl alcohol (PVA) with formaldehyde in the presence of a strong acid. Experimental studies were performed on rabbits of the Chinchilla breed, weighing 2–3 kg, aged 5–6 months, which during the study were in the same conditions. We implanted the hybrid gel in the scleral sac; orbital tissue and in the ear tissue of rabbits: Evaluation of the response of soft tissues and bone structures to implant materials was carried out on the basis of analysis of changes in clinical and pathomorphological parameters was performed after 10, 30 and 60 days. Diffusion of doxorubicin was examined by using UV spectroscopy [spectrophotometer-fluorimeter DS-11 FX + (DeNovix, USA)], analyzing samples at regular intervals during the day at a temperature of 25° C. The concentration of active substances was determined by the normalized peak absorption of doxorubicin at 480 nm. The release kinetics of the antitumor drug doxorubicin were investigated by using a UV spectrometer “Specord M 40” (maximum absorption 480 nm). The developed hydrogel implant has good biocompatibility and germination of surrounding tissues in the structure of the implant, as well as the formation of a massive fibrous capsule around it. An important advantage of the implant is also the lack of its tendency to resorption. Moreover, the results showed that the diffusion kinetics of doxorubicin from a liquid-crosslinked hydrogel reaches a minimum therapeutic level within a few minutes, while in the case of a tightly crosslinked - after a few hours. It was also found that the liquid-crosslinked hydrogel adsorbs twice as much as the cytostatic - doxorubicin. The analysis of the research results approved that the size of the nanoparticles is the main factor for improving drug delevary and penetration. Thus, nanoparticles with a diameter of less than 200 nm can penetrate into cells and are not removed from the circulatory system by macrophages, thereby prolonging their circulation in the body. About 10 nm. The developed hybrid hydrogel compositions have high mechanical strength, porosity, which provides 100% penetration of doxorubicin into experimental animal tissues. It was found that the kinetics of diffusion of drugs from liquid-crosslinked hydrogel reaches a minimum therapeutic level within a few minutes, whereas in the case of densely crosslinked hydrogel diffusion begins with a delay of several hours and the amount of drug released at equilibrium reaches much lower values (20–25%). The obtained preliminary experimental results allow us to conclude that our developed pathways for the delivery of drugs, in particular, doxorubicin to tumor cells will increase the effectiveness of antitumor therapy.

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“…During the process, fibers, which are not exposed to TFA serve as support structure and thus allow the realizing of overhangs, undercuts or cavities, similar to powder printing or SLS. The structures provide an interconnected pore network where the pore size is determined by the fiber properties (length and diameter) and can be precisely defined by modeling and simulation using the GeoDict software (Math2Market GmbH, Kaiserslautern, Germany) as shown in Figure 1 and explained in details in [50,51]. For all fiber-based 3D scaffolds (Silk, Silk-HA/β-TCP, Silk-PDGF and Silk-HA/β-TCP-PDGF) the same model was calculated and used for additive manufacturing by FAM.…”

Section: Simulation-based Scaffold Design and Additive Manufacturingmentioning

confidence: 99%

Functionalization of Silk Fibers by PDGF and Bioceramics for Bone Tissue Regeneration

et al. 2019

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Bone regeneration is a complex, well-organized physiological process of bone formation observed during normal fracture healing and involved in continuous remodeling throughout adult life. An ideal medical device for bone regeneration requires interconnected pores within the device to allow for penetration of blood vessels and cells, enabling material biodegradation and bone ingrowth. Additional mandatory characteristics include an excellent resorption rate, a 3D structure similar to natural bone, biocompatibility, and customizability to multiple patient-specific geometries combined with adequate mechanical strength. Therefore, endless silk fibers were spun from native silk solution isolated from silkworm larvae and functionalized with osteoconductive bioceramic materials. In addition, transgenic silkworms were generated to functionalize silk proteins with human platelet-derived growth factor (hPDGF). Both, PDGF-silk and bioceramic modified silk were then assembled into 3D textile implants using an additive manufacturing approach. Textile implants were characterized in terms of porosity, compressive strength, and cyclic load. In addition, osteogenic differentiation of mesenchymal stem cells was evaluated. Silk fiber-based 3D textile implants showed good cytocompatibility and stem cells cultured on bioceramic material functionalized silk implants were differentiating into bone cells. Thus, functionalized 3D interconnected porous textile scaffolds were shown to be promising biomaterials for bone regeneration.

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In silico modeling of structural and porosity properties of additive manufactured implants for regenerative medicine

Cited by 15 publications

References 44 publications

Design of Complexly Graded Structures inside Three-Dimensional Surface Models by Assigning Volumetric Structures

Design of Complexly Graded Structures inside Three-Dimensional Surface Models by Assigning Volumetric Structures

Improving the Antitumor Effect of Doxorubicin in the Treatment of Eyeball and Orbital Tumors

Functionalization of Silk Fibers by PDGF and Bioceramics for Bone Tissue Regeneration

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