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Three-dimensional printing (3DP) has gained popularity among scientists and researchers in every field due to its potential to drastically reduce energy costs for the production of customised products by utilising less energy-intensive machines as well as minimising material waste. The 3D printing technology is an additive manufacturing approach that uses material layer-by-layer fabrication to produce the digitally specified 3D model. The use of 3D printing technology in the pharmaceutical sector has the potential to revolutionise research and development by providing a quick and easy means to manufacture personalised one-off batches, each with unique dosages, distinct substances, shapes, and sizes, as well as variable release rates. This overview addresses the concept of 3D printing, its evolution, and its operation, as well as the most popular types of 3D printing processes utilised in the health care industry. It also discusses the application of these cutting-edge technologies to the pharmaceutical industry, advancements in various medical fields and medical equipment, 3D bioprinting, the most recent initiatives to combat COVID-19, regulatory frameworks, and the major challenges that this technology currently faces. In addition, we attempt to provide some futuristic approaches to 3DP applications.
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Dental autotransplantation is an effective alternative to conventional dental treatment, and it involves removing a tooth and repositioning it in a new position within the same patient. Although this procedure might pose more intraoperative challenges, it provides a great solution for replacing missing teeth or aiding difficult eruption in young patients. This prospective method is also advocated as a use of treatment for unrestorable teeth. The success rates of autotransplantation cases with and without replicas were compared in a retrospective analysis of the data. By reducing donor tooth manipulation and ensuring a proper fit and positioning in the recipient socket, replicas significantly increased success rates of the procedure. CBCT scans were used to collect data. Data exported to the Mimics system were then processed in order to achieve a model of the donor tooth. Additive manufacturing technology was used to create the replicas. Specialized biocompatible material was used. Details of the replantation site and the donor tooth requirements were described, as well as the step-by-step surgical technique. For the best results, variables, like patient selection, surgical technique, and long-term monitoring, were found to be essential. The study highlights the significance of dental professionals and biomedical engineering staff working together to develop standard operating procedures and achieve predictable outcomes in autotransplantation procedures. The results suggest that 3D printed replicas could be a useful tool for improving the effectiveness and success of dental autotransplantation.
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Purpose: The study's starting point is to find a low-cost and best-fit solution for comfortable movement for a recreational runner with knee pain using an orthopedic device. It is a case study. The research aims to apply digitization, CAD/CAM tools, and 3D printing to create an individual 3D running insole. The objective is to incorporate flexible shape optimization would provide comfort reductions in foot plantar pressures in one subject with knee pain while running. The test hypothesis was if it is possible to make it from one material. For this purpose, we created a new digital workflow based on the Decision Tree method and analyzed pain and comfort scores during user testing of prototypes. Patient and Methods: The input data were obtained during a professional examination by a specialist doctor in the orthopedic outpatient clinic in the motion laboratory (DIERS 4D Motion Lab, Germany) with the output of data on the proband's complex movement stereotype. Surface and volumetric data were obtained in the biomedical laboratory with the 3D scanner. We modified the digital 3D foot models in 3D mesh software, developed the design in SW Gensole (Gyrobot, UK), and finally incorporated the internal structure and the surface layer of the insole data of the knowledge from the medical examination, comfort analyses, and scientific studies findings. Results: Four complete 3D-printed prototypes (n=4) with differences in density and correction elements were designed. All of them were fabricated on a 3D printer (Prusa i3 MK3S, Czech Republic) with flexible TPU material suitable for skin contact. The Participant tested each of them five times in the field during a workout and final insoles three months on the routine training. Conclusion: A novel workflow was created for designing, producing, and testing full 3D-printed insoles. The product is fit for immediate use.
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The goal of this review is to map the current state of biodegradable materials that are used in tissue engineering for a variety of applications. At the beginning, the paper briefly identifies typical clinical indications in orthopedics for the use of biodegradable implants. Subsequently, the most frequent groups of biodegradable materials are identified, classified, and analyzed. To this end, a bibliometric analysis was applied to evaluate the evolution of the scientific literature in selected topics of the subject. The special focus of this study is on polymeric biodegradable materials that have been widely used for tissue engineering and regenerative medicine. Moreover, to outline current research trends and future research directions in this area, selected smart biodegradable materials are characterized, categorized, and discussed. Finally, pertinent conclusions regarding the applicability of biodegradable materials are drawn and recommendations for future research are suggested to drive this line of research forward.
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Sternal dehiscence is an important complication that increases mortality and morbidity in cardiac surgery. Titanium plates have been used to reconstruct the chest wall for a long time. However, with the rise of 3D printing technology, a more sophisticated method, is making a breakthrough. Custom-made 3D-printed titanium prostheses are increasingly used in chest wall reconstruction because they allow almost perfect fitting to the patient's chest wall and lead to good functional and cosmetic results. This report presents a complex anterior chest wall reconstruction using a custom-made titanium 3D-printed implant in a patient with a sternal dehiscence after coronary artery bypass surgery. At first, reconstruction of the sternum was performed using conventional methods, which failed to give adequate results. Finally, a 3D-printed titanium custom-made prosthesis was used for the first time in our center. On the short- and mid-term follow up, good functional results were achieved. In conclusion, this method is suitable for sternal reconstruction after complications in the healing process of median sternotomy wounds in cardiac surgery, especially where other methods do not provide satisfactory results.
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Procedimientos Quirúrgicos Cardíacos , Titanio , Humanos , Esternón/cirugía , Prótesis e Implantes , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Impresión Tridimensional , Dehiscencia de la Herida Operatoria/etiología , Dehiscencia de la Herida Operatoria/cirugíaRESUMEN
This case study describes the use of additive manufacturing technology combining a biodegradable polymer material, polycaprolactone (PCL), and innovative procedures for creating superficial wound dressing, a scaffold in the therapy of extensive contaminated skin defects caused by a traumatic injury. Chronic and contaminated wounds represent a clinical problem and require intensive wound care. The application of a temporary scaffold-facilitated bridging of the wound edges resulted in faster tissue regeneration and a shorter defect closure time, compared to other conservative and surgical methods used in therapy of chronic wounds. Although this procedure has proven to be an optimal alternative to autologous transplants, further studies with a larger number of patients would be beneficial.
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Prospective observational study. To evaluate patient-reported outcomes after navigation-guided minimally invasive hybrid lumbar interbody fusion (nMIS-HLIF) for decompression and fusion in degenerative spondylolisthesis (Meyerding grade I-II). Posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) are well-known standard procedures for lumbar spinal fusion. nMIS-HLIF is a navigation-guided combined percutaneous and open procedure that combines the advantages of PLIF and TLIF procedures for the preparation of a single-port endoscopic approach. 33 patients underwent nMIS-HLIF. Core outcome measure index (COMI), oswestry disability index (ODI), numeric rating scale (NRS) back, NRS leg, and short form health-36 (SF-36) were collected preoperatively and at follow-up of 6 weeks, 3 months, 6 months, and 1 year. The impact of body mass index (BMI) was also analyzed. Computed tomography reconstruction was used to assess realignment and verify fused facet joints and vertebral bodies at the 1-year follow-up. 28 (85%) completed the 1-year follow-up. The median BMI was 27.6 kg/m2, age 69 yrs. The mean reduction in listhesis was 8.4% (Pâ <â .01). BMI was negatively correlated with listhesis reduction (Pâ =â .032). The improvements in the NRS back, NRS leg, ODI, and COMI scores were significant at all times (Pâ <â .001-Pâ <â .01). The SF-36 parameters of bodily pain, physical functioning, physical component summary, role functioning/physical functioning, and social functioning improved (Pâ <â .003). The complication rate was 15.2% (nâ =â 5), with durotomy (nâ =â 3) being the most frequent. To reduce the complication rate and allow transitioning to a fully endoscopic approach, expandable devices have been developed. The outcomes of nMIS-HLIF are comparable to the current standard open and minimally invasive techniques. A high BMI hinders this reduction. The nMIS-HLIF procedure is appropriate for learning minimally invasive dorsal lumbar stabilization. The presented modifications will enable single-port endoscopic lumbar stabilization in the future.
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Fusión Vertebral , Espondilolistesis , Anciano , Humanos , Tornillos Óseos , Hueso Cortical/cirugía , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Medición de Resultados Informados por el Paciente , Estudios Retrospectivos , Fusión Vertebral/métodos , Espondilolistesis/cirugía , Resultado del TratamientoRESUMEN
One trend in tissue engineering and regenerative medicine is the development of degradable composite polymers. The aim of this study was the comprehensive analysis of Polylactic acid (PLA)/Polyhydroxybutyrate (PHB) + Hydroxyapatite (HA)/Tricalcium phosphate (TCP) material from filament production to mechanical testing of samples with different infills and the production of an implant replacement for an intervertebral disc. Filament Maker-Composer 450 (3devo; Netherlands) was used to produce filaments. Experimental samples and the implant for the intervertebral disc were made using FDM technology using a DeltiQ2 3D printer (Trilab, Czech Republic). Mechanical testing of experimental samples was performed on an Inspekt TABLE 5 kN (Hegewald & Peschke, Nossen, Germany). Microscopic analysis, cytotoxicity test, and filament diameter analysis using descriptive statistics were also part of the focus. The results of the analysis of the diameter of the filament show that the filament meets the prescribed standard. The cytotoxicity test for PLA/PHB + HA/TCP material showed no toxicity. Microscopic analysis showed an even distribution of the ceramic component in the composite polymer. Mechanical testing showed a reduction in mechanical properties with 75% and 50% of the filling of experimental samples. All experimental samples subjected to mechanical testing showed higher tensile and compressive strength values compared to the values of the mechanical properties of vertebral trabecular bones, as reported in the literature. It can therefore be concluded that the material under investigation, PLA/PHB + HA/TCP appears to be a suitable candidate for hard tissue replacement.
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The present study deals with preparing a polymer-based material with incorporated ceramics and monitoring changes in properties after in vitro natural degradation. The developed material is a mixture of polymers of polylactic acid and polyhydroxybutyrate in a ratio of 85:15. Ceramic was incorporated into the prepared material, namely 10% hydroxyapatite and 10% tricalcium phosphate of the total volume. The material was processed into a filament form, and types of solid and porous samples were prepared using additive technology. These samples were immersed in three different solutions: physiological solution, phosphate-buffered saline, and Hanks' solution. Under constant laboratory conditions, changes in solution pH, material absorption, weight loss, changes in mechanical properties, and surface morphology were monitored for 170 days. The average value of the absorption of the solid sample was 7.07%, and the absorption of the porous samples was recorded at 8.33%, which means a difference of 1.26%. The least change in pH from the reference value of 7.4 was noted with the phosphate-buffered saline solution. Computed tomography was used to determine the cross-section of the samples. The obtained data were used to calculate the mechanical properties of materials after degradation. The elasticity modulus for both the full and porous samples degraded in Hanks' solution (524.53 ± 13.4 MPa) has the smallest deviation from the non-degraded reference sample (536.21 ± 22.69 MPa).
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Dental replacements are placed between the abutment teeth. The exceptions are two-unit bridges, as they are supported by a single tooth prepared only on one side of the missing tooth. The presented study deals with an analysis of a pressure force action on two-unit bridges placed in the frontal part (20 samples), where the pressure action is lower, and in the distal part (20 samples), where the pressure action is higher. A CAD program by 3Shape was used for digital designing with two different gap settings, 10 µm (20 samples) and 30 µm (20 samples). Two-unit bridges were attached to the prepared tooth using two types of dental cement (20/20 samples), which were selected for their physical and bioactive properties. All two-unit bridges (a total of 80 samples) were fabricated from CoCr alloys on Mlab cusing R by applying the Selective Laser Melting (SLM) technology. Mechanical testing was performed using the Inspekt5 table blue. The obtained data were used to verify the hypotheses-a difference between both types of cement (A ≠ B), a difference between the frontal and distal two-unit bridges (F ≠ D) and a difference between the gap sizes (10 ≠ 30). To confirm the given theories, data were statistically evaluated using the F-test and subsequent t-tests. The resulting p-value was compared with the level of significance (α = 0.05). A statistical evaluation revealed a significant difference between the compared groups; however, no explicit correlation between the individual groups of specimens was identified.
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The complex process of placental implantation and development affects trophoblast progenitors and uterine cells through the regulation of transcription factors, cytokines, adhesion receptors and their ligands. Differentiation of trophoblast precursors in the trophectoderm of early ontogenesis, caused by the transcription factors, such as CDX2, TEAD4, Eomes and GATA3, leads to the formation of cytotrophoblast and syncytiotrophoblast populations. The molecular mechanisms involved in placental formation inside the human body along with the specification and differentiation of trophoblast cell lines are, mostly due to the lack of suitable cell models, not sufficiently elucidated. This review is an evaluation of current technologies, which are used to study the behavior of human trophoblasts and other placental cells, as well as their ability to represent physiological conditions both in vivo and in vitro. An in vitro 3D model with a characteristic phenotype is of great benefit for the study of placental physiology. At the same time, it provides great support for future modeling of placental disease.
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Biopolymers have been the most frequently studied class of materials due to their biodegradability, renewability, and sustainability. The main aim of the presented study was to evaluate degradability of the polymer material blend which was immersed in different solutions. The present study included the production of three different mixtures of polylactic acid and polyhydroxybutyrate, each with a different content of triacetin, which was used as a plasticiser. Applying 3D printing technology, two types of cylindrical specimen were produced, i.e., a solid and a porous specimen, and subjected to in vitro natural degradation. The biodegradation process ran for 195 days in three different solutions (saline, phosphate-buffered saline (PBS), and Hank's solution) in stable conditions of 37 °C and a pH of 7.4, while the specimens were kept in an orbital motion to simulate the flow of fluids. The goal was to identify the effects of a solution type, specimen shape and material composition on the biodegradation of the materials. The monitored parameters included changes in the solution quantity absorbed by the specimens; morphological changes in the specimen structure; and mechanical properties. They were measured by compressive testing using the Inspekt5 Table Blue testing device. The experiment revealed that specimen porosity affected the absorption of the solutions. The non-triacetin materials exhibited a higher mechanical resistance to compression than the materials containing a plasticiser. The final result of the experiment indicated that the plasticiser-free specimens exhibited higher values of solution absorption, no formation of block cracks or bubbles, and the pH values of the solutions in which these materials were immersed remained neutral for the entire experiment duration; furthermore, these materials did not reduce pH values down to the alkaline range, as was the case with the solutions with the plasticiser-containing materials. Generally, in applications where high mechanical resistance, earlier degradation, and more stable conditions are required, the use of non-plasticiser materials is recommended.
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PURPOSE: To identify the morphological patterns of suprascapular notch stenosis. METHODS: Suprascapular notch space capacity was assessed by morphometric analysis of 333 dry scapulae. Suprascapular notch parameters-superior transverse distance, middle width, depth, medial border length and lateral border length-were measured. The probable suprascapular notch stenosis was referenced by (1) comparing each obtained parameter measurement to the range of the suprascapular nerve diameter, and (2) quantifying the reduced parameters. Finally, the morphological pattern was determined based on the collective reduction of the parameters and their alignments. RESULTS: Five types of suprascapular notch based on depth to superior transverse distance ratio were identified and assessed. Type-I showed low incidence of stenosis (6/333) and low frequency within type (6/28) with potential risk of horizontal compression. Type-II showed relatively low incidence of stenosis (9/333) and low frequency within type (9/50) with undetermined pattern. Type-III showed relatively higher incidence of stenosis (47/333) but low frequency within type (47/158) with potential risk of vertical compression. Type-IV (foramen) showed low incidence of stenosis (6/333) and relatively lower frequency within type (6/26) with potential risk of encircled compression. Finally, type-V (discrete) showed relatively high incidence of stenosis (40/333) and high frequency within type (40/71) with potential risk of vertical compression. The suprascapular notch was found to be stenosed beyond its capacity to accommodate the suprascapular nerve in 49/333. Type-V is at most risk followed by Type-III. CONCLUSIONS: Suprascapular notch stenosis takes three morphological patterns: horizontal, vertical or mixed. An osteoplasty of suprascapular notch margins may be required beside the common surgical approach of the superior transverse scapular ligamentectomy.
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Síndromes de Compresión Nerviosa/epidemiología , Escápula/patología , Cadáver , Cementoplastia/estadística & datos numéricos , Constricción Patológica/epidemiología , Constricción Patológica/patología , Humanos , Incidencia , Síndromes de Compresión Nerviosa/cirugía , Procedimientos de Cirugía Plástica/estadística & datos numéricos , Escápula/cirugía , Hombro/cirugíaRESUMEN
Human emotion recognition has been a major field of research in the last decades owing to its noteworthy academic and industrial applications. However, most of the state-of-the-art methods identified emotions after analyzing facial images. Emotion recognition using electroencephalogram (EEG) signals has got less attention. However, the advantage of using EEG signals is that it can capture real emotion. However, very few EEG signals databases are publicly available for affective computing. In this work, we present a database consisting of EEG signals of 44 volunteers. Twenty-three out of forty-four are females. A 32 channels CLARITY EEG traveler sensor is used to record four emotional states namely, happy, fear, sad, and neutral of subjects by showing 12 videos. So, 3 video files are devoted to each emotion. Participants are mapped with the emotion that they had felt after watching each video. The recorded EEG signals are considered further to classify four types of emotions based on discrete wavelet transform and extreme learning machine (ELM) for reporting the initial benchmark classification performance. The ELM algorithm is used for channel selection followed by subband selection. The proposed method performs the best when features are captured from the gamma subband of the FP1-F7 channel with 94.72% accuracy. The presented database would be available to the researchers for affective recognition applications.
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Algoritmos , Electroencefalografía/métodos , Emociones/clasificación , Benchmarking , Encéfalo/anatomía & histología , Encéfalo/fisiología , Ondas Encefálicas/fisiología , Biología Computacional , Bases de Datos Factuales , Electroencefalografía/estadística & datos numéricos , Emociones/fisiología , Femenino , Humanos , Aprendizaje Automático , Masculino , Conceptos Matemáticos , Redes Neurales de la Computación , Estimulación Luminosa , Grabación en VideoRESUMEN
In recent years, the number of cervical interventions has increased. The stress shielding effect is a serious complication in cervical spine interventions. Topological optimization is based on finite element method structural analysis and numerical simulations. The generated design of cervical implants is made from Ti6Al4V powder by selective laser melting while the optimized cage is numerically tested for compressive axial loading and the results are compared with experimental measurement. Additive manufacturing technologies and new software possibilities in the field of structural analysis, which use the finite element method tools, help to execute implant topological optimization that is useful for clinical practice. The inner structures of the implant would be impossible to make by conventional manufacturing technologies. The resulting implant design, after modification, must fulfill strict application criteria for the area of cervical spine with respect to its material and biomechanical properties. The aim of this work was to alter the mechanical properties of the cervical intervertebral cage to address the clinical concern of the stress shielding effect by topological optimization. A methodology of cervical implant compressive axial loading numerical simulation was created, and subsequent experimental testing was done to obtain real material properties after a selective laser melting process. The weight of the optimized implant was reduced by 28.92 %. Results of the experimental testing and numerical simulation of topologically optimized design showed 10-times lower stiffness compared to the solid cage design, and the real yield strength of the optimized structure is 843.8â¯MPa based on experimental results.
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Vértebras Cervicales/cirugía , Simulación por Computador , Fijadores Internos , Diseño de Prótesis/métodos , Fusión Vertebral/instrumentación , Aleaciones/química , Discectomía , Módulo de Elasticidad , Análisis de Elementos Finitos , Humanos , Rayos Láser , Ensayo de Materiales , Propiedades de Superficie , Titanio/químicaRESUMEN
OBJECTIVE: For effective minimally invasive lumbar decompression, we changed the routine of segmental decompression. Using a high-speed drill or an ultrasound knife, we created a working channel, starting at the base of the spinous process of the upper vertebra slightly above the disc level, to target and decompress the contralateral recess, and termed it the translaminar crossover decompression (TCD). We evaluated the feasibility and compared the outcomes of a navigation-guided endoscopic translaminar crossover approach for segmental decompression (eTCD) in elderly patients with microscopic decompression using the same approach (mTCD). METHODS: A total of 740 elderly patients were enrolled in a prospective cohort study. Of the 740 patients, 297, who had undergone mTCD, and 253, who had undergone eTCD, completed a 1-year follow-up visit. In addition to the surgical data, numerical rating scales (NRSs) for back and leg pain, the Core Outcome Measures Index and Oswestry Disability Index were recorded preoperatively and 3, 6, and 12 months after surgery. The MacNab criteria were supplemented by qualitative assessment of the patients' postoperative pain-free walking distance. RESULTS: A comparison of the preoperative and postoperative clinical scores showed significant improvement after TCD in both cohorts (P < 0.01): Oswestry Disability Index, from 50.3% ± 12.6% to 15.5% ± 7.43%; NRS (back), from 6.9 ± 1.9 to 2.5 ± 1.3; NRS (leg), from 8.0 ± 0.85 to 1.6 ± 0.33; Core Outcome Measures Index (back), from 7.8 ± 2.0 to 2.7 ± 1.5. No statistically significant differences were found in the outcomes between the 2 cohorts. CONCLUSIONS: TCD inherently eliminated central stenosis and facilitated decompression of both recesses via mutual undercutting, with preservation of facet joint integrity.
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Descompresión Quirúrgica/métodos , Neuroendoscopía/métodos , Estenosis Espinal/cirugía , Anciano , Dolor de Espalda/etiología , Dolor de Espalda/cirugía , Descompresión Quirúrgica/instrumentación , Evaluación de la Discapacidad , Diseño de Equipo , Femenino , Humanos , Claudicación Intermitente/etiología , Claudicación Intermitente/cirugía , Vértebras Lumbares/cirugía , Imagen por Resonancia Magnética , Masculino , Microcirugia/instrumentación , Microcirugia/métodos , Neuroendoscopía/instrumentación , Neuronavegación/instrumentación , Neuronavegación/métodos , Estudios Prospectivos , Tomografía Computarizada por Rayos XRESUMEN
The aim of this work was to investigate the microstructure and mechanical properties of samples produced by direct metal laser sintering (DMLS) with varied laser beam speed before and after heat treatment. Optical analysis of as-built samples revealed microstructure built of martensite needles and columnar grains, growing epitaxially towards the built direction. External and internal pores, un-melted or semi-melted powder particles and inclusions in the examined samples were also observed. The strength and Young's modulus of the DMLS samples before heat treatment was higher than for cast and forged samples; however, the elongation at break for vertical and horizontal orientation was lower than required for biomedical implants. After heat treatment, the hardness of the samples decreased, which is associated with the disappearance of boundary effect and martensite decomposition to lamellar mixture of α and ß, and the anisotropic behaviour of the material also disappears. Ultimate tensile strength (UTS) and yield strength(YS) also decreased, while elongation increased. Tensile properties were sensitive to the build orientation, which indicates that DMLS generates anisotropy of material as a result of layered production and elongated ß prior grains. It was noticed that inappropriate selection of parameters did not allow properties corresponding to the standards to be obtained due to the high porosity and defects of the microstructure caused by insufficient energy density.
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PURPOSE: The objective of this study was to fabricate PLA-based porous scaffold by 3D printing technology and to evaluate their cytotoxicity and biocompatibility under in vitro conditions in respect to bone tissue engineering. MATERIAL AND METHODS: Pure PLA in filamentous form was processed via 3D printing technology of fused filament fabrication into porous scaffolds. The structure and porosity of scaffolds were measured by metrotomography. PLA scaffolds were pre-treated by human serum, foetal bovine serum and complete cell culture medium to enhance bio-attractivity of the scaffold's surface for the adherence of the cells. Cells were enzymatically isolated from the periosteum of the proximal tibia and then expanded in monolayer. Periosteum-derived osteoprogenitors (PDOs) were seeded on the pre-treated PLA scaffolds and subsequent cell proliferation was measured by commercially available cell proliferation assay. Adherence of PDOs on the PLA scaffold was confirmed by scanning electron microscopy (SEM). RESULTS: Prepared scaffolds had well-defined structure and were characterized by uniform distribution of pores. They were non-toxic and biocompatible with PDOs, however, PLA scaffold with the periosteum-derived progenitor cells was significantly better in the group of scaffolds pre-treated with normal human serum. CONCLUSIONS: The obtained PLA porous scaffolds favored attachment of periosteum derived progenitors and proliferation, furthermore, cells penetrated into the scaffold through the interstitial pores which was meaningful for cytocompatibility evaluation.
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Huesos/fisiología , Poliésteres/farmacología , Impresión Tridimensional , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Equilibrio Ácido-Base/efectos de los fármacos , Huesos/diagnóstico por imagen , Huesos/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Femenino , Humanos , Persona de Mediana Edad , Periostio/citología , Porosidad , Células Madre/citología , Células Madre/ultraestructura , Tomografía Computarizada por Rayos XRESUMEN
Additive manufacturing has a great potential for creating hard tissue substitutes, such as bone and cartilage, or soft tissues, such as vascular and skin grafts. This study is a pilot study for 3D printing of a new material mixture potentially used as a tubular substitute for urethra replacement. This new mixture is a blend of polylactic acid (PLA) and polyhydroxybutyrate (PHB). The basic aspect that affects the 3D printing process is correct material preparation and setting of 3D printer parameters. Selection of material and printing parameters depend on printing technology. The printing technology affects material behavior during printing process. The goal of preprocessing and 3D printing process is to provide stabile conditions during manufacturing to obtain usable printed samples. The study deals with preparation of material before 3D printing - material drying. Moisture in material affects material degradation and viscosity during printing. According to this, it is necessary to verify recommended drying parameters. Verification was performed by printing strand samples from dried and non-dried material and also by calculating and comparing respective viscosities that change in time. Printed strand clearly show that non-dried material degrades in less than 10 min, what leads to inappropriate application in short-time printing. Dried material shows significant stability and degrades slightly during selected time span. For metrological verification of material stability two sample types were designed and manufactured - a cubic sample which represents basic scaffold structures and a tubular one that serves as urethra substitution. Obtained results showed appropriate usability of selected technology and printing parameters for PLA / PHB material blend.