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1.
Enzyme Microb Technol ; 150: 109867, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34489026

RESUMO

The main problem for submerged fermentation of filamentous fungi is the nutrition limitation with high cell density or cell leakage by the uncontrollable hyphae, clusters, or pellets. There are several techniques such as microparticle, immobilization, pH shifting, substrate limitation etc. for controlling filamentous fungi growth on submerged fermentation. In this research, FDM (Fused Deposition Modelling) based 3D printed cubes is used for growth control agent of recombinant Aspergillus sojae for the first time. Lattice structure sizes, number of cubes and pH were chosen to be main factors of fermentation in order to study the combine effect of the factors on A. sojae fermentation. The results revealed that specific activity values are improved from 2045.96 U/mg (the highest control activity) to 3291.67 U/mg with lower pellet sizes and controllable growth. FDM based 3D printed cubes was successfully controlled the recombinant Aspergillus sojae fermentation and enhanced ß-mannanase production. In addition, this research was also showed that FDM based 3D printed cubes also have the potential to be used as immobilization materials like SLS based 3D printed products in further research.


Assuntos
Fungos , Impressão Tridimensional , Aspergillus , Contagem de Células , Fermentação
2.
Georgian Med News ; (316-317): 173-178, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34511467

RESUMO

The advantage of polylactide-based implants is their rapid and complete biodegradation, followed by replacement of the defect with bone tissue. The disadvantage of materials with a high biodegradation rate is their low support ability. The admixture of ceramic materials increases the strength of the implants and reduces the rate of biodegradation. 3D printing technology allows you to reduce the negative factors of ceramic impurities through the manufacture of implants of various porosities. Target. Determine the ultimate strength of a composite material based on PLA and TCP, manufactured by 3D printing with different porosity options, depending on the duration of hydration. Were made 9 samples of material with a size of 10x10x10 mm with different porosity 40%, 30%, 20%. Samples of the material were hydrated in saline. Strength tests were carried out on days 2, 10, and 20 after hydration, 3 samples of material of each porosity. All samples were tested for compression. The carried out comparative analysis indicates that the tested samples are statistically significant (at the level of p <0.05) differ from each other depending on the value of porosity at all periods of hydration. Although the average values of the ultimate strength of samples of the same porosity tend to decrease depending on the period of their hydration, these changes do not acquire statistical significance even between the extreme periods of observation. This is confirmed by the values of the indicator of the statistical significance of the differences p equal to 0.07; 0.759 and 0.124 for specimens with porosity of 20%, 30% and 40%, respectively. The tensile strength of samples of material based on polylactide and tricalcium phosphate, made using 3D printing, directly depends on their porosity, the smaller the pore volume, the stronger the samples. The hydration of the samples in saline solution for 20 days does not entail statistically significant changes in their strength regardless of the pore volume, although the average values of the ultimate strength for all tested samples tend to decrease.


Assuntos
Poliésteres , Tecidos Suporte , Fosfatos de Cálcio , Teste de Materiais , Porosidade , Impressão Tridimensional
3.
Sensors (Basel) ; 21(17)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34502787

RESUMO

The possibility to shape stimulus-responsive optical polymers, especially hydrogels, by means of laser 3D printing and ablation is fostering a new concept of "smart" micro-devices that can be used for imaging, thermal stimulation, energy transducing and sensing. The composition of these polymeric blends is an essential parameter to tune their properties as actuators and/or sensing platforms and to determine the elasto-mechanical characteristics of the printed hydrogel. In light of the increasing demand for micro-devices for nanomedicine and personalized medicine, interest is growing in the combination of composite and hybrid photo-responsive materials and digital micro-/nano-manufacturing. Existing works have exploited multiphoton laser photo-polymerization to obtain fine 3D microstructures in hydrogels in an additive manufacturing approach or exploited laser ablation of preformed hydrogels to carve 3D cavities. Less often, the two approaches have been combined and active nanomaterials have been embedded in the microstructures. The aim of this review is to give a short overview of the most recent and prominent results in the field of multiphoton laser direct writing of biocompatible hydrogels that embed active nanomaterials not interfering with the writing process and endowing the biocompatible microstructures with physically or chemically activable features such as photothermal activity, chemical swelling and chemical sensing.


Assuntos
Materiais Biocompatíveis , Hidrogéis , Lasers , Polímeros , Impressão Tridimensional
4.
Mater Sci Eng C Mater Biol Appl ; 128: 112310, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474861

RESUMO

Intervertebral disc (IVD) degeneration is a clinically disease that seriously endangers people's health. Tissue engineering provides a promising method to repair and regenerate the damaged IVD physiological function. Successfully tissue-engineered IVD scaffold should mimic the native IVD histological and macro structures. Here, 3D printing and electrospinning were combined to construct an artificial IVD composite scaffold. Poly lactide (PLA) was used to print the IVD frame structure, the oriented porous poly(l-lactide)/octa-armed polyhedral oligomeric silsesquioxanes (PLLA/POSS-(PLLA)8) fiber bundles simulated the annulus fibrosus (AF), and the gellan gum/poly (ethylene glycol) diacrylate (GG/PEGDA) double network hydrogel loaded with bone marrow mesenchymal stem cells (BMSCs) simulated the nucleus pulposus (NP) structure. Morphological and mechanical tests showed that the structure and mechanical properties of the IVD scaffold were similar to that of the natural IVD. The compression modulus of the scaffold is about 10 MPa, which is comparable to natural IVD and provides good mechanical support for tissue repair and regeneration. At the same time, the porosity and mechanical properties of the scaffold can be regulated through the 3D model design. In the AF structure, the fiber bundles are oriented concentrically with each subsequent layer oriented 60° to the spinal column, and can withstand the tension generated during the deformation of the NP. In the NP structure, BMSCs were evenly distributed in the hydrogel and could maintain high cell viability. Animal experiment results demonstrated that the biomimetic artificial IVD scaffold could maintain the disc space and produce the new extracellular matrix. This engineered biomimetic IVD scaffold is a promising biomaterial for individualized IVD repair and regeneration.


Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , Animais , Biomimética , Humanos , Degeneração do Disco Intervertebral/terapia , Impressão Tridimensional , Engenharia Tecidual , Tecidos Suporte
5.
Mater Sci Eng C Mater Biol Appl ; 128: 112326, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474877

RESUMO

Bone defects remain a challenging problem for doctors and patients in clinical practice. Processed pyritum is a traditional Chinese medicine that is often used to clinically treat bone fractures. It contains mainly Fe, Zn, Cu, Mn, and other elements. In this study, we added the extract of processed pyritum to ß-tricalcium phosphate and produced a porous composite TPP (TCP/processed pyritum) scaffold using digital light processing (DLP) 3D printing technology. Scanning electron microscopy (SEM) analysis revealed that TPP scaffolds contained interconnected pore structures. When compared with TCP scaffolds (1.35 ± 0.15 MPa), TPP scaffolds (5.50 ± 0.24 MPa) have stronger mechanical strength and can effectively induce osteoblast proliferation, differentiation, and mineralization in vitro. Meanwhile, the in vivo study showed that the TPP scaffold had better osteogenic capacity than the TCP scaffold. Furthermore, the TPP scaffold had good biosafety after implantation. In summary, the TPP scaffold is a promising biomaterial for the clinical treatment of bone defects.


Assuntos
Fosfatos de Cálcio , Tecidos Suporte , Humanos , Porosidade , Impressão Tridimensional
6.
Mater Sci Eng C Mater Biol Appl ; 128: 112333, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474884

RESUMO

Polyetheretherketone (PEEK) was widely applied into fabricating of orthopaedic implants, benefitting its excellent biocompatibility and similar mechanical properties to native bones. However, the inertness of PEEK hinders its integration with the surrounding bone tissue. Here PEEK scaffolds with a series of hydroxyapatite (HA) contents in gradient were manufactured via fused filament fabrication (FFF) 3D printing techniques. The influence of the pore size, HA content and printing direction on the mechanical properties of the PEEK/HA scaffolds was systematically evaluated. By adjusting the pore size and HA contents, the elastic modulus of the PEEK/HA scaffolds can be widely tuned in the range of 624.7-50.6 MPa, similar to the variation range of natural cancellous bone. Meanwhile, the scaffolds exhibited higher Young's modulus and lower compressive strength along Z printing direction. The mapping relationship among geometric parameters, HA content, printing direction and mechanical properties was established, which gave more accurate predictions and controllability of the modulus and strength of scaffolds. The PEEK/HA scaffolds with the micro-structured surface could promote cell attachment and mineralization in vitro. Therefore, the FFF-printed PEEK/HA composites scaffolds can be a good candidate for bone grafting and tissue engineering.


Assuntos
Durapatita , Cetonas , Benzofenonas , Polietilenoglicóis , Polímeros , Porosidade , Impressão Tridimensional , Tecidos Suporte
7.
Mater Sci Eng C Mater Biol Appl ; 128: 112336, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474887

RESUMO

This study used methylcellulose (MC) to improve the printability of the alginate dialdehyde-gelatin (ADA-GEL) based bioink. The printability as well as the capability to maintain shape fidelity of ADA-GEL could be enhanced by the addition of 9% (w/v) MC. Moreover, the properties of the ink crosslinked with Ca2+ and Ba2+ were investigated. The samples crosslinked with Ba2+ were more stable and stiffer than the Ca2+ crosslinked samples. However, both Ca2+ and Ba2+ crosslinked samples exhibited a similar trend of MC release during incubation under cell culture conditions. The toxicity test indicated that both samples (crosslinked with Ca2+ and Ba2+) exhibited no toxic potential. The fabrication of cell-laden constructs using the developed bioinks was evaluated. The viability of ST2 cells in Ba2+ crosslinked samples increased while for Ca2+ crosslinked samples, a decreased viability was observed over the incubation time. After 21 days, cell spreading in the hydrogels crosslinked with Ba2+ occurred. However, a certain degree of cell damage was observed after incorporating the cells in the high viscosity bioink.


Assuntos
Bioimpressão , Gelatina , Alginatos , Sobrevivência Celular , Hidrogéis , Metilcelulose , Impressão Tridimensional , Tecidos Suporte
8.
Mater Sci Eng C Mater Biol Appl ; 128: 112357, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474904

RESUMO

Bioprinting technology offers layer-by-layer positioning of cells within 3D space with complexity and a defined architecture. Cancer models based in this biofabrication technique are important tools to achieve representative and realistic in vivo conditions of the tumor microenvironment. Here, we show the development of a proof-of-concept three-dimensional bioprinted cancer model that successfully recapitulates the intercellular communication via the assembly of functional tunneling nanotube (TNT)-like cell projections. Different combinations of collagen-containing culture medium, sodium alginate and gelatin were initially prepared and rheologically evaluated. The optimized mixture was used to print two preliminary 3D models for cancer cell seeding. Favourable results in cell viability and proliferation led to the inclusion of 786-O renal cancer cells into the biomaterial mixture to directly bioprint the most suitable 3D model with embedded cells. Bioprinted cells remained viable for at least 15 days of culture and proliferated. More importantly, these cancer cells were able to build TNT-like cellular projections inside the hydrogel that established direct contacts between distant cells. We show that these structures were used as channels for the scrolling and intercellular transfer of mitochondria thus reproducing TNT's function in 2D culture systems. This 3D bioprinted renal cancer model provides a novel alternative tool for studying the functional relevance of TNT-like structures in tumorigenesis and anticancer drug susceptibility in a highly controlled and reproducible tumor microenvironment.


Assuntos
Bioimpressão , Nanotubos , Neoplasias , Gelatina , Hidrogéis , Impressão Tridimensional
9.
Shanghai Kou Qiang Yi Xue ; 30(3): 283-287, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34476446

RESUMO

PURPOSE: To explore the application value of 3D printing technology under three-dimensional reconstruction in mandibular reconstruction. METHODS: Eighty-four patients with mandibular defect reconstruction were divided into two groups by different operation methods: 3D group(n=42) and control group(n=42). Patients in the control group underwent routine operation, while patients in the experimental(3D) group underwent three-dimensional reconstruction with 3D printing technology. The operation conditions, incidence of complications, recovery of facial features and occlusal relationship were recorded. SPSS 23.0 software package was used for statistical analysis of the data. RESULTS: The operation time of 3D group was significantly shorter than that of the control group, and the amount of bleeding was significantly less than that of the control group(P<0.05). The recovery rate of facial appearance and occlusal relationship in 3D group was significantly higher than in the control group(95.24% vs 78.57%, P<0.05). Compared with the control group, the movement distance of mandibular points in 3D group was significantly smaller before and after operation(P<0.05). The satisfaction scores of chewing function and pronunciation recovery in the two groups were close(P>0.05), but compared with the control group, the satisfaction scores of appearance recovery in the 3D group were significantly higher(P<0.05). CONCLUSIONS: 3D reconstruction under 3D printing technology can reduce intraoperative bleeding, shorten the operation duration, and achieve good shape recovery with high degree of satisfaction.


Assuntos
Imageamento Tridimensional , Reconstrução Mandibular , Humanos , Mandíbula/cirurgia , Impressão Tridimensional
10.
Adv Exp Med Biol ; 1334: 23-37, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34476743

RESUMO

Improved spatial awareness is vital in anatomy education as well as in many areas of medical practice. Many healthcare professionals struggle with the extrapolation of 2D data to its locus within the 3D volume of the anatomy. In this chapter, we outline the use of touch as an important sensory modality in the observation of 3D forms, including anatomical parts, with the specific neuroscientific underpinnings in this regard being described. We explore how improved spatial awareness is directly linked to improved spatial skill. The reader is offered two practical exercises that lead to improved spatial awareness for application in exploring external 3D anatomy volume as well as internal 3D anatomy volume. These exercises are derived from the Haptico-visual observation and drawing (HVOD) method. The resulting cognitive improvement in spatial awareness that these exercises engender can be of benefit to students in their study of anatomy and for application by healthcare professionals in many aspects of their medical practice. The use of autostereoscopic visualisation technology (AS3D) to view the anatomy from DICOM data, in combination with the haptic exploration of a 3D print (3Dp) of the same stereoscopic on-screen image, is recommended as a practice for improved understanding of any anatomical part or feature. We describe a surgical innovation that relies on the haptic perception of patients' 3D printed (3Dp) anatomical features from patient DICOM data, for improved surgical planning and in-theatre surgical performance. Throughout the chapter, underlying neuroscientific correlates to haptic and visual observation, memory, working memory, and cognitive load are provided.


Assuntos
Estudantes de Medicina , Cognição , Humanos , Imageamento Tridimensional , Modelos Anatômicos , Impressão Tridimensional , Tecnologia
11.
BMC Med Educ ; 21(1): 480, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34496844

RESUMO

BACKGROUND: Three-dimensional (3D) printing technology enables the translation of 2-dimensional (2D) medical imaging into a physical replica of a patient's individual anatomy and may enhance the understanding of congenital heart defects (CHD). We aimed to evaluate the usefulness of a spectrum of 3D-printed models in teaching CHD to medical students. RESULTS: We performed a prospective, randomized educational procedure to teach fifth year medical students four CHDs (atrial septal defect (ASD, n = 74), ventricular septal defect (VSD, n = 50), coarctation of aorta (CoA, n = 118) and tetralogy of Fallot (ToF, n = 105)). Students were randomized into printing groups or control groups. All students received the same 20 min lecture with projected digital 2D images. The printing groups also manipulated 3D printed models during the lecture. Both groups answered an objective survey (Multiple-choice questionnaire) twice, pre- and post-test, and completed a post-lecture subjective survey. Three hundred forty-seven students were included and both teaching groups for each CHD were comparable in age, sex and pre-test score. Overall, objective knowledge improved after the lecture and was higher in the printing group compared to the control group (16.3 ± 2.6 vs 14.8 ± 2.8 out of 20, p < 0.0001). Similar results were observed for each CHD (p = 0.0001 ASD group; p = 0.002 VSD group; p = 0.0005 CoA group; p = 0.003 ToF group). Students' opinion of their understanding of CHDs was higher in the printing group compared to the control group (respectively 4.2 ± 0.5 vs 3.8 ± 0.4 out of 5, p < 0.0001). CONCLUSION: The use of 3D printed models in CHD lectures improve both objective knowledge and learner satisfaction for medical students. The practice should be mainstreamed.


Assuntos
Cardiopatias Congênitas , Estudantes de Medicina , Cardiopatias Congênitas/diagnóstico por imagem , Humanos , Modelos Anatômicos , Impressão Tridimensional , Estudos Prospectivos
12.
Anal Chem ; 93(33): 11388-11397, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34375077

RESUMO

The construction of a dispersive optical spectrometer using three-dimensional (3D) design software and printing, without applying any optical adjustments, its validation, and application to quantification of ethanol in multiproduct liquids, is the objective of this work. A 3D design software was used to design a near-infrared (NIR) spectrometer in the region from 800 to 1600 nm from the dimensions of commercially available optical components. The project was printed on a polymer filament 3D printer, and the components were fitted to the printed part. Software calculations using the model design parameters were applied to attribute the wavelength values to the abscissa axis in the spectra and estimate errors due to 3D printing limitations. The alignment of the spectrum was proven using the chloroform absorbance spectrum, which presented a maximum mispositioning of 4.1 nm concerning the literature data and effective bandwidths equivalent to commercial instruments. The 3D-printed instrument was applied to quantify ethanol in samples of cachaça, rum, beer, brandy, whiskey, vodka, mouth wash, alcohol gel, and commercial alcohol solutions. Partial least-squares regression models were built for the 3D-printed instrument and two commercial NIR instruments, the MPA II (Bruker) and the NIR DLP NIRscan (Texas Instruments), using a group of 180 standards. The three instruments reached excellent predictive capability with similar root mean square error of cross-validation (2.36-2.68) and prediction (2.31-2.87). The correlation coefficient of cross-validation and prediction for all models were between 0.97 and 0.98. The results show the feasibility of building a 3D-printed dispersive spectrometer ready for application with the simple docking of the optics, presenting acceptable accuracy to the project design concerning the printing limitations.


Assuntos
Etanol , Polímeros , Calibragem , Impressão Tridimensional , Software
13.
Nat Commun ; 12(1): 5059, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34429413

RESUMO

With the current interest in cultured meat, mammalian cell-based meat has mostly been unstructured. There is thus still a high demand for artificial steak-like meat. We demonstrate in vitro construction of engineered steak-like tissue assembled of three types of bovine cell fibers (muscle, fat, and vessel). Because actual meat is an aligned assembly of the fibers connected to the tendon for the actions of contraction and relaxation, tendon-gel integrated bioprinting was developed to construct tendon-like gels. In this study, a total of 72 fibers comprising 42 muscles, 28 adipose tissues, and 2 blood capillaries were constructed by tendon-gel integrated bioprinting and manually assembled to fabricate steak-like meat with a diameter of 5 mm and a length of 10 mm inspired by a meat cut. The developed tendon-gel integrated bioprinting here could be a promising technology for the fabrication of the desired types of steak-like cultured meats.


Assuntos
Bioimpressão/métodos , Géis , Carne , Tendões , Animais , Bovinos , Técnicas de Cultura de Células , Colágeno , Células Endoteliais , Músculos/citologia , Músculos/fisiologia , Impressão Tridimensional , Células-Tronco , Tendões/citologia , Engenharia Tecidual
14.
Int J Mol Sci ; 22(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34360832

RESUMO

Microfluidic technique has emerged as a promising tool for the production of stable and monodispersed nanoparticles (NPs). In particular, this work focuses on liposome production by microfluidics and on factors involved in determining liposome characteristics. Traditional fabrication techniques for microfluidic devices suffer from several disadvantages, such as multistep processing and expensive facilities. Three-dimensional printing (3DP) has been revolutionary for microfluidic device production, boasting facile and low-cost fabrication. In this study, microfluidic devices with innovative micromixing patterns were developed using fused deposition modelling (FDM) and liquid crystal display (LCD) printers. To date, this work is the first to study liposome production using LCD-printed microfluidic devices. The current study deals with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes with cholesterol (2:1) prepared using commercial and 3D-printed microfluidic devices. We evaluated the effect of microfluidic parameters, chip manufacturing, material, and channel design on liposomal formulation by analysing the size, PDI, and ζ-potential. Curcumin exhibits potent anticancer activity and it has been reported that curcumin-loaded liposomes formulated by microfluidics show enhanced encapsulation efficiency when compared with other reported systems. In this work, curcumal liposomes were produced using the developed microfluidic devices and particle sizing, ζ-potential, encapsulation efficiency, and in vitro release studies were performed at 37 °C.


Assuntos
Curcumina/administração & dosagem , Sistemas de Liberação de Medicamentos , Lipossomos , Microfluídica/instrumentação , Nanopartículas , Impressão Tridimensional
15.
Int J Mol Sci ; 22(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34445228

RESUMO

Recent advancements in medical imaging, virtual surgical planning (VSP), and three-dimensional (3D) printing have potentially changed how today's craniomaxillofacial surgeons use patient information for customized treatments. Over the years, polyetheretherketone (PEEK) has emerged as the biomaterial of choice to reconstruct craniofacial defects. With advancements in additive manufacturing (AM) systems, prospects for the point-of-care (POC) 3D printing of PEEK patient-specific implants (PSIs) have emerged. Consequently, investigating the clinical reliability of POC-manufactured PEEK implants has become a necessary endeavor. Therefore, this paper aims to provide a quantitative assessment of POC-manufactured, 3D-printed PEEK PSIs for cranial reconstruction through characterization of the geometrical, morphological, and biomechanical aspects of the in-hospital 3D-printed PEEK cranial implants. The study results revealed that the printed customized cranial implants had high dimensional accuracy and repeatability, displaying clinically acceptable morphologic similarity concerning fit and contours continuity. From a biomechanical standpoint, it was noticed that the tested implants had variable peak load values with discrete fracture patterns and failed at a mean (SD) peak load of 798.38 ± 211.45 N. In conclusion, the results of this preclinical study are in line with cranial implant expectations; however, specific attributes have scope for further improvements.


Assuntos
Benzofenonas , Sistemas Automatizados de Assistência Junto ao Leito , Polímeros , Impressão Tridimensional , Próteses e Implantes , Crânio/lesões , Humanos , Procedimentos Cirúrgicos Reconstrutivos
16.
J Theor Biol ; 528: 110852, 2021 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-34358535

RESUMO

Tissue growth in three-dimensional (3D) printed scaffolds enables exploration and control of cell behaviour in more biologically realistic geometries than that allowed by traditional 2D cell culture. Cell proliferation and migration in these experiments have yet to be explicitly characterised, limiting the ability of experimentalists to determine the effects of various experimental conditions, such as scaffold geometry, on cell behaviour. We consider tissue growth by osteoblastic cells in melt electro-written scaffolds that comprise thin square pores with sizes that were deliberately increased between experiments. We collect highly detailed temporal measurements of the average cell density, tissue coverage, and tissue geometry. To quantify tissue growth in terms of the underlying cell proliferation and migration processes, we introduce and calibrate a mechanistic mathematical model based on the Porous-Fisher reaction-diffusion equation. Parameter estimates and uncertainty quantification through profile likelihood analysis reveal consistency in the rate of cell proliferation and steady-state cell density between pore sizes. This analysis also serves as an important model verification tool: while the use of reaction-diffusion models in biology is widespread, the appropriateness of these models to describe tissue growth in 3D scaffolds has yet to be explored. We find that the Porous-Fisher model is able to capture features relating to the cell density and tissue coverage, but is not able to capture geometric features relating to the circularity of the tissue interface. Our analysis identifies two distinct stages of tissue growth, suggests several areas for model refinement, and provides guidance for future experimental work that explores tissue growth in 3D printed scaffolds.


Assuntos
Impressão Tridimensional , Tecidos Suporte , Proliferação de Células , Análise de Dados , Porosidade , Engenharia Tecidual
17.
Water Sci Technol ; 84(3): 752-762, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34388132

RESUMO

In this study, an electro-oxidation (EO) process using graphite electrodes as electrode pairs was used for the removal of chemical oxygen demand (COD), ammoniacal nitrogen (NH4+-N), and color from real textile printing wastewater. The effects of solution pH, sodium chloride (NaCl) dosage, sodium hypochlorite (NaOCl), which is the oldest and still most important chlorine-based bleach, dosage, and oxidation time were investigated on the removal efficiencies. Operating conditions for the EO reactor were applied to current density 1 mA/cm2, distance between the electrodes: 2 cm, 150 min operation time, and stirring speed of 500 rpm. At optimum conditions: pH 9.5, applied current density 1 mA/cm2, NaCl dosage of 8 g/L, NaOCl dosage of 44.4 mg/L and 150 min electro-oxidation time, the obtained removal efficiencies were 86.5% and 91.1% for chemical oxygen demand (COD) and ammoniacal nitrogen, respectively. Efficiency was increased to 91.1% for ammoniacal nitrogen from 21.7% after applying EO combined with NaOCl addition compared to individual NaOCl addition.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Análise da Demanda Biológica de Oxigênio , Eletrodos , Nitrogênio , Oxirredução , Impressão Tridimensional , Cloreto de Sódio , Têxteis , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/análise
18.
BMJ Case Rep ; 14(8)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344652

RESUMO

Patients with rapidly progressing periodontitis may require extractions of teeth with poor periodontal prognosis. Although replacement with a dental implant is a popular choice, teeth autotransplantation remains a viable option. Herein, we report a case of a 23-year-old patient with rapidly progressing periodontitis resulting in severe clinical attachment loss on the left maxillary first molar, which required extraction. The tooth was replaced by tooth autotransplantation of the unerupted immature left mandibular third molar, which was delivered carefully without compromising the periodontal ligament. Cone beam computed tomography and three-dimensional printing of the third molar donor tooth significantly aided the tooth autotransplantation procedure. Recovery was uneventful. At the 1-year follow-up, healthy periodontal parameters and radiographic features were noted, and the autotransplanted tooth remained vital. This case showed that tooth autotransplantation is a viable option for replacing tooth loss due to rapidly progressing periodontitis.


Assuntos
Periodontite , Dente , Adulto , Humanos , Dente Molar/diagnóstico por imagem , Dente Molar/cirurgia , Dente Serotino/diagnóstico por imagem , Dente Serotino/cirurgia , Periodontite/complicações , Periodontite/diagnóstico por imagem , Periodontite/cirurgia , Impressão Tridimensional , Transplante Autólogo , Adulto Jovem
19.
Zhongguo Gu Shang ; 34(8): 764-9, 2021 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-34423622

RESUMO

OBJECTIVE: The finite element analysis method was used to compare the biomechanical performance of the individualized interbody fusion cage, the clinically common double bullet type fusion cage and the healthy lumbar spine model under different working conditions. METHODS: According to the CT scan data of the lumbar spine of a real healthy human body, a finite element model of the lumbar spine of a healthy human body was designed using finite element software as a normal control group. On this basis, the individualized lumbar fusion cage model and the clinical standard bullet type fusion cage lumbar spine model were further established. These three finite element models were applied with different loads such as vertical compression, forward flexion, extension, and lateral bending to observethe changes in the stress distribution and stress magnitude of each component of the lumbar spine. RESULTS: The maximum stress values of the vertebral body and the fusion cage under the extension condition in the clinical standard bullet type fusion cage lumbar spine model were 45.81 MPa and 97.07 MPa, respectively. The stress of the vertebral body and the fusion cage in the individualized lumbar fusion cage model was closer to the stress of the vertebral body and the intervertebral disc in the healthy lumbar spine model. From the perspective of displacement, the displacement of each component of the lumbar spine models of the two fusion cages was smaller than that of the healthy lumbar spine model, indicated that the internal fixation of the fusion cage limited the range of motion of the vertebral body. On the other hand, it also confirmed the validity of the finite element model established in the study. The displacement of the fusion cage and the vertebral body in the individualized model under different working conditions was generally smaller thanthat of the standard model fusion cage and the vertebral body. CONCLUSION: The fusion cage can replace the diseased intervertebral disc to a certain extent, so as to reduce the patient's pain and restore the lumbar function. The personalized design of the fusion cage can better meet the needs of individual patients, which has the great significance to the recovery of the patient's lumbar spine function, the service life of the fusion cage and the protection of the contact vertebral body, and provides certain guidance for actual clinical treatment.


Assuntos
Fusão Vertebral , Desenho de Equipamento , Humanos , Vértebras Lombares/cirurgia , Impressão Tridimensional , Amplitude de Movimento Articular
20.
Anal Chem ; 93(32): 11208-11214, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34339178

RESUMO

Biocompatible hydrogels for tissue regeneration/replacement and drug release with specific architectures can be obtained by three-dimensional bioprinting techniques. The preservation of the higher order structure of the proteins embedded in the hydrogels as drugs or modulators is critical for their biological activity. Solution nuclear magnetic resonance (NMR) experiments are currently used to investigate the higher order structure of biotherapeutics in comparability, similarity, and stability studies. However, the size of pores in the gel, protein-matrix interactions, and the size of the embedded proteins often prevent the use of this methodology. The recent advancements of solid-state NMR allow for the comparison of the higher order structure of the matrix-embedded and free isotopically enriched proteins, allowing for the evaluation of the functionality of the material in several steps of hydrogel development. Moreover, the structural information at atomic detail on the matrix-protein interactions paves the way for a structure-based design of these biomaterials.


Assuntos
Bioimpressão , Liberação Controlada de Fármacos , Hidrogéis , Impressão Tridimensional , Engenharia Tecidual , Tecidos Suporte
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