scholarly journals Controlling the crystallinity and solubility of functional PCL with efficient post-polymerisation modification

2021 ◽  
Author(s):  
Cinzia Clamor ◽  
Beatrice Cattoz ◽  
Peter Wright ◽  
Rachel K. O'Reilly ◽  
Andrew P Dove

Poly(ε-caprolactone) is a semi-crystalline biocompatible polymer with good mechanical properties. Its crystallinity also uniquely enables poly(ε-caprolactone) to be used in different applications, from the development of 3D scaffolds for tissue...

2015 ◽  
Vol 7 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Nandana Bhardwaj ◽  
Wan Ting Sow ◽  
Dipali Devi ◽  
Kee Woei Ng ◽  
Biman B. Mandal ◽  
...  

Development of highly vascular dermal tissue-engineered skin substitutes with appropriate mechanical properties and cellular cues is in need for significant advancement in the field of dermal reconstruction.


2017 ◽  
Vol 8 (6) ◽  
pp. 587-591
Author(s):  
Deividas Mizeras ◽  
Andžela Šešok ◽  
Algirdas Vaclovas Valiulis ◽  
Justinas Gargasas ◽  
Irmantas Gedzevičius

One of the biggest challenges in modern tissue engineering is a creation 3D scaffolds for bone tissue regeneration. Until now, in order to restore bone defects are used various bone substitutes (autologous and allogeneic), however, their usage is limited because is required additional surgery, possible complications, also limited their use is associated with ethical point of view. In this work we aim to determine the mechanical properties of 3D printed PLA objects having various orientation woodpile microarchitectures. In this work we chose three different 3D microarchitectures: woodpile BCC (each layer consists of parallel logs which are rotated 90 deg every next layer), woodpile FCC (every layer is additionally shifted half of the period in respect to the previous parallel log layer) and a rotating woodpile 60 deg (each layer is rotated 60 deg in respect to the previous one). Compressive and bending tests were carried out with TIRAtest2300 universal testing machine. We found that 60 deg rotating woodpile geometry had the highest mechanical values which were approximately about 3 times higher than the BCC or FCC microstructures. Vienas didžiausių šiuolaikinės audinių inžinerijos iššūkių yra 3D karkasų, skirtų kaulinio audinio regeneracijai, sukūrimas. Iki šiol, norint atstatyti kaulo defektus, naudojami įvairūs kaulo pakaitalai (autogeniniai ir alogeniniai), kurių naudojimo galimybės jau nebeatitinka poreikių, nes reikalinga papildoma operacija, galimos komplikacijos, taip pat ribotas jų naudojimas, susijęs su etinėmis pažiūromis. Šiame darbe lyginamos 3D spausdintuvu suformuotų mikrodarinių, skirtų kaulinio audinio defektui atkurti, mechaninės savybės. Darbe pasirinktos trys skirtingos 3D karkasų mikrostruktūros: woodpile BCC (kiekvienas sluoksnis susideda iš lygiagrečių rąstų, kurie keičiami 90 laipsnių kampu prieš tai esančio sluoksnio atžvilgiu), woodpile FCC (kiekvienas sluoksnis papildomai keičiasi per pusę periodo sluoksnio, esančio prieš tai, atžvilgiu) ir woodpile 60 deg (besisukanti rąstų rietuvė, kiekvienas tokios gardelės sluoksnis yra pasuktas 60 laipsnių prieš tai esančios atžvilgiu). Gniuždymo ir lenkimo bandymai buvo atlikti TIRAtest 2300 universalia bandymų mašina. Buvo nustatyta, kad, taikant 60 laipsnių kampu besikeičiančią woodpile geometriją, galima pasiekti didžiausias mechanines vertes, kurios buvo maždaug tris kartus didesnės nei woodfile BCC arba woodfile FCCmikrostruktūros.


2018 ◽  
Vol 107 (4) ◽  
pp. 1079-1087 ◽  
Author(s):  
Aleksandra Kruk ◽  
Agnieszka Gadomska‐Gajadhur ◽  
Izabela Rykaczewska ◽  
Judyta Dulnik ◽  
Paweł Ruśkowski ◽  
...  

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1832 ◽  
Author(s):  
Chen-Guang Liu ◽  
Yu-Ting Zeng ◽  
Ranjith Kankala ◽  
Shan-Shan Zhang ◽  
Ai-Zheng Chen ◽  
...  

Some basic requirements of bone tissue engineering include cells derived from bone tissues, three-dimensional (3D) scaffold materials, and osteogenic factors. In this framework, the critical architecture of the scaffolds plays a crucial role to support and assist the adhesion of the cells, and the subsequent tissue repairs. However, numerous traditional methods suffer from certain drawbacks, such as multi-step preparation, poor reproducibility, high complexity, difficulty in controlling the porous architectures, the shape of the scaffolds, and the existence of solvent residue, which limits their applicability. In this work, we fabricated innovative poly(lactic-co-glycolic acid) (PLGA) porous scaffolds, using 3D-printing technology, to overcome the shortcomings of traditional approaches. In addition, the printing parameters were critically optimized for obtaining scaffolds with normal morphology, appropriate porous architectures, and sufficient mechanical properties, for the accommodation of the bone cells. Various evaluation studies, including the exploration of mechanical properties (compressive strength and yield stress) for different thicknesses, and change of structure (printing angle) and porosity, were performed. Particularly, the degradation rate of the 3D scaffolds, printed in the optimized conditions, in the presence of hydrolytic, as well as enzymatic conditions were investigated. Their assessments were evaluated using the thermal gravimetric analyzer (TGA), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). These porous scaffolds, with their biocompatibility, biodegradation ability, and mechanical properties, have enabled the embryonic osteoblast precursor cells (MC3T3-E1), to adhere and proliferate in the porous architectures, with increasing time. The generation of highly porous 3D scaffolds, based on 3D printing technology, and their critical evaluation, through various investigations, may undoubtedly provide a reference for further investigations and guide critical optimization of scaffold fabrication, for tissue regeneration.


RSC Advances ◽  
2020 ◽  
Vol 10 (14) ◽  
pp. 8548-8557
Author(s):  
Stephen J. Schmidt ◽  
Brian D. Holt ◽  
Anne M. Arnold ◽  
Stefanie A. Sydlik

Polyesters are a promising class of biocompatible polymer, however, their mechanical properties fall short of metals and ceramics. This paper covalently binds polyesters to graphenic moieties resulting in enhanced mechanical properties.


2009 ◽  
Vol 610-613 ◽  
pp. 1188-1191 ◽  
Author(s):  
Qing Shan Kong ◽  
Zi Sen Yu ◽  
Quan Ji ◽  
Yan Zhi Xia

In this study, biocompatible polymer poly(ethylene oxide) (PEO), gelation (denatured collagen) and nanometer silver colloid was added to the electrospinnning solution of alginate sodium to get anti-bacterial nanofiber mats. The morphology and mechanical properties of the electrospun mats have been investigated. Smooth fibers with diameters around 300 nm were obtained from 4.0 % solutions of varied alginate/PEO/gelation proportion. The anti-water property of the electrospun mats has been improved by crosslink with glutaraldehyde acetone solution and aqueous calcium chloride and ethanol.


Biomecánica ◽  
2019 ◽  
Vol 27 (1) ◽  
Author(s):  
Ana Mora Boza ◽  
Malgorzata K. Wlodarczyk-Biegun ◽  
Aránzazu Del Campo ◽  
Blanca Vázquez-Lasal ◽  
Julio San Román

Author(s):  
S. Fujishiro

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.


Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).


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