scholarly journals Crosslinking Kinetics of Methylcellulose Aqueous Solution and Its Potential as a Scaffold for Tissue Engineering

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1772 ◽  
Author(s):  
Beata Niemczyk-Soczynska ◽  
Arkadiusz Gradys ◽  
Dorota Kolbuk ◽  
Anna Krzton-Maziopa ◽  
Pawel Sajkiewicz
Keyword(s):  
Aqueous Solution ◽  
Tissue Engineering ◽  
Hydrophobic Interactions ◽  
Research Work ◽  
Mechanical Analysis ◽  
Biological Properties ◽  
Ambient Conditions ◽  
Scanning Calorimetry ◽  
Engineering Applications ◽  
Methoxy Groups

Thermosensitive, physically crosslinked injectable hydrogels are in the area of interests of various scientific fields. One of the representatives of this materials group is an aqueous solution of methylcellulose. At ambient conditions, methylcellulose (MC) is a sol while on heating up to 37 °C, MC undergoes physical crosslinking and transforms into a gel. Injectability at room temperature, and crosslinkability during subsequent heating to physiological temperature raises hopes, especially for tissue engineering applications. This research work aimed at studying crosslinking kinetics, thermal, viscoelastic, and biological properties of MC aqueous solution in a broad range of MC concentrations. It was evidenced by Differential Scanning Calorimetry (DSC) that crosslinking of MC is a reversible two-stage process, manifested by the appearance of two endothermic effects, related to the destruction of water cages around methoxy groups, followed by crosslinking via the formation of hydrophobic interactions between methoxy groups in the polymeric chains. The DSC results also allowed the determination of MC crosslinking kinetics. Complementary measurements of MC crosslinking kinetics performed by dynamic mechanical analysis (DMA) provided information on the final storage modulus, which was important from the perspective of tissue engineering applications. Cytotoxicity tests were performed using mouse fibroblasts and showed that MC at low concentration did not cause cytotoxicity. All these efforts allowed to assess MC hydrogel relevance for tissue engineering applications.

PLGA+HA/βTCP scaffold incorporating simvastatin: a promising biomaterial for bone tissue engineering

2020 ◽  
Author(s):  
Mariane Beatriz Sordi ◽  
Ariadne Cristiane Cabral da Cruz ◽  
Águedo Aragones ◽  
Mabel Mariela Rodríguez Cordeiro ◽  
Ricardo de Souza Magini
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Thermal Analyses ◽  
Chemical Properties ◽  
Biological Properties ◽  
Scanning Calorimetry ◽  
Evaporation Technique ◽  
Porosity Analysis ◽  
Biphasic Ceramic

The aim of this study was to synthesize, characterize, and evaluate degradation and biocompatibility of poly(lactic-co-glycolic acid) + hydroxyapatite / β-tricalcium phosphate (PLGA+HA/βTCP) scaffolds incorporating simvastatin (SIM) to verify if this biomaterial might be promising for bone tissue engineering. Samples were obtained by the solvent evaporation technique. Biphasic ceramic particles (70% HA, 30% βTCP) were added to PLGA in a ratio of 1:1. Samples with SIM received 1% (m:m) of this medication. Scaffolds were synthesized in a cylindric-shape and sterilized by ethylene oxide. For degradation analysis, samples were immersed in PBS at 37 °C under constant stirring for 7, 14, 21, and 28 days. Non-degraded samples were taken as reference. Mass variation, scanning electron microscopy, porosity analysis, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetry were performed to evaluate physico-chemical properties. Wettability and cytotoxicity tests were conducted to evaluate the biocompatibility. Microscopic images revealed the presence of macro, meso, and micropores in the polymer structure with HA/βTCP particles homogeneously dispersed. Chemical and thermal analyses presented very similar results for both PLGA+HA/βTCP and PLGA+HA/βTCP+SIM. The incorporation of simvastatin improved the hydrophilicity of scaffolds. Additionally, PLGA+HA/βTCP and PLGA+HA/βTCP+SIM scaffolds were biocompatible for osteoblasts and mesenchymal stem cells. In summary, PLGA+HA/βTCP scaffolds incorporating simvastatin presented adequate structural, chemical, thermal, and biological properties for bone tissue engineering.

scholarly journals Influences of Molecular Weights on Physicochemical and Biological Properties of Collagen-Alginate Scaffolds

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 85 ◽  
Author(s):  
Truc Cong Ho ◽  
Jin-Seok Park ◽  
Sung-Yeoul Kim ◽  
Hoyeol Lee ◽  
Ju-Sop Lim ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Subcritical Water ◽  
Biological Properties ◽  
Ethanol Solution ◽  
Water Soluble ◽  
Potential Candidate ◽  
High Porosity ◽  
Engineering Applications ◽  
Molecular Weights

For tissue engineering applications, biodegradable scaffolds containing high molecular weights (MW) of collagen and sodium alginate have been developed and characterized. However, the properties of low MW collagen-based scaffolds have not been studied in previous research. This work examined the distinctive properties of low MW collagen-based scaffolds with alginate unmodified and modified by subcritical water. Besides, we developed a facile method to cross-link water-soluble scaffolds using glutaraldehyde in an aqueous ethanol solution. The prepared cross-linked scaffolds showed good structural properties with high porosity (~93%) and high cross-linking degree (50–60%). Compared with collagen (6000 Da)-based scaffolds, collagen (25,000 Da)-based scaffolds exhibited higher stability against collagenase degradation and lower weight loss in phosphate buffer pH 7.4. Collagen (25,000 Da)-based scaffolds with modified alginate tended to improve antioxidant capacity compared with scaffolds containing unmodified alginate. Interestingly, in vitro coagulant activity assay demonstrated that collagen (25,000 Da)-based scaffolds with modified alginate (C25-A63 and C25-A21) significantly reduced the clotting time of human plasma compared with scaffolds consisting of unmodified alginate. Although some further investigations need to be done, collagen (25,000 Da)-based scaffolds with modified alginate should be considered as a potential candidate for tissue engineering applications.

Nano Hydroxyapatite (Nano-Hap): A Potential Bioceramic For Biomedical Applications

2021 ◽  
Vol 06 ◽  
Author(s):  
Varun Saxena ◽  
Lalit Pandey ◽  
T. S. Srivatsan
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Biomedical Applications ◽  
High Surface ◽  
High Surface Area ◽  
Biological Properties ◽  
Engineering Applications ◽  
Biological Responses ◽  
Size And Morphology

Background: Hydroxyapatite (HAp) is one of the most studied biomimic for biomedical applications. Specially, nano-HAp has been utilized for bone tissue engineering various orthopedic applications. HAp possesses various suitable properties such as bioactivity, biodegradability and cell proliferation efficiency for bone tissue engineering applications. Yet, lacks in self-antibacterial activity, high surface area and target efficiency. Results: In this directioon, researchers have focused on exploring the required surface as well as the inherent properties of HAp at the nanoscale. These properties are largely dependent on the composition, size and morphology of the nano-HAp. Hence, nano-HAp has been found to be an excellent candidate with an attractive combination of properties for selection and use in biomedical applications, those required to enhanced biological responses. Further, depending on the type of application, these factors can be tuned to optimize the performance. Conclusion: In this review article, we focus on the chemical structure of HAp and the routes chosen and used for the synthesis of the nano-HAp. The role of various parameters in controlling synthesis at the nanoscale are presented and briefly discussed. In addition, we provide an overview of the various applications for the pristine and doped nano-HAp with recent examples in areas spanning the following: (i) bone tissue engineering applications, (ii) drug delivery applications, (iii) surface coatings, and (iv) scaffolds. The effect of chemical composition on the mechanical properties, surface properties and biological properties are also highlighted. Nano-HAp is found to be highly proficient for its biomedical applications, especially for bone tissue engineering applications. The nano-sized properties enhances the biological responses. The dopant ions that replaces the Ca ion into the hydroxyapatite (HAp) lattice plays a crucial role in its biomedical applications

scholarly journals Carbon nanotubes and their polymeric composites: the applications in tissue engineering

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Boyang Huang
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Tissue Engineering ◽  
Bone Tissue ◽  
Biomedical Applications ◽  
Chemical Properties ◽  
Polymeric Composites ◽  
Biological Properties ◽  
Engineering Applications ◽  
Toxicity Effects

Abstract Carbon nanotubes (CNTs), with unique graphitic structure, superior mechanical, electrical, optical and biological properties, has attracted more and more interests in biomedical applications, including gene/drug delivery, bioimaging, biosensor and tissue engineering. In this review, we focus on the role of CNTs and their polymeric composites in tissue engineering applications, with emphasis on their usages in the nerve, cardiac and bone tissue regenerations. The intrinsic natures of CNTs including their physical and chemical properties are first introduced, explaining the structure effects on CNTs electrical conductivity and various functionalization of CNTs to improve their hydrophobic characteristics. Biosafety issues of CNTs are also discussed in detail including the potential reasons to induce the toxicity and their potential strategies to minimise the toxicity effects. Several processing strategies including solution-based processing, polymerization, melt-based processing and grafting methods are presented to show the 2D/3D construct formations using the polymeric composite containing CNTs. For the sake of improving mechanical, electrical and biological properties and minimising the potential toxicity effects, recent advances using polymer/CNT composite the tissue engineering applications are displayed and they are mainly used in the neural tissue (to improve electrical conductivity and biological properties), cardiac tissue (to improve electrical, elastic properties and biological properties) and bone tissue (to improve mechanical properties and biological properties). Current limitations of CNTs in the tissue engineering are discussed and the corresponded future prospective are also provided. Overall, this review indicates that CNTs are promising “next-generation” materials for future biomedical applications.

Fabrication and characterisation of PCL and PCL/PLA scaffolds for tissue engineering

2014 ◽  
Vol 20 (2) ◽  
pp. 145-156 ◽  
Author(s):  
T. Patrício ◽  
M. Domingos ◽  
A. Gloria ◽  
U. D'Amora ◽  
J.F. Coelho ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Research Work ◽  
Biological Properties ◽  
Poly Lactic Acid ◽  
Solvent Casting ◽  
Melt Blending ◽  
Mixing Process ◽  
Mixing Processes ◽  
Static Compression ◽  
Content Type

Purpose – The main purpose of this research work is to study the effect of poly lactic acid (PLA) addition into poly (e-caprolactone) (PCL) matrices, as well the influence of the mixing process on the morphological, thermal, chemical, mechanical and biological performance of the 3D constructs produced with a novel biomanufacturing device (BioCell Printing). Design/methodology/approach – Two mixing processes are used to prepare PCL/PLA blends, namely melt blending and solvent casting. PCL and PCL/PLA scaffolds are produced via BioCell Printing using a 300-μm nozzle, 0/90° lay down pattern and 350-μm pore size. Several techniques such as scanning electron microscopy (SEM), simultaneous thermal analyzer (STA), nuclear magnetic resonance (NMR), static compression analysis and Alamar BlueTM are used to evaluate scaffold's morphological, thermal, chemical, mechanical and biological properties. Findings – Results show that the addition of PLA to PCL scaffolds strongly improves the biomechanical performance of the constructs. Additionally, polymer blends obtained by solvent casting present better mechanical and biological properties, compared to blends prepared by melt blending. Originality/value – This paper undertakes a detailed study on the effect of the mixing process on the biomechanical properties of PCL/PLA scaffolds. Results will enable to prepare customized PCL/PLA scaffolds for tissue engineering applications with improved biological and mechanical properties, compared to PCL scaffolds alone. Additionally, the accuracy and reproducibility of by the BioCell Printing enables to modulate the micro/macro architecture of the scaffolds enhancing tissue regeneration.

Sintering and Mechanical Properties of Dense Hydroxyapatite Nanocomposites

2010 ◽  
Vol 123-125 ◽  
pp. 771-774 ◽  
Author(s):  
Chanoknan Monthien ◽  
Kanjana Silikulrat ◽  
Gobwute Rujijanagul ◽  
Tawee Tunkasiri ◽  
Sittiporn Punyanitya ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Biological Properties ◽  
Hard Tissue ◽  
Engineering Applications ◽  
Sintering Additive ◽  
Rate Controlled ◽  
Hard Tissue Engineering ◽  
Sintering Method

During recent years, there have been efforts in developing nanocrystalline bioceramics, to enhance their mechanical and biological properties for use in hard tissue engineering applications. In this work, we study the effects of some sintering additive nanopowders dopants on the properties of the sintered HA structures. Calculated quantities of silica nanopowders are incorporate as dopants into dried HA nanopowder. The mixing powders are uniaxially compacted and then sintered at 1200°C by rate-controlled sintering method in air. Compositional, microstructural, morphological and mechanical characterizations are carried out on sintered HA samples.

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