scholarly journals Competitive Biosynthesis of Bacterial Alginate Using Azotobacter vinelandii 12 for Tissue Engineering Applications

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 131
Author(s):  
Andrei A. Dudun ◽  
Elizaveta A. Akoulina ◽  
Vsevolod A. Zhuikov ◽  
Tatiana K. Makhina ◽  
Vera V. Voinova ◽  
...  

This study investigated the effect of various cultivation conditions (sucrose/phosphate concentrations, aeration level) on alginate biosynthesis using the bacterial producing strain Azotobacter vinelandii 12 by the full factorial design (FFD) method and physicochemical properties (e.g., rheological properties) of the produced bacterial alginate. We demonstrated experimentally the applicability of bacterial alginate for tissue engineering (the cytotoxicity testing using mesenchymal stem cells (MSCs)). The isolated synthesis of high molecular weight (Mw) capsular alginate with a high level of acetylation (25%) was achieved by FFD method under a low sucrose concentration, an increased phosphate concentration, and a high aeration level. Testing the viscoelastic properties and cytotoxicity showed that bacterial alginate with a maximal Mw (574 kDa) formed the densest hydrogels (which demonstrated relatively low cytotoxicity for MSCs in contrast to bacterial alginate with low Mw). The obtained data have shown promising prospects in controlled biosynthesis of bacterial alginate with different physicochemical characteristics for various biomedical applications including tissue engineering.

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3302
Author(s):  
Antony V. Samrot ◽  
Sree K. Samanvitha ◽  
N. Shobana ◽  
Emilin R. Renitta ◽  
Puvanesvaran Senthil Kumar ◽  
...  

Polyhydroxyalkanoates (PHAs) are storage granules found in bacteria that are essentially hydroxy fatty acid polyesters. PHA molecules appear in variety of structures, and amongst all types of PHAs, polyhydroxybutyrate (PHB) is used in versatile fields as it is a biodegradable, biocompatible, and ecologically safe thermoplastic. The unique physicochemical characteristics of these PHAs have made them applicable in nanotechnology, tissue engineering, and other biomedical applications. In this review, the optimization, extraction, and characterization of PHAs are described. Their production and application in nanotechnology are also portrayed in this review, and the precise and various production methods of PHA-based nanoparticles, such as emulsion solvent diffusion, nanoprecipitation, and dialysis are discussed. The characterization techniques such as UV-Vis, FTIR, SEM, Zeta Potential, and XRD are also elaborated.


2019 ◽  
Vol 26 (38) ◽  
pp. 6834-6850 ◽  
Author(s):  
Mohammad Omaish Ansari ◽  
Kalamegam Gauthaman ◽  
Abdurahman Essa ◽  
Sidi A. Bencherif ◽  
Adnan Memic

: Nanobiotechnology has huge potential in the field of regenerative medicine. One of the main drivers has been the development of novel nanomaterials. One developing class of materials is graphene and its derivatives recognized for their novel properties present on the nanoscale. In particular, graphene and graphene-based nanomaterials have been shown to have excellent electrical, mechanical, optical and thermal properties. Due to these unique properties coupled with the ability to tune their biocompatibility, these nanomaterials have been propelled for various applications. Most recently, these two-dimensional nanomaterials have been widely recognized for their utility in biomedical research. In this review, a brief overview of the strategies to synthesize graphene and its derivatives are discussed. Next, the biocompatibility profile of these nanomaterials as a precursor to their biomedical application is reviewed. Finally, recent applications of graphene-based nanomaterials in various biomedical fields including tissue engineering, drug and gene delivery, biosensing and bioimaging as well as other biorelated studies are highlighted.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 261
Author(s):  
Orlando Donoso-González ◽  
Lucas Lodeiro ◽  
Álvaro E. Aliaga ◽  
Miguel A. Laguna-Bercero ◽  
Soledad Bollo ◽  
...  

Gold nanostars (AuNSs) exhibit modulated plasmon resonance and have a high SERS enhancement factor. However, their low colloidal stability limits their biomedical application as a nanomaterial. Cationic β-cyclodextrin-based polymer (CCD/P) has low cytotoxicity, can load and transport drugs more efficiently than the corresponding monomeric form, and has an appropriate cationic group to stabilize gold nanoparticles. In this work, we functionalized AuNSs with CCD/P to load phenylethylamine (PhEA) and piperine (PIP) and evaluated SERS-based applications of the products. PhEA and PIP were included in the polymer and used to functionalize AuNSs, forming a new AuNS-CCD/P-PhEA-PIP nanosystem. The system was characterized by UV–VIS, IR, and NMR spectroscopy, TGA, SPR, DLS, zeta potential analysis, FE-SEM, and TEM. Additionally, Raman optical activity, SERS analysis and complementary theoretical studies were used for characterization. Minor adjustments increased the colloidal stability of AuNSs. The loading capacity of the CCD/P with PhEA-PIP was 95 ± 7%. The physicochemical parameters of the AuNS-CCD/P-PhEA-PIP system, such as size and Z potential, are suitable for potential biomedical applications Raman and SERS studies were used to monitor PhEA and PIP loading and their preferential orientation upon interaction with the surface of AuNSs. This unique nanomaterial could be used for simultaneous drug loading and SERS-based detection.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1631
Author(s):  
Mariangela Guastaferro ◽  
Ernesto Reverchon ◽  
Lucia Baldino

A comparative analysis concerning bio-based gels production, to be used for tissue regeneration, has been performed in this review. These gels are generally applied as scaffolds in the biomedical field, thanks to their morphology, low cytotoxicity, and high biocompatibility. Focusing on the time interval 2015–2020, the production of 3D scaffolds of alginate, chitosan and agarose, for skin and bone regeneration, has mainly been investigated. Traditional techniques are critically reviewed to understand their limitations and how supercritical CO2-assisted processes could overcome these drawbacks. In particular, even if freeze-drying represents the most widespread drying technique used to produce polysaccharide-based cryogels, supercritical CO2-assisted drying effectively allows preservation of the nanoporous aerogel structure and removes the organic solvent used for gel preparation. These characteristics are essential for cell adhesion and proliferation.


2021 ◽  
Author(s):  
Marissa Morales-Moctezuma ◽  
Sebastian G Spain

Nanogels have emerged as innovative platforms for numerous biomedical applications including gene and drug delivery, biosensors, imaging, and tissue engineering. Polymerisation-induced thermal self-assembly (PITSA) has been shown to be suitable...


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 412
Author(s):  
Sam Swingler ◽  
Abhishek Gupta ◽  
Hazel Gibson ◽  
Marek Kowalczuk ◽  
Wayne Heaselgrave ◽  
...  

Bacterial cellulose (BC) is an extracellular polymer produced by Komagateibacter xylinus, which has been shown to possess a multitude of properties, which makes it innately useful as a next-generation biopolymer. The structure of BC is comprised of glucose monomer units polymerised by cellulose synthase in β-1-4 glucan chains which form uniaxially orientated BC fibril bundles which measure 3–8 nm in diameter. BC is chemically identical to vegetal cellulose. However, when BC is compared with other natural or synthetic analogues, it shows a much higher performance in biomedical applications, potable treatment, nano-filters and functional applications. The main reason for this superiority is due to the high level of chemical purity, nano-fibrillar matrix and crystallinity. Upon using BC as a carrier or scaffold with other materials, unique and novel characteristics can be observed, which are all relatable to the features of BC. These properties, which include high tensile strength, high water holding capabilities and microfibrillar matrices, coupled with the overall physicochemical assets of bacterial cellulose makes it an ideal candidate for further scientific research into biopolymer development. This review thoroughly explores several areas in which BC is being investigated, ranging from biomedical applications to electronic applications, with a focus on the use as a next-generation wound dressing. The purpose of this review is to consolidate and discuss the most recent advancements in the applications of bacterial cellulose, primarily in biomedicine, but also in biotechnology.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1269
Author(s):  
Gareth Sheppard ◽  
Karl Tassenberg ◽  
Bogdan Nenchev ◽  
Joel Strickland ◽  
Ramy Mesalam ◽  
...  

In tissue engineering, scaffolds are a key component that possess a highly elaborate pore structure. Careful characterisation of such porous structures enables the prediction of a variety of large-scale biological responses. In this work, a rapid, efficient, and accurate methodology for 2D bulk porous structure analysis is proposed. The algorithm, “GAKTpore”, creates a morphology map allowing quantification and visualisation of spatial feature variation. The software achieves 99.6% and 99.1% mean accuracy for pore diameter and shape factor identification, respectively. There are two main algorithm novelties within this work: (1) feature-dependant homogeneity map; (2) a new waviness function providing insights into the convexity/concavity of pores, important for understanding the influence on cell adhesion and proliferation. The algorithm is applied to foam structures, providing a full characterisation of a 10 mm diameter SEM micrograph (14,784 × 14,915 px) with 190,249 pores in ~9 min and has elucidated new insights into collagen scaffold formation by relating microstructural formation to the bulk formation environment. This novel porosity characterisation algorithm demonstrates its versatility, where accuracy, repeatability, and time are paramount. Thus, GAKTpore offers enormous potential to optimise and enhance scaffolds within tissue engineering.


Author(s):  
Aida Mekhoukhe ◽  
Nacer Mohellebi ◽  
Tayeb Mohellebi ◽  
Leila Deflaoui-Abdelfettah ◽  
Sonia Medouni-Adrar ◽  
...  

OBJECTIVE: the present work proposed to extract Locust Bean Gum (LBG) from Algerian carob fruits, evaluate physicochemical and rheological properties (solubility). It aimed also to develop different formulations of strawberry jams with a mixture of LBG and pectin in order to obtain a product with a high sensory acceptance. METHODS: the physicochemical characteristics of LBG were assessed. The impact of temperature on solubility was also studied. The physical and the sensory profile and acceptance of five Jams were evaluated. RESULTS: composition results revealed that LBG presented a high level of carbohydrate but low concentrations of fat and ash. The LBG was partially cold-water-soluble (∼62% at 25°C) and needed heating to reach a higher solubility value (∼89% at 80 °C). Overall, the sensorial acceptances decreased in jams J3 which was formulated with 100% pectin and commercial one (J5). The external preference map explained that most consumers were located to the right side of the map providing evidence that most samples appreciated were J4 and J2 (rate of 80–100%). CONCLUSION: In this investigation, the LBG was used successfully in the strawberry jam’s formulation.


Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Traian V. Chirila

Fibroin is a fibrous protein that can be conveniently isolated from the silk cocoons produced by the larvae of Bombyx mori silk moth. In its form as a hydrogel, Bombyx mori silk fibroin (BMSF) has been employed in a variety of biomedical applications. When used as substrates for biomaterial-cells constructs in tissue engineering, the oxygen transport characteristics of the BMSF membranes have proved so far to be adequate. However, over the past three decades the BMSF hydrogels have been proposed episodically as materials for the manufacture of contact lenses, an application that depends on substantially elevated oxygen permeability. This review will show that the literature published on the oxygen permeability of BMSF is both limited and controversial. Additionally, there is no evidence that contact lenses made from BMSF have ever reached commercialization. The existing literature is discussed critically, leading to the conclusion that BMSF hydrogels are unsuitable as materials for contact lenses, while also attempting to explain the scarcity of data regarding the oxygen permeability of BMSF. To the author’s knowledge, this review covers all publications related to the topic.


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