scholarly journals GAKTpore: Stereological Characterisation Methods for Porous Foams in Biomedical Applications

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1269
Author(s):  
Gareth Sheppard ◽  
Karl Tassenberg ◽  
Bogdan Nenchev ◽  
Joel Strickland ◽  
Ramy Mesalam ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Biomedical Applications ◽  
Large Scale ◽  
Collagen Scaffold ◽  
Porous Structures ◽  
Tissue Engineering Scaffolds ◽  
Biological Responses ◽  
Sem Micrograph ◽  
Cell Adhesion And Proliferation ◽  
Characterisation Methods

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.

scholarly journals THREE-DIMENSIONAL NANOCOMPOSITE SCAFFOLDS FOR BONE TISSUE ENGINEERING: FROM DESIGN TO APPLICATION

Nano LIFE ◽  
2012 ◽  
Vol 02 (01) ◽  
pp. 1250005 ◽  
Author(s):  
BIN DUAN ◽  
MIN WANG ◽  
WILLIAM W. LU
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Rabbit Model ◽  
Bone Morphogenetic Protein 2 ◽  
Human Umbilical Cord ◽  
Porous Structures ◽  
Tissue Engineering Scaffolds ◽  
Surface Modified ◽  
Nanocomposite Scaffolds

Selective laser sintering (SLS), a rapid prototyping technology, was investigated for producing bone tissue engineering scaffolds. Completely biodegradable osteoconductive calcium phosphate (Ca-P)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) scaffolds were successfully fabricated via SLS using Ca-P/PHBV nanocomposite microspheres. In the SLS manufacturing route, the architecture of tissue engineering scaffolds (pore shape, size, interconnectivity, etc.) can be designed and the sintering process can be optimized for obtaining scaffolds with desirable porous structures and mechanical properties. SLS was also shown to be very effective in producing highly complex porous structures using nanocomposite microspheres. To render SLS-formed Ca-P/PHBV scaffolds osteoinductive, recombinant human bone morphogenetic protein-2 (rhBMP-2) could be loaded onto the scaffolds. For achieving a controlled release of rhBMP-2 from scaffolds, surface modification of Ca-P/PHBV scaffolds by gelatin entrapment and heparin immobilization was needed. The immobilized heparin provided binding affinity for rhBMP-2. Surface modified Ca-P/PHBV nanocomposite scaffolds loaded with rhBMP-2 enhanced the proliferation of human umbilical cord derived mesenchymal stem cells (hUCMSCs) and also their alkaline phosphatase activity. In in vivo experiments using a rabbit model, surface modified Ca-P/PHBV nanocomposite scaffolds loaded with rhBMP-2 promoted ectopic bone formation, exhibiting their osteoinductivity. The strategy of combining advanced scaffold fabrication, nanocomposite material, and controlled growth factor delivery is promising for bone tissue regeneration.

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 Development of 3D Bioactive Nanocomposite Scaffolds Made from Gelatin and Nano Bioactive Glass for Biomedical Applications

2010 ◽  
Vol 19 (2) ◽  
pp. 096369351001900 ◽  
Author(s):  
M. Mozafari ◽  
F. Moztarzadeh ◽  
M. Rabiee ◽  
M. Azami ◽  
N. Nezafati ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bioactive Glass ◽  
Biomedical Applications ◽  
Cell Attachment ◽  
Tissue Engineering Scaffolds ◽  
Study Results ◽  
Nanocomposite Scaffold ◽  
Nanocomposite Scaffolds ◽  
First Time

In this research, macroporous, mechanically competent and bioactive nanocomposite scaffolds have been fabricated from cross-linked gelatine (Gel) and nano bioactive glass (nBG) through layer solvent casting combined with freeze-drying and lamination techniques. This study has developed a new composition to produce a new bioactive nanocomposite which is porous with interconnected microstructure, pore sizes are 200-500 μm, porosity are 72%-86%. Also, we have reported formation of chemical bonds between nBG and Gel for the first time. Finally, the in vitro cytocompatability of the scaffolds was assessed using MTT assay and cell attachment study. Results indicated no sign of toxicity and cells found to be attached to the pore walls offered by the scaffolds. These results suggested that the developed nanocomposite scaffold possess the prerequisites for bone tissue engineering scaffolds and it can be used for tissue engineering applications.

scholarly journals Vibrio Proteases for Biomedical Applications: Modulating the Proteolytic Secretome of V. alginolyticus and V. parahaemolyticus for Improved Enzymes Production

2019 ◽  
Vol 7 (10) ◽  
pp. 387 ◽  
Author(s):  
Monica Salamone ◽  
Aldo Nicosia ◽  
Giulio Ghersi ◽  
Marcello Tagliavia
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Biomedical Applications ◽  
Large Scale ◽  
Proteolytic Enzymes ◽  
High Specificity ◽  
Growth Conditions ◽  
Culture Conditions ◽  
Scale Production ◽  
Biological Responses ◽  
Large Scale Production

Proteolytic enzymes are of great interest for biotechnological purposes, and their large-scale production, as well as the discovery of strains producing new molecules, is a relevant issue. Collagenases are employed for biomedical and pharmaceutical purposes. The high specificity of collagenase-based preparations toward the substrate strongly relies on the enzyme purity. However, the overall activity may depend on the cooperation with other proteases, the presence of which may be essential for the overall enzymatic activity, but potentially harmful for cells and tissues. Vibrios produce some of the most promising bacterial proteases (including collagenases), and their exo-proteome includes several enzymes with different substrate specificities, the production and relative abundances of which strongly depend on growth conditions. We evaluated the effects of different media compositions on the proteolytic exo-proteome of Vibrio alginolyticus and its closely relative Vibrio parahaemolyticus, in order to improve the overall proteases production, as well as the yield of the desired enzymes subset. Substantial biological responses were achieved with all media, which allowed defining culture conditions for targeted improvement of selected enzyme classes, besides giving insights in possible regulatory mechanisms. In particular, we focused our efforts on collagenases production, because of the growing biotechnological interest due to their pharmaceutical/biomedical applications.

scholarly journals Antibacterial cellulose-based aerogels for wound healing application: A review

2020 ◽  
Vol 7 (10) ◽  
pp. 4032-4040
Author(s):  
Esam Bashir Yahya ◽  
Marwa Mohammed Alzalouk ◽  
Khalifa A. Alfallous ◽  
Abdullah F. Abogmaza
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Wound Healing ◽  
Wound Dressing ◽  
Biomedical Applications ◽  
Inorganic Materials ◽  
Medical Applications ◽  
Tissue Engineering Scaffolds

Aerogels have been steadily developed since its first invention to become one of the most promising materials for various medical and non-medical applications. It has been prepared from organic and inorganic materials, in pure forms or composites. Cellulose-based aerogels are considered one of the promising materials in biomedical applications due to their availability, degradability, biocompatibility and non-cytotoxicity compared to conventional silica or metal-based aerogels. The unique properties of such materials permit their utilization in drug delivery, biosensing, tissue engineering scaffolds, and wound dressing. This review presents a summary of aerogel development as well as the properties and applications of aerogels. Herein, we further discuss the recent works pertaining to utilization of cellulose-based aerogels for antibacterial delivery.

scholarly journals Modeling and Simulation of a Selective Laser Foaming Process for Fabrication of Microliter Tissue Engineering Scaffolds

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
JinGyu Ock ◽  
Wei Li
Keyword(s):  
Tissue Engineering ◽  
Laser Power ◽  
Biomedical Applications ◽  
Processing Parameters ◽  
Tissue Engineering Scaffolds ◽  
Element Analysis ◽  
Laser Absorption ◽  
Fea Model ◽  
Foaming Process ◽  
And Control

Selective laser foaming is a novel process that combines solid-state foaming and laser ablation to fabricate an array of microliter tissue engineering scaffolds on a polymeric chip for biomedical applications. In this study, a finite element analysis (FEA) model is developed to investigate the effect of laser processing parameters. Experimental results with biodegradable polylactic acid (PLA) were used for validation. It is found that foaming always occurs before ablation, and once it occurs, the temperature increases dramatically due to an enhanced laser absorption effect of the porous structure. The geometry of the fabricated scaffolds can be controlled by laser parameters. While the depth of scaffolds can be controlled by laser power and lasing time, the diameter is more effectively controlled by the laser power. The model developed in this study can be used to optimize and control the selective foaming process.

scholarly journals Triblock Copolymers Based on ε-Caprolactone and Trimethylene Carbonate for the 3D Printing of Tissue Engineering Scaffolds

2017 ◽  
Vol 40 (4) ◽  
pp. 176-184 ◽  
Author(s):  
Aysun Güney ◽  
Jos Malda ◽  
Wouter J.A. Dhert ◽  
Dirk W. Grijpma
Keyword(s):  
Tissue Engineering ◽  
Glass Transition ◽  
3D Printing ◽  
Melting Temperature ◽  
Triblock Copolymers ◽  
Ethylene Carbonate ◽  
Porous Structures ◽  
Trimethylene Carbonate ◽  
Tissue Engineering Scaffolds ◽  
Slow Cooling

Background Biodegradable PCL- b-PTMC- b-PCL triblock copolymers based on trimethylene carbonate (TMC) and ε-caprolactone (CL) were prepared and used in the 3D printing of tissue engineering scaffolds. Triblock copolymers of various molecular weights containing equal amounts of TMC and CL were prepared. These block copolymers combine the low glass transition temperature of amorphous PTMC (approximately -20°C) and the semi-crystallinity of PCL (glass transition approximately -60°C and melting temperature approximately 60°C). Methods PCL- b-PTMC- b-PCL triblock copolymers were synthesized by sequential ring opening polymerization (ROP) of TMC and ε-CL. From these materials, films were prepared by solvent casting and porous structures were prepared by extrusion-based 3D printing. Results Films prepared from a polymer with a relatively high molecular weight of 62 kg/mol had a melting temperature of 58°C and showed tough and resilient behavior, with values of the elastic modulus, tensile strength and elongation at break of approximately 120 MPa, 16 MPa and 620%, respectively. Porous structures were prepared by 3D printing. Ethylene carbonate was used as a crystalizable and water-extractable solvent to prepare structures with microporous strands. Solutions, containing 25 wt% of the triblock copolymer, were extruded at 50°C then cooled at different temperatures. Slow cooling at room temperature resulted in pores with widths of 18 ± 6 μm and lengths of 221 ± 77 μm, rapid cooling with dry ice resulted in pores with widths of 13 ± 3 μm and lengths of 58 ± 12 μm. These PCL- b-PTMC- b-PCL triblock copolymers processed into porous structures at relatively low temperatures may find wide application as designed degradable tissue engineering scaffolds. Conclusions In this preliminary study we prepared biodegradable triblock copolymers based on 1,3-trimethylene carbonate and ε-caprolactone and assessed their physical characteristics. Furthermore, we evaluated their potential as melt-processable thermoplastic elastomeric biomaterials in 3D printing of tissue engineering scaffolds.

scholarly journals Microbial-Derived Polyhydroxyalkanoate-Based Scaffolds for Bone Tissue Engineering: Biosynthesis, Properties, and Perspectives

2021 ◽  
Vol 9 ◽  
Author(s):  
Jian Li ◽  
Xu Zhang ◽  
Anjaneyulu Udduttula ◽  
Zhi Shan Fan ◽  
Jian Hai Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Biomedical Applications ◽  
Large Scale ◽  
Lower Cost ◽  
Culture Conditions ◽  
Manufacturing Technologies ◽  
Insight Into

Polyhydroxyalkanoates (PHAs) are a class of structurally diverse natural biopolyesters, synthesized by various microbes under unbalanced culture conditions. PHAs as biomedical materials have been fabricated in various forms to apply to tissue engineering for the past years due to their excellent biodegradability, inherent biocompatibility, modifiable mechanical properties, and thermo-processability. However, there remain some bottlenecks in terms of PHA production on a large scale, the purification process, mechanical properties, and biodegradability of PHA, which need to be further resolved. Therefore, scientists are making great efforts via synthetic biology and metabolic engineering tools to improve the properties and the product yields of PHA at a lower cost for the development of various PHA-based scaffold fabrication technologies to widen biomedical applications, especially in bone tissue engineering. This review aims to outline the biosynthesis, structures, properties, and the bone tissue engineering applications of PHA scaffolds with different manufacturing technologies. The latest advances will provide an insight into future outlooks in PHA-based scaffolds for bone tissue engineering.

Sign in / Sign up

Export Citation Format

Share Document