scholarly journals Macroporous chitosan/methoxypoly(ethylene glycol) based cryosponges with unique morphology for tissue engineering applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pradeep Kumar ◽  
Viness Pillay ◽  
Yahya E. Choonara

AbstractThree-dimensional porous scaffolds are widely employed in tissue engineering and regenerative medicine for their ability to carry bioactives and cells; and for their platform properties to allow for bridging-the-gap within an injured tissue. This study describes the effect of various methoxypolyethylene glycol (mPEG) derivatives (mPEG (-OCH3 functionality), mPEG-aldehyde (mPEG-CHO) and mPEG-acetic acid (mPEG-COOH)) on the morphology and physical properties of chemically crosslinked, semi-interpenetrating polymer network (IPN), chitosan (CHT)/mPEG blend cryosponges. Physicochemical and molecular characterization revealed that the –CHO and –COOH functional groups in mPEG derivatives interacted with the –NH2 functionality of the chitosan chain. The distinguishing feature of the cryosponges was their unique morphological features such as fringe thread-, pebble-, curved quartz crystal-, crystal flower-; and canyon-like structures. The morphological data was well corroborated by the image processing data and physisorption curves corresponding to Type II isotherm with open hysteresis loops. Functionalization of mPEG had no evident influence on the macro-mechanical properties of the cryosponges but increased the matrix strength as determined by the rheomechanical analyses. The cryosponges were able to deliver bioactives (dexamethasone and curcumin) over 10 days, showed varied matrix degradation profiles, and supported neuronal cells on the matrix surface. In addition, in silico simulations confirmed the compatibility and molecular stability of the CHT/mPEG blend compositions. In conclusion, the study confirmed that significant morphological variations may be induced by minimal functionalization and crosslinking of biomaterials.

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22544-22555
Author(s):  
Atefeh Safaei-Yaraziz ◽  
Shiva Akbari-Birgani ◽  
Nasser Nikfarjam

The interlacing of biopolymers and synthetic polymers is a promising strategy to fabricate hydrogel-based tissue scaffolds to biomimic a natural extracellular matrix for cell growth.


Marine Drugs ◽  
2018 ◽  
Vol 16 (12) ◽  
pp. 484 ◽  
Author(s):  
Xiaowei Zhang ◽  
Gyeong Kim ◽  
Min Kang ◽  
Jung Lee ◽  
Jeong Seo ◽  
...  

Biologically active materials from marine sources have been receiving increasing attention as they are free from the transmissible diseases and religious restrictions associated with the use of mammalian resources. Among various other biomaterials from marine sources, alginate and fish gelatin (f-gelatin), with their inherent bioactivity and physicochemical tunability, have been studied extensively and applied in various biomedical fields such as regenerative medicine, tissue engineering, and pharmaceutical products. In this study, by using alginate and f-gelatin’s chemical derivatives, we developed a marine-based interpenetrating polymer network (IPN) hydrogel consisting of alginate and f-gelatin methacryloyl (f-GelMA) networks via physical and chemical crosslinking methods, respectively. We then evaluated their physical properties (mechanical strength, swelling degree, and degradation rate) and cell behavior in hydrogels. Our results showed that the alginate/f-GelMA hydrogel displayed unique physical properties compared to when alginate and f-GelMA were used separately. These properties included high mechanical strength, low swelling and degradation rate, and an increase in cell adhesive ability. Moreover, for the first time, we introduced and optimized the application of alginate/f-GelMA hydrogel in a three-dimensional (3D) bioprinting system with high cell viability, which breaks the restriction of their utilization in tissue engineering applications and suggests that alginate/f-GelMA can be utilized as a novel bioink to broaden the uses of marine products in biomedical fields.


2021 ◽  
Vol 2021 ◽  
pp. 1-20 ◽  
Author(s):  
Dhinakaran Veeman ◽  
M. Swapna Sai ◽  
P. Sureshkumar ◽  
T. Jagadeesha ◽  
L. Natrayan ◽  
...  

As a technique of producing fabric engineering scaffolds, three-dimensional (3D) printing has tremendous possibilities. 3D printing applications are restricted to a wide range of biomaterials in the field of regenerative medicine and tissue engineering. Due to their biocompatibility, bioactiveness, and biodegradability, biopolymers such as collagen, alginate, silk fibroin, chitosan, alginate, cellulose, and starch are used in a variety of fields, including the food, biomedical, regeneration, agriculture, packaging, and pharmaceutical industries. The benefits of producing 3D-printed scaffolds are many, including the capacity to produce complicated geometries, porosity, and multicell coculture and to take growth factors into account. In particular, the additional production of biopolymers offers new options to produce 3D structures and materials with specialised patterns and properties. In the realm of tissue engineering and regenerative medicine (TERM), important progress has been accomplished; now, several state-of-the-art techniques are used to produce porous scaffolds for organ or tissue regeneration to be suited for tissue technology. Natural biopolymeric materials are often better suited for designing and manufacturing healing equipment than temporary implants and tissue regeneration materials owing to its appropriate properties and biocompatibility. The review focuses on the additive manufacturing of biopolymers with significant changes, advancements, trends, and developments in regenerative medicine and tissue engineering with potential applications.


2019 ◽  
Vol 4 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Reetu Prabhakar ◽  
Devendra Kumar

Background: The superabsorbent polymers based conducting hydrogel such as polyaniline impregnated polyacrylate-starch hydrogel were synthesized via two -steps interpenetrating polymer network process. In the present work instead of using a synthetic polymer of acrylamide, a biodegradable polymer such as starch has been used with polyacrylate superabsorbent polymer. The main attempt of this work is to analyze the electrical conductivity of resulting hydrogel at varying concentrations of crosslinker, initiator, monomer, and a copolymer for improving the properties of synthesized hydrogel and elaborating the diversity of its utilization. Methods: The polymerization of aniline was performed through the absorption of aniline monomer into the polymer matrix followed by the addition of initiator/dopant solution. The morphological and structural analysis and thermal stability of the synthesized hydrogel were studied using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy and thermogravimetric analysis (TGA), respectively. The swelling behaviour of the synthesized hydrogel was performed in a different medium. Results: Electrical conductivity data of polyacrylate-starch/polyaniline (PAANa-starch/PANI) were compared from polyacrylate-co-polyacrylamide/polyaniline P(AANa-co-AM)/PANI hydrogel, which revealed that polyacrylate-starch/polyaniline shows higher conductivity than polyacrylate-co-polyacrylamide/ polyaniline conducting hydrogel. Maximum swelling of the synthesized hydrogel was reported in the basic medium. Conclusion: It is observed that the addition of starch into the matrix significantly improved the overall properties of hydrogel. The polymerization of aniline was done in-situ with the absorption of aniline monomer into the PAANa-starch polymer matrix followed by soaking in an initiator/dopant solution. The XRD pattern of PAANa-starch/PANI showed a broad peak at 22.8o while no peak was observed in the PAANa-starch gel, implying that PAANa-starch/PANI has a crystalline and more ordered structure. PAANa-starch/PANI has higher conductivity than the P(AANa-co-AM)/PANI hydrogel. This enhanced electrical conductivity in case of PAANa-starch/PANI hydrogel could be due to the more crosslink points of synthetic polymer polyacrylamide between PAANa-PANI hydrogel.


2019 ◽  
Vol 52 (1) ◽  
pp. 29-52
Author(s):  
Jagesh Kumar Ranjan ◽  
Sudipta Goswami

Kenaf fibre-reinforced vinyl ester (VE)/polyurethane (PU) interpenetrating polymer network (IPN)-based composites were made by hand lay-up technique. The kenaf bast fibre was chemically treated with 3, 6 and 9% vinyl silane. Treated fibres were characterized in terms of crystallinity, mechanical strength, density, thermal property and morphology. In comparison with the untreated fibre, 6% silane-treated fibres showed 25.4% higher % crystallinity, 66.9% increase in modulus elasticity and 604.2% increase in tenacity. Comparison of the pure VE with VE/PU IPN showed that the IPN had 3.3% lower modulus but 26.4% higher toughness than the former. Composites based on pure VE matrix and VE/PU IPN matrix were manufactured with the variation of untreated and treated fibre loading as 15, 20, 25, 30, 35 and 40 wt%. Novelty of this work lies in the modification of both the fibre surface and the matrix system simultaneously with the aim of increasing the adhesion between the fibre surface and matrix material of the composite. Composites with untreated fibres showed poor strength compared to that with modified fibres having corresponding compositions. IPN-based composites, with 35 wt% silane-treated fibre, showed improvement in tensile modulus by 16.61% and flexural modulus by 6.35% than pure VE-based composites with corresponding fibre loading.


2019 ◽  
Vol 11 (40) ◽  
pp. 36359-36370 ◽  
Author(s):  
Yaqiang Li ◽  
Yanqun Liu ◽  
Xiaowei Xun ◽  
Wei Zhang ◽  
Yong Xu ◽  
...  

2011 ◽  
Vol 493-494 ◽  
pp. 826-831
Author(s):  
A.C.B.M. Fook ◽  
Thiago Bizerra Fideles ◽  
R.C. Barbosa ◽  
G.T.F.S. Furtado ◽  
G.Y.H. Sampaio ◽  
...  

The application of a hybrid composite consisting of biopolymer and calcium phosphate, similar morphology and properties of natural bone, may be a way to solve the problem of the fragility of ceramics without reducing its mechanical properties, retaining the properties of biocompatibility and high bioactivity. This work aims at the preparation and characterization of three-dimensional scaffolds composite HA / biopolymers (chitosan and gelatin). The freeze-drying technique was employed in this study to obtain these frameworks and partial results showed the effectiveness of this method. This involved the study of structural, chemical and morphological frameworks, in order to direct the research suggested the application. The X Ray Diffraction (XRD) and infrared spectroscopy and Fourier transform (FTIR) results confirmed the formation of hydroxyapatite (HA) phase and the presence of characteristic bands of HA and biopolymers in all compositions. The microstructure of the scaffolds study conducted by Scanning Electron Microscopy (SEM) revealed the formation of longitudinally oriented microchannels with interconnected pores. In all compositions the porous scaffolds showed varying sizes and mostly larger than 100μm, and is therefore considered materials with potential for application in bone tissue engineering.


Author(s):  
Jin-Hyung Shim ◽  
Jong Young Kim ◽  
Kyung Shin Kang ◽  
Jung Kyu Park ◽  
Sei Kwang Hahn ◽  
...  

Tissue engineering is an interdisciplinary field that focuses on restoring and repairing tissues or organs. Cells, scaffolds, and biomolecules are recognized as three main components of tissue engineering. Solid freeform fabrication (SFF) technology is required to fabricate three-dimensional (3D) porous scaffolds to provide a 3D environment for cellular activity. SFF technology is especially advantageous for achieving a fully interconnected, porous scaffold. Bone morphogenic protein-2 (BMP-2), an important biomolecule, is widely used in bone tissue engineering to enhance bone regeneration activity. However, methods for the direct incorporation of intact BMP-2 within 3D scaffolds are rare. In this work, 3D porous scaffolds with poly(lactic-co-glycolic acid) chemically grafted hyaluronic acid (HA-PLGA), in which intact BMP-2 was directly encapsulated, were successfully fabricated using SFF technology. BMP-2 was previously protected by poly(ethylene glycol) (PEG), and the BMP-2/PEG complex was incorporated in HA-PLGA using an organic solvent. The HAPLGA/PEG/BMP-2 mixture was dissolved in chloroform and deposited via a multi-head deposition system (MHDS), one type of SFF technology, to fabricate a scaffold for tissue engineering. An additional air blower system and suction were installed in the MHDS for the solvent-based fabrication method. An in vitro evaluation of BMP-2 release was conducted, and prolonged release of intact BMP-2, for up to 28 days, was confirmed. After confirmation of advanced proliferation of pre osteoblasts, a superior differentiation effect of the HA-PLGA/PEG/BMP-2 scaffold was validated by measuring high expression levels of bone-specific markers, such as alkaline phosphatase (ALP) and osteocalcin (OC). We show that our solvent-based fabrication is a non-toxic method for restoring cellular activity. Moreover, the HAPLGA/PEG/BMP-2 scaffold was effective for bone regeneration.


2019 ◽  
Vol 10 ◽  
pp. 204173141982643 ◽  
Author(s):  
Chinmaya Mahapatra ◽  
Jung-Ju Kim ◽  
Jung-Hwan Lee ◽  
Guang-Zhen Jin ◽  
Jonathan C Knowles ◽  
...  

Bone/cartilage interfacial tissue engineering needs to satisfy the differential properties and architectures of the osteochondral region. Therefore, biphasic or multiphasic scaffolds that aim to mimic the gradient hierarchy are widely used. Here, we find that two differently structured (topographically) three-dimensional scaffolds, namely, “dense” and “nanofibrous” surfaces, show differential stimulation in osteo- and chondro-responses of cells. While the nanofibrous scaffolds accelerate the osteogenesis of mesenchymal stem cells, the dense scaffolds are better in preserving the phenotypes of chondrocytes. Two types of porous scaffolds, generated by a salt-leaching method combined with a phase-separation process using the poly(lactic acid) composition, had a similar level of porosity (~90%) and pore size (~150 μm). The major difference in the surface nanostructure led to substantial changes in the surface area and water hydrophilicity (nanofibrous ≫ dense); as a result, the nanofibrous scaffolds increased the cell-to-matrix adhesion of mesenchymal stem cells significantly while decreasing the cell-to-cell contracts. Importantly, the chondrocytes, when cultured on nanofibrous scaffolds, were prone to lose their phenotype, including reduced chondrogenic expressions (SOX-9, collagen type II, and Aggrecan) and glycosaminoglycan content, which was ascribed to the enhanced cell–matrix adhesion with reduced cell–cell contacts. On the contrary, the osteogenesis of mesenchymal stem cells was significantly accelerated by the improved cell-to-matrix adhesion, as evidenced in the enhanced osteogenic expressions (RUNX2, bone sialoprotein, and osteopontin) and cellular mineralization. Based on these findings, we consider that the dense scaffold is preferentially used for the chondral-part, whereas the nanofibrous structure is suitable for osteo-part, to provide an optimal biphasic matrix environment for osteochondral tissue engineering.


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