scholarly journals Biodegradable Chitosan-graft-Poly(l-lactide) Copolymers For Bone Tissue Engineering

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 316 ◽  
Author(s):  
Maria Kaliva ◽  
Anthie Georgopoulou ◽  
Dimitrios A. Dragatogiannis ◽  
Costas A. Charitidis ◽  
Maria Chatzinikolaidou ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Culture ◽  
Mechanical Stability ◽  
Young Modulus ◽  
Biological Properties ◽  
Design And Synthesis ◽  
Copolymer Films ◽  
Strong Adhesion ◽  
Lactide Copolymers

The design and synthesis of new biomaterials with adjustable physicochemical and biological properties for tissue engineering applications have attracted great interest. In this work, chitosan-graft-poly(l-lactide) (CS-g-PLLA) copolymers were prepared by chemically binding poly(l-lactide) (PLLA) chains along chitosan (CS) via the “grafting to” approach to obtain hybrid biomaterials that present enhanced mechanical stability, due to the presence of PLLA, and high bioactivity, conferred by CS. Two graft copolymers were prepared, CS-g-PLLA(80/20) and CS-g-PLLA(50/50), containing 82 wt % and 55 wt % CS, respectively. Degradation studies of compressed discs of the copolymers showed that the degradation rate increased with the CS content of the copolymer. Nanomechanical studies in the dry state indicated that the copolymer with the higher CS content had larger Young modulus, reduced modulus and hardness values, whereas the moduli and hardness decreased rapidly following immersion of the copolymer discs in alpha-MEM cell culture medium for 24 h. Finally, the bioactivity of the hybrid copolymers was evaluated in the adhesion and growth of MC3T3-E1 pre-osteoblastic cells. In vitro studies showed that MC3T3-E1 cells exhibited strong adhesion on both CS-g-PLLA graft copolymer films from the first day in cell culture, whereas the copolymer with the higher PLLA content, CS-g-PLLA(50/50), supported higher cell growth.

scholarly journals Recent Advances on Stimuli-Responsive Hydrogels Based on Tissue-Derived ECMs and Their Components: Towards Improving Functionality for Tissue Engineering and Controlled Drug Delivery

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3263
Author(s):  
Julian A. Serna ◽  
Laura Rueda-Gensini ◽  
Daniela N. Céspedes-Valenzuela ◽  
Javier Cifuentes ◽  
Juan C. Cruz ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Disease Modeling ◽  
Mechanical Stability ◽  
Biological Properties ◽  
Stimuli Responsive ◽  
Precise Control ◽  
External Stimuli

Due to their highly hydrophilic nature and compositional versatility, hydrogels have assumed a protagonic role in the development of physiologically relevant tissues for several biomedical applications, such as in vivo tissue replacement or regeneration and in vitro disease modeling. By forming interconnected polymeric networks, hydrogels can be loaded with therapeutic agents, small molecules, or cells to deliver them locally to specific tissues or act as scaffolds for hosting cellular development. Hydrogels derived from decellularized extracellular matrices (dECMs), in particular, have gained significant attention in the fields of tissue engineering and regenerative medicine due to their inherently high biomimetic capabilities and endowment of a wide variety of bioactive cues capable of directing cellular behavior. However, these hydrogels often exhibit poor mechanical stability, and their biological properties alone are not enough to direct the development of tissue constructs with functional phenotypes. This review highlights the different ways in which external stimuli (e.g., light, thermal, mechanical, electric, magnetic, and acoustic) have been employed to improve the performance of dECM-based hydrogels for tissue engineering and regenerative medicine applications. Specifically, we outline how these stimuli have been implemented to improve their mechanical stability, tune their microarchitectural characteristics, facilitate tissue morphogenesis and enable precise control of drug release profiles. The strategic coupling of the bioactive features of dECM-based hydrogels with these stimulation schemes grants considerable advances in the development of functional hydrogels for a wide variety of applications within these fields.

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.

Design and Synthesis of Lipophilic Phosphoramidate d4T-MP Prodrugs Expressing High Potency Against HIV in Cell Culture:  Structural Determinants for in Vitro Activity and QSAR

1999 ◽  
Vol 42 (20) ◽  
pp. 4122-4128 ◽  
Author(s):  
Adam Q. Siddiqui ◽  
Christopher McGuigan ◽  
Carlo Ballatore ◽  
Fabio Zuccotto ◽  
Ian H. Gilbert ◽  
...  
Keyword(s):  
Cell Culture ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
High Potency ◽  
Structural Determinants ◽  
Design And Synthesis

scholarly journals Suture Fiber Reinforcement of a 3D Printed Gelatin Scaffold for Its Potential Application in Soft Tissue Engineering

2021 ◽  
Vol 22 (21) ◽  
pp. 11600
Author(s):  
Dong Jin Choi ◽  
Kyoung Choi ◽  
Sang Jun Park ◽  
Young-Jin Kim ◽  
Seok Chung ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mechanical Strength ◽  
Physical Properties ◽  
Dimensional Stability ◽  
3D Structure ◽  
Biological Properties ◽  
Dermal Fibroblasts ◽  
3D Scaffolds ◽  
3D Printed

Gelatin has excellent biological properties, but its poor physical properties are a major obstacle to its use as a biomaterial ink. These disadvantages not only worsen the printability of gelatin biomaterial ink, but also reduce the dimensional stability of its 3D scaffolds and limit its application in the tissue engineering field. Herein, biodegradable suture fibers were added into a gelatin biomaterial ink to improve the printability, mechanical strength, and dimensional stability of the 3D printed scaffolds. The suture fiber reinforced gelatin 3D scaffolds were fabricated using the thermo-responsive properties of gelatin under optimized 3D printing conditions (−10 °C cryogenic plate, 40–80 kPa pneumatic pressure, and 9 mm/s printing speed), and were crosslinked using EDC/NHS to maintain their 3D structures. Scanning electron microscopy images revealed that the morphologies of the 3D printed scaffolds maintained their 3D structure after crosslinking. The addition of 0.5% (w/v) of suture fibers increased the printing accuracy of the 3D printed scaffolds to 97%. The suture fibers also increased the mechanical strength of the 3D printed scaffolds by up to 6-fold, and the degradation rate could be controlled by the suture fiber content. In in vitro cell studies, DNA assay results showed that human dermal fibroblasts’ proliferation rate of a 3D printed scaffold containing 0.5% suture fiber was 10% higher than that of a 3D printed scaffold without suture fibers after 14 days of culture. Interestingly, the supplement of suture fibers into gelatin biomaterial ink was able to minimize the cell-mediated contraction of the cell cultured 3D scaffolds over the cell culture period. These results show that advanced biomaterial inks can be developed by supplementing biodegradable fibers to improve the poor physical properties of natural polymer-based biomaterial inks.

FABRICATION AND CHARACTERIZATION OF CALCIUM SILICATE SCAFFOLDS FOR TISSUE ENGINEERING

2014 ◽  
Vol 14 (04) ◽  
pp. 1450049 ◽  
Author(s):  
CIJUN SHUAI ◽  
ZHONGZHENG MAO ◽  
ZIKAI HAN ◽  
SHUPING PENG ◽  
ZHENG LI
Keyword(s):  
Tissue Engineering ◽  
Calcium Silicate ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Biological Properties ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Conventional Technology

Calcium silicate ( CaSiO 3) is a promising material due to its favorable biological properties. However, it was difficult to fabricate ceramic scaffolds with interconnected porous structure via conventional technology. In present study, CaSiO 3 scaffolds with totally interconnected pores were fabricated via selective laser sintering (SLS). The microstructure, mechanical and biological properties were examined. The results revealed that the powder gradually fused together with the reduction of voids and the elimination of particle boundary as the laser power increased in the range of 3–15 W with scanning electron microscope. Meanwhile the low-temperature phase (β- CaSiO 3) transformed into high-temperature phase (α- CaSiO 3) gradually, which decreased the mechanical properties of the obtained scaffolds. Besides, the compressive strength increased from 12.9 ± 2.34 MPa to 18.19 ± 1.24 MPa (the laser power is 12 w) and then decreased gradually with increasing laser power. In vitro biological properties of CaSiO 3 scaffolds sintered under optimal conditions indicated that the distribution of apatite mineralization became uniform as the amount of them increased after being immersed in simulated body fluids. In the meantime, the thin cytoplasmic extensions of MG-63 cells increased until formed a dense cell layer after 1–5 days of cell culture. The results suggested that the CaSiO 3 scaffold fabricated via SLS has potential application for bone tissue engineering.

scholarly journals Graphene Oxide Oxygen Content Affects Physical and Biological Properties of Scaffolds Based on Chitosan/Graphene Oxide Conjugates

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1142 ◽  
Author(s):  
Iolanda Francolini ◽  
Elena Perugini ◽  
Ilaria Silvestro ◽  
Mariangela Lopreiato ◽  
Anna Scotto d’Abusco ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Mechanical Strength ◽  
Oxygen Content ◽  
Mechanical Stability ◽  
Biological Properties ◽  
Dermal Fibroblasts ◽  
Porous Scaffolds ◽  
Low Oxygen ◽  
Interdisciplinary Field

Tissue engineering is a highly interdisciplinary field of medicine aiming at regenerating damaged tissues by combining cells with porous scaffolds materials. Scaffolds are templates for tissue regeneration and should ensure suitable cell adhesion and mechanical stability throughout the application period. Chitosan (CS) is a biocompatible polymer highly investigated for scaffold preparation but suffers from poor mechanical strength. In this study, graphene oxide (GO) was conjugated to chitosan at two weight ratios 0.3% and 1%, and the resulting conjugates were used to prepare composite scaffolds with improved mechanical strength. To study the effect of GO oxidation degree on scaffold mechanical and biological properties, GO samples at two different oxygen contents were employed. The obtained GO/CS scaffolds were highly porous and showed good swelling in water, though to a lesser extent than pure CS scaffold. In contrast, GO increased scaffold thermal stability and mechanical strength with respect to pure CS, especially when the GO at low oxygen content was used. The scaffold in vitro cytocompatibility using human primary dermal fibroblasts was also affected by the type of used GO. Specifically, the GO with less content of oxygen provided the scaffold with the best biocompatibility.

Modification of Thai Silk Fibroin Scaffolds by Gelatin Conjugation for Tissue Engineering

2008 ◽  
Vol 55-57 ◽  
pp. 685-688 ◽  
Author(s):  
J. Chamchongkaset ◽  
Sorada Kanokpanont ◽  
David L. Kaplan ◽  
Siriporn Damrongsakkul
Keyword(s):  
Tissue Engineering ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Textile Industry ◽  
Three Dimensional ◽  
Biological Properties ◽  
Salt Leaching ◽  
Biological Compatibility ◽  
Salt Crystals

Silk has been used commercially as biomedical sutures for decades. Recently silk fibroin, especially from Bombyx mori silkworm, has been explored for many tissue engineering applications such as bone and cartilage due to its impressive biological compatibility and mechanical properties. In Thailand, Thai native silkworms have been long cultivated. Distinct characteristics of cocoon Thai silk are its yellow color and coarse filament. There is more sericin in Thai silk than in other Bombyx mori silks. These characteristics provide Thai silk a unique texture for textile industry. It is therefore the aim of this study to develop three-dimensional silk fibroin-based scaffolds from Thai yellow cocoon “Nangnoi-Srisaket” of Bombyx mori silkworms using salt-leaching method. To enhance the biological properties, type A gelatin, the denature form of collagen having good biocompactibility, was used to conjugate with silk fibroin scaffolds. The pore size of salt-leached silk fibroin scaffold structure represented the size of salt crystals used (600-710µm). After gelatin conjugation, gelatin was partly formed fibers inside the pores of silk fibroin scaffolds resulting in fiber-like structure with highly interconnection. Gelatin conjugation enhanced the compressive modulus of silk fibroin scaffolds by 93%. The results on in vitro culture using mouse osteoblast-like cells (MC3T3-E1) showed that gelatin conjugation could promote the cell proliferation in silk fibroin scaffolds. Moreover, the observed morphology of cells proliferated inside the scaffold after 14 days of culture showed the larger spreading area of cells on conjugated gelatin/silk fibroin scaffolds, compared to round-shaped cells on silk fibroin scaffolds. The results implied that Thai silk fibroin looked promising to be applied in tissue engineering and gelatin conjugation on Thai silk fibroin scaffolds could enhance the biological properties of scaffolds.

scholarly journals Synthesis and Properties of Flexible Polyurethane Using Ferric Catalyst for Hypopharyngeal Tissue Engineering

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhisen Shen ◽  
Jian Wang ◽  
Dakai Lu ◽  
Qun Li ◽  
Chongchang Zhou ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Matrix Material ◽  
Biological Properties ◽  
Hexamethylene Diisocyanate ◽  
Engineering Research ◽  
Biodegradable Polyurethane ◽  
Flexible Polyurethane ◽  
Hydrophilic Polyurethane

Biodegradable polyurethane is an ideal candidate material to fabricate tissue engineered hypopharynx from its good mechanical properties and biodegradability. We thus synthesized a hydrophilic polyurethane via reactions among polyethylene glycol (PEG), e-caprolactone (e-CL) and hexamethylene diisocyanate (HDI), and thrihydroxymethyl propane (TMP). The product possessed a fast degradability due to its good wettability and good mechanical parameters with the elongations at break (137 ± 10%) and tensile strength (4.73 ± 0.46 MPa), which will make it a good matrix material for soft tissue like hypopharynx. Its biological properties were evaluated viain vitroandin vivotests. The results showed that this hydrophilic polyurethane material can support hypopharyngeal fibroblast growth and owned good degradability and low inflammatory reaction in subcutaneous implantation. It will be proposed as the scaffold for hypopharyngeal tissue engineering research in our future study.

scholarly journals Cuttlefish Bone-Derived Biphasic Calcium Phosphate Scaffolds Coated with Sol-Gel Derived Bioactive Glass

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2711
Author(s):  
Ana S. Neto ◽  
Daniela Brazete ◽  
José M.F. Ferreira
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Calcium Phosphates ◽  
Sol Gel ◽  
Biological Properties ◽  
X Ray Diffraction ◽  
Bioactive Glasses ◽  
Hydrothermal Transformation

The combination of calcium phosphates with bioactive glasses (BG) has received an increased interest in the field of bone tissue engineering. In the present work, biphasic calcium phosphates (BCP) obtained by hydrothermal transformation of cuttlefish bone (CB) were coated with a Sr-, Mg- and Zn-doped sol-gel derived BG. The scaffolds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. The initial CB structure was maintained after hydrothermal transformation (HT) and the scaffold functionalization did not jeopardize the internal structure. The results of the in-vitro bioactivity after immersing the BG coated scaffolds in simulated body fluid (SBF) for 15 days showed the formation of apatite on the surface of the scaffolds. Overall, the functionalized CB derived BCP scaffolds revealed promising properties, but further assessment of the in-vitro biological properties is needed before being considered for their use in bone tissue engineering applications.

In Vitro Cytotoxicity Study of the Nano-Hydroxyapatite/Bacterial Cellulose Nanocomposites

2009 ◽  
Vol 610-613 ◽  
pp. 1011-1016 ◽  
Author(s):  
Yan Mei Chen ◽  
Ting Fei Xi ◽  
Yu Dong Zheng ◽  
Yi Zao Wan
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bacterial Cellulose ◽  
Bone Tissue ◽  
Biological Response ◽  
Biological Properties ◽  
In Vitro Cytotoxicity ◽  
National Standard ◽  
Target Cells

The nanocomposite of nano-hydroxyapatite/bacterial cellulose (nHA/BC) obtained by depositing in simulated body fluid (SBF), incorporating their excellent mechanical and biological properties, is expected to have potential applications in bone tissue engineering. However, the biological response evaluation of biomaterials is required to provide useful information to improve their design and application. In this article, the in vitro cytotoxicity of composites nHA/BC as well as its degradation residues was studied. Scanning electron microscopy (SEM) was used to observe the morphology of original materials and their degradation residues. The degree of degradation was evalued by measuring the concentration of reducing sugar (glucose) by ultraviolet spectrophotometer. Bone-forming osteoblasts (OB) and infinite culture cell line L929 fibroblasts were used to measure the cytotocixity of materials with MTT assay. Both kinds of cells in infusion proliferate greatly in a normal form and their relative growth rate (RGR) exceeds by 75%, which shows the cytotoxicity of materials is graded as 0~1, according to the national standard. Nevertheless, bone-forming OB cells, as a kind of target cells, are more susceptive on the cytotoxicity than infinite culture fibroblast cells L929. The results suggest the nanocomposite of nHA/BC without cytotoxicity is greatly promising as a kind of scaffold materials for bone tissue engineering and tissue functional cells are more suited to evaluate the cytotoxicity of biomedical materials.

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