IN VITRO EXPERIMENTS ON LASER SINTERED POROUS PCL SCAFFOLDS WITH POLYMER HYDROGEL FOR BONE REPAIR

2011 ◽  
Vol 11 (05) ◽  
pp. 983-992 ◽  
Author(s):  
MING-YIH LEE ◽  
SI-WEN LIU ◽  
JYH-PING CHEN ◽  
HAN-TSUNG LIAO ◽  
WEN-WEI TSAI ◽  
...  

Bone defects caused by tumors, diseased infection, trauma or abnormal bone development create a lot of serious health problems. Tissue engineering aims to fabricate tissues or organs using patients' cells for repairing the damaged tissues or organs in clinic. The aim of this study was to design and fabricate polycaprolactone (PCL) scaffolds using the inhouse-built selective laser sintering (SLS) rapid prototyping (RP) machine and combining with polymer hydrogel for in vitro study for bone repair. In this study, three configurations of scaffolds structure (0/45/0/45°, 0/90/0/90°, and 0/45/90/135° patterns) were designed and produced. The compressive modulus, porosity and pore size of porous scaffolds were first determined. In addition, polymer hydrogel was combined with PCL scaffolds with three loading methods (i.e., immersion method, injection method and titration method) to enhance scaffolds surface hydrophilicity for cell proliferation. Mesenchymal stem cells from New Zealand White rabbits were loaded on PCL scaffolds and induced to osteoblasts in vitro. Bone formation was determined by MTS assays, von Kossa stains and ALP activities. The experimental results showed the compressive moduli of scaffolds with 0/45/0/45°, 0/90/0/90°, and 0/45/90/135° patterns was 2 MPa, 3.4 MPa, and 3.75 MPa, respectively. The porosity of scaffolds was 72%, 76%, and 83%, respectively. The ranges of pore size of scaffolds were 350–400 μm, 400–500 μm, and 350–400 μm, respectively. By comparing three kinds of polymer hydrogel loading methods, titration method had the best result. The in vitro experimental results revealed that OD values of MTS tests and ALP activities increased from day 7 to day 21 and von Kossa stain revealed dark brown mineralized tissue, indicating cells could proliferate and differentiate in polymer hydrogel and scaffolds.

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Chengyong Li ◽  
Tingting Yan ◽  
Zhenkai Lou ◽  
Zhimin Jiang ◽  
Zhi Shi ◽  
...  

Abstract Background Large bone defects have always been a great challenge for orthopedic surgeons. The use of a good bone substitute obtained by bone tissue engineering (BTE) may be an effective treatment method. Artificial hydroxyapatite, a commonly used bone defect filler, is the main inorganic component of bones. Because of its high brittleness, fragility, and lack of osteogenic active elements, its application is limited. Therefore, its fragility should be reduced, its osteogenic activity should be improved, and a more suitable scaffold should be constructed. Methods In this study, a microhydroxyapatite whisker (mHAw) was developed, which was doped with the essential trace active elements Mg2+ and Sr2+ through a low-temperature sintering technique. After being formulated into a slurry, a bionic porous scaffold was manufactured by extrusion molding and freeze drying, and then SiO2 was used to improve the mechanical properties of the scaffold. The hydrophilicity, pore size, surface morphology, surface roughness, mechanical properties, and release rate of the osteogenic elements of the prepared scaffold were detected and analyzed. In in vitro experiments, Sprague–Dawley (SD) rat bone marrow mesenchymal stem cells (rBMSCs) were cultured on the scaffold to evaluate cytotoxicity, cell proliferation, spreading, and osteogenic differentiation. Results Four types of scaffolds were obtained: mHAw-SiO2 (SHA), Mg-doped mHAw-SiO2 (SMHA), Sr-doped mHAw-SiO2 (SSHA), and Mg-Sr codoped mHAw-SiO2 (SMSHA). SHA was the most hydrophilic (WCA 5°), while SMHA was the least (WCA 8°); SMHA had the smallest pore size (247.40 ± 23.66 μm), while SSHA had the largest (286.20 ± 19.04 μm); SHA had the smallest Young's modulus (122.43 ± 28.79 MPa), while SSHA had the largest (188.44 ± 47.89 MPa); and SHA had the smallest compressive strength (1.72 ± 0.29 MPa), while SMHA had the largest (2.47 ± 0.25 MPa). The osteogenic active elements Si, Mg, and Sr were evenly distributed and could be sustainably released from the scaffolds. None of the scaffolds had cytotoxicity. SMSHA had the highest supporting cell proliferation and spreading rate, and its ability to promote osteogenic differentiation of rBMSCs was also the strongest. Conclusions These composite porous scaffolds not only have acceptable physical and chemical properties suitable for BTE but also have higher osteogenic bioactivity and can possibly serve as potential bone repair materials.


Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde


2021 ◽  
Vol 11 (12) ◽  
pp. 2313-2320
Author(s):  
Jian Zhao ◽  
Wei Li ◽  
Xin Dong ◽  
Jiying Chen

Based on bioactive glasses (BG) of 58S, sol–gel method is used to prepare strontium oxide substituted bioactive glasses (SrO-BG) with different strontium content. SrO-BG and nano hydroxyapatite (HAp) composite materials were synthesized using precipitation method. The phase composition and morphologies of the prepared materials were examined by x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The dissolution and bio-mineralization of SrO-BG and SrO-BG/HAp composites in SBF are investigated by immersion method. The effects of secretion components of macrophages regulated by strontium doped SrO-BG/HAp composites on the osteogenic differentiation (OD) of bone marrow mesenchymal stem cells (BMSCs) are analyzed. The results demonstrate that the SrO-BG can inhibit the dissolution of BG. Different proportions of SrO-BG/HAp composites show good ability to induce HAp in SBF. The bio-mineralization ability of SrO-BG/HAp composites increases with the increase of SrO-BG content. The results of dissolution behavior and bio-mineralization of SrO-BG/HAp composite show that the dissolution rate of each ion can be controlled by adjusting the content of SrO-BG in the composite, and then the degradation rate can effectively be controlled. The results of in vitro experiments show that SrO-BG/HAp composites with 2%, 5% and 8% strontium content are more effective in promoting M2 polarization of macrophages than SrO-BG/HAp composites with 0% strontium content. Among them, 5% strontium doped SrO-BG/HAp has the strongest effect on M2 polarization of macrophages, and the secretion of macrophages regulated by 5% strontium doped SrO-BG/HAp composite is more conducive to bone repair.


Author(s):  
Y. Wu ◽  
J. Y. H. Fuh ◽  
Y. S. Wong ◽  
J. Sun

Current clinical grafts used in tendon treatment are subject to several restrictions and there is a significant demand for alternative engineered tissue. The previously reported tendon scaffolds mainly based on electrospinning and textile technologies showed promising results for tendon regeneration. However, limitations, such as small pore size, nutrition transmission, cell attachment, exist universally in such scaffolds. In this work, a novel tissue engineered polycaprolactone (PCL) tendon scaffold based on electrohydrodynamic jet printing (E-Jetting) was developed for investigation. In preliminary in-vitro study, human tenocytes were seeded in scaffolds with pore size of ∼106 μm to investigate the cell attachment, morphology and alignment. This study suggested that E-jetted tendon scaffold highly mimicked hierarchical construction from fiber to fascicle level of the native tendon, and has potential to be an alternative tendon regeneration tool.


2019 ◽  
Vol 68 (4) ◽  
pp. 22-29
Author(s):  
S.M. Naga ◽  
H.F. El-Maghraby ◽  
E.M. Mahmoud ◽  
A. Killinger ◽  
R. Gadow

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2589 ◽  
Author(s):  
Fei Liu ◽  
Qichun Ran ◽  
Miao Zhao ◽  
Tao Zhang ◽  
David Z. Zhang ◽  
...  

Porous scaffolds with graded open porosity combining a morphology similar to that of bone with mechanical and biological properties are becoming an attractive candidate for bone grafts. In this work, scaffolds with a continuous cell-size gradient were studied from the aspects of pore properties, mechanical properties and bio-functional properties. Using a mathematical method named triply periodic minimal surfaces (TPMS), uniform and graded scaffolds with Gyroid and Diamond units were manufactured by selective laser melting (SLM) with Ti-6Al-4V, followed by micro-computer tomography (CT) reconstruction, mechanical testing and in vitro evaluation. It was found that gradient scaffolds were preferably replicated by SLM with continuous graded changes in surface area and pore size, but their pore size should be designed to be ≥ 450 μm to ensure good interconnectivity. Both the Gyroid and Diamond structures have superior strength compared to cancellous bones, and their elastic modulus is comparable to the bones. In comparison, Gyroid exhibits better performances than Diamond in terms of the elastic modulus, ultimate strength and ductility. In vitro cell culture experiments show that the gradients provide an ideal growth environment for osteoblast growth in which cells survive well and distribute uniformly due to biocompatibility of the Ti-6Al-4V material, interconnectivity and suitable pore size.


2019 ◽  
Vol 28 (5) ◽  
pp. 320-330
Author(s):  
Nazanin Marouf ◽  
Hanieh Nojehdehian ◽  
Farnaz Ghorbani

To investigate the potential of biomaterials for bone repair, Ginkgo biloba (GB)-loaded polylactic- co-glycolic acid microspheres were synthesized via solvent evaporation technique, and scanning electron microscopic (SEM) micrographs indicated a spherical and smooth surface in which the particles were distributed in the range of 1–7 µm. Chitosan–hydroxyapatite (HA) matrixes incorporated with polymeric spheres were fabricated using the freeze-drying method. SEM micrographs demonstrated an interconnected porous structure in which porosity and pore size reduced as a function of HA and microsphere addition. Fourier transform infrared spectrum illustrated the ability of sodium tripolyphosphate in cross-linking of composite scaffolds. Swelling ratio presented that higher amount of microspheres and the addition of HA reduce the ability of interaction with water molecules. The GB release behavior of hybrid scaffolds confirmed that the addition of HA significantly reduces release ratio because of a slight reduction in pore size and PBS absorption capacity, but higher amount of microspheres resulted in an increase in release level. According to the results, the synthesized hybrid scaffolds have the initial physicochemical features for further studies in terms of in vitro and in vivo assays.


Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1120
Author(s):  
Wafa Shamsan Al-Arjan ◽  
Muhammad Umar Aslam Khan ◽  
Samina Nazir ◽  
Saiful Izwan Abd Razak ◽  
Mohammed Rafiq Abdul Kadir

Fabrication of reinforced scaffolds to repair and regenerate defected bone is still a major challenge. Bone tissue engineering is an advanced medical strategy to restore or regenerate damaged bone. The excellent biocompatibility and osteogenesis behavior of porous scaffolds play a critical role in bone regeneration. In current studies, we synthesized polymeric nanocomposite material through free-radical polymerization to fabricate porous nanocomposite scaffolds by freeze drying. Functional group, surface morphology, porosity, pore size, and mechanical strength were examined through Fourier Transform Infrared Spectroscopy (FTIR), Single-Electron Microscopy (SEM), Brunauer-Emmet-Teller (BET), and Universal Testing Machine (UTM), respectively. These nanocomposites exhibit enhanced compressive strength (from 4.1 to 16.90 MPa), Young’s modulus (from 13.27 to 29.65 MPa) with well appropriate porosity and pore size (from 63.72 ± 1.9 to 45.75 ± 6.7 µm), and a foam-like morphology. The increasing amount of graphene oxide (GO) regulates the porosity and mechanical behavior of the nanocomposite scaffolds. The loading and sustained release of silver-sulfadiazine was observed to be 90.6% after 260 min. The in-vitro analysis was performed using mouse pre-osteoblast (MC3T3-E1) cell lines. The developed nanocomposite scaffolds exhibited excellent biocompatibility. Based on the results, we propose these novel nanocomposites can serve as potential future biomaterials to repair defected bone with the load-bearing application, and in bone tissue engineering.


2015 ◽  
Vol 21 (6) ◽  
pp. 716-724 ◽  
Author(s):  
Ramakrishna Vasireddi ◽  
Bikramjit Basu

Purpose – The purpose of this paper is to investigate the possibility to construct tissue-engineered bone repair scaffolds with pore size distributions using rapid prototyping techniques. Design/methodology/approach – The fabrication of porous scaffolds with complex porous architectures represents a major challenge in tissue engineering and the design aspects to mimic complex pore shape as well as spatial distribution of pore sizes of natural hard tissue remain unexplored. In this context, this work aims to evaluate the three-dimensional printing process to study its potential for scaffold fabrication as well as some innovative design of homogeneously porous or gradient porous scaffolds is described and such design has wider implication in the field of bone tissue engineering. Findings – The present work discusses biomedically relevant various design strategies with spatial/radial gradient in pore sizes as well as with different pore sizes and with different pore geometries. Originality/value – One of the important implications of the proposed novel design scheme would be the development of porous bioactive/biodegradable composites with gradient pore size, porosity, composition and with spatially distributed biochemical stimuli so that stem cells loaded into scaffolds would develop into complex tissues such as those at the bone–cartilage interface.


2021 ◽  
Author(s):  
Chengyong Li ◽  
Tingting Yan ◽  
Zhenkai Lou ◽  
Zhimin Jiang ◽  
Zhi Shi ◽  
...  

Abstract Background Orthopedics has made great progress with the development of medical treatment; however, large bone defects are still great challenges for orthopedic surgeons. A good bone substitute that can be obtained through bone tissue engineering may be an effective treatment method. Artificial hydroxyapatite is the main inorganic component of bones, but its applications are limited due to its fragility and lack of bone-active elements. Therefore, it is necessary to reduce its fragility and improve its biological activity. Methods In this study, we developed micro-hydroxyapatite whiskers (mHAws), which were doped with the essential trace active elements Mg2+ and Sr2+ through a low-temperature sintering technique, used silica complexes to improve the mechanical properties, and then manufactured the bionic porous scaffolds by extrusion molding and freeze-drying. Results Four types of scaffolds were obtained: mHAw-SiO2, Mg-doped mHAw-SiO2, Sr-doped mHAw-SiO2 and Mg-Sr-codoped mHAw-SiO2. These composite porous scaffolds have been suggested to have a sufficiently porous morphology with appropriate mechanical strength, are noncytotoxic, are able to support cell proliferation and spreading, and, more importantly, can promote the osteogenic differentiation of rBMSCs. Conclusion Therefore, these doped scaffolds not only have physical and chemical properties suitable for bone tissue engineering, but also have higher osteogenic bioactivity, and can be possibly serve as potential bone repair material.


Sign in / Sign up

Export Citation Format

Share Document