Effect of Hydroxyapatite on Biodegradable Scaffolds Fabricated by SLS

2008 ◽  
Vol 396-398 ◽  
pp. 659-662 ◽  
Author(s):  
Szilvia Eosoly ◽  
Stefan Lohfeld ◽  
Dermot Brabazon

Selective laser sintering (SLS) has the potential to fabricate bioresorbable polymer / ceramic composite scaffolds with pre-designed external and internal architecture that can be used for bone tissue engineering applications. Scaffolds were fabricated using poly-ε-caprolactone as the base material. The effect of 15 and 30 wt% of hydroxyapatite (HA) addition was investigated in terms of compressive properties, accuracy, surface topology, and wettability. Fabricated dimensions of PCL microstructures showed great deviations from their nominal values. Average surface roughness was found to be Ra=25±4 µm. Increased HA content had no statistically significant effect on accuracy and surface roughness. However the addition of HA had a significant influence on compressive properties, hydrophobicity and wettability of the samples. Addition of 30 wt% HA improved initial compressive modulus of pure PCL scaffolds from 1.31±0.08 MPa to 1.58±0.18 MPa. Yield strength values increased from 0.14±0.07 MPa to 0.17±0.01 MPa by adding 15 wt% of HA, but decreased with further HA addition. Yield strain for all compositions was over ε=0.06. Increased HA content decreased hydrophobicity and increased wettability of scaffold surfaces. The study demonstrated the ability of SLS to fabricate tissue engineering scaffolds, and the positive effect of HA particle reinforcement in terms of compressive mechanical properties and surface characteristics

Author(s):  
Brock Partee ◽  
Scott J. Hollister ◽  
Suman Das

Tissue engineering combines principles of the life sciences and engineering to replace and repair damaged human tissue. Present practice generally requires the use of porous, bioresorbable scaffolds to serve as temporary 3D templates to guide cell attachment, differentiation, proliferation, and subsequent regenerate tissue formation. Such scaffolds are anticipated to play an important role in allowing physicians to simultaneously reconstruct and regenerate damaged human tissue such as bone, cartilage, ligament and tendon. Recent research strongly suggests the choice of scaffold material and its internal porous architecture significantly influence regenerate tissue structure and function. However, a lack of versatile biomaterials processing and fabrication methods capable of meeting the complex geometric and compositional requirements of tissue engineering scaffolds has slowed progress towards fully testing these promising findings. It is widely accepted that layered manufacturing methods such as selective laser sintering (SLS) have the potential to fulfill these needs. Our research aims to investigate the viability of using SLS to fabricate tissue engineering scaffolds composed of polycaprolactone (PCL), one of the most widely investigated biocompatible, bioresorbable materials for tissue engineering applications. In this work, we report our recent progress on porous scaffold design and fabrication, optimal SLS processing parameter development using systematic factorial design of experiments, and structural characterization via optical microscopy.


Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 948
Author(s):  
Kate Fox ◽  
Rahul Ratwatte ◽  
Marsilea A. Booth ◽  
Hoai My Tran ◽  
Phong A. Tran

Multifunctional scaffolds are becoming increasingly important in the field of tissue engineering. In this research, a composite material is developed using polycaprolactone (PCL) and detonation nanodiamond (ND) to take advantage of the unique properties of ND and the biodegradability of PCL polymer. Different ND loading concentrations are investigated, and the physicochemical properties of the composites are characterized. ND-PCL composite films show a higher surface roughness and hydrophilicity than PCL alone, with a slight decrease in tensile strength and a significant increase in degradation. Higher loading of ND also shows a higher osteoblast adhesion than the PCL alone sample. Finally, we show that the ND-PCL composites are successfully extruded to create a 3D scaffold demonstrating their potential as a composite material for tissue regeneration.


2007 ◽  
Vol 334-335 ◽  
pp. 1225-1228 ◽  
Author(s):  
Wen You Zhou ◽  
S.H. Lee ◽  
Min Wang ◽  
W.L. Cheung

This paper reports a study on the modification of a commercial selective laser sintering (SLS) machine for the fabrication of tissue engineering scaffolds from small quantities of poly(L-lactide) (PLLA) microspheres. A miniature build platform was designed, fabricated and installed in the build cylinder of a Sinterstation 2000 system. Porous scaffolds in the form of rectangular prism, 12.7×12.7×25.4 mm3, with interconnected square and round channels were designed using SolidWorks. For initial trials, DuraFormTM polyamide powder was used to build scaffolds with a designed porosity of ~70%. The actual porosity was found to be ~83%, which indicated that the sintered regions were not fully dense. PLLA microspheres in the size range of 5-30 μm were made using an oil-in-water emulsion solvent evaporation procedure and they were suitable for the SLS process. A porous scaffold was sintered from the PLLA microspheres with a laser power of 15W and a part bed temperature of 60oC. SEM examination showed that the PLLA microspheres were partially melted to form the scaffold. This study has demonstrated that it is feasible to build tissue engineering scaffolds from small amounts of biomaterials using a commercial SLS machine with suitable modifications.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Maryam Tamaddon ◽  
Sorousheh Samizadeh ◽  
Ling Wang ◽  
Gordon Blunn ◽  
Chaozong Liu

Large bone defects and nonunions are serious complications that are caused by extensive trauma or tumour. As traditional therapies fail to repair these critical-sized defects, tissue engineering scaffolds can be used to regenerate the damaged tissue. Highly porous titanium scaffolds, produced by selective laser sintering with mechanical properties in range of trabecular bone (compressive strength 35 MPa and modulus 73 MPa), can be used in these orthopaedic applications, if a stable mechanical fixation is provided. Hydroxyapatite coatings are generally considered essential and/or beneficial for bone formation; however, debonding of the coatings is one of the main concerns. We hypothesised that the titanium scaffolds have an intrinsic potential to induce bone formation without the need for a hydroxyapatite coating. In this paper, titanium scaffolds coated with hydroxyapatite using electrochemical method were fabricated and osteoinductivity of coated and noncoated scaffolds was compared in vitro. Alizarin Red quantification confirmed osteogenesis independent of coating. Bone formation and ingrowth into the titanium scaffolds were evaluated in sheep stifle joints. The examinations after 3 months revealed 70% bone ingrowth into the scaffold confirming its osteoinductive capacity. It is shown that the developed titanium scaffold has an intrinsic capacity for bone formation and is a suitable scaffold for bone tissue engineering.


2012 ◽  
Vol 584 ◽  
pp. 357-360
Author(s):  
C.D. Naiju ◽  
M. Adithan ◽  
P. Radhakrishnan ◽  
K. Annamalai

This work presents the results of a study carried out to determine the topology of lateral surface and its effect on the process parameters of components manufactured by selective laser sintering (SLS). Using Taguchi’s experimental technique, an orthogonal array of L4 had been developed. Surface roughness was measured along built direction and analysis of variance (ANOVA) technique was used to investigate the effect of process parameters and to identify main process parameter that influences surface roughness on SLS components. It has been found that slice thickness and scan spacing have more significant influence than the laser power. Microstructure of the sintered specimen along the build direction was studied using Scanning Electron Microscope (SEM). It was observed that variations in slice thickness affect surface topology of SLS components.


2005 ◽  
Vol 128 (2) ◽  
pp. 531-540 ◽  
Author(s):  
Brock Partee ◽  
Scott J. Hollister ◽  
Suman Das

Tissue engineering combines principles of the life sciences and engineering to replace and repair damaged human tissue. Present tissue engineering methods generally require the use of porous, bioresorbable scaffolds to serve as temporary three-dimensional templates to guide cell attachment, differentiation, proliferation, and subsequent regenerate tissue formation. Such scaffolds are anticipated to play an important role in allowing physicians to simultaneously reconstruct and regenerate damaged human tissues such as bone, cartilage, ligament, and tendon. Recent research strongly suggests that the choice of scaffold material and its internal porous architecture significantly influence regenerate tissue structure and function. However, a lack of versatile biomaterials processing and manufacturing methods capable of meeting the complex geometric and compositional requirements of tissue engineering scaffolds has slowed progress towards fully testing these promising findings. It is widely accepted that layered manufacturing methods such as selective laser sintering (SLS) have the potential to address these requirements. We have investigated SLS as a technique to fabricate tissue engineering scaffolds composed of polycaprolactone (PCL), one of the most widely investigated biocompatible, bioresorbable materials for tissue engineering applications. In this article, we report on our development of optimal SLS processing parameters for CAPA® 6501 PCL powder using systematic factorial design of experiments. Using the optimal parameters, we manufactured test scaffolds with designed porous channels and achieved dimensional accuracy to within 3%–8% of design specifications and densities approximately 94% relative to full density. Finally, using the optimal SLS process parameters, we demonstrated the successful fabrication of bone tissue engineering scaffolds based on actual minipig and human condyle scaffold designs.


2021 ◽  
Vol 22 (7) ◽  
pp. 3504
Author(s):  
Reza Zeinali ◽  
Luis J. del Valle ◽  
Joan Torras ◽  
Jordi Puiggalí

Porous biodegradable scaffolds provide a physical substrate for cells allowing them to attach, proliferate and guide the formation of new tissues. A variety of techniques have been developed to fabricate tissue engineering (TE) scaffolds, among them the most relevant is the thermally-induced phase separation (TIPS). This technique has been widely used in recent years to fabricate three-dimensional (3D) TE scaffolds. Low production cost, simple experimental procedure and easy processability together with the capability to produce highly porous scaffolds with controllable architecture justify the popularity of TIPS. This paper provides a general overview of the TIPS methodology applied for the preparation of 3D porous TE scaffolds. The recent advances in the fabrication of porous scaffolds through this technique, in terms of technology and material selection, have been reviewed. In addition, how properties can be effectively modified to serve as ideal substrates for specific target cells has been specifically addressed. Additionally, examples are offered with respect to changes of TIPS procedure parameters, the combination of TIPS with other techniques and innovations in polymer or filler selection.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Rongtao Liu ◽  
Shiyang Zhang ◽  
Chen Zhao ◽  
Dong Yang ◽  
Tingting Cui ◽  
...  

AbstractConductive and degradable nanofibrous scaffolds have great potential in promoting cell growth, proliferation, and differentiation under an external electric field. Although the issue of inferior electrical conductivity in body fluids still exists, polyaniline (PANI)-based degradable nanofibers can promote cell adhesion, growth, and proliferation. To investigate whether the effect is caused by the PANI morphology, we selected three inorganic acids as dopants in the process of PANI in situ oxidative polymerization: hydrochloric acid, sulfuric acid, and perchloric acid. The obtained polyaniline/polylactic acid (PANI/PLA) composite nanofibers were characterized via SEM, FTIR, and XPS analysis, and we confirmed that the PLA nanofibers were successfully coated by PANI without any change to the porous structure of the PLA nanofibers. The in vitro mechanical properties and degradability indicated that the oxidation of acid dopants should be considered and that it was likely to have a higher oxidation degradation effect on PLA nanofibers. The contact angle test demonstrated that PANI/PLA composite nanofibers with different surface morphologies have good wettability, implying that they meet the requirements of bone tissue engineering scaffolds. The surface roughness and cell viability demonstrated that different PANI morphologies on the surface can promote cell proliferation. The higher the surface roughness of the PANI, the better the biocompatibility. Consequently, the regulated surface morphology of PANI/PLA composite nanofibers via different acids doping has positive effect on biocompatibility in tissue engineering.


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