Photopolymers with tunable mechanical properties processed by laser-based high-resolution stereolithography

Stampfl, Jürgen; Baudis, Stefan; Heller, Christian; Liska, Robert; Neumeister, A.; Kling, Rainer; Ostendorf, Andreas; Spitzbart, Manfred

doi:10.1088/0960-1317/18/12/125014

Cited by 210 publications

(169 citation statements)

References 15 publications

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“…Microstereolithography systems are already commercially available [9]. However, this method can be used for fabrication of two-dimensional (2D) objects, and formation of three-dimensional (3D) structures becomes long and complex [10].…”

Section: Introductionmentioning

confidence: 99%

3D artificial polymeric scaffolds for stem cell growth fabricated by femtosecond laser

Malinauskas

Danilevičius²,

Baltriukienė³

et al. 2010

Lithuanian J. Phys.

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Femtosecond Laser Induced Polymerization is an attractive direct writing technique for rapid three-dimensional (3D) micro and nanofabrication in diverse applications. Recently, it has been successfully applied for 3D scaffold fabrication required in biomedicine applications. However, there are still a lot of investigations to be done before it can be used for practical applications in tissue engineering or regenerative medicine. In this work, experimental results on production of artificial polymeric scaffolds for stem cell growth are presented. Parameters (average laser power, sample scanning speed, and developing conditions) for microfabrication in biocompatible photopolymers AKRE (AKRE37) and ORMOSIL (SZ2080) are experimentally determined. 3D custom form and size artificial scaffolds were successfully microfabricated. Adult stem cell growth on them was investigated in order to test their biocompatibility. The results of myogenic stem cell culture expansion were compared to the control growth of the same cells on the scaffolds manufactured out of commonly used biocompatible photopolymers ORMOCER (Ormocore b59) and Poly-Ethylen Glycol Di-Acrylate (PEG-DA-258). Preliminary results show FLIP technique to have potential in fabrication of artificial 3D polymeric scaffolds for cell proliferation experiments. These are the first steps in transferring FLIP fabrication method from laboratory tests to flexible manufacturing of individual scaffolds out of biocompatible and biodegradable polymers.

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Section: Introductionmentioning

confidence: 99%

3D artificial polymeric scaffolds for stem cell growth fabricated by femtosecond laser

Malinauskas

Danilevičius²,

Baltriukienė³

et al. 2010

Lithuanian J. Phys.

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“…S6). Elastic moduli for the horizontally aligned sample were 967 ± 30 and 746 ± 77 MPa on top of the platelet island and on the platelet-free regions, respectively (45). For the vertically aligned sample we obtained an elastic modulus of 6,687 ± 760 MPa on top of platelets, and 2,168 ± 329 MPa for the platelet-free regions (Fig.…”

Section: Resultsmentioning

confidence: 71%

Periodically microstructured composite films made by electric- and magnetic-directed colloidal assembly

Demirörs

Courty

Libanori

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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Living organisms often combine soft and hard anisotropic building blocks to fabricate composite materials with complex microstructures and outstanding mechanical properties. An optimum design and assembly of the anisotropic components reinforces the material in specific directions and sites to best accommodate multidirectional external loads. Here, we fabricate composite films with periodic modulation of the soft-hard microstructure by simultaneously using electric and magnetic fields. We exploit forefront directed-assembly approaches to realize highly demanded material microstructural designs and showcase a unique example of how one can bridge colloidal sciences and composite technology to fabricate next-generation advanced structural materials. In the proof-of-concept experiments, electric fields are used to dictate the position of the anisotropic particles through dielectrophoresis, whereas a rotating magnetic field is used to control the orientation of the particles. By using such unprecedented control over the colloidal assembly process, we managed to fabricate ordered composite microstructures with up to 2.3-fold enhancement in wear resistance and unusual site-specific hardness that can be locally modulated by a factor of up to 2.5.L ightweight composites offer an attractive alternative toward minimization of the energy demand of mobility systems from automobiles and airplanes to trains and ships. Continuous stiff fibers or discontinuous anisotropic particles have often been used as reinforcing phase to enhance the specific mechanical properties of such lightweight polymer-based composites. Although the fabrication costs of long-fiber reinforced composites remain prohibitive for the large-scale production of high-performance materials, the processing of polymer-based composites reinforced with discontinuous stiff elements can often be adapted to the automated manufacturing processes commonly used in the polymer industry, such as injection molding. However, these fabrication processes usually offer a limited control over the alignment and spatial distribution of the reinforcing particles, preventing a full optimization of the microstructural design in composite materials. Thus, the development of new strategies to assemble microstructured composites with tailored reinforcing architectures is crucial for the design and fabrication of even lighter and cheaper structural materials.Control over the spatial distribution and orientation of particles in composites can be achieved using colloidal assembly tools that guide/template the organization of the reinforcing particles while the material is still in a fluid state. Recently, we have shown that control of particle orientation using an external magnetic field can lead to a significant increase in the materials' resistance against deformation, wear, and crack initiation, widening their range of applications (1, 2). Independent of orientation control, tuning the spatial distribution of particles through magnetic fields, centrifugal forces, or film welding techniq...

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“…In vitro degradation and mechanical properties of PLA-PCL copolymer unit cell scaffolds generated by two-photon polymerization patterning of materials in a layer-by-layer approach by stereo-lithography [16,17]. Generation of complex structures with high resolution and without the necessity of photomasks are the major advantages of direct laser writing techniques compared to traditional lithography methods.…”

Section: Introductionmentioning

confidence: 99%

In vitro degradation and mechanical properties of PLA-PCL copolymer unit cell scaffolds generated by two-photon polymerization

et al. 2016

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The manufacture of 3D scaffolds with specific controlled porous architecture, defined microstructure and an adjustable degradation profile was achieved using two-photon polymerization (TPP) with a size of 2 × 4 × 2 mm3. Scaffolds made from poly(D,L-lactide-co-ɛ-caprolactone) copolymer with varying lactic acid (LA) and ɛ -caprolactone (CL) ratios (LC16:4, 18:2 and 9:1) were generated via ring-opening-polymerization and photoactivation. The reactivity was quantified using photo-DSC, yielding a double bond conversion ranging from 70% to 90%. The pore sizes for all LC scaffolds were see 300 μm and throat sizes varied from 152 to 177 μm. In vitro degradation was conducted at different temperatures; 37, 50 and 65 °C. Change in compressive properties immersed at 37 °C over time was also measured. Variations in thermal, degradation and mechanical properties of the LC scaffolds were related to the LA/CL ratio. Scaffold LC16:4 showed significantly lower glass transition temperature (Tg) (4.8 °C) in comparison with the LC 18:2 and 9:1 (see 32 °C). Rates of mass loss for the LC16:4 scaffolds at all temperatures were significantly lower than that for LC18:2 and 9:1. The degradation activation energies for scaffold materials ranged from 82.7 to 94.9 kJ mol−1. A prediction for degradation time was applied through a correlation between long-term degradation studies at 37 °C and short-term studies at elevated temperatures (50 and 65 °C) using the half-life of mass loss (Time (M1/2)) parameter. However, the initial compressive moduli for LC18:2 and 9:1 scaffolds were 7 to 14 times higher than LC16:4 (see 0.27) which was suggested to be due to its higher CL content (20%). All scaffolds showed a gradual loss in their compressive strength and modulus over time as a result of progressive mass loss over time. The manufacturing process utilized and the scaffolds produced have potential for use in tissue engineering and regenerative medicine applications.

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Photopolymers with tunable mechanical properties processed by laser-based high-resolution stereolithography

Cited by 210 publications

References 15 publications

3D artificial polymeric scaffolds for stem cell growth fabricated by femtosecond laser

3D artificial polymeric scaffolds for stem cell growth fabricated by femtosecond laser

Periodically microstructured composite films made by electric- and magnetic-directed colloidal assembly

In vitro degradation and mechanical properties of PLA-PCL copolymer unit cell scaffolds generated by two-photon polymerization

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