Soft lithography based on photolithography and two-photon polymerization

Lin, Yang; Gao, Can; Gritsenko, Dmitry; Zhou, Renke; Xu, Jie

doi:10.1007/s10404-018-2118-5

Cited by 45 publications

(27 citation statements)

References 37 publications

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“…This type of polymer is commonly a simple mixture of the two compounds although it is possible to integrate the photoinitiator into the polymer itself. 8 Popular reactive moieties include epoxy, 9 thiol-ene, [10][11][12] and acrylate chemistries and are matched with a compatible photoinitiator chemistry. For example, SU-8 is a popular biocompatible polymer designed for the microelectronics industry but has found uses in biomedical research; this polymer uses epoxy ring-opening chemistries combined with a photoacid generator.…”

Section: A)mentioning

confidence: 99%

Toxicity and photosensitizing assessment of gelatin methacryloyl-based hydrogels photoinitiated with lithium phenyl-2,4,6-trimethylbenzoylphosphinate in human primary renal proximal tubule epithelial cells

et al. 2019

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Gelatin methacryloyl (GelMA) and lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator are commonly used in combination to produce a photosensitive polymer but there are concerns that must be addressed: the presence of unreacted monomer is well known to be cytotoxic, and lithium salts are known to cause acute kidney injury. In this study, acellular 10% GelMA hydrogels cross-linked with different LAP concentrations and cross-linking illumination times were evaluated for their cytotoxicity, photosensitizing potential, and elastic moduli. Alamar Blue and CyQuant Direct Cell viability assays were performed on human primary renal proximal tubule epithelial cells (hRPTECs) exposed to extracts of each formulation. UV exposure during cross-linking was not found to affect extract cytotoxicity in either assay. LAP concentration did not affect extract cytotoxicity as determined by the Alamar Blue assay but reduced hRPTEC viability in the CyQuant Direct cell assay. Photocatalytic activity of formulation extracts toward NADH oxidation was used as a screening method for photosensitizing potential; longer UV exposure durations yielded extracts with less photocatalytic activity. Finally, elastic moduli determined using nanoindentation was found to plateau to approximately 20-25 kPa after exposure to 342 mJ/cm 2 at 2.87 mW of UV-A exposure regardless of LAP concentration. LAP at concentrations commonly used in bioprinting (<0.5% w/w) was not found to be cytotoxic although the differences in cytotoxicity evaluation determined from the two viability assays imply cell membrane damage and should be investigated further. Complete cross-linking of all formulations decreased photocatalytic activity while maintaining predictable final elastic moduli.

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Section: A)mentioning

confidence: 99%

Toxicity and photosensitizing assessment of gelatin methacryloyl-based hydrogels photoinitiated with lithium phenyl-2,4,6-trimethylbenzoylphosphinate in human primary renal proximal tubule epithelial cells

et al. 2019

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“…This technology allows the fabrication of predesigned microstructures using various designs of molds, photomasks, and stamps [ 47 ]. Soft lithography also can be viewed as a complementary technique for photolithography as it can be used as a template to fabricate geometrically complex structures with biocompatible materials, allowing the creation of biological systems for cell/tissue growth [ 48 ]. The common material used in soft lithography is polydimethylsiloxane (PDMS), which can be classified into four core techniques: (1) Replica molding: simply duplicated the required structures by just pouring the PDMS on the predesigned pattern and cured ( Figure 3 A) [ 6 , 36 , 37 , 49 , 50 , 51 , 52 ].…”

Section: Lab-on-a-chip Microfabrication Methodsmentioning

confidence: 99%

Lab-on-a-Chip for Cardiovascular Physiology and Pathology

Beverung

Steward

2020

Micromachines

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Lab-on-a-chip technologies have allowed researchers to acquire a flexible, yet relatively inexpensive testbed to study one of the leading causes of death worldwide, cardiovascular disease. Cardiovascular diseases, such as peripheral artery disease, arteriosclerosis, and aortic stenosis, for example, have all been studied by lab-on-a-chip technologies. These technologies allow for the integration of mammalian cells into functional structures that mimic vital organs with geometries comparable to those found in vivo. For this review, we focus on microdevices that have been developed to study cardiovascular physiology and pathology. With these technologies, researchers can better understand the electrical–biomechanical properties unique to cardiomyocytes and better stimulate and understand the influence of blood flow on the human vasculature. Such studies have helped increase our understanding of many cardiovascular diseases in general; as such, we present here a review of the current state of the field and potential for the future.

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“…The application range of two-photon lithography ranges from the fabrication of photonic crystals 35 , cell scaffolds 36 to metamaterials 37 , biomimicry 38 , and additive manufactured microfluidics 39 . Two-photon lithography has been used 40 to incorporate optical components (e.g., a total internal reflecting mirror) with a microfluidic channel using soft lithography and to demonstrate the integration of a three-dimensional microfluidic mixer into photolithographically fabricated areas on a glass coverslip 41 . In this paper, we enhance the strategy of combining conventional UV lithography with two-photon direct laser writing to approach the nanofluidic regime on a silicon surface.…”

Section: Introductionmentioning

confidence: 99%

Scalable integration of nano-, and microfluidics with hybrid two-photon lithography

et al. 2019

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Nanofluidic devices have great potential for applications in areas ranging from renewable energy to human health. A crucial requirement for the successful operation of nanofluidic devices is the ability to interface them in a scalable manner with the outside world. Here, we demonstrate a hybrid two photon nanolithography approach interfaced with conventional mask whole-wafer UV-photolithography to generate master wafers for the fabrication of integrated micro and nanofluidic devices. Using this approach we demonstrate the fabrication of molds from SU-8 photoresist with nanofluidic features down to 230 nm lateral width and channel heights from micron to sub-100 nm. Scanning electron microscopy and atomic force microscopy were used to characterize the printing capabilities of the system and show the integration of nanofluidic channels into an existing microfluidic chip design. The functionality of the devices was demonstrated through super-resolution microscopy, allowing the observation of features below the diffraction limit of light produced using our approach. Single molecule localization of diffusing dye molecules verified the successful imprint of nanochannels and the spatial confinement of molecules to 200 nm across the nanochannel molded from the master wafer. This approach integrates readily with current microfluidic fabrication methods and allows the combination of microfluidic devices with locally two-photon-written nano-sized functionalities, enabling rapid nanofluidic device fabrication and enhancement of existing microfluidic device architectures with nanofluidic features.

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Soft lithography based on photolithography and two-photon polymerization

Cited by 45 publications

References 37 publications

Toxicity and photosensitizing assessment of gelatin methacryloyl-based hydrogels photoinitiated with lithium phenyl-2,4,6-trimethylbenzoylphosphinate in human primary renal proximal tubule epithelial cells

Toxicity and photosensitizing assessment of gelatin methacryloyl-based hydrogels photoinitiated with lithium phenyl-2,4,6-trimethylbenzoylphosphinate in human primary renal proximal tubule epithelial cells

Lab-on-a-Chip for Cardiovascular Physiology and Pathology

Scalable integration of nano-, and microfluidics with hybrid two-photon lithography

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