Three-Dimensional (3D) Printed Microneedles for Microencapsulated Cell Extrusion

Farias, Chantell; Lyman, Roman; Hemingway, Cecilia; Chau, Huong; Mahacek, Anne; Bouzos, Evangelia; Mobed-Miremadi, Maryam

doi:10.3390/bioengineering5030059

Cited by 66 publications

(46 citation statements)

References 141 publications

(176 reference statements)

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“…Some reports use a syringe system and different concentrations of the sodium alginate solution for microcapsule crosslinking. The diameter of the capsules produced in these studies can range from 10 to 1000 µm [ 42 , 43 , 44 , 45 ]. However, a complete device is described herein, so that groups wishing to work with cellular microencapsulation can produce their own low-cost equipment, with reproducible results.…”

Section: Discussionmentioning

confidence: 99%

“…Chantel Farias and collaborators used a microencapsulation system with parameters similar to ours to microencapsulate HepG2 cell and human glioblastoma cell (U-87) in 2018. The authors observed significant loss of viability post-24 h incubation of the microencapsulated HepG2 cells, probably due to the spheroid formation detected after a day, limiting diffusion transport of oxygen and nutrients due to a stagnant microenvironment [ 43 ]. In our system, we have shown that cells remain viable 24 h after encapsulation, and further studies are warranted to define the viability of cells freed from the microcapsules, by approaching their ability to proliferate and differentiate.…”

Section: Discussionmentioning

confidence: 99%

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A Low-Cost Open Source Device for Cell Microencapsulation

et al. 2020

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Microencapsulation is a widely studied cell therapy and tissue bioengineering technique, since it is capable of creating an immune-privileged site, protecting encapsulated cells from the host immune system. Several polymers have been tested, but sodium alginate is in widespread use for cell encapsulation applications, due to its low toxicity and easy manipulation. Different cell encapsulation methods have been described in the literature using pressure differences or electrostatic changes with high cost commercial devices (about 30,000 US dollars). Herein, a low-cost device (about 100 US dollars) that can be created by commercial syringes or 3D printer devices has been developed. The capsules, whose diameter is around 500 µm and can decrease or increase according to the pressure applied to the system, is able to maintain cells viable and functional. The hydrogel porosity of the capsule indicates that the immune system is not capable of destroying host cells, demonstrating that new studies can be developed for cell therapy at low cost with microencapsulation production. This device may aid pre-clinical and clinical projects in low- and middle-income countries and is lined up with open source equipment devices.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

A Low-Cost Open Source Device for Cell Microencapsulation

et al. 2020

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“…The precision of FDM is influenced by various factors, such as temperature and large scale of release nozzle, which is hard to satisfy the printing precision of microneedles [17]. Similar limitations exist in SLA and SLS, while the minimum feature size of SLS and SLA is larger than 100 microns [18]. Moreover, SLS requires high power supply and printing temperature, which would raise the cost of fabrication.…”

Section: Of 11mentioning

confidence: 99%

3D Printed Multi-Functional Hydrogel Microneedles Based on High-Precision Digital Light Processing

Yao

Zhao

et al. 2019

Micromachines

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Traditional injection and extraction devices often appear painful and cumbersome for patients. In recent years, polymer microneedles (MNs) have become a novel tool in the field of clinical medicine and health. However, the cost of building MNs into any shapes still remains a challenge. In this paper, we proposed hydrogel microneedles fabricated by high-precision digital light processing (H-P DLP) 3D printing system. Benefits from the sharp protuberance and micro-porous of the hydrogel microneedle, the microneedle performed multifunctional tasks such as drug delivery and detection with minimally invasion. Critical parameters for the fabrication process were analyzed, and the mechanical properties of MNs were measured to find a balance between precision and stiffness. Results shows that the stiffness and precision were significantly influenced by exposure time of each layer, and optimized printing parameters provided a balance between precision and stiffness. Bio-compatible MNs based on our H-P DLP system was able to execute drug injection and drug detection in our experiments. This work provided a low-cost and fast method to build MNs with 3D building, qualified the mechanical performance, drug injection, drug detection ability of MNs, and may be helpful for the potential clinical application.

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“…However, these methods are costly, not readily available and therefore not convenient for in-house microneedle manufacture by most researchers interested in microneedle applications. Various low-cost vat photopolymerization-based AM methods have also been explored for MNA fabrication, including projection-based direct light processing (DLP) 41–44 and scanning-based stereolithography (SLA) 45,46 . In DLP, a digital mirror projects each cross-sectional layer which cures the photopolymer and this process is repeated as the part is built in a layer-by-layer approach.…”

Section: Introductionmentioning

confidence: 99%

Simple and customizable method for fabrication of high-aspect ratio microneedle molds using low-cost 3D printing

et al. 2019

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We present a simple and customizable microneedle mold fabrication technique using a low-cost desktop SLA 3D printer. As opposed to conventional microneedle fabrication methods, this technique neither requires complex and expensive manufacturing facilities nor expertise in microfabrication. While most low-cost 3D-printed microneedles to date display low aspect ratios and poor tip sharpness, we show that by introducing a two-step “Print & Fill” mold fabrication method, it is possible to obtain high-aspect ratio sharp needles that are capable of penetrating tissue. Studying first the effect of varying design input parameters and print settings, it is shown that printed needles are always shorter than specified. With decreasing input height, needles also begin displaying an increasingly greater than specified needle base diameter. Both factors contribute to low aspect ratio needles when attempting to print sub-millimeter height needles. By setting input height tall enough, it is possible to print needles with high-aspect ratios and tip radii of 20–40 µm. This tip sharpness is smaller than the specified printer resolution. Consequently, high-aspect ratio sharp needle arrays are printed in basins which are backfilled and cured in a second step, leaving sub-millimeter microneedles exposed resulting microneedle arrays which can be used as male masters. Silicone female master molds are then formed from the fabricated microneedle arrays. Using the molds, both carboxymethyl cellulose loaded with rhodamine B as well as polylactic acid microneedle arrays are produced and their quality examined. A skin insertion study is performed to demonstrate the functional capabilities of arrays made from the fabricated molds. This method can be easily adopted by the microneedle research community for in-house master mold fabrication and parametric optimization of microneedle arrays.

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Three-Dimensional (3D) Printed Microneedles for Microencapsulated Cell Extrusion

Cited by 66 publications

References 141 publications

A Low-Cost Open Source Device for Cell Microencapsulation

A Low-Cost Open Source Device for Cell Microencapsulation

3D Printed Multi-Functional Hydrogel Microneedles Based on High-Precision Digital Light Processing

Simple and customizable method for fabrication of high-aspect ratio microneedle molds using low-cost 3D printing

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