3D Bioprinting for Wound Healing and Skinlike Sensors

Category: Blog,From Academia
blank blank Jan 23, 2021

From Academia” features recent, relevant, close to commercialization academic publications. Subjects include but not limited to healthcare 3D printing, 3D bioprinting, and related emerging technologies. In this issue, we feature three publications focusing on 3D bioprinted skin sensors and a great review article on bioinks used for 3D bioprinting for wound healing. The first article focus on the design of a UV exposure sensor using color-changing hydrogel ink and bioprinting. In the second article, researchers demonstrated potential applications of skinlike sensors using a multifunctional nanocomposite hydrogel with LRH (Layered Rare-earth Hydroxide.) The final article is a review on bioinks used for 3D bioprinting for wound healing.

Email: Rance Tino (tino.rance@gmail.com) if you want to share relevant academic publications with us.

3D Printed Hydrogel-Based Sensors for Quantifying UV Exposure

Authored by Abraham Samuel Finny, Cindy Jiang, and Silvana Andreescu. ACS Applied Materials & Interfaces. 1 September 2020

Images of the 3D models (A) and testing of the printability of the inks (B). Copyright ACS Applied Materials & Interfaces
Images of the 3D models (A) and testing of the printability of the inks (B). Copyright ACS Applied Materials & Interfaces

Abstract: 

Exposure to excessive ultraviolet (UV) radiation can have detrimental effects on human health. Inexpensive easy-to-use sensors for monitoring UV radiation can allow broad-scale assessment of UV exposure, but their implementation requires technology that enables rapid and affordable manufacturing of these sensors on a large scale. Herein, we report a novel three-dimensional (3D) printing procedure and printable ink composition that produce robust, flexible, and wearable UV sensors.

To fabricate the sensors, a color-changing hydrogel ink was first developed from which standalone constructs were 3D printed. The ink contains alginate, gelatin, photoactive titanium dioxide nanoparticles, and dyes (methyl orange, methylene blue, and malachite green) in which the nanoparticles are used to initiate photocatalytic degradation of dyes, leading to discoloration of the dye.

The sensors resemble a color-changing tattoo that loses color upon exposure to UV. The viscosity and ink composition were optimized to achieve printability and tune the mechanical properties (e.g., modulus, hardness) of the sensors.

The optimized procedure enabled the one-step fabrication of mechanically stable sensors that can effectively measure outdoor sun exposure by quantifying the decrease in color, visible to the naked eye. Apart from being used as wearable sensors, these sensors have the potential to be used along with UV-based workspace sterilizing devices to ensure that surfaces have been efficiently exposed to UV. The sensors are inexpensive, stable, extremely robust, biodegradable, and easy to use. The tunability, biocompatibility, and printability of the ink offer excellent potential for developing advanced 3D printing methods that, in addition to UV sensors, can be applied more broadly to fabricate other sensing technologies for a variety of other applications.

Color discoloration over time with sun exposure. Graphs are showing a decrease in color intensity of images taken with a cell phone and measured with ImageJ software and pictures of MB (A), MG (B), and MO (C) sensors. Copyright ACS Applied Materials & Interfaces
Color discoloration over time with sun exposure. Graphs are showing a decrease in color intensity of images taken with a cell phone and measured with ImageJ software and pictures of MB (A), MG (B), and MO (C) sensors. Copyright ACS Applied Materials & Interfaces

Skin-Inspired Multifunctional Luminescent Hydrogel Containing Layered Rare-Earth Hydroxide with 3D Printability for Human Motion Sensing

Authored Yuanyuan Ren and Jiachun Feng. ACS Applied Materials & Interfaces. 20 January 2020

3D printed SA/PAAS/LRH hydrogel: (a) Photo of the 3D printing process. (b,e) Top and side photos of the printed hydrogel wafer with a grid structure (6 layers). (c,f) Top and side photos of the printed rectangular flexible hydrogel (5 layers). (d,g) Top and side photos of the printed hollow cylinder (15 layers). Copyright. ACS Applied Materials & Interfaces
3D printed SA/PAAS/LRH hydrogel: (a) Photo of the 3D printing process. (b,e) Top and side photos of the printed hydrogel wafer with a grid structure (6 layers). (c,f) Top and side photos of the printed rectangular flexible hydrogel (5 layers). (d,g) Top and side photos of the printed hollow cylinder (15 layers). Copyright. ACS Applied Materials & Interfaces

Abstract: 

The development of multifunctional hydrogels is gaining a lot of attention owing to its application in electronic skins, wearable electronics, and soft robotics.

In this study, an effective and facile one-step preparation strategy is developed to fabricate a multifunctional nanocomposite hydrogel consisting of sodium alginate/sodium polyacrylate/layered rare-earth hydroxide (LRH), where LRH plays multiple roles as a co-cross-linker and ionic carrier and is also the origin of fluorescence. The obtained LRH-based composite hydrogel exhibits excellent three-dimensional printing performance at room temperature.

When exposed to different humidity conditions, the hydrogel exhibits humidity-dependent electromechanical properties. The multiple functions of the resultant hydrogel are easily realized by just relying on the addition of cationic LRH nanoplates. A skinlike motion sensor with transparency is fabricated based on the printed hydrogel and is used to monitor human motion.

Owing to the fluorescence characteristics of lanthanide ions (Eu3+ and Tb3+) from LRH, the hydrogel shows highly tunable multicolored photoluminescence by adjusting the LRH constituent. This study reveals that multifunctional hydrogels have the potential for applications in sensing.

(a) Fluorescent colors of various hydrogels under 254 nm UV lamps and the fluorescence emission spectra of (b) SA/PAAS/LEuH, (c) SA/PAAS/LTbH, (d) SA/PAAS/LEu0.5Tb0.5H, and (e) SA/PAAS/LEu0.3Tb0.7H. (f) Color location of the multicolored photoluminescence on the CIE coordinates of various hydrogels excited at 254 nm. Luminescence decay of (g) Luminescence decay of (g) Eu3+ (5D0) and (h) Tb3+ (5D4) in SA/PAAS/LRH hydrogels at λem of 616 and 544 nm, respectively. A, B, C, D in (a) and (f) corresponds to the hydrogels of SA/PAAS/LEuH, SA/PAAS/LEu0.5Tb0.5H, SA/PAAS/LEu0.3Tb0.7H and SA/PAAS/LTbH, respectively. Copyright. ACS Applied Materials & Interfaces
(a) Fluorescent colors of various hydrogels under 254 nm UV lamps and the fluorescence emission spectra of (b) SA/PAAS/LEuH, (c) SA/PAAS/LTbH, (d) SA/PAAS/LEu0.5Tb0.5H, and (e) SA/PAAS/LEu0.3Tb0.7H. (f) Color location of the multicolored photoluminescence on the CIE coordinates of various hydrogels excited at 254 nm. Luminescence decay of (g) Luminescence decay of (g) Eu3+ (5D0) and (h) Tb3+ (5D4) in SA/PAAS/LRH hydrogels at λem of 616 and 544 nm, respectively. A, B, C, D in (a) and (f) corresponds to the hydrogels of SA/PAAS/LEuH, SA/PAAS/LEu0.5Tb0.5H, SA/PAAS/LEu0.3Tb0.7H and SA/PAAS/LTbH, respectively. Copyright. ACS Applied Materials & Interfaces

Natural 3D-Printed Bioinks for Skin Regeneration and Wound Healing: A Systematic Review

Authored by Ali Smandri, Abid Nordin, Ng Min Hwei, Kok-Yong Chin, Izhar Abd Aziz and Mh Busra Fauzi, MDPI Polymers. 18 July 2020 

Example of in situ skin bioprinting process, where, (a) Markers are placed around the wound area as reference points; (b) Wound area scanned with a hand-held ZScanner™ (Z700 scanner); (c) Geometric information obtained via scanning is then inputted in the form of an STL file to orient the scanned images to the standard coordinate system; (d) The scanned data with its coordinate system is used to generate the fill volume, and the path points for nozzle head to travel to print the fill volume; (e,f). Output code is then provided to the custom bioprinter control interface for generation of nozzle path needed to print fill volume. Figure and caption reused from Albanna et al. Copyright MDPI Polymers
Example of in situ skin bioprinting process, where, (a) Markers are placed around the wound area as reference points; (b) Wound area scanned with a hand-held ZScanner™ (Z700 scanner); (c) Geometric information obtained via scanning is then inputted in the form of an STL file to orient the scanned images to the standard coordinate system; (d) The scanned data with its coordinate system is used to generate the fill volume, and the path points for nozzle head to travel to print the fill volume; (e,f). Output code is then provided to the custom bioprinter control interface for the generation of nozzle path needed to print fill volume. Figure and caption reused from Albanna et al. Copyright MDPI Polymers

Abstract: 

Three-dimensional bioprinting has rapidly paralleled many biomedical applications and assisted in advancing the printing of complex human organs for a better therapeutic practice. The objective of this systematic review is to highlight evidence from the existing studies and evaluate the effectiveness of using natural-based bioinks in skin regeneration and wound healing.

A comprehensive search of all relevant original articles was performed based on prespecified eligibility criteria. The search was carried out using PubMed, Web of Science, Scopus, Medline Ovid, and ScienceDirect. Eighteen articles fulfilled the inclusion and exclusion criteria. The animal studies included a total of 151 animals with wound defects.

A variety of natural bioinks and skin living cells were implanted in vitro to give insight into the technique through different assessments and findings. Collagen and gelatin hydrogels were most commonly used as bioinks. The follow-up period ranged between one day and six weeks. The majority of animal studies reported that full wound closure was achieved after 2–4 weeks. The results of both in vitro cell culture and in vivo animal studies showed the positive impact of natural bioinks in promoting wound healing. Future research should be focused more on direct the bioprinting of skin wound treatments on animal models to open doors for human clinical trials. 

Automated Bioprinting

3D Printed Drug Delivering Medical Devices

3D Printing Ceramic Implants

3D Bioprinting Knee, Aneurysm Model, 3D Organization Using Microfluidics

3D Printing Pharmaceuticals and Drug Delivery Devices

3D Bioprinting The Heart & Cardiovascular System

3DHEALS Guides (Collective) – This is where we dive deep into subjects that you will find helpful for your projects and career.

3DEALS Expert Corner (Collective) – This is where we invite field experts to write their perspectives in a first-person narrative. To write for this column, please email: info@3dheals.com

3DHEALS From Academia (Collective) – This section features recent, relevant, close to commercialization academic publications in the space of healthcare 3D printing, 3D bioprinting, and related emerging technologies.

Other similar articles

Comments