Development of a novel bioartificial cornea using 3D bioprinting based on electrospun micro-nanofibrous decellularized extracellular matrix.

Corneal damage contributes to blindness in millions of people. Simulating natural corneas with artificial corneas is challenging due to material and manufacturing limitations, including poor mechanical properties, complex manufacturing processes, and ocular histocompatibility. In this study, electrospun micro-nanofibrous decellularized extracellular matrix (dECM) is combined with digital light processing 3D bioprinting and validated as a bioartificial cornea for the first time. Electrospinning gives the material a controllable shape, and the electrospun micro-nanofibrous dECM, with preserved inherent biochemical components, can better mimic the natural ECM native microenvironment. An efficient platform can be developed for creating novel structural materials, when combined with intelligent manufacturing. Artificial biological corneas developed using this method showed five-fold improvements in mechanical properties (248.5 ± 35.67 kPa vs. 56.91 ± 3.68 kPa,p< 0.001), superior guidance for cell organization and adhesion, and better maintenance of the cellular phenotype of keratocytes. In animal studies,in vivotransplantation of this artificial cornea showed better regeneration, which accelerated corneal epithelialization and maintained corneal transparency. This method has potential for biomedical applications, and bioartificial corneas manufactured by this method have ideal properties as an alternative to lamellar keratoplasty, with promise for clinical transformation.

An Image-Based High-Throughput and High-Content Drug Screening Method Based on Microarray and Expansion Microscopy.

A high-efficiency drug screening method is urgently needed due to the expanding number of potential targets and the extremely long time required to assess them. To date, high throughput and high content have not been successfully combined in image-based drug screening, which is the main obstacle to improve the efficiency. Here, we establish a high-throughput and high-content drug screening method by preparing a superhydrophobic microwell array plate (SMAP) and combining it with protein-retention expansion microscopy (proExM). Primarily, we described a flexible method to prepare the SMAP based on photolithography. Cells were cultured in the SMAP and treated with different drugs using a microcolumn-microwell sandwiching technology. After drug treatment, proExM was applied to realize super-resolution imaging. As a demonstration, a 7 × 7 image array of microtubules was successfully collected within 3 h with 68 nm resolution using this method. Qualitative and quantitative analyses of microtubule and mitochondria morphological changes after drug treatment suggested that more details were revealed after applying proExM, demonstrating the successful combination of high throughput and high content.

3D bioprinting of corneal decellularized extracellular matrix: GelMA composite hydrogel for corneal stroma engineering.

Millions of individuals across the world suffer from corneal stromal diseases that impair vision. Fortunately, three-dimensional (3D) bioprinting technology which has revolutionized the field of regenerative tissue engineering makes it feasible to create personalized corneas. In this study, an artificial cornea with a high degree of precision, smoothness, and programmable curvature was prepared by using digital light processing (DLP) 3D bioprinting in one piece with no support structure, and the construct was then confirmed by optical coherence tomography (OCT). On the basis of this approach, we developed a novel corneal decellularized extracellular matrix/gelatin methacryloyl (CECM-GelMA) bioink that can produce complex microenvironments with highly tunable mechanical properties while retaining high optical transmittance. Furthermore, the composite hydrogel was loaded with human corneal fibroblasts (hCFs), and in vitro experiments showed that the hydrogel maintained high cell viability and expressed core proteins. In vivo tests revealed that the hydrogel might promote epithelial regeneration, keep the matrix aligned, and restore clarity. This demonstrates how crucial a role CECM plays in establishing a favorable environment that encourages the transformation of cell function. Therefore, artificial corneas that can be rapidly customized have a huge potential in the development of in vitro corneal matrix analogs.

A high-performance GelMA-GelMA homogeneous double-network hydrogel assisted by 3D printing.

Gelatin methacryloyl (GelMA) is a popular photocrosslinkable hydrogel that has been widely utilized in tissue engineering and regenerative medicine fields due to its excellent biocompatibility, biodegradability and cell response. However, the lack of mechanical properties limits its application. In the present study, a method for the preparation of a GelMA-GelMA (G-G) homogeneous double-network (DN) hydrogel to improve mechanical strength based on DLP 3D printing is proposed. The G-G DN hydrogel was fabricated and characterized in terms of microstructure, mechanical properties and rheological behavior. By modifying the degree of substitution (DS), the polymer concentration of double network crosslinking and the soak time, the novel G-G DN hydrogel could significantly improve the properties of strength, self-recovery and fatigue resistance. After all, the novel porous composite hydrogel (G-G DN hydrogel) could achieve more than twice that of the pure GelMA hydrogel, better fatigue resistance and printable ability. Therefore, it can be a potential choice of applications attracting great attention for its mechanical properties, great transmittance and biocompatibility.