Tissue engineering of human ear pinna

Pharmaceutical applications and requirements of resins for printing by digital light processing (DLP)

The digital light processing (DLP) printer has proven to be effective in biomedical and pharmaceutical applications, as its printing method does not induce shear and a strong temperature on the resin. In addition, the DLP printer has good resolution and print quality, which makes it possible to print complex structures with a customized shape, being used for various purposes ranging from jewelry application to biomedical and pharmaceutical areas. The big disadvantage of DLP is the lack of a biocompatible and non-toxic resin on the market. To overcome this limitation, an ideal resin for biomedical and pharmaceutical use is needed. The resin must have appropriate properties, so that the desired format is printed when with a determined wavelength is applied. Thus, the aim of this work is to bring the basic characteristics of the resins used by this printing method and the minimum requirements to start printing by DLP for pharmaceutical and biomedical applications. The DLP method has proven to be effective in obtaining pharmaceutical devices such as drug delivery systems. Furthermore, this technology allows the printing of devices of ideal size, shape and dosage, providing the patient with personalized treatment.

Tissue engineering in otology: a review of achievements

Tissue engineering application in otology spans a distance from the pinna to auditory nerve covered with specialized tissues and functions such as sense of hearing and aesthetics. It holds the potential to address the barriers of lack of donor tissue, poor tissue match, and transplant rejection through provision of new and healthy tissues similar to the host and possesses the capacity to renew, to regenerate, and to repair in-vivo and was shown to be a bypasses for any need to immunosuppression. This review aims to investigate the application of tissue engineering in otology and to evaluate the achievements and challenges in external, middle and inner ear sections. Since gaining the recent knowledge and training on use of different scaffolds is essential for otology specialists and who look for the recovery of ear function and aesthetics of patients, it is shown in this review how utilizing tissue engineering and cell transplantation, regenerative medicine can provide advancements in hearing and ear aesthetics to fit different patients' needs.

Tissue engineering in otorhinolaryngology: A knowledge-based analysis

Objective

To analyze the impact, performance, degree of specialization, and collaboration patterns of the worldwide scientific production on tissue engineering in otorhinolaryngology at the level of countries and institutions.

Methods

Two different techniques were used, performance and science mapping analyses, using as samples all the available documents regarding tissue engineering focused on otorhinolaryngology applications. The dataset was retrieved from the Core Collection of the Web of Science database from 1900 to 2020. Social structure was analyzed using science mapping analysis with VOSviewer software.

Results

The United States was the main producer, followed by Germany, and Japan. Malaysia and Germany had the highest Relative Specialization Index, indicating their greater relative interest in this area compared to other countries. The social structure analysis showed that the United States and Germany had significant co-authorship relationships with other countries. The University of California System, Kyoto University, and Harvard University were the leading institutions producing literature in this field. These latter two institutions showed the largest number of collaborations, although most of them were with institutions within their own country. There was a lack of connections between different communities of research.

Conclusion

The United States is the main country driving progress in this research area, housing the most notable institutions. However, significant collaborations between these research centers are currently lacking. Encouraging greater cooperation among these institutions and their researchers would promote the exchange of knowledge, ultimately facilitating and accelerating advancements in this field.

Biomedical Application of Decellularized Scaffolds

Tissue loss and end-stage organ failure are serious health problems across the world. Natural and synthetic polymer scaffold material based artificial organs play an important role in the field of tissue engineering and organ regeneration, but they are not from the body and may cause side effects such as rejection. In recent years, the biomimetic decellularized scaffold based materials have drawn great attention in the tissue engineering field for their good biocompatibility, easy modification, and excellent organism adaptability. Therefore, in this review, we comprehensively summarize the application of decellularized scaffolds in tissue engineering and biomedicine in recent years. The preparation methods, modification strategies, construction of artificial tissues, and application in biomedical applications are discussed. We hope that this review will provide a useful reference for research on decellularized scaffolds and promote their application tissue engineering.

Cost-effective 3D scanning and printing technologies for outer ear reconstruction: current status

Current 3D scanning and printing technologies offer not only state-of-the-art developments in the field of medical imaging and bio-engineering, but also cost and time effective solutions for surgical reconstruction procedures. Besides tissue engineering, where living cells are used, bio-compatible polymers or synthetic resin can be applied. The combination of 3D handheld scanning devices or volumetric imaging, (open-source) image processing packages, and 3D printers form a complete workflow chain that is capable of effective rapid prototyping of outer ear replicas. This paper reviews current possibilities and latest use cases for 3D-scanning, data processing and printing of outer ear replicas with a focus on low-cost solutions for rehabilitation engineering.

Fabrication of shape-designable cartilage from human induced pluripotent stem cell-derived chondroprogenitors using a cell self-aggregation technique

With the advancement of tissue engineering technologies, implantable materials have been developed for use in facial plastic surgery, including auriculoplasty and rhinoplasty. Tissue-engineered cartilage comprising only cells and cell-produced extracellular matrix is considered valuable as there is no need to consider problems associated with scaffold absorption or immune responses commonly related to conventional artificial materials. However, it is exceedingly difficult to produce large-sized complex shapes of cartilage without the use of scaffolds. In this study, we describe the production of shape-designable cartilage using a novel cell self-aggregation technique (CAT) and chondroprogenitor cells derived from human induced pluripotent stem cells as the source. The method described does not require special equipment such as bio-3D printers, and the produced tissue can be induced into well-matured cartilage with abundant cartilage matrixin vitro. Using CAT, we were able to generate cartilage in the form of rings or tubes with adjustable inner diameter and curvature, over a range of several centimeters, without the use of scaffolds. Thein vitrofabrication of shape-designable cartilage using CAT is a promising development in facial plastic surgery.

Analysis of cognitive framework and biomedical translation of tissue engineering in otolaryngology

Tissue engineering is a relatively recent research area aimed at developing artificial tissues that can restore, maintain, or even improve the anatomical and/or functional integrity of injured tissues. Otolaryngology, as a leading surgical specialty in head and neck surgery, is a candidate for the use of these advanced therapies and medicinal products developed. Nevertheless, a knowledge-based analysis of both areas together is still needed. The dataset was retrieved from the Web of Science database from 1900 to 2020. SciMAT software was used to perform the science mapping analysis and the data for the biomedical translation identification was obtained from the iCite platform. Regarding the analysis of the cognitive structure, we find consolidated research lines, such as the generation of cartilage for use as a graft in reconstructive surgery, reconstruction of microtia, or the closure of perforations of the tympanic membrane. This last research area occupies the most relevant clinical translation with the rest of the areas presenting a lower translational level. In conclusion, Tissue engineering is still in an early translational stage in otolaryngology, otology being the field where most advances have been achieved. Therefore, although otolaryngologists should play an active role in translational research in tissue engineering, greater multidisciplinary efforts are required to promote and encourage the translation of potential clinical applications of tissue engineering for routine clinical use.

Contemporary management of microtia

Microtia techniques have evolved to improve aesthetic outcomes, reduce donor site morbidities, and reduce complications. Patients with microtia commonly have aural atresia associated with conductive hearing loss. We present the evolution of our technique for microtia reconstruction and considerations for hearing management in these patients. Keywords: Microtia, aural atresia, autologous rib reconstruction, contemporary management.