Tissue Engineering in Otorhinolaryngology

Abstract

Tissue engineering is a field of research with interdisciplinary cooperation between clinicians, cell biologists, and materials research scientists. Many medical specialties apply tissue engineering techniques for the development of artificial replacement tissue. Stages of development extend from basic research and preclinical studies to clinical application. Despite numerous established tissue replacement methods in otorhinolaryngology, head and neck surgery, tissue engineering techniques opens up new ways for cell and tissue repair in this medical field. Autologous cartilage still remains the gold standard in plastic reconstructive surgery of the nose and external ear. The limited amount of patient cartilage obtainable for reconstructive head and neck surgery have rendered cartilage one of the most important targets for tissue engineering in head and neck surgery. Although successful in vitro generation of bioartificial cartilage is possible today, these transplants are affected by resorption after implantation into the patient. Replacement of bone in the facial or cranial region may be necessary after tumor resections, traumas, inflammations or in cases of malformations. Tissue engineering of bone could combine the advantages of autologous bone grafts with a minimal requirement for second interventions. Three different approaches are currently available for treating bone defects with the aid of tissue engineering: (1) matrix-based therapy, (2) factor-based therapy, and (3) cell-based therapy. All three treatment strategies can be used either alone or in combination for reconstruction or regeneration of bone. The use of respiratory epithelium generated in vitro is mainly indicated in reconstructive surgery of the trachea and larynx. Bioartificial respiratory epithelium could be used for functionalizing tracheal prostheses as well as direct epithelial coverage for scar prophylaxis after laser surgery of shorter stenoses. Before clinical application animal experiments have to prove feasability and safety of the different experimental protocols. All diseases accompanied by permanently reduced salivation are possible treatment targets for tissue engineering. Radiogenic xerostomia after radiotherapy of malignant head and neck tumors is of particular importance here due to the high number of affected patients. The number of new diseases is estimated to be over 500,000 cases worldwide. Causal treatment options for radiation-induced salivary gland damage are not yet available; thus, various study groups are currently investigating whether cell therapy concepts can be developed with tissue engineering methods. Tissue engineering opens up new ways to generate vital and functional transplants. Various basic problems have still to be solved before clinically applying in vitro fabricated tissue. Only a fraction of all somatic organ-specific cell types can be grown in sufficient amounts in vitro. The inadequate in vitro oxygen and nutrition supply is another limiting factor for the fabrication of complex tissues or organ sys...

Hemoglobin Regulates the Metabolic, Synthetic, Detoxification, and Biotransformation Functions of Hepatoma Cells Cultured in a Hollow Fiber Bioreactor

“…The entire HF bioreactor system (Fig. 1A) 2 at the sinusoid inlet is *65 mm Hg). In the HF bioreactor system, the cell culture medium was continuously pumped from the reservoir bottle to the HF cartridge (i.e., through the lumen of individual HFs), delivering nutrients and O 2 to hepatocytes maintained within the ECS of the HF bioreactor while carrying away metabolic by-products.…”

“…[1][2][3][4] It is well known that O 2 is sparingly soluble in the aqueous medium (*0.2 mmol/L at 1 atm air, 378C). As a result, the cell culture medium in most cell culture systems need to be oxygenated to supraphysiological levels (>160 mm Hg) to deliver enough O 2 to cultured cells, which results in a portion of the cultured cells being exposed to hyperoxic conditions.…”

Wnt signaling in lung organogenesis

“…The larynx is a common target for reconstructive surgery and reparative and signaling mechanisms have been reviewed in the regenerative medicine literature. 3,4 Although the proximal respiratory system plays a critical role in lung diseases that are a direct consequence of environmental exposures as well as those that are exacerbated by environmental triggers, the relative lack of information regarding roles for Wnt/β-catenin in specification and specialization of these prevents further consideration in this review.…”

“…The larynx is a common target for reconstructive surgery and reparative and signaling mechanisms have been reviewed in the regenerative medicine literature. 3,4 Although the proximal respiratory system plays a critical role in lung diseases that are a direct consequence of environmental exposures as well as those that are exacerbated by environmental triggers, the relative lack of information regarding roles for Wnt/β-catenin in specification and specialization of these prevents further consideration in this review.The distal respiratory system is divided into the conducting airway and alveolar regions. The airway is comprised of a series of dichotomously branched tubes that decrease in caliber from proximal (trachea), through the central airways (bronchi, bronchial and bronchioles) to the distal region (terminal and respiratory bronchioles).…”

Overview of Tracheal Tissue Engineering: Clinical Need Drives the Laboratory Approach

“…), the purpose of this review is to give an in-depth view of tracheal tissue engineering. Many excellent trachea tissue engineering reviews exist, 1,3,5,11,84 but the focus is either clinical or experimental. The purpose of this review is to combine both aspects, and to highlight studies with approaches that are clinically translatable.…”