Prevascularized Tracheal Scaffolds Using the Platysma Flap for Enhanced Tracheal Regeneration.

OBJECTIVES: One of the greatest hurdles in tracheal tissue engineering is insufficient vascularization, which leads to delayed mucosal regeneration, inflammation, and restenosis. This study investigated whether a prevascularized segmental tracheal substitute using platysma can enhance tracheal mucosal regeneration. METHODS: Three-dimensional (3D) printed scaffolds with (group M) or without (group S) Matrigel coating were implanted under the feeding vessels of the platysma in New Zealand White rabbits (n = 3) to induce vascularization. After 1 or 2 weeks, tracheal defects were created and vascularized scaffolds with feeders of the platysma were transplanted as rotational flaps. As controls, scaffolds with or without Matrigel coating was transplanted into a tracheal defect without prevascularization. Airway patency and epithelization were examined using a rigid bronchoscope every 2 weeks. Surviving animals were euthanized at 24 weeks, and microcomputed tomography and histological evaluation were performed. RESULTS: Animals with 2 weeks of prevascularization showed longer survival than animals with 0 or 1 weeks of prevascularization regardless of the Matrigel coating. Wider airway patency was observed in group M than group S. Group M showed migration of epithelium over the scaffold from 4 weeks after transplantation and complete coverage with epithelium at 12 weeks, whereas group S showed migration of the epithelium from 14 weeks and incomplete coverage with epithelium even at 24 weeks. CONCLUSION: This two-step method, utilizing the platysma as an in vivo bioreactor, may be a promising approach to achieve long-term survival and enhanced luminal patency. Matrigel coating on the scaffold had a synergistic effect on epithelial regeneration. LEVEL OF EVIDENCE: NA Laryngoscope, 131:1732-1740, 2021.

Relevant biological processes for tissue development with stem cells and their mechanistic modeling: A review.

A potential alternative for tissue transplants is tissue engineering, in which the interaction of cells and biomaterials can be optimized. Tissue development in vitro depends on the complex interaction of several biological processes such as extracellular matrix synthesis, vascularization and cell proliferation, adhesion, migration, death, and differentiation. The complexity of an individual phenomenon or of the combination of these processes can be studied with phenomenological modeling techniques. This work reviews the main biological phenomena in tissue development and their mathematical modeling, focusing on mesenchymal stem cell growth in three-dimensional scaffolds.

The Sharing of Research Data in the Cell & Tissue Engineering Area: Is It a Common Practice?

The availability of research data sets is an important milestone because it can enhance the dynamics of research. This study aims to analyze the PubMed Central repository to determine the availability and type of raw data sets in Cell & Tissue Engineering journals indexed in Journal Citation Reports. The number and types of files were registered. The main finding of this study is that, beyond the mandatory deposit of data in specific repositories that some journals require, the exchange of data as supplementary material in the Cell & Tissue Engineering journals is not a common practice since researchers are still reticent to do so.

The survey on cellular and tissue-engineered therapies in Europe and neighboring Eurasian countries in 2014 and 2015.

BACKGROUND AIMS: With the support of five established scientific organizations, this report, the seventh of its kind, describes activity in Europe for the years 2014 and 2015 in the area of cellular and tissue-engineered therapies, excluding hematopoietic stem cell (HSC) treatments for the reconstitution of hematopoiesis. METHODS: In 2015 [respectively 2014], 205 [276] teams from 32 countries responded to the cellular and tissue-engineered therapy survey; 178 [126] teams reported treating 3686 [2665] patients. RESULTS: Indications were musculoskeletal/rheumatological disorders (32% [33%]), cardiovascular disorders (12% [21%]), hematology/oncology (predominantly prevention or treatment of graft versus host disease and HSC graft enhancement; 20% [20%]), neurological disorders (4% [6%]), gastrointestinal disorders (<1% [1%]) and other indications (31% [20%]). The majority of autologous cells (60% [73%]) were used to treat musculoskeletal/rheumatological (44% [36%]) disorders, whereas allogeneic cells were used mainly for hematology/oncology (61% [68%]). The reported cell types were mesenchymal stromal cells (40% [49%]), chondrocytes (13% [6%]), hematopoietic stem cells (12% [23%]), dermal fibroblasts (8% [3%]), dendritic cells (2% [2%]), keratinocytes (1% [2%]) and others (24% [15%]). Cells were expanded in vitro in 63% [40%] of the treatments, sorted in 16% [6%] of the cases and rarely transduced (<1%). Cells were delivered predominantly as suspension 43% [51%], intravenously or intra-arterially (30% [30%]), or using a membrane/scaffold (25% [19%]). DISCUSSION: The data are compared with those from previous years to identify trends in a still unpredictably evolving field. Perspectives of representatives from plastic surgery practitioners, Iran and ISCT are presented (contributing authors D.A. Barbara, B. Hossein and W.L. Mark, respectively).

Regenerative Endodontic Procedures among Endodontists: A Web-based Survey.

INTRODUCTION: The protocols that endodontists implement for regenerative endodontic procedures (REPs) are unknown. The aim of this study was to examine current REP protocols among practicing endodontists in the United States. METHODS: A Web-based survey was sent to 4060 active members of the American Association of Endodontists (AAE). A total of 850 participants completed the survey, representing a 20.9% response rate. RESULTS: Responses indicated 60% reported having performed REPs; most performed 1 to 3 per year. The most commonly selected source (60.8%) for the clinical protocol was the "AAE Clinical Considerations for a Regenerative Procedure." Time constraints were the most common reason why 92.4% of respondents did not report their REP cases to the AAE.org database; additionally, 15.5% were unaware of it. Almost half (49.8%) of the participants reported they would attempt an REP on a patient of any age. The most commonly used irrigants were >3% sodium hypochlorite at the first appointment and EDTA at the scaffold formation appointment. As the intracanal medicament, 52.2% used calcium hydroxide, whereas 23.5% used triple antibiotic paste. At the scaffold formation appointment, 77.1% used a local anesthetic without a vasoconstrictor, and 94.3% used a blood clot as the scaffold. Mineral trioxide aggregate was the coronal barrier most often selected. Considering factors most likely to encourage the use of REPs in the future, 79.8% reported the availability of good candidates followed by 40.1% who desired better evidence. CONCLUSIONS: Based on the results of this survey, REP protocols appear to be heterogeneous and do not strictly conform to the "AAE Clinical Considerations for a Regenerative Procedure."

Dossier temático: ingeniería de tejidos en odontología / Thematic Dossier: Tissue Engineering in Dentistry

La odontología no se ha marginado de los grandes y rápidos cambios que han tenido las ciencias debido a la globalización. La ingeniería biomédica, la ingeniería de tejidos y la biología molecular, entre otras disciplinas, trabajan conjuntamente para aportar nuevas alternativas terapéuticas que repliquen la anatomía, fisiología y función de los tejidos u órganos afectados por patología, trauma o alteraciones de desarrollo.

Elaboración de un biodiente: enfoque actual y desafíos / Making a Bio-tooth: Current Approaches and Challenges

Antecedentes: El edentulismo es uno de los mayores problemas de salud oral que cause alteraciones fisiológicas, sociales, estéticas, fonéticas y nutricionales. Las terapias actuales para el remplazo dental son artificiales y no satisfacen los requisitos básicos de un diente natural. La bioingeniería de tejidos constituye una alternativa para la sustitución de dientes perdidos. Objetivo: Identificar los enfoques/técnicas disponibles actualmente para obtener un diente completo por bioingeniería (biodiente), así como puntualizar sus desafíos y perspectivas futuras. Métodos: Se realizó una revisión integrativa de la literatura, por medio de las siguientes palabras clave: biodiente, bioingeniería de tejidos, diente entero y células madre. Los años de la búsqueda fueron 2000-2018, en las bases de datos: PubMed, Scopus, EBSCO, Science Direct, Wiley Online Library, Lilacs y Google Académico/Scholar, en inglés y español. Se seleccionaron únicamente artículos y libros de mayor relevancia y pertinencia. Resultados: Se obtuvieron 53 artículos y 10 libros. Para la elaboración de un biodiente se emplean los siguientes métodos: andamios, sin andamios, células madre pluripotentes inducidas, germen de órganos, diente quimérico y estimulación de la formación de la tercera dentición. El tamaño y forma normales del diente, así como la obtención de células epiteliales, son los principales desafíos. Conclusiones: La posibilidad de crear y desarrollar un biodiente en un ambiente oral adulto es cada vez más real gracias a los avances biotecnológicos que ocurren diariamente. Es posible que estos conceptos sean la base de la odontología restauradora en un futuro próximo.

Background: Edentulism is one of the major oral health problems that cause physiological, social, aesthetic, phonetic, and nutritional issues. Current therapies for dental replacement are artificial and do not satisfy the basic requirements of a natural tooth. Tissue bioengineering could be a viable alternative to substitute lost teeth. Objective: To identify current available approaches/techniques to obtain a complete bioengineered tooth (bio-tooth) and to point out future challenges and perspectives. Methods: This was an integrative literature review. Search keywords used were: bio-tooth, tissue bioengineering, whole tooth, stem cells. The search included the years 2000 through 2018, using the databases PubMed, Scopus, EBSCO, Science Direct, Wiley Online Library, Lilacs and Google Scholar, both in English and Spanish. Only relevant and pertinent articles and books were selected. Results: 53 articles and 10 books were obtained. Methods for bio-tooth generation found were: scaffolds, scaffold-free, induced pluripotent stem cells, tooth organ germ, chimeric tooth, and stimulation of third dentition formation. Achieving normal tooth size and shape and obtaining epithelial cells are the main challenges. Conclusions: The possibility of creating and developing a whole bioengineered tooth (bio-tooth) in an adult oral environment is becoming more realistic, considering the daily biotechnological advances. It is possible that these concepts will be the basis of restorative dentistry in a near future.

Hospital Exemption for Advanced Therapy Medicinal Products: Issue in Application in the European Union Member States.

Regulation (EC) 1394/2007 of the European Parliament and the Council on advanced therapy medicinal products and amending Directive 2001/83/EC and Regulation (EC) No 726/2004 allowed the use of non - authorized advanced therapy medicinal products under the certain circumstances. This socalled hospital exemption rule needs to be applied in the each Member State of the European Union individually and for this purpose Member States should provide national procedures and control measures. The aim of this article is to clear up the criteria for hospital exemption listed in Regulation (EC) 1394/2007 and to contrast the difference in implementing hospital exemption rule into national legal regimes on examples of the United Kingdom, Lithuania and Poland.

Evaluación in vitro de la adhesión de células troncales mesenquimales a matrices dentales impresas en tercera dimensión / In vitro Evaluation of the Mesenchymal Stem Cell Adhesion to 3D-Printed Dental Matrices

Antecedentes: En ingeniería de tejidos es fundamental estudiar el sinergismo entre las células troncales mesenquimales y el biomaterial para tener un mayor control sobre los biomiméticos. De esto depende el éxito de tratamientos de lesiones de tamaño crítico.Objetivo: Evaluar la adhesión celular in vitro de células troncales de la pulpa dental humana (CTPD) en matrices impresas con ácido poliláctico {API.).Métodos: Se utilizaron muestras de CTPD criopreservadas y expandidas, cultivadas sobre 24 matrices dentales impresas en 3D con APL, y que se analizaron los días 1, 7 y 15. Se evaluó la fenotipificacion de la CTPD por citometría de flujo y la adhesión celular a la matriz por medio de microscopio electrónico de barrido (SEM). Los datos se agruparon en porcentajes, tanto para el marcador analizado como para la cantidad de células adheridas. Resultados: Las CTPD expresaron positivamente anticuerpos CD73 y CD90 en casi un 100 % y CD 105 en un 56,7 %. Asimismo, expresaron negativamente anticuerpos CD34 y CD45 en más del 98 %. Se observó en SEM que a los 15 días el 99,88 % de las CTPD presentó forma fusiforme o estrellada, lo que significa que estas células se adhirieron a la matriz de APP.Conclusión : El APL no es citotóxico para las CTPD por su composición y características biocompatibles, lo que hizo posible que las células se adhirieran y proliferaran sobre la matriz dental impresa en 3D. Este fue un método in vitro efectivo para emplear en futuros estudios de regeneración de tejidos en odontología.

Background: In tissue engineering it is quite important to study the synergy between mesenchymal stem cells and biomaterials to better control the biomimetic elements. Success in the treatment of critical-size lesions depends strongly on this fact. Objective: To evaluate the in vitro human Dental Pulpal Stem Cell (DPSC) adhesion in printed matrices developed with polylactic acid (PLA). Methods'. Cryopreserved and enlarged DPSC samples were used in the culture of 24 dental 3D-printed matrices developed with PLA that were analyzed on days 1, 7 and 15. The DPSC typification was analyzed with flow cytometry and the cell adhesion to the matrix was analyzed under the scanning electron microscope (SEM). Data were gathered as percentages for both the analyzed marker and the amounts of adhered cells. Results: DPSCs expressed positively the CD73 and CD90 antibodies in almost 100%and the CD 105 in 56.7%. Likewise, DPSCs expressed negatively the CD34 and CD45 in more than 98%. After 15 days it was observed in the SEM that 99.88% of the DPSCs had either a star-like or fusiform shape, which means that they adhered successfully to the PLA matrix. Conclusion: The PLA is not cytotoxic on the DPSCs thanks to its composition and biocompatible features, which allowed the cell adhesion and proliferation in the 3D-printed dental matrix. This in vitro method was effective and should be use in future studies on tissue regeneration in dentistry.

Adult white New Zealand rabbit as suitable model for corneal endothelial engineering.

BACKGROUND: Corneal endothelium engineering is focused in producing transplantable cell sheets to overcome the shortage of corneal graft tissue donors for the treatment of corneal blindness. For this purpose, the use of a proper animal model plays a key role. Corneal parameters of White New Zealand rabbits such as endothelial cell density, central corneal thickness, and corneal diameter decrease with age, similarly as in humans. However, as opposed to humans, they retain the ability to restore their corneal endothelium after injury. Therefore, they are considered as an inappropriate corneal endothelial wound healing model. FINDINGS: Here we analyze the corneal endothelium mitotic ability of White New Zealand rabbits aged 3, 6, 12 and 18 months, 36 and 72 hours after thermal injury. The highest mitotic activity was observed in the 3-month rabbits 36 h after wounding. Rabbits of 12 months registered decreased mitotic activity and those of 18 months did not show mitotic activity 72 h after injury. CONCLUSIONS: These results propose that rabbits of 18 months represent a suitable model for human corneal endothelium engineering research.

The survey on cellular and engineered tissue therapies in Europe in 2012.

Following the coordinated efforts of five established scientific organizations, this report describes activity in Europe for the year 2012 in the area of cellular and engineered tissue therapies, excluding hematopoietic stem cell (HSC) treatments for the reconstitution of hematopoiesis. Three hundred thirteen teams from 33 countries responded to the cellular and engineered tissue therapy survey: 138 teams from 27 countries provided data on 2157 patients, while a further 175 teams reported no activity. Indications were musculoskeletal/rheumatological disorders (36%; 80% autologous), cardiovascular disorders (25%; 95% autologous), hematology/oncology, predominantly prevention or treatment of graft versus host disease and HSC graft enhancement (19%; 1% autologous), neurological disorders (3%; 99% autologous), gastrointestinal disorders (1%; 71% autologous), and other indications (16%; 79% autologous). Autologous cells were predominantly used for musculoskeletal/rheumatological (42%) and cardiovascular (34%) disorders, whereas allogeneic cells were mainly used for hematology/oncology (60%). The reported cell types were mesenchymal stem/stromal cells (49%), HSC (28%), chondrocytes (11%), dermal fibroblasts (4%), keratinocytes (1%), and others (7%). In 51% of the grafts, cells were delivered after ex vivo expansion, whereas cells were transduced or sorted in 10% and 16%, respectively, of the reported cases. Cells were delivered intra-organ (35%), intravenously (31%), on a membrane or gel (15%), or using 3D scaffolds (19%). The data are compared with those collected since 2008 to identify trends in the field and discussed in the light of recent publications and ongoing clinical studies.

Emerging trends and new developments in regenerative medicine: a scientometric update (2000 - 2014).

INTRODUCTION: Our previous scientometric review of regenerative medicine provides a snapshot of the fast-growing field up to the end of 2011. The new review identifies emerging trends and new developments appearing in the literature of regenerative medicine based on relevant articles and reviews published between 2000 and the first month of 2014. AREAS COVERED: Multiple datasets of publications relevant to regenerative medicine are constructed through topic search and citation expansion to ensure adequate coverage of the field. Networks of co-cited references representing the literature of regenerative medicine are constructed and visualized based on a combined dataset of 71,393 articles published between 2000 and 2014. Structural and temporal dynamics are identified in terms of most active topical areas and cited references. New developments are identified in terms of newly emerged clusters and research areas. Disciplinary-level patterns are visualized in dual-map overlays. EXPERT OPINION: While research in induced pluripotent stem cells remains the most prominent area in the field of regenerative medicine, research related to clinical and therapeutic applications in regenerative medicine has experienced a considerable growth. In addition, clinical and therapeutic developments in regenerative medicine have demonstrated profound connections with the induced pluripotent stem cell research and stem cell research in general. A rapid adaptation of graphene-based nanomaterials in regenerative medicine is evident. Both basic research represented by stem cell research and application-oriented research typically found in tissue engineering are now increasingly integrated in the scientometric landscape of regenerative medicine. Tissue engineering is an interdisciplinary field in its own right. Advances in multiple disciplines such as stem cell research and graphene research have strengthened the connections between tissue engineering and regenerative medicine.

The survey on cellular and engineered tissue therapies in Europe in 2011.

Following the coordinated efforts of five established scientific organizations, this report describes the "novel cellular therapy" activity (i.e., cellular treatments excluding hematopoietic stem cells [HSC] for the reconstitution of hematopoiesis) in Europe for the year 2011. Two hundred forty-six teams from 35 countries responded to the cellular therapy survey, 126 teams from 24 countries provided data on 1759 patients using a dedicated survey and 120 teams reported no activity. Indications were musculoskeletal/rheumatological disorders (46%; 99% autologous), cardiovascular disorders (22%; 100% autologous), hematology/oncology, predominantly including the prevention or treatment of graft-versus-host disease (18%; 2% autologous), neurological disorders (2%; 83% autologous), gastrointestinal (1%; 68% autologous), and other indications (12%; 77% autologous). Autologous cells were used predominantly for musculoskeletal/rheumatological (58%) and cardiovascular (27%) disorders, whereas allogeneic cells were used mainly for hematology/oncology (84%). The reported cell types were mesenchymal stem/stromal cells (56%), HSC (23%), chondrocytes (12%), dermal fibroblasts (3%), keratinocytes (2%), and others (4%). In 40% of the grafts, cells were delivered following ex vivo expansion, whereas cells were transduced or sorted, respectively, in 3% and 10% of the reported cases. Cells were delivered intraorgan (42%), intravenously (26%), on a membrane or gel (16%), or using 3D scaffolds (16%). Compared to last year, the number of teams participating in the dedicated survey doubled and, for the first time, all European Group for Blood and Marrow Transplantation teams reporting information on cellular therapies completed the extended questionnaire. The data are compared with those collected since 2008 to identify trends in the field. This year's edition specifically focuses on cardiac cell therapy.

Cyclic loading of growing tissue in a bioreactor: mathematical model and asymptotic analysis.

A simplified 2D mathematical model for tissue growth within a cyclically-loaded tissue engineering scaffold is presented and analyzed. Such cyclic loading has the potential to improve yield and functionality of tissue such as bone and cartilage when grown on a scaffold within a perfusion bioreactor. The cyclic compression affects the flow of the perfused nutrient, leading to flow properties that are inherently unsteady, though periodic, on a timescale short compared with that of tissue proliferation. A two-timescale analysis based on these well-separated timescales is exploited to derive a closed model for the tissue growth on the long timescale of proliferation. Some sample numerical results are given for the final model, and discussed.

Hurdles in tissue engineering/regenerative medicine product commercialization: a pilot survey of governmental funding agencies and the financial industry.

The Tissue Engineering and Regenerative Medicine International Society of the Americas (TERMIS-AM) Industry Committee conducted a semiquantitative opinion survey in 2010 to delineate potential hurdles to commercialization perceived by the TERMIS constituency groups that participate in the stream of technology commercialization (academia, start-up companies, development-stage companies, and established companies). A significant hurdle identified consistently by each group was access to capital for advancing potential technologies into development pathways leading to commercialization. A follow-on survey was developed by the TERMIS-AM Industry Committee to evaluate the financial industry's perspectives on investing in regenerative medical technologies. The survey, composed of 15 questions, was developed and provided to 37 investment organizations in one of three sectors (governmental, private, and public investors). The survey was anonymous and confidential with sector designation the only identifying feature of each respondent's organization. Approximately 80% of the survey was composed of respondents from the public (n=14) and private (n=15) sectors. Each respondent represents one investment organization with the potential of multiple participants participating to form the organization's response. The remaining organizations represented governmental agencies (n=8). Results from this survey indicate that a high percentage (<60%) of respondents (governmental, private, and public) were willing to invest >$2MM into regenerative medical companies at the different stages of a company's life cycle. Investors recognized major hurdles to this emerging industry, including regulatory pathway, clinical translation, and reimbursement of these new products. Investments in regenerative technologies have been cyclical over the past 10-15 years, but investors recognized a 1-5-year investment period before the exit via Merger and Acquisition (M&A). Investors considered musculoskeletal products and their top technology choice with companies in the clinical stage of development being the most preferred investment targets. All sectors indicated a limited interest in early-stage start-up companies potentially explaining why start-up companies have struggled to access to capital and investors based their investment on the stage of a company's life cycle, reflecting each sector's risk tolerance, exit strategy, time of holding an investment, and investment strategy priorities. Investors highlighted the limited number of regenerative medical companies that have achieved commercial status as a basis for why public investors have been approached by so few companies. Based on respondents to this survey, regenerative medical sponsors seeking capital from the financial industry must keep the explanation of their technology simple, since all sectors considered regenerative medical technology as difficult to evaluate. This survey's results indicate that under the current financial environment, many regenerative medical companies must consider codevelopment or even M&A as nondilutive means of raising capital. The overall summary for this survey highlights the highly varied goals and motivations for the various sectors of the government and financial industries.

The survey on cellular and engineered tissue therapies in Europe in 2010.

Following the coordinated efforts of five established scientific organizations, this report describes the novel cellular therapy activity in Europe for the year 2010. One hundred six teams from 27 countries responded to the cellular therapy survey, 69 teams from 21 countries provided data on 1010 patients using a dedicated survey; 37 teams reported no activity. These data were combined with an additional 260 records reported by 37 teams in 15 countries to the standard European group for Blood and Marrow Transplantation (EBMT) database. Indications were graft-vs.-host-disease (GvHD; 26%; 11% autologous), musculoskeletal disorders (25%; 93% autologous), cardiovascular disorders (20%; 100% autologous), epithelial disorders (16%; 44% autologous), autoimmune diseases (11%; 55% autologous), and neurological disorders (2%; 62% autologous). Autologous cells were predominantly used for musculoskeletal (39%) and cardiovascular (32%) disorders, whereas allogeneic cells were mainly used for GvHD (58%) and epithelial disorders (23%). The reported cell types were mesenchymal stem/stromal cells (MSC; 49%), hematopoietic stem cells (28%), chondrocytes (10%), dermal fibroblasts (4%), keratinocytes (1%), and others (8%). In 63% of the grafts, cells were delivered following ex vivo expansion, whereas cells were transduced or sorted respectively in 10% or 28% of the reported cases. Cells were delivered intraorgan (45%), intravenously (31%), on a membrane or gel (20%) or using 3D scaffolds (4%). Compared with last year, the number of teams adopting the dedicated survey was 1.25-fold higher and, with few exceptions, the collected data confirmed the captured trends. This year's edition specifically discusses scientific, clinical, regulatory, and commercial aspects related to the use of cell therapy for the repair of cartilage defects.

Analysis of attitudes toward the source of progenitor cells in tissue-engineered products for use in burns compared with other disease states.

The first trials using progenitor cells to improve burn wound healing are beginning. However, there remains a paucity of data on patients' opinions of the source of stem cells. In this study, 279 patients attending plastic surgery/burns outpatient and medical outpatient clinics were questioned to assess willingness to accept a tissue-engineered skin product derived from a variety of sources. Levels of acceptance for the use of progenitor cells derived from these sources for treatment across a range of disease states (burns, Parkinson's disease, diabetes, and for cosmetic use) were also assessed. Overall, 80% of those questioned would accept a tissue-engineered product. Autologous cells were the preferred choice of cells (acute burns 94%, diabetes 95%, Parkinson's 93.9%). Allogeneic cells were still widely accepted (acute burns 67%, diabetes 66.7%, Parkinson's 69.2%). There was no difference observed between plastic surgical patients and medical patients in acceptance of cell therapy for burns, Parkinson's disease, or diabetes. There is good potential acceptance for the use of both autologous and allogeneic cells for the treatment of acute burns and burns' scarring as well as in diabetes and Parkinson's disease. Disease state does not appear to influence overall acceptability and choice of cells.