30 research outputs found
MOLD-SHAPED, NANOFIBER SCAFFOLD-BASED CARTILAGE ENGINEERING USING HUMAN MESENCHYMAL STEM CELLS AND BIOREACTOR
Background Mesenchymal stem cell (MSC)-based tissue engineering is a promising future alternative to autologous cartilage grafting. This study evaluates the potential of using MSCs, seeded into electrospun, biodegradable polymeric nanofibrous scaffolds, to engineer cartilage with defined dimensions and shape, similar to grafts used for subcutaneous implantation in plastic and reconstructive surgery. Materials and methods Human bone marrow derived MSCs seeded onto nanofibrous scaffolds and placed in custom-designed molds were cultured for up to 42 days in bioreactors. Chondrogenesis was induced with either transforming growth factor-β1 (TGF-β1) alone or in combination with insulin-like growth factor-I (IGF-I). Results Constructs exhibited hyaline cartilage histology with desired thickness and shape as well as favorable tissue integrity and shape retention, suggesting the presence of elastic tissue. Time-dependent increase in cartilage matrix gene expression was seen in both types of culture; at Day 42, TGF-β1/IGF-I treated cultures showed higher collagen type II and aggrecan expression. Both culture conditions showed significant time-dependent increase in sulfated glycosaminoglycan and hydroxyproline contents. TGF-β1/IGF-I treated samples were significantly stiffer; with equilibrium compressive Young’s modulus values reaching 17 kPa by Day 42. Conclusions The successful ex vivo development of geometrically defined cartilaginous construct using customized molding suggests the potential of cell-based cartilage tissue for reconstructive surgery
Ampelographic characterisation of grapevine accessions denominated 'Refošk', 'Refosco', 'Teran' and 'Terrano' (Vitis vinifera L.) from Slovenia, Croatia and Italy
Grapevines denominated 'Refošk', 'Refosco', 'Teran' and 'Terrano have been cultivated in the area of western Slovenia, north-western Croatia and north-eastern Italy for centuries. Despite historical documents reporting the longstanding tradition of grapevine cultivation and winemaking, the denomination and origin of these varieties is still questionable. The aims of this work were to study the genetic identity and relationship of the grapevine accessions denominated 'Refošk', 'Refosco', 'Teran' and 'Teranno' that have been traditionally cultivated in Slovenia, Croatia and Italy. For this purpose, 9 SSR loci were analysed to fingerprint 53 accessions with denominations or similar true-to-type morphologies of 'Refošk' and 'Teran'. The grapevine variety 'Refošk' cultivated in Slovenia and most accessions denominated 'Teran' in Croatia showed identical genotypes in all analysed SSR markers, and can therefore be used as synonyms. Five accessions showed identical genotypes to 'Refosco dal peduncolo rosso' variety, however five other genotyped accessions suggested individual profiles, and can be characterized as clonal mutants of true-to-type 'Refošk'/'Teran'. Accessions 'Sladki Teran' and 'Ref5/31' shared 56 % and 61 % of the alleles with true-to-type profiles of 'Refošk'/'Teran' and their parentage analysis strongly suggested a full-siblings relationship. Obtained results contribute to the understanding of the genetic diversity of grapevine varieties cultivated in this part of Europe
Human palatine tonsil: a new potential tissue source of multipotent mesenchymal progenitor cells
INTRODUCTION: Mesenchymal progenitor cells (MPCs) are multipotent progenitor cells in adult tissues, for example, bone marrow (BM). Current challenges of clinical application of BM-derived MPCs include donor site morbidity and pain as well as low cell yields associated with an age-related decrease in cell number and differentiation potential, underscoring the need to identify alternative sources of MPCs. Recently, MPC sources have diversified; examples include adipose, placenta, umbilicus, trabecular bone, cartilage, and synovial tissue. In the present work, we report the presence of MPCs in human tonsillar tissue. ----- METHODS: We performed comparative and quantitative analyses of BM-MPCs with a subpopulation of adherent cells isolated from this lymphoid tissue, termed tonsil-derived MPCs (T-MPCs). The expression of surface markers was assessed by fluorescent-activated cell sorting analysis. Differentiation potential of T-MPCs was analyzed histochemically and by reverse transcription-polymerase chain reaction for the expression of lineage-related marker genes. The immunosuppressive properties of MPCs were determined in vitro in mixed lymphocyte reactions. ----- RESULTS: Surface epitope analysis revealed that T-MPCs were negative for CD14, CD31, CD34, and CD45 expression and positive for CD29, CD44, CD90, and CD105 expression, a characteristic phenotype of BM-MPCs. Similar to BM-MPCs, T-MPCs could be induced to undergo adipogenic differentiation and, to a lesser extent, osteogenic and chondrogenic differentiation. T-MPCs did not express class II major histocompatibility (MHC) antigens, and in a similar but less pronounced manner compared with BM-MPCs, T-MPCs were immunosuppressive, inhibiting the proliferation of T cells stimulated by allogeneic T cells or by non-specific mitogenic stimuli via an indoleamine 2,3-dioxygenase-dependent mechanism. ----- CONCLUSION: Human palatine T-MPCs represent a new source of progenitor cells, potentially applicable for cell-based therapies
Activin A expression regulates multipotency of mesenchymal progenitor cells
INTRODUCTION. Bone marrow (BM) stroma currently represents the most common and investigated source of mesenchymal progenitor cells (MPCs); however, comparable adult progenitor or stem cells have also been isolated from a wide variety of tissues. This study aims to assess the functional similarities of MPCs from different tissues and to identify specific factor(s) related to their multipotency. METHODS. For this purpose, we directly compared MPCs isolated from different adult tissues, including bone marrow, tonsil, muscle, and dental pulp. We first examined and compared proliferation rates, immunomodulatory properties, and multidifferentiation potential of these MPCs in vitro. Next, we specifically evaluated activin A expression profile and activin A:follistatin ratio in MPCs from the four sources. RESULTS. The multidifferentiation potential of the MPCs is correlated with activin A level and/or the activin A:follistatin ratio. Interestingly, by siRNA-mediated activin A knockdown, activin A was shown to be required for the chondrogenic and osteogenic differentiation of MPCs. These findings strongly suggest that activin A has a pivotal differentiation-related role in the early stages of chondrogenesis and osteogenesis while inhibiting adipogenesis of MPCs. CONCLUSIONS. This comparative analysis of MPCs from different tissue sources also identifies bone marrow-derived MPCs as the most potent MPCs in terms of multilineage differentiation and immunosuppression, two key requirements in cell-based regenerative medicine. In addition, this study implicates the significance of activin A as a functional marker of MPC identity.National Institute of Arthritis, and Musculoskeletal and Skin Diseases; National Institutes of Health (ZO1 AR 41131, 01 DE019156-01
Regeneratives Potential von mesenchymalen Stammzellen und (de-)differenzierten Chondrozyten in einem bovinen Knorpeldefektmodell in vitro
Volumetric facelift: Evaluation of rhytidectomy with alloplastic augmentation
Objectives: Facial aging occurs as a result of soft tissue atrophy and resorption of the bony skeleton, which results in a loss of soft tissue volume and laxity of the overlying skin. Volumetric augmentation is a key component of facial rejuvenation surgery, and should be considered of equal importance to soft tissue lifting. Augmentation can be accomplished with synthetic fillers, autologous grafts, soft tissue repositioning techniques, and/or alloplastic implants. Only alloplastic implants, however, provide truly long-term volumetric correction. To date, there have been no large series dealing with the complications and results of implantation performed concurrently with rhytidectomy, which we have termed volumetric rhytidectomy. We present our experience with 100 patients treated with a combination of malar and chin implants and rhytidectomy, compared to 200 patients who underwent rhytidectomy alone. Methods: The authors performed a retrospective review of patients treated with a combination of silicone malar and chin augmentation with rhytidectomy versus patients treated with rhytidectomy alone. Both groups of patients underwent close postoperative evaluation at 3 days, 1 week, 2 weeks, and 1 month. All patients were surveyed at 6 months to assess aesthetic satisfaction. Complication rates were noted and tabulated. Statistical analysis was performed to evaluate for any differences in the two groups. Results: Between 2002 and 2006, 100 patients underwent malar and chin implantation along with rhytidectomy; 200 patients underwent rhytidectomy alone. In the first group, there were a total of 6 cases in which implant removal was necessary, and 2 cases in which revision was required. There were no statistically significant differences (p \u3c 0.05) observed between the two groups with respect to major or minor hematoma, seroma, infection, sensory nerve injury, facial nerve injury, hypertrophic scarring, dehiscence, skin sloughing, or revision. Conclusions: Volumetric rhytidectomy reliably augments the malar and mental areas, allows for subtle skeletal contouring, and results in successful rejuvenation. Rhytidectomy is relatively safe to perform concurrently with silicone augmentation, and does not result in an increased complication rate as compared to rhytidectomy alone. © 2010 Annals Publishing Company. All rights reserved
Does suture material and technique really matter? Lessons learned from 800 consecutive blepharoplasties
Volumetric facelift: Evaluation of rhytidectomy with alloplastic augmentation
Objectives: Facial aging occurs as a result of soft tissue atrophy and resorption of the bony skeleton, which results in a loss of soft tissue volume and laxity of the overlying skin. Volumetric augmentation is a key component of facial rejuvenation surgery, and should be considered of equal importance to soft tissue lifting. Augmentation can be accomplished with synthetic fillers, autologous grafts, soft tissue repositioning techniques, and/or alloplastic implants. Only alloplastic implants, however, provide truly long-term volumetric correction. To date, there have been no large series dealing with the complications and results of implantation performed concurrently with rhytidectomy, which we have termed volumetric rhytidectomy. We present our experience with 100 patients treated with a combination of malar and chin implants and rhytidectomy, compared to 200 patients who underwent rhytidectomy alone. Methods: The authors performed a retrospective review of patients treated with a combination of silicone malar and chin augmentation with rhytidectomy versus patients treated with rhytidectomy alone. Both groups of patients underwent close postoperative evaluation at 3 days, 1 week, 2 weeks, and 1 month. All patients were surveyed at 6 months to assess aesthetic satisfaction. Complication rates were noted and tabulated. Statistical analysis was performed to evaluate for any differences in the two groups. Results: Between 2002 and 2006, 100 patients underwent malar and chin implantation along with rhytidectomy; 200 patients underwent rhytidectomy alone. In the first group, there were a total of 6 cases in which implant removal was necessary, and 2 cases in which revision was required. There were no statistically significant differences (p \u3c 0.05) observed between the two groups with respect to major or minor hematoma, seroma, infection, sensory nerve injury, facial nerve injury, hypertrophic scarring, dehiscence, skin sloughing, or revision. Conclusions: Volumetric rhytidectomy reliably augments the malar and mental areas, allows for subtle skeletal contouring, and results in successful rejuvenation. Rhytidectomy is relatively safe to perform concurrently with silicone augmentation, and does not result in an increased complication rate as compared to rhytidectomy alone. © 2010 Annals Publishing Company. All rights reserved
Does suture material and technique really matter? Lessons learned from 800 consecutive blepharoplasties
OBJECTIVES: The purpose of this study was to evaluate established suture materials and techniques for blepharoplasty closure and evaluate for any differences in rates of complications between these groups. STUDY DESIGN AND METHODS: This was a prospective study of a large sequential series of patients undergoing upper blepharoplasty who were treated by the same senior author over a 5-year period. Patients were assigned one of four techniques for closure of the incision based on the senior author\u27s experience. After 6 weeks, rates of complications and revisions were noted and addressed. Satisfaction rates were noted at 3 months. RESULTS: In the group whose incisions were closed with running subcuticular polypropylene (Prolene), 5 (2.5%) presented with milia, and 11 (5.5%) had a standing cone deformity (SCD). Use of running cutaneous locked Prolene resulted in 8 patients (17%) with milia and 2 patients (4.4%) requiring revision of a SCD. Use of a running 6-0 plain gut suture resulted in 12 patients (6.7%) with milia and 5 patients (2.8%) with unsightly scarring. In the group whose incisions were closed with running 6-0 fast-absorbing gut, 10 patients (2%) presented with milia, and there were no scar revisions. There were statistically significant differences between the groups with respect to formation of milia, scarring, and persistent erythema (P \u3c .008). CONCLUSIONS: Blepharoplasty is a safe and effective procedure that can be performed successfully with several established techniques. In our experience, closure with two interrupted 6-0 Prolene sutures and a running 6-0 fast-absorbing gut resulted in the lowest rates of complications and revisions. © The American Laryngological, Rhinological & Otological Society, Inc