XI Brazilian Association of Cell and Gene Therapy (ABTCel-Gen) Meeting Abstract Submission Now Open
ABSTRACTS
Later Poster 2021
Publish in a supplemental version of Cytotherapy, the official journal of ISCT
ABTCel-Gen Meeting/ ISCT South & Central America Regional Forum Abstract Supplement digi-edition:
https://abtcel-genisctregionalabstracts.elsevierdigitaledition.com/
ABTCel-Gen Meeting/ ISCT South & Central America Regional Forum Abstract Supplement digi-edition:
https://abtcel-genisctregionalabstracts.elsevierdigitaledition.com/
Later Poster 2021
3D DIGITAL PLANNING OF BONE DEFECT RECONSTRUCTION FOR POSSIBLE STEM CELL THERAPY
S Burgo1, TB Soares1, MP Leão2, JC Zielak1
1 Universidade Positivo
2 Curytiba Biotech
Background: In the last few years, CAD/CAM based technologies have been more accessible to clinicians who need to implement digital plannings in order to perform treatments involving printing or milling of appliances such as surgical guides, prosthesis and biomodels. CAD (Computer Aided Design) is a process that involves the design of a 3D model developed in a software based on digital files; CAM (Computer Aided Manufacturing) is the materialized product, obtained by milling or printing, of the 3D Model from CAD. Methods: The purpose of the present work was to present the planning of a bone graft technique applied to a virtual maxillary defect to allow the insertion of biomaterials and stem cells to an intended augmentation. Results and Conclusion: Biomodels have been widely used in surgical reconstructions in order to recreate the bone defects, facilitating planning and biomaterials adaptation such as bone blocks and cell barriers. Especially designed softwares for dental surgical plannings (eg. Nemotec®) allow the analysis of bone defects contributing to ideal dental implant plannings ( Fig. 1A-E). A virtual bone graft, anatomically adapted to the bone defect, can be designed (Fig. 1F-H). All 3D models designed in the software can be exported as a *.STL file and can be manufactured by milling or printing through CAM process. With all this available technology it is possible to print a bone graft block and associated it with stem cells, materials that could be easily adapted to the bone defect by a surgeon. Mixing cells and biomaterials, besides having a scaffold as a template for bone ingrowth is a possible and real surgical strategy, while the bone graft could develop osteogenic properties, which could contribute significantly for the new bone formation.
ASSOCIATION OF IMMUNE BIOMARKERS AND ORAL BIOFILM IN THE INDUCTION OF DENTAL PAPILLA GROWTH BY SUCTION TECHNIQUE
Xavier.D.G1, Pinheiro. M.D.S1, Oliveira.D.R1, Fraga.L.A.O1
1 Universidade Ferderal de Juiz de Fora - Campus Governador Valadares
Introduction: Gingival recession is highly prevalent among the low-income population and is one of the main causes of pain, tooth loss, and esthetic deficiency. There are still no reports in the literature of non-surgical techniques to repair this damage. Due to this gingival area‘s small vascularization, the proposed treatment alternatives have presented low success rates. From observations made in several denture wearers, it was possible to verify the important growth of palate epithelial tissue into the suction chambers in patients with this prosthetic device. In the literature, several studies show that this epithelium has no capacity for malignant transformation. Thus, our group proposes using an alternative and innovative approach of low-cost and non-invasive treatment, using the suction plate technique, for gingival neoformation and resolution of recession situations. Methods: The purpose of this study is to evaluate 30 individuals separated into group 01 (control) and group 02 (patients with gingival retraction). The patients will be molded with alginate, and then suction plates will be made, which should be used for 28 days. Crevicular fluid samples will be collected at 6 times (day 0, 1, 7, 14, 21, 28) and stored at -80°C until used. We will analyze cytokines, chemokines, growth factors and, gene expression of antioxidant enzymes, and the local microbiota at each collection time. A pilot study has already been conducted for 28 days. The results of this follow-up will be presented. Results: Case follow-up of a 38-year-old patient, leucoderma, with no history of morbidities, with the gingival recession in the upper incisor region, where he was wearing dental implants, complaining of functional and aesthetic problems was submitted to the use of suction plate for 28 days. During the entire papilla growth induction process by suction, we observed reddish areas typical of inflammatory tissue, edema, and sometimes bleeding. This confirms the viability of the technique. Conclusion: The preliminary results obtained provide positive subsidies for study designs that will underpin public health policies, aiming to establish more effective, less costly, and non-invasive measures for the control and clinical management of patients with gingival recession.
CHARACTERIZATION AND BIOBANKING OF BOVINE MESENCHYMAL STROMAL/STEM CELLS
E Iglesias1, G Ávila2, A Algorta2, N Vázquez3, W Pérez3, K Yaneselli21 Unidad de Inmunología en Inmunoterapia, Departamento de Patobiología, Facultad de Veterinaria, Universidad de la República (Udelar), Uruguay
2 Unidad de Inmunología en Inmunoterapia, Departamento de Patobiología, Facultad de Veterinaria, Universidad de la República (Udelar), Uruguay
3 Unidad de Anatomía, Departamento de Biociencias, Facultad de Veterinaria, Universidad de la República (Udelar), Uruguay
Introduction: The mesenchymal stromal/stem cells (MSCs) are multipotent cells with capacity of differentiating into mesodermal cells and have moderate capacity of self-renewal. These cells have been isolated from domestic species for therapy purposes as well as industrial purposes such as synthetic meat production. Objective: Characterization and cryopreservation of bovine adipose tissue-derived MSCs (AD-MSCs). Materials and Methods: The AD-MSCs were isolated from bovine (Bos taurus) adipose tissue (n=11). Cells were culture in flasks with standard growing medium. The AD-MSCs (n=3) were seeded at a density of 5 x10³ /cm² in plates to study cell proliferation by doubling time (DT) from passage 2 to 6. Clonogenic capacity was studied by Colony Forming Units - Fibroblasts (CFU-F) assay, seeding cells at a density of 1 x 10³ /cm² by triplicate. Multipotency was confirmed by in vitro tridifferentiation assay. For biobanking, at 80-90% cell confluence was cryopreserved at -80°C. Results: A preliminary characterization by tridifferentiation was obtained, the isolated cells showed fibroblastic morphology and plastic adherence. Cells were able to form colonies (range 15 to 36 colonies) without differences (p=0.1886) throughout passages. Doubling time increased significantly along the passages with a range 1.5 to 4.7 days (p=0.0201), showing a notorious increase between passage 4 and 5 (p=0.0386). Conclusion: Standard characterization from domestic animals was achieved by in vitro tridifferentiation as gold standard assay. A biobank was conformed in the academic unit that will allow future research on therapeutic or industrial aspects. As a perspective, it is characterizing all isolates.
DIFFERENT CELL CULTURE CONDITIONS INFLUENCE PHENOTYPE CHARACTERISTICS IN VITRO OF HUMAN STEM CELLS FROM DENTAL APICAL PAPILLA
LM Macedo1, LM Macedo1, LAG Silva1, ACG Silva1, MC Valadares1, EM Lima1, GT Kitten2, CH Castro1, E Gava11 Federal University of Goiás
2 Federal University of Minas Gerais
Background: Dental stem cells from dental apical papilla (SCAPs) can differentiate into osteoblasts, odontoblasts, adipocytes and neural cells. It is essential to understand the intrinsic function and reparative conditions of these cells, since effective cell therapies to repair tooth structures need to be improved. For this, a more suitable in a vitro culture system that maintains stem cells in a naive, multipotent state is crucial. We sought to evaluate how different cell culture conditions may influence phenotype characteristics in vitro of SCAPs. Methods: Apical papilla was cut into small fragments (explants) and submitted to varying concentrations of cell-dissociation enzymes: type I Collagenase, Collagenase + Dispase II and TrypLE™ Express. Expression of stem cell markers were analyzed by flow cytometry. Cell migration from explants and the existence of stem cell niches was analyzed in three-dimensional collagen gel scaffold. To evaluate the influence of human serum (HS) supplementation, SCAPs were maintained in DMEM/F12 supplemented with 10% HS, or 10% fetal bovine serum (FBS). Results: Low concentration of Collagenase (0.5mg/mL) maintained part of the intact extracellular matrix and allowed cell migration and proliferation. SCAPs were positive for CD90, CD146, CD44 and p75NTR, and negative for STRO-1, CD14 and CD19. After every 7 days, the explants were transferred to another dish containing fresh collagen gel. Cells migrated continuously after consecutives passages of the same explant, suggesting the presence of stem cell niches. While SCAPs from the FBS group presented a fibroblast-like mesenchymal population, SCAPs cultivated with HS presented a variable morphology with either fibroblast- or neuronal-like features, plus formed compact spherical clusters. Conclusion: This study provides information which will help to better preserve the phenotype and characteristics of SCAPs in culture. The results provide important information about the in vitro culture of human SCAPs and will have applications in cell therapy and regenerative medicine.
EFFECT OF BONE MARROW CELL TRANSPLANTATION ON INFLAMMATORY PROFILE AND INSULIN RESISTANCE IN ADIPOSE TISSUE IN OVERFED MICE
A.L. Ferreira1, A.A. Thole1, G.P. de Oliveira1, L. de Carvalho11 Rio de Janeiro State University
Obesity is a metabolic disease of global concern which leads to comorbidities such as cardiovascular disease, cancer, and Type 2 diabetes. Obese individuals often exhibit insulin resistance, implying a hyperglycemic state, consistent with diabetes. In this regard, cell therapy with bone marrow cells (BMC) as a way to improving this scenario had been a target of studies nowadays. In literature, BMC is already described by their potential for tissue repair, anti-inflammatory paracrine action, and reestablishment of glycemic levels by their potential for tissue repair, anti-inflammatory paracrine action and reestablishment of glycemic levels in obese animals. Our goal is to evaluate the therapeutic potential of BMC cells over glycemia and insulinemia, as well as the GLUT-4 expression in adipose tissues of obese mice. Obesity induction in mice was done through the litter reduction model during lactation. In order to evaluate the effect of hyperalimentation during lactation, control and obese animal were often evaluated, which the naso-anal length was measured, epididymal fat was weighted and Lee index was accessed. On the 90th post-birthday, we established a control group (CG), overfed group (OG), and the overfed group that received BMC therapy (OG+BMC) (n=6). The glucose tolerance test was assed before and after BMC therapy in all groups. Insulin concentrations were analyzed by insulin plasma dosage and GLUT-4 quantification in adipose tissue was done by western blotting. As result, OG and OG+BMC groups had a significant body weight gain compared to CG (40,64±0,49; OG:48,93±1,07; OG+BMC:51,24±1,03). The glycemic curve was higher in OG group than in CG, obtaining a significant reduction after BMC therapy. Insulinemia was higher in OG than in CG, with significant improvement un OG+BMC group (CG:49,28±1,93; OG: 326,1±31,17; OG+BMC:94,86±24,31). GLUT-4 expression was lower in OG group when compared to CG group, achieving significant improvement with BMC transplantation (CG:7,724±0,3839; OG:3,553±0,3182; OG+BMC:5,233±0,8477). Thus, It is possible to receive the therapeutic potential of BMC in reducing insulin resistance, reducing glycemia, and increasing the expression of GLUT-2 transporter.
EFFECT OF LOW-LEVEL LASER IRRADIATION ON THE BIOLOGICAL ACTIVITY OF DENTAL STEM CELLS CULTURED ON POLYLACTIC ACID SCAFFOLDS
TJS Xavier1, LPB Carvalho2, VG Sabino1, HAO Rocha1, CEB Moura3, CAG Barboza11 Federal University of Rio Grande do Norte, Natal, Brazil
2 Federal University of Paraíba, João Pessoa, Brazil
3 Federal Rural University of Semiarid Region, Mossoró, Brazil
Background: Dental mesenchymal stem cells (dMSCs) have been widely used in tissue engineering due to their self-renewal capacity and multi-lineage potential. Previous studies have showed the positive effect of low-level laser irradiation on dMSCs, emerging as an alternative to stimulate in vitro cell proliferation. This study aimed to evaluate the effect of different doses of laser irradiation on the biological activity of stem cells from human exfoliated deciduous teeth (SHEDs) cultured on polylactic acid (PLA) scaffolds. Methods: SHEDs were isolated and characterized and then cultured on PLA films and irradiated or not (control) with an InGaAlP diode laser (660 nm, 30 mW, continuous action mode), using a screening of energy densities (1; 4; 7.5; 15; 22.5; and 30 J/cm²). Cell proliferation and viability were analysed at 24, 48, and 72 h using the Alamar Blue and Live/Dead assays. Cell morphology was evaluated by scanning electron microscopy (SEM) at 72 h. The evaluation of oxidative stress was performed through the dosages of malondialdehyde (MDA) and glutathione (GSH). Results: Energy densities of 1 J/cm² and 4 J/cm² promoted cell proliferation in all intervals when compared to the control group and to the other irradiated groups. Conversely, high doses of irradiation (22.5 and 30 J/cm²) promoted a significant negative effect on cell proliferation. Cell viability was affected throughout the experiment in groups L22.5 and L30, which presented a higher number of dead cells in the interval of 72 h. The SEM analysis showed a greater cell density in L1 and L4 groups, opposing the SHEDs arranged more sparsely in L22.5 and L30 groups. Regarding oxidative stress, in L1 and L4 groups, there was an increase of GSH levels and reduction of MDA, showing a cytoprotective effect of these doses. In groups L22.5 and L30, there was a reduction of GSH levels and elevation of MDA, corroborating the results of the aforementioned assays. Conclusion: The results indicate that low doses of laser irradiation (1 and 4 J/cm²) promote proliferation of SHEDs on PLA scaffolds, while high doses (22.5 and 30 J/cm²) exert cytotoxic and anti-proliferative effects.
HISTOLOGICAL EVALUATION OF THE USE OF AUTOLOGOUS GRAFTS FROM THE XYPHOID APPENDIX, CARTILAGE AND SUBCONDRAL BONE IN RATS
AF SOARES1, ADP FLORENTINO2, VA SILVA-JUNIOR2, F NARO3, MW TEIXEIRA21 PPGBA / UFRPE
2 DMFA / UFRPE
3 Sapienza University of Rome
Apresentador: ANÍSIO FRANCISCO SOARES
Background: Stem cells have been the target of great interest in cell therapy, with innovative perspectives, as they have the capacity for self-renewal, self-proliferation, differentiation in specialized cell lines and tissue regeneration. of rats. Histologically evaluate the repair process of joint defects, after the use of autologous mesenchymal stem cells in the knee of Wistar rats, obtained through the Rigenera® system. Methods: The present study was carried out after being approved by the Ethics Committee on the Use of Animals, Federal Rural University of Pernambuco, with License 126/2017. The experiments followed institutional guidelines for animal treatment and complied with relevant legislation. Twelve male adult albino rats (Rattus norvegicus, variety, Wistar), clinically healthy, ranging from 300g to 350g, were used. The animals were kept in suitable cages with capacity for 5 animals, under controlled illumination and temperature (12-h light-dark cycle and approximately 23°C), feed and water ad libitum. Full thickness osteochondral defects of 2.5 mm were created bilaterally in all animals. Briefly, a Bard-Parker type scalpel cable mounted with blade # 11 was used and an initial puncture of the bone with the aid of punch, in contra-angle and at right angles to the cortical bone involved were performed. Each animal received stem cell treatment on the left knee and the right knee was used as a contralateral limb. Group 1 MSCs were extracted from the bone tissue of the lesion caused in the animal‘s control limb. For animals in Group 2, MSCs were extracted from a part of the animal‘s own xiphoid appendix. The animals were euthanized 60 days after the surgery, the bone pieces were decalcified and stained for histological analysis. Results: The results showed that in acute fast healing lesions, the use of MSCs favored the formation of a cartilaginous tissue interposed between spongy and compact bone tissue, as well as cartilaginous tissue newly formed in an area of compact bone tissue. Hyaline cartilage remained present in both groups, a relevant feature in the study, in view of being an atypical behavior in the model studied. Conclusions: The results reported are suggestive for a role of micrografts in the promoting the formation of both cartilage and bone with a well structured cellular organization. Also the qualitative analyses on new formed tissues strongly confirm the ability of micrografts to induce cartilage and bone formation.
INFLUENCE OF THE QUORUM SENSING MOLECULE N-(3-OXODODECANOYL)-L-HOMOSERINE LACTONE ON THE VIABILITY OF IFN-Ɣ PRIMED MESENCHYMAL STEM CELLS
M R R Sousa1, T A Silva2, LDC Filiú- Braga3, AE Silva- Carvalho3, FAR Neves3, JL Carvalho2, F Saldanha-Araújo31 University of Brasília, Brasília, DF, Brazil.
2 Catholic University of Brasília, Brasília
3 University of Brasília, Brasília, DF, Brazil
Pseudomonas aeruginosa is an opportunistic pathogen whose virulence and mechanism of interaction with the host are controlled by cell density-dependent signaling molecules, called quorum sensing (QS). This pathogen has two types of QS signaling molecules, such as N-Acyl-homoserine lactones and the 2-heptyl-3-hydroxy-4-quinolone signal from Pseudomonas quinolone. Mesenchymal stem cells (MSCs) have been explored to treat a variety of clinical conditions, especially immune disorders. In this sense, several studies have shown that the priming of MSCs with IFN-γ increases the immunomodulatory property of these cells. In the present study, we investigated the influence of QS N- (3-oxododecanoyl) -L-homoserine (OdDHL) on the biological properties of MSCs submitted or not to priming with IFN-γ. Using the MTT test, we demonstrated that, after 24 and 72 h of cell culture, OdDHL (10, and 50 μM) compromises the viability of CTMs, regardless of priming with INF-γ. By Flow Cytometry, we observed that OdDHL (10 and 50 μM) induces apoptosis in MSCs and that this deleterious effect seems to be more pronounced in IFN- γ primed MSCs. The apoptotic effect was accompanied by a significant increase in the expression of the pro-apoptotic genes BAX and CASP3. Also, OdDHL (10 and 50 μM) was able to induce senescence of MSCs after 48 hours of cell culture in unlicensed groups. Our preliminary data indicate that despite increasing the immunosuppressive potential of MSCs, priming with interferon makes these cells more sensitive to the QS produced in bacterial infections. Keywords: Pseudomonas aeruginosa, quorum sensing, OdDHL, Mesenchymal stem cell, priming.
LOW-LEVEL LASER IRRADIATION INDUCES PROLIFERATION OF PERIODONTAL LIGAMENT STEM CELL CULTURED ON CHITOSAN SCAFFOLDS
VG Sabino1, RB Leite1, EG Nascimento1, CEB Moura2, HAO Rocha1, AA Silva-Júnior1, CAG Barboza11 Federal University of Rio Grande do Norte, Natal, Brazil
2 Federal Rural University of Semiarid Region, Mossoró, Brazil
Backgorund: Low-level laser irradiation (LLLI) has been widely used in regenerative medicine due to its biostimulatory effects, mainly on the metabolism, proliferation and viability of different cell types. LLLI has been identified as a successful tool in tissue engineering protocols, but little is known about its effectiveness in the proliferation of cells grown on the surface of biomaterials. Thus, the hypothesis that LLLI promotes the proliferation of human periodontal ligament stem cells (PDLSCs) cultured in chitosan films was tested in this work. Methods: Chitosan films were prepared by solvent evaporation technique, characterized and submitted to a disinfection protocol. PDLSCs were previously isolated, characterized and later cultivated in four groups: Co (control) - polystyrene plastic surface; Ch (chitosan) - cells grown on the chitosan films; L1 - cells cultured on the chitosan films and irradiated with 1 J/cm²; and L4 - cells grown on the chitosan films and irradiated with 4 J/cm². The irradiations were performed with a diode laser (InGaAIP), with wavelength of 660 nm, power of 30 mW and continuous mode of action. Cell proliferation was evaluated by the Alamar Blue assay at intervals of 24, 48 and 72 h after irradiation, and at 72 h were assessed the cell viability by staining with Annexin V and propidium iodide (PI), the profile of the cell cycle and the Ki67 protein expression by flow cytometry and the cell morphology by scanning electron microscopy (SEM). Results: The Alamar Blue assay showed significant differences between groups at 24 h intervals (L1> Ch, p = 0.0118) and at 48 h (L1> Ch, p = 0.0022; L4> Ch, p = 0.0002; L4> L1, p = 0.0022). The Annexin V/PI assay showed a higher percentage of viable cells in L4 (80.7%) and L1 (77.5%) compared to Ch (63.1%) in 72 h. The immunoexpression of the Ki67 protein was higher in L4 and L1 and these two groups also had a higher percentage of cells in S and G2/M phases. The SEM analysis showed in the Ch group cells with a more rounded morphology and few projections, while in the irradiated groups the cells exhibited a flatter arrangement, with more distributed projections and focal adhesion points, especially in L4. Conclusion: Taken together, the results of this study allowed to conclude that the laser irradiation in the studied parameters, especially with a dose of 4 J/cm², exerts a positive influence on the viability and proliferation of PDLSCs on chitosan films.
PARTICIPATION OF MESENQUIMAL STEM CELLS IN THE PRODUCTION OF COLLAGEN IN DIABETIC RAT WOUNDS
MB Palma1, GBA Cabral-Silva1, FAL Souza1, IMF Melo1, F Naro2, AF Soares11 Rural Federal University of Pernambuco
2 Sapienza University of Rome
Background: Diabetes induces physiological changes in tissues and cells, impairing healing. About 25% of diabetics develop chronic wounds that stagnate in the inflammatory phase and do not complete the healing process. This leads to damage to the surrounding tissue due to the presence of cytotoxic enzymes, free radicals and inflammatory mediators. Collagen is the most abundant protein in the body and the main component of the extracellular matrix. Scar tissue results from the interaction between its synthesis, fixation and degradation. Stem cells are considered to have an important role in tissue regeneration and repair because they differentiate into multiple cell lines, in addition to their paracrine effects. Thus, this work aimed to analyze the quantification of collagen in wounds of diabetic rats treated with mesenchymal stem cells (MSC). Methods: 45 rats (rattus norvegicus albino) with 90 days of age were used and divided into groups: CG (submitted to the wound for 3, 7 and 14 days without treatment with MSC); GCTC (submitted to the wound for 3, 7 and 14 days and treated with CTM); DG (diabetic, submitted to the wound for 3, 7 and 14 days); GDTC (diabetic submitted to the wound for 3, 7 and 14 days and treated with MSC). Diabetes was induced by intraperitoneal administration of streptozotocin at a dosage of 60 mg / kg. The treatment with CTM was done by the local administration of these cells, which were obtained by Rigenera®. For skin collection, the animals were anesthetized with ketamine (80mg / kg) and xylazine (10mg / kg) and euthanized with anesthetic overdose. The skins were fixed, processed for inclusion in paraffin and subjected to Mallory‘s Trichrome stain (collagen stain). 5 slides were used per group and for each time and 5 photos were taken for each slide. The latter were submitted to the GIMP 2.0 program to quantify collagen. The results obtained were subordinated to the statistical test SAS institute 2002. Results: A significant difference was found between the GC 7 and GC 14 groups in relation to the GDTC 3 group. At 7 and 14 days of evolution of the GC healing, it showed less collagen quantification than GDTC 3, showing that, despite the animal being diabetic, collagen production was more effective in less time. Conclusion: Treatment with MSC is able to accelerate the healing process, optimizing the production of collagen essential for the formation of scar tissue.
USE OF MESENQUIMAL STEM CELLS IN THE INDUCTION OF BONE REGENERATION IN RATS
Welma Emidio da da Silva1, AAC TEIXEIRA1, FS COSTA2, ABB COSTA1, VA SLVA-JÚNIOR2, F NARO3, AF SOARES1, MW TEIXEIRA1, FCS LIMA11 Department of Animal Morphology and Physiology - UFRPE, Recife, Brazil.
2 Department of Medicine Veterinary – UFRPE, Recife, Brazil.
3 Department of Anatomical, Sapienza University of Rome, Rome, Italy.
Apresentador: Welma Emidio da Silva
Background: Although the bone has the capacity for self-healing and remodeling throughout adult life, some fractures are too large (critical injuries) to regenerate spontaneously. The use of mesenchymal stem cells (MSCs) has been shown to be a promising option in the bone reconstitution process. Thus, this study aimed to assess the feasibility of using autologous MSCs in the regeneration of critical injuries in rats calvaria. Methods: Eighteen adult male Wistar rats, weighing 285 ± 29g, were used, proceeding from the animal facility of Animal Morphology and Physiology department at UFRPE. The animals were divided into three groups (n = 6): GI - euthanized after 15 days, GII - euthanized after 30 days, GIII - euthanized after 60 days. Two lesions were produced surgically in the animal’s calvaria (right and left). Micro-grafts from MSCs, obtained from xiphoid cartilage and processed in the Rigenera system, were added to the lesions of the left antimere of each animal. The contralateral lesion served as a control in all animals, where saline solution was placed. On the last day of the experimental period of each group, the animals were submitted to computed tomography. After the experimental periods, the animals were euthanized, the calvaria was removed, fixed, decalcified and included in paraffin. The blocks were cut in a microtome (where sections of 5 mm were produced) and the tissue sections were stained with Hematoxylin and Eosin (H.E), for histological analysis and evaluation of the regeneration of the lesions. Results: Bone regeneration of the treated lesions was observed in the three groups. The 15-day group had the best result. The results suggest that CTM grafts promote bone neoformation in a short period of time, constituting a bioactive and biocompatible material. Conclusion: The use of autologous MSC micrografts was efficient in the regeneration of a critical bone defect, created surgically in rat calvaria.
USE OF SELF-ASSEMBLY PEPTIDE HYDROGEL MATRIX IN CARTILAGE TISSUE ENGINEERING
RA Nogoceke1, MA Stimamiglio1, AW Robert11 Instituto Carlos Chagas, Fundação Oswaldo Cruz
Background: Cartilage tissue engineering (CTE) aims to recreate the complex mechanical, biophysical and biological properties of the cartilage tissue found in vivo. The use of three-dimensional self-assembling peptide hydrogels are very attractive for CTE due to their unique properties, such as biocompatibility, and the capacity of creating a highly hydrated microenvironment optimal for three-dimensional cell culture. In the current study we investigate the effects of the self-assembly peptide RADA-16 hydrogel in human mesenchymal stem cell cultures. Methods: To compare 2D to 3D cell culture in the self-assembly peptide hydrogel, Adipose tissue-derived stem cells (ADSCs) were seeded on RADA-16 coating and encapsulated in the RADA-16 hydrogel. The cell cultures were maintained for 4 days and the morphology and proliferative activity were assessed by immunofluorescence stain using anti-vimentin and anti-Ki67 antibodies, respectively. The immunofluorescence analysis was conducted using confocal microscopy and Operetta high content imaging system. Results: The vimentin stained the intermediate filaments of cells, helping to identify the morphology and the distribution of the ADSCs seeded on the RADA-16 coating and in the RADA-16 hydrogels. The cells in the RADA-16 coating showed more spreading and flattened morphology whereas the cells in the hydrogel showed rounded morphology. The analysis of Ki-67 expression suggested that cells proliferate in the RADA-16 scaffolds, but at lower levels compared to monolayer cell culture. Conclusion: The self-assembly peptide RADA-16 hydrogel offered a viable environment for ADSCs to adhere and proliferate. Further analysis is going to be conducted to assess the effects of the RADA-16 hydrogel in the chondrogenic differentiation of ADSCs and its potential in CTE.
