• Journal of the korean academy of Pediatric Dentistry
• /
• v.40 no.3
• /
• pp.216-222
• /
• 2013

Paradigm shift in management of infected immature permanent teeth has occurred. The new concept of the treatment includes minimal or no intracanal instrumentation, disinfection with triple antibiotic paste and sealing with mineral trioxide aggregate. This regenerative endodontic treatment promotes differentiation of periradicular stem cells that induce regeneration of vital tissue and continuation of root formation. Thorough disinfection and three-dimensional scaffold are important in this new concept of the treatment. Platelet-rich fibrin has been reported as 'new scaffold' instead of blood clot, which had been used in the past. Triple antibiotics can be used to disinfect the tooth but may lead to complications including discoloration. Three cases of infected immature permanent tooth caused by dens evaginatus fracture are presented. After removal of necrotic pulp and thorough intracanal irrigation, only platelet-rich fibrin was applied to the root canal in the first case. In the other cases, topical antibiotics was used for disinfection and platelet-rich fibrin for scaffold. In all the cases, the opening was sealed with mineral trioxide aggregate. All the cases showed proper healing of inrabony lesion and some lengthening of root. According to these cases, regenerating vital tissue of the infected immature permanent tooth can be achieved with disinfection and application of platelet-rich fibrin.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.31 no.3
• /
• pp.198-206
• /
• 2009

Purpose: The aims of this study were to assess the in vitro co-culturing pattern of isolated skin-derived precursor cells (SKPs) with a mixed demineralized bone (DMB) and fibrin glue scaffold and to evaluate in vivo osteogenesis after transplantation of autogenous SKPs with a these mixed scaffold in the animal's mandibular defects. Materials and Methods: We isolated SKPs from the ears of adult 4 miniature pigs. The isolated SKPs were co-cultured with a mixed DMB and fibrin glue scaffold in a non-osteogenic medium for 1, 2, and 4 weeks. Histological characteristics of in vitro co-cultured cells and scaffold were evaluated. $1{\times}10^7\;cells/100\;{\mu}l$ of autogenous porcine SKPs were grafted into the mandibular defects with a DMB and fibrin glue scaffold. In the control sites, only a scaffold was grafted, without SKPs. After two animals each were euthanized at 2 and 4 weeks after grafting, the in vivo osteogenesis was evaluated with histolomorphometric and osteocalcin immunohistochemical studies. Results: Homogeneously shaped skin-derived cells were isolated from porcine ear skin after 3 or 4 weeks of primary culture. In vitro osteogenic differentiation of SKPs was observed after co-culturing with a DMB and fibrin glue scaffold in a non-osteogenic medium. Von Kossa-positive bone minerals were also noted in the co-cultured medium at 4 weeks. As the culture time progressed, the number of observable cells increased. Trabecular new bone formation and osteocalcin expression were more pronounced in the SKP-grafted group compared to the control group. Conclusion: These findings suggest that autogenous SKP grafting with a DMB and fibrin glue scaffold can serve as a useful alternative to bone grafting technique.

• Clinical and Experimental Reproductive Medicine
• /
• v.49 no.4
• /
• pp.259-269
• /
• 2022

Objective: Animal-free scaffolds have emerged as a potential foundation for consistent, chemically defined, and low-cost materials. Because of its good potential for high biocompatibility with reproductive tissues and well-characterized scaffold design, we investigated whether polyglycolic acid (PGA) could be used as an animal-free scaffold instead of natural fibrin-agarose, which has been used successfully for three-dimensional human endometrial cell culture. Methods: Isolated primary endometrial cells was cultured on fibrin-agarose and PGA polymers and evaluated various design parameters, such as scaffold porosity and mean fiber diameter. Cytotoxicity, scanning electron microscopy (SEM), and immunostaining experiments were conducted to examine cell activity on fabricated scaffolds. Results: The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and SEM results showed that endometrial cells grew and proliferated on both scaffolds. Immunostaining showed cytokeratin and vimentin expression in seeded cells after 7 days of culture. On both scaffolds, an epithelial arrangement of cultured cells was found on the top layer and stromal arrangement matrix on the bottom layer of the scaffolds. Therefore, fibrin-agarose and PGA scaffolds successfully mimicked the human endometrium in a way suitable for in vitro analysis. Conclusion: Both fibrin-agarose and PGA scaffolds could be used to simulate endometrial structures. However, because of environmental and ethical concerns and the low cost of synthetic polymers, we recommend using PGA as a synthetic polymer for scaffolding in research instead of natural biomaterials.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.39 no.2
• /
• pp.174-180
• /
• 2012

In case of an immature tooth with necrotic pulp, regeneration of pulp tissue into a canal would be the ideal outcome. It may be capable of promoting the continuation of normal root development. Platelet-rich fibrin has been suggested as a potentially ideal scaffold for regenerative endodontic treatment. Immature permanent teeth of young children were diagnosed with pulp necrosis and apical abscess as the result of clinical and radiographic examination. After removal of necrotic pulp, canal was irrigated with 5.25% NaOCl and dried with paper point. A triple antibiotic mixture was placed in canal space in 3 weeks. After removal of the antibiotic mixture, the platelet-rich fibrin was injected into the canal space with MTA placed directly over the platelet-rich fibrin clot. The coronal region was restored by composite resin. On the basis of short-term results of the present 3 cases, regeneration of vital tissues appears to be possible in a tooth with necrotic pulp and a periapical lesion. Also, platelet-rich fibrin proves to be potentially an ideal scaffold for this procedure. Therefore, long-term clinical observation and examination about this treatment using platelet-rich fibrin in immature permanent teeth of young children are considered to be necessary.

• Polymer(Korea)
• /
• v.37 no.2
• /
• pp.141-147
• /
• 2013

Poly(lactide-co-glycolic acid) (PLGA) has been widely used in the drug delivery and tissue engineering applications because of its good mechanical strength and biodegradation profile. However, cell attachment to the scaffold is low compared with that on fibrin although cells can be attached to the polymer surface. In this study, PLGA scaffolds were soaked in cells-fibrin suspension and polymerized with dropping fibrinogen-thrombin solution. Cellular proliferation activity was observed in PLGA/fibrin-seeded costal cartilage cells (CC) on 1, 3, and 7 days using the MTT assay and SEM. The effects of fibrin on the extracellular matrix (ECM) formation were evaluated using CC cell-seeded PLGA/fibrin scaffolds. The PLGA/fibrin scaffolds elicited more production of glycosaminoglycan (GAG) and collagen than the PLGA scaffold. In this study, fibrin incorporated PLGA scaffolds were prepared to evaluate the effects of fibrin on the cell attachment and proliferation in vitro and in vivo. In this result, we confirmed that proliferation of cells in PLGA/fibrin scaffolds were better than in PLGA scaffolds. The PLGA/fibrin scaffolds provide suitable environment for growth and proliferation of costal cartilage cells.

• Polymer(Korea)
• /
• v.34 no.1
• /
• pp.63-68
• /
• 2010

In this study, we evaluated the effect of fibrin, a natural material, on the local inflammatory reaction of PLGA in vivo. PLGA degradation products can decrease the pH in the surrounding tissue, causing local inflammatory reaction. To solve this problem, fibrin/PLGA scaffolds were implanted in 5-week-old Wister rats. To evaluate the influence of fibrin content on inflammatory cytokine expression induced by PLGA, RT-PCR analysis was used. Fibrous wall thickness and macrophage infiltration were evaluated by H&E and ED-1 immunohistochemical staining, respectively. In this study, we showed that fibrin/PLGA scaffolds reduced inflammatory reaction as compared to PLGA scaffold. We concluded that fibrin could reduce inflammatory response of PLGA.

• Journal of the Korean Society of Radiology
• /
• v.16 no.6
• /
• pp.799-805
• /
• 2022

Radiation therapy of human tissues, including bone tissue, is accompanied by side effects on normal tissues. It has a more lethal effect on stem cells, which play an essential role in tissue regeneration, including the basal cells constituting the tissue. In this study, the mouse parietal model, which implemented an artificial osteoradionecrosis model on the parietal region of the mouse, was artificially defected and then the bone regeneration was tested. In order to overcome the implemented osteoradionecrosis, a fibrin scaffold, widely used as a biomaterial, and stromal cell-derived factor-1 (SDF-1), which is used as a long-term treatment for damaged, were mixed to verify the osteoradionecrosis regeneration effect on the parietal of mouse. In order to expect a synergistic effect in the fibrin scaffolds, a fibrin scaffolds was prepared after maintaining the concentration of SDF-1 (1 ㎍/ml) in the fibrinogen solution. In this study, after artificially creating a osteoradionecrosis model in the parietal region of mouse, fibrin scaffolds were incorporated to analyze the effect of bone regeneration within 4 weeks, the initial stage of bone regeneration. In conclusion, the combined use of these two substances did not show a dramatic regenerative effect in inducing the regeneration of osteoradionecrosis in the parietal region of mouse. However, positive results were obtained that can be maintain the bone regeneration effect environment at the initial stage. Therefore, the combined use of the fibrin scaffold and SDF-1 is considered to be a suitable candidate for the effect of overcoming osteoradionecrosis.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.30 no.4
• /
• pp.323-332
• /
• 2008

Aim of the study: Scaffolds are crucial to tissue engineering/regeneration. Biodegradable polymer/ceramic composite scaffolds can overcome the limitations of conventional ceramic bone substitutes such as brittleness and difficulty in shaping. In this study, poly(L-lactide)/hydroxyapatite(PLLA/HA) composite scaffolds were fabricated for in vivo bone tissue engineering. Material & methods: In this study, PLLA/HA composite microspheres were prepared by double emulsion-solvent evaporation method, and were evaluated in vivo bone tissue engineering. Bone marrow mesenchymal stem cell from rat iliac crest was differentiated to osteoblast by adding osteogenic medium, and was mixed with PLLA/HA composite scaffold in fibrin gel and was injected immediately into rat cranial bone critical size defect(CSD:8mm in diameter). At 1. 2, 4, 8 weeks after implantation, histological analysis by H-E staining, histomorphometric analysis and radiolographic analysis were done. Results: BMP-2 loaded PLLA/HA composite scaffolds in fibrin gel delivered with osteoblasts differentiated from bone marrow mesenchymal stem cells showed rapid and much more bone regeneration in rat cranial bone defects than control group. Conclusion: This results suggest the feasibility and usefulness of this type of scaffold in bone tissue engineering.

• Restorative Dentistry and Endodontics
• /
• v.39 no.1
• /
• pp.1-6
• /
• 2014

Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF) has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.2
• /
• pp.87-93
• /
• 2010

Introduction: In our previous studies, we isolated porcine skin-derived mesenchymal stem cells (pSDMSCs) from the ears of adult miniature pigs and evaluated the pluripotency of these pSDMSCs based on expressions of transcription factors, such as Oct-4, Sox-2, and Nanog. Moreover, the characteristic of mesenchymal stem cells was revealed by the expression of various mesenchymal stem cell markers, including CD29, CD44, CD90, and vimentin. The aim of this study was to evaluate in vivo osteogenesis after maxillary sinus lift procedures with autogenous pSDMSCs and scaffold. Materials and Methods: The autogenous pSDMSCs were isolated from the 4 miniature pigs, and cultured to 3rd passage with same methods of our previous studies. After cell membranes were labeled using a PKH26, $1{\times}10^{7}$ cells/$100{\mu}L$ of autogenous pSDMSCs were grafted into the maxillary sinus with a demineralized bone matrix (DBM) and fibrin glue scaffold. In the contralateral control side, only a scaffold was grafted, without SDMSCs. After two animals each were euthanized at 2 and 4 weeks after grafting, the in vivo osteogenesis was evaluated with histolomorphometric and osteocalcin immunohistochemical studies. Results: In vivo PKH26 expression was detected in all specimens at 2 and 4 weeks after grafting. Trabecular bone formation and osteocalcin expression were more pronounced around the grafted materials in the autogenous pSDMSCs-grafted group compared to the control group. Newly generated bone was observed growing from the periphery to the center of the grafted material. Conclusion: The results of the present study suggest that autogenous skin-derived mesenchymal stem cells grafting with a DBM and fibrin glue scaffold can be a predictable method in the maxillary sinus floor elevation technique for implant surgery.