RESUMEN
In vivo experiments are accompanied by ethical issues, including sacrificing a large number of animals as well as large costs. A new in vivo 3D screening system was developed to reduce the number of required animals without compromising the results. The present pilot study examined a multiwell array system in combination with three different collagen-based biomaterials (A, B and C) using subcutaneous implantation for 10 days and histological and histomorphometrical evaluations. The tissue reaction towards the device itself was dominated by mononuclear cells. However, three independent biomaterial-specific tissue reactions were observed in three chambers. The results showed a mononuclear cell-based tissue reaction in one chamber (A) and foreign body reaction by multinucleated giant cells in the other two chambers (B and C). Statistical analysis showed a significantly higher number of multinucleated giant cells in cases B and C than in case A (A vs. B; ***P < 0.001), (A vs. C; P < 0.01). These outcomes were comparable to previously published observations with conventional biomaterial implantation. The present data lead to the conclusion that this 3D screening system could be an alternative tool to enhance the effectiveness of in vivo experiments, thus offering a more economic strategy to screen biomaterial-related cellular reactions, while saving animals, without influencing the final outcome.
Asunto(s)
Materiales Biocompatibles/química , Técnicas de Cultivo de Célula/instrumentación , Colágeno/química , Reacción a Cuerpo Extraño , Animales , Células Gigantes/citología , Sistema Inmunológico , Inflamación , Ratones , Proyectos Piloto , Piel/metabolismo , Porcinos , Ingeniería de Tejidos/métodos , Investigación Biomédica TraslacionalRESUMEN
The biomaterials physicochemical characteristics influence their cellular reaction, degradation and regenerative capacities. Macrophages and multinucleated giant cells (MNGCs) are observed in the augmentation area of biomaterials. This study, for the first time, evaluated the polarization pattern of macrophages and MNGCs in response to two different bone substitute materials (synthetic bone substitute material [SBSM] = NanoBone vs. xenogeneic bone substitute material [XBSM] = Bio-Oss) in human bone biopsies compared to non-augmented bone (control). Histomorphometrical analysis of the polarization in proinflammatory (M1) and anti-inflammatory (M2) cells was performed using different immunohistochemical markers: CD-68 = macrophages; CCR-7 and Cox-2 (M1) and CD-206 and CD-163 (M2) and tartrate-resistant acid phosphatase (TRAP). The macrophage polarization pattern in SBSM showed a significantly higher number of M1 cells than did XBSM and non-augmented bone. XBSM induced a significantly higher number of CD-206-positive macrophages than SBSM did. No significant difference was found between XBSM and the non-augmented bone. MNGCs expressed CD-68 and TRAP. In both test-groups, MNGCs showed a high proinflammatory character (CCR-7 and Cox-2-positive) and their number in the SBSM group was significantly higher than that of XBSM. The tissue distribution showed a significantly low percentage of the remaining biomaterial in SBSM compared to XBSM. Within the limitations of this study, these findings show that MNGCs exhibit a rather proinflammatory character and lead to biomaterial degradation, once they are induced in a high number. The premature degradation of bone substitute materials is compensated with a high percentage of connective tissue and not new bone formation. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 780-790, 2019.
Asunto(s)
Antígenos de Diferenciación/biosíntesis , Materiales Biocompatibles/efectos adversos , Sustitutos de Huesos/efectos adversos , Durapatita/efectos adversos , Reacción a Cuerpo Extraño/metabolismo , Células Gigantes de Cuerpo Extraño/metabolismo , Transducción de Señal , Dióxido de Silicio/efectos adversos , Materiales Biocompatibles/química , Sustitutos de Huesos/química , Combinación de Medicamentos , Durapatita/química , Reacción a Cuerpo Extraño/patología , Regulación de la Expresión Génica , Células Gigantes de Cuerpo Extraño/patología , Humanos , Dióxido de Silicio/químicaRESUMEN
Separating wounded serosa by physical barriers is the only clinically approved adjunct for postoperative adhesion prevention. Since the optimal adhesion barrier has not been found, it is essential to improve our pathogenic understanding of adhesion formation and to compare the effects of different barrier materials on tissue and cells. Wistar rats underwent standardized peritoneal damage and were treated either with Seprafilm, Adept, Intercoat, Spraygel, SupraSeal or remained untreated as a control. 14 days postoperatively, the lesions were explanted and histomorphologically analyzed using the European ISO score to evaluate material implants. Striking differences between the material groups were present regarding the inflammation, fibrosis, and foreign body reaction. According to the ISO score, Intercoat and Spraygel were considered as nonirritating to tissue. Adept, Seprafilm, and SupraSeal were assessed as mild-irritating materials. Interestingly, the most effective material in adhesion prevention revealed moderate inflammation accompanied by minor fibrosis. The degree of inflammation to barrier materials does not predict the efficacy in the prevention of adhesions. Histopathological investigations are crucial to improve our understanding of the cellular mechanisms during adhesion formation and elucidate the tissue response to material approaches used in adhesion prevention. This will lead to improved antiadhesive strategies and the development of functional barrier biomaterials. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 598-609, 2018.
Asunto(s)
Materiales Biocompatibles/farmacología , Ácido Hialurónico/farmacología , Peritoneo/efectos de los fármacos , Complicaciones Posoperatorias/tratamiento farmacológico , Adherencias Tisulares/tratamiento farmacológico , Animales , Femenino , Fibrosis/etiología , Fibrosis/patología , Reacción a Cuerpo Extraño/etiología , Reacción a Cuerpo Extraño/patología , Inflamación/etiología , Inflamación/patología , Membranas Artificiales , Peritoneo/cirugía , Complicaciones Posoperatorias/patología , Complicaciones Posoperatorias/prevención & control , Ratas , Ratas Wistar , Adherencias Tisulares/patología , Adherencias Tisulares/prevención & controlRESUMEN
In the context of prevascularization strategies for tissue-engineering purposes, co-culture systems consisting of outgrowth endothelial cells (OECs) and primary osteoblasts (pOBs) have been established as a promising in vitro tool to study regeneration mechanisms and to identify factors that might positively influence repair processes such as wound healing or angiogenesis. The development of autologous injectable platelet-rich fibrin (PRF), which can be generated from peripheral blood in a minimal invasive procedure, fulfils several requirements for clinically applicable cell-based tissue-engineering strategies. During this study, the established co-culture system of OECs and pOBs was mixed with injectable PRF and was cultivated in vitro for 24 h or 7 days. The aim of this study was to analyse whether PRF might have a positive effect on wound healing processes and angiogenic activation of OECs in the co-culture with regard to proinflammatory factors, adhesion molecules and proangiogenic growth factor expression. Histological cell detection revealed the formation of lumina and microvessel-like structures in the PRF/co-culture complexes after 7 days of complex cultivation. Interestingly, the angiogenic activation of OECs was accompanied by an upregulation of wound healing-associated factors, as well as by a higher expression of the proangiogenic factor vascular endothelial growth factor, which was evaluated both on the mRNA level as well as on the protein level. Thus, PRF might positively influence wound healing processes, in particular angiogenesis, in the in vitro co-culture, making autologous PRF-based matrices a beneficial therapeutic tool for tissue-engineering purposes by simply profiting from the PRF, which contains blood plasma, platelets and leukocytes.
Asunto(s)
Huesos/irrigación sanguínea , Técnicas de Cocultivo/métodos , Modelos Biológicos , Neovascularización Fisiológica , Fibrina Rica en Plaquetas/metabolismo , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Proteína Morfogenética Ósea 2/genética , Proteína Morfogenética Ósea 2/metabolismo , Diferenciación Celular , Células Cultivadas , Células Endoteliales/citología , Femenino , Regulación de la Expresión Génica , Humanos , Inyecciones , Masculino , Microvasos/fisiología , Osteoblastos/citología , Osteogénesis , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Cicatrización de HeridasRESUMEN
Biomaterials are widely used in guided bone regeneration (GBR) and guided tissue regeneration (GTR). After application, there is an interaction between the host immune system and the implanted biomaterial, leading to a biomaterial-specific cellular reaction. The present review focuses on cellular reactions to numerous biomaterials in vivo with consideration of different implantation models and microenvironments in different species, such as subcutaneous implantation in mice and rats, a muscle model in goats and a femur model in rabbits. Additionally, cellular reactions to different biomaterials in various clinical indications within the oro-maxillofacial surgical field were considered. Two types of cellular reactions were observed. There was a physiological reaction with the induction of only mononuclear cells and a pathological reaction with the induction of multinucleated giant cells (MNGCs). Attention was directed to the frequently observed MNGCs and consequences of their appearance within the implantation region. MNGCs have different subtypes. Therefore, the present review addresses the different morphological phenotypes observed within the biomaterial implantation bed and discusses the critical role of MNGCs, their subtypes and their precursors as well as comparing the characteristics and differences between biomaterial-related MNGCs and osteoclasts. Polymeric biomaterials that only induced mononuclear cells underwent integration and maintained their integrity, while polymeric biomaterials that induced MNGCs underwent disintegration with material breakdown and loss of integrity. Hence, there is a question regarding whether our attention should be directed to alternative biological concepts, in combination with biomaterials that induce a physiological mononuclear cellular reaction to optimize biomaterial-based tissue regeneration.
Asunto(s)
Materiales Biocompatibles/metabolismo , Células Gigantes/inmunología , Regeneración Tisular Dirigida , Inmunidad Celular , Ortodoncia , Animales , Regeneración Ósea , Microambiente Celular , Humanos , Sistema Mononuclear FagocíticoRESUMEN
The histological and ultrastructural findings of rib specimens after two re-interventions in the case of recurrence of pectus carinatum (PC) are presented in this report. A 15-year-old boy developed recurrences of mild PC after re-chondroplasties using the Ravitch technique. Histological study of the resected cartilage showed markedly degenerative changes of the sternocostal cartilage. For the first time, intracellular crystalline inclusions in some of the chondrocytes were found. These findings indicate metabolic changes as a possible pathogenetic parameter in PC.
Asunto(s)
Enfermedades del Desarrollo Óseo/patología , Esternón/anomalías , Adolescente , Enfermedades del Desarrollo Óseo/metabolismo , Enfermedades del Desarrollo Óseo/cirugía , Cartílago Articular/metabolismo , Cartílago Articular/ultraestructura , Condrocitos/metabolismo , Condrocitos/ultraestructura , Cristalización , Humanos , Cuerpos de Inclusión/metabolismo , Cuerpos de Inclusión/ultraestructura , Masculino , Microscopía Electrónica , Recurrencia , Esternón/cirugía , Esternón/ultraestructuraRESUMEN
Formic acid (FA) plays a key role in the preparation of silk fibroin (SF) scaffolds from cocoons of Bombyx mori and is used for fibre distribution. In this study, we used a subcutaneous implantation model in Wistar rats to examine SF scaffolds prepared by treating the degummed cocoon with FA for either 30 or 60 min. The tissue reaction and inflammatory response to SF was assessed by qualitative histology at intervals from 3 to 180 days. Additionally, dynamic biomaterial-induced vascularization and biomaterial degradation were quantified using a technique for analysing an image of the entire implanted biomaterial. Varying the FA treatment time led to different scaffold morphologies and resulted in two distinct peri-implant tissue reactions. The 30 min-treated scaffold was integrated into the surrounding tissue beginning at day 3 after implantation and vascularization increased 10-fold from 15 to 180 days, while the scaffold was continuously degraded throughout the first 90 days. In contrast, the 60 min-treated SF scaffold appeared as bulk for the first 90 days after implantation, after which a rapid degradation and vascularization process began. After 180 days, the tissue response was similar for both scaffolds, with eventual formation of a well vascularized connective tissue integrating the SF fibres. This study indicates that by modifying the FA treatment time, the tissue reaction to SF scaffolds can be tailored for different tissue-engineering applications. The tunability and biocompatibility of SF make it an attractive scaffold for exploration in regenerative medicine and clinical tissue engineering.
Asunto(s)
Fibroínas/química , Formiatos/farmacología , Regeneración/efectos de los fármacos , Regeneración/fisiología , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Animales , Microscopía Electrónica de Rastreo , Neovascularización Fisiológica/efectos de los fármacos , Ratas , Ratas Wistar , Medicina Regenerativa , Coloración y Etiquetado , Factores de TiempoRESUMEN
Prostaglandin E(2) (PGE(2)) is involved in angiogenesis, bone repair and cartilage metabolism. Thus, PGE(2) might represent a suitable signaling molecule in different tissue engineering applications. PGE(2) also has a short half-life time. Its incorporation into poly-D: ,L: -lactide-co-glycolide (PLGA) microspheres was demonstrated in a previous study. However, the stability of bioactive PGE(2) in these microspheres is unknown. With an adjusted mass spectrometry assay we investigated the amount of incorporated PGE(2) and the stability of PGE(2) in conventional cell culture medium and in PLGA microspheres. The stability of PGE(2) was closely pH dependent. Strong acidic or basic environments reduced the half-life from 300 h (pH 2.6-4.0) to below 50 h at pH 2.0 or pH 8.8. The half-life of PGE(2) incorporated into poly-D: ,L: -lactide-co-glycolide increased drastically to 70 days at 37 degrees C and to 300 days at 8 degrees C. Analysis with scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated a distinct nanostructure of the polymeric phase and both nano- and microporosity.
Asunto(s)
Dinoprostona/química , Ácido Láctico/química , Microesferas , Ácido Poliglicólico/química , Polímeros/química , Ingeniería de Tejidos/métodos , Cromatografía Liquida , Portadores de Fármacos/química , Estabilidad de Medicamentos , Cromatografía de Gases y Espectrometría de Masas , Semivida , Espectrometría de Masas , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Nanopartículas/química , Nanopartículas/ultraestructura , Tamaño de la Partícula , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Porosidad , Temperatura , Agua/químicaRESUMEN
BACKGROUND: Patients treated with bisphosphonates because of bone metastases have been shown to develop osteonecrosis of the jaws. In the present study, we examined the histologic findings of these cases. As similarities between this disorder and infected osteoradionecrosis (IORN) are described, both lesions were compared. METHODS: We investigated eight patients with bisphosphonate treatment and osteonecrosis (four female, four male; median age: 65.6 years; cancer: multiple myeloma in five patients, breast cancer in three patients; mandibular involvement in five patients, maxillar involvement in three cases), and 10 patients suffering from IORN (all male; median age: 61.3 years; cancer: squamous cell carcinoma in nine patients, adenoid cystic carcinoma in one patient; mandibular involvement in all cases). Multicentric and bilateral involvement was common in the bisphosphonate group. Histologically, the bone revealed diffuse and patchy areas of necrosis in the bisphosphonate group, while in IORN osteonecrosis was larger and not diffusely distributed. RESULTS: In all cases, we found Actinomyces attached to the necrotic bone tissue. In five of eight bisphosphonates cases, and in six of 10 IORN cases, numerous osteoclasts could be detected close to vital bone exhibiting signs of bone resorption. Pseudoepitheliomatous hyperplasia (PH) was revealed in five of eight bisphosphonate patients, and in seven of 10 IORN patients. CONCLUSION: We conclude that Actinomyces is involved in the chronic, non-healing inflammatory processes as a characteristic feature of both diseases. Together with the associated presence of increased osteoclast numbers, we suggest that both factors may be involved in osteolytic mechanisms.
Asunto(s)
Neoplasias Óseas/tratamiento farmacológico , Difosfonatos/efectos adversos , Enfermedades Maxilomandibulares/patología , Osteonecrosis/patología , Osteorradionecrosis/patología , Actinomyces/aislamiento & purificación , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/efectos adversos , Conservadores de la Densidad Ósea/efectos adversos , Neoplasias Óseas/secundario , Carcinoma Adenoide Quístico/tratamiento farmacológico , Carcinoma Adenoide Quístico/secundario , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/secundario , Femenino , Humanos , Enfermedades Maxilomandibulares/inducido químicamente , Enfermedades Maxilomandibulares/microbiología , Masculino , Persona de Mediana Edad , Osteonecrosis/inducido químicamente , Osteonecrosis/microbiología , Osteorradionecrosis/microbiologíaRESUMEN
We have examined a novel biomaterial consisting of a non-woven fibroin net produced from silk (Bombyx mori) cocoons for its ability to support the growth of human cells. Various human cells of different tissue and cell types (endothelial, epithelial, fibroblast, glial, keratinocyte, osteoblast) were examined for adherence and growth on the nets by confocal laser microscopy after staining of the cells with calcein-AM and by electron microscopy. All the cells readily adhered and spread over the individual fibers of the nets. Most of the cells were able to grow and survive on the nets for at least 7 weeks and growth not only covered the individual fibers of the net but generally bridged the gaps between individual fibers forming tissue-like structures. Scanning electron microscopic examination of the nets demonstrated a tight association of individual cells with the fibers and nets examined after removal of cells showed no evidence that the growth of cells in any way changed the structure of the fibers. Thus, silk fibroin nets are highly human cell-compatible and should be a useful new scaffolding biomaterial applicable for a wide range of target tissues in addition to supporting endothelial cells required for the vascularization of the newly formed tissue.