Effects of chemical and physical methods on decellularization of murine skeletal muscles.

Volumetric muscle loss causes functional weakness and is often treated with muscle grafts or implant of biomaterials. Extracellular matrices, obtained through tissue decellularization, have been widely used as biological biomaterials in tissue engineering. Optimal decellularization method varies among tissues and have significant impact on the quality of the matrix. This study aimed at comparing the efficacy of four protocols, that varied according to the temperature of tissue storage and the sequence of chemical reagents, to decellularize murine skeletal muscles. Tibialis anterior muscles were harvested from rats and were frozen at -20°C or stored at room temperature, followed by decellularization in solutions containing EDTA + Tris, SDS and Triton X-100, applied in different sequences. Samples were analyzed for macroscopic aspects, cell removal, decrease of DNA content, preservation of proteins and three-dimensional structure of the matrices. Processing protocols that started with incubation in SDS solution optimized removal of cells and DNA content and preserved the matrix ultrastructure and composition, compared to those that were initiated with EDTA + Tris. Freezing the samples before decellularization favored cell removal, regardless of the sequence of chemical reagents. Thus, to freeze skeletal muscles and to start decellularization with 1% SDS solution showed the best results.

Restoring Facial Contour and Harmony Using Biphasic Calcium Phosphate Bioceramics.

BACKGROUND: The restoration of facial contour is one of the pillars for the treatment of facial disharmonies and deformities. Fat transplantation and fillers have been widely used to improve the positioning of soft tissues, which are, however, directly related to the conditions and positioning of the underlying bone tissue. Recontouring of the latter has been performed using osteotomies and several types of bone grafts or biomaterials, as inlay or onlay grafts/implants. Here, biphasic calcium phosphate bioceramics were applied in a series of cases, their long-term results are shown, and their advantages, discussed. METHODS: A retrospective analysis of 20 patients, who were subjected to facial recontour with onlay implants of biphasic calcium phosphate bioceramics, is reported. Patients were seeking to improve facial harmony due to congenital deformities, trauma, tumor resection or signs of aging, and were followed for up to 16 years. Clinical data, radiographic images, and information regarding pain and other findings were retrieved from medical records. RESULTS: Six patients were men and 14 were women. Their ages ranged from 19 to 64 years. Bioceramics were implanted under the periosteum through external or intraoral incisions. Some patients underwent combined procedures, such as rhinoplasties or facial lifting. None of the patients presented exacerbated inflammation or pain. One of them had infection in the intraoral incision, which was resolved with medication. CONCLUSION: All patients had improved facial contours following the use of bio-ceramics to augment bone tissue and presented stable results at long-term evaluation.

Comparison between placental and skeletal muscle ECM: in vivo implantation.

PURPOSE OF THE STUDY: Several tissues have been decellularized and their extracellular matrices used as allogeneic or xenogeneic scaffolds, either in orthotopic or heterotopic implantations, for tissue engineering purposes. Placentas have abundant matrix, extensive microvascular structure, immunomodulatory properties, growth factors and are discarded after birth, representing an interesting source of extracellular matrix. This study aimed at comparing decellularized canine placentas and murine skeletal muscles to regenerate skeletal muscles in a rat model. MATERIALS AND METHODS: Muscle pockets were created at the posterior limbs of male Wistar rats, where the muscle- and placenta-derived extracellular matrices were implanted. Macroscopic, histological, and immunohistochemical analyses were performed after 3, 15, and 45 days of surgeries. RESULTS: On the third day, intense inflammatory reaction, with macrophages (CD163+) and proliferative cells (PCNA+) being observed in control group and adjacent to the decellularized matrices. The percentage of proliferative cells was higher in placenta than in muscle matrices. Macrophages CD163+ high were higher in muscles than in placentas, whereas CD163+ low were higher in placentas than in muscle ECM, at days 3 and 15. Placental matrices were not completely degraded at day 15, as opposed to the muscular ones. After 45 days, both matrices were resorbed and morphologically normal myofibers, with reduction of cell infiltration, were observed. CONCLUSIONS: These results demonstrated that xenogeneic placental ECM, implanted heterotopically (representing a biologically critical and challenging microenvironment), induced local inflammatory reactions similar to the allogeneic muscle ECM, implanted orthotopically. Thus, placenta-derived extracellular matrix must be further explored in regenerative medicine.

Comparison between placental and skeletal muscle ECM: in vivo implantation

Purpose of the study: Several tissues have been decellularized and their extracellular matrices used as allogeneic or xenogeneic scaffolds, either in orthotopic or heterotopic implantations, for tissue engineering purposes. Placentas have abundant matrix, extensive microvascular structure, immunomodulatory properties, growth factors and are discarded after birth, representing an interesting source of extracellular matrix. This study aimed at comparing decellularized canine placentas and murine skeletal muscles to regenerate skeletal muscles in a rat model. Materials and Methods: Muscle pockets were created at the posterior limbs of male Wistar rats, where the muscle- and placenta-derived extracellular matrices were implanted. Macroscopic, histological, and immunohistochemical analyses were performed after 3, 15, and 45 days of surgeries. Results: On the third day, intense inflammatory reaction, with macrophages (CD163+) and proliferative cells (PCNA+) being observed in control group and adjacent to the decellularized matrices. The percentage of proliferative cells was higher in placenta than in muscle matrices. Macrophages CD163+ high were higher in muscles than in placentas, whereas CD163+ low were higher in placentas than in muscle ECM, at days 3 and 15. Placental matrices were not completely degraded at day 15, as opposed to the muscular ones. After 45 days, both matrices were resorbed and morphologically normal myofibers, with reduction of cell infiltration, were observed. Conclusions: These results demonstrated that xenogeneic placental ECM, implanted heterotopically (representing a biologically critical and challenging microenvironment), induced local inflammatory reactions similar to the allogeneic muscle ECM, implanted orthotopically. Thus, placenta-derived extracellular matrix must be further explored in regenerative medicine.

Isolation and characterization of canine perivascular stem/stromal cells for bone tissue engineering.

For over 15 years, human subcutaneous adipose tissue has been recognized as a rich source of tissue resident mesenchymal stem/stromal cells (MSC). The isolation of perivascular progenitor cells from human adipose tissue by a cell sorting strategy was first published in 2008. Since this time, the interest in using pericytes and related perivascular stem/stromal cell (PSC) populations for tissue engineering has significantly increased. Here, we describe a set of experiments identifying, isolating and characterizing PSC from canine tissue (N = 12 canine adipose tissue samples). Results showed that the same antibodies used for human PSC identification and isolation are cross-reactive with canine tissue (CD45, CD146, CD34). Like their human correlate, canine PSC demonstrate characteristics of MSC including cell surface marker expression, colony forming unit-fibroblast (CFU-F) inclusion, and osteogenic differentiation potential. As well, canine PSC respond to osteoinductive signals in a similar fashion as do human PSC, such as the secreted differentiation factor NEL-Like Molecule-1 (NELL-1). Nevertheless, important differences exist between human and canine PSC, including differences in baseline osteogenic potential. In summary, canine PSC represent a multipotent mesenchymogenic cell source for future translational efforts in tissue engineering.

The Placenta as an Organ and a Source of Stem Cells and Extracellular Matrix: A Review.

The placenta is a temporal, dynamic and diverse organ with important immunological features that facilitate embryonic and fetal development and survival, notwithstanding the fact that several aspects of its formation and function closely resemble tumor progression. Placentation in mammals is commonly used to characterize the evolution of species, including insights into human evolution. Although most placentas are discarded after birth, they are a high-yield source for the isolation of stem/progenitor cells and are rich in extracellular matrix (ECM), representing an important resource for regenerative medicine purposes. Interactions among cells, ECM and bioactive molecules regulate tissue and organ generation and comprise the foundation of tissue engineering. In the present article, differences among several mammalian species regarding the placental types and classifications, phenotypes and potency of placenta-derived stem/progenitor cells, placental ECM components and current placental ECM applications were reviewed to highlight their potential clinical and biomedical relevance.

Response of stem cells from different origins to biphasic calcium phosphate bioceramics.

Biphasic calcium phosphate (BCP) bioceramics have been successfully applied in a broad variety of presentation forms and with different ratios of hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP). BCPs have been loaded with stem cells from different origins for bone tissue engineering purposes, but evidence of stem cell behavior on different compositions (various HA/ß-TCP ratios) and physical features of BCPs is limited. We compared the adhesion, proliferation, viability and osteogenic potential of human mesenchymal stem cells (MSCs) on granular BCPs with equal HA/ß-TCP ratio of diverse particle sizes and on porous blocks which had different chemical compositions. In addition, the osteogenic differentiation of MSCs was compared to adipose-derived (ADSC) and dental pulp (DPSC) stem cells, as well as to pre-osteoblasts on a particulate BCP. MSCs growing on granular BCPs demonstrated increased number as compared to MSCs growing on blocks. Cells proliferated to a greater extent on small granular BCPs, while large granular BCPs and blocks promoted cell differentiation. Surprisingly, the expression of genes involved in osteogenesis was upregulated in MSCs on bioceramics in basal medium which indicates that BCPs may have osteoinductive potential. This was confirmed with the upregulation of osteochondrogenic markers, at different time points, when stem cells from various tissues were grown on the BCP. This study demonstrates that BCPs, depending on their physical features and chemical composition, modulate stem cell behavior, and that stem cells from different origins are inherently distinct in their gene expression profile and can be triggered toward osteochondrogenic fate by BCPs.

Biphasic calcium phosphate bioceramics for orthopaedic reconstructions: clinical outcomes.

BCP are considered the most promising biomaterials for bone reconstruction. This study aims at analyzing the outcomes of patients who received BCP as bone substitutes in orthopaedic surgeries. Sixty-six patients were categorized according to the etiology and morphology of the bone defects and received scores after clinical and radiographic evaluations. The final results corresponded to the combination of both parameters and varied from 5 (excellent result) to 2 or lower (poor result). Most of the patients who presented cavitary defects or bone losses due to prosthesis placement or revision, osteotomies, or arthrodesis showed good results, and some of them excellent results. However, patients with segmental defects equal or larger than 3 cm in length were classified as moderate results. This study established clinical parameters where the BCP alone can successfully support the osteogenic process and where the association with other tissue engineering strategies may be considered.

Quantification of bone mass gain in response to the application of biphasic bioceramics and platelet concentrate in critical-size bone defects.

Biphasic bioceramics have been widely indicated for bone reconstruction; however, the real gain in bone mass due to the presence of such biomaterials has not been established yet nor the advantages of its association with platelet concentrate. This study aims at quantifying the volume of bone matrix, osteoblasts, osteocytes, blood vessels and adipose tissue after the application of a biphasic bioceramics composed of 65% hydroxyapatite and 35% beta-tricalcium phosphate. Critical-size bone defects were produced in rabbit femora and reconstructed with bioceramics only, with bioceramics combined with platelet concentrate, with platelet concentrate alone, and with no treatment (blood clot). The quantitative evaluation was performed on histological sections using histomorphometry. Our data provide original evidence that consolidates the indication of bioceramics for clinical bone loss reconstruction. The application of biphasic bioceramics alone led to major bone mass gain and was followed by its association with platelet concentrate. On the other hand, platelet concentrate can contribute to the augmentation and maintenance of the adipose tissue, representing a new field for future applications in plastic surgery.

Estudio comparativo del análisis de la estética facial en cirugía ortognática / A comparative study of facial aesthetic analysis in orthognatic surgery

Los autores realizan un estudio comparativo entre procedimientos de diagnóstico estéticos que fueron realizados en los pacientes sometidos a cirugía ortognática, en el Centro Médico Nacional ®20 de Noviembre¼ del ISSSTE, en el periodo comprendido entre enero de 1993 a junio de 1997. En un grupo de pacientes se realizó el diagnóstico de manera convencional y al otro grupo se le anexó el análisis de la estética facial proporcional, obteniendo diferencias en la profundidad del diagnóstico y como resultado, la necesidad de incrementar procedimientos estéticos faciales en los pacientes con deformidades dentofaciales

Incidência e tratamento de fraturas do côndilo da mandíbula no Serviço de Cirurgia e Traumatologia Bucomaxilofacial da Faculdade de Odontologia de Bauru da Universidade de Säo Paulo e Associaçäo Hospitalar de Bauru, no período de 1991 a 1995 / Incidence and tratment of condilar fractures in the bucomaxillofacial surgery and traumatology service of the Bauru Dental School - USP and Bauru Hospitalar Association, in the period of 1991 to 1995

Pela alta incidência de traumas faciais, escassez de trabalhos nacionais publicados e, diversidade de tratamentos instituídos para as fraturas do côndilo da mandíbula, fez-se levantamento estatístico de 4792 pacientes atendidos no Serviço de Cirurgia e Traumatologia Bucomaxilofacial da Faculdade de Odontologia de Bauru da Universidade de Säo Paulo e Associaçäo Hospitalar de Bauru, no período de 1991 a 1995. Deu-se ênfase às fraturas do côndilo mandibular, que foram analisadas sob vários aspectos e estudadas estatisticamente. Resultados permitiram concluir que, o número de pacientes portadores de fraturas faciais e condilares atendidos na cidade de Bauru, durante 05 anos, somam 1492 e 113 respectivamente; os homens na segunda e terceira décadas de vida säo os mais atingidos; as fraturas isoladas e as unilaterais säo as mais frequentes; as quedas acidentais constituem a etiologia mais comum; o tratamento cirúrgico fechado é o mais utilizado, sendo a prevençäo de fundamental importância

Clinical evaluation of novocol anesthesic efficiency

This research had as main objectives evaluate NOVOCOL anaesthesic efficiency in odontological surgical proceedings and the occurrence of adverse reactions decurrent from its utilization. A total of 150 patients were included in the research, having the evaluation the following patterns: patient's age, his emotional condition before surgery, pre-anaesthesic medication, blood pressure, king of surgery, anaesthesic technique, time of induction and duration, anaesthesic volume and, finally, patient's opinion about anaesthesic efficiency. Results showed that NOVOCOL was efficient in most of surgical proceedings (74,5%), induction time is satisfactory and duration time is sufficient to surgical manouvres. It wasn't observed efficiency in patients who had taken pre-anaesthesic medication and a better effect in calm or normotense ones. No adverse reaction was found in the patients who were tested. It was concluded that NOVOCOL fits into necessary patterns to the realization of surgical manouevres reported here as a safe and efficient anaesthesic

Avaliação clínica da eficácia do anestésico NOVOCOL / Clinical evaluation of NOVOCOL anesthetic solution

Este trabalho teve como objetivo avaliar a eficácia do anestésico NOVOCOL em manobras cirúrgicas odontológicas, assim como a ocorrência de reações adversas recorrentes da sua utilização. Foram incluídos na pesquisa 150 pacientes, sendo que a avaliação seguiu os seguintes padrões: idade do paciente, seu estado emocional antes da anestesia, medicação pré-anestésica, pressão arterial, tipo de cirurgia, técnica anestésica, tempos de indução e duração, volume anestésico e finalmente, a opinião do paciente sobre a eficácia do anestésico. Os resultados mostraram que o NOVOCOL foi eficiente na maioria dos procedimentos cirúrgicos (74,5 por cento), o tempo de indução é satisfatório, e o tempo de duração é suficiente para realização das manobras cirúrgicas. Não se observou aumento da eficácia em pacientes que receberam medicação pré-anestésica, nem um melhor efeito em pacientes calmos ou normotensos. Entre aqueles pacientes avaliados, nenhuma reação adversa foi observada. Concluiu-se que o NOVOCOL encontra-se dentro dos padrões necessários para a realização das manobras cirúrgicas aqui relatadas, sendo um anestésico seguro e eficaz

Displasia fibrosa dos maxilares / Fibrous dysplasia of the jaws: presentation of two surgical cases

Os autores tecem algumas consideraçöes a respeito da displasia fibrosa dos maxilares, juntamente com a descriçäo de dois casos clínicos, um ocorrido na mandíbula e outro, na maxila, que apresentavam aspectos radiográficos diversos