Immunohistochemical analysis revealed the expression of bone morphogenetic proteins-4, 6, 7, and 9 in human induced membrane samples treated with the Masquelet technique

Background Induced membrane (IM) is the key component of Masquelet reconstruction surgery for the treatment of bone defects. IM is formed around the cement spacer and is known to secrete growth factors and osteoinductive factors. However, there is limited evidence available concerning the presence of osteoinductive factors in IM. This study aimed to investigate the existence of bone morphogenetic proteins (BMPs) in IM harvested from patients during the treatment of bone defects using the Masquelet technique. Methods This study involved six patients whose bone defects had been treated using the Masquelet technique. The affected sites were the femur (n = 3) and the tibia (n = 3). During the second-stage surgery, 1 cm2 pieces of IM were harvested. Histological sections of IM were immunostained with anti-BMP-4, 6, 7, and 9 antibodies. Human bone tissue served as the positive control. Results The presence of BMP-4, 6, 7, and 9 was observed in all IM samples. Further, immunolocalization of BMP-4, 6, 7, and 9 was observed in blood vessels and fibroblasts in all IM samples. Immunolocalization of BMP-4, 6, 7, and 9 was also observed in bone tissue within the IM in one sample, in which osteogenesis inside the IM was observed. Conclusions This study showed that osteoinductive factors BMP-4, 6, 7, and 9 were present in the IM harvested from patients, providing evidence indicating that the Masquelet technique effectively contributes to healing large bone defects. Therefore, it may be possible for surgeons to omit the addition of BMPs to bone grafts, given the endogenous secretion of BMPs from the IM.

Immunohistochemical Analysis Revealed the Expression of Bone Morphogenetic Proteins-4, 6, 7, and 9 in Human Induced Membrane Samples Treated With the Masquelet Technique

BackgroundInduced membrane (IM) is the key component of Masquelet reconstruction surgery for the treatment of bone defects. It is formed around the cement spacer and is known to secrete growth factors and osteoinductive factors. However, information on the presence of osteoinductive factors in IM is not enough in the literature. The purpose of this study was to investigate the existence of bone morphogenetic proteins (BMPs) in the IM harvested from patients during the treatment of bone defects using the Masquelet technique.MethodsWe included six patients whose bone defects were treated using the Masquelet technique. The affected bone was the femur in three patients and the tibia in three patients. During the second-stage surgery, 1-cm2 pieces of IM were harvested. Histological sections of IM were immunostained with anti-BMP-4, 6, 7, and 9 antibodies. Human bone tissue served as the positive control.ResultsThe existence of BMP-4, 6, 7, and 9 was observed in all IM samples. Further, immunolocalization of BMP-4, 6, 7, and 9 was observed in blood vessels and fibroblasts of all IM samples. Immunolocalization of BMP-4, 6, 7, and 9 was also observed in bone tissue within the IM in one sample, in which osteogenesis inside the IM was observed.ConclusionsThis study revealed that osteoinductive factors BMP-4, 6, 7, and 9 were present in the IM harvested from patients. This helps explain how the Masquelet technique effectively contributes to the healing of large bone defects. It may thus be possible for surgeons to omit the addition of BMPs to bone grafts give the endogenous secretion of BMPs from the IM.Trial registrationNot applicable.

Biomechanical Properties of 3D-Printed Cervical Interbody Fusion Cage With Novel SF/nHAp Composites

Anterior cervical discectomy and fusion (ACDF) is a commonly used surgical method for the treatment of cervical spondylosis. As ACDF surgery is widely used in clinics, identifying suitable materials to design and prepare cervical interbody fusion cages is a hot research topic. Here, we describe a new three-dimensional (3D) printing approach to create stretchable and tough silk fibroin/nano-hydroxyapatite (SF/nHAp) composites with tunable mechanical properties. The compressive strength of the novel composites with biomimetic structure could reach more than 128 MPa. More importantly, the composites were prepared using 30% silk fibroin and 70% hydroxyapatite, a composition similar to the human bone tissue. Finite element analysis results indicate that the stress distribution of SF/nHAp composite cervical interbody fusion cages in vivo is more uniform than that of commercial Ti alloy cages. This study evaluates the effectiveness of SF/nHAp composites for application in cervical interbody fusion cages and in the field of bone tissue engineering.

Percolation networks inside 3D model of the mineralized collagen fibril

Bone is a hierarchical biological material, characterized at the nanoscale by a recurring structure mainly composed of apatite mineral and collagen, i.e. the mineralized collagen fibril (MCF). Although the architecture of the MCF was extensively investigated by experimental and computational studies, it still represents a topic of debate. In this work, we developed a 3D continuum model of the mineral phase in the framework of percolation theory, that describes the transition from isolated to spanning cluster of connected platelets. Using Monte Carlo technique, we computed overall 120 × 106 iterations and investigated the formation of spanning networks of apatite minerals. We computed the percolation probability for different mineral volume fractions characteristic of human bone tissue. The findings highlight that the percolation threshold occurs at lower volume fractions for spanning clusters in the width direction with respect to the critical mineral volume fractions that characterize the percolation transition in the thickness and length directions. The formation of spanning clusters of minerals represents a condition of instability for the MCF, as it could be the onset of a high susceptibility to fracture. The 3D computational model developed in this study provides new, complementary insights to the experimental investigations concerning human MCF.

Microbial flora of dentin of remote wisdom teeth

The aim of our study was to study the microbial flora of autodentin of removed wisdom teeth and compare it with the microbial flora of the oral cavity in order to determineits safe use as graft for thereplacement of defects of the alveolar bone. Relevance. The dental dentin is close in organic and mineral composition to human bone tissue. A bone autograft is considered the “gold standard” for ridge augmentation. However, a bone autograft graft increases the morbidity of reconstructive operations, requiring the formation of a donor zone, which increases the feeling of discomfort and the patient’s rehabilitation time. Increases the risk of intra- and postoperative complications. Materials and methods. A group of patients with wisdom teeth to be removed had smears taken from the mucous membrane in the area of the extracted teeth. After that, the teeth were removed, crushed using a bone mill manually, or reduced to thin plates, placed in nutrient media and sent for microbiological examination. Conclusions. According to the microbiological study, the microflora of the oral cavity and the microbial flora of the extracted teeth were identical, only quantitative indicators differed.

Brazilian dentists’ perceptions of using bone grafts: an inland survey

Pre-clinical assessments of bone substitute materials are frequent in the literature, but research papers about the clinical situation of bone graft use and consumer market acceptance are rare. The aim of this study was to evaluate the dental use of bone grafts according to the perception of dentists in the city of Sobral, Brazil. We interviewed 183 professionals and analyzed their professional data, knowledge of the subject, specific use, and opinions on cost-effectiveness and biosafety. Most of the respondents had 10 years’ or less experience in the profession, and lacked specialization though they had been familiar with the subject since they graduated. The most frequently mentioned compositions were ceramics, followed by composites. Only a quarter of the respondents had performed bone grafts, generally with up to 50 cases, with the most frequent applications being using simultaneously with a dental implant, fresh dental sockets and maxillary sinus lifting. Autogenous and xenogeneic grafts were more frequent than alloplastic and allogeneic; ceramics were the most frequently used composition, and the association of bone graft with membrane was more frequent than bone graft alone or associated with autologous fibrin. Professional and patient satisfaction was high, cost was considered moderate, and differences were found regarding patient participation in the choice and country of origin of the product. Bone grafts were used more often in the private than public service. Dentists stated that they follow the instructions. Inflammatory or infectious complications were found to be related to the frequency of the procedure performed and safety regarding the origin. Opinions were favorable regarding the use of grafts derived from animals and unfavorable to grafts derived from cadavers. Very few respondents were registered in human bone tissue banks. The good level of acceptance for dental use of bone grafts in a Brazilian inland city provides a promising scenario for the development of the sector.

ARG1 could be expressed by human, but not represent for repair

Arginase 1 (ARG1), typically expressed under stress or stimulation rather than in the healthy condition in humans. However, more and more studies claim ARG1 could be expressed by human and represents healing process. Including THP-1 monocyte shift to M2 macrophages rendered a higher expression of ARG1 than that with bone-graft has an ideal effect on anti-inflammation, resulting in tissue healing. With the higher expression of ARG1 seemingly induced by the constructed material and represented by the anti-inflammatory situation. For these reasons, this study focuses on whether traditional markers of macrophages could be express by human or not during clinical healing process. Through harvesting bone tissue samples during bone healing process and confirm the expression of markers at transcriptome and protein levels. The results showed the expression of ARG1 relatively low by bulk-RNA sequencing, quantitative polymerase chain reaction (qPCR), immunofluorescence (IF) and flow cytometry or could not be detected during process of healing of healthy donor. Taken together, results indicate that the ARG1 is not chosen for a regenerative marker in human bone tissue.