Three-dimensional printing of porous load-bearing bioceramic scaffolds

This article reports on the use of the binder jetting three-dimensional printing process combined with sintering to process bioceramic materials to form micro- and macroporous three-dimensional structures. Three different glass-ceramic formulations, apatite–wollastonite and two silicate-based glasses, have been processed using this route to create porous structures which have Young’s modulus equivalent to cortical bone and average bending strengths in the range 24–36 MPa. It is demonstrated that a range of macroporous geometries can be created with accuracies of ±0.25 mm over length scales up to 40 mm. Hot-stage microscopy is a valuable tool in the definition of processing parameters for the sintering step of the process. Overall, it is concluded that binder jetting followed by sintering offers a versatile process for the manufacture of load-bearing bioceramic components for bone replacement applications

Protein-Signaled Guided Bone Regeneration Using Titanium Mesh and Rh-BMP2 in Oral Surgery: A Case Report Involving Left Mandibular Reconstruction after Tumor Resection

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is an osteoinductive protein approved for use in oral and maxillofacial defect reconstruction. Growth factors act as mediators of cellular growth on morphogenesis and mythogenesis phases. Utilized as recombinant proteins, these growth factors need the presence of local target cells capable of obtaining the required results. This cell population may be present at the wound site or added to scaffolding material before implantation at the surgical site

Hard Tissue Engineering

Peer reviewe

Increased human defensine levels hint at an inflammatory etiology of bisphosphonate-associated osteonecrosis of the jaw: An immunohistological study

<p>Abstract</p> <p>Background</p> <p>Human β-defensins (hBD) are antimicrobial peptides that are an integral part of bone innate immunity. Recently, it could be shown that expression of hBD-1, -2 and -3 were upregulated in cases of osteomyelitis of the jaws. In order to gain insight into the possible impairment of hBD metabolism in bisphosphonate-associated osteonecrosis of the jaws (BONJ), the present exploratory study was designed so as to determine the qualitative and quantitative expression of afore mentioned hBDs in BONJ and infected osteoradionecrosis (ORN), both of which represent inflammatory bone diseases.</p> <p>Methods</p> <p>Bone samples were collected from patients with BONJ (n = 20) and ORN (n = 20). Non-infected healthy bone samples (n = 20) were included as controls. Immunohistological staining in an autostainer was carried out by the (Strept-ABC)-method against hBD-1,-2,-3. Specific positive vs. negative cell reaction of osteocytes (labeling index) near the border of bony resection was determined and counted for quantitative analysis. Number of vital osteocytes vs. empty osteocytes lacunae was compared between groups.</p> <p>Results</p> <p>hBD-1,-2 and -3 could be detected in BONJ as well as ORN and healthy bone samples. Immunoreactivity against hBD-2 and -3 was significantly higher in BONJ than in ORN and healthy jaw bone samples. Number of empty osteocyte lacunae was significantly higher in ORN compared with BONJ (<it>P </it>= 0.001).</p> <p>Conclusion</p> <p>Under the condition of BONJ an increased expression of hBD-1,-2,-3 is detectable, similarly to the recently described upregulation of defensins in chronically infected jaw bones. It remains still unclear how these findings may relate to the pathoetiology of these diseases and whether this is contributing to the development of BONJ and ORN or simply an after effect of the disease.</p

Tissue Engineering in Oral and Maxillofacial Surgery : From Lab to Clinics

Regenerative medicine aims at the functional restoration of tissue malfunction, damage or loss, and can be divided into three main approaches. Firstly, the cell-based therapies, where cells are administered to re-establish a tissue either directly or through paracrine functions. Secondly, the often referred to as classical tissue engineering, consisting of the combined use of cells and a bio-degradable scaffold to form tissue. Thirdly, there are material-based approaches, which have made significant advances which rely on biodegradable materials, often functionalized with cellular functions (De Jong et al. 2014). In 1993, Langer and Vacanti, determined tissue engineering as an “interdisciplinary field that applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function”. They published this definition in Science in 1993. Tissue engineering has been classically thought to consist of three elements: supporting scaffold, cells and regulating factors such as growth factors (Fig. 1). Depending on the tissue to be regenerated, all three vary. Currently, it is known, that many other factors may have an effect on the outcome of the regenerate. These include factors enabling angiogenesis, physical stimulation, culture media, gene delivery and methods to deliver patient specific implants (PSI) (Fig. 2). During the past two decades, major obstacles have been tackled and tissue engineering is currently being used clinically in some applications while in others it is just taking its first baby steps.Peer reviewe

Associations of homelessness and residential mobility with length of stay after acute psychiatric admission

Background: A small number of patient-level variables have replicated associations with the length of stay (LOS) of psychiatric inpatients. Although need for housing has often been identified as a cause of delayed discharge, there has been little research into the associations between LOS and homelessness and residential mobility (moving to a new home), or the magnitude of these associations compared to other exposures. Methods: Cross-sectional study of 4885 acute psychiatric admissions to a mental health NHS Trust serving four South London boroughs. Data were taken from a comprehensive repository of anonymised electronic patient records. Analysis was performed using log-linear regression. Results: Residential mobility was associated with a 99% increase in LOS and homelessness with a 45% increase. Schizophrenia, other psychosis, the longest recent admission, residential mobility, and some items on the Health of the Nation Outcome Scales (HoNOS), especially ADL impairment, were also associated with increased LOS. Informal admission, drug and alcohol or other non-psychotic diagnosis and a high HoNOS self-harm score reduced LOS. Including residential mobility in the regression model produced the same increase in the variance explained as including diagnosis; only legal status was a stronger predictor. Conclusions: Homelessness and, especially, residential mobility account for a significant part of variation in LOS despite affecting a minority of psychiatric inpatients; for these people, the effect on LOS is marked. Appropriate policy responses may include attempts to avert the loss of housing in association with admission, efforts to increase housing supply and the speed at which it is made available, and reforms of payment systems to encourage this

Phytotherapeutic and naturopathic adjuvant therapies in otorhinolaryngology

Phytotherapeutic pharmaceuticals and herbal medicinal products with its roots in classical phytotherapeutic medicine have a well-established role in otolaryngological therapy, especially for diseases of the upper airways and acute and chronic infections. A thorough selection and application could mean huge benefit for the patient, in particular in cases with contraindications, chemo- and antibiotic resistance or patient request. Besides, it might spare other medications. Phytotherapeutic pharmaceuticals must fulfil the same criteria of quality, effectiveness and harmlessness of evidence-based medicine like chemical pharmaceuticals, although they are often prescribed due to its well established or traditional based use. This review focuses on phytotherapeutic therapies well established within the European Community for otolaryngologic disease patterns by referring to clinical studies or meta-analysis

Methanotrophy, Methylotrophy, the Human Body and Disease

Methylotrophic Bacteria use one-carbon (C1) compounds as their carbon source. They have been known to be associated to the human body for almost 20 years as part of the normal flora and were identified as pathogens in the early 1990s in end-stage HIV patients and chemotherapy patients. In this chapter, I look at C1 compounds in the human body and exposure from the environment and then consider Methylobacterium spp. and Methylorubrum spp. in terms of infections, its role in breast and bowel cancers; Methylococcus capsulatus and its role in inflammatory bowel disease, and Brevibacterium casei and Hyphomicrobium sulfonivorans as part of the normal human flora. I also consider the abundance of methylotrophs from the Actinobacteria being identified in human studies and the potential bias of the ionic strength of culture media and the needs for future work. Within the scope of future work, I consider the need for the urgent assessment of the pathogenic, oncogenic, mutagenic and teratogenic potential of Methylobacterium spp. and Methylorubrum spp. and the need to handle them at higher containment levels until more data are available