The primordium of a biological joint replacement:Coupling of two stem cell pathways in biphasic ultrarapid compressed gel niches

The impaired temporomandibular joint might be the first to benefit from applied tissue engineering techniques because it is small and tissue growth in larger amounts is challenging. Bone and cartilage require different competing environmental conditions to be cultivated in vitro. But coupling both the osteogenic and cartilaginous pathways of mesenchymal stem cell differentiation in homeostasis will be a key essential to grow osteochondral constructs or even the first biological joint replacement in the future. The aim of this study was to test a single source biomaterial and a single source cell type to engineer a biphasic osteochondral construct in vitro for future in vivo implantation. Ultrarapid tissue engineering techniques were used to create the biphasic matrix and primary human mesenchymal stem cells (MSCs) preconditioned in osteogenic and chondrogenic media were then seeded in opposite portions of the hyper-hydrated collagen gel in order to further substantiate the respective bone-like and cartilage-like layers thus potentially customising the collagen scaffold according to patient needs in regards to future biological joint replacements. After incubation for 7 days to allow cell growth and differentiation, mineralization of the bone-like layer was demonstrated using von Kossa staining and biochemical bone markers. The cartilage-like layer was demonstrated using alcian blue staining and biochemical cartilage markers. Integration of the bone-like and cartilage-like layers to simulate a tidemark layer was achieved through partial setting of the gels. Cell tracking was used to further confirm the establishment of distinct cartilage-like and bone-like areas within the single construct. This is the first report of one homogeneous human MSC population differentiating into dissimilar "bone-like" and "cartilage-like" zones hosted in a biphasic ultrarapid compressed gel phase niche and mimicking a primordial joint-like structure. © 2010 European Association for Cranio-Maxillo-Facial Surgery

The battle against multi-resistant strains: Renaissance of antimicrobial essential oils as a promising force to fight hospital-acquired infections

Hospital-acquired infections and antibiotic-resistant bacteria continue to be major health concerns worldwide. Particularly problematic is methicillin-resistant Staphylococcus aureus (MRSA) and its ability to cause severe soft tissue, bone or implant infections. First used by the Australian Aborigines, Tea tree oil and Eucalyptus oil (and several other essential oils) have each demonstrated promising efficacy against several bacteria and have been used clinically against multi-resistant strains. Several common and hospital-acquired bacterial and yeast isolates (6 Staphylococcus strains including MRSA, 4 Streptococcus strains and 3 Candida strains including Candida krusei) were tested for their susceptibility for Eucalyptus, Tea tree, Thyme white, Lavender, Lemon, Lemongrass, Cinnamon, Grapefruit, Clove Bud, Sandalwood, Peppermint, Kunzea and Sage oil with the agar diffusion test. Olive oil, Paraffin oil, Ethanol (70%), Povidone iodine, Chlorhexidine and hydrogen peroxide (H2O2) served as controls. Large prevailing effective zones of inhibition were observed for Thyme white, Lemon, Lemongrass and Cinnamon oil. The other oils also showed considerable efficacy. Remarkably, almost all tested oils demonstrated efficacy against hospital-acquired isolates and reference strains, whereas Olive and Paraffin oil from the control group produced no inhibition. As proven in vitro, essential oils represent a cheap and effective antiseptic topical treatment option even for antibiotic-resistant strains as MRSA and antimycotic-resistant Candida species

Proliferation assessment of primary human mesenchymal stem cells on collagen membranes for guided bone regeneration

Abstract PURPOSE: Human mesenchymal stem cells (hMSCs) hold the potential for bone regeneration because of their self-renewing and multipotent character. The goal of this study was to evaluate the influence of collagen membranes on the proliferation of hMSCs derived from bone marrow. A special focus was set on short-term eluates derived from collagen membranes, as volatile toxic materials washed out from these membranes may influence cell behavior during the short time course of oral surgery. MATERIALS AND METHODS: The proliferation of hMSCs seeded directly on a collagen membrane (BioGide) was evaluated quantitatively using the cell proliferation reagent WST-1 (4-3-[4-iodophenyl]-2-[4-nitrophenyl]-2H-[5-tetrazolio]-1, 3--benzol-disulfonate) and qualitatively by scanning electron microscopy. Two standard biocompatibility tests, namely the lactate dehydrogenase and MTT (3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazoliumbromide) tests, were performed using hMSCs cultivated in eluates from membranes incubated for 10 minutes, 1 hour, or 24 hours in serum-free cell culture medium. The data were analyzed statistically. RESULTS: Scanning electron microscopy showed large numbers of hMSCs with well-spread morphology on the collagen membranes after 7 days of culture. The WST test revealed significantly better proliferation of hMSCs on collagen membranes after 4 days of culture compared to cells cultured on a cover glass. Cytotoxicity levels were low, peaking in short-term eluates and decreasing with longer incubation times. CONCLUSION: Porcine collagen membranes showed good biocompatibility in vitro for hMSCs. If maximum cell proliferation rates are required, a prewash of membranes prior to application may be useful.No Full Tex

Antimicrobial peptide immunity protects human nasal and auricular cartilage against infection

Background: Despite being impervious to surveillance by the adaptive immune system because of its lack of vascularity, infection of the nasal and auricular cartilage after surgery such as rhinoplasty or otoplasty is rare. Why is this so? Our goal was to determine whether the expression of antimicrobial peptides provides a previously unrecognized nonepithelial layer of innate immune defense within the nasal and auricular cartilage. Materials and Methods: Seven samples of nasal septum cartilage and 2 biopsies from auricular cartilage grafts were harvested during rhinoplasty and otoplasty procedures. Ten cadaveric samples of auricular and 9 samples of nasal cartilage were also obtained. Immunohistochemical staining was directed against the human β-defensin antimicrobial peptides (hBD) 1, 2, and 3. A semiquantitative analysis was performed to measure immunoreactivity. Results: All 3 human β-defensins were detected along the perichondral line and within the cartilage matrix in the nasal and auricular samples. Areas with positive immunohistochemical staining were also detected within chondrocyte cytoplasm. Conclusions: We provide the first evidence of antimicrobial peptide expression (hBD-1, -2 and -3) within the perichondrium and cartilage matrix layers of the nasal and auricular cartilage. This previously unrecognized innate immune function of perichondrocytes and chondrocytes may explain the resistance of the nasal and auricular cartilage to infection after surgical procedures despite the absence of a vascular system

A review of the efficacy of intraarticular hip injection for patients with hip osteoarthritis: to inject or not to inject in hip osteoarthritis?

Hip injection (HI) for osteoarthritis (OA) are in vogue nowadays. Corticosteroids (CSs) and hyaluronic acid (HA) gel are the two most common agents injected into the hip. Off late, platelet-rich plasma (PRP), mesenchymal stem cell (MSC), bone marrow aspirate concentrate (BMAC), local anesthetic (LA) agents, non-steroidal anti-inflammatory drugs (NSAIDs) and their different combinations have also been injected in hips to provide desired pain relief. However, there is a group of clinicians who vary of these injections. A search of the literature was performed on PubMed, Cochrane Library, and DOAJ using the keywords “hip osteoarthritis injection”. Data were analyzed and compiled. Intraarticular CSs are effective in providing the desired pain relief in OA hip, but repeated injections should be avoided and the interval between HI and hip arthroplasty must be kept for more than three months. Methylprednisolone or triamcinolone are combined with 1% lidocaine or 0.5% bupivacaine. Chondrotoxic effects of LA is a concern. Although national guidelines do not favor the use of HA for hip OA, numerous publications have favored its usage for a moderate grade of OA. The PRP, MSC, and BMAC are treatment options with great potential; however, currently, the evidence is conflicting on their role in hip OA. There is always a risk of septic arthritis, particularly when aseptic precautions are not followed, and clinicians must vary of this complication. The use of hip injection (HI) in the treatment of osteoarthritis (OA) has gained wide popularity. The relatively low cost, fast and simple method of pain relief are amongst its many advantages. Over time, the content of the injection has also evolved from local anesthetic (LA) agents to corticosteroids (CSs), hyaluronic acid (HA) and platelet-rich plasma (PRP).[1] The scope of use of injections in the hip region has grown from traditional aspiration to therapeutic injections. The two main substances used in recent times for pain relief are CSs and HA gel. For decades, low doses of CS were given to surgically unfit patients and to those who are not keen on joint replacement surgery.[2] The recent surge in the use of high-molecularweight HA for knee OA has been expanded as a treatment option for hip OA. The popularity of the administration of HA has been mounting with very little outcome data to support its use. Administration of HA injections has shown some promise in a selected subset of patients suffering from early OA of the hip.[3,4] Most papers report insufficient sample size and had a varied follow-up period which results in difficulty formulating and implementing national guidelines and clinical recommendations. Current literature advocates the safe use of CS injections for early hip OA.[5] Although there is no concrete evidence supporting HA injections, this has not dissuaded researchers from injecting PRP, mesenchymal stem cells (MSCs), LA agents, NSAIDS and many different combinations into the hip. The true extent of their benefits is still being debated.[6] In this review, we outline recent trends, discuss the role of HIs, and summarize complications of the technique

Comparison of in vitro biocompatibility of NanoBone^® and BioOss^® for human osteoblasts

Introduction: Scaffolds for bone tissue engineering seeded with the patient's own cells might be used as a preferable method to repair bone defects in the future. With the emerging new technologies of nanostructure design, new synthetic biomaterials are appearing on the market. Such scaffolds must be tested in vitro for their biocompatibility before clinical application. However, the choice between a natural or a synthetic biomaterial might be challenging for the doctor and the patient. In this study, we compared the biocompatibility of a synthetic bone substitute, NanoBoneto the widely used natural bovine bone replacement material BioOss Material and methods: The in vitro behaviour of human osteoblasts on both materials was investigated. Cell performance was determined using scanning electron microscopy (SEM), cell vitality staining and four biocompatibility tests (LDH, MTT, WST, BrdU). Results: We found that both materials showed low cytotoxicity and good biocompatibility. The MTT proliferation test was superior for Nanobone Discussion: Both scaffolds caused only little damage to human osteoblasts and justify their clinical application. However, NanoBoneas able to support and promote proliferation of human osteoblasts slightly better than BioOssn our chosen test set-up. The results may guide doctors and patients when being challenged with the choice between a natural or a synthetic biomaterial. Further experiments are necessary to determine the comparison of biocompatibility in vivo.No Full Tex

“Bring Your Own Device”—A New Approach to Wearable Outcome Assessment in Trauma

Background and Objectives: Outcome data from wearable devices are increasingly used in both research and clinics. Traditionally, a dedicated device is chosen for a given study or clinical application to collect outcome data as soon as the patient is included in a study or undergoes a procedure. The current study introduces a new measurement strategy, whereby patients’ own devices are utilized, allowing for both a pre-injury baseline measure and ability to show achievable results. Materials and Methods: Patients with a pre-existing musculoskeletal injury of the upper and lower extremity were included in this exploratory, proof-of-concept study. They were followed up for a minimum of 6 weeks after injury, and their wearable outcome data (from a smartphone and/or a body-worn sensor) were continuously acquired during this period. A descriptive analysis of the screening characteristics and the observed and achievable outcome patterns was performed. Results: A total of 432 patients was continuously screened for the study, and their screening was analyzed. The highest success rate for successful inclusion was in younger patients. Forty-eight patients were included in the analysis. The most prevalent outcome was step count. Three distinctive activity data patterns were observed: patients recovering, patients with slow or no recovery, and patients needing additional measures to determine treatment outcomes. Conclusions: Measuring outcomes in trauma patients with the Bring Your Own Device (BYOD) strategy is feasible. With this approach, patients were able to provide continuous activity data without any dedicated equipment given to them. The measurement technique is especially suited to particular patient groups. Our study’s screening log and inclusion characteristics can help inform future studies wishing to employ the BYOD design

Porous polymer/hydroxyapatite scaffolds: characterization and biocompatibility investigations.

Contains fulltext : 79508.pdf (Publisher’s version ) (Closed access)Poly-lactic-glycolic acid (PLGA) has been widely used as a scaffold material for bone tissue engineering applications. 3D sponge-like porous scaffolds have previously been generated through a solvent casting and salt leaching technique. In this study, polymer-ceramic composite scaffolds were created by immersing PLGA scaffolds in simulated body fluid, leading to the formation of a hydroxyapatite (HAP) coating. The presence of a HAP layer was confirmed using scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy in attenuated total reflection mode. HAP-coated PLGA scaffolds were tested for their biocompatibility in vitro using human osteoblast cell cultures. Biocompatibility was assessed by standard tests for cell proliferation (MTT, WST), as well as fluorescence microscopy after standard cell vitality staining procedures. It was shown that PLGA-HAP composites support osteoblast growth and vitality, paving the way for applications as bone tissue engineering scaffolds

Biocompatibility of individually designed scaffolds with human periosteum for use in tissue engineering.

Contains fulltext : 88733.pdf (Publisher’s version ) (Closed access)The aim of this study was to evaluate and compare the biocompatibility of computer-assisted designed (CAD) synthetic hydroxyapatite (HA) and tricalciumphosphate (TCP) blocks and natural bovine hydroxyapatite blocks for augmentations and endocultivation by supporting and promoting the proliferation of human periosteal cells. Human periosteum cells were cultured using an osteogenic medium consisting of Dulbecco's modified Eagle medium supplemented with fetal calf serum, Penicillin, Streptomycin and ascorbic acid at 37 degrees C with 5% CO(2). Three scaffolds were tested: 3D-printed HA, 3D-printed TCP and bovine HA. Cell vitality was assessed by Fluorescein Diacetate (FDA) and Propidium Iodide (PI) staining, biocompatibility with LDH, MTT, WST and BrdU tests, and scanning electron microscopy. Data were analyzed with ANOVAs. Results: After 24 h all samples showed viable periosteal cells, mixed with some dead cells for the bovine HA group and very few dead cells for the printed HA and TCP groups. The biocompatibility tests revealed that proliferation on all scaffolds after treatment with eluate was sometimes even higher than controls. Scanning electron microscopy showed that periosteal cells formed layers covering the surfaces of all scaffolds 7 days after seeding. Conclusion: It can be concluded from our data that the tested materials are biocompatible for periosteal cells and thus can be used as scaffolds to augment bone using tissue engineering methods.1 april 201