Lipid-Iron Nanoparticle with a Cell Stress Release Mechanism Combined with a Local Alternating Magnetic Field Enables Site-Activated Drug Release.

Most available cancer chemotherapies are based on systemically administered small organic molecules, and only a tiny fraction of the drug reaches the disease site. The approach causes significant side effects and limits the outcome of the therapy. Targeted drug delivery provides an alternative to improve the situation. However, due to the poor release characteristics of the delivery systems, limitations remain. This report presents a new approach to address the challenges using two fundamentally different mechanisms to trigger the release from the liposomal carrier. We use an endogenous disease marker, an enzyme, combined with an externally applied magnetic field, to open the delivery system at the correct time only in the disease site. This site-activated release system is a novel two-switch nanomachine that can be regulated by a cell stress-induced enzyme at the cellular level and be remotely controlled using an applied magnetic field. We tested the concept using sphingomyelin-containing liposomes encapsulated with indocyanine green, fluorescent marker, or the anticancer drug cisplatin. We engineered the liposomes by adding paramagnetic beads to act as a receiver of outside magnetic energy. The developed multifunctional liposomes were characterized in vitro in leakage studies and cell internalization studies. The release system was further studied in vivo in imaging and therapy trials using a squamous cell carcinoma tumor in the mouse as a disease model. In vitro studies showed an increased release of loaded material when stress-related enzyme and magnetic field was applied to the carrier liposomes. The theranostic liposomes were found in tumors, and the improved therapeutic effect was shown in the survival studies.

Survival of dental implants placed in vascularised fibula free flaps after jaw reconstruction.

PURPOSE: Ablative oncological surgery to treat head-and-neck cancer often triggers a requirement for jaw reconstruction. Modern surgical procedures using free microvascular flaps afford acceptable outcomes in terms of restoration of bony and soft tissue defects. A fibula free flap is often the preferred flap, as the bone length is considerable and a two-surgeon approach is possible. Dental implants play important roles in functional rehabilitation. Our aim was to evaluate the survival of dental implants placed in reconstructed areas after transfer of fibula tissue to the jaw. MATERIALS AND METHODS: We retrospectively studied 34 patients who underwent ablative tumour surgery and jaw reconstruction using osteocutaneous fibula free flaps and who then received dental implants. We evaluated implant survival and success, survival of the fibula flap, and clinical and radiographic data. RESULTS: We included 34 patients, 23 of whom were diagnosed with squamous cell carcinoma. In total, 134 dental implants were inserted in transferred fibula bone. The cumulative implant survival rate was 81%. The survival rate of the 34 fibula flaps transplanted after surgical reconstruction was 97%. CONCLUSION: The insertion of endosseous implants after jaw reconstruction using vascularised fibula tissue yields successful dental rehabilitation in patients with oral cancers.

Periodontal regeneration employing gingival margin-derived stem/progenitor cells in conjunction with IL-1ra-hydrogel synthetic extracellular matrix.

AIM: This study investigated the periodontal regenerative potential of gingival margin-derived stem/progenitor cells (G-MSCs) in conjunction with IL-1ra-releasing hyaluronic acid synthetic extracellular matrix (HA-sECM). MATERIALS AND METHODS: Periodontal defects were induced at four sites in eight miniature pigs in the premolar/molar area (-4 weeks). Autologus G-MSCs were isolated from the free gingival margin and magnetically sorted, using anti-STRO-1 antibodies. Colony formation and multilineage differentiation potential were tested. The G-MSCs were expanded and incorporated into IL-1ra-loaded/unloaded HA-sECM. Within every miniature pig, four periodontal defects were randomly treated with IL-1ra/G-MSCs/HA-sECM (test group), G-MSCs/HA-sECM (positive-control), scaling and root planing (SRP; negative control-1) or left untreated (no-treatment group; negative control 2). Differences in clinical attachment level (ΔCAL), probing depth (ΔPD), gingival recession (ΔGR), radiographic defect volume (ΔRDV), and changes in bleeding on probing (BOP) between baseline and 16 weeks post-transplantation, as well as periodontal attachment level (PAL), junctional epithelium length (JE), connective tissue adhesion (CTA), cementum regeneration (CR) and bone regeneration (BR) at 16 weeks post-transplantation were evaluated. RESULTS: Isolated G-MSCs showed stem/progenitor cell characteristics. IL-1ra loaded and unloaded G-MSCs/HA-sECM showed higher ΔCAL, ΔPD, ΔGR, PAL, CR and BR as well as a lower JE compared to their negative controls and improved BOP. CONCLUSION: G-MSCs in conjunction with IL-1ra-loaded/unloaded HA-sECM show a significant periodontal regenerative potential.

Increased infection rates of sinus floor elevations after the use of a bone filter.

OBJECTIVES: The collection of bone debris during the preparation of sinus floor augmentations is a commonly used technique for avoiding autologous bone transplants and thereby reducing donor site morbidity. However, the collected bone debris has a higher risk of bacterial contamination. The aim of this retrospective study was to analyse whether the use of a bone filter had an impact on the infection rates after sinus floor augmentation. MATERIALS AND METHODS: A retrospective analysis was conducted of 340 sinus floor elevations (136 using a bone filter) in 249 patients. The sinus floor elevations were performed with the lateral approach. RESULTS: Localised infection occurred in 7.0 % (24 of 340) of the sinus floor elevations. In 40.0 % of the cases, a bone filter was used, and in this group, the infection rate was 13.0 %. In the control group, the infection rate was 4.0 %. One hundred one patients received bone transplants from the iliac crest, and these patients had a lower infection rate of 2.0 %. Stepwise factor reduction, according to Akaike, showed the use of a bone filter to be the most relevant factor for postoperative infection. CONCLUSIONS: To reduce the amount of bacteria, full-mouth disinfection with chemical agents and a strict aspiration protocol should be used when a bone filter is applied. Antibiotic prophylaxis should be prescribed to reduce the risk of postoperative infections further. CLINICAL RELEVANCE: In use of a bone filter, there is the possibility of higher infection rates of sinus floor augmentations.

Tissue engineering of a vascularized bone graft of critical size with an osteogenic and angiogenic factor-based in vivo bioreactor.

Engineering a large vascularized bone graft is a much greater challenge than engineering small bone tissues. Although this is essentially feasible through an osteogenic factor-based in vivo bioreactor technique, the ossification needs improving. This study was aimed to investigate the possibility and efficacy of ectopic cultivation of sizeable bone grafts with large angiogenic and osteogenic factor-loaded natural bovine bone mineral (NBBM) scaffolds. For this purpose, six groups of sizeable composite scaffolds were constructed, consisting of a titanium mesh cage of NBBM or a mixture of NBBM/autogenous bone particles (AB), which were preloaded with 660 µg recombinant human bone morphogenetic protein-7 (rhBMP-7) and/or 4 µg recombinant human vascular endothelial growth factor165 (rhVEGF165). The scaffolds were implanted in bilateral latissimus dorsi muscles in eight pigs to construct in vivo bioreactors. Sequential fluorescence labeling was then applied to trace bone formation at the early stage. The implants were retrieved 12 weeks later. The undecalcified sections were observed in turn under the fluorescence microscope and light microscope to investigate early stage osteogenesis and histology. Moreover, new bone density (BD) was measured with histomorphometry. Compared with rhBMP-7-delivered NBBM scaffolds, rhVEGF165/rhBMP-7-delivered NBBM scaffolds were with more intense intra-scaffold osteogenesis at the early stage and the ultimate sizeable bone grafts of microstructurally more lamellae and trabeculae, and quantitatively higher BD (31.93% vs. 22.37%, p<0.01). This study demonstrated that as for the endocultivation of a large bone graft with bioactive factor-based in vivo bioreactor technique, dual delivery of rhVEGF165/rhBMP-7 has synergic effects on improving early stage bone formation and subsequently bone quality and quantity of the bone grafts.

A clinically-feasible protocol for using human platelet lysate and mesenchymal stem cells in regenerative therapies.

The transplantation of human stem cells seeded on biomaterials holds promise for many clinical applications in cranio-maxillo-facial tissue engineering and regenerative medicine. However, stem cell propagation necessary to produce sufficient cell numbers currently utilizes fetal calf serum (FCS) as a growth supplement which may subsequently transmit animal pathogens. Human platelet lysate (HPL) could potentially be utilized to produce clinical-grade stem cell-loaded biomaterials as an appropriate FCS substitute that is in line with clinically-applicable practice. The goal of this study was to investigate whether HPL can be successfully used to propagate human mesenchymal stem cells (HMSCs) seeded on clinically-approved collagen materials under clinically-applicable conditions using FCS as a control. HMSCs were isolated from bone marrow and cultured in the presence of 10% FCS or 10% HPL. Characterization of HMSCs was performed by flow cytometry and through osteogenic and adipogenic differentiation assays. Proliferative capacity of HMSCs on both matrices was investigated by mitochondrial dehydrogenase assays (WST) and tissue coverage scanning electron microscopy (SEM). The isolated HMSC differentiated into osteogenic and adipogenic cells authenticating the multipotentiality of the HMSCs. WST tests and the SEM images demonstrated that HPL was generally superior to FCS in promoting growth of seeded HMSCs. For all other tests HPL supported HMSCs at least equal to FCS. In conclusion, HPL is an effective growth factor to allow expansion of clinical-grade HMSCs on clinically-approved biomaterials for maxillofacial and oral implantology applications.

Comparison of two different absorbable membranes for the coverage of lateral osteotomy sites in maxillary sinus augmentation: a preliminary study.

INTRODUCTION: Barrier membranes, both absorbable and non-absorbable, have been used in sinus augmentation for many years. Some years ago, a new autologous blood substrate called Platelet-Rich-Fibrin (PRF) was introduced, and to date, the supporting effect on bone regeneration has been controversial. This study aimed to evaluate the effect of PRF on bone regeneration when used as a barrier membrane at the lateral osteotomy site in sinus augmentation. MATERIAL AND METHODS: Twelve sinuses from six patients requiring bilateral sinus floor augmentation were treated with a two-stage surgical technique using sinus augmentation and implant placement after 5 months. The sinuses were grafted with autologous bone and bone-substitute material (Bio-Oss(®)) mixed in a 1:1 ratio and were covered in a randomized split-mouth design with a PRF or a conventional collagen membrane (Bio-Gide(®)), respectively. Five months later threaded titanium dental implants were inserted and bone specimens harvested with a trephine burr were evaluated histomorphometrically. RESULTS: Bone quality seemed to be equal at both sites of the grafted sinuses. Mean vital bone formation after 5 months was 17.0% and 17.2%, for the PRF and collagen sites, respectively. The mean of residual bone-substitute was 15.9% and 17.3% for PRF and collagen, respectively. No local complications, such as dehiscences or membrane exposures, were detected at either site in any of the treated patients. After 12 months all implants reached primary stability in the augmented maxillary sinus floor without any peri-implant tissue inflammation. CONCLUSIONS: Within the limits of the study the coverage of the lateral sinus window with two different absorbable membranes has been shown to result in a similar amount of vital bone formation and residual bone-substitute.

The ongoing battle against multi-resistant strains: in-vitro inhibition of hospital-acquired MRSA, VRE, Pseudomonas, ESBL E. coli and Klebsiella species in the presence of plant-derived antiseptic oils.

The fight against hospital-acquired infections involving antibiotic-resistant microorganisms has become of critical concern to surgeons worldwide. In addition to the development of new effective antibiotic chemotherapy, exploration of 'forgotten' topical antibacterial agents from the pre-antibiotic era has recently gained new attention. We report the promising efficacy of plant-derived antiseptic oils used in traditional aboriginal and south-east Asian treatments such as Lemongrass, Eucalyptus and Tea Tree Oil in the inhibition of clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), multi-resistant Pseudomonas aeruginosa, ESBL-producing Escherichia coli and Klebsiella pneumoniae in the in-vitro setting. Large consistent zones of inhibition were observed for all three plant-derived oils tested in an agar diffusion test. The commonly used antibacterial agents chlorhexidine 0.1%, and ethanol (70%), and standard olive oil consistently demonstrated notably lower or no efficacy in regard to growth inhibition of strains. Notably, Lemongrass oil proved to be particularly active against gram-positive bacteria, while Tea Tree oil showed superior inhibition of gram-negative microorganisms. As proven in vitro, plant-derived antiseptic oils may represent a promising and affordable topical agent to support surgical treatment against multi-resistant and hospital-acquired infections.

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.

Survival of transplanted rat bone marrow-derived osteogenic stem cells in vivo.

This study was designed to trace bone marrow-derived stromal cells (MSC) after implantation in an ectopic rat model of bone tissue engineering. MSC were isolated from adult donor rats, expanded, seeded on a hydroxyapatite/ß-tricalcium phosphate bone graft substitute (Straumann® BoneCeramic), and cultivated until confluent. Before subcutaneous implantation of seeded constructs and controls (unseeded bone graft substitute) in isogenic rats (n = 32), cells were labeled with the fluorescent dye carboxyfluoresceine-diacetate-succinimidyl-ester. Specimens were harvested at sacrifice on day 1, 3, 7, or 14 after implantation (n = 8 per group) and processed for histology (hematoxylin and eosin, CD68, 4',6-diamidino-2-phenylindol). Carboxyfluoresceine-diacetate-succinimidyl-ester-labeled transplanted cells were quantified in decalcified sections (50 fields of view per specimen) at 488 nm. Over time, transplanted cells decreased in number from 31.3 ± 2.3 (day 1) to 9.2 ± 1.1 (day 3) and 0.3 ± 0.1 (day 7) (p < 0.001). Fourteen days postimplantation MSC could no longer be identified. Additionally, starting on day 3 postimplantation, cellular disintegration was noted. Multinucleated giant cells were present in constructs and controls on day 7 and increased to day 14 postimplantation. These results indicate that ectopically transplanted MSC survive for a rather short time after implantation. Possible reasons for early cell death are discussed.

Validation of histologic changes induced by external irradiation in mandibular bone. An experimental animal model.

The present experimental study sought to determine the effect of high-dose irradiation on the rat mandible in order to establish an experimental model of radiogenic bone damage. The left mandibles of 20 adult Wistar rats were irradiated (single fraction 1500cGy, total dose 60Gy) by means of a hypofractionated stereotactic radiotherapy (hfSRT) over a period of 6 weeks. Follow-up was 6 weeks (group 1, n=10) and 12 weeks (group 2, n=10). The contralateral mandibles as well as 5 non-irradiated animals served as controls. Primary endpoints were fibrosis, loss of cell count, decreased immunohistochemical labelling for bone morphogenetic protein-2 (BMP-2) and osteocalcin as well as increased expression of transforming growth factor (TGF-beta). Cell loss, progressive fibrosis, and focal necrosis were detected in all irradiated sites. Quantitative measurement revealed 32.0+/-8.7% and 37.3+/-9.5% empty osteocyte lacunae for groups 1 and 2 resp., compared to 16.3+/-4.7% and 18.9+/-4.9% on the contralateral side and 7.9+/-1.7% for unirradiated controls (Mann-Whitney U test; p<.01). BMP-2 and osteocalcin labelling showed a marked decrease in irradiated and contralateral sides while TGF-beta was expressed strongly in irradiated sites only (for all p<.05). External hypofractionated irradiation with a total dose of 60Gy is feasible in rats and yields all histologic changes attributed to osteoradionecrosis (ORN) after a follow-up of 6 weeks. The irradiation protocol is suitable for an assessment of regenerative options in severe radiogenic bone damage. As a split mouth design entails major inaccuracies healthy animals have to be used as controls.

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 (H(2)O(2)) 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.

Expression of melanoma-associated antigens in oral squamous cell carcinoma.

BACKGROUND: Melanoma-associated antigens-A (MAGE-A) are expressed in a variety of tumors but not in normal tissues. Thus, their detection is highly specific to cancer cells, which makes them potential targets for the diagnosis, prognosis and also immunotherapy of neoplastic diseases. METHODS: To determine the expression pattern and potential role of MAGE-A antigens in oral squamous cell carcinoma (OSCC), expression patterns of MAGE-A1-A6 and A12 were analyzed in 55 OSCC and 20 healthy oral mucosa using high-sensitive reverse transcription-nested polymerase chain reaction (RT-nPCR). RESULTS: The 85.45% of tumor specimens expressed at least one of these genes. A significant correlation between the expression of MAGE-A1-A6 and A12 and malignancy was ascertained (P = 0.0001). On the contrary, none of the normal mucosal specimens expressed one of the MAGE-A subtypes. Antigen expression did not correlate with clinicopathological parameters, such as TNM classification, grading and clinical stage of OSCC. CONCLUSIONS: Multiple simultaneous detection of MAGE-A1-A6 and A12 expression has been found to be more specific and sensitive than the detection of single MAGE-A antigen for the diagnostic and prognostic evaluation of OSCC. In addition, monitoring the expression of several MAGE-A subtypes may determine suitable immunotherapeutic targets. Subsequently, coexpressed genes may be warranted for developing polyvalent vaccines.

Expression of bone matrix proteins during the osseus healing of topical conditioned implants: an experimental study.

OBJECTIVES: Osseointegration of implants depends on time and local bone conditions regarding quality and quantity. This led to the bone classification by Lekholm et al. The aim of the present study was to follow the expression of bone matrix proteins during the phase of osseointegration after conditioning of the bone bed by means of immunohistochemistry. METHODS: In the porcine frontal skull, implant beds of identical size were created. Before placement of the implants (Ankylos 4 x 3.5 mm), the implant beds were conditioned using bone condensation (cond), an osteoinductive collagen (Co) and platelet-rich plasma (PRP). These conditioning methods were compared with standard procedure. The animals were sacrificed after 2, 4 and 8 weeks. The specimens were then analyzed by light microcopy and immunohistochemistry for expression of bone morphogenic proteins (BMP)2, procollagen I and osteocalcin (OC). RESULTS: Light microscopy revealed an initial effect of condensation and the bovine collagen at 2 weeks in comparison with the standard group. The PRP did not achieve a significant effect. At 8 weeks, the results of the standard, bone condensation and the bovine collagen group had aligned. The PRP group showed a significantly lower bone-implant contact (BIC) (P=0.003) compared with the standard group. BMP2 expression was significantly higher in all evaluated test groups at 4 and 8 weeks, as well as at 2 weeks in the condensation group. The procollagen I expression at 2 weeks was significantly increased for PRP and lower in the collagen and condensation group compared with standard procedure. Values for 4 and 8 weeks were slightly higher than in the standard group. No significant differences were obvious in the OC group at any time. CONCLUSIONS: During the initial healing phase, an effect of the evaluated methods of topical bone conditioning can be demonstrated by differences in the expression of BMP2 and procollagen I. These findings had leveled at 8 weeks and were, in contrast, not detectable in the expression of OC or by means of light microscopy.

Lack of beneficial effects of platelet-rich plasma on sinus augmentation using a fluorohydroxyapatite or autogenous bone: an explorative study.

BACKGROUND: Maxillary sinus augmentation is frequently necessary before placement of dental implants in the posterior maxilla. Besides autogenous bone graft, various bone substitutes have been used, with favourable results. Although platelet-rich plasma (PRP) has been used in the field of oral and maxillofacial surgery for years, its beneficial effects on osseous regeneration still remain unclear. The aim of this study was to evaluate the short and long time effects of PRP on single-stage sinus augmentation using autogenous bone or a fluorohydroxyapatite (Algipore) in a randomized prospective animal study. METHODS: After extraction of maxillary premolars of sixteen minipigs, the wounds were allowed to heal for 2 months. Then, sinus augmentations were performed bilaterally using one of the following grafting materials: autogenous bone and Algipore with or without PRP. Three dental implants (Ankylos) were installed in each sinus simultaneously. Four animals were euthanized at each period of observation (1, 2, 8 and 12 months). Implant-bearing specimens were sectioned bucco-lingually along the long axis of implants and undecalcified ground specimens were prepared. The bone-implant-contact (BIC) was measured by means of microradiographic examination. For histological evaluation, the specimens were stained with toluidin blue, and the percentage of the newly formed bone and the remaining bone substitute were evaluated. RESULTS: The grafting materials chosen showed increasing levels of BIC and newly formed bone throughout the period of observation in both PRP and non-PRP groups. Adding PRP resulted in lower BIC and newly formed bone compared with autogenous bone grafts or Algipore alone. However, a statistical significance was not found. The percentages of the remaining bone substitute in both the PRP and non-PRP groups were closely comparable in all observation periods. CONCLUSIONS: The application of PRP could not reveal significant beneficial effects on the BIC, the percentage of the newly formed bone and the remaining bone substitute in this study.

Influence of platelet-rich plasma on a bioglass and autogenous bone in sinus augmentation. An explorative study.

Platelet-rich plasma (PRP) has been introduced to the field of oral and maxillofacial surgery for a decade, but its beneficial effects on maxillary sinus augmentation remain unclear. The aim of this study was to evaluate the short- and long-term effects of PRP on osseointegration following single-stage sinus augmentation in a randomized prospective animal study. The maxillary premolars of 24 minipigs were extracted bilaterally and allowed to heal for 2 months. Consecutively all animals underwent bilateral sinus floor elevation using autogenous bone, Biogran as well as a combination of the materials with PRP. Three dental implants (Ankylos, Dentsply Co., Mannheim, Germany) were installed in each sinus simultaneously. Four animals were sacrificed at each period of observation (1, 2, 8 and 12 months). Microradiographic images of the specimens were made for quantitative evaluation of the bone-implant contact (BIC) and light microscopic images were made for qualitative analysis. An increment of the BIC during the observation time could be seen over the observation time in all groups. Autogenous bone exhibited a level of BIC from 25.1 +/- 9.96% at 1 month to 55.1 +/- 13.10% at 12 months; on adding PRP, the BIC ranged from 28.4 +/- 4.64% to 52.5 +/- 17.06%. Biogran with and without PRP led to BIC levels from 16.3 +/- 4.64% to 37.6 +/- 16.40% and 21.7 +/- 4.33% to 46.6 +/- 19.37%, respectively. The results of this study did not show a significantly positive effect of PRP on the BIC following sinus augmentation in both groups.

Bone regeneration in osseous defects using a resorbable nanoparticular hydroxyapatite.

PURPOSE: This animal study examined the de novo bone formation in bony defects following the insertion of autogenous bone alone versus an injectable nanoparticle hydroxyapatite alone and in combination with 25% autogenous bone. The regenerative potentials of the tested materials were compared with each other. MATERIALS AND METHODS: A model with biological similarity to humans with regard to bone regeneration was a prerequisite for the transferability of the results to clinical practice. Therefore, the adult domestic pig was the animal of choice. A total observation period of 6 months was selected. Microradiographic and histologic evaluation of the bone specimens was completed at 8 defined times. RESULTS: Microradiography indicated mineralization rates in the 2 bone substitute groups that were not significantly lower than those found in the autogenous bone group. Histologically, there was suitable osseointegration and osteoconduction of the used material. Complete resorption of the nanoparticle hydroxyapatite had taken place after 12 weeks. CONCLUSIONS: It can be concluded that the evaluated nanoparticular hydroxyapatite met the clinical requirements for a bone substitute material within the limits of this experimental setting. Due to its microstructure, complete resorption took place during the course of this study.

Untreated 'blow-in' fracture of the orbital floor causing a mucocele: report of an unusual late complication.

BACKGROUND: Several severe complications have been described with blow-in fractures. Therefore, immediate surgical treatment of these fractures has been recommended. To date, there is only minimal knowledge on long-term complications of blow-in fractures that have remained untreated. The present case report describes a late complication of an untreated blow-in fracture of the orbital floor. CASE: A 37-year-old male was involved in a car accident 16 years before. At that time, a non-dislocated midfacial fracture was diagnosed and remained untreated because of the lack of clinical symptoms. Four months before surgery an exophthalmos of the left globe began to develop. CT examination revealed a consolidated blow-in fracture of the left orbital floor and an opaque mass around the dislocated bony fragments. By an infraorbital approach the bony fragments and the surrounding mass were removed. Histological examination of the removed material revealed a cystic structure lined with respiratory epithelium. Therefore, the diagnosis 'post-traumatic mucocele in the orbit caused by dislocated respiratory epithelium from the maxillary sinus' was made. CONCLUSION: Even if blow-in fractures do not cause complications immediately after trauma, late complications like mucoceles can occur after several symptom-free years. Therefore, early reconstruction should be intended even in asymptomatic cases of blow-in fractures with minimal displacement of the bony fragments.

Enhanced bone regeneration with a synthetic cell-binding peptide--in vivo results.

This in vivo study compared the regenerative processes within defined defects of the porcine skull after delivery of a porous algae-derived hydroxyapatite (adHA), a similar, experimental adHA carrying the cell binding peptide P-15, used solely and in combination with 25% autogenous bone (AB). Particulated AB served as a control group. During an observation period of 26 weeks, microradiography and histology were performed at four specific times. Significantly higher mineralization rates (p=0.008) were found 4 weeks after application of the bioactive material in combination with AB. At 12 weeks there was a significantly higher mineralization (p=0.036) following the application of the bioactive form alone. This study showed significantly higher mineralization after use of a P-15 bioactivated material at early stages. Thus, it can be concluded that the application of the P-15 sequence to an hydroxyapatite accelerates the process of early bone formation, whereas no long-term effect was traced.

Investigation of the expression of melanoma antigen-encoding genes (MAGE-A1 to -A6) in oral squamous cell carcinomas to determine potential targets for gene-based cancer immunotherapy.

MAGE genes are silent in normal tissues except testis but are expressed in a variety of neoplastic lesions, and therefore represent ideal targets for immunotherapy. We analysed the expression of 6 MAGE-A genes (MAGE-A1 to -A6) to determine potential implications of these antigens as targets for immunotherapy in oral squamous cell carcinoma (OSCC). Oral tumor specimens (n=21) and non-neoplastic tissue samples (n=10) of oral mucosa from healthy patients were examined by a highly sensitive reverse transcription-nested polymerase chain reaction (MAGE-1- to -6 assay) which detect any cancer cells that express at least one of six MAGE subtype genes and allows also the identification of individual MAGE isotypes (M1 to M6). MAGE expression was restricted to neoplastic specimens. No expression of MAGE was observed in the non-neoplastic normal oral mucosal tissues. Fifteen of 21 (71%) oral carcinomas expressed at least one of MAGE-A1 to -6. The expression pattern of subtypes was heterogeneous: 62% of the tumor patients were positive for MAGE-3, 57% for MAGE-4, 48% for MAGE-6, 43% for MAGE-1, 38% for MAGE-2 and 24% for MAGE-5. Also coexpression of the genes could be determined: 13 (62%) coexpressed two, 10 (48%) coexpressed three, 8 (38%) coexpressed four, 6 (29%) coexpressed five and 5 coexpressed six of the 6 subtypes tested. The high incidence of MAGE expression in oral cancer indicates that monitoring of MAGE-A subtype expression in OSCC may be of potential interest to determine new immunotherapeutic targets and may be a possibility of specific immunotherapy with polyvalent anti-genes for this disease.