Xenogenic Material Research Articles

An optimized cultivation method for future in vivo application of γδ T cells.

γδ T cells, with their properties of both the innate and acquired immune systems, are suitable candidates for cellular immunotherapy in cancer. Because of their non-major histocompatibility complex (MHC) binding T cell receptor, allogenic transfer is feasible without relevant graft versus host reactions. In recent years, much experience has been gained with ex vivo expansion and stimulation of γδ T cells using bisphosphonates and Interleukin 2. Unfortunately, many current stimulation protocols are based on the use of xenogenic materials and other potentially hazardous supplements, which conflicts with basic principles of Good Manufacturing Practice (GMP). Adherence to the concept and current guidelines of GMP is state of the art for production of Advanced Therapy Medicinal Products (ATMP) like cell therapeutics and a necessity for clinical use under a regulatory perspective. In this study, we developed a new stimulation protocol that induces a marked increase of γδ T cell counts and allows for an easier transition from research to clinical applications with minimized regulatory workload. It reliably leads to a cell product with a purity of more than 90% γδ T cells and improved in vitro anti-tumor activity compared to our previous standard procedure. Furthermore, by investigating correlations between properties of unstimulated γδ T cells and proliferation rate as well as degranulation ability of stimulated γδ T cells, we can draw conclusions about suitable donors. Finally, we examined if expansion can be improved by pulsing zoledronate and/or using Interleukin 15 with or without Interleukin 2. Significant improvements can be achieved with respect to intrinsic and antibody-dependent cell-mediated cytotoxicity. Our results demonstrate that the stimulation protocol presented here leads to an improved γδ T cell product for future clinical applications.

Wound Management, Including the Use of an Extracellular Matrix Powder, in a Blue-Tongued Skink (Tiliqua scincoides)

A 10-year-old intact male, blue-tongued skink (Tiliqua scincoides) presented with large dorsal wounds penetrating deep into the coelomic cavity. After initial debridement, decontamination, and bandaging, a powdered form of porcine extracellular matrix (ECM) was applied to the wound and covered with a non-adhesive bandage. Three days following application, a thin crust formed over the wound bed. Within seven days of application, reduced wound depth and granulation tissue were present, at which point the crust was removed, and a second application of ECM powder was made. Eleven days after initial application, approximately 50% of the wound was covered by thin epithelial tissue extending from the wound margins. Fifteen days after the first application, 100% of the wound appeared to be covered with thin epithelial tissue with marginal crusting. The patient was discharged 24 days post presentation (15 days post initial ECM application) with no further treatment. The owner was instructed to remove the bandage seven days post discharge. Twenty-four days after the initial application, the owner reported a full shed with complete epithelization and no further crusting. The patient was followed up 31 days after the initial presentation and was assessed as recovered from the initial wounds. To the author's knowledge, this is the first reported use of an ECM powder, or a xenogeneic material used to treat a traumatic wound in a Tiliqua.

Evaluation of Biocompatibility of New Osteoplastic Xenomaterials Containing Zoledronic Acid and Strontium Ranelate

Background. The problem of improving the functional characteristics of implanted devices and materials used in traumatology and orthopedics is a topical issue.
 Aim of the study to study biocompatibility of bovine bone matrix xenomaterials modified by zoledronic acid and strontium ranelate when implanted into the bone defect cavity.
 Methods. The study was performed on 24 male rabbits of the Soviet Chinchilla breed. Test blocks of bone matrix were implanted into the cavity of bone defects of the femur. Group 1 animals (n = 8, control group) were implanted with bone xenogenic material (Bio-Ost osteoplastic matrix). Group 2 animals (n = 8) were implanted with bone xenogenic material impregnated with zoledronic acid. Group 3 animals (n = 8) were implanted with bone xenogeneic material impregnated with strontium ranelate. Supercritical fluid extraction technology was used to purify the material and impregnate it with zoledronic acid and strontium ranelate. Radiological, pathomorphological, histological and laboratory (hematology and blood biochemistry) diagnostic methods were used to assess biocompatibility. Follow-up period was 182 days after implantation.
 Results. It was found out that on the 182nd day after implantation the median area of the newly-formed bone tissue in the defect modeling area in Group 1 was 79%, in Group 2 0%, in Group 3 67%. In Group 2 the maximum area by this period was filled with connective tissue 77%. Median relative area of implanted material fragments in Group 1 was 4%, in Group 2 23%, in Group 3 15%. No infection or material rejection was observed in animals of all groups. There were no signs of intoxication or prolonged systemic inflammatory reaction. Laboratory parameters did not change significantly over time. One animal in each group experienced one-time increase in C-reactive protein level against the background of leukocytosis. Two animals in Group 1 had a slight migration of implanted material under the skin, one animal developed arthritis of the knee joint.
 Conclusion. Osteoplastic materials based on bovine bone xenomatrix and filled with zoledronic acid and strontium ranelate have acceptable values of biocompatibility including their safety profile.

Guided Tissue Regeneration in Class IV External Cervical Resorption: A Case Report

External cervical resorption (ECR) is a type of dental resorption that originates from the loss of the cementum's protective layer. The direct exposure of dentin to the periodontal ligament may lead to the invasion of clastic cells through an entry point on the external root surface into the dentinal tissue, causing resorption. Depending on the extension of ECR, different treatments are proposed. Although the literature presents distinct materials and methods for restoring ECR areas, an existing gap is related to care in the treatment of the supporting periodontal tissue. Guided tissue regeneration (GTR)/guided bone regeneration includes the stimulation of bone formation in bone defects using different types of membranes (resorbable and nonresorbable), regardless of its association with bone substitutes or grafts. Despite the benefits of guided bone regeneration, the application of this method in cases of ECR is still under-explored in the literature. Thus, the present case report uses GTR with xenogenic material and polydioxanone membrane in a case of class IV ECR. The success of the present case is related to the correct diagnosis and treatment plan. Complete debridement of resorption areas and restoration with biodentine were effective in tooth repair. GTR contributed to the stabilization of supporting periodontal tissues. The association of the xenogeneic bone graft with the polydioxanone membrane proved to be a viable option for restoring the health of the periodontium.

Neural Differentiation of Induced Pluripotent Stem Cells for a Xenogeneic Material-Free 3D Neurological Disease Model Neurulation from Pluripotent Cells Using a Human Hydrogel.

Alzheimer's Disease (AD) is characterized by synapse and neuronal loss and the accumulation of neurofibrillary tangles and Amyloid β plaques. Despite significant research efforts to understand the late stages of the disease, its etiology remains largely unknown. This is in part because of the imprecise AD models in current use. In addition, little attention has been paid to neural stem cells (NSC), which are the cells responsible for the development and maintenance of brain tissue during an individual's lifespan. Thus, an in vitro 3D human brain tissue model using induced pluripotent stem (iPS) cell-derived neural cells in human physiological conditions may be an excellent alternative to standard models to investigate AD pathology. Following the differentiation process mimicking development, iPS cells can be turned into NSCs and, ultimately, neural cells. During differentiation, the traditionally used xenogeneic products may alter the cells' physiology and prevent accurate disease pathology modeling. Hence, establishing a xenogeneic material-free cell culture and differentiation protocol is essential. This study investigated the differentiation of iPS cells to neural cells using a novel extracellular matrix derived from human platelet lysates (PL Matrix). We compared the stemness properties and differentiation efficacies of iPS cells in a PL matrix against those in a conventional 3D scaffold made of an oncogenic murine-matrix. Using well-defined conditions without xenogeneic material, we successfully expanded and differentiated iPS cells into NSCs via dual-SMAD inhibition, which regulates the BMP and TGF signaling cascades in a manner closer to human conditions. This in vitro, 3D, xenogeneic-free scaffold will enhance the quality of disease modeling for neurodegenerative disease research, and the knowledge produced could be used in developing more effective translational medicine.

Soft-Tissue Augmentation around Dental Implants with a Connective Tissue Graft (CTG) and Xenogeneic Collagen Matrix (CMX)-5-Year Follow-Up.

Proper horizontal and vertical thickness of the gingival connective tissue has been proven to be one of the success criteria in dental implant and reconstructive surgery. When thin tissue is found, gingiva augmentation methods can be used to increase the quality and volume of the tissue. Many methods have been described, among them pedicle soft-tissue flaps or autogenic tissue grafts. As an alternative to patients' own tissue, xenogenic materials can be used for grafting. The fundamental issue is to choose a material that will ensure the maximum therapeutic effect, while also minimizing the negative influence on the patient's health. The aim of this study was to compare gingival augmentation procedures using a palatal connective tissue graft (CTG) and an xenogenic soft-tissue substitute, Geistlich Mucograft (xenogeneic collagen matrix; CMX), and assess whether the timing of the graft surgery influences the clinical outcomes. The original study was a randomized control trial with a total of 75 implants placed. The patients received the soft-tissue thickening 3 months before the implant placement or 3 months after the implant placement (depending on the group). A connective tissue graft (CTG) or Geistlich Mucograft were used (depending on the group). For both the CTG and Geistlich Mucograft, better clinical outcomes were observed for maintaining the alveolar bone level and the thickness of the attached gingiva compared to the control group with no gingival augmentation. The Geistlich Mucograft showed good clinical performance in comparison to the control. Soft-tissue augmentation with the CTG before the implant placement was found to be most efficient method in terms of a stable increase of the tissue thickness since, throughout the entire observation period, the greatest increase of 1.035 mm (SD = 0.73 mm) in thickness was observed. Statistically important differences in the tissue thickness baseline compared after 5 years were observed for groups G1 vs. G2b (no augmentation vs. CTG before), G1 vs. G3b (no augmentation vs. CTG after) and for groups G2b vs. G3a (CTG before vs. CMX after).

Perpendicular implantation of porcine trachea extracellular matrix for enhanced xenogeneic scaffold surface epithelialization in a canine model.

The availability of clinically applied medical materials in thoracic surgery remains insufficient, especially materials for treating tracheal defects. Herein, the potential of porcine extracellular matrix (P-ECM) as a new airway reconstruction material was explored by xenotransplanting it into a canine trachea. P-ECM was first transplanted into the buttocks of Narc Beagle dogs (n = 3) and its overall immuno-induced effects were evaluated. Subsequently, nine dogs underwent surgery to create a tracheal defect that was 1 × 2 cm. In group A, the P-ECM was implanted parallel to the tracheal axis (n = 3), whereas in group B the P-ECM was implanted perpendicular to the tracheal axis (n = 6). The grafts were periodically observed by bronchoscopy and evaluated postoperatively at 1 and 3 months through macroscopic and microscopic examinations. Immunosuppressants were not administered. Statistical evaluation was performed for Bronchoscopic stenosis rate, graft epithelialization rate, shrinkage rate and ECM live-implantation rate. No sign of P-ECM rejection was observed after its implantation in the buttocks. Bronchoscopic findings showed no improvement concerning stenosis in group A until 3 months after surgery; epithelialization of the graft site was not evident, and the ECM site appeared scarred and faded. In contrast, stenosis gradually improved in group B, with continuous epithelium within the host tissues and P-ECM. Histologically, the graft site contracted longitudinally and no epithelialization was observed in group A, whereas full epithelialization was observed on the P-ECM in group B. No sign of cartilage regeneration was confirmed in both groups. No statistically significant differences were found in bronchoscopic stenosis rate, shrinkage rate and ECM live-implantation rate, but graft epithelialization rate showed a statistically significant difference (G-A; sporadic (25%) 3, vs. G-B; full covered (100%) 3; p = 0.047). P-ECM can support full re-epithelialization without chondrocyte regeneration, with perpendicular implantation facilitating epithelialization of the ECM. Our results showed that our decellularized tracheal matrix holds clinical potential as a biological xenogeneic material for airway defect repair.

Changes in Alveolar Bone Width Following Immediate Implant and Fresh Socket Preservation with Xenogeneic Gap-Filling Material Versus Guided Tissue Healing with Anatomical Tooth-Shaped Caps: A 3-Year Retrospective Case-Control Study.

This study aimed to calculate the 3-year dimensional change in crestal bone width when dental implants placed in postextraction sockets underwent two alternative techniques for alveolar preservation. Fresh sockets that had undergone immediate implant placement were categorized into one of two groups depending on the procedure type. For the xenogeneic biomaterial grafted (BG) group, the gaps between the metallic implant surfaces and the bony walls were filled with corticocancellous porcine bone; in the anatomical cap group, in which patients were treated with guided tissue healing (GTH), cross-linkable acrylic resin caps were immediately screwed on the implants. Absolute measurements of the alveolar width were performed on 3D images acquired before tooth extraction (thereby ensuring correct surgical treatment) and 3 years after surgery. Nonparametric statistics were performed, with the level of significance set at 1%. The results of 46 implants (placed in 36 patients) were analyzed, and 100% survival rates were reported for both groups at 3 years postsurgery. Minor swelling of treated areas was observed the first few days of healing, but neither mucositides, dehiscence events, nor suppurations occurred. At 3 years postsurgery, loss in alveolar ridge width was higher for the BG group (-1.1 ± 0.6 mm) than for the GTH group (0.0 ± 0.3 mm); moreover, these changes were significantly different (P < .0001). This clinical and radiographic data analysis suggests that the implant sites that received a xenogeneic filling material were less effective in maintaining the preoperative alveolar bone width than sites that underwent GTH with immediate implants and anatomical tooth-shaped caps.

Alveolar ridge preservation: Complications and cost-effectiveness.

Alveolar ridge preservation is routinely indicated in clinical practice with the purpose of attenuating postextraction ridge atrophy. Over the past two decades numerous clinical studies and reviews on this topic have populated the literature. In recent years the focus has primarily been on analyzing efficacy outcomes pertaining to postextraction dimensional changes, whereas other relevant facets of alveolar ridge preservation therapy have remained unexplored. With this premise, we carried out a comprehensive evidence-based assessment of the complications associated with different modalities of alveolar ridge preservation and modeled the cost-effectiveness of different therapeutic modalities as a function of changes in ridge width and height. We conclude that, among allogeneic and xenogeneic bone graft materials, increased expenditure does not translate into increased effectiveness of alveolar ridge preservation therapy. On the other hand, a significant association between expenditure on a barrier membrane and reduced horizontal and vertical ridge resorption was observed, though only to a certain degree, beyond which the return on investment was significantly diminished.

Mid-term performance of decellularized equine pericardium in congenital heart surgery.

The aim was to report mid-term performance of decellularized equine pericardium used for repair of various congenital heart defects in the pediatric population. A retrospective review of all patients undergoing patch implantation between 2016 - 2020 was performed. Patch quality, surgical handling, hemostasis and early patch-related complications were studied on all patients. Mid-term performance was observed in patients with ≥12 months follow-up and intact patch at discharge (without reoperation/stent implantation). A total of 201 patients with median age of 2.5 years [interquartile range (IQR): 0.6-6.5] underwent 207 procedures at 314 implant locations. The patch was used in following numbers/locations: 171 for pulmonary artery (PA) augmentation, 36 for aortic repair, 35 for septal defect closure, 22 for valvular repair and 50 at other locations. Early/30-day mortality was 6.5%. Early patch-related reoperations/stent implantations occurred in 28 locations (8.9%). No patch-related complications were noted except for bleeding from implant site in three locations (1%). Follow-up ≥ 12 months was available for 132 patients/200 locations. During a median follow-up of 29.7 months [IQR: 20.7-38.3], 53 patch-related reoperations/catheter reinterventions occurred (26.5%) with the majority in PA position (88.7%, 47/53). Overall 12- and 24-months freedom from patch-related reoperation/catheter reintervention per location was 91.5% (95% CI: 86.7%-94.6%) and 85.2% (95% CI: 78.9%-89.6%) respectively. Decellularized equine pericardium used for repair of various congenital heart defects showed acceptable mid-term performance. Reoperation/reintervention rates were in a range as observed with other xenogeneic materials previously reported articles, occurring most frequently after PA augmentation.

A compositional analysis of native and decellularized porcine nasal septum cartilage.

Decellularization of porcine septum cartilage is necessary for its application as xenogenic replacement material. The aim of this study was to investigate spatial differences of structure and composition in the whole native and decellularized porcine nasal septum. Subsequently, the results shall be compared with studies of human nasal septum. Ten porcine nasal septa were divided into six regions from caudal to cephalic and four regions from dorsal to ventral to create a grid of 24 approximately equal segments. All segments of five septal cartilages were decellularized separately by a wet chemical multistep procedure. The segments were analyzed to determine quantitative amounts of total collagen, chondrocytes, and sulfated glycosaminoglycans (sGAG). The distribution of cell number showed no significant differences between the individual regions. For the distribution of collagen and sGAG, no significant differences could be identified from caudal to cephalic, both in native and decellularized tissue. From dorsal to ventral, native and decellularized nasal septum showed significant differences between individual regions. In native septum, linear regression analysis indicated a decreasing collagen and an increasing sGAG content from dorsal to ventral. After decellularization, an increasing collagen and a decreasing sGAG content was detected. The results of this study showed slightly but significant differences in the distribution of collagen and sGAG from dorsal to ventral. From caudal to cephalic, no differences could be observed. Compared to human, nasal septum differences in cell, collagen, and sGAG content were detected. Despite this, human and porcine nasal septum showed similar distributions and a consistently inverse linearity of collagen and sGAG content. Nevertheless, the midcaudal and midcephalic regions showed the highest porosity and a high stability and thus offer the best conditions for the revitalization of porcine tissue by human cells.

In Vivo Analysis of the Regeneration Capacity and Immune Response to Xenogeneic and Synthetic Bone Substitute Materials.

Although various studies have investigated differences in the tissue reaction pattern to synthetic and xenogeneic bone substitute materials (BSMs), a lack of knowledge exists regarding the classification of both materials based on the DIN ISO 10993-6 scoring system, as well as the histomorphometrical measurement of macrophage subtypes within their implantation beds. Thus, the present study was conducted to analyze in vivo responses to both xenogeneic and synthetic bone substitute granules. A standardized calvaria implantation model in Wistar rats, in combination with established scoring, histological, histopathological, and histomorphometrical methods, was conducted to analyze the influence of both biomaterials on bone regeneration and the immune response. The results showed that the application of the synthetic BSM maxresorb® induced a higher pro-inflammatory tissue response, while the xenogeneic BSM cerabone® induced a higher anti-inflammatory reaction. Additionally, comparable bone regeneration amounts were found in both study groups. Histopathological scoring revealed that the synthetic BSM exhibited non-irritant scores at all timepoints using the xenogeneic BSM as control. Overall, the results demonstrated the biocompatibility of synthetic BSM maxresorb® and support the conclusion that this material class is a suitable alternative to natural BSM, such as the analyzed xenogeneic material cerabone®, for a broad range of indications.

Доклиническая оценка эффективности и безопасности нового костнопластического материала ксеногенного происхождения, содержащего в своем объеме ванкомицин и меропенем

Bone xenomatrix is an available material for plasty due to its availability and possible significant modification. The purpose was comparative evaluation of the efficacy and safety of xenogenic bone graft material impregnated with antibiotics, vancomycin or meropenem, in an experiment on a model of long bone defect healing in rabbits. Methods The study was performed on 28 male rabbits aged from 8 months to 1.2 years. All animals were modeled with a cavity defect of the right and left distal femoral metaphysis measuring 4 × 4 × 6 mm. Bone matrix blocks of the same size were implanted into the defect cavity. Animals of group 1 (n = 8, control) were implanted with a free “clean” bone block. Animals of group 2 (n = 10) with a bone block saturated with vancomycin. Animals of group 3 (n = 10) with a bone block impregnated with meropenem. To assess the effectiveness and safety of the material, clinical, radiological, pathomorphological, histological, and laboratory methods were used. Results X-ray signs of substitution of the studied materials in the defect in animals of group 1 were noted by 182 days, in group 2 – by 84 days, in group 3 – about 182 days. In each group, there was a complication, arthrosis of the knee joint (one animal in each group). According to the histological study, it was found that in groups 2 and 3, a complete elimination of xenomaterial in the middle part of the defect and its replacement with trabecular bone was noted by 182 days after implantation. The severity of irritating action of the materials in the animals of groups 2 and 3 did not exceed the control value. The laboratory blood tests in the animals of groups 2 and 3 also did not reveal significant differences with group 1. Conclusion The developed osteoplastic materials based on bovine bone xenomatrix, impregnated with vancomycin or meropenem, have acceptable safety and efficacy characteristics.

Influence of Xenogeneic and Alloplastic Carriers for Bone Augmentation on Human Unrestricted Somatic Stem Cells.

Alloplastic and xenogeneic bone grafting materials are frequently used for bone augmentation. The effect of these materials on precursor cells for bone augmentation is yet to be determined. The aim of this study was to ascertain, in vitro, how augmentation materials influence the growth rates and viability of human unrestricted somatic stem cells. The biocompatibility of two xenogeneic and one alloplastic bone graft was tested using human unrestricted somatic stem cells (USSCs). Proliferation, growth, survival and attachment of unrestricted somatic stem cells were monitored after 24 h, 48 h and 7 days. Furthermore, cell shape and morphology were evaluated by SEM. Scaffolds were assessed for their physical properties by Micro-CT imaging. USSCs showed distinct proliferation on the different carriers. Greatest proliferation was observed on the xenogeneic carriers along with improved viability of the cells. Pore sizes of the scaffolds varied significantly, with the xenogeneic materials providing greater pore sizes than the synthetic inorganic material. Unrestricted somatic stem cells in combination with a bovine collagenous bone block seem to be very compatible. A scaffold’s surface morphology, pore size and bioactive characteristics influence the proliferation, attachment and viability of USSCs.

Histologic Evaluation of the Effect of Mecsina Hemostopper on Bone Regeneration for Critical-Size Defects.

Acceleration of the bone healing period and/or increasing the quality of newly formed bone still have great importance in the field of oral and maxillofacial surgery. The aim of this study was to evaluate the effect of isolated liquid Mecsina (herbal extract) and its combination with xenogeneic graft material (bovine bone graft) on bone regeneration. Full-thickness critical-size defects with 10-mm diameter and 2-mm depth were created on the calvarial bone region in 28 Sprague Dawley male rats. Four groups were generated: Mecsina Hemostopper, Mecsina Hemostopper + graft group, only graft group, and empty control group. On the 28th day following surgery, all animals were sacrificed. The calvarial samples were evaluated both histopathologically and histomorphometrically. According to the histopathologic evaluation result, vascular proliferation was significantly higher in the groups in which Mecsina Hemostopper was used as a single material or in combination with graft material (P < .05). Histomorphometric evaluation showed that trabecular and osteoid thickness were significantly higher in all Mecsina application groups (P < .05). Mecsina Hemostopper was found to be an effective agent in increasing cell proliferation and providing more qualified bone formation. The combination of Mecsina and xenogeneic bone graft was found to be one of the most effective augmentation options for critical-size defects in rats. Mecsina Hemostopper could be used to get more qualified bone formation clinically, but more clinical research is needed in the future.

EVALUATION OF THE EFFICIENCY OF SINUS LIFTING TECHNIQUES

Right after teeth extraction in posterior regions, there is a following process that consists of physiological resorption and nonfunctional atrophy of the remained alveolar bone ridge. That also impacts the quality on the quality and quantity of the remained bone tissue, what later makes the implant incorporation and the prosthetic restoration much harder and complicated than usual it is. In the posterior region of the upper jaw additional complication of the prosthetic restoration process causes the existing of paranasal sinus that is located right in the body of the upper jaw maxilla. It’s post extraction pneumatization reduces the height of bone tissue what causes difficulties in dental implants placement. The aim of this survey is to evaluate the clinical outcome and the efficiency of the most often used sinus lifting techniques. Were analyzed totally 78 published studies that were done in the last 12 years. The study is made on narrative review of published articles that were investigating the related subject. Research was done by using the most common data bases: NCBI (US National Library of Medicine), Emedicine, PubMEd, Webmd. By using the open method for sinus lifting there needs to be formed lateral window in the bone tissue first by elevating the mucoperiosteal flap on the vestibular surface of the maxillary alveolar ridge and after that creating iatrogenic fenestration on the cortical lamina without perforating the sinus membrane. After the sinus membrane is being separated, the following step is augmentation. For this step are used four different types of bone substituent: autogenous, allogeneic, xenogeneic bone graft and synthetic alloplastic materials. The closed method for sinus lifting is performed after previous created place for the future implant in the residual alveolar bone ridge in the maxilla, after that with special instruments a perforation is being made in the bone floor of the maxillary sinus and carefully elevating the sinus membrane up for a few millimeters. In the created space a bone graft material is being placed and at the same time a dental implant is being applied. From the gathered results, both of the techniques are considered to be effective, in all of the followed cases the implant placements were successful with high rate of postoperative osseointegration, the healing period was without complications and also successful. There was no prosthetic failure in any case. From this survey the final conclusion is that both of the techniques are successful when it comes to sinus lifting. Very important is to have a qualitative imaging like computed tomography or roentgen before placing the implants to be able to estimate the bone volume and height. If the residual bone height is less than 5 mm the survival rate of the future implants is not guaranteed.

Hyaluronic Acid with Bone Substitutes Enhance Angiogenesis In Vivo.

Introduction: The effective induction of angiogenesis is directly related to the success of bone-substitute materials (BSM) for maxillofacial osseous regeneration. Therefore, the addition of pro-angiogenic properties to a commercially available bovine bone-substitute material in combination with hyaluronic acid (BSM+) was compared to the same bone-substitute material without hyaluronic acid (BSM) in an in-vivo model. Materials and Methods: BSM+ and BSM were incubated for six days on the chorioallantoic membrane (CAM) of fertilized chicken eggs. Microscopically, the number of vessels and branching points, the vessel area and vessel length were evaluated. Subsequently, the total vessel area and brightness integration were assessed after immunohistochemical staining (H&E, alphaSMA). Results: In the BSM+ group, a significantly higher number of vessels (p < 0.001), branching points (p = 0.001), total vessel area (p < 0.001) as well as vessel length (p = 0.001) were found in comparison to the BSM group without hyaluronic acid. Immunohistochemically, a significantly increased total vessel area (p < 0.001 for H&E, p = 0.037 for alphaSMA) and brightness integration (p = 0.047) for BSM+ in comparison to the native material were seen. Conclusions: The combination of a xenogenic bone-substitute material with hyaluronic acid significantly induced angiogenesis in vivo. This might lead to a faster integration and an improved healing in clinical situations.

Efficacy of concentrated growth factor versus collagen membrane in reconstructive surgical therapy of peri-implantitis: 3-year results of a randomized clinical trial

ObjectivesTo compare the 3-year clinical and radiographic outcomes of two different reconstructive surgical management of peri-implantitis using a bone substitute in combination with either concentrated growth factor (CGF) or collagen membrane (CM).Material and methodsFifty-one patients who had at least one implant presenting peri-implantitis with an intrabony defect were filled with a xenogenic bone grafting material and covered either CGF or CM. Clinical and radiographic assessments were carried out at baseline and postoperative years 1 and 3. Three different composite outcomes were defined to evaluate treatment success at a 3-year follow-up. The effects of possible prognostic indicators on treatment success were identified by using multilevel regression analysis.ResultsThe changes in probing depth (PD) and radiographic vertical defect depth (VDD) between baseline and year 1 and baseline and year 3 presented significantly greater decreases for the CM group in comparison with the CGF group (p < 0.05). No significant differences between the two treatment modalities were demonstrated regarding treatment success outcomes. History of periodontitis, VDD at baseline, and the number of intrabony defect walls revealed significant impacts on treatment success (p = 0.033; OR = 3.50, p = 0.039; OR = 0.975, and p = 0.024; OR = 7.0 and p = 0.019;OR = 6.0, respectively).ConclusionsCM in combination with a bone substitute seems to have slightly better outcomes compared to the CGF membranes in reconstructive surgical therapy of peri-implantitis. The history of periodontitis, baseline VDD, and peri-implant bone defect configuration could be possible predictors influencing treatment success.Trial registrationClinicalTrials.gov NCT04769609.Clinical relevanceFor the reconstruction of peri-implant bone defects, using a bone substitute in combination with a collagen membrane may show more favorable outcomes.

Histological justification of the application of materials based on biomodified hyaluronic acid in combination with xenogenic osteoplastic material for maxillary alveolar bone augmentation before dental implantation

The objective of the present study was the comparative evaluation of the effectiveness of using the composition of xenogenic osteoplastic material and materials based on biomodified hyaluronic acid for maxillary alveolar bone augmentation before dental implantation based on the results of histological investigations. The material for the study was bone tissue biopsies obtained with the use of a trephine at the stage of installation of the dental implants. The 4 micron sections prepared with a microtome were examined under different modes of light microscopy: bright field, dark field, phase contrast and polarization. The results of the study gave evidence of the formation of the endogenous bone tissue instead of the osteoplastic material in both the experimental and the control groups of the patients. Using of the xenogenic osteoplastic material in combination with preparations of biomodified hyaluronic acid gave the best results during sinus lift operation, since in these cases the bone of the most mature structure was formed, and in most cases there were no fragments of the implanted osteoplastic material. Nevertheless, the quality of the bone regenerate made it possible to install dental implants 6 months after the sinus lift in all groups.

Eosinophilic meningitis following suboccipital craniotomy without bovine dural graft: illustrative case.

BACKGROUNDEosinophilic meningitis is a rare known complication after brain surgery associated with duraplasty using artificial bovine graft. However, eosinophilic meningitis after craniotomy without bovine dural graft has not been reported.OBSERVATIONSA 48-year-old female presented with lateral medullary infarction caused by a vertebral artery dissecting aneurysm incorporating the posterior inferior cerebellar artery (PICA). The authors performed occipital artery–PICA anastomosis and repaired the dura by primary suture without bovine graft. Thereafter, endovascular internal trapping using coils was conducted. Severe headache developed at postoperative day 17, and the patient was diagnosed with eosinophilic meningitis. After administration of a high-dose corticosteroid for 2 weeks, her symptoms and laboratory findings were improved.LESSONSPostoperative eosinophilic meningitis is rarely related to craniotomy without using bovine graft. Neurosurgeons should consider the possibility of eosinophilic meningitis after craniotomy without a xenogeneic dural material.