Platelet rich fibrin as a bioactive matrix with proosteogenic and proangiogenic properties on human healthy primary cells in vitro.

Blood concentrates like platelet rich fibrin (PRF) have been established as a potential autologous source of cells and growth factors with regenerative properties in the field of dentistry and regenerative medicine. To further analyze the effect of PRF on bone tissue regeneration, this study investigated the influence of liquid PRF matrices on human healthy primary osteoblasts (pOB) and co-cultures composed of pOB and human dermal vascular endothelial cells (HDMEC) as in vitro model for bone tissue regeneration. Special attention was paid to the PRF mediated influence on osteoblastic differentiation and angiogenesis. Based on the low-speed centrifugation concept, cells were treated indirectly with PRF prepared with a low (44 g) and high relative centrifugal force (710 g) before the PRF mediated effect on osteoblast proliferation and differentiation was assessed via gene and protein expression analyses and immunofluorescence. The results revealed a PRF-mediated positive effect on osteogenic proliferation and differentiation accompanied by increased concentration of osteogenic growth factors and upregulated expression of osteogenic differentiation factors. Furthermore, it could be shown that PRF treatment resulted in an increased formation of angiogenic structures in a bone tissue mimic co-culture of endothelial cells and osteoblasts induced by the PRF mediated increased release of proangiogenic growth factors. The effects on osteogenic proliferation, differentiation and vascularization were more evident when low RCF PRF was applied to the cells. In conclusion, PRF possess proosteogenic, potentially osteoconductive as well as proangiogenic properties, making it a beneficial tool for bone tissue regeneration.

What is the context?The treatment of bone defects is still a challenge in the field of regenerative medicine. In this context, researchers and clinicians are continuously focusing on developing new therapeutic strategies like the use of autologous blood concentrates like Platelet rich fibrin (PRF) to improve regeneration by directly delivering wound healing promoting cells and growth factors to the defect side in order to restore the structure and functional integrity of damaged hard tissue in combination with adequate tissue regeneration.What is new?Focus of the present in vitro study was to further evaluate the potential of PRF paying particular attention to the PRF-mediated effect on osteogenic differentiation and angiogenesis of human primary osteoblasts as well as on a more complex tissue like co-culture consisting of osteoblasts and microvascular endothelial cells. We could demonstrate that PRF is able to support and affect a variety of processes involved in bone tissue regeneration including osteogenic proliferation, osteogenic differentiation as well as angiogenic structure formation.Treatment of PRF resulted in:- increased cell viability*- higher expression of osteogenic differentiation factors*- higher release of osteogenic growth factors*- increased formation of microvessel-like structures*(*compared to untreated control)What is the impact?PRF represents a beneficial autologous tool for regenerative purposes combining proosteogenic and proangiogenic properties. Therefore, PRF might be used for applications in versatile fields of medicine in the context of improving bone tissue regeneration.

Leukocytes within Autologous Blood Concentrates Have No Impact on the Growth and Proliferation of Human Primary Osteoblasts: An In Vitro Study.

Platelet-rich fibrin (PRF) is a widely used autologous blood concentrate in regenerative medicine. This study aimed to characterize the cellular composition and distribution of different PRF matrices generated by high (710 g) and low (44 g) relative centrifugal forces (RCFs) and to analyze their bioactivity on human primary osteoblasts (pOBs). PRF was separated into upper layer (UL) and buffy coat (BC) fractions, and their cellular contents were assessed using histological and immunohistochemical staining. The release of platelet-derived growth factor (PDGF) and transforming growth factor (TGF-ß) was quantified using an ELISA. Indirect PRF treatment on pOBs was performed to evaluate cell viability and morphology. A histological analysis revealed higher quantities of leukocytes and platelets in the low-RCF PRF. TGF-ß release was significantly higher in the low-RCF PRF compared to the high-RCF PRF. All PRF fractions promoted pOB proliferation regardless of the centrifugation protocol used. The low-RCF PRF showed higher TGF-ß levels than the high-RCF PRF. These findings contribute to understanding the cellular mechanisms of PRF and provide insights into optimizing PRF protocols for bone regeneration, advancing regenerative medicine, and improving patient outcomes.

Effectiveness of Oroantral Communication Closure Using Solid Platelet-Rich Fibrin Compared to a Conventional Treatment Approach: A Randomized Clinical Trial.

This study aimed to compare the effectiveness of platelet-rich fibrin clot (PRF) and conventional oroantral communication (OAC) repair techniques following tooth extractions from the maxilla. The study involved 22 patients, divided into 2 groups: a study group treated with PRF and a control group undergoing conventional OAC repair. The primary outcome measured was the effectiveness of OAC closure, with pain intensity and postoperative complications as secondary outcomes. Cone-beam computed tomography (CBCT) was used to evaluate post-extraction bone regeneration. Pain was assessed using the Visual Analogue Scale (VAS) on days 0, 1, 7, and 14 postoperatively. The results showed that the PRF group experienced a significant decrease in pain within the first 24 hours and after 7 days (P < .0001; P < .05). In contrast, complications were reported in 45.45% of patients in the conventional repair group and 18.18% in the A-PRF group. Three months postsurgery, CBCT revealed appreciable bone healing in both groups, with no significant difference (P > .05). In conclusion, the study suggests that A-PRF treatment for OACs resulted in fewer complications and quicker pain reduction than traditional repair methods, making it a promising alternative for managing OACs. However, future studies are needed to confirm these findings and establish the full therapeutic potential of PRF.

Hyperspectral Imaging Allows Evaluation of Free Flaps in Craniomaxillofacial Reconstruction.

INTRODUCTION: Treatment of extended defects after tumor resection in oral, maxillofacial, and facial surgery (craniomaxillofacial) is usually performed by free microvascular flaps. Evaluation of flap survival is crucial, especially in the first hours after insertion and connection. For flap evaluation various invasive and noninvasive methods have been developed. This retrospective clinical study examined the ability of a hyperspectral imaging (HSI) camera (Tivita, Diaspective Vision, Germany) to assess postoperative flap properties in comparison to established clinical parameters. MATERIALS AND METHODS: Thirteen patients with tumor resection and free flap reconstruction were included for camera analysis and another 10 patients as control group. For this purpose, at defined time intervals and under standardized conditions, recordings of transplants 3 to 100 hours postoperatively were performed. Images were used to examine oxygenation (StO 2 %), tissue hemoglobin index, tissue water index, near infrared range perfusion index of free flaps quantitatively and qualitatively. RESULTS: HSI provides values differing between patients observed with no intraindividual significant difference. After 24 hours a mean reduction of 16.77% for StO 2 %, 9.16% for tissue hemoglobin index and 8.46% was observed, going in line with no loss of flap was noted in the observation period. CONCLUSION: HSI is suitable as a noninvasive measure for the evaluation of free flaps in craniomaxillofacial surgery in case of stable imaging conditions with respect to light, surrounding and position of the camera. However, clinical measurements are still the method of choice.

Interaction of Telomere Length and Inflammatory Biomarkers Following Zirconia Implant Placement: A Case Series.

Zirconia implants have gained popularity for their aesthetic appeal and biocompatibility, making them a preferred choice for anterior teeth replacement. This study explores the interaction between telomere length and inflammatory biomarkers in seven cases of zirconia implant placement to gain insights into postoperative cellular aging, inflammatory responses, and long-term outcomes. Zirconia implants offer advantages over titanium implants, as they do not corrode or release metal ions, leading to potential inflammation and implant failure. Monitoring immune and inflammatory biomarkers is essential to assess inflammation initiation, severity, and progression. C-reactive protein (CRP) and pro-inflammatory cytokines, like interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), play crucial roles in host immune responses, while anti-inflammatory cytokines, including interleukin-10 (IL-10), regulate and dampen immune responses. Achieving a delicate balance between pro- and anti-inflammatory cytokines is vital for maintaining a healthy immune response and preventing chronic inflammatory conditions. Telomeres, protective structures present at chromosome ends, influence cellular aging and mitochondrial function. Shorter telomeres are associated with impaired mitochondrial function, increased oxidative stress, and cellular senescence, while longer telomeres are linked to reduced inflammation and improved immune function. Understanding these mechanisms is essential for addressing age-related conditions and promoting overall well-being. In this case series, we investigated the interaction between telomere length and inflammatory biomarkers in patients who received zirconia dental implants. The study aims to improve our understanding of postoperative cellular aging, inflammatory responses, and the biocompatibility of zirconia implants, potentially leading to improved treatment protocols and patient outcomes. This innovative assessment of telomere length and inflammatory biomarkers in the context of zirconia implants provides novel insights into the field of dental implantology. By exploring the effects of zirconia implants on cellular health and inflammation, this study contributes to advancements in implant technology and patient care.

Image Fusion Improves Interdisciplinary Communication in the Treatment of Head and Neck Cancer.

INTRODUCTION: The diagnosis and therapy of oral squamous cell carcinoma (Osee) in Germany is according to guidelines and relies on interdisciplinary board meetings. Standard examination techniques are computed tomography (CT) and magnet resonance imaging (MRI). These technologies are used as objective tools for serial presentation in an oncologic board meeting. The presentation of multiple series at different time points can be time consuming and might not often depict a patients case clearly for all involved disciplinaries. A conclusive image fusion could improve the communication. Thus, this study aims to introduce a novel idea of image fusion into the field of craniomaxillofacial surgery in order to ease understanding and improve therapy in complex Osee patients' cases. MATERIALS AND METHODS: Three key data sets of a patient with OSCC at the right tongue have been merged by image fusion of 3 MRi of head and neck with 3 CT thorax and abdomen using Syngo via (Siemens). Fused images were used as at a glance picture for presenting and discussion a patients case. Focus was on presenting a case of a primary manifestation of OSCC with the potential of a local relapse and distant metastases in an interdisciplinary oncol-ogic board meeting. RESULTS: Image fusion enabled to visualize the primary tumor, local relapse as well as distant pulmonary metastasis and within the suprarenal gland, which have been occurred in a linear time line of 13 months. DISCUSSION: Image fusion of different modalities that is CT and MRi, which were gathered at different time points, presents a new approach within the field of craniomaxillofacial surgery and helped to understand cancer localization and relapse at 1 glance. This new approach will enable a compact data set of patients oncological history as a more decisive tool for all involved disciplinaries. CONCLUSIONS: Image fusion might have the potential to become a standard approach in order to ease multiple therapists to make therapy decisions in oncologic board meetings on basis of current three-dimensional ready CT imaging and MRI.

[Pre-treatment dysphagia in head-and-neck cancer patients]. / Prätherapeutische Dysphagie bei Kopf-Hals-Tumor-Patienten.

BACKGROUND: The swallowing and nutritional status of head-and-neck cancer patients after oncological therapy have been extensively researched. However, the same topics are seldom scrutinized before the onset of oncological therapy, although they can influence treatment success in the long term. OBJECTIVE: This study focusses on a systematic assessment of swallowing function and nutritional status in head-and-neck cancer patients prior to oncological therapy. MATERIALS AND METHODS: In 102 patients, penetration/aspiration (PA scale), limitations of oral intake (Functional Oral Intake Scale, FOIS), and the need for further intervention (NFI) were endoscopically assessed to objectively quantify swallowing function. The subjective evaluation of swallowing function was carried out with the gEAT-10 (German EAT-10) questionnaire, nutritional status was assessed by body mass index (BMI). Possible impact factors for swallowing function and BMI were analyzed by univariate and multivariate methods. RESULTS: PAS, FOIS, and NFI values were abnormal in ≤ 15% of patients. BMI was more often too high than too low. Objectively assessed swallowing functions depended predominantly on tumor stage and showed moderate correlations with gEAT-10. The latter mostly yielded a "fail" result. The nutritional status depended on the patients' biological sex and NFI. CONCLUSION: In the pre-treatment setting, neither dysphagia nor malnutrition were found in most patients. Impaired swallowing was associated with higher tumor stages, malnutrition with female sex and NFI. A systematic pre-treatment assessment of swallowing and nutritional status in head-and-neck cancer patients appears necessary for modern oncological therapy and optimal patient outcome.

[Nutritional Risk Screening in head-and-neck cancer patients prior to oncological therapy]. / Screening auf Mangelernährung bei Kopf-Hals-Tumor-Patienten vor onkologischer Therapie.

OBJECTIVE: Head-and-neck cancer patients run a high risk of peri- or post-treatment malnutrition that can severely affect the therapy outcome. However, little is known about malnutrition under the pre-treatment condition. Therefore, this study aimed to provide a systematic description of the pre-treatment nutritional status and risk of malnutrition in this population. MATERIAL AND METHODS: Before the onset of the oncological therapy, nutritional status of 102 head-and-neck cancer patients was assessed by body mass index (BMI), their risk of malnutrition by "Nutritional Risk Screening" (NRS). Tumour stage and site, patients' age and sex as well as oropharyngeal dysphagia were analysed as possible influence factors. The latter was quantified by the Flexible Endoscopic Evaluation of Swallowing (FEES). RESULTS: According to BMI, malnutrition (undernutrition) was found in 6% of patients, a risk of malnutrition (NRS) in 27% of patients, and oropharyngeal dysphagia in 15%. In a linear regression, only oropharyngeal dysphagia was identified as a significant influence factor for the risk of malnutrition (ß = 0.380/3.776; p < .001). CONCLUSIONS: Pre-treatment risk of malnutrition was found in a quarter of head-and-neck cancer patients. For the early identification of this risk and for the introduction of measures that would help to avoid it, a pre-treatment examination of swallowing functions and a systematic malnutrition screening by means of NRS are recommended.

[Post-operative prevalence of dysphagia in head-and-neck cancer patients in the acute care units]. / Postoperative Dysphagieprävalenz bei Kopf-Hals-Tumorpatienten im akutstationären Setting.

OBJECTIVE: Dysphagia constitutes a frequent post-operative functional impairment in head-and-neck cancer patients. This impairment can result in aspiration/penetration and limitations of oral intake. Therefore, often it requires a therapeutic intervention. In this study, prevalence of post-operative dysphagia and its associations with the tumour stage, localisation, patients' age, and biological sex were analysed for the inpatient treatment setting. MATERIAL AND METHODS: A total of 201 adult head-and-neck cancer patients (mean age 63 years) were analysed prospectively by FEES in two university hospitals in regard to their penetration/aspiration, limitations of oral intake, and need for therapeutic interventions directly after the operative tumour treatment. Additionally, the influence of the same patients' characteristics on these three parameters were analysed by means of univariate and multivariate statistical methods. RESULTS: Out of 201 patients, 66.7 % needed a therapeutic intervention because of their dysphagia, 57.2 % needed a nasogastral or PEG tube due to limitations of oral intake, 45.3 % had an aspiration. In the latter subgroup, 38.5 % had a silent aspiration. Higher tumour stage, patients' higher age and male sex were shown to be significant influence factors for dysphagia, tumour localisation showed only a marginally significant result. CONCLUSIONS: The study demonstrated a clinical importance and relevance of the consequent and systematic treatment of post-operative dysphagia in head-and-neck cancer patients in the acute care units as a constituent of a modern oncological therapy.

In vivo cellular reactions to different biomaterials-Physiological and pathological aspects and their consequences.

Biomaterials are widely used in guided bone regeneration (GBR) and guided tissue regeneration (GTR). After application, there is an interaction between the host immune system and the implanted biomaterial, leading to a biomaterial-specific cellular reaction. The present review focuses on cellular reactions to numerous biomaterials in vivo with consideration of different implantation models and microenvironments in different species, such as subcutaneous implantation in mice and rats, a muscle model in goats and a femur model in rabbits. Additionally, cellular reactions to different biomaterials in various clinical indications within the oro-maxillofacial surgical field were considered. Two types of cellular reactions were observed. There was a physiological reaction with the induction of only mononuclear cells and a pathological reaction with the induction of multinucleated giant cells (MNGCs). Attention was directed to the frequently observed MNGCs and consequences of their appearance within the implantation region. MNGCs have different subtypes. Therefore, the present review addresses the different morphological phenotypes observed within the biomaterial implantation bed and discusses the critical role of MNGCs, their subtypes and their precursors as well as comparing the characteristics and differences between biomaterial-related MNGCs and osteoclasts. Polymeric biomaterials that only induced mononuclear cells underwent integration and maintained their integrity, while polymeric biomaterials that induced MNGCs underwent disintegration with material breakdown and loss of integrity. Hence, there is a question regarding whether our attention should be directed to alternative biological concepts, in combination with biomaterials that induce a physiological mononuclear cellular reaction to optimize biomaterial-based tissue regeneration.

Autologous platelet-rich fibrin (PRF) augmentation as an add-on therapy in deep surgical site infections (dSSIs) after instrumented spinal surgery: preliminary results of a single institution case series.

BACKGROUND: Deep surgical site infections (dSSIs) after instrumented spinal surgery pose major therapeutic challenges. Standard treatment involves surgical debridement, wound drainage, and long-term antibiotic administration. Autologous platelet-rich fibrin (PRF) constitutes a biomaterial obtained from patients' own blood that contains leukocytes, chemokines and growth factors boosting cicatrization. Due to favorable results reported from other surgical disciplines such as dentistry, orthopedics, maxillofacial and plastic surgery using PRF, the authors hypothesized that PRF augmentation will promote wound healing in dSSIs. OBJECTIVE: To report our preliminary results on the safety and efficacy of autologous-PRF as an add-on therapy on a pilot case series of persistent dSSI after instrumented spinal surgery. METHODS: Among the 293 patients who underwent dorsal decompression and stabilization of the cervical, thoracic, and lumbar spine due to degenerative diseases in our department, 12 patients (4%) presented persisting dSSI after standard wound debridement and antibiotic treatment. PRF augmentation was used during a second surgical revision as an add-on therapy to standard debridement. In all cases, the wound was primarily closed without drains. RESULTS: Wound healing was completed between 14 and 21 days after the second surgical revision in all patients. At a median follow-up of 8 months (range: 6 to 18 months), no recurrence of dSSI nor complications were encountered in any case. CONCLUSIONS: Our preliminary results suggest that PRF augmentation in persistent dSSI after instrumented spinal surgery appears to be a safe and effective strategy to promote wound healing. Prospective controlled studies are required to define the efficiency of PRF more clearly in both treating and preventing dSSI.

Patterns of care, toxicity and outcome in the treatment of salivary gland carcinomas: long-term experience from a tertiary cancer center.

BACKGROUND: Salivary gland carcinomas (SGC) cover a heterogeneous group of malignancies with a lack of data of high-level evidence. METHODS: Clinical data of 127 patients treated for SGC at a university cancer center between 2002 and 2017 were analyzed retrospectively. The association of clinicopathological characteristics, treatment modalities, adverse events, and outcome was assessed. RESULTS: Patients received surgery (n = 65), surgery followed by (chemo-)radiotherapy (n = 56), or primary (chemo-)radiotherapy (n = 6). Injury to the cranial nerves or their branches was the most frequent surgical complication affecting 40 patients (33.1%). Ten year overall and progression-free survival rates were 73.2% and 65.4%, respectively. Parotid tumor site, advanced tumor, and positive nodal stage remained independent negative prognostic factors for overall survival, loco-regional and distant tumor control in multivariate analysis. CONCLUSIONS: Optimizing treatment strategies for SGC, depending on distinct clinicopathological factors, remains challenging due to the low incidence rates of the disease.

Multinucleated giant cells within the in vivo implantation bed of a collagen-based biomaterial determine its degradation pattern.

OBJECTIVES: The aim of the present study was to characterize the cellular reaction to a xenogeneic resorbable collagen membrane of porcine origin using a subcutaneous implantation model in Wistar rats over 30 days. MATERIALS AND METHODS: Ex vivo, liquid platelet-rich fibrin (PRF), a leukocyte and platelet-rich cell suspension, was used to evaluate the blood cell membrane interaction. The material was implanted subcutaneously in rats. Sham-operated rats without biomaterial displayed physiological wound healing (control group). Histological, immunohistological, and histomorphometric analyses were focused on the inflammatory pattern, vascularization rate, and degradation pattern. RESULTS: The membrane induced a large number of mononuclear cells over the observation period, including lymphocytes, macrophages, and fibroblasts. After 15 days, multinucleated giant cells (MNGCs) were observed on the biomaterial surface. Their number increased significantly, and they proceeded to the center of the biomaterial on day 30. These cells highly expressed CD-68, calcitonin receptor, and MMP-9, but not TRAP or integrin-ß3. Thus, the membrane lost its integrity and underwent disintegration as a consequence of the induction of MNGCs. The significant increase in MNGC number correlated with a high rate of vascularization, which was significantly higher than the control group. Physiological wound healing in the control group did not induce any MNGCs at any time point. Ex vivo blood cells from liquid-PRF did not penetrate the membrane. CONCLUSION: The present study suggests a potential role for MNGCs in biomaterial degradation and questions whether it is beneficial to accept them in clinically approved biomaterials or focus on biomaterials that induce only mononuclear cells. Thus, further studies are necessary to identify the function of biomaterial-induced MNGCs. CLINICAL RELEVANCE: Understanding the cellular reaction to biomaterials is essential to assess their suitability for specific clinical indications and outline the potential benefit of specific group of biomaterials in the respective clinical indications.

Patterns of Craniomaxillofacial Trauma After E-Scooter Accidents in Germany.

INTRODUCTION: E-Scooters are trending as an individual transport vehicle with electric drive in Germany. But there is less data about the frequency, demographic details and possible injuries and therapy needs in context with E-scooter accidents. Therefore, the primary aim of this study was to analyze the frequency and the characteristics of facial trauma as well as the consecutive hospitalization and management after injuries with E-scooters in a German clinic specialized in craniomaxillofacial surgery. MATERIALS AND METHODS: Retrospective data analysis of the hospital information system of patients admitted to central emergency unit driving e-scooters and injuries between June and December 2019. RESULTS: A total of 28 consecutive patients were admitted to the emergency care unit of a level one trauma center from June to December 2019. 85% had a minimum of two or more facial injuries. Most common were soft tissue injuries with 64% (n = 18), fractures with 54% (n = 15) and teeth injuries with 39% (n = 11). 82% percent of injuries were related with consumption of alcohol. DISCUSSION: The data show a variety of different injuries from teeth injury, wounds and facial fractures in varying degrees in a predominantly young and male cohort (mean age 33.57, 68% male) often associated with alcohol. As accidents happen especially at nighttime and on weekends personnel capacities should be provided. Still bicycle accidents and following injuries stay a major problem.

Biologization of Pcl-Mesh Using Platelet Rich Fibrin (Prf) Enhances Its Regenerative Potential In Vitro.

INTRODUCTION: Resorbable synthetic scaffolds are promising for different indications, especially in the context of bone regeneration. However, they require additional biological components to enhance their osteogenic potential. In addition to different cell types, autologous blood-derived matrices offer many advantages to enhance the regenerative capacity of biomaterials. The present study aimed to analyze whether biologization of a PCL-mesh coated using differently centrifuged Platelet rich fibrin (PRF) matrices will have a positive influence on primary human osteoblasts activity in vitro. A polymeric resorbable scaffold (Osteomesh, OsteoporeTM (OP), Singapore) was combined with differently centrifuged PRF matrices to evaluate the additional influence of this biologization concept on bone regeneration in vitro. Peripheral blood of three healthy donors was used to gain PRF matrices centrifuged either at High (710× g, 8 min) or Low (44× g, 8 min) relative centrifugal force (RCF) according to the low speed centrifugation concept (LSCC). OP-PRF constructs were cultured with pOBs. POBs cultured on the uncoated OP served as a control. After three and seven days of cultivation, cell culture supernatants were collected to analyze the pOBs activity by determining the concentrations of VEGF, TGF-ß1, PDGF, OPG, IL-8, and ALP- activity. Immunofluorescence staining was used to evaluate the Osteopontin expression of pOBs. After three days, the group of OP+PRFLow+pOBs showed significantly higher expression of IL-8, TGF-ß1, PDGF, and VEGF compared to the group of OP+PRFHigh+pOBs and OP+pOBs. Similar results were observed on day 7. Moreover, OP+PRFLow+pOBs exhibited significantly higher activity of ALP compared to OP+PRFHigh+pOBs and OP+pOBs. Immunofluorescence staining showed a higher number of pOBs adherent to OP+PRFLow+pOBs compared to the groups OP+PRFHigh+pOBs and OP+pOBs. To the best of our knowledge, this study is the first to investigate the osteoblasts activity when cultured on a PRF-coated PCL-mesh in vitro. The presented results suggest that PRFLow centrifuged according to LSCC exhibits autologous blood cells and growth factors, seem to have a significant effect on osteogenesis. Thereby, the combination of OP with PRFLow showed promising results to support bone regeneration. Further in vivo studies are required to verify the results and carry out potential results for clinical translation.

Anti-inflammatory and macrophage polarization effects of Cranberry Proanthocyanidins (PACs) for periodontal and peri-implant disease therapy.

BACKGROUND AND OBJECTIVE: Macrophages' cytokine expression and polarization play a substantial role in the host's "destructive" inflammatory response to periodontal and peri-implant pathogens. This study aimed to evaluate cell viability, anti-inflammatory activity, and macrophage polarization properties of different cranberry concentrates. METHODS: THP-1 cells (monocytic line) were treated with phorbol myristic acid to induce macrophage differentiation. Human gingival fibroblasts (HFIB-G cell line), osteosarcoma-derived osteoblasts (SAOS-2 cell line), and induced macrophages were treated with cranberry concentrates at 25, 50, and 100 µg/mL for 120 seconds, 1 hour and 24 hours. Untreated cells at the same time points served as controls. For anti-inflammatory analysis, induced macrophages exposed to cranberry concentrates (A-type PACs) were stimulated with lipopolysaccharides (LPS) derived from E coli for 24 hours. Cell viability, interleukin (IL)-8, IL-1 ß, IL-6, and IL-10 expression of LPS-stimulated macrophages, and macrophage polarization markers were evaluated through determination of live-cell protease activity, enzyme-linked immunosorbent assay, and immunofluorescence staining semi-quantification. RESULTS: Cranberry concentrates (A-type PACs) did not reduce HGF, SAOS-2, and macrophage viability after 24 hours of exposure. Pro-inflammatory cytokine expression (ie IL-8 and IL-6) was downregulated in LPS-stimulated macrophages by cranberry concentrates at 50 and 100 µg/mL. Anti-inflammatory IL-10 expression was significantly upregulated in LPS-stimulated macrophages by cranberry concentrates at 100 µg/mL after 24 hours of exposure. M1 polarization significantly decreased when LPS-stimulated macrophages were exposed to cranberry concentrates. High levels of positive M1 macrophages were present in all untreated control groups. M2 polarization significantly increased at all LPS-stimulated macrophages exposed to cranberry concentrates for 1 and 24 hours. CONCLUSION: Cranberry-derived proanthocyanidins may have the potential to act as an anti-inflammatory component in the therapy of periodontal and peri-implant diseases.

Changes in platelet-rich fibrin composition after trauma and surgical intervention.

Reconstruction surgery after trauma has always been a big challenge. The use of platelet-rich fibrin (PRF) as an autologous source could help accelerate the regeneration time of bone and soft tissues. PRF is a blood concentrate system obtained through a one-step centrifugation. The 3D matrix of the PRF clot serves as a reservoir of growth factors. In the present study, PRF from patients after trauma and after surgery was compared to healthy volunteers to evaluate the composition and potential of PRF as a possible autologous tool for growth factor delivering. Two PRF species and blood from healthy volunteers and patients after trauma and after following surgical intervention were compared (n = 10). FACS analysis, ELISA, and histological analysis were performed. The Pro-inflammatory potential after trauma and after the intervention is increased in PRF species whereas cellular and humoral factors with distinct regenerative potential remained on a level comparable to peripheral blood. It was demonstrated that cells in PRF express more pro-inflammatory species when obtained after the surgical intervention compared to PRF from healthy individuals. This pro-inflammatory potential should be considered, when combining PRF with bone substitute materials for reconstruction surgery prone to foreign body giant cell reaction. Accordingly, solid or injectable PRF-based matrices should preferably be prepared prior to a surgical intervention.

Modification of collagen-based sponges can induce an upshift of the early inflammatory response and a chronic inflammatory reaction led by M1 macrophages: an in vivo study.

BACKGROUND: The present study evaluated the cellular tissue reaction of two equine-derived collagen hemostatic sponges (E-CHS), which differed in thickness after pressing, over 30 days in vivo. The inflammatory response during physiological wound healing in sham-operated animals was used as control group. MATERIAL AND METHODS: First, the E-CHS was pressed by applying constant pressure (6.47 ± 0.85 N) for 2 min using a sterile stainless-steel cylinder until the material was uniformly flattened. Consequently, the original (E-CHS), the pressed (P-E-CHS), as well as the control group (CG; sham operation) were studied independently. The 3 groups were evaluated in vivo after subcutaneous implantation in Wistar rats during 3, 15, and 30 days. Histochemical and immunohistochemical methods provided observations of biomaterial degradation rate, cellular inflammatory response, and vascularization pattern. A derivative of human blood known as platelet-rich fibrin (PRF) was used as an ex vivo model to simulate the initial biomaterial-cell interaction. Segments of E-CHS and P-E-CHS were cultivated for 3 and 6 days with PRF, and the release of pro-inflammatory proteins was measured using ELISA. PRF cultivated alone was used as a control group. RESULTS: At day 3, the CG induced a statistically significant higher presence of monocytes/macrophages (CD68+), pro-inflammatory macrophages (M1; CCR7+), and pro-wound healing macrophages (M2; CD206+) compared to E-CHS and P-E-CHS. At the same time point, P-E-CHS induced a statistically significant higher presence of CD68+ cells compared to E-CHS. After 15 days, E-CHS was invaded by cells and vessels and showed a faster disintegration rate compared to P-E-CHS. On the contrary, cells and vessels were located only in the outer region of P-E-CHS and the biomaterial did not lose its structure and accordingly did not undergo disintegration. The experimental groups induced similar inflammatory reaction primarily with positive pro-inflammatory CD68+/CCR7+ macrophages and a low presence of multinucleated giant cells (MNGCs). At this time point, significantly lower CD68+/CCR7+ macrophages and no MNGCs were detected within the CG when compared to the experimental groups (P < 0.05). After 30 days, E-CHS and P-E-CHS were fully degraded. All groups showed similar inflammatory reaction shifted to a higher presence CD206+ macrophages. A low number of CCR7+ MNGCs were still observable in the implantation bed of both experimental groups. In the ex vivo model, the cells and fibrin from PRF penetrated E-CHS. However, in the case of P-E-CHS, the cells and fibrin stayed on the surface and did not penetrate towards materials central regions. The cultivation of P-E-CHS with PRF induced a statically significant higher release of pro-inflammatory proteins compared to the CG and E-CHS after 3 days. CONCLUSION: Altering the original presentation of a hemostatic sponge biomaterial by pressing modified the initial biomaterial-cell interaction, delayed the early biomaterial's degradation rate, and altered the vascularization pattern. A pressed biomaterial seems to induce a higher inflammatory reaction at early time points. However, altering the biomaterial did not modify the polarization pattern of macrophages compared to physiologic wound healing. The ex vivo model using PRF was shown to be an effective model to simulate the initial biomaterial-cell interaction in vivo. CLINICAL RELEVANCE: A pressed hemostatic sponge could be applied for guided tissue regeneration and guided bone regeneration. In that sense, within the limitations of this study, the results show that the same biomaterial may have two specific clinical indications.

Histomorphometrical assessment of vertical alveolar ridge augmentation using extracted tooth roots in the canine.

OBJECTIVES: To histomorphometrically evaluate the influence of autoclavation on the efficacy of extracted tooth roots (TR) used for vertical alveolar ridge augmentation. MATERIALS AND METHODS: Upper premolars were randomly assigned to either autoclavation (TR-A) or an untreated control group (TR-C) and used as block grafts for vertical alveolar ridge augmentation in both lower quadrants (n = 4 beagle dogs). Tissue biopsies were obtained after 15 weeks of submerged healing. Histological analyses considered gain in ridge height (GRH), augmented area (AA), and the proportion of mineralized (MT) and non-mineralized tissue (NMT). RESULTS: TR-C and TR-A grafts were commonly associated with a complete replacement resorption and a marked gain in ridge height. Significant differences between groups were noted for mean GRH [TR-C: 2.35 ± 0.55 vs. TR-A: 2.46 ± 0.21 mm] and AA [TR-C: 11.88 ± 4.31 vs. TR-A: 8.65 ± 1.59 mm2] values. Within AA, both groups revealed a comparable distribution of mean MT and NMT values. The linear regression analysis pointed to a significant correlation between NMT and AA values. CONCLUSIONS: Both TR-C and TR-A grafts supported vertical alveolar ridge augmentation; however, GRH was improved in the TR-A group. CLINICAL RELEVANCE: TR grafts may serve as a potential alternative for vertical alveolar ridge augmentation.

Three-Dimensional Magnetic Resonance Imaging Volumetry of Radial Forearm Flap Reconstructions After Craniomaxillofacial Tumor Resection.

BACKGROUND: Oral cancer is a common and life threatening disease that requires interdisciplinary treatment and often necessitates complex facial reconstruction. Standard care includes tumor resection, while reconstruction is routinely performed with free radial forearm flaps. As esthetic results are crucial for quality of life, flap size, flap volume, and flap composition have to be considered. To date no standardized measurement of flap volume and shrinkage has been established for routine use. The purpose of this study was therefore to evaluate the transplant volume of radial forearm flaps in craniomaxillofacial reconstruction using magnetic resonance imaging (MRI) volumetry. MATERIAL AND METHODS: Ten postoperative MR sequences of 5 patients were included. All patients had received transplantation of radial forearm flaps after tumor resection and radiation therapy. Evaluated parameters were: sex, age, type of flap, flap volume. Two different observers (1 surgeon and 1 radiologist) segmented transplant volume at three different time points in a postoperative MRI independently and in consensus, using both axial and coronal slices. A nonfat saturated T1 spin echo sequence was used. Mean transplant volume was calculated. RESULTS: A total of 90 volumetric measurements were included. Overall Tvolm was 24.83 cm from axial sections and 27.25 cm from coronal sections. Measurements for axial and coronal orientations differed significantly. Results showed excellent intra- and inter-rater correlation, coefficient for rater A and rater B were 0.91 (axial) and 0.96 (coronal). CONCLUSION: MRI volumetry is a noninvasive reproducible method to quantify volume of free radial forearm flaps in situ but should follow specific considerations for best results.