The effect of three hemostatic agents on early bone healing in an animal model

Tranexamic acid loaded in a physically crosslinked trilaminate dressing for local hemorrhage control: Preparation, characterization, and in-vivo assessment using two different animal models

This work aimed at formulating a trilaminate dressing loaded with tranexamic acid. It consisted of a layer of 3 % sodium hyaluronate to initiate hemostasis. It was followed by a mixed porous layer of 5 % polyvinyl alcohol and 2 % kappa-carrageenan. This layer acted as a drug reservoir that controlled its release. The third layer was 5 % ethyl cellulose backing layer for unidirectional release of tranexamic acid towards the wound. The 3 layers were physically crosslinked by hydrogen bonding as confirmed by Infrared spectroscopy. Swelling and release studies were performed, and results proposed that increasing number of layers decreased swelling properties and sustained release of tranexamic acid for 8 h. In vitro blood coagulation study was performed using human blood and showed that the dressing significantly decreased coagulation time by 70.5 % compared to the negative control. In vivo hemostatic activity was evaluated using tail amputation model in Wistar rats. Statistical analysis showed the dressing could stop bleeding in a punctured artery of the rat tail faster than the negative control by 59 %. Cranial bone defect model in New Zealand rabbits was performed to check for bone hemostasis and showed significant decrease in the hemostatic time by 80 % compared to the control.

Topical hemostatic agents in neurosurgery, a comprehensive review: 15 years update

Hemostasis in neurosurgery is of utmost importance. Bleeding management is one of the crucial steps of each neurosurgical procedure. Several strategies, namely thermal, mechanical, electric, and chemical, have been advocated to face blood loss within the surgical field. Over time, countless hemostatic agents and devices have been proposed. Furthermore, the ever-growing recent technological innovation has made available several novel and interesting tools. Pursuant to their impact on surgical practice, we perceived the imperative to update our previous disclosure paper. Therefore, we reviewed the literature and analyzed technical data sheets of each product in order to provide an updated and comprehensive overview in regard to chemical properties, mechanisms of action, use, complications, tricks, and pitfalls of topical hemostatic agents.

The sole and combined effects of gelatin-thrombin matrix and freeze-dried bone allograft on early bone healing

Aims

Gelatin-thrombin matrix (GTM) is a hemostatic agent with applications in maxillofacial surgery consisting of human-derived thrombin and bovine-derived gelatin matrix. The aim of this study was to evaluate the efficacy of GTM alone or with freeze-dried bone allograft (FDBA) in improving early bone healing.

Materials and Methods

Forty-six adult male Sprague-Dawley rats were used. All animals were randomly assigned to a control group (n = 4) and three study groups (n = 14). Each group was divided into two subgroups for histomorphometric and histological analyses at weeks 1 and 4. The new bone formation, inflammation, fibrosis, necrosis, foreign body reaction, and bone healing scores were evaluated based on the histopathological findings. Multiple comparisons were performed using the Kruskal-Wallis test. Variables that were not normally distributed were evaluated using the Mann-Whitney U test.

Results

At 1 week, the GTM + FDBA group showed less bone formation (mean ± SD: 0.08 ± 0.03 mm²), compared with the study and control groups (FDBA: 0.15 ± 0.06 mm²; GTM: 0.13 ± 0.06 mm²). At 4 weeks, the GTM group (0.48 ± 0.1 mm²) showed more bone formation than the GTM + FDBA group (0.33 ± 0.17 mm²). Foreign body reactions were observed at weeks 1 and 4 in all GTM-containing groups.

Conclusions

Within the limitations of this study, GTM group did not show a significant difference in bone formation compared with the control group. GTM did not inhibit bone healing at 1 and 4 weeks, and no significant difference was observed compared with the control groups. GTM was more effective for bone healing when administered without FDBA. GTM is considered safe when bone hemorrhage is encountered.

Comparison of Autologous Blood Clots with Fibrin Sealant as Scaffolds for Promoting Human Muscle-Derived Stem Cell-Mediated Bone Regeneration

Background. Fibrin sealant has been used as a scaffold to deliver genetically modified human muscle-derived stem cells (hMDSCs) for bone regeneration. Alternatively, autologous blood clots are safe, economic scaffolds. This study compared autologous blood clot (BC) with fibrin sealant (FS) as a scaffold to deliver lenti-BMP2/GFP-transduced hMDSCs for bone regeneration. Methods. In vitro osteogenic differentiation was performed using 3D pellet culture and evaluated using microCT and Von Kossa staining. The lenti-GFP transduced cells were then mixed with human blood for evaluation of osteogenic differentiation. Furthermore, a murine critical- sized calvarial defect model was utilized to compare BC and FS scaffolds for lenti-BMP2/GFP-transduced hMDSCs mediated bone regeneration and evaluated with micro-CT and histology. Results. Lenti-BMP2/GFP transduced hMDSCs formed significantly larger mineralized pellets than non-transduced hMDSCs. hMDSCs within the human blood clot migrated out and differentiated into ALP⁺ osteoblasts. In vivo, BC resulted in significantly less new bone formation within a critical-sized calvarial bone defect than FS scaffold, despite no difference observed for GFP⁺ donor cells, osteoclasts, and osteoblasts in the newly formed bone. Conclusions. Human lenti-BMP2/GFP-transduced hMDSCs can efficiently undergo osteogenic differentiation in vitro. Unexpectedly, the newly regenerated bone in BC group was significantly less than the FS group. The autologous blood clot scaffold is less efficacious for delivering stem cells for bone regeneration than fibrin sealant.

The effect of the new hemostatic agent Ostene® on bone healing: An experimental study in rabbits

Introduction: Ostene® is a water-soluble wax-like alkylene oxide copolymer preparation for use as a mechanical hemostatic agent. This study aims to evaluate the effects of Ostene® on bone healing. Materials and Methods: Twenty albino rabbits were divided into four groups according to post-treatment follow-up (24 hr, 3 days, 7 days, 14 days) with five rabbits in each group. Each rabbit in all groups was treated with two study materials (Ostene® and Gelfoam®). Three holes were made in the mandibular bone of each rabbit using 5mm surgical bur; two holes were made on right side: one for testing Ostene® and another for Gelfoam®. A third hole, on the left side of mandible, was not treated, and was used as a control. Finally, the incision was closed. The specimens were collected at different days post-treatment and examined by histopathology. Result and Discussion: This study showed that there is a significant difference (p-value≤ 0.05) between the Ostene® group and the other groups (Gelfoam® and control). At 24 hr post intervention, there is a significant difference in osteoblast cell formation (p-value=0.03), and osteoclast cell formation (p-value=0.05). New blood vessel formation, osteoblast and osteoclast cell formation for Ostene® group at 3 days post-intervention were also significantly different (p-values = 0.05, 0.03, 0.04, respectively). At 7 days post-intervention p-values were 0.05 for osteoblast formation and 0.04 for osteoclast formation, respectively. After 14 days of healing p-value for osteoblast cell formation in the Ostene® group was 0.05 and 0.04 for osteoclast cell formation. Conclusions: The bone hemostatic agent Ostene® is an effective at enhancing osteogenesis by initiating proliferation of osteoblast and osteoclast cells.

Delayed Socket Healing After Dental Extraction in Patients Undergoing Myelosuppressive Chemotherapy for Hematological Malignancy: Incidence and Risk Factors

PURPOSE

The purpose of this study was to measure the frequency and identify factors associated with delayed socket healing after dental extraction in patients undergoing myelosuppressive chemotherapy for hematologic malignancy.

MATERIALS AND METHODS

This prospective cohort study focused on delayed healing after extraction in patients with hematologic malignancy. Sockets with delayed healing were defined as those with intense pain and bone exposure 1 week postoperatively. Patients with and without delayed socket healing were compared using the Fisher exact test and Mann-Whitney U test with some variables. Receiver operating characteristics curve analysis was conducted to define cutoff values for delayed healing.

RESULTS

One hundred ninety-four dental extractions in 93 patients (median age, 64 yr; range, 20 to 85 yr) were analyzed. The incidence of delayed socket healing was 7.5% (7 of 93 patients). There was no postoperative bleeding. Older age, type of hematologic malignancy (acute leukemia), shorter time from dental extraction to initiation of chemotherapy, low platelet count or hemoglobin level, requirement for red blood cell concentrate or platelet transfusion, and use of an absorbable hemostatic agent were statistically associated with the occurrence of delayed socket healing. Platelet and hemoglobin cutoffs were 4.6 × 10⁴/μL and 7.7 g/dL, respectively.

CONCLUSIONS

Although dental extraction can be safely performed in patients undergoing myelosuppressive chemotherapy for hematologic malignancy, oral surgeons should understand the potential risk for delayed socket healing. When considering dental extraction, patients with hematologic malignancy and low hemoglobin or platelet levels should be informed about the possibility of delayed socket healing.

Bilayer electrospun poly(vinyl alcohol)–gelatin mat and biphasic calcium phosphate–pectin–gelatin hydrogel for application in bone hemorrhage

A bilayer composite scaffold consisting of a biphasic calcium phosphate–pectin–gelatin hydrogel and an electrospun poly(vinyl alcohol)–gelatin matrix was developed and investigated for application in bone hemorrhage. The aim of this research is to develop a new biomaterial system that provides a hemostatic effect on bone hemorrhage and does not interfere with native bone regeneration. The role of electrospun poly(vinyl alcohol)–gelatin in scaffolds is to provide the covering of the wound, while encapsulation and absorption of red blood cells are attributed to the biphasic calcium phosphate–pectin–gelatin hydrogel. Cell viability and cell proliferation were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Live/Dead assay, and immunofluorescence assay using pre-osteoblast MC3T3-E1 cells. The effects with and without hemostatic bilayer scaffolds on rat calvaria were compared at 1 and 3 weeks. The hemostatic bilayer agent showed good blood absorption behavior and efficient bone healing properties after 3 weeks, as observed by micro-computed tomography and hematoxylin and eosin staining.

In vivo assessment of new resorbable PEG-PPG-PEG copolymer/starch bone wax in bone healing and tissue reaction of bone defect in rabbit model

In this study, in vivo performance of novel resorbable bone wax based on a miscible blend between PEG-PPG-PEG copolymer mixtures and pregelatinized starch at 0 and 25 percent by weight including hemostasis, tissue reaction and bone healing in a non-critical size tibia defect model were assessed and compared with commercial non-resorbable bone wax. Systemic reaction was evaluated by blood chemistry while local reaction, bone quantity and quality were evaluated by microcomputed tomography (microCT) and histology analyses. It was observed that the resorbable bone waxes did not show any adverse systemic reaction and resorbed from the defects within approximately 2 days after application. They were as effective as the commercial bone wax in hemostasis, but provided better adherence to the bone surface. The incorporation of pre-gelatinized starch in the formulation could further help in improved molding texture and decreased glove adherence. MicroCT and histology analyses showed that the resorbable bone waxes did not inhibit the osteogenesis whereas commercial bone wax impaired bone healing and displayed inflammation and foreign body reactions.

Comparison of the effects of new folkloric hemostatic agent on peripheral nerve function: an electrophysiologic study in rats

OBJECTIVE

The aim was to evaluate the effects of a new folkloric medicinal plant extract on peripheral nerve function compared with oxidized regenerated cellulose (OC) and bovine collagen (BC).

STUDY DESIGN

Under ketamine anesthesia a total of 40 male Sprague-Dawley rat right sciatic nerves were identified. Animals were randomly divided into 5 groups: OC, BC, ankaferd blood stopper (ABS), and negative and positive control groups. The recordings of nerve potentials were carried out using an electrophysiologic data acquisition system. After the application of substances, the nerve conduction velocity (NCV) was recorded for immediate (30 min), early (120 min), and delayed (3 wk) effects on nerve function.

RESULTS

Statistically, differences were not found among the hemostatic agents (OC, BC, and ABS) at baseline and all tested periods (early, immediate, and delayed; P > .05). The positive control group exhibited lower NCV values compared with the other solutions at the 30-minute period (P < .05) as well as the other tested time periods (P > .05). OC exhibited NCV values closer to the positive control group at 120 minutes (P > .05).

CONCLUSIONS

Folkloric medicinal hemostatic agent could be considered as an acceptable hemostatic material without resulting in any serious peripheral nerve function alterations. The possible desirable effects of bovine collagen and undesirable effects of oxidized cellulose on peripheral nerve function should not be overlooked.

Bacterial cellulose-hydroxyapatite nanocomposites for bone regeneration

The aim of this study was to develop and to evaluate the biological properties of bacterial cellulose-hydroxyapatite (BC-HA) nanocomposite membranes for bone regeneration. Nanocomposites were prepared from bacterial cellulose membranes sequentially incubated in solutions of CaCl₂ followed by Na₂HPO₄. BC-HA membranes were evaluated in noncritical bone defects in rat tibiae at 1, 4, and 16 weeks. Thermogravimetric analyses showed that the amount of the mineral phase was 40%–50% of the total weight. Spectroscopy, electronic microscopy/energy dispersive X-ray analyses, and X-ray diffraction showed formation of HA crystals on BC nanofibres. Low crystallinity HA crystals presented Ca/P a molar ratio of 1.5 (calcium-deficient HA), similar to physiological bone. Fourier transformed infrared spectroscopy analysis showed bands assigned to phosphate and carbonate ions. In vivo tests showed no inflammatory reaction after 1 week. After 4 weeks, defects were observed to be completely filled in by new bone tissue. The BC-HA membranes were effective for bone regeneration.