Human Fibrin Research Articles

Prospective single-center feasible study of innovative autorelease bile duct supporter to delay adverse events after endoscopic papillectomy.

BACKGROUNDConventional endoscopic papillectomy (EP) is safe and effective for the treatment of small papilla adenoma to even large laterally spreading tumors of duodenum lesions. As reported by some existing studies, temporarily placing a prophylactic stent in the pancreatic and bile duct can lower the risk of this perioperative complication.AIMTo evaluate the usefulness, convenience, safety, and short-term results of a novel autorelease bile duct supporter after EP procedure, especially the effectiveness in preventing EP.METHODSA single-center comparison study was conducted to verify the feasibility of the novel method. After EP, a metallic endoclip and human fibrin sealant kit were applied for protection. The autorelease bile duct supporter fell into the duct segment and the intestinal segment. Specifically, the intestinal segment was extended by nearly 5 cm as a bent coil. The bile was isolated from the pancreatic juice using an autorelease bile duct supporter, which protected the wound surface. The autorelease bile duct supporter fell off naturally and arrived in colon nearly 10 d after the operation.RESULTS En bloc endoscopic resection was performed in 6/8 patients (75%), and piecemeal resection was performed in 2/8 of patients (25%). None of the above patients were positive for neoplastic lymph nodes or distant metastasis. No cases of mortality, hemorrhage, delayed perforation, pancreatitis, cholangitis or duct stenosis with the conventional medical treatment were reported. The autorelease bile duct supporter in 7 of 8 patients fell off naturally and arrived in colon 10 d after the operation. One autorelease bile duct supporter was successfully removed using forceps or snare under endoscopy. No recurrence was identified during the 8-mo (ranging from 6-9 mo) follow-up period.CONCLUSIONIn brief, it was found that the autorelease bile duct supporter could decrease the frequency of procedure-associated complications without second endoscopic retraction. Secure closure of the resection wound with clips and fibrin glue were indicated to be promising and important for the use of autorelease bile duct supporters. Well-designed larger-scale comparative studies are required to confirm the findings of this study.

Possible Proliferative Impact of Human Platelet-Rich Fibrin Obtained From Controlled Type 2 Diabetic Patients on Human Dental Pulp Stem Cells (In Vitro Study)

Possible Proliferative Impact of Human Platelet-Rich Fibrin Obtained From Controlled Type 2 Diabetic Patients on Human Dental Pulp Stem Cells (In Vitro Study)

A Trial to Improve the Outcome of Patients with Cleft Palate Repair by Using Human Fibrin Glue: A Study in 20 Cases

A Trial to Improve the Outcome of Patients with Cleft Palate Repair by Using Human Fibrin Glue: A Study in 20 Cases

A trial to improve the outcome of patients with cleft palate repair by using human fibrin glue: a study in 20 cases

A trial to improve the outcome of patients with cleft palate repair by using human fibrin glue: a study in 20 cases

Dual function of a bumblebee (Bombus ignitus) serine protease inhibitor that acts as a microbicidal peptide and anti-fibrinolytic venom toxin

In bee venoms, low–molecular-weight peptides, including serine protease inhibitors (SPIs), exhibit multifunctional activities. Although SPIs in bee venoms are relatively well known, those that function in both the body and secreted venom of bees are not well-characterized. In this study, we identified a bumblebee (Bombus ignitus) SPI (BiSPI) that displays microbicidal and anti-fibrinolytic activities. BiSPI was found to consist of a trypsin inhibitor–like domain containing a P1 site and ten cysteine residues. We observed that the BiSPI gene was ubiquitously transcribed in the body, including the venom glands. In correlation, the BiSPI protein was detected both in the body and secreted venom by using an antibody against a recombinant BiSPI peptide produced in baculovirus-infected insect cells. Recombinant BiSPI exhibited inhibitory activity against trypsin but not chymotrypsin and inhibited microbial serine proteases and plasmin but not elastase or thrombin. Moreover, recombinant BiSPI recognized carbohydrates and bound to fungi and gram-negative and gram-positive bacteria. Consistent with these properties, recombinant BiSPI exhibited microbicidal activities against bacteria and fungi through induction of structural damage by binding to the microbial surfaces. Additionally, recombinant BiSPI inhibited the plasmin-mediated degradation of human fibrin and was thus concluded to exhibit anti-fibrinolytic activity. Moreover, the peptide showed no effect on hemolysis. These findings demonstrate the dual function of BiSPI, which acts as a microbicidal peptide and anti-fibrinolytic venom toxin.

Preparation and Characterization of Plasma-Derived Fibrin Hydrogels Modified by Alginate di-Aldehyde.

Fibrin hydrogels are one of the most popular scaffolds used in tissue engineering due to their excellent biological properties. Special attention should be paid to the use of human plasma-derived fibrin hydrogels as a 3D scaffold in the production of autologous skin grafts, skeletal muscle regeneration and bone tissue repair. However, mechanical weakness and rapid degradation, which causes plasma-derived fibrin matrices to shrink significantly, prompted us to improve their stability. In our study, plasma-derived fibrin was chemically bonded to oxidized alginate (alginate di-aldehyde, ADA) at 10%, 20%, 50% and 80% oxidation, by Schiff base formation, to produce natural hydrogels for tissue engineering applications. First, gelling time studies showed that the degree of ADA oxidation inhibits fibrin polymerization, which we associate with fiber increment and decreased fiber density; moreover, the storage modulus increased when increasing the final volume of CaCl2 (1% w/v) from 80 µL to 200 µL per milliliter of hydrogel. The contraction was similar in matrices with and without human primary fibroblasts (hFBs). In addition, proliferation studies with encapsulated hFBs showed an increment in cell viability in hydrogels with ADA at 10% oxidation at days 1 and 3 with 80 µL of CaCl2; by increasing this compound (CaCl2), the proliferation does not significantly increase until day 7. In the presence of 10% alginate oxidation, the proliferation results are similar to the control, in contrast to the sample with 20% oxidation whose proliferation decreases. Finally, the viability studies showed that the hFB morphology was maintained regardless of the degree of oxidation used; however, the quantity of CaCl2 influences the spread of the hFBs.

Assembly of skin substitute by cross-linking natural biomaterials on synthetic biodegradable porous mat for critical-size full-thickness burn wound regeneration

Human skin architecture comprises several interpenetrating macromolecules seen as organized extracellular matrix (ECM). For regeneration of critical-size acute and chronic wounds, substituting the damaged tissue with artificially assembled biomolecules offer an interactive milieu. This study reports development and preclinical evaluation of a biodegradable and immuno-compatible scaffold for regeneration of critical-size (4 × 4 cm2) full-thickness rabbit burn wounds. The designed wound care product comprises synthetic terpolymer poly(L-Lactide-co-Glycolide-co-Caprolactone) (PLGC), human clinical-grade fibrin (FIB), and hyaluronic acid (HA), termed as PLGCFIBHA. Here, clotting of fibrinogen concentrate (FC) with excess thrombin in the scaffold create an interpenetrating FIB network harnessed with adhesive molecules like fibronectin and laminin present in FC with exogenous HA to produce ECM-like milieu on porous PLGC. Penetrating into porous PLGCFIBHA, long term study showed a regulated fibroblast growth resulting in non-fibrotic dermal-like tissue in vitro. The freeze-dried PLGCFIBHA with residual thrombin facilitated suture-less, hemostatic matrix adhesion to the wound bed in vivo. By 28 d, mature and scar-less epidermis-dermis formation with skin appendages was evident in the PLGCFIBHA-treated wound area. Both negative (untreated/sham) and positive (commercial matrix-treated) control wounds showed incomplete regeneration. The PLGCFIBHA-treated wounds were comparable to native skin by 56 d. These regenerative outcomes upon single application of PLGCFIBHA confirms its potential translational value for wound care.

Comparison of modified rapid deployment hemostat dressing with standard haemostat as part of standardized perihepatic packing for major liver trauma in a level 1 trauma center

Introduction Uncontrolled hemorrhage is a major cause of mortality in surgery and trauma. Damage control surgery (DCS) is essential in the management of these cases. The use of topical hemostatic agents has increased over the last two decades with the evolution of DCS and trauma-induced coagulopathy. The aim of this study was to compare the performance of standard perihepatic packing with the addition of either a MRDH (modified rapid deployment hemostat) or a non-MRDH hemostatic dressing. Methods This was a retrospective, comparative analysis of prospectively collected data held in the registry of a level I trauma center in Bologna, Italy, between 2005 and 2019. 33 patients with grade IV/V liver injuries who underwent a standardized perihepatic packing with hemostatic dressings were enrolled in the study. The study group included 21 patients treated with standard packing plus MRDH. The control group included 12 patients treated with standard packing plus a combination of fibrillar absorbable hemostat and human fibrin sealant. Results The two groups were homogeneous in terms of age and American Association for the Surgery of Trauma (AAST) grade although the MRDH one seemed to have more severe injury: hemodynamic instability was present in 95% of MRDH patients vs. 83% in the control group. Also, Injury Severity Score (ISS) and New Injury Severity Score (NISS) were 41 vs 35.5 and 47 vs 39.1, respectively. The incidence of re-bleeding requiring repacking at the second-look laparotomy was 4.7% in MRDH patients vs. 16.7% in non-MRDH patients ( p = .5, OR = 4). The overall complication rate was of 23% after the introduction of MRDH vs. 81% in the control group. Conclusion Despite the potential effectiveness of MRDH, this study does not seem to confirm a significant superiority of this hemostat over the standard.

Bioactive and degradable hydrogel based on human platelet-rich plasma fibrin matrix combined with oxidized alginate in a diabetic mice wound healing model

In the present study we developed an injectable, bioactive and degradable hydrogel composed of alginate at 2.5% oxidation degree and calcium-activated platelet rich plasma (PRP) for wound healing applications (PRP-HG-2.5%). The alginate gives mechanical support to the hydrogel while the activated PRP provides growth factors that enhance wound healing and fibrin which creates an adequate microenvironment for cell migration and proliferation. The rheological and mechanical properties of the hydrogel were characterized. Further characterization revealed that PRP-HG-2.5% showed a faster hydrolitic degradation rate than unmodified alginate and a similar platelet derived growth factor (PDGF-BB) release profile. In vitro efficacy studies, carried out in human fibroblasts and keratinocytes, showed that PRP-HG-2.5% was not cytotoxic and that it was able to promote cell adhesion and proliferation. Thereafter, in an in vivo full thickness wound healing study conducted in diabetic mice, no differences were found among PRP-HG-2.5% and its counterpart without PRP, likely due to the xenogeneic origin of the PRP. This hypothesis was validated in vitro, since a cytotoxic effect was observed after human PRP application to mouse fibroblasts. Therefore, PRP-HG-2.5% might be a promising strategy for chronic woundstreatment, although its effectiveness should be evaluated in a more reliable preclinical model.

Effect of Pterygium Removal Combined with Conjunctival Autograft on Corneal Parameters in Swept-Source Imaging.

Background: Both pterygium ingrowth and excision determine alterations in corneal topography. The aim of this study was to evaluate the influence of pterygium removal combined with conjunctival autografts in addition to the use of human fibrin tissue glue on changes in corneal parameters as measured by 3-D swept-source anterior segment optical coherence tomography (AS-OCT) imaging. Methods: Sixteen eyes (16 patients) with pterygium that qualified for surgical treatment were enrolled in this study. Eye examination, slit lamp, and 3-D AS-OCT (CASIA 2) assessment were performed before the surgery and 7 days, 1 month, and 6 months after pterygium excision. Topographic parameters of both anterior and posterior surfaces of the cornea were analysed at each follow-up visit. Results: The gradual decrease in total astigmatism power from preoperative median 2.75 (6.15) D to 1.2 (1.1) D at 6-month follow-up (p = 0.034) was noted from the day 7 visit. Values were strongly influenced by variations of anterior cornea astigmatism. In contrast, a gradual total HOA reduction at the 1-month (from median 0.79 (1.3) D to 0.44 (0.27) D; p = 0.038) and at 6-month visits (0.25 (0.09); p = 0.001) was observed. Similarly, values were strongly influenced by variations of the anterior. Additionally, total average keratometry values increased from preoperative 44.05 (2.25) D to 44.6 (1.9) (p = 0.043) 1 month after the surgery. Conclusions: Significant steepening of the anterior cornea and a reduction in both astigmatism and HOA were observed after pterygium excision. The anterior corneal surface was an essential component of the total postoperative corneal topography values. Three-dimensional swept-source AS-OCT imaging seems to be a valuable tool for monitoring both the progression of the disease and postoperative effects in pterygium eyes.

Endovascular repair of ruptured abdominal aortic aneurysms assisted by double balloon occlusion technique combined with intra-aneurysm fibrin binder injection technique

Objective: To investigate the long-term efficacy and safety of alternating double balloon occlusion combined with intra-aneurysm injection of human fibrin binder in the endovascular repair of ruptured abdominal aortic aneurysm (rAAA). Methods: The clinical data of 28 patients with rAAA admitted to Department of Vascular Surgery, the Fourth Affiliated Hospital of Guangxi Medical University from January 2015 to December 2019 were retrospectively analyzed. There were 23 males and 5 females, aged (62±5) years (range: 46 to 88 years).The maximum diameter of the tumors was (65.2±10.5) mm (range: 47.3 to 100.5 mm), all of which were subrenal rAAA. The intraoperative EVAR for abdominal aortic aneurysm was successfully performed under the emergency green channel procedure, and this surgery was assisted used the double balloon occlusion technique in aorta of inferior renal and superior renalcombined with intraoperative human fibrin binder injection technique. Observation indexes included: patients with preoperative preparation, operation time, hospitalization days, surgical treatment success rate and the incidence of postoperative complications, and aortic stent form during the follow-up period, the incidence of leakage, branch stents patency rate and infection rates. Results: The preoperative preparation time of 28 patients was (45.5±8.5) minutes (range:20 to 100 minutes). The operation time was (100.0±15.5) minutes (range:85 to 210 minutes), the ICU stay time was (7±2) days(range:1 to 17 days). The length of hospitalization was (13.5±2.5) days(range:5 to 43 days). The success rate of surgical treatment was 92.9% (26/28). Two patients died, 1 case died of postoperative multifocal lacunar cerebral infarction and massive gastrointestinal hemorrhage, and another elderly patient (84 years old) died of massive abdominal fluid due to preoperative abdominal aortic aneurysm rupture, postoperative complicated with significant abdominal compartment syndrome, and secondary multiple organ failure. Balloon occlusion of the upper renal aorta took (13±2)minutes (range:12 to 30 minutes). The intraoperative injection of fibrin adhesive was (14±2) ml(range:6 to 28 ml) in 22 cases. The incidence of major postoperative complications was 57.1% (16/28). Among the 26 patients who survived the surgery, 69.2% (18/26) completed the 3-year follow-up, and the follow-up time was (30±3) months(range:13 to 36 months). During the follow-up, the aortic stent was in good shape without obvious displacement. The incidence of leakage within 6 months after the operation was 10.7% (3/28), and there was no internal leakage in the patients who were followed up for 36 months after the operation. The patency rate of renal artery and iliac artery branch stents was 16/18. The incidence of stent infection was 7.7% (2/26), 1 case occurred at 1 month and another case at 6 months, respectively. All patients recovered after prolonged intensive anti-infection therapy. Conclusions: Under the standard emergency treatment process, the double balloon alternating occlusion technique combined with the intra-aneurysm injection of human fibrin adhesive technique can assist the successful completion of the endovascular repair of rAAA, effectively improve the success rate of treatment for patients, and reduce the incidence of postoperative leakage and serious complications. The mid-term and long-term results of EVAR for rAAA are good, safe and reliable.

SOME CURIOUS FINDINGS HAIR FOLLICLES BIOELECTROMAGNETIC RADIATION EXPRESSED AS LIGHT DISPLACING MATTER IN ITS PATH AND THE CONTRALATERAL EMISSION OF MAGNETIC FIELDS FOUND IN THE HAIR SHAFT

BACKGROUND
 In physics the term light refers to electromagnetic radiation, which includes visible light, which has also been described as exerting physical pressure on matter in its path; this could be explained by the “particle nature of light”. To date light rays emission experiments has been done mainly on non-living matter. This manuscript will show in vitro results where biological tissue (hair follicles) is shown emitting electromagnetic radiation in a light form and displacing particles in its path. Additionally the hair shaft one-sided biomagnetism is shown.
 METHODS
 A mini-review of prior experiments by this author and others are herein presented where bioelectromagnetic fields expressed as light are shown displacing matter of ferric cyanide chemical compounds. A seminal paper published in 1980, is also included where human hair follicles had been documented as emitting magnetic fields when applying pressure on the human scalp.
 RESULTS
 Findings are presented where light rays or flashes emitted by hair follicles are documented to exert pressure in matter in its path causing displacement; and in one case a flash of light seen as a primary factor in totally reversing turmoil caused by a piezoelectric or pressure induced maneuver. As an incidental finding: The hair shaft is also found to express one-sided magnetic fields similar to inanimate magnets inhibiting human blood issue fibrin formation (clot formation).
 CONCLUSIONS
 Presented is a mini-review of biological tissue previously found to emit magnetic fields, now also expressed as light. The light is displayed shown as a “flash” or a “stream”, in both instances displacing matter in its path. The light flash also appears to be a primary factor in bringing equilibrium into the piezoelectric disturbed bioelectromagnetic field. Question arise: What is/are the biological/molecular consequences of living tissue under stress emitting light energy? Why is the hair shaft bioelectromamagnetic field shown in a contralateral fashion, this when the hair follicle is not? Further research is recommended.

Evaluation of albumin coated xenograft with platelet rich fibrin in socket preservation after tooth extraction

Objective: The present study was performed to evaluate the effect of addition of human serum albumin and platelet rich fibrin to xenograft bone for socket preservation. Material and Methods: 20 patients seeking treatment for badly broken teeth (lower premolars and molars) 10 patients in each group. In the first (study) group, the patients will be subjecting to extraction of badly decayed non restorable tooth then insertion of human albumin coated xenograft bone (OneGraft natural collagenated bovine bone graft 1.0 -2.0mm grain size Bioimplon, Germany) and platelet rich fibrin. In the second (controlled) group, the patients will be subjecting to extraction of badly decayed non restorable tooth without xenograft insertion. CBCT was done to evaluate; bone density, alveolar bone height at the site of extraction and bone graft addition. Bone Density and height was measured at alveolar bone crest & middle of the socket at region of interest (ROI) immediately & at 6 months post operatively. Results: In albumin coated xenograft with PRF group showed less decrease in buccal, lingual height and width , increase in bottom of socket and increase in bone density measurements. Conclusion: the use of albumin coated xenograft with PRF were effective in socket preservation , significantly minimized ridge resorption in all dimensions, accelerate the bone healing and shorting the time period for rehabilitation than the normal sequence of healing.

Differentiation of Patients with Type 1 Von Willebrand Disease Vs. Low Normal Levels of the Von Willebrand Factor Using a Very High Shear Rate, Non-Citrated Blood Flow System

Background: A precise approach to the diagnosis of von Willebrand disease (vWD) remains elusive. One important reason is that vWD is a blood flow‐related disorder: a von Willebrand factor (vWF)‐platelet GPIb binding defect exists in this condition under the high shear‐rate (>1000 sec‐1 in whole blood; >3000 sec‐1 in PRP) conditions of physiologic blood flow which exist in the arterioles of mucous membranes, from which most bleeding in vWD occurs.Objectives: The aims of this work are 1) to differentiate patients with true type 1 von Willebrand disease or symptomatic low vWF from normal controls and those with asymptomatic low vWF, as some patients with low vWF have a bleeding phenotype; and 2) to demonstrate the feasibility of a microfluidic device to so differentiate at a shear rate of 4000 sec-1 and with a minimal blood volume.Methods: We studied in replicate 10 patients (mean 19.6 yrs) with type 1 vWD, diagnosed according to the 2007 NHLBI clinical guidelines, 4 other subjects considered to have type 1 vWD based on low levels of the vWF, and 8 healthy controls (mean 22.4 yrs). The PDQ bleeding assessment tool was applied to all subjects with or considered to have type 1 vWD. Blood was collected into a plastic tube containing 4 U/ml FC enoxaparin, 1.75 μg/ml of the Tab (anti‐CD41) monoclonal antibody directed against platelet GPIIb, and 1.0 μg/ml of an ALEXA 555‐conjugated rabbit anti‐mouse secondary antibody. Within 30-90 min, the blood was withdrawn at 4,000 sec‐1 through a special flow chamber (Fig. 1) allowing for real-time epifluorescence digital videomicroscopy of platelets interacting with a microfibrillar collagen substrate. With MetaMorph software (Universal Imaging) we quantified the percent area (PA) covered by adherent platelet aggregates (Fig. 2) within a 435 μm x 580 μm field of view (1,447,680 pixels). From values for PA vs. time (Fig. 3) we also calculated the rate (R) of platelet adhesion. In some studies, we imaged fibrin deposition vs. time, using the monoclonal antibody 59D8, which is directed against human fibrin β-chain, and a fluorescent secondary antibody.Results: As shown in Fig. 4, at 4,000 sec-1 R for normal controls was 2.1-fold (p < 0.00001) greater than that for patients (Group I), while from previous work we found no difference at 667 sec-1 and only a 1.4-fold difference at 1330 sec-1. PA at 2 min for controls increased with shear rate from 7.5 at 667 sec-1 and 12.8 at 1,330 sec-1, but then decreased to 8.6 at 4,000 sec-1. In contrast, PA for patients (same units) increased from 8.0 at 667 sec-1 to only 9.5 at 1330 sec-1, and then decreased to 5.3 at 4,000 sec-1. Importantly, all ten patients had values for R that fell below the lower 95th percentile for controls. Four other subjects (Group II), considered to have type 1 disease, proved to have bleeding scores that were ≤ 2. One of these was an adult with absolutely no personal bleeding history despite a family history of vWD. Values for PA and R for these subjects were similar to values for normal subjects. For normal controls and Group I patients, at 270 sec-1, fibrin deposition lagged platelet adhesion/aggregation by 5-7 min, but then occurred in a burst in the slow-flow wakes of platelet aggregates as well as on (activated) platelet membranes. At 4000 sec-1, fibrin deposition, developed within 30 sec and was confined to platelet membranes for both normal controls and Group I patients. Group II subjects were not studied.Conclusions: The novel flow device found that PA and rate of platelet adhesion were significantly reduced under high shear stress in “true” type 1 vWD patients and those with symptomatic low vWF compared to normal controls and those with asymptomatic low vWF. This likely results from the “catch-slip” nature of bonds between the vWF and either platelet GPIb or collagen, which has been well-described for the vWF-GPIb interaction with regard to platelet suspensions. Fibrin deposition occurred on (and/or beneath) forming platelet adhesion/aggregation and was in proportion to the level of platelet adhesion/aggregation. The present approach promises to offer a more definitive means to distinguish patients with true type 1 vWD or those with symptomatic low vWF from either normal controls or those with symptomatic low vWF. [Display omitted] DisclosuresGrabowski:CSL Behring: Membership on an entity's Board of Directors or advisory committees, Research Funding.

In Rheumatoid Arthritis Patients, HLA-DRB1*04:01 and Rheumatoid Nodules Are Associated With ACPA to a Particular Fibrin Epitope.

ObjectivesRheumatoid arthritis (RA) is associated with HLA-DRB1 genes encoding the shared epitope (SE), a 5-amino acid motive. RA is usually preceded by the emergence of anti-citrullinated protein/peptide antibodies (ACPAs). Citrulline is a neutral amino acid resulting from post-translational modification of arginine involved in peptidic bounds (arginyl residue) by PeptidylArginine Deiminases (PADs). ACPAs recognize epitopes from citrullinated human fibrin(ogen) (hFib) and can be specifically detected by the AhFibA assay. Five citrullinated peptides derived from hFib together represent almost all of the epitopes recognized by patients with ACPA-positive RA, namely: α36–50cit, α171–185cit, α501–515cit, α621–635cit, and β60–74cit. The use of antibody fine specificities as markers of clinical phenotypes has become a major challenge. Our objective was to study whether RA clinical characteristics and HLA-DRB1 genetic background were associated with a specific reactivity against the epitopes borne by the five peptides.Methods184 ACPA-positive RA patients fulfilling the 2010 ACR/EULAR criteria were studied. Patient characteristics including HLA-DRB1 genotype, were collected from their medical files. Anti-CCP2 antibodies, AhFibA, and antibodies against the five citrullinated hFib (hFib-cit) peptides were analyzed by ELISA.ResultsAnti-α505-515cit antibodies were associated with HLA-DRB1*04:01 (OR = 5.52 [2.00 – 13.64]; p = 0.0003). High level anti-α505-515cit antibodies were associated with rheumatoid nodules (OR = 2.71 [1.00 – 7.16], p= 0.044).ConclusionImmune complexes containing anti-α501-515cit antibodies and rheumatoid factors might be involved in the development of rheumatoid nodules on the HLA-DRB1*04:01 background. Apheresis of these epitope-specific antibodies might be a new therapeutic opportunity for patients with rheumatoid nodules.

Trabecular bone organoids: a micron-scale \u2018humanised\u2019 prototype designed to study the effects of microgravity and degeneration

Bone is a highly responsive organ, which continuously adapts to the environment it is subjected to in order to withstand metabolic demands. These events are difficult to study in this particular tissue in vivo, due to its rigid, mineralised structure and inaccessibility of the cellular component located within. This manuscript presents the development of a micron-scale bone organoid prototype, a concept that can allow the study of bone processes at the cell-tissue interface. The model is constructed with a combination of primary female osteoblastic and osteoclastic cells, seeded onto femoral head micro-trabeculae, where they recapitulate relevant phenotypes and functions. Subsequently, constructs are inserted into a simulated microgravity bioreactor (NASA-Synthecon) to model a pathological state of reduced mechanical stimulation. In these constructs, we detected osteoclastic bone resorption sites, which were different in morphology in the simulated microgravity group compared to static controls. Once encapsulated in human fibrin and exposed to analogue microgravity for 5 days, masses of bone can be observed being lost from the initial structure, allowing to simulate the bone loss process further. Constructs can function as multicellular, organotypic units. Large osteocytic projections and tubular structures develop from the initial construct into the matrix at the millimetre scale. Micron-level fragments from the initial bone structure are detected travelling along these tubules and carried to sites distant from the native structure, where new matrix formation is initiated. We believe this model allows the study of fine-level physiological processes, which can shed light into pathological bone loss and imbalances in bone remodelling.

Potential of a novel scaffold composed of human platelet lysate and fibrin for human corneal endothelial cells.

Cell-based therapies have been emerged to find innovative solutions for corneal endothelial dysfunction. The aim of this study is to investigate the suitability of a blended scaffold containing human platelet lysate (HPL) and fibrin not only for cultivating human corneal endothelial cells (HCECs) but also for serving as a scaffold for the respected cells. We isolated HCECs from human donors and encapsulated the cells with three concentrations of HPL/Fibrin scaffold, namely HPL/Fibrin 1, HPL/Fibrin 2 and HPL/Fibrin 3, by adding 28.9, 57.8 and 86.7mg/dl of fibrinogen to HPL to obtain a final percentage of 10, 20 and 30 % of fibrinogen, respectively. SEM imaging and swelling test were done to characterize the scaffolds. Cell viability assay and cell counting were performed on the cells. HCECs were characterized by morphology and immunocytochemistry. SEM imaging on freeze-dried scaffolds showed higher porosity of HPL/Fibrin 1 and HPL/Fibrin 2 than HPL/Fibrin 3, but larger pores were observed only in HPL/Fibrin 1. Cellular attachment and morphology on HPL/Fibrin 1 were appropriate by SEM imaging. A higher swelling rate was observed in HPL/Fibrin 1. After 3 and 5 days, higher numbers of cells were observed specifically in HPL/Fibrin 1. A higher expression of Na+/K+-ATPase, ZO-1 and vimentin proteins was detected in the HPL/Fibrin 1-cultured HCECs as compared with control (no scaffold). HPL/Fibrin can be used as a suitable scaffold for HCECs while preserving the cells viability. Further investigations are necessitated to approve the beneficial effects of the suggested scaffold for delivering and transplantation of cultivated HCECs into the anterior chamber of the eye.

Epicardial placement of human MSC-loaded fibrin sealant films for heart failure: Preclinical efficacy and mechanistic data

Mesenchymal stromal cell (MSC) transplantation has been investigated as an advanced treatment of heart failure; however, further improvement of the therapeutic efficacy and mechanistic understanding are needed. Our previous study has reported that epicardial placement of fibrin sealant films incorporating rat amniotic membrane-derived (AM)-MSCs (MSC-dressings) could address limitations of traditional transplantation methods. To progress this finding toward clinical translation, this current study aimed to examine the efficacy of MSC-dressings using human AM-MSCs (hAM-MSCs) and the underpinning mechanism for myocardial repair. Echocardiography demonstrated that cardiac function and structure were improved in a rat ischemic cardiomyopathy model after hAM-MSC-dressing therapy. hAM-MSCs survived well in the rat heart, enhanced myocardial expression of reparative genes, and attenuated adverse remodeling. Copy number analysis by qPCR revealed that upregulated reparative genes originated from endogenous rat cells rather than hAM-MSCs. These results suggest hAM-MSC-dressing therapy stimulates a secondary release of paracrine factors from endogenous cells improving myocardial repair (“secondary paracrine effect”), and cardiac M2-like macrophages were identified as a potential cell source of repair. We demonstrated hAM-MSCs increased M2-like macrophages through not only enhancing M2 polarization but also augmenting their proliferation and migration capabilities via PGE2, CCL2, and TGF-β1, resulting in enhanced cardiac function after injury.

Human Cadaveric Donor Cornea Derived Extra Cellular Matrix Microparticles for Minimally Invasive Healing/Regeneration of Corneal Wounds.

Biological materials derived from extracellular matrix (ECM) proteins have garnered interest as their composition is very similar to that of native tissue. Herein, we report the use of human cornea derived decellularized ECM (dECM) microparticles dispersed in human fibrin sealant as an accessible therapeutic alternative for corneal anterior stromal reconstruction. dECM microparticles had good particle size distribution (≤10 µm) and retained the majority of corneal ECM components found in native tissue. Fibrin–dECM hydrogels exhibited compressive modulus of 70.83 ± 9.17 kPa matching that of native tissue, maximum burst pressure of 34.3 ± 3.7 kPa, and demonstrated a short crosslinking time of ~17 min. The fibrin–dECM hydrogels were found to be biodegradable, cytocompatible, non-mutagenic, non-sensitive, non-irritant, and supported the growth and maintained the phenotype of encapsulated human corneal stem cells (hCSCs) in vitro. In a rabbit model of anterior lamellar keratectomy, fibrin–dECM bio-adhesives promoted corneal re-epithelialization within 14 days, induced stromal tissue repair, and displayed integration with corneal tissues in vivo. Overall, our results suggest that the incorporation of cornea tissue-derived ECM microparticles in fibrin hydrogels is non-toxic, safe, and shows tremendous promise as a minimally invasive therapeutic approach for the treatment of superficial corneal epithelial wounds and anterior stromal injuries.

Thrombin- and plasmin-like and platelet-aggregation-inducing activities of Plumeria alba L. latex: Action of cysteine protease

Ethnopharmacological relevanceIn folk medicine, parts of Plumeria alba L. are used for the treatment of many diseases, with its latex being used for curing skin diseases and promoting wound healing. Aim of the studyThis study aimed to study the role of P. alba L. latex in hemostasis and platelet aggregation. Materials and methodsThe latex of P. alba L. was processed to remove waxes and enrich protein content, and the final extract was named Plumeria alba L. natant latex (PaNL). PaNL was analyzed for protease activity against casein. The type of protease in PaNL was identified by using protease inhibitors such as E−64, phenylmethylsulfonyl fluoride, ethylenediaminetetraacetic acid, and pepstatin A. Human fibrinogen, fibrin, and collagen types I and IV were subjected to hydrolysis with different concentrations of PaNL. The thrombin-like activity of PaNL was determined by analyzing its fibrinogen-clotting and procoagulant activities. The role of PaNL in platelet aggregation was also investigated. Its hemorrhagic and edema-inducing activities were evaluated in a mouse model. Phytochemical compounds were identified by gas chromatography–mass spectroscopy. ResultsThe findings of casein/gelatin zymography confirmed that PaNL possesses protease activity. The results of the protease inhibition study indicated the presence of a cysteine-type protease(s) in PaNL. PaNL hydrolyzed the subunits of fibrinogen, fibrin, and collagen types I and IV. Its fibrin-degradation activity indicated that PaNL possesses plasmin-like activity. PaNL induced clotting of citrated human plasma within 3 min of incubation in the absence of CaCl2, indicating the presence of thrombin-like activity, which was further confirmed by the results of the fibrinogen-clotting assay. PaNL induced platelet aggregation in the absence of agonists. There was no hemolytic activity. Mice injected with PaNL did not show edema/ hemorrhagic activity. ConclusionPaNL possesses procoagulant, fibrino(geno)lytic, thrombin- and plasmin-like activities and induces platelet aggregation, which could explain its usage for wound treatment in folk medicine.