Clinical evaluations of complete autologous fibrin glue, produced by the CryoSeal ® FS system, and polyglycolic acid sheets as wound coverings after oral surgery

The hemostatic and comforting effects of oral adhesive bandages in tooth extraction: a randomized controlled clinical study

OBJECTIVES

To compare oral adhesive bandages with the classic compression method and evaluate the clinical efficacy of this wound dressing material in improving postoperative comfort, wound healing, and hemostasis in tooth extraction.

MATERIALS AND METHODS

The study was designed as a randomized controlled clinical trial. A total of 120 patients were recruited and randomly assigned to the study group and the control group. In the study group, oral adhesive bandages were used as wound dressing. In the control group, patients bit on cotton balls and gauze, as usual. Hemorrhage, comfort, and healing levels were evaluated at postoperative 1 h, 24 h, and 7 days. The adhesion time of the oral adhesive bandages was also recorded.

RESULTS

The average adhesion time of the oral adhesive bandages was 26.6 h. At postoperative 1 and 24 h, the hemostatic levels of the oral adhesive bandage group were significantly higher than those of the control group. The oral adhesive bandage group also reported significantly higher comfort scores than the control group. Both groups had similar healing levels and side effects. But the mean score for wound healing was slightly higher in the oral adhesive bandage group.

CONCLUSIONS

Oral adhesive bandages were more effective than cotton balls and gauze in providing hemostatic and comfort effects on extraction wounds.

CLINICAL RELEVANCE

Oral adhesive bandages possess clinical value in the management of extraction wounds.

Novel Strategies for Orofacial Soft Tissue Regeneration

Significance: Orofacial structures are indispensable for speech and eating, and impairment disrupts whole-body health through malnutrition and poor quality of life. However, due to the unique and highly specialized cell populations, tissue architecture, and healing microenvironments, regeneration in this region is challenging and inadequately addressed to date. Recent Advances: With increasing understanding of the nuanced physiology and cellular responses of orofacial soft tissue, novel scaffolds, seeded cells, and bioactive molecules were developed in the past 5 years to specifically target orofacial soft tissue regeneration, particularly for tissues primarily found within the orofacial region such as oral mucosa, taste buds, salivary glands, and masseter muscles. Critical Issues: Due to the tightly packed and complex anatomy, orofacial soft tissue injury commonly implicates multiple tissue types, and thus functional unit reconstruction in the orofacial region is more important than single tissue regeneration. Future Directions: This article reviews the up-to-date knowledge in this highly translational topic, which provides insights into novel biologically inspired and engineered strategies for regenerating orofacial component tissues and functional units.

Secondary healing property using Neoveil®, a polyglycolic acid bioabsorbable sheet on the oral mucosal defects

Neoveil® is a wound surface-covering agent composed of polyglycolic acid(PGA) effective for secondary healing. This study evaluated the secondary healing property of oral cavity mucosal defects using the PGA sheet. Thirty-four patients who underwent surgical excision of oral benign and malignant lesions, precancerous lesions, and tumors were evaluated. The PGA sheet was placed over the open wound to aid secondary healing. The defects were reviewed post-operatively for secondary healing, contracture, and secondary deformity. Male to female ratio was 20:14, and the mean age was 63.5 years. In all cases, the oral mucosal defect was present after the wide excision of the mucosal lesion. The PGA sheet was used as a surface covering agent which was found to be effective in secondary healing of the wound. Any side effects and adverse reactions which were caused by the PGA sheet was not evident. It can be used to avoid skin graft or free flap reconstruction or deformity from the direct closure in moderate size oral mucosal defect.

Clinical Feasibility of Completely Autologous Fibrin Glue in Spine Surgery

Introduction

Fibrin glue is widely used in spine surgery. Nevertheless, no report has demonstrated the feasibility of completely autologous fibrin glue (CAFG) in spine surgery. This study aims to investigate the safety, efficacy, and effect of bone fusion of CAFG on spine surgery.

Methods

We retrospectively extracted data of patients who underwent primary spine surgery with preoperatively prepared CAFG. Primary outcomes were the incidence of wound-related unplanned reoperations within 90 days following primary surgery and the occurrence of reoperation for the management of cerebrospinal fluid (CSF) leakage in patients who had been treated with CAFG used as dural sealants. The effect of CAFG on bone fusion was also assessed by detecting implant failure at one year postoperatively in patients aged 25 years or less undergoing primary fusion for idiopathic scoliosis.

Results

We identified 131 eligible patients (47 males and 84 females) with a mean age of 32.3 years. CAFG was used most frequently as an adhesive for fixation of graft bone (110 patients), followed by as a dural sealant for CSF leakage in 17 patients, and as a local hemostatic agent in four patients. Wound-related reoperations were identified in four patients (3.1%), which included three for surgical site infection, and one for postoperative epidural hematoma. There was no reoperation required for the management of CSF leakage among 17 patients with dural incision or incidental durotomy. Compared with the control cohort, the use of CAFG was not associated with early wound-related reoperations or implant failure in patients with spinal deformity.

Conclusions

We demonstrated the clinical feasibility of CAFG in spine surgery. The use of CAFG was not associated with the incidence of reoperations for wound-related complications. CAFG worked effectively as a dural sealant for preventing CSF leakage. CAFG had no beneficial or adverse effect on spinal bone fusion.

Harnessing Multifaceted Next-Generation Technologies for Improved Skin Wound Healing

Dysregulation of sequential and synchronized events of skin regeneration often results in the impairment of chronic wounds. Conventional wound dressings fail to trigger the normal healing mechanism owing to the pathophysiological conditions. Tissue engineering approaches that deal with the fabrication of dressings using various biomaterials, growth factors, and stem cells have shown accelerated healing outcomes. However, most of these technologies are associated with difficulties in scalability and cost-effectiveness of the products. In this review, we survey the latest developments in wound healing strategies that have recently emerged through the multidisciplinary approaches of bioengineering, nanotechnology, 3D bioprinting, and similar cutting-edge technologies to overcome the limitations of conventional therapies. We also focus on the potential of wearable technology that supports complete monitoring of the changes occurring in the wound microenvironment. In addition, we review the role of advanced devices that can precisely enable the delivery of nanotherapeutics, oligonucleotides, and external stimuli in a controlled manner. These technological advancements offer the opportunity to actively influence the regeneration process to benefit the treatment regime further. Finally, the clinical relevance, trajectory, and prospects of this field have been discussed in brief that highlights their potential in providing a beneficial wound care solution at an affordable cost.

Wound healing effect of autologous fibrin glue and polyglycolic acid sheets in a rat back skin defect model

Fibrin glue from autologous plasma may prevent viral infection and allergic reaction. Moreover, this biomaterial contains growth factors such as TGF-β and VEGF that promote reconstruction of the mucous membrane by stimulating fibroblast proliferation and angiogenesis. Thus, autologous fibrin glue is predicted to improve healing better than commercial fibrin glue. Here, we evaluated the effects of autologous fibrin glue on the crucial early phase of wound healing. Epithelial defects were introduced in rats and covered with polyglycolic acid (PGA) sheets with or without commercial or autologous fibrin glue. Wound healing was assessed for six weeks by histology and immunohistochemistry. Our results demonstrate that wounds covered with PGA sheets and autologous fibrin glue achieved efficient wound healing without complications such as local infection or incomplete healing. The rate of recovery of the regenerating epithelium in this group was superior to that in wounds covered with PGA sheets and commercial fibrin glue. Immunohistochemistry of laminin, cytokeratin, and VEGF confirmed fine and rapid epithelial neogenesis. Collectively, our results indicate that covering surgical wounds with autologous fibrin glue promotes wound healing and epithelialization, improves safety, and reduces the risks of viral infection and allergic reaction associated with conventional techniques.

The development of a novel autologous blood glue aiming to improve osseointegration in the bone-implant interface

Aims

For cementless implants, stability is initially attained by an interference fit into the bone and osteo-integration may be encouraged by coating the implant with bioactive substances. Blood based autologous glue provides an easy, cost-effective way of obtaining high concentrations of growth factors for tissue healing and regeneration with the intention of spraying it onto the implant surface during surgery. The aim of this study was to incorporate nucleated cells from autologous bone marrow (BM) aspirate into gels made from the patient’s own blood, and to investigate the effects of incorporating three different concentrations of platelet rich plasma (PRP) on the proliferation and viability of the cells in the gel.

Methods

The autologous blood glue (ABG) that constituted 1.25, 2.5, and 5 times concentration PRP were made with and without equal volumes of BM nucleated cells. Proliferation, morphology, and viability of the cells in the glue was measured at days 7 and 14 and compared to cells seeded in fibrin glue.

Results

Overall, 2.5 times concentration of PRP in ABG was capable of supporting the maximum growth of cells isolated from the BM aspirate and maintain their characteristics. Irrespective of PRP concentration, cells in ABG had statistically significantly higher viability compared to cells in fibrin glue.

Conclusion

In vitro this novel autologous gel is more capable of supporting the growth of cells in its structure for up to 14 days, compared to commercially available fibrin-based sealants, and this difference was statistically significant.

Cite this article: Bone Joint Res 2020;9(7):402–411.

Comparison and application of commercially available fibrin sealants in ophthalmology

Fibrin glues carry many advantages over traditional suture as a tissue adhesive and have been increasingly used in a variety of ophthalmic procedures over the past 15 years. Several fibrin sealants are commercially available worldwide, each of which differs slightly in its composition and mechanism of delivery. The focus of our review is to briefly discuss the reported uses of fibrin in ophthalmic surgery and provide a broad overview of the properties associated with each commercially available fibrin sealant.

Feasibility of autologous fibrin glue in general thoracic surgery

Background

Fibrin glue effectively controls air leakage in lung surgery; however, allogenic fibrin glue cannot eliminate the risks of infection and allergy despite current sterilization methods. Autologous fibrin glue (AFG) could be a good alternative, but is not commonly used worldwide because of its limited availability and lack of evidence. Herein, we report clinical outcomes of AFG in thoracic surgery.

Methods

We retrospectively analyzed patients who underwent lobectomies or segmentectomies between November 2016 and September 2017 in our institution. We used two types of AFGs. One was a partially-autologous fibrin glue (PAFG), the components of which are largely autologous but which contains allogenic thrombin. The other was a completely-autologous fibrin glue (CAFG) which has no allogenic components. PAFG was used in the first half of the study period, after which CAFG was used from March 2017 onward. Patients who did not undergo AFG generation were categorized as the non-AFG group. The perioperative outcomes of the three groups were evaluated.

Results

A total of 207 patients underwent lung surgery, including 118 lobectomies and 89 segmentectomies. Among them, 83 patients received PAFG, 94 received CAFG, and 30 received non-AFG. The mean postoperative drainage period was within a few days in each group (PAFG vs. CAFG vs. non-AFG: 3.23±3.91 vs. 3.16±4.04 vs. 3.17±4.16 days, respectively; P=0.405), and the incidence of postoperative prolonged air leakage was within an acceptable range (PAFG vs. CAFG vs. non-AFG: 13.3% vs. 12.8% vs. 16.7%, respectively; P=0.821).

Conclusions

The use of AFG is clinically feasible for patients who undergo lobectomies or segmentectomies. AFGs could be a viable alternative to conventional allogenic fibrin glues.

Human Fibrinogen for Maintenance and Differentiation of Induced Pluripotent Stem Cells in Two Dimensions and Three Dimensions

Human fibrin hydrogels are a popular choice for use as a biomaterial within tissue engineered constructs because they are biocompatible, nonxenogenic, autologous use compatible, and biodegradable. We have recently demonstrated the ability to culture induced pluripotent stem cell (iPSC)‐derived retinal pigment epithelium on fibrin hydrogels. However, iPSCs themselves have relatively few substrate options (e.g., laminin) for expansion in adherent cell culture for use in cell therapy. To address this, we investigated the potential of culturing iPSCs on fibrin hydrogels for three‐dimensional applications and further examined the use of fibrinogen, the soluble precursor protein, as a coating substrate for traditional adherent cell culture. iPSCs successfully adhered to and proliferated on fibrin hydrogels. The two‐dimensional culture with fibrinogen allows for immediate adaption of culture models to a nonxenogeneic model. Similarly, multiple commercially available iPSC lines adhered to and proliferated on fibrinogen coated surfaces. iPSCs cultured on fibrinogen expressed similar levels of the pluripotent stem cell markers SSea4 (98.7% ± 1.8%), Oct3/4 (97.3% ± 3.8%), TRA1‐60 (92.2% ± 5.3%), and NANOG (96.0% ± 3.9%) compared with iPSCs on Geltrex. Using a trilineage differentiation assay, we found no difference in the ability of iPSCs grown on fibrinogen or Geltrex to differentiate to endoderm, mesoderm, or ectoderm. Finally, we demonstrated the ability to differentiate iPSCs to endothelial cells using only fibrinogen coated plates. On the basis of these data, we conclude that human fibrinogen provides a readily available and inexpensive alternative to laminin‐based products for the growth, expansion, and differentiation of iPSCs for use in research and clinical cell therapy applications. stem cells translational medicine2019;8:512–521

Fibrin hydrogels as a xenofree and rapidly degradable support for transplantation of retinal pigment epithelium monolayers

Recent phase 1 trials of embryonic stem cell and induced pluripotent stem cell (iPSCs) derived RPE transplants for the treatment of macular degeneration have demonstrated the relative safety of this process. However, there is concern over clumping, thickening, folding, and wrinkling of the transplanted RPE. To deliver a flat RPE monolayer, current phase 1 trials are testing synthetic substrates for RPE transplantation. These substrates, however, cause localized inflammation and fibrosis in animal models due to long degradation times. Here we describe the use of thin fibrin hydrogels as a support material for the transplantation of RPE. Fibrin was formed into a mechanically rigid support that allow for easy manipulation with standard surgical instruments. Using fibrinolytic enzymes, fibrin hydrogels were degraded on the scale of hours. The rate of degradation could be controlled by varying the fibrinolytic enzyme concentration used. RPE cells degraded fibrin spontaneously. To preserve the fibrin support during differentiation of iPSCs to RPE, media was supplemented with the protease inhibitor aprotinin. iPSC-RPE on fibrin gels remained viable, generated monolayers with characteristic cobblestone appearance and dark pigmentation, and expressed mRNA and protein markers characteristic of RPE in the eye. Following differentiation of the cells, addition of fibrinolytic enzymes fully and rapidly degraded the fibrin support leaving behind an intact, viable iPSC-RPE monolayer. In conclusion, human fibrin hydrogels provide a xeno-free support on which iPSCs can be differentiated to RPE cells for transplant which can be rapidly degraded under controlled conditions using fibrinolytic enzymes without adverse effects to the cells.

STATEMENT OF SIGNIFICANCE

Stem cell-derived retinal pigment epithelial (RPE) cell transplantation is currently in phase 1 clinical trials for macular degeneration (MD). A major obstacle in these studies is delivering the RPE as a living, flat sheets without leaving behind foreign materials in the retina. Here we investigate the suitability of using hydrogels made from human blood-derived proteins for RPE transplant. Our data shows that these fibrin hydrogels are rigid enough for use in surgery, support growth of stem cell-derived RPE, and are easily degraded within hours without damage to the RPE sheet. These fibrin hydrogels offer a promising solution to transplant RPE for patients with MD.