fibrin and Corneal-Diseases

The only cultured cell types extensively used for tissue regeneration are the keratinocyte and the chondrocyte. Cultured autologous keratinocytes derived from the epidermis have been used for many years to produce grafts that regenerate an epidermis over a full-thickness wound, such as a third-degree burn. But there have been many failures of engraftment, and in the absence of criteria for the quality of the cultures, the causes of failure cannot be analyzed. It has become clear that the essential feature of the graft is the presence of an adequate number of stem cells. This article describes the criteria for estimating that number. Advances in graft preparation, combining better preservation of stem cells with ease of application of the graft, are also described. These improvements have been applied to cultures of ocular limbal cells, which contain the keratinocyte stem cells of the corneal epithelium. Cultures meeting the criteria of stem cell number have been grafted to 116 patients suffering from chemical destruction of the limbus. The procedure has been highly successful in the alleviation of suffering and the restoration of vision.

Topics: Animals; Cells, Cultured; Corneal Diseases; Epidermis; Epithelium; Epithelium, Corneal; Fibrin; Humans; Keratinocytes; Limbus Corneae; Melanocytes; Membrane Proteins; Models, Biological; Organ Culture Techniques; Regeneration; Stem Cell Transplantation; Stem Cells; Transplantation, Autologous; Urethra

Endothelial plaque is an important sign of fungal keratitis and is related to diagnosis, surgical indications, and prognosis. However, bacterial keratitis sometimes involves fibrin formation on the back corneal surface, similar to endothelial plaques. Because corneal infiltration interferes with precise observation of the posterior corneal plaque, distinguishing pathogens with a slitlamp is difficult. We hope to assist clinicians in early diagnosis and timely treatment by observing the connection state of endothelial plaques and the corneal endothelium through anterior segment optical coherence tomography (AS-OCT) and the different forms of endothelial plaques in infectious keratopathy through in vivo confocal microscopy (IVCM).. We analyzed 52 patients in the Eye Hospital of the First Affiliated Hospital of Harbin Medical University who were clearly diagnosed with fungal or bacterial keratitis with endothelial plaques. All patients underwent AS-OCT and IVCM on admission.. According to the smear, IVCM, or fungal and bacterial culture results, the patients were diagnosed with fungal (28 patients) or bacterial keratitis (24 patients). AS-OCT in 25 patients diagnosed with fungal keratitis revealed that the corneal endothelium-endothelial plaque boundary was unclear and wavy, and 24 patients had unclear cell boundaries and a large number of compactly distributed inflammatory cells in the endothelial layer according to IVCM. AS-OCT in 23 patients diagnosed with bacterial keratitis revealed clear corneal endothelium-endothelial plaque boundaries, and insufficient endothelial cell boundaries with a large number of visible and scattered inflammatory cell structures were observed through IVCM in 22 patients.. Corneal endothelial plaque detection by AS-OCT and IVCM can be used for early diagnosis of infectious keratitis.

Topics: Corneal Diseases; Corneal Ulcer; Eye Infections, Bacterial; Eye Infections, Fungal; Fibrin; Humans; Keratitis; Microscopy, Confocal; Tomography, Optical Coherence; Vision Disorders

To evaluate the safety and efficacy of the surgical use of autologous plasma rich in growth factors fibrin membrane (mPRGF) in improving corneal wound healing and regeneration in a variety of complex ocular surface defects.. Chart review on 15 eyes of 14 included patients undergoing ocular surface intervention using intraoperative mPRGF at the Bascom Palmer Eye Institute and at the Instituto Oftalmológico Fernández-Vega was performed. Patients were grouped based on type of intervention or condition (penetrating keratoplasty, superficial keratectomy, neurotrophic or persistent corneal ulcers, and corneal perforation). Patients were followed for an average of 11 ± 5 months. Main outcomes measured were mPRGF dissolving time, best-corrected visual acuity, and evidence of any persistent epithelial defects, rejections, or complications.. All 15 eyes underwent successful placement of mPRGF. Average dissolving time for fibrin membrane was 21 ± 3 days. mPRGF resulted in total healing of the corneal defects in 13/15 (86.7%) of the treated eyes and partial healing in 2/15 (13.3%) eyes in which persistent epithelial defects were noted on follow-up. Visual acuity improvement was seen in 9/15 (60%) of the cases.. The use of autologous mPRGF in the healing and regeneration of the ocular surface is a secure and efficacious surgical option. Our data demonstrate that PRGF fibrin membrane should be contemplated as an important tool to optimize ocular surface regeneration in complex cases.

Topics: Corneal Diseases; Corneal Ulcer; Eye Diseases; Fibrin; Humans; Intercellular Signaling Peptides and Proteins; Wound Healing

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.

Topics: Animals; Cadaver; Cell Proliferation; Cornea; Corneal Diseases; Extracellular Matrix; Fibrin; Humans; Hydrogels; Rabbits; Stem Cell Transplantation; Stem Cells; Tissue Engineering; Wound Healing

To develop a clinical grade fibrin gel for the culture of oral mucosal epithelial cells (OMEC) intended for ocular surface reconstruction in the treatment of limbal stem cell deficiency (LSCD).. Transparent fibrin gels composed of fibrinogen and thrombin were developed for the culture of epithelial cells. Oral mucosa was harvested from the buccal region of healthy volunteers and cultured as explants on fibrin gels. Tranexamic acid (TA), a clinically approved anti-fibrinolytic agent was added to prevent the fibrin gel from digesting due to cellular activity. The gels were stained for p63α (as a marker of poorly differentiated epithelial cells), CK19, CK13 and CK3 (expressed by OMEC). Epithelial cell stratification was observed using hematoxylin-eosin staining.. Addition of TA prevented gels from dissolving during the culture period. OMEC proliferated on the fibrin gel and attained confluence over a 2-week period (±2 d) and exhibited a typical epithelial, cobblestone morphology. Basal OMEC exhibited positive staining for p63α while the superficial cells exhibited positive staining for CK3. The cells expressed a strong immunoreactivity for CK19 and CK13 suggesting that they retained a normal oral epithelial phenotype.. Fibrin gels, maintained in the presence of TA, to control the rate of substrate degradation, provide a more robust yet transparent substrate for the culture and transplantation of cultured OMEC. The fibrin gels are easily standardized, the components commercially available, and produced from clinically approved materials. The resulting stratified OMEC-derived epithelium displays characteristics similar to that of a human cornea, e.g. CK3 expression. The conventional dependence on a murine feeder layer for support of epithelial cells is unnecessary with this technique and hence, provides for an attractive alternative for treatment of LSCD.

Topics: Adult; Antifibrinolytic Agents; Biomarkers; Cell Culture Techniques; Corneal Diseases; Epithelial Cells; Feeder Cells; Fibrin; Fluorescent Antibody Technique, Indirect; Gels; Humans; Keratin-13; Keratin-19; Keratin-3; Middle Aged; Mouth Mucosa; Plastic Surgery Procedures; Tissue Scaffolds; Tranexamic Acid; Transcription Factors; Tumor Suppressor Proteins

To compare the clinical results of cultivated oral mucosal epithelial cell sheet transplantation (COMET) of substrate-free sheets with those of COMET of amniotic membrane (AM)-based sheets.. Sixteen eyes receiving COMET of substrate-free sheets (substrate-free group) were studied retrospectively and compared with disease-, age-, and ocular surface status-matched eyes undergoing COMET with AM serving as the substrate (AM group). Each group consisted of six eyes with chemical injury, six with pseudo-ocular cicatricial pemphigoid, two with Stevens-Johnson syndrome, and two with ocular cicatricial pemphigoid. Graft survival rate, best-corrected visual acuity (BCVA), and neovascularization (NV) were assessed.. In all 32 eyes, the entire corneal surface on which the cultivated autologous oral mucosal epithelium sheet had been placed was free of epithelial defects at postoperative day 2. The success rates of COMET at 12 months after surgery were 62.5% in the substrate-free sheet group and 43.8% in the AM group. A Kaplan-Meier curve revealed that the graft survival rate in the substrate-free group was significantly superior to that in the AM group (P = 0.046). Mean postoperative BCVA improved significantly at 1, 3, and 6 months in the substrate-free sheet group, and BCVA was significantly better than that in the AM group at all time points. Postoperative NV improved significantly in the substrate-free group at all time points.. A better midterm clinical outcome was achieved with COMET of a substrate-free cell sheet than with COMET of AM as a substrate for treating severe stem cell deficiency.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Amnion; Case-Control Studies; Cell Culture Techniques; Cells, Cultured; Corneal Diseases; Epithelial Cells; Epithelium; Epithelium, Corneal; Female; Fibrin; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Mouth Mucosa; Retrospective Studies; Tissue Engineering; Tissue Scaffolds; Visual Acuity; Young Adult

Topics: Aged; Alkalies; Burns, Chemical; Cells, Cultured; Combined Modality Therapy; Corneal Diseases; Corneal Topography; Eye Burns; Fibrin; Humans; Lasers, Excimer; Limbus Corneae; Male; Photorefractive Keratectomy; Stem Cell Transplantation; Stem Cells; Transplantation, Autologous

To report a novel method of engineering transplantable, carrier-free corneal epithelial sheets by using a biodegradable fibrin sealant and to compare its characteristics with epithelial sheets cultivated on denuded amniotic membrane carriers.. Stratified corneal epithelial sheets were prepared in culture dishes coated with biodegradable fibrin glue. Amniotic membrane (AM) carriers served as the control. The quality of cultivated sheets was compared by immunohistochemistry for cytokeratin (K)3, K12, K14, p63, occludin, and integrin beta1; electron microscopy; and colony-forming assays. K3 protein expression was compared by Western blot analysis. In a limbal-deficient rabbit transplantation model, postoperative adaptation and proliferation of BrdU-labeled cell sheets were examined by histology and anti-Ki67 staining.. Epithelial sheets were successfully engineered by using a biodegradable fibrin sealant. Cell sheets in both groups were multilayered, expressed K3, K12, and K14, and had functioning occludin(+) apical tight junctions as well as p63 and integrin beta1 staining in basal cells. The carrier-free sheets appeared to be more differentiated than the AM sheets, which was also demonstrated by the higher levels of K3 in the Western blots. The colony-forming efficiency of dissociated cells was similar in both groups, although larger colonies were observed on the AM sheets. AM sheets retained higher levels of BrdU-labeled cells and fewer Ki67(+) cells compared with carrier-free sheets after transplantation.. Tissue engineering with a commercially available fibrin sealant was an effective means of creating a carrier-free, transplantable corneal epithelial sheet. Carrier-free sheets were more differentiated compared with AM sheets, while retaining similar levels of colony-forming progenitor cells.

Topics: 3T3 Cells; Amnion; Animals; Biomarkers; Blotting, Western; Bromodeoxyuridine; Cell Culture Techniques; Cell Differentiation; Cell Proliferation; Cell Transplantation; Coculture Techniques; Corneal Diseases; Epithelium, Corneal; Female; Fibrin; Fluorescent Antibody Technique, Indirect; Keratin-14; Keratin-3; Ki-67 Antigen; Mice; Rabbits; Stem Cells; Tissue Engineering

To study the results of transplantation of cultured autologous limbal stem cells using fibrin gel membrane as substrate for the treatment of limbal stem cell deficiency in rabbits.. An ocular surface defect was created in the right eyes of all rabbits by a lamellar keratectomy extending 1 mm outside the limbus. The stem cells were isolated from a small limbal biopsy specimen from the left eyes and cultured. Cells were grown over fibrin gel membrane to construct bioengineered corneal epithelium. After cytologic verification of total limbal stem cell deficiency, rabbits were divided into 4 groups at random. The fibrovascular pannus of each cornea was removed. Groups I - III (n = 24) underwent transplantation of limbus stem cells cultured on fibrin gel membrane and were observed for 3 months (Group I), 1 month (Group II) and 2 weeks (Group III), whereas group IV (n = 8) received only the fibrin gel membrane. Clinical outcome was graded by corneal integrity, opacity and neovascularization. HE staining, impression cytology and immunofluorescence staining with antibodies against keratin-3, MUC5AC and nuclear p63 were performed to assess the phenotype of corneal epithelium.. The cornea in the study groups (group I - III) recovered smoothly, covered with transparent epithelium and without neovascularization. In the control group (group IV), cornea was turbid and irregular, with neovascularization (P = 0.021). Corneal impression cytology indicated PAS (-) in the study groups, while PAS (+) in the control group. HE staining of the cornea in the study groups showed normal corneal phenotypes; whereas the epithelium cells in the control group showed conjunctival phenotypes with vessels and goblet cells. Immunostaining of study groups showed keratin-3 positive and MUC5AC negative corneal epithelium, and p63 was expressed in the basal cell of corneal epithelium. Cells in the control group expressed MUC5AC abundantly.. Tissue bioengineered cornea epithelium transplantation can successfully reconstruct corneal surface affected by limbal stem cell deficiency. Fibrin gel membrane is a new bioengineered material with the characteristics of absorbability, transparence and good histological compatibility. It is supposed to be an optimum stem cell scaffold.

Topics: Animals; Cells, Cultured; Corneal Diseases; Epithelium, Corneal; Female; Fibrin; Gels; Limbus Corneae; Male; Rabbits; Random Allocation; Stem Cell Transplantation; Stem Cells; Tissue Engineering

To describe an unusual ocular manifestation of a patient with acute myeloid leukemia (AML).. Observational case report.. A 59-year-old woman with a history of preleukemic myelodysplastic syndrome (MDS) and status post bone marrow transplant (BMT) complained of a sudden onset of poor vision associated with a corneal pseudomembrane. Ocular graft vs host disease was suspected, and the pseudomembrane was excised for histopathologic examination.. The pseudomembrane showed myeloblasts admixed with an acute inflammatory response suggestive of the development of AML, a complication of MDS. Bone marrow examination confirmed the diagnosis of relapsing AML.. Acute myeloid leukemia could present as a pseudomembrane; thus, examination of relevant ocular tissue is recommended.

Topics: Acute Disease; Bone Marrow; Bone Marrow Transplantation; Corneal Diseases; Female; Fibrin; Graft vs Host Disease; Humans; Leukemia, Myeloid; Membranes; Middle Aged; Neoplasm Recurrence, Local

Ligneous conjunctivitis is a rare form of chronic pseudomembranous conjunctivitis that is associated with systemic membranous pathological changes. A probable link between plasminogen and ligneous conjunctivitis has been indicated by the recent diagnoses of plasminogen deficiency in five patients suffering from ligneous conjunctivitis. The current study reports that plasminogen-deficient mice develop conjunctival lesions indistinguishable from human ligneous conjunctivitis in both appearance and histology. Both human and mouse lesions contain acellular material rich in fibrin, and aberrant or disrupted epithelium. The incidence of lesion development in mice increases with age and is strongly influenced by genetic background. Interestingly, ligneous conjunctivitis was not observed in plasminogen-deficient mice simultaneously lacking fibrinogen. This study provides direct evidence that plasminogen deficiency is one cause of ligneous conjunctivitis and suggests that plasminogen-deficient mice may be an excellent model for the development of therapeutic strategies for the treatment of this debilitating disease.

Topics: Aging; Animals; Conjunctivitis; Corneal Diseases; Epithelium; Female; Fibrin; Humans; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Plasminogen

This study confirms preliminary indications that dry-pack sterilized lenses cause a more marked anterior chamber reaction than wet-pack sterilized lenses during the immediate post-op period. After the first two weeks, this difference is not evident.

Topics: Aged; Anterior Chamber; Corneal Diseases; Edema; Ethylene Oxide; Eye Diseases; Female; Fibrin; Humans; Intraocular Pressure; Lenses, Intraocular; Male; Middle Aged; Postoperative Complications; Sodium Hydroxide; Sterilization; Time Factors; Visual Acuity

Topics: Burns; Cornea; Corneal Diseases; Disease; Fibrin; Humans; Wounds and Injuries