Electron-Beam Irradiated Recombinant Human Collagen-Phosphorylcholine Corneal Implants Retain Pro-Regeneration Capacity.

Sterilization of biodegradable, collagen-based implants is challenging as irradiation sterilization methods can alter their mechanical properties. Electron beam (EB) irradiation is a terminal sterilization method that has been used for biologically-derived implants. Here, recombinant human collagen type III-phosphorylcholine (RHCIII-MPC) hydrogels were irradiated with EB doses of 17, 19, or 21 kGy and their subsequent biocompatibility and ability to promote regeneration in rabbit corneas was evaluated.

Collagen-based scaffolds with infused anti-VEGF release system as potential cornea substitute for high-risk keratoplasty: A preliminary in vitro evaluation.

Currently the only widely accepted corneal blindness treatment is human donor cornea transplantation. However, increasing shortage of donor corneas as well as high risk of rejection in some corneal diseases remain two major problems, which limit the success of corneal transplantation. Corneal neovascularization is considered as one of the main risk factors of graft failure.

LiQD Cornea: Pro-regeneration collagen mimetics as patches and alternatives to corneal transplantation.

Transplantation with donor corneas is the mainstay for treating corneal blindness, but a severe worldwide shortage necessitates the development of other treatment options. Corneal perforation from infection or inflammation is sealed with cyanoacrylate glue. However, the resulting cytotoxicity requires transplantation.

Biomaterials-enabled cornea regeneration in patients at high risk for rejection of donor tissue transplantation.

The severe worldwide shortage of donor organs, and severe pathologies placing patients at high risk for rejecting conventional cornea transplantation, have left many corneal blind patients untreated. Following successful pre-clinical evaluation in mini-pigs, we tested a biomaterials-enabled pro-regeneration strategy to restore corneal integrity in an open-label observational study of six patients. Cell-free corneal implants comprising recombinant human collagen and phosphorylcholine were grafted by anterior lamellar keratoplasty into corneas of unilaterally blind patients diagnosed at high-risk for rejecting donor allografts.

Collagen-Based Fillers as Alternatives to Cyanoacrylate Glue for the Sealing of Large Corneal Perforations.

Purpose: To describe the use of collagen-based alternatives to cyanoacrylate glue for the sealing of acute corneal perforations.

Methods: A collagen analog comprising a collagen-like peptide conjugated to polyethylene glycol (CLP-PEG) and its chemical crosslinker were tested for biocompatibility. These CLP-PEG hydrogels, which are designed to act as a framework for corneal tissue regeneration, were then tested as potential fillers in ex vivo human corneas with surgically created full-thickness perforations.

Hyperelastic Nanocellulose-Reinforced Hydrogel of High Water Content for Ophthalmic Applications.

A nanocellulose-reinforced poly(vinyl alcohol) hydrogel material of exceptionally high water content for ophthalmic applications is presented (>90 wt %), which also features a hitherto unprecedented combination of optical, mechanical, viscoelastic, oxygen permeability, and biocompatibility properties. The hydrogel combines the desired softness with remarkable strain-dependent mechanical strength and thereby demonstrates hyperelastic, rubber-like mechanical properties. The observed unusual mechanical behavior is due to both high water content and the combination of relatively stiff cellulose nanowhiskers entangled in a soft polymer matrix of poly(vinyl alcohol) (PVA), thus mimicking the structural characteristics of the cornea's main constituents, i.

The Quest for Anti-inflammatory and Anti-infective Biomaterials in Clinical Translation.

Biomaterials are now being used or evaluated clinically as implants to supplement the severe shortage of available human donor organs. To date, however, such implants have mainly been developed as scaffolds to promote the regeneration of failing organs due to old age or congenital malformations. In the real world, however, infection or immunological issues often compromise patients.

Bioengineered Corneas Grafted as Alternatives to Human Donor Corneas in Three High-Risk Patients.

Corneas with severe pathologies have a high risk of rejection when conventionally grafted with human donor tissues. In this early observational study, we grafted bioengineered corneal implants made from recombinant human collagen and synthetic phosphorylcholine polymer into three patients for whom donor cornea transplantation carried a high risk of transplant failure. These patients suffered from corneal ulcers and recurrent erosions preoperatively.

Cathelicidin LL-37 and HSV-1 Corneal Infection: Peptide Versus Gene Therapy.

Purpose: To evaluate the potential utility of collagen-based corneal implants with anti-Herpes Simplex Virus (HSV)-1 activity achieved through sustained release of LL-37, from incorporated nanoparticles, as compared with cell-based delivery from model human corneal epithelial cells (HCECs) transfected to produce endogenous LL-37.

Methods: We tested the ability of collagen-phosphorylcholine implants to tolerate the adverse microenvironment of herpetic murine corneas. Then, we investigated the efficacy of LL-37 peptides delivered through nanoparticles incorporated within the corneal implants to block HSV-1 viral activity.

Amniotic membrane transplantation in treatment of persistent corneal ulceration after severe chemical and thermal eye injuries.

Purpose: To analyze results of amniotic membrane transplantation (AMT) in treatment of corneal ulceration after severe chemical and thermal injuries.

Methods: Analysis of 55 AMT in 53 patients (53 eyes) with corneal ulceration and limbal deficiency 180-360° of the limbus after grade 4-6 (Dua classification, 2001) chemical and thermal injuries was performed. Mean terms of the operation were 46.

Collagen-based bioengineered substitutes of donor corneal allograft implantation: assessment and hypotheses.

To fabricate donor corneal substitutes based on carbodiimide cross-linked porcine collagen, to study their in vitro and in vivo properties, and to elaborate new implantation techniques for the donor corneal collagen-based substitutes, this study had been performed. Bioengineered substitutes of corneal stroma (BSCS) were fabricated by cross-linking porcine type I collagen with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide and N-hydroxysuccinimide, as previously described. Their refractive indices were measured using an Abbe refractometer.

Treatment of post-burn persistent corneal ulcers with excimer laser phototherapeutic keratectomy. Prospective clinical trial.

Purpose: To evaluate efficacy of excimer laser phototherapeutic keratectomy (PTK) i n treatment of patients with post-burn persistent corneal ulcers.

Material And Methods: Study design--nonrandomized trial with a "historic" control group. 54 eyes (53 patient) with central superficial post-burn corneal ulcers that were formed in different time frame (18-104 days) after grade IV burns were included into the study.

Healing of alkali burned rabbit corneas with persistent superficial ulceration after excimer laser phototherapeutic keratectomy. Clinical and electron microscopic findings.

Purpose: To evaluate epithelial and stromal healing of kakali-bumed rabbit corneas with persistent superficial ulceration after phototherapeutic keratectomy (PTK).

Material And Methods: 36 rabbits (36 eyes), with superficial corneal ulcers, which were formed after 10% NaOH corneal burn, were used. PTK was performed on the 18th day after the burn in 18 rabbits.