Regenerative approaches for the cornea.

The cornea is the transparent front part of the eye that transmits light to the back of the eye to generate vision. Loss of corneal transparency, if irreversible, leads to severe vision loss or blindness. For decades, corneal transplantation using human donor corneas has been the only option for treating corneal blindness. Despite recent improvement in surgical techniques, donor cornea transplantation remains plagued by risks of suboptimal optical results and visual acuity, immune rejection and eventually graft failure. Furthermore, the demand for suitable donor corneas is increasing faster than the number of donors, leaving thousands of curable patients untreated worldwide. Here, we critically review the state of the art of biomaterials for corneal regeneration. However, the lessons learned from the use of the cornea as a disease model will allow for extension of the biomaterials and techniques for regeneration of more complex organs such as the heart.

Nitroxide amide-BODIPY probe behavior in fibroblasts analyzed by advanced fluorescence microscopy.

A novel synthesized nitroxide amide-BODIPY prefluorescent probe was used to study cellular redox balance that modulates nitroxide/hydroxylamine ratio in cultured human fibroblasts. FLIM quantitatively differentiated between nitroxide states of the cytoplasm-localized probe imaged by TIRF, monitoring nitroxide depletion by hydrogen peroxide; eluding incorrect interpretation if only fluorescence intensity is considered.

Novel specific peptides as superior surface stabilizers for silver nano structures: role of peptide chain length.

Three new collagen mimetic peptides containing the CLK motif as anchoring arms were tested for silver nanoparticle surface stabilization. Our experimental and molecular dynamics data indicate that peptide length has an important effect not only in the resulting nanosilver's colloidal stability, but also in the biological performance of the composite.

Correction: Functionalised type-I collagen as a hydrogel building block for bio-orthogonal tissue engineering applications.

Correction for 'Functionalised type-I collagen as a hydrogel building block for bio-orthogonal tissue engineering applications' by R. Ravichandran et al., J. Mater. Chem. B, 2016, 4, 318-326.

Coloured cornea replacements with anti-infective properties: expanding the safe use of silver nanoparticles in regenerative medicine.

Despite the broad anti-microbial and anti-inflammatory properties of silver nanoparticles (AgNPs), their use in bioengineered corneal replacements or bandage contact lenses has been hindered due to their intense yellow coloration. In this communication, we report the development of a new strategy to pre-stabilize and incorporate AgNPs with different colours into collagen matrices for fabrication of corneal implants and lenses, and assessed their in vitro and in vivo activity.

Functionalised type-I collagen as a hydrogel building block for bio-orthogonal tissue engineering applications.

In this study, we derivatized type I collagen without altering its triple helical conformation to allow for facile hydrogel formation via the Michael addition of thiols to methacrylates without the addition of other crosslinking agents. This method provides the flexibility needed for the fabrication of injectable hydrogels or pre-fabricated implantable scaffolds, using the same components by tuning the modulus from Pa to kPa. Enzymatic degradability of the hydrogels can also be easily fine-tuned by variation of the ratio and the type of the cross-linking component. The structural morphology reveals a lamellar structure mimicking native collagen fibrils. The versatility of this material is demonstrated by its use as a pre-fabricated substrate for culturing human corneal epithelial cells and as an injectable hydrogel for 3-D encapsulation of cardiac progenitor cells.