Ranjithkumar Ravichandran

New Insights into Peptide–Silver Nanoparticle Interaction: Deciphering the Role of Cysteine and Lysine in the Peptide Sequence

We studied the interaction of four new pentapeptides with spherical silver nanoparticles. Our findings indicate that the combination of the thiol in Cys and amines in Lys/Arg residues is critical to providing stable protection for the silver surface. Molecular simulation reveals the atomic scale interactions that underlie the observed stabilizing effect of these peptides, while yielding qualitative agreement with experiment for ranking the affinity of the four pentapeptides for the silver surface.

Applications of self-assembling peptide scaffolds in regenerative medicine: the way to the clinic

Peptides that self-assemble into well-defined nanofibrous networks provide a prominent alternative to traditional biomaterials for fabricating scaffolds for use in regenerative medicine and other biomedical applications. Such scaffolds can be generated by decorating a peptide backbone with other bioactives such as cell specific adhesion peptides, growth factors and enzyme cleavable sequences. They can be designed to mimic the three-dimensional (3D) structural features of native ECM and can therefore also provide insight into the ECM-cell interactions needed for development of scaffolds that can serve as regeneration templates for specific target tissues or organs. This review highlights the potential application of self-assembling peptides in regenerative medicine.

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.

Self-assembled collagen-like-peptide implants as alternatives to human donor corneal transplantation

Extracellular matrix proteins like collagen promote regeneration as implants in clinical studies. However, collagens are large and unwieldy proteins, making small functional peptide analogs potenti ...

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.

Type I Collagen-Derived Injectable Conductive Hydrogel Scaffolds as Glucose Sensors

The advent of home blood glucose monitoring revolutionized diabetes management, and the recent introduction of both wearable devices and closed-loop continuous systems has enormously impacted the lives of people with diabetes. We describe the first fully injectable soft electrochemical glucose sensor for in situ monitoring. Collagen, the main component of a native extracellular matrix in humans and animals, was used to fabricate an in situ gellable self-supporting electroconductive hydrogel that can be injected onto an electrode surface or into porcine meat to detect glucose amperometrically. The study provides a proof-of-principle of an injectable electrochemical sensor suitable for monitoring tissue glucose levels that may, with further development, prove clinically useful in the future.