Gold nanorods as exogenous chromophores in the welding of ocular tissues

Abstract

In this paper we show for the first time the suitability of gold nanorods as exogenous chromophores to mediate the near infrared laser welding of connective tissues. We used a 810 nm diode laser to simulate hetero-transplantations of patches of porcine lens capsules stained with nanorods with plasmon resonances about that wavelength. In our preliminary tests, successful welding was achieved at fluences in the 80 -110 J·cm -2 range, which is, at worst, less than half of the threshold for direct damage, although still about a factor of two higher than the state-of-the-art with conventional chromophores such as Indocyanine Green.

Laser tissue welding in ophthalmic surgery

“…More recently, a new experimental study has been set up in order to verify the suitability of gold nanorods as exogenous chromophores to mediate the near infrared laser welding of ocular tissues [29]. This is outlined briefly in Section 4.2 as a promising perspective.…”

“…Gold nanoshells at silica nanospheres suspended in an albumin filler have been developed as a NIR activated solder to seal cutaneous and muscular lesions [50], with promising results. More recently we have exploited the exceptional performances of gold nanorods as NIR chromophores to weld patches of anterior lens capsules excised ex vivo from a porcine model (see Figure 10) [29].…”

Multifunctional Photonic Nanomaterials for Diagnostic, Therapeutic, and Theranostic Applications

“…Moreover, in line with the progress of material properties and functionalities, target‐specific phototherapy can be achieved by the addition of targeting moiety without causing side effects in normal tissues. Many studies into new applications are in progress, including ocular phototherapy using PTT, PDT, and optogenetics . Taken together, the endeavored multidisciplinary research on photonic materials should pave a new way to further technological advances, allowing their practical applications toward futuristic photomedicine.…”

Laser-activated nano-biomaterials for tissue repair and controlled drug release

“…In turn, after excitation with light from a NIR laser, these plasmon resonances happen to relax mainly through nonradiative channels [33]. The interplay of physical and chemical properties of gold nanoparticles gives a number of favourable conditions such as exceptional optical extinction cross sections (about five orders of magnitude higher than those of organic chromophores [29,34]), high stability in the body and thresholds ICG-chitosan film Homogenised tissue before photo-bleaching [33], low toxicity [35,36] and much versatility of conjugation with additional molecules including ligands and drugs. In addition, the potential of particles in a range of size of some tens of nanometres to passively accumulate into tumours after intravenous injection, thanks to their enhanced permeability and retention (EPR), has inspired the use of plasmonic nanoparticles in oncology.…”

“…As a proof of the concept of the possibility to replace organic dyes with gold nanorods, we tested aqueous batches of these nanoparticles with plasmonic bands in the NIR window overlapping the optical absorption of ICG for the laser welding of a model ocular tissue, that is the porcine eye lens capsule [34,58]. This is a connective tissue with high transparency and structural homogeneity.…”