Laser-activated chitosan films doped with gold nanorods as adhesives for biomedical applications

Stimuli-responsive polymeric biomaterials have attracted much attention for their prospective application in several fields including biomedicine, biotechnology and biosensing. We have recently engineered an hybrid bioadhesive consisting in a chitosan film doped with gold nanorods (GNRs) that can be activated by near-infrared (NIR) laser light [1,2]. These films ( 0.8 cm diameter, 40 ?m thickness) are insoluble, flexible, resistant and stable in a physiological environment. The use of GNRs provides amplified optical absorbance of the laser light due to efficient plasmon bands in the NIR window, where tissue components and chitosan are mostly transparent. Upon laser irradiation a well-localized photothermal effect can thus be produced in the film, which is in turn stimulated to produce adhesion with a proximal tissue surface (e.g. arterial wall, tendon, lens capsule). Optimal irradiation conditions were observed with laser pulses in the millisecond timescale and about 1 W power, which proved reliable and reproducible. This technology may enable a number of key applications in medicine including tissue repair, wound dressing and drug delivery. [1] Matteini P et al. Chitosan films doped with gold nanorods as laser-activatable hybrid bioadhesives. Adv Mater 22 4313 (2010) [2] Matteini P et al. Hybrid nanocomposite films for laser-activated tissue bonding. J Biophotonics 5 868 (2012)