Near-Infrared Light Induced Phase Transition of Biodegradable Composites for On-Demand Healing and Drug Release

Abstract

Light responsive materials play an important role in many biomedical applications. Despite the great potential, commonly available systems are limited by their toxicity and lack of biodegradability. Here, an efficient light triggered system from safe, biodegradable star-poly(ethylene glycol) (star-PEG) and poly(ε-caprolactone) (PCL) with varying melting points controlled by the length of the CL segments is described. When incorporated with gold nanoshells (GNS) and exposed to near-infrared (NIR) irradiation, matrices temporarily disengage, thus allowing efficient on-demand healing and drug release. The responsiveness of this system to light, with its tailorable physical and healing properties, biocompatibility, biodegradability, and the capability to incorporate drugs and on-demand drug release are all desirable traits for numerous clinical applications.

Recent Advances in Bioplastics: Application and Biodegradation

“…Few examples are available where simplicity of design joint with truly biocompatible and biodegradable materials led to the design of photo-responsive DDS. PEG/PCL biocompatible and biodegradable polymer loaded with gold nanoparticle and triggered by a NIR light driven thermogeneration was shown to be active against NIH3T3 cells in vitro ( Figure 3) [129]. Bupicavaine as a drug model was also successfully tested with this system.…”

“…A paradigm shift of the use of PLA-based materials for waveguide-based technology instead of a DDS photo-responsive nanoparticle was achieved by Nizamoglu and colleagues [130], where photochemical tissue bonding, a carefully designed device to deliver phototerapeutic laser treatment in the subdermal section of a living organism, was used to achieve a 10-fold increase in visible light penetration using a biodegradable and expendable waveguide, which promoted a more efficient closure of the wound when suturing with this technique. [129].…”

“…Polyethylene glycol-polycaprolactone (PEGylated-PCL) micelle loaded with gold nanoparticles to induce apoptosis into NIH3T3 cancer cells in vitro, when stimulated by near infrared radiation (NIR). Freely adapted from Shagan et al 2018[129].…”

Hot Glue Gun Releasing Biocompatible Tissue Adhesive

“…Melting temperatures, measured by differential scanning calorimetry (DSC), increased with molecular weight and ranged between 39 °C for the 6 kDa star‐PCL to 49 °C for the 20 kDa polymer ( Figure A). A similar relation between molecular weight and melting temperature has been reported for other star‐shaped PCL polymers, and has been attributed to differences in semicrystallinity: longer chains tend to form more highly crystalline networks resulting in higher melting temperatures . In downstream experiments, the shortest polymer (6 kDa) was excluded since its melting point, ≈39 °C, is too close to human body temperature, which might interfere with the solidification process.…”

“…To avoid damage to nearby tissue and biologic molecules, the melting point of such a bioadhesive should be least possible above 37 °C (human body temperature) required for solidification in physiological conditions . To synthesize a biomaterial with precise melting point, without compromising biocompatibility and biodegradability, we developed a straightforward synthetic scheme ( Figure ) and produced a library of star‐PCL‐NHS polymers with varying melting points, governed by their length …”