Silk fibroin microspheres with photothermal nanocarrier encapsulation for anticancer drug delivery

Controlled drug release systems are pivotal in optimizing therapeutic outcomes and mitigating side effects in treatment protocols. While traditional delivery vectors such as liposomes, micro/nanoparticles, and microspheres are effective, they often struggle with consistency in drug release rates. This study addresses these issues by integrating stimuli-responsive elements specifically magnetic, thermal, and pH-responsive components into drug delivery systems for precise control. Central to our approach is the use of silk fibroin (SF), chosen for its superior biocompatibility and tunable degradation kinetics. We developed uniform carrier microspheres (CMs) by embedding polydopamine nanoparticles (PDA NPs) into SF microspheres (SFMs) using a custom-designed microfluidic platform. The development process and the application of this platform are detailed, highlighting the precision in control achievable. These CMs showcased enhanced photothermal effects, with the thermal response finely adjustable by altering the PDA NPs concentration, achieving a notable temperature increase of 24.5°C at 7.4 wt% concentration. High drug loading capacity (7.5%) and encapsulation efficiency (91.6%) were achieved, along with a pH-responsive release profile under near-infrared irradiation (NIR), paving the way for targeted anticancer drug delivery systems using the model drug doxorubicin hydrochloride (DOX·HCl). These findings underscore the potential of the developed CMs for external topical application, offering promising prospects for targeted cancer therapy utilizing drug-loaded microspheres.