Subcellular-Targeted Near-Infrared-Responsive Nanomedicine with Synergistic Chemo-photothermal Therapy against Multidrug Resistant Cancer

Unlocking the Mitochondria for Nanomedicine-based Treatments: Overcoming Biological Barriers, Improving Designs, and Selecting Verification Techniques

Enhanced targeting approaches will support the treatment of diseases associated with dysfunctional mitochondria, which play critical roles in energy generation and cell survival. Obstacles to mitochondria-specific targeting include the presence of distinct biological barriers and the need to pass through (or avoid) various cell internalization mechanisms. A range of studies have reported the design of mitochondrially-targeted nanomedicines that navigate the complex routes required to influence mitochondrial function; nonetheless, a significant journey lies ahead before mitochondrially-targeted nanomedicines become suitable for clinical use. Moving swiftly forward will require safety studies, in vivo assays confirming effectiveness, and methodologies to validate mitochondria-targeted nanomedicines' subcellular location/activity. From a nanomedicine standpoint, we describe the biological routes involved (from administration to arrival within the mitochondria), the features influencing rational design, and the techniques used to identify/validate successful targeting. Overall, rationally-designed mitochondria-targeted-based nanomedicines hold great promise for precise subcellular therapeutic delivery.

Near-Infrared Responsive Synergistic Chemo-Phototherapy from Surface-Functionalized Poly(ε-caprolactone)-Poly(d,l-lactic-co-glycolic acid) Composite Nanofibers for Postsurgical Cancer Treatment

The combination of hyperthermia and chemotherapy has attracted significant attention in local cancer treatment following surgical resection. Pyrrole is a potent photothermal agent that can induce a temperature rise at different concentrations in the surrounding medium by absorbing near-infrared radiation (NIR). In this study, poly(ε-caprolactone) (PCL) and poly (d,l-lactic-co-glycolic acid) (PLGA) were used to make nanofibers using the electrospinning process. Then, pyrrole in different concentrations of (0.2, 0.4, and 0.6) M was attached to the surface of PCL-PLGA fiber mats by in situ polymerization, which was confirmed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) analysis. A concentration-dependent local temperature rise was observed using a FLIR camera under near-infrared (NIR) laser irradiation. For the hyperthermia effect, pyrrole concentration (0.06 M) was used for in vitro drug release studies and cell viability assays because under NIR irradiation (2 W/cm², 3 min), it increased the local temperature to around 45 °C. In vitro drug release studies confirmed that NIR irradiation increased the diffusion rate of doxorubicin (DOX) by increasing the environmental temperature above the glass transition temperature of PLGA. In vitro cytotoxicity experiments further confirmed that PCL-PLGA-DOX/PPy fiber mats showed an enhanced inhibitory effect against CT26 and MCF7 cells by the combination of hyperthermia and chemotherapy.