Chitosan IR806 dye-based polyelectrolyte complex nanoparticles with mitoxantrone combination for effective chemo-photothermal therapy of metastatic triple-negative breast cancer.

Chemo-photothermal therapy is one of the emerging therapies for treating triple-negative breast cancer. In this study, we have used ionotropic gelation method to fabricate chitosan and IR806 dye-based polyelectrolyte complex (CIR-PEx) nanoparticles. These nano-complexes were in size range of 125 ± 20 nm. The complexation of IR 806 dye with chitosan improved photostability, photothermal transduction, and showed excellent biocompatibility. Cancer cells treated with CIR-PEx NPs enhanced intracellular uptake within 5 h of incubation and also displayed mitochondrial localization. With the combination of CIR-PEx NPs and a chemotherapeutic agent (i.e., mitoxantrone, MTX), a significant decline in cancer cell viability was observed in both 2D and 3D cell culture models. The chemo-photothermal effect of CIR-PEx NPs + MTX augmented apoptosis in cancer cells when irradiated with NIR light. Furthermore, when tested in the 4 T1-tumor model, the chemo-photothermal therapy showed a drastic decline in tumor volume and inhibited metastatic lung nodules. The localized hyperthermia caused by photothermal therapy reduced the primary tumor burden, and the chemotherapeutic activity of mitoxantrone further complemented by inhibiting the spread of cancer cells. The proposed chemo-photothermal therapy combination could be a promising strategy for treating triple-negative metastatic breast cancer.

Iontophoresis mediated localized delivery of liposomal gold nanoparticles for photothermal and photodynamic therapy of acne.

Acne is one of the common dermatological skin inflammatory conditions. The current therapeutic modalities for the treatment of acne include the administration of antibiotics and anti-inflammatory agents. The rising instance of antibiotic resistance in acne strains has led to the exploration of alternative therapeutic modalities. In the current study, we have employed a liposomal gold nanoparticle entrapping curcumin (Au Lipos Cur NPs) for dual light-mediated therapy for the treatment of acne. These nanoparticles exerted a positive zeta potential that enabled their localized follicular delivery by iontophoresis. The localized deposition of Au Lipos NPs leads to photothermal transduction causing destruction of sebaceous glands. Furthermore, when the nanoparticles were assessed in vitro by sequential irradiation with NIR and blue light, it resulted in significant inhibition of bacterial growth. Thus the dual light-mediated therapy by Au Lipos Cur NPs can form a potential therapeutic modality for the efficient treatment of recurrent acne.

The "nano to micro" transition of hydrophobic curcumin crystals leading to in situ adjuvant depots for Au-liposome nanoparticle mediated enhanced photothermal therapy.

Photothermal therapy (PTT) is emerging as a promising treatment for skin cancer. Plasmon-resonant gold-coated liposome nanoparticles (Au Lipos NPs) specifically absorb Near Infra-Red (NIR) light resulting in localized hyperthermia (PTT). In the current study, curcumin (a hydrophobic anticancer agent) was entrapped in Au Lipos NPs as nanocrystals to act as an adjuvant for the PTT of melanoma. NIR light irradiation on Au Lipos Cur NPs triggered the release of curcumin nanocrystals which coalesce to form curcumin microcrystals (CMCs). An in situ"nano to micro" transition in the crystal state of curcumin was observed. This in situ transition leads to the formation of CMCs. These CMCs exhibited sustained release of curcumin for a prolonged duration (>10 days). The localized availability of curcumin aids in enhancing PTT by inhibiting the growth and mobility of cancer cells that escape PTT. In the in vitro modified scratch assay, the Au Lipos Cur NP + Laser group showed >1.5 fold enhanced therapeutic coverage when compared with the Au Lipos NP + Laser group. In vivo PTT studies performed in a B16 tumor model using Au Lipos Cur NPs showed a significant reduction of the tumor volume along with the localized release of curcumin in the tumor environment. It was observed that the localized release of curcumin enables an immediate adjuvant effect resulting in the enhancement of PTT.