Defective Black Nano-Titania Thermogels for Cutaneous Tumor-Induced Therapy and Healing

Abstract

Current challenges in cutaneous tumor therapy are healing the skin wounds resulting from surgical resection and eliminating possible residual tumor cells to prevent recurrence. To address this issue, bifunctional biomaterials equipped with effective tumor therapeutic capacity for skin cancers and simultaneous tissue regenerative ability for wound closure are highly recommended. Herein, we report an injectable thermosensitive hydrogel (named BT-CTS thermogel) with the integration of nanosized black titania (B-TiO 2−x , ∼50 nm) nanoparticles into a chitosan (CTS) matrix. The B-TiO 2−x nanocrystal exhibits a crystalline/amorphous core− shell structure with abundant oxygen vacancies, which endows the BT-CTS thermogels with simultaneous photothermal therapy (PTT) and photodynamic therapy (PDT) effects under single-wavelength near-infrared laser irradiation, leading to an excellent therapeutic effect on skin tumors in vitro and in vivo. Moreover, the BT-CTS thermogel not only supports the adhesion, proliferation, and migration of normal skin cells but also facilitates skin tissue regeneration in a murine chronic wound model. Therefore, such BT-CTS thermogels with easy injectability, excellent thermostability, and simultaneous PTT and PDT efficacy as well as tissue regenerative activity offers a promising pathway for the healing of cutaneous tumor-induced wounds.

Nanocatalytic Medicine

“…Both in vitro and in vivo results demonstrated that the fabricated B‐TiO 2− x could achieve high therapeutic efficacy against cancer, evidencing the feasibility of such a surface engineering strategy that endowed TiO 2 nanoparticles with broadened light absorption and elevated quantum yield for ROS production. Very recently, Wu and co‐workers have also integrated B‐TiO 2− x with chitosan matrix to fabricate an injectable thermosensitive hydrogel for cutaneous tumor treatment ( Figure ) . Under NIR irradiation, B‐TiO 2− x catalyzes the generation of a considerable amount of ROS to initiate cancer cell death, while Mg 2+ released from the composite thermogels could stimulate the adhesion and proliferation of normal skin cells to accelerate chronic wound closure.…”

“…c) Hematoxylin‐eosin (H&E) staining of sectioned wounds (removal of cutaneous tumor) 14 days after various treatments. a–c) Reproduced with permission . Copyright 2019, American Chemical Society.…”

Piezocatalytic Tumor Therapy by Ultrasound‐Triggered and BaTiO3‐Mediated Piezoelectricity

“…[ 18 ] To verify the injectability in physiological environment, the rheological measurement of the blank thermogel (Gel) and the thermogel loaded with T‐BTO (T‐BTO‐Gel) were conducted to determine the transformation temperature from liquid‐like status to elastic gel‐like matrix, which are 36.5 and 35.6 °C (Figure S7a,c, Supporting Information). [ 18c,19 ] The time dependence of the storage/loss modulus was also investigated and phase transformation was observed within 30 min at the simulated physiological temperature (37 °C, Figure S7b,d,e, Supporting Information). After co‐incubating in the simulated body fluid (SBF) for seven days, no significant change occurs in the appearance and the microstructure in the cross‐sectional image of the T‐BTO‐Gel after three US irradiation cycles, indicating the high US stability of the thermogel matrix (Figure S8, Supporting Information).…”

Facile transdermal delivery of upconversion nanoparticle by iontophoresis-responsive magneto-upconversion oleogel

“…Owing to the superior tissue penetration ability of NIR laser source (e.g. 808 nm, 980 nm, etc), success in non-invasive photochemical tissue bonding and tumor-induced wound healing has been achieved [6][7][8]. Such reports indicate the enormous potential of using NIR driven upconversion nanoparticle (UCNP) in non-invasive treatment of sub-cutaneous cancer and skin diseases.…”