Titanium nanosheet as robust and biosafe drug carrier for combined photochemo cancer therapy.

Two-dimensional (2D) Titanium nanosheets (Ti NSs) have shown many excellent properties, such as nontoxicity, satisfactory photothermal conversion efficacy, etc. However, the biomedical applications of Ti NSs have not been intensively investigated. Herein, we synthesized a multifunctional Ti NS drug delivery system modified with polydopamine/polyethylene glycol (Ti@PDA-PEG) and applied simultaneously for photothermal therapy and chemotherapy. Doxorubicin (DOX) was utilized as a model drug. Ti@PDA-PEG NS shows an ultrahigh antitumor drug DOX loading (Ti@PDA-PEG-DOX). The prepared Ti@PDA-PEG-DOX NS as robust drug delivery system demonstrates great stability and excellent multi-response drug-release capabilities, including pH-responsive and near-infrared -responsive behavior and obviously high photothermal efficiency. Both in vitro and in vivo experimental results have shown high biosafety and outstanding antitumor effects. Therefore, this work exhibits the enormous potential of a multifunctional platform in the treatment of tumors and may stimulate interest in the exploration of other new 2D nanomaterials for biomedical applications.

Targeted Chemotherapy for Breast Cancer Using an Intelligent Doxorubicin-Loaded Hexapeptide Hydrogel.

Self-assembling peptide hydrogels have a high water content, good biocompatibility and have become a competitive research object in the fields of tissue engineering, cancer treatment and drug delivery. In our research, a hexapeptide with high pH sensitivity was designed and synthesized by utilizing a solid-phase synthesis method. Under physiological conditions, the peptide could self-assemble into a hydrogel. When it reached the tumor acidic microenvironment, the peptide was degraded and doxorubicin was released to exert its antitumor effect. A series of physicochemical properties were investigated, including gelling ability, secondary structure, micromorphology, rheological properties and drug release studies. The results illustrated that PIDO peptide hydrogel has good pH responsiveness and injectability. In vitro cytotoxicity experiments and in vivo antitumor experiments showed that PIDO peptide hydrogel has a highly effective therapeutic effect on tumor cells and is less toxic to normal tissues. Our research provides a promising option for targeted drug delivery and sustainable release.

Injectable pH and redox dual responsive hydrogels based on self-assembled peptides for anti-tumor drug delivery.

Traditional anti-tumor drugs still have some shortcomings, such as low solubility, poor selectivity and poor bioavailability, which decrease their anti-tumor efficacy and aggravate systemic toxicity and side effects. In this paper, pH/redox dual responsive IC1-R peptide hydrogels were designed as drug delivery materials for the anti-tumor drug paclitaxel (PTX). The physical and chemical properties of drug-loaded IC1-R peptide hydrogels were characterized by pH/redox sensitivity, drug release, physical description, encapsulation rate, circular dichroism, electron transmission microscopy, and rheological tests. In vitro cytotoxicity and in vivo efficacy were studied to evaluate the anti-tumor efficacy of the PTX-loaded hydrogel. IC1-R was found to have high sensitivity to pH/redox conditions, and the encapsulation rate can reach more than 98% at different PTX dosages. The structure of the IC1-R peptide was found to be a ß-sheet under neutral conditions, which met the requirement for nanofiber network formation. Transmission electron microscopy and rheology tests confirmed that the suitable meshwork structure and improved mechanical and injectable properties of this hydrogel. In vitro and in vivo results showed that the blank hydrogel had good biological safety and confirmed the pH/redox sensitive properties of IC1-R-PTX, which allowed sustained delivery of the drug and enhanced tumor inhibition. In conclusion, this kind of PTX-loaded peptide hydrogel, which was formed in vitro, can be injected into tumors and can continuously and slowly release anti-tumor drugs under the stimulation of the tumor microenvironment to achieve the best anti-tumor effect and reduce toxicity and side effects. This biofunctional material has broad prospects in the field of drug delivery.

Redox-Sensitive Ultrashort Peptide Hydrogel with Tunable Mechanical Properties for Anti-Tumor Drug Delivery.

In this study, we report a new ultrashort peptide (LOC), which forms a redox-sensitive hydrogel after cross-linking with the mild oxidant H2 O2 and used it for tumor-targeted delivery of doxorubicin hydrochloride (DOX). LOC gelled within a few minutes in low-concentration H2 O2 solution. The concentration of H2 O2 significantly altered the gelation time and mechanical properties of the hydrogel. The in vitro micromorphology, secondary structure and rheology characterization of cross-linked hydrogels confirmed the sensitivity and injectability to reducing agent. The cross-linked hydrogel had a strong drug loading capacity, and the drug was released in a GSH concentration-dependent manner, following the Fick diffusion model. In addition, the cross-linked hydrogel showed no cytotoxicity to normal fibroblasts, and no damage to the subcutaneous tissue of mice was observed. In vitro cytotoxicity experiments showed that the DOX-hydrogel system exhibited good anti-cancer efficacy. In vivo studies using 4T1 tumor-bearing mice showed that the DOX-hydrogel system had a significant inhibitory effect on tumors. Therefore, the newly designed redox-sensitive hydrogel can effectively enhance the therapeutic efficacy of DOX and reduce toxicity, making it an attractive biological material.