Background: Glutathione (GSH), the primary antioxidant in cells, could fight against oxidative stress. Tumor cells display a higher GSH level than normal cells for coping with the hyperoxidative state, which meets the requirements of enhanced metabolism and vicious proliferation. Therefore, the consumption of GSH will lead to cell redox imbalance and impede life activities. Herein, targeted sorafenib (SFB) loaded manganese doped silica nanoparticle (FaPEG-MnMSN@SFB) was constructed, which could destroy the intracellular redox homeostasis by consuming GSH.

The chemotherapy combined with photothermal therapy has been a favorable approach for the treatment of breast cancer. In present study, nanoparticles with the characteristics of photothermal/matrix metalloproteinase-2 (MMP-2) dual-responsive, tumor targeting, and size-variability were designed for enhancing the antitumor efficacy and achieving “on-demand” drug release markedly. Based on the thermal sensitivity of gelatin, we designed a size-variable gelatin nanoparticle (GNP) to encapsulate indocyanine green (ICG) and doxorubicin (DOX). Under an 808 nm laser irradiation, GNP-DOX/ICG responded photothermally and swelled in size from 71.58 ± 4.28 to 160.80 ± 9.51 nm, which was beneficial for particle retention in the tumor sites and release of the loaded therapeutics. Additionally, GNP-DOX/ICG showed a size reduction of the particles to 33.24 ± 4.11 nm and further improved drug release with the degradation of overexpressed MMP-2 in tumor. In the subsequently performed in vitro experiments, it was confirmed that GNP-DOX/ICG could provide a therapeutic effect that was enhanced and synergistic. Consequently, GNP-DOX/ICG could efficiently suppress the growth of 4T1 tumor in vivo. In conclusion, this study may provide a promising strategy in the rational design of drug delivery nanosystems based on gelatin for chemo-photothermal therapy to achieve synergistically enhanced therapeutic efficacy against breast cancer.

Mesoporous silica nanoparticles (MSNs) have attracted extensive attention as drug delivery systems because of their unique meso-structural features (high specific surface area, large pore volume, and tunable pore structure), easily modified surface, high drug-loading capacity, and sustained-release profiles. However, the enduring and non-specific enrichment of MSNs in healthy tissues may lead to toxicity due to their slow degradability and hinder their clinical application. The emergence of degradable MSNs provided a solution to this problem. The understanding of strategies to regulate degradation and clearance of these MSNs for promoting clinical trials and expanding their biological applications is essential. Here, a diverse variety of degradable MSNs regarding considerations of physiochemical properties and doping strategies of degradation, the biodistribution of MSNs in vivo, internal clearance mechanism, and adjusting physical parameters of clearance are highlighted. Finally, an overview of these degradable and clearable MSNs strategies for biosafety is provided along with an outlook of the encountered challenges.

Background: Methicillin-resistantStaphylococcus aureus(MRSA) biofilm-associated bacterial infection is the primary cause of nosocomial infection and has long been an ongoing threat to public health. MRSA biofilms are often resistant to multiple antimicrobial strategies, mainly due to the existence of a compact protective barrier; thus, protecting themselves from the innate immune system and antibiotic treatment via limited drug penetration.Results: A hierarchically structured hydrogen sulfide (H₂S)-releasing nano-disinfectant was presented, which was composed of a zinc sulfide (ZnS) core as a H₂S generator and indocyanine green (ICG) as a photosensitizer. This nano-disinfectant (ICG-ZnS NPs) sensitively responded to the biofilm microenvironment and demonstrated efficient eradication of MRSA biofilms via a synergistic effect of Zn²⁺, gas molecule-mediated therapy, and hyperthermia. Physically boosted by released H₂S and a near-infrared spectroscopy-induced hyperthermia effect, ICG-ZnS NPs destroyed the compactness of MRSA biofilms showing remarkable deep-penetration capability. Moreover, on-site generation of H₂S gas adequately ameliorated excessive inflammation, suppressed secretion of inflammatory cytokines, and expedited angiogenesis, therefore markedly accelerating the in vivo healing process of cutaneous wounds infected with MRSA biofilms.Conclusion: ICG-ZnS NPs combined with NIR laser irradiation exhibited significant anti-biofilm activity in MRSA biofilms, can accelerate the healing process through deep-penetration and anti-inflammatory effectuation. The proposed strategy has great potential as an alternative to antibiotic treatment when combating multidrug-resistant bacterial biofilms.Graphical