Dermal extracellular matrix gelatin delivering Prussian blue nanoparticles to relieve skin flap ischemia.

The survival rate of flap is a crucial factor for determining the success of tissue repair and reconstruction. Flap transplantation surgery often leads to ischemic and reperfusion injury, causing apoptosis and tissue necrosis, which significantly reduces the survival rate of flap. To address this issue, we developed a porcine skin decellularized matrix gel nanocomplex loaded with alprostadil (Alp) in Prussian blue nanoparticles (PB NPs) called Alp@PB-Gel. This gel not only maintained the cell affinity of the extracellular scaffold but also exhibited a high degree of plasticity. In vitro assays demonstrated that Alp@PB-Gel possessed antioxidant activity, scavenging ROS ability, and effectively promoted the angiogenesis and migration of human vascular endothelial cells (HUVECs) by stimulating the proliferation of vascular epithelial cells and fibroblasts. In vivo assays further confirmed that Alp@PB-Gel could effectively alleviate necrosis in the early and late stages after surgery, downregulate the levels of NLRP3 and CD68 to inhibit apoptosis and attenuate inflammation, while upregulate the levels of VEGF and CD31 to promote vascular tissue regeneration. Moreover, Alp@PB-Gel exhibited excellent cell affinity and biocompatibility, highlighting its potential for clinical application.

Near-infrared laser-assisted Ag@Chi-PB nanocompounds for synergistically eradicating multidrug-resistant bacteria and promoting diabetic abscess healing.

Chronic wound infections, particularly multidrug-resistant microbe-caused infections, have imposed severe challenges in clinical administration. The therapeutic effectiveness of the current strategy using conventional antibiotics is extremely unsatisfactory. The development of novel treatment strategies to inhibit the infections caused by multidrug-resistant bacteria is highly desired. In this work, based on the combination of nanocompounds with the assistance of NIR laser, an antibacterial strategy was designed for MRSA-infected abscesses in diabetic mice. The nanocompounds named Ag@Chi-PB were prepared by using chitosan-coated Prussian blue (PB) as a nanocarrier for silver nanoparticles anchoring. Combined with near-infrared (NIR) laser, the nanocompounds were more efficient at killing Escherichia coli (E. coli) and Methicillin-resistant staphyllococcus aureus (MRSA) in vitro. Notably, MRSA was significantly removed in vivo and promoted diabetic abscess healing by the combined therapy of this nanocompound and NIR laser, owing to the synergistic antibacterial effect of photothermal therapy and release of Ag+. Meanwhile, the nanocompound showed satisfactory biocompatibility and superior biosafety. Collectively, the combination therapy of this nanocompound with the assistance of NIR laser may represent a promising strategy for clinical anti-infection.

Assessing Phytogenic and Chemogenic Silver Nanoparticles for Antibacterial Activity and Expedited Wound Recuperation.

Green silver nanoparticles (AgNPs) possess tremendous promise for diverse applications due to their versatile characteristics. Coriander and other plant extracts have become popular for greenly synthesizing AgNPs as an economical, biocompatible, cost-effective, and environmentally beneficial alternative to chemical processes. In this study, we synthesized AgNPs from coriander leaves and evaluated their antibacterial, anti-inflammatory, antioxidant, and wound-healing acceleration properties in comparison to chemically synthesized AgNPs. The zeta potentials of AgNPs extracted from green and chemical processes were -32.4 mV and -23.4 mV, respectively. TEM images showed a cuboidal shape of green and chemical AgNPs with a diameter of approximately 100 nm. The FTIR spectra of green AgNPs showed an extreme absorption peak at 3401 cm-1, which signifies O-H stretching vibrations, typically linked to hydroxyl groups. In vitro results elaborated that AgNPs from coriander exerted a stronger effect on anti-Klebsiella pneumoniae (KP) through interrupting cell integrity, generating ROS, depleting ATP, and exhibiting significant antioxidant activity, compared with AgNPs synthesized chemically. In vivo experiments showed that AgNPs from coriander, as opposed to chemically manufactured AgNPs, greatly accelerated the healing of wounds contaminated with Klebsiella pneumoniae bacteria by effectively eliminating the bacteria on the wounds and stimulating skin regeneration and the deposition of dense collagen. In vivo assays further demonstrated that green AgNPs effectively enhanced Klebsiella pneumoniae-infected wound healing by extenuating local inflammatory responses and up-regulating VEGF and CD31 expression. In conclusion, green AgNPs significantly alleviated the inflammation without significantly harming the organism.

Prussian blue nano-enzyme-assisted photodynamic therapy effectively eradicates MRSA infection in diabetic mouse skin wounds.

Antibiotic therapy can induce the generation of severe bacterial resistance, further challenging the usability of currently available drugs and treatment options. Therefore, it is essential to develop new strategies to effectively eradicate drug-resistant bacteria. Herein, we have reported a combinational strategy for the eradication of drug-resistant bacteria by using chlorin e6 (Ce6) loaded Prussian blue nanoparticles (PB NPs). This nanocomplex showed strong catalase activity and photodynamic properties. In vitro experiments demonstrated that CPB-Ce6 NPs effectively kill MRSA by generating ROS under laser irradiation. Meanwhile, the nano-enzyme activity of CPB NPs can decompose H2O2 in the bacterial microenvironment to upregulate the O2 level, which in turn alleviates hypoxia in the microenvironment and improves the antibacterial effect of PDT. In vivo results demonstrated that CPB-Ce6 NPs with laser irradiation effectively cleared MRSA and promoted infected wound repair in a diabetic mouse model and normal mice through upregulating VEGF. Moreover, CPB-Ce6 NPs showed excellent biosafety profiles in vitro and in vivo. From our point of view, this PDT based on PB NPs with nano-enzyme activity may provide an effective treatment for infections associated with drug-resistant microbes and tissue repair.